(Download PDF) Lumbar Interbody Fusions 1St Edition Edition Sunil Manjila Full Chapter PDF
(Download PDF) Lumbar Interbody Fusions 1St Edition Edition Sunil Manjila Full Chapter PDF
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Lumbar Interbody
Fusions
Sunil V. Manjila, MD
Staff Neurosurgeon
McLaren Bay Region Medical Center
Bay City, Michigan, USA
Thomas E. Mroz, MD
Director, Center for Spine Health
Director, Clinical Research
Center for Spine Health
Departments of Orthopaedic and Neurological Surgery
Cleveland Clinic
Cleveland, Ohio, USA
Michael P. Steinmetz, MD
Professor and Chairman
Department of Neurosurgery
Cleveland Clinic Lerner College of Medicine
Cleveland Clinic
Cleveland, Ohio, USA
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© 2019, Elsevier Inc. All rights reserved.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or any information storage and retrieval system, without permission in writing
from the publisher. Details on how to seek permission, further information about the Publisher’s permissions poli-
cies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing
Agency, can be found at our website: www.elsevier.com/permissions.
This book and the individual contributions contained in it are protected under copyright by the Publisher (other than
as may be noted herein).
Chapter 13 Pre-psoas (oblique) lateral interbody fusion at L5/S1: Copyright for all figures and video clips retained
by Medtronic, Inc.
Notices
Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any
information, methods, compounds or experiments described herein. Because of rapid advances in the medical sci-
ences, in particular, independent verification of diagnoses and drug dosages should be made. To the fullest extent
of the law, no responsibility is assumed by Elsevier, authors, editors or contributors for any injury and/or damage
to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of
any methods, products, instructions, or ideas contained in the material herein.
ISBN: 978-0-323-47663-8
E-ISBN: 978-0-323-49741-1
Printed in China
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Preface
“No matter what measures are taken, doctors will sometimes fal- implant/screw options and role of spinous process plates, facet
ter, and it isn’t reasonable to ask that we achieve perfection. What screws, and pedicle screws in offering spinal stability. Finally, Sec-
is reasonable is to ask that we never cease to aim for it.” tion V provides an overview of revision interbody fusions, thoracic
― Atul Gawande, Complications: A Surgeon’s and lumbar overlap diseases, and evidence-based reports on lum-
Notes on an Imperfect Science bar interbody fusions. This practical template gives a 360-degree
approach to lumbar spine surgery, providing ample insights and
It is a distinct honor and privilege to present the inaugural edition tenets to deal with complex lumbar spine procedures in vexing
of Lumbar Interbody Fusions by Manjila, Mroz, and Steinmetz, clinical situations. The authors have infused their vast clinical and
showcasing the techniques and nuances in lumbar spine surgery surgical experience into what makes for a well-choreographed,
that can improve both safety and efficacy in our operating rooms. rehearsed operation, notably in an era where “10,000 hours of
This highly technical and contextualized treatise provides a unique practice to perfection” is cumbersome with current residency
and state-of-the-art “single-stop shop” for the reader, whether a training restrictions.
novice resident or an expert practitioner, perusing all the major We also thank the publishers at Elsevier for their boundless
lumbar interbody fusion techniques in its sum and substance. and unfailing support as well as tireless assistance in bringing out
This book will truly serve as a vade mecum procedural guide, this volume. I would personally like to thank Sharon Nash (Senior
and a perfect addendum to the conventional pedagogical texts in Content Development Specialist), Belinda Kuhn (Senior Content
spine surgery. This book has five intuitive sections and spans 232 Strategist), and Beula Christopher King (Senior Project Manager)
pages. Section I provides a primer to the subject with relevant and for their continued interactions and diligent interventions in
updated clinical studies, while Section II provides an overview of bringing out this magnum opus in a timely manner. We welcome
pertinent surgical anatomy and intraoperative imaging. Section your thoughtful comments, suggestions, and criticisms to improve
III discusses the surgical options of lumbar interbody fusions with subsequent editions, as we truly believe that surgical training is
indications, techniques, pearls and pitfalls, with complication a mesmerizing art and science, ever-changing and evolving with
avoidance and management. Section IV presents contemporary time and ensuing needs of both patients and the providers.
updates on adjunct instrumentation, implant biomaterials, and
biologic options in lumbar fusion, with subsections on integrated Sunil V. Manjila, MD
viii
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List of Contributors
Jason Cohen, BS
Albert Einstein College of Medicine
Bronx, New York, USA
ix
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x List of Contributors
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List of Contributors xi
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Acknowledgments
I would like to acknowledge all the outstanding contributing I would like to acknowledge all of my mentors. Their training
authors who volunteered their time, effort, and energy in mak- and guidance have made this project possible. I would like to fur-
ing this work an astounding success. I appreciate all the ideas, ther acknowledge present and past partners, collaborators, fellows,
suggestions, and guidance from the editorial/publishing team and residents, and medical students.
content developers of Elsevier, and I dedicate this volume to the
esteemed readers who will make best use of its contents for the Michael P. Steinmetz, MD
welfare and well-being of our patients all across the world.
Sunil V. Manjila, MD
xii
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I would like to dedicate this book to my mentors,
teachers, benefactors, friends, and family, especially
my loving sons—Nihal Manjila and Rehan Manjila.
Sunil V. Manjila, MD
xiii
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S E C T I ON 1 Lumbar Interbody Fusions – A Primer
1
General Indications and
Contraindications
SHANKAR A. KUTTY AND SUNIL V. MANJILA
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2 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
this background to assess the safety and utility of BMP-2 and The benefit of surgery has been demonstrated repeatedly in vari-
found that the incidence of retrograde ejaculation and neurologic ous trials, with the Spine Patient Outcomes Research Trial being
complications were equal in both autograft and BMP-augmented the most significant study to support surgery for these patients.16–18
ALIF surgeries. It also demonstrated a small increased relative The best surgery indicated in each case of degenerative spondy-
risk of malignancy with the use of rhBMP-2 in posterolateral lolisthesis and whether these patients need spinal fusion are still
lumbar surgeries. However, the absolute risk was very low and open to debate. Presence of spondylolisthesis in patients with
therefore clinically insignificant. No difference was found between lumbar canal stenosis was considered an indication for fusion sur-
rhBMP-2 and iliac crest graft, but there was a higher rate of ecto- gery, even in stable cases where the slip is less than 3 mm. Recent
pic bone formation in these procedures. Based on these findings, studies have shown that in the United States approximately half
judicious use of BMP is now advocated in posterior lumbar sur- the patients with lumbar spinal stenosis and 96% of those with
geries. In transforaminal lumbar interbody fusion (TLIF), a high degenerative spondylolisthesis undergo spinal fusion.19–21 This
risk of postoperative radiculitis has been reported; hence, the use view has been challenged by recent studies from Sweden and the
of BMP in these cases is not encouraged.11a The use of bone mar- United States, which found that the benefit of fusion in patients
row aspiration from the exposed lumbar vertebral bodies during with stable spondylolisthesis and lumbar spinal stenosis was mar-
the surgery, and then using this aspirate as graft material has been ginal at best. The Swedish Spinal Stenosis Study was a randomized
recently reported.11b This overcomes the graft site complications controlled trial of 247 patients who were divided into fusion and
as well as the problems associated with the use of BMP-2. Further nonfusion groups, with each group containing at least 40 patients
research is ongoing about the use of growth differentiation factor with and without degenerative spondylolisthesis (at least 3 mm).
5, also known as BMP-14, as an osteogenetic material. At 2- and 5-year follow-ups, no significant difference in outcomes
were found in the two groups. The rates of reoperation were also
remarkably similar, raising a question about the need for fusion
Interbody Fusion: A Primer and Recent in degenerative spondylolisthesis. In this study, the preoperative
Literature evaluation did not include flexion-extension x-ray studies; if this
had been done and patients with demonstrable instability were
Over the years a number of approaches have been developed assigned to the fusion group, the results in the nonfusion group vis
for LIF, namely posterior, anterior, axial, transforaminal, lateral, à vis repeated surgery may have been even better.22
extreme lateral, and oblique lateral. In keeping with the trend However, another study, albeit smaller, published in the same
toward minimally invasive surgeries, reports of percutaneous issue of New England Journal Medicine mentioned above, found
attempts at surgical stabilization of the lumbar spine first appeared a minimally improved physical outcome in patients who had
more than two decades ago.12,13 Although posterior lumbar undergone fusion surgery at 2, 3, and 4 years. This was not con-
fusion via minimally invasive techniques has become common- sidered sufficiently significant to support the higher cost in terms
place, endoscopic surgeries for TLIF require special training. Even of financial burden, blood loss, operative time, and hospital stay in
though the exact procedure that is chosen for a particular patient these patients. Counter-intuitively the reoperation rate was higher
may depend on a number of factors, such as the exact pathol- in patients who did not undergo fusion even though this study
ogy and surgical anatomy of a particular patient and the surgeon’s had excluded patients with instability as demonstrated by flexion-
preference, the pathologies that need surgical fusion of the lumbar extension x-ray study.23 This apparent confounding factor may be
spine remain broadly the same. These include degenerative dis- related to the physician approach in the two countries where the
eases, spinal trauma, deformity correction, infections, and tumors. studies were done, with physicians in the United States tending
Interbody fusion is indicated in a subgroup of patients in to offer revision-with-fusion to those patients who had pain after
whom the surgical approach to treat a pathology results in spinal decompression alone, whereas the threshold for offering revision
instability or if preexisting instability is present. Spondylolisthe- surgery to a patient with pain, who had already undergone spinal
sis, the most common indication for interbody fusion, is defined stabilization, may be much higher. The current evidence seems to
as the horizontal translation of a vertebral body over an adjacent point to the need for fusion only in those with unstable degen-
one and was divided into five groups by Newman and Stone,15 erative spondylolisthesis as shown on flexion-extension x-ray films,
namely, congenital, degenerative, spondylolytic, traumatic, and patients with destruction of vertebral bodies owing to trauma,
pathologic. Spondylolisthesis is graded depending on the length infection or tumors, and spinal deformities such as other variants
of the vertebral body that is not in contact with the adjacent ver- of spondylolisthesis or scoliosis. The need for fusion in neural-
tebra (extent of slippage). In grade I spondylolisthesis, the area of foraminal stenosis owing to postsurgical disk prolapse is another
noncontact is less than 25% of the anteroposterior diameter of contentious area, with no evidence to support improved outcome
the vertebral body on a lateral x-ray study, whereas in grade II, with fusion.24
the slip is between 26% and 50%. When the area of noncontact In isthmic spondylolisthesis, there is a fracture of the pars
is between 51% and 75%, it is called grade III; in grade IV, the interarticularis or isthmus, which is the area of the vertebra where
slip is between 76% and 100%. A greater than 100% slip, where the lamina and inferior articular process join the pedicle and the
the adjacent vertebral bodies are lying totally separated from each superior articular process. These cases often occur in a patient
other, is designated grade V, or spondyloptosis. Grades I and II population that is younger than the typical patient with degen-
are considered low grade, whereas the rest are designated as high- erative spondylolisthesis, which is common in the third to fifth
grade spondylolisthesis. The degenerative variant is usually seen decades. The management strategy is similar, with a 3-month trial
in women over the age of 50 years. Low-grade lesions are com- of conservative therapy before opting for surgical management,
monly treated conservatively, and surgery is reserved for those even though some studies have shown a better outcome for sur-
patients who fail to respond or for those who have neurologic gery in these patients.25,26 Even in this case, multiple surgical tech-
deterioration. niques are described to treat isthmic spondylolisthesis, depending
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CHAPTER 1 General Indications and Contraindications 3
on many factors such as lateral foraminal compression, fusion of stenosis resulting in neurogenic claudication rather than radiculo-
facets, grade of listhesis, and expertise of surgeon. pathic symptoms, a TLIF would be a better option.
AxiaLIF can be used if central canal stenosis is not significant,
and the foraminal compression does not cause symptomatic radicu-
Preoperative Factors Influencing Outcome of lopathy. With a predominantly unilateral radiculopathy, a TLIF with
Spinal Fusion wide facetectomy at the side of radiculopathy can be used, with facetal
decompression along the symptomatic side. If the surgeon feels that
Although appropriate patient selection and an impeccable tech- an indirect foraminal decompression is sufficient to treat radiculopa-
nique go far in ensuring the success of spinal stabilization surger- thy, a direct lateral (DLIF/lateral lumbar interbody fusion [XLIF]) can
ies, a number of comorbid conditions or extraneous factors, such be used. There is always a concern about using stand-alone techniques
as diabetes mellitus, osteoporosis, and smoking, may affect a good with ALIF, AxiaLIF, and direct lateral approaches, which then would
outcome. Patients with diabetes mellitus have a much higher rate of require adjunct instrumentation posteriorly with pedicle screws, facet
complications following any spinal surgery, with surgical site infec- screws, or cortical/corticopedicular screw placement at those levels.
tions accounting for a majority of problems.27 A study in 2003 by In reoperations, the following factors must be considered while
Glassman et al.28 showed that the overall complication rates in dia- planning the surgery. Avoid dissecting through the old surgical scar
betic patients were over 50%, whereas it was only 21% in controls. if possible; for example, if there is recurrence after multiple posterior
Nonunion rates in the diabetic patients ranged between 22% and approaches, an ALIF or DLIF can be used, unless the old hard-
26%, whereas it was 5% in controls.28 A more recent study by Guz- ware needs to be revised owing to fracture. A fractured/displaced
man et al.29 showed that for diabetic patients the mean length of L4-5 DLIF graft can removed by repeat DLIF or ALIF as the cage
stay increased (∼2.5 d), costs were greater (1.3-fold), and there was a is large, whereas a combined TLIF or posterior lumbar interbody
greater risk of inpatient mortality (odds ratio = 2.6, P < .0009). The fusion (PLIF) might be needed to get the fragmented cage if it has
ability of cigarette smoke to inhibit fusion was demonstrated in ani- slipped below the level of disk space or is compressing the axilla of
mal studies and fusion rates following surgery have also been found nerve root.2 Always anticipate cerebrospinal fluid leak from a dural
to be lower in patients who smoked. Cessation of smoking at least 6 tear owing to severe epidural fibrosis from prior surgery, in which
months prior to a planned surgery may overcome this risk.30,31 Con- case an open approach is preferred over minimally invasive trans-
comitant rheumatoid arthritis can also increase the risk of complica- tubular retractors. It is easier to follow the normal dura mater with
tions, such as surgical site infections and implant failure, but fusion an open or mini-open approach compared to transtubular vision.3
rates in patients with rheumatoid arthritis have been reported to be Patients with failed back syndrome are advised to have an electro-
comparable to that of controls.32 Osteoporosis is known to increase myography (EMG) to evaluate residual deficits from prior surgery
the risk of implant failure and fractures and should be medically to prognosticate on expected neurologic recovery.4 Always review
managed prior to, or concurrent with, surgery. Bone density index the existing hardware using a computed tomography scan, rather
(bone densitometry) prior to an elective surgery in a patient at high than a magnetic resonance image of the lumbosacral spine to rule
risk can assess the chance of graft failure and vertebral body osteo- for fractured implants or haloing around screws (nonunion) or graft
porotic collapse. High risk patients undergoing elective surgery can dislodgement.5 Always verify the sagittal/coronal balance (using a
be assessed by an endocrinologist, as the management strategies of full scoliosis film, if needed) and the levels adjacent to the symptom-
these patients are complex and include not only the use of calcium atic one (dynamic x-ray study of flexion and extension).
and vitamin D replacement, but also administration of alendronate, Continuous EMG and somatosensory evoked potential (SSEP)
parathyroid hormone, calcitonin and raloxifene,33,34 with use of a monitoring during the surgery may be useful in reducing the risk of
post-operative external bone stimulator. complications caused by overzealous manipulation.35–37a The lat-
est published guidelines on the use of intra-operative monitoring
Tenets of Interbody Fusion has focused attention on the absence of level I evidence regarding
the ability of intraoperative monitoring to prevent (as opposed to
The five basic tenets that govern the type of interbody fusion are (1) diagnosing) injury to the spinal cord during surgery.37b We would
the presence and extent of spondylolisthesis; (2) the need for uni- however, advise a set of electrophysiologic monitoring before and
lateral or bilateral neural foraminal decompression; (3) the presence after the patient is positioned prone or lateral, especially the latter
of coexistent central canal stenosis requiring decompression; (4) the after breaking/bending the operating table which causes stretch-
loss of coronal and sagittal balance in relation to the level of disease; ing of the psoas muscle. It may be necessary to monitor the upper
and (5) the presence of prior surgery at the same level or adjacent lumbar plexus in selected cases.
levels with or without instrumentation and/or interbody grafts. Each case should be individually assessed for safety and fea-
Symptomatic low-grade spondylolisthesis is by far the most sibility of each approach; for example, if ALIF in a young male
common indication for interbody fusion in the lumbar spine. patient runs the risk of retrograde ejaculation, XLIF graft, which
Careful selection of approaches must be directed by goal, lateral- migrated into the central canal, can be retrieved only by an XLIF
ization of clinical signs, loss of curvature, and prior surgery, and approach because of the larger footprint of the cage. In osteopenic
these must be in relation to the age, gender, and medical condition cases with fractured pedicles, an adjunct posterior support can be pro-
of the patient. With significant spondylolisthesis and both neural vided by facet screws, laminar clamps, or even interspinous clamps,
foramina at lower lumbar levels needing to be decompressed, an depending on the presence of canal stenosis and features of spinal
ALIF can be used, especially if there is no canal stenosis. ALIF is anatomy on imaging. It is important for surgeons to be familiar
useful for correcting listhesis, especially if the slippage is the cause with these multiple interbody fusion techniques and specific implant
of central, lateral recess, or foraminal stenosis, as against signifi- retrieval methods in graft failures, as one could potentially encounter
cant ligamentum flavum hypertrophy with associated large hyper- a complication from any of these approaches (e.g., graft migration,
trophic facets. If the patient has circumferential soft tissue canal nonunion, osteomyelitic collapse) in the years to come (Figs. 1.1–1.3).
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4 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
A B
C D
• Fig. 1.1 A–C. Patient with recurrent severe backache and right radiculopathy; computed tomography
(CT) scan images of failed fusion L5-S1, graft subsidence, and nonunion. D–F. Postoperative CT scan
showing removal of old cage, new AxiaLIF rod at L5-S1 with pedicle screw fixation. (Courtesy Jonathan
Pace, MD, Department of Neurosurgery, Case Western Reserve University, Cleveland, Ohio and David J.
Hart, MD, Department of Neurosurgery, Wake Forest University Baptist Medical Center, Winston-Salem,
North Carolina.)
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CHAPTER 1 General Indications and Contraindications 5
E F
• Fig. 1.1, cont’d
A B
• Fig. 1.2 A–C. Patient with refractory postoperative back pain, computed tomography (CT) scan of
spine showing haloing around screws at L4-5 level bilaterally, more on the left with a displaced interbody
cage. D–F. Postoperative CT scan showing repositioned L4-5 graft, with bigger graft size and a larger
diameter pedicle screws. (Courtesy Jonathan Pace, MD, Department of Neurosurgery, Case Western
Reserve University, Cleveland, Ohio and David J. Hart, MD, Department of Neurosurgery, Wake Forest
University Baptist Medical Center, Winston-Salem, North Carolina.)
Continued
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6 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
C D
E F
• Fig. 1.2, cont’d
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CHAPTER 1 General Indications and Contraindications 7
B D
• Fig. 1.3 A–C. Adjacent level disease: Patient with midlumbar backache (prior L3-4 direct lateral fusion
with plate, backed with pedicle screws) and new preoperative computed tomography (CT) scan showing
a retropulsed and migrated prior L2-3 interbody cage. D–F. Postoperative CT scan showing replacement
of a larger graft at L2-3 level via direct lateral approach, with pedicle screws with dramatic relief of symp-
toms. (Courtesy Jonathan Pace, MD, Department of Neurosurgery, Case Western Reserve University,
Cleveland, Ohio, and David J. Hart, MD, Department of Neurosurgery, Wake Forest University Baptist
Medical Center, Winston-Salem, North Carolina.)
Continued
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8 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
E F
Complications Following Lumbar Interbody of postoperative deficits would mandate an emergent computed
Fusion Surgery tomography scan to rule out hardware failure, malposition, frac-
ture, or migration—treatable causes.44 Computed tomography
Acute and delayed complications of any spinal surgery may be or magnetic resonance imaging could be used to assess surgical
associated with LIFs as well. The most devastating complication, site hematoma, cerebrospinal fluid leak, and pressure on neural
of course, is death, and mortality rates following spine surgery structures. The complications specific to each LIF technique are
have been reported to be between 0.15% and 0.29%.38,39 Surgi- extensively described in Chapter 2.
cal site infections may be superficial or deep, and may necessitate Deep vein thrombosis has been reported to occur in as many
prolonged antibiotic therapy or even the removal of implants.40 as 15% to 17% of patients undergoing spine surgery, although
Discitis following surgery is a debilitating, but fortunately rare, the incidence of symptomatic deep venous thromboembolism is
complication.41 Incidental dural tears during surgery may result much lower. The use of chemoprophylaxis is still controversial
in postoperative cerebrospinal fluid leak and meningitis and may owing to the incidence of postoperative epidural hematoma which
result in symptomatic adhesive arachnoiditis. A rare, but often may cause neurologic deficits. Judicious use of mechanical pro-
irreversible complication is loss of vision owing to compression of phylaxis and early mobilization of patients at high risk may help
the orbits while the patient is positioned prone for lumbar spine to mitigate the incidence of symptomatic deep venous thrombo-
surgery.42 embolism. Low-molecular-weight heparin has also been used for
Neurologic injury may range from injury to the nerve roots the first week in some studies.45,46
to a complete cauda equina syndrome (0.38%).43 This syndrome Ekman et al.47 followed 111 patients who were randomized
could result owing to an injury from a misplaced screw (out of the to exercise, surgery without fusion, or surgery with spinal instru-
pedicle), neuropraxia from excessive manipulation during reduc- mentation for a mean of 12.6 years.47 They found that adjacent
tion of the spondylolisthesis, or even from direct injury to the segment disk disease was higher in patients with spinal instrumen-
neural structures. Postoperative epidural hematoma compressing tation, and that it was highest in patients who had laminectomy
on the cauda equina or conus medullaris also needs to be ruled and spinal stabilization. Semirigid or dynamic stabilization has
out, especially when the neurologic deficit is rapidly worsen- been attempted to reduce the incidence of this complication, but
ing in the acute postoperative period. In most cases, a finding the results are not yet convincing.48
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CHAPTER 1 General Indications and Contraindications 9
A B
C D
SELF–GUIDED INSERTION
E F
• Fig. 1.4 A and B. Vessel retraction during anterior retroperitoneal exposure at L5-S1 and L4-5 levels,
respectively. C. An oblique cage insertion at 25 degrees obviating vessel retraction and ligation-sectioning
of its branches. D. Use of inserter protecting the large vessels. E and F. Anchoring blades with directional
serrations to prevent graft back-outs, compared to conventional straight screws. (Figures C–F Courtesy
Zimmer Biomet, Warsaw, Indiana, USA.)
Techniques and Technologies in Lumbar TLIF using a “pedicle-based” lateral retractor system, providing
Interbody Fusion Surgery an extended lateral view of the disk space, causing lesser muscu-
lar and vascular interruption, and also preventing muscle creep
This textbook provides an overview of the novel technologies from intraoperative shifting of retractor assembly. This technique
and techniques involved in modern LIF surgeries. Fig. 1.4 clearly provides a better visualization of Kambin’s triangle during TLIF,
represents the vessel-mobilization strategies at various disk lev- providing wider lateral working space and hence safe and easy
els during an anterior lumbar interbody exposure and the new placement of interbody graft.
oblique-modification technique synergized with appropriate Neuronavigation and robotics have emerged as the latest addi-
nuances in technology. This is a perfect example of synergistic tions to the armamentarium. Fig. 1.6 illustrates intraoperative
improvisation in both anatomy-based technique and technology, navigation using interbody graft registration with intraoperative
which also accommodates the straight transpedicular screws eas- images using O-arm images transferred to a Stealth system. Both
ily. Likewise, Fig. 1.5 describes the mini-open modification of two-dimensional and three-dimensional image acquisitions are
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10 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
Pedicle Based
Lateral Retractor
• Fig. 1.5 Lateral retractor-distractor blade based on pedicle to expose the Kambin’s triangle. This lat-
eral retractor, along with a Gelpi self-retaining ratcheted finger-ring retractor, can facilitate extreme lateral
dissection by providing a fixed “extreme lateral” point preventing vascular disruption and muscle shifting
caused by migration of the retractor assembly. (Courtesy K2M, Inc., Leesburg, Virginia.)
• Fig. 1.6 O-arm technology for intraoperative spinal navigation and use in lumbar interbody fusion sur-
gery. Note the radiation dose curves around the surgical table. (Images Provided by Medtronic Inc. Incor-
porates technology developed by Gary K. Michelson, MD.)
possible with surgical personnel situated at least 15 feet away from Conclusions
the patient during image acquisition, minimizing the radiation
load for the surgeon and the operating room team. Similarly, there Although a century has passed since the first attempt at fusion
have been many recent FDA–approved devices in spinal robotics of the lumbar spine, the relative and absolute indications and
marketed for transpedicular access, including MedTech’s ROSA contraindications are still a matter of debate. Whereas there is
and Mazor X, a third-generation robotic system following the a broad consensus that patients with unstable spondylolisthesis
original Spine Assist in 2004 and Renaissance system in 2011. and symptomatic disease need surgical fixation, other scenarios
However, there is paucity of literature elucidating the efficacy and are not so clear-cut as in the presence of associated synovial cysts
superiority of using robotic technology in lumbar interbody graft at that level suggesting mobility. Most surgeons would agree that
insertion. the following patients would merit surgery for spinal stabilization:
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CHAPTER 1 General Indications and Contraindications 11
spondylolisthesis with failed medical management, traumatic and 18. Herkowitz HN. Degenerative lumbar spondylolisthesis: evolution
neoplastic conditions, postlaminectomy instability, and chronic of surgical management. Spine J. 2009;9:605–606.
pain owing to discitis or osteomyelitis. The role of surgical fusion 19. Kepler CK, Vaccaro AR, Hilibrand AS, et al. National trends in
in patients with idiopathic chronic back pain remains controver- the use of fusion techniques to treat degenerative spondylolisthesis.
Spine (Phila Pa 1976). 2014;39:1584–1589.
sial, and more studies are required to elucidate the best treatment
20. Bridwell KH, Sedgewick TA, O’Brien MF, et al. The role of fusion
options for these patients. Technologic improvements will lead and instrumentation in the treatment of degenerative spondylolis-
the way into the future, with better implants, safer osteogenetic thesis with spinal stenosis. J Spinal Disord. 1993;6:461–472.
materials, and a concerted move toward minimally invasive sur- 21. Bae HW, Rajaee SS, Kanim LE. Nationwide trends in the surgical
gery with fewer morbidities and reduced hospital stay. management of lumbar spinal stenosis. Spine. 2013;38:916–926.
22. Försth P, Ólafsson G, Carlsson T, et al. A randomized, controlled trial
of fusion surgery for lumbar spinal stenosis. N Engl J Med. 2016;
References 374:1413–1423.
23. Ghogawala Z, Dziura J, Butler WE, et al. Laminectomy plus fusion
1. Hadra BE. The classic: wiring of the vertebrae as a means of immobi- versus laminectomy alone for lumbar spondylolisthesis. N Engl J
lization in fracture and Potts disease. Berthold E Hadra. Clin Orthop. Med. 2016;374:1424–1434.
1975;112:4–8. 24. Peul WC, Moojen WA. Fusion for lumbar spinal stenosis—safe-
2. Hibbs RA. An operation for progressive spinal deformities. N Y guard or superfluous surgical implant? Editorial. N Engl J Med.
Med. 1911;121:1013. 2016;374:1478–1479.
3. Albee FH. Transplantation of a portion of the tibia into the spine 25. Jones TR, Rao RD. Adult isthmic spondylolisthesis. J Am Acad
for Pott’s disease. JAMA. 1911;57:855. Orthop Surg. 2009;17:609–617.
4. Watkins MB. Posterolateral fusion of the lumbar and lumbosacral 26. Moller H, Hedlund R. Surgery versus conservative management in
spine. J Bone Joint Surg Am. 1953;35:1014–1018. adult isthmic spondylolisthesis. Spine. 2000;25:1711–1715.
5. Harrington PR. Treatment of scoliosis. Correction and internal fixation 27. Bendo JA, Spivak J, Moskovich R, et al. Instrumented posterior
by spine instrumentation. J Bone Joint Surg Am. 1962;44:591–610. arthrodesis of the lumbar spine in patients with diabetes mellitus.
6. Burkus JK, Gornet MF, Dickman CA, Zdeblick TA. Anterior lum- Am J Orthop. 2000;29:617–620.
bar interbody fusion using rhBMP-2 with tapered interbody cages. 28. Glassman SD, Alegre G, Carreon L, et al. Perioperative complica-
J Spinal Disord Tech. 2002;15(5):337–349. tions of lumbar instrumentation and fusion in patients with diabe-
7. Carragee EJ, Hurwitz EL, Weiner BK. A critical review of recom- tes mellitus. Spine J. 2003;3(6):496–501.
binant human bone morphogenetic protein-2 trials in spinal 29. Guzman JZ, Iatridis JC, Skovrlj B, et al. Outcomes and compli-
surgery: emerging safety concerns and lessons learned. Spine J. cations of diabetes mellitus on patients undergoing degenerative
2011;11(6):471–491. lumbar spine surgery. Spine. 2014;39(19):1596–1604. https://doi.
8. Hansen SM, Sasso RC. Resorptive response of rhBMP2 simulating org/10.1097/BRS.0000000000000482.
infection in an anterior lumbar interbody fusion with a femoral 30. Lee TC, Ueng SW, Chen HH, et al. The effect of acute smoking
ring. J Spinal Disord Tech. 2006;19(2):130–134. on spinal fusion: an experimental study among rabbits. J Trauma.
9. Vaidya R, Weir R, Sethi A, et al. Interbody fusion with allograft and 2005;59:402–408.
rhBMP-2 leads to consistent fusion but early subsidence. J Bone 31. Andersen T, Christensen FB, Laursen M, et al. Smoking as a
Joint Surg Br. 2007;89(3):342–345. predictor of negative outcome in lumbar spinal fusion. Spine.
10. Hustedt JW, Blizzard DJ. The controversy surrounding bone mor- 2001;26:2623–2628.
phogenetic proteins in the spine: a review of current research. Yale J 32. Crawford CH, Carreon LY, Djurasovic M, et al. Lumbar fusion
Biol Med. 2014;87(4):549–561. outcomes in patients with rheumatoid arthritis. Eur Spine J.
11a. Rihn JA, Patel R, Makda J, et al. Complications associated with 2008;17:822–825.
single-level transforaminal lumbar interbody fusion. Spine J. 33. Kanis JA, Burlet N, Cooper C, et al. European guidance for the
2009;9(8):623–629. diagnosis and management of osteoporosis in postmenopausal
11b. Mclain RF, Fleming JE, Boehm CA, et al. Aspiration of osteopro- women. Osteoporos Int. 2008;19:399–428.
genitor cells for augmenting spinal fusion: comparison of progeni- 34. Xue Q, Li H, Zou X, et al. The influence of alendronate treatment
tor cell concentrations from the vertebral body and iliac crest. J Bone and bone graft volume on posterior-lateral spine fusion in a porcine
Joint Surg Am. 2005;87(12):2655–2661. https://Doi:10.2106/ model. Spine. 2005;30:1116–1121.
jbjs.e.00230. 35. Eccher MA, Ghogawala Z, Steinmetz MP. The possibility of clini-
12. Leu HF, Hauser RK. Percutaneous endoscopic lumbar spine fusion. cal trials in neurophysiologic intraoperative monitoring: a review. J
Neurosurg Clin North Am. 1996;7:107–117. Clin Neurophysiol. 2014;31:106–111.
13. Kambin P. Diagnostic and therapeutic spinal arthroscopy. Neuro- 36. Ney JP, van der Goes DN, Watanabe JH. Cost-benefit analysis:
surg Clin North Am. 1996;7:65–76. intraoperative neurophysiological monitoring in spinal surgeries. J
14. Jacquot F, Gastambide D. Percutaneous endoscopic transfo- Clin Neurophysiol. 2013;30:280–286.
raminal lumbar interbody fusion: is it worth it? Int Orthop. 37a. Fehlings MG, Brodke DS, Norvell DC, et al. The evidence for
2013;37(8):1507–1510. intraoperative neurophysiological monitoring in spine surgery: does
15. Newman PH, Stone KH. The etiology of spondylolisthesis. J Bone it make a difference? Spine (Phila Pa 1976). 2010;35:S37–S46.
Joint Surg Br. 1963;45:39–59. 37b. Hadley MN, Shank CD, Rozzelle CJ, Walters BC. Guidelines for
16. Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical compared the use of electrophysiological monitoring for surgery of the human
with nonoperative treatment for lumbar degenerative spondylolis- spinal column and spinal cord. Neurosurgery. 2017;81(5):713–732.
thesis. Four-year results in the Spine Patient Outcomes Research https://doi.org/10.1093/neuros/nyx466.
Trial (SPORT) randomized and observational cohorts. J Bone Joint 38. Kalanithi PS, Patil CG, Boakye M. National complication rates and
Surg Am. 2009;91(6):1295–1304. disposition after posterior lumbar fusion for acquired spondylolis-
17. Watters WC, Bono CM, Gilbert TJ, et al. An evidence-based clini- thesis. Spine. 2009;34:1963–1969.
cal guideline for the diagnosis and treatment of degenerative lum- 39. Juratli SM, Franklin GM, Mirza SK, et al. Lumbar fusion outcomes in
bar spondylolisthesis. Spine J. 2009;9:609–614. Washington State workers’ compensation. Spine. 2006;31:2715–2723.
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40. Olsen MA, Mayfield J, Lauryssen C, et al. Risk factors for surgical 45. Glotzbecker MP, Bono CM, Wood KB, et al. Thromboembolic dis-
site infection in spinal surgery. J Neurosurg Spine. 2003;2:149–155. ease in spinal surgery: a systematic review. Spine (Phila Pa 1976).
41. Chaudhary SB, Vives MJ, Basra SK, et al. Postoperative spinal 2009;34(3):291–303.
wound infections and postprocedural diskitis. J Spinal Cord Med. 46. Yang SD, et al. Prevalence and risk factors of deep vein thrombosis
2007;30(5):441–451. in patients after spine surgery: a retrospective case-cohort study. Sci
42. Nickels TJ, Manlapaz MR, Farag E. Perioperative visual loss after Rep. 2015;5:11834.
spine surgery. World J Orthop. 2014;5(2):100–106. 47. Ekman P, Moller H, Shalabi A, et al. A prospective randomized
43. Cook C, Santos GC, Lima R, et al. Geographic variation in lumbar study on the long-term effect of lumbar fusion on adjacent disc
fusion for degenerative disorders: 1990 to 2000. Spine J. 2007;7: degeneration. Eur Spine J. 2009;18:1175–1186.
552–557. 48. Cakir B, Carazzo C, Schmidt R, et al. Adjacent segment mobil-
44. Ogilvie JW. Complications in spondylolisthesis surgery. Spine. ity after rigid and Semirigid instrumentation of the lumbar spine.
2005;30:S97–S101. Spine. 2009;34:1287–1291.
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2
Complications and Avoidance in
Lumbar Interbody Fusions
VINCENT J. ALENTADO AND MICHAEL P. STEINMETZ
Introduction placed on the thecal sac and nerve roots in order to gain access to
the intervertebral space.1 Furthermore, PLIF requires violation of
As with any surgical procedure, interbody fusions are associated both facet joints to enable adequate exposure for graft placement.
with unique complications. Given the wide variety of approaches
utilized when performing an interbody fusion, it is important to Nerve Root Injury
recognize common complications associated with each specific
technique. Recognition of these complications allows the surgeon Arguably the worst complication that commonly occurs with
to utilize a more protective surgical approach to limit periopera- the PLIF procedure is nerve root injury. The current literature is
tive complications. Furthermore, recognition of common compli- widely variable in reported rates of nerve root injury with inci-
cations better enables the surgeon to inform patients of the risks dences ranging from 0.6% to 24%.2–5 Davne and Myers5 reported
of potential surgical treatment. the lowest rate of nerve root injury at only a 0.6% in their series
All pressure points should be padded to avoid peroneal of 384 PLIF procedures.
neuropathy with pressure on the lateral leg at the proximal Given the high rates and significant morbidity associated with
fibula. Care must also be made when positioning the patient nerve root injury during PLIF, many authors have investigated
in the lateral position. The authors do not advocate aggres- techniques to lower the rates of this complication. Barnes and
sive “breaking” of the table when lateral interbody fusion is colleagues2 reported a 14% incidence of permanent nerve root
performed. This aggressive “breaking” or bending the bed with injury when using threaded fusion cages compared to a 0% inci-
the bed and foot of the bed lowered while the fulcrum at the dence using smaller allograft wedges in their retrospective review
lumbar spine is raised directly or indirectly has resulted in of 49 patients. The authors noted their preference for allograft
opening of the space between the iliac crest and rib cage. This wedges given these findings and their discovery that clinical out-
was performed at the expense of potential stretching of the comes were better in the allograft wedge group. Krishna and col-
lumbar plexus and resultant neuropathy (i.e., ipsilateral thigh leagues6 noted a 9.7% rate of postoperative neuralgia in patients
pain and/or weakness). treated with subtotal facetectomy compared with a 4.9% rate in
At times intraoperative neuromonitoring is utilized in an 226 patients treated with total facetectomy. Although this was not
attempt to minimize neurological complications following inter- statistically significant, the authors noted their preferred practice
body fusion. No high level evidence suggests the usage of these of total facetectomy to help prevent nerve root injury. In a separate
techniques results in improved outcome or decreased complica- study, Okuda et al.7 found a 6.8% rate of postoperative neuralgia
tions. Triggered electromyography (EMG) is commonly used with total facetectomy during PLIF.
during transpsoas direct lateral interbody fusion. Identification of The aforementioned studies demonstrate the importance of
motor nerves may decrease the incidence of weakness following a wide exposure with adequate facetectomy, careful dissection
surgery; however, it should be noted that this technique cannot techniques without unnecessary traction of nerve root (especially
accurately identify sensory nerves. with canal stenosis at the levels above), and avoidance of oversized
grafts in order to minimize the risk of nerve root injury during
Posterior Lumbar Interbody Fusion PLIF. Angled nerve root retractors and direct visualization of the
nerve roots at all times can also help prevent neurologic injury
Posterior lumbar interbody fusion (PLIF) is a technically challeng- during the procedure. A more aggressive total facetectomy can
ing procedure and therefore is associated with increased complica- provide an excellent window for graft placement while minimiz-
tion rates compared with other lumbar fusion techniques. Two ing the amount of retraction on the nerve root. Triggered EMG,
of the primary complications of PLIF are nerve root injury and if utilized, may enable assessment of undue retraction during this
incidental durotomy. The reason for higher rates of these specific step of the operation; however, data do not support an improved
complications is owing to the significant traction that must be outcome.
13
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14 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
A B
• Fig. 2.1 Migration of the interbody cage. Axial (A) and sagittal (B)
computed tomography (CT) scan of the lumbar spine showing posterior
migration of an interbody cage (the first approach), which has resulted in
neural compression. (From Benzel E. Spine Surgery: Techniques, Compli-
cation Avoidance, & Management. 3rd ed Philadelphia: Elsevier Saunders;
2012:539.)
Durotomy
Incidental durotomies are another common complication that
occurs at higher rates during PLIF procedures owing to the direct
retraction of the thecal sac intraoperatively. Studies have reported
rates of durotomies at 9% to 19%, with higher rates occurring dur-
ing reoperation surgeries owing to dural adhesions.3,7,8 If a durot-
omy does occur, it can usually be repaired primarily. However, repair
may be more difficult when using a minimally invasive technique.
• Fig. 2.2 Steerable cage placed along the anterior annulus. Newer
Graft- and Cage-Related Complications cage design allows cage placement as anterior as possible. Cages can
Graft dislodgement and loosening are other complications asso- now be steered and placed along the anterior annulus.
ciated with PLIF, especially during early use of the technique
(Fig. 2.1). The cumulative incidence of graft-related complications utilized to prevent this development. Lastly, there is a risk of loss
is less than 5%.9 However, the rate of this complication is even of lumbar lordosis. This was much more relevant with the use of
lower when posterior pedicle screw stabilization is used with the older cages; however, careful attention to detail should minimize
PLIF procedure. Conversely, total facetectomy is associated with a this complication.
higher incidence of graft extrusion owing to the decreased stability
associated with this technique, but is lessened with the use of screw Anterior Lumbar Interbody Fusion
fixation. When graft-related complications are symptomatic, they
require revision surgery, which is technically challenging. In contrast to PLIF, the anterior lumbar interbody fusion (ALIF)
Interbody cage type and positioning have been shown to effect technique can provide the same interbody support without
rates of migration, with newer technologies being utilized to manipulation of the dural or posterior neural structures. However,
decrease the incidence of graft dislodgement (Fig. 2.2).10 Further- the ventral approach required during the ALIF procedure often
more, subsidence of the implants may also occur after PLIF, which necessitates significant retraction of the iliac vessels, hypogastric
may result in postoperative neuralgia (Fig. 2.3).6 nerves, and peritoneum, which may result in direct injury to these
structures. Other complications associated with ALIF include an
increased risk of deep vein thrombosis (DVT), abdominal wall
Nonunion hernias, and retrograde ejaculation in men.13
Fusion rates after PLIF are generally high, with studies reporting
incidences of 95% to 98%.7,8,11 However, there is some reported Vascular Injury
variability with Rivet et al.12 achieving a fusion rate of only 74%
in 42 patients receiving PLIF. Major blood vessel injuries are rare during ALIF. However, vas-
cular injury to the common iliac vessels occurs at a rate of 1%
to 7%, with higher rates occurring during exposure of the L5-S1
Other Complications level.14–16 The common iliac vein is very compressible; it lies pos-
Other complications, including epidural hematoma (1%),3 wound terior to the artery such that it can easily be mistaken for soft tis-
infections, and other nonimplant-related complications, seem to sues during exposure. The iliolumbar vein is at higher risk during
occur with a similar frequency in PLIF as in other reconstructive exposure of the L4-5 level. Some surgeons advocate for controlled
spinal operations. Although adjacent segment disease (ASD) is ligation of this vessel in all exposures to minimize the risk of inad-
more of an adverse outcome than complication, some studies have vertent tearing with retraction.15,17 To avoid injury of these ves-
demonstrated earlier rates of ASD and revision surgery compared sels, self-retaining retractors should not be used on these vessels
with other cohorts. However, new surgical techniques have been during exposure.
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CHAPTER 2 Complications and Avoidance in Lumbar Interbody Fusions 15
A B
• Fig. 2.3 Subsidence of the interbody cage. A. This patient underwent a two-level interbody fusion,
L3-4 and L4-5. B. One month after index surgery, the patient developed severe back and leg pain. Lateral
radiograph demonstrates subsidence of the L4-5 interbody graft and instability.
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16 SE C T I O N 1 Lumbar Interbody Fusions – A Primer
Graft Dislodgement
Graft dislodgement is an infrequent complication following TLIF
(see Fig. 2.1). Anecdotal reports suggest cage migration after TLIF
may not cause neural compression, or necessitate revision surgery,
as often as after PLIF.30
NonUnion
Achievement of fusion at 1 year after TLIF ranges from 80% to
98%, with lower fusion rates seen in multilevel fusions.31,32
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CHAPTER 2 Complications and Avoidance in Lumbar Interbody Fusions 17
complications seen with the XLIF technique are transient groin For all interbody fusions, care must be taken in patients with
and thigh paresthesias secondary to injury of the genitofemoral advanced osteoporosis. In fact, interbody fusion with a structural graft
nerve. should be avoided in such circumstances in the authors’ opinion. The
rate of subsidence, construct failure, and nonunion are greater than
Neurologic Complications the benefits of this surgical technique (authors’ opinion). Surgery
may be indicated for discitis, which fails to be effectively treated with
The reported incidence of paresthesias after XLIF is extremely antibiotics. In this situation, diskectomy may be required to effec-
variable with incidences ranging from 0.7% to 62.7%.34–37 These tively debride the disk space. A structural interbody graft should be
paresthesias are usually located in the groin and thigh owing to not placed in this situation, especially polyetheretherketone (PEEK),
injury of the genitofemoral nerve. In most cases, the paresthesias but rather autograft packed in the disk space.
improve within 4 to 12 weeks postoperatively, with more than
90% recovering by 1 year.34–37 In addition to paresthesias, tran- Conclusion
sient psoas or quadriceps weakness occurs at a rate of 1% to 24%
after XLIF.35,37,38 Interbody fusion is effective for successful treatment of a number
Cummock et al.35 noted a higher rate of thigh pain, numbness, of lumbar pathologies. It has been shown to result in improved
and weakness after L4-5 surgery in their review of 59 patients fusion rates and segmental alignment. A number of complications
receiving XLIF. However, this was not a statistically significant dif- may be seen following each specific interbody technique. These
ference, possibly owing to low sample size. Because of the poten- complications may be mitigated by careful patient selection and
tial for higher neurologic complication rates at this level, Rodgers careful attention to detail.
and colleagues38 opted to give patients 10 mg of IV dexametha-
sone intraoperatively during L4-5 XLIF procedures. The authors References
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during XLIF of the L4-5 level. fusion techniques: transforaminal lumbar interbody fusion (TLIF)
The natural history of these injuries is favorable. Most cases or posterior lumbar interbody fusion (PLIF) approaches. Curr Rev
of weakness, numbness, or paresthesias are usually resolved by six Musculoskelet Med. 2009;2(2):118–126. https://doi.org/10.1007/
s12178-009-9053-8.
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2. Barnes B, Rodts GE, Haid RW, et al. Allograft implants for posterior
To avoid neurologic injury after XLIF, it is imperative to lumbar interbody fusion: results comparing cylindrical dowels and
perform careful dissection, avoid tension on the muscle, and impacted wedges. Neurosurgery. 2002;51(5):1191–1198. discussion
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tion should not be greater than the minimum required for 3. Hosono N, Namekata M, Makino T, et al. Perioperative compli-
diskectomy. Neurologic monitoring may also decrease the risk cations of primary posterior lumbar interbody fusion for nonisth-
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body fusion. Spine. 1988;13(3):366–369. thesis. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc
26. Harms J, Rolinger H. A one-stager procedure in operative treatment Eur Sect Cerv Spine Res Soc. 2015;24(suppl 3):314–321. https://doi.
of spondylolistheses: dorsal traction-reposition and anterior fusion org/10.1007/s00586-015-3841-1.
(author’s transl). Z Für Orthop Ihre Grenzgeb. 1982;120(3):343–347. 38. Rodgers WB, Gerber EJ, Patterson J. Intraoperative and early post-
https://doi.org/10.1055/s-2008-1051624. operative complications in extreme lateral interbody fusion: an anal-
27. Villavicencio AT, Burneikiene S, Bulsara KR, et al. Perioperative ysis of 600 cases. Spine. 2011;36(1):26–32. https://doi.org/10.1097/
complications in transforaminal lumbar interbody fusion versus BRS.0b013e3181e1040a.
anterior-posterior reconstruction for lumbar disc degeneration and
instability. J Spinal Disord Tech. 2006;19(2):92–97. https://doi.
org/10.1097/01.bsd.0000185277.14484.4e.
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S E C T I ON 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
3
Relevant Surgical Anatomy of the
Dorsal Lumbar Spine
AL EX M. WITEK, ADAM KHALIL, AND AJIT A. KRISHNANEY
Introduction to L5 (14 mm).3 With the exception of L5, which has especially
wide pedicles, the lumbar pedicles are taller than they are wide,
The typical lumbar spine consists of five vertebrae that are con- and it is therefore the transverse width of the pedicle that limits
nected in series and permit motion between each segment. its instrumentation.
Each lumbar vertebra is an anatomically complex structure that The pedicle is connected to the dorsal vertebral elements at
consists of multiple distinct subunits. Adjacent vertebrae are the junction of the superior articulating process (SAP) and the
connected through the disk space anteriorly and the paired zyg- pars interarticularis (“pars”). The pars connects the SAP and ped-
apophyseal (facet) joints posteriorly. Further stability is provided icle to the lamina and the inferior articulating process (IAP). The
by a variety of supporting ligaments. The lumbar spinal canal lamina is a sheet-like subunit that forms the dorsal roof of the
houses the conus medullaris rostrally, along with the emerging spinal canal. In the sagittal plane, it slopes posteriorly from supe-
cauda equina, with each lumbar nerve root extending caudally rior to inferior; in the axial plane, it is angled posteriorly from
and exiting the canal through its neural foramen directly below lateral to medial, with an apex at the midline. When viewed in
the same-numbered pedicle. Understanding the anatomic rela- the coronal plane, the lamina is tall and narrow at the superior
tionships between these neural structures and the neighboring lumbar levels and becomes shorter and wider as it goes down to
vertebral bone, disk, and ligament is key to performing effective the lower lumbar levels. Between the SAP and IAP, the lamina is
and safe posterior interbody fusion. contiguous with the pars interarticularis, which forms the nar-
Illustrated views of a lumbar vertebra are provided in Figs. 3.1 rowest point along the lateral edge of the dorsal vertebra. The
and 3.2. The most ventral part of each vertebra is the vertebral body, spinous process is oriented in the midline sagittal plane and proj-
a cylindrically shaped unit that serves to support axial loads. The ects dorsally from the lamina with downward angulation, lying
vertebral bodies become progressively larger in a cranial –o-caudal slightly below its corresponding vertebral body and overlying the
direction. In the lumbar spine, where the bodies are largest, the subjacent interlaminar space. The spinous process is the most
average vertebral body height is 27 mm and is similar among all dorsal part of the vertebra and the first bone encountered during
lumbar levels. In the axial plane, the anterior-posterior length is posterior midline surgical exposure. The paired transverse pro-
greater than the transverse width, and the bodies are longer and cesses originate from the junction of the pedicle with the SAP
wider at either endplate than at their cranial-caudal midpoint. The and project laterally.
transverse width and mid-sagittal length of the vertebral bodies The zygapophyseal (facet) joints are paired synovial joints
increase progressively from L1 (29 mm wide and 40 mm long at the that allow for articulation of the posterior portion of the ver-
cranial-caudal midpoint) to L5 (32 mm wide and 46 mm long).1 tebrae. Each facet joint consists of the IAP from the rostral ver-
The endplate is composed of cortical bone and is slightly concave. tebra (e.g., L4) and the SAP of the caudal vertebra (e.g., L5).
Its central portion is thinnest and porous, whereas the outer portion Each of the apposed articular surfaces consists of smooth cortical
(the apophyseal ring) is thicker and stronger.2 bone covered with a layer of hyaline cartilage. The joint space
The pedicles are oriented primarily in an anterior-to-posterior contains synovial fluid and is enclosed posteriorly by a fibrous
direction and connect the vertebral body to the dorsal elements. capsule.4 The facet joints in the lumbar spine are angled anteri-
Each pedicle is angled medially in the axial plane from posterior orly (i.e., anterior-superior to posterior-inferior) in the sagittal
to anterior, and this angle increases progressively from L1 (average plane, and medially (i.e., posterior-lateral to anterior-medial) in
medial angulation of 11 degrees) to L5 (30 degrees). The trans- the axial plane. This orientation allows significant flexion/exten-
verse pedicle width also increases progressively from L1 (8.7 mm sion and moderate lateral bending, but minimal axial rotation.5,6
average width) to L5 (18 mm). The sagittal pedicle height displays The facet joint angle in the axial plane (with respect to midline)
an opposite relationship, decreasing slightly from L1 (15.4 mm) decreases progressively at each level from rostral to caudal, such
19
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20 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
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CHAPTER 3 Relevant Surgical Anatomy of the Dorsal Lumbar Spine 21
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22 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
R’ R
Left
P’ P
D
Caudal Cranial
SP
Right IAP
A SAP’
PI
F
F F • Fig. 3.5 Posterior view of the dorsal lumbar spine (SP, spinous process;
L, lamina; SAP′, superior articulating process of the subjacent vertebra; PI,
pars interarticularis; IAP, inferior articulating process). The IAP and SAP′
L combine to form the facet joint (F). The dashed lines toward the left of the
spine represent the projections of deeper structures, including the same-
LF
numbered pedicle (P), exiting nerve root (R), intervertebral disk (D), subja-
cent pedicle (P′), and traversing nerve root (R′).
SP
B
• Fig. 3.4 A. Surgeon’s view of the dorsal spinal elements following a R’
midline incision and subperiosteal elevation of the paraspinal muscles. The
directions (left, right, cranial, caudal) have been labeled for orientation. B.
The spinal elements of the index level have been outlined and labeled for
easier visualization. The spinous process (SP) lies in the midline. The lamina TS
(L) slopes downward where it meets the pars interarticularis (arrow) and the
facet joint capsules (F). Ligamentum flavum (LF) separates the lamina of this
level from that of the vertebra above.
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CHAPTER 3 Relevant Surgical Anatomy of the Dorsal Lumbar Spine 23
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24 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
A B
C D
• Fig. 3.8 Illustration of isthmic spondylolisthesis. Posterior (A) and lateral (B) views demonstrate that the superior facet joint is shifted ventrally and
inferiorly with respect to the inferior facet joint, and the defective pars interarticularis is elongated. A normal facet joint is shown for comparison, with (C)
posterior and (D) lateral views demonstrating the normal relationship of the facet joints to the pars interarticularis (arrow).
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CHAPTER 3 Relevant Surgical Anatomy of the Dorsal Lumbar Spine 25
References 12. Buckwalter JA. Aging and degeneration of the human intervertebral
disc. Spine (Phila Pa 1976). 1995;20(11):1307–1314.
1. Berry JL, Moran JM, Berg WS, et al. A morphometric study of 13. Koeller W, Meier W, Hartmann F. Biomechanical properties of
human lumbar and selected thoracic vertebrae. Spine (Phila Pa human intervertebral discs subjected to axial dynamic compression.
1976). 1987;12(4):362–367. A comparison of lumbar and thoracic discs. Spine (Phila Pa 1976).
2. Grant JP, Oxland TR, Dvorak MF. Mapping the structural prop- 1984;9(7):725–733.
erties of the lumbosacral vertebral endplates. Spine (Phila Pa 14. Yu S, Haughton VM, Sether LA, et al. Criteria for classify-
1976). 2001;26(8):889–896. https://doi.org/10.1097/00007632- ing normal and degenerated lumbar intervertebral disks.
200104150-00012. Radiology. 1989;170(2):523–526. https://doi.org/10.1148/radiol-
3. Zindrick MR, Wiltse LL, Doornik A, et al. Analysis of the mor- ogy.170.2.2911680.
phometric characteristics of the thoracic and lumbar pedicles. Spine 15. Finnan R, Archdeacon M. Applied anatomy of the sacral spine. In:
(Phila Pa 1976). 1987;12(2):160–166. Steinmetz MP, Benzel EC, eds. Benzel’s Spine Surgery: Techniques,
4. Taylor JR, Twomey LT. Age changes in lumbar zygapophyseal Complication Avoidance, and Management. 4th ed. Philadelphia:
joints. Observations on structure and function. Spine (Phila Pa Elsevier; 2017:114–118. https://doi.org/10.1016/B978-0-323-
1976). 1986;11(7):739–745. https://doi.org/10.1097/00007632- 40030-5.00010-1.
198609000-00014. 16. Başaloğlu H, Turgut M, Taşer FA, et al. Morphometry of the sacrum
5. White AA, Panjabi MM. The basic kinematics of the human spine. for clinical use. Surg Radiol Anat. 2005;27(6):467–471. https://doi.
A review of past and current knowledge. Spine (Phila Pa 1976). org/10.1007/s00276-005-0036-1.
1978;3(1):12–20. https://doi.org/10.1097/00007632-197803000- 17. Lehman RA, Kuklo TR, Belmont PJ, et al. Advantage of pedicle
00003. screw fixation directed into the apex of the sacral promontory
6. Ahmed AM, Duncan NA, Burke DL. The effect of facet geom- over bicortical fixation: a biomechanical analysis. Spine (Phila Pa
etry on the axial torque-rotation response of lumbar motion seg- 1976). 2002;27(8):806–811. https://doi.org/10.1097/00007632-
ments. Spine (Phila Pa 1976). 1990;15(5):391–401. https://doi. 200204150-00006.
org/10.1097/00007632-199005000-00010. 18. Wilson DA, Prince JR. John Caffey award. MR imaging determi-
7. Panjabi MM, White AA. Basic biomechanics of the spine. Neurosurgery. nation of the location of the normal conus medullaris throughout
1980;7(1):76–93. https://doi.org/10.1016/0268-0890(89)90038-8. childhood. AJR Am J Roentgenol. 1989;152(5):1029–1032. https://
8. Van Schaik JP, Verbiest H, Van Schaik FD. The orientation of lami- doi.org/10.2214/ajr.152.5.1029.
nae and facet joints in the lower lumbar spine. Spine (Phila Pa 1976). 19. Arslan M, Cömert A, Açar Hİ, et al. Neurovascular structures adja-
1985;10(1):59-63. cent to the lumbar intervertebral discs: an anatomical study of their
9. Benzel EC. Biomechanically relevant anatomy and material proper- morphometry and relationships. J Neurosurg Spine. 2011;14(5):630–
ties of the spine and associated elements. In: Biomechanics of Spine 638. https://doi.org/10.3171/2010.11.SPINE09149.
Stabilization. 2nd ed. New York: Thieme; 2001:1–18. 20. Kadish LJ, Simmons EH. Anomalies of the lumbosacral nerve roots.
10. Lollis SS. Applied anatomy of the thoracic and lumbar spine. In: An anatomical investigation and myelographic study. J Bone Joint
Steinmetz MP, Benzel EC, eds. Benzel’s Spine Surgery: Techniques, Surg Br. 1984;66(3):411–416.
Complication Avoidance, and Management. 4th ed. Philadelphia: 21. Merks JHM, Smets AM, Van Rijn RR, et al. Prevalence of rib anom-
Elsevier; 2017:95–113. https://doi.org/10.1016/B978-0-323- alies in normal Caucasian children and childhood cancer patients.
40030-5.00009-5. Eur J Med Genet. 2005;48(2):113–129. https://doi.org/10.1016/j.
11. Liu JKC. Intervertebral disc: anatomy, physiology, and aging. In: ejmg.2005.01.029.
Steinmetz MP, Benzel EC, eds. Benzel’s Spine Surgery: Techniques, 22. Tang M, Yang X, Yang S, et al. Lumbosacral transitional vertebra in a
Complication Avoidance, and Management. 4th ed. Philadelphia: Else- population-based study of 5860 individuals: prevalence and relation-
vier; 2017:119–123. https://doi.org/10.1016/B978-0-323-40030- ship to low back pain. Eur J Radiol. 2014;83(9):1679–1682. https://
5.00011-3. doi.org/10.1016/j.ejrad.2014.05.036.
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4
Relevant Surgical Anatomy of the
Lateral and Anterior Lumbar Spine
ANGELA M. RICHARDON, GLEN MANZANO, AND ALLAN D. LEVI
27
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28 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
1
1 1
2 Atlas 2
2
Cervical 3 Axis 3
3
vertebrae 4 4 4
5 5 5
6 6 6
7 7 7
1 T1 1
2 2
3
3 4
4
5
5
6
Thoracic 6
vertebrae 7 7
8 8
9 9
10 10
11 11
12
12
1
1 1
2
2
2
Lumbar
3 3
vertebrae 3
4 4 4
5 5 5
Sacrum
Coccyx
• Fig. 4.1Coronal and sagittal views of the bony anatomy of the spine. (From Benzel E. Spine Surgery: Tech-
niques, Complication Avoidance, & Management, 3rd ed. Philadelphia: Elsevier Saunders; 2012: Figure 32-1.)
Vertebral
foramen
Body
Superior articular
process
Spinous process B
Lamina
Pedicle
Pedicle
Transverse Body Transverse process
process
A Superior articular
process
Spinous process
Inferior articular
process
D Inferior vertebral
notch
• Fig. 4.2 Lumbar vertebral bodies from superior (A), anterior (B), midsagittal (C), and lateral (D) views. (From
Benzel E. Spine Surgery: Techniques, Complication Avoidance, & Management, 3rd ed. Philadelphia:
Elsevier Saunders; 2012: Figure 36-2.)
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CHAPTER 4 Relevant Surgical Anatomy of the Lateral and Anterior Lumbar Spine 29
Pyramidalis
muscle
Rectus abdominis
Psoas minor muscle
muscle
Transverse abdominal muscle
Psoas major muscle Internal oblique abdominal muscle
Thoracolumbar
fascia
Latissimus
dorsi muscle
Multifidus muscle Iliocostalis lumborum muscle
• Fig. 4.3 Muscular anatomy of relevance for lateral and anterior approaches – (A) the psoas muscles
extending from the spine and passing under the inguinal ligament to insert on the femur. (B) Axial section
showing mediolateral orientation of erector spinae and psoas muscles. (From Benzel E. Spine Surgery:
Techniques, Complication Avoidance, & Management, 3rd ed. Philadelphia: Elsevier Saunders; 2012:
Figures 36-6 and 36-7b.)
Access to the L5-S1 disk space is through a working corridor lie in close proximity to the center of the disk space at L5-S1 and
developed between the common iliac arteries and veins after sac- are thus at risk for injury in the anterior approach to this level.7
rificing the median sacral artery. At L4-5, a left-sided approach is Anatomic variations in the relative positions of the aorta and the
usually preferred, which involves retraction of the aorta to gain IVC have been described (Fig. 4.5). The aorta typically lies ventral
access to the mid-line disk space. to the IVC and slightly to the left. Owing to this variation in the
The aorta descends along the ventromedial spine only 2.1 cm from course of the aorta, IVC, their relative positions, and the location
the center of the intervertebral disk.5 This large vessel begins at the of the bifurcation, many authors advocate preoperative imaging to
fourth thoracic vertebra and continues to the fourth lumbar vertebra thoroughly define the vascular anatomy of each patient.
where it divides into the two common iliac arteries. The common iliac
veins join ventral to the fifth lumbar vertebra forming the IVC. This Arterial Supply to the Spine
vessel parallels the path of the aorta traveling along the right anterior
aspect of the lumbar vertebrae, with a mean of 1.4 cm between the Lumbar arteries are direct branches of the aorta that run across the
vessel and the center of the intervertebral disk.5 The IVC migrates vertebral body, approximately 4 mm on average, below the infe-
posteriorly and laterally with caudal progression from L1 to L5. The rior endplate of the superior intervertebral disk space (Fig. 4.6).5
iliolumbar vein crosses from the IVC at the level of the L5 vertebral These vessels originate near the midpoint of the vertebral body
body crossing the psoas muscle. In approaches that require dissection and pass under the sympathetic chain and onto the muscles of the
at L4-5, this vein is usually ligated and divided to the left of the left abdominal wall forming numerous anastomoses with each other
common iliac vein (Fig. 4.4). and lower posterior intercostal, subcostal, iliolumbar, deep cir-
Analysis of the location of the IVC in magnetic resonance cumflex iliac, and inferior epigastric arteries. The spinal branches
images of 48 individuals demonstrated that in 70% the position pierce the dura in the vicinity of the dorsal root ganglia and are
of this vessel at the L4-5 disk level would place it at risk during named according to their termination: radicular if the vessel ter-
a right-sided lateral approach.6 Additionally, the right common minates along the root, radiculopial if it anastomosis with the
iliac vein can lie draped across the anterolateral corner of the disk pial vessels of the spinal cord, radiculomedullary if it anastomoses
space, precluding safe entry at this point.5 During anterior lumbar with the anterior spinal artery. The artery of Adamkiewicz is the
interbody fusion, the disk space associated with the highest risk largest radiculomedullary artery and may originate between the
of vascular complication is the L4-5 disk space with reported vas- ninth intercostal (thoracic) artery and the second lumbar artery,
cular injury rates of 2% to 15%. At this level the left iliac artery most commonly on the left side. Cadaveric studies have shown
is at risk since it must be mobilized for adequate exposure of the little variation in the course of the lumbar arteries, although the
disk space. The iliac veins are also susceptible to injury at this level number present varied (2–4).8 Injury to even these small vessels
as they are mobilized.4 The left iliac vein and iliocaval junction can lead to complications. Santillan et al.9 reported a vascular
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30 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
L4 artery
and vein
L5
L5 artery
and vein
Internal iliac artery
External iliac artery Medial sacral artery and vein
• Fig. 4.5 Anterior view of the lumbar spine demonstrating anatomical variation in the location of the
aorta, inferior vena cava, and their branches. (From Benzel E. Spine Surgery: Techniques, Complication
Avoidance, & Management, ed 3, Philadelphia: Elsevier Saunders; 2012; Figure 36-12.)
injury of the left L2 segmental artery after an L2-3 eXtreme lateral successful endovascular embolization of a left L-2 segmental artery
interbody fusion procedure thought to be caused by the lateral pseudoaneurysm.9
expandable split retractor blade. The injury was discovered 48
hours postoperatively when the patient became hemodynamically Venous Drainage of the Spine
unstable and a computed tomography scan showed a large left
retroperitoneal hematoma. Immediately, the patient underwent a A large valveless venous plexus is responsible for drainage of
the spine (Fig. 4.7). This plexus has external and epidural
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CHAPTER 4 Relevant Surgical Anatomy of the Lateral and Anterior Lumbar Spine 31
Dorsal branch of
intercostal artery
7 Th
8 Posterior
intercostal Aorta
9
arteries Intercostal artery
10 Segmental Spinal branch
artery
11 Left segmental
artery
12 Subcostal
artery Aorta
2 Radiculomedullary
Lumbar
artery
arteries
3 Neural branch
L
4
Spinal nerve
Aorta Segmental
Spinal branch
artery
A B
• Fig. 4.6 A. Arterial supply to the spine. The aorta originating on the anterolateral left side of the thoracic
spine and crossing to a more medial location. B. The segmental and spinal branches passing around the
vertebral body and entering the dura at the site of the nerve root. (From Benzel E. Spine Surgery: Tech-
niques, Complication Avoidance, & Management. 3rd ed. Philadelphia: Elsevier Saunders; 2012; Figure
32-24.)
components, and has portions both ventrally and dorsally. Intra- crosses over the common iliac artery.11 Vigilance in identifying
dural venous drainage is performed by the radiculomedullary the ureter may help prevent injury by dissection during the
veins which feed into the anterior and posterior spinal veins. The approach or by retraction.
venous system closely parallels the arterial system. The lumbar
veins travel with the lumbar arteries but with greater variation in Neural Anatomy
course and number. Cadaveric studies frequently identify veins
on the left side.8 In the average adult the spinal cord terminates at the L1 level, giv-
ing rise to the conus medullaris and the nerve roots of the cauda
Urinary System equina. As the dorsal and ventral roots exit the spinal cord, they join
to form the spinal nerve in the dural sleeve. This nerve then exits
The kidneys and the ureters lie within the retroperitoneal below the pedicle with the same number (Fig. 4.8). These nerves
space in proximity to the spine and may also be at risk during then join to form the lumbar plexus within the psoas major and
the lateral and anterior approaches. The left kidney is more give rise to the sensory and motor innervation of the abdomen and
caudal than the right with the upper pole on the left at the proximal leg (Fig. 4.9). The ilioinguinal and iliohypogastric nerves
level of T11-12 and the lower pole at L2-3. The upper pole originate from L1 and pass laterally and anteriorly into the abdo-
of the right kidney is typically at T12-L1, and the lower pole men. The genitofemoral nerve (from L1 and L2) exits the ventral
at L3-4.10 The ureters exit the renal pelvis and travel postero- psoas and later divides into two femoral and genital branches, lat-
laterally on the anterior surface of the psoas muscle. The right eral to the common and iliac arteries. The lateral femoral cutaneous
ureter courses along the right aspect of the IVC and crosses nerve arises from the L1 and L2 roots. The largest branches of the
the external iliac artery as it enters the pelvis. The left ureter lumbar plexus, which provide motor function to the proximal leg,
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32 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
are the obturator and femoral nerves, which arise from L2, L3, and genitofemoral nerve is in the middle third. Perforating branches of
L4. L4 and L5 combine to form the lumbosacral trunk and join the the lumbar nerve roots can be found in all thirds.
first sacral nerve. The obturator nerve lies medial to the psoas and is Other studies have divided the vertebral body into six zones:
not at risk during lateral transpsoas approaches. The femoral nerve A is the most anterior at the anterior border of the vertebral body,
is very much at risk, particularly at the L4-5 level. followed by zones 1–4, and then zone P, the most posterior defined
as the posterior border of the vertebral body.13 The more superior
disk levels have a larger safe zone than at L4-5 where only the
Defining a Safe Corridor anterior fourth (zone 1) is safe for a right-sided approach, whereas
With the growing popularity of minimally invasive approaches zones 2 and 3 define the safe corridor in a left-sided approach.6,13
where visualization of the regional anatomy is limited, many authors Radiographic and cadaveric studies have increased our knowl-
have attempted to define safe corridors to allow access to the spine edge of the anatomy and normal variants of the lumbar spine and
with minimal risk of complications. After the spinal nerves exit the surrounding structures. One cadaveric study measured the ratio of
lateral foramen, they traverse the lateral surface of the spine and the distance from the posterior endplate of the disk space to the
form the plexus within the psoas muscle. The minimally invasive lat- total length of the disk space. This study demonstrated the ven-
eral approach to the lumbar spine requires traversing the ipsilateral tral migration of the lumbosacral plexus from the posterior border
psoas muscle with, dilators and retractors; the location of the nerves of the disk space at L1-2 (ratio = 0) to a more anterior position
and plexus places them at risk during this approach. Both cadaveric (ratio = 0.28) at L4-5 moving caudally through the lumbar spine.
and radiographic studies have been performed in attempts to define The safe working zone at L2-3 and L3-4 is in the anterior three-
a safe working corridor for this approach. This surgical approach fourth of the disk space but with the ventral migration of the
was mimicked in cadavers; in 25% of mimicked cases, nerve dam- plexus, this decreases to the anterior two-thirds at L4-5. At this
age occurred owing to piercing either a lumbar nerve root or the level the nerve root is at the greatest risk of injury.14 Another study
genitofemoral nerve. Dilation of the retractor resulted in stretch on focused on the neural structures, identifing zone 3 as a safe area
the lumbar nerve roots in all cases.12 One simple scheme describ- for an approach from L1-2, L2-3, and L3-4. However, at L4-5
ing the anatomy divides the psoas muscle into thirds. The sympa- the safe area of approach was the border between zone 2 and zone
thetic chain travels in the anterior one-third of the psoas muscle; the 3, at the midpoint of the vertebral body. Specific analysis of the
Inferior
vena cava
Intervertebral
vein
Dorsal branch
Common iliac vein
Posterior
External intercostal vein Internal iliac vein
vertebral Hemiazygos vein
venous plexus
A B
• Fig. 4.7 Venous drainage of the spine. A. The internal and external venous plexuses in relation to the
vertebral body. B. The inferior vena cava passes on the anterolateral surface of the lumbar spine, to the
right of midline. (From Benzel E. Spine Surgery: Techniques, Complication Avoidance, & Management,
3rd ed. Philadelphia: Elsevier Saunders; 2012; Figure 32-27.)
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CHAPTER 4 Relevant Surgical Anatomy of the Lateral and Anterior Lumbar Spine 33
Phrenic nerve
Vena cava
Esophagus
Greater
splanchic nerve Aorta
Medial crus
Lateral arcuate ligament
Subcostal nerve
Twelfth rib
Medial arcuate ligament
Iliohypogastric nerve Quadratus lumborum
Ilioinguinal nerve muscle
L5
Sympathetic trunk
• Fig. 4.9 The spine as seen (anterior view) with the blood vessels removed. The sympathetic chain is on
the anterior surface. The nerves of the lumbar plexus are seen exiting from the psoas major. (From Benzel
E. Spine Surgery: Techniques, Complication Avoidance, & Management, 3rd ed. Philadelphia: Elsevier
Saunders; 2012; Figure 36-11.)
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34 SE C T I O N 2 Anatomy and Intraoperative Imaging for Lumbar Interbody Fusion
Vena cava
Aorta
Superior
hypogastric
plexus
• Fig. 4.10 The superior hypogastric plexus and variations. (From Benzel E. Spine Surgery: Techniques,
Complication Avoidance, & Management, 3rd ed., Philadelphia: Elsevier Saunders; 2012; Figure 36-9.)
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CHAPTER 4 Relevant Surgical Anatomy of the Lateral and Anterior Lumbar Spine 35
10. Currarino G, Winchester P. Position of the kidneys relative to the 16. Park DK, Lee MJ, Lin EL, et al. The relationship of intrapsoas nerves
spine, with emphasis on children. Am J Roentgenol Radium Ther Nucl during a transpsoas approach to the lumbar spine: anatomic study.
Med. 1965;95(2):409–412. J Spinal Disord Tech. 2010;23(4):223–228. https://doi.org/10.1097/
11. Chan JK, Morrow J, Manetta A. Prevention of ureteral injuries in gyne- BSD.0b013e3181a9d540.
cologic surgery. Am J Obstet Gynecol. 2003;188(5):1273–1277. PubMed 17. Regev GJ, Chen L, Dhawan M, et al. Morphometric analysis of
PMID: 12748497. the ventral nerve roots and retroperitoneal vessels with respect to
12. Banagan K, Gelb D, Poelstra K, Ludwig S. Anatomic mapping of lum- the minimally invasive lateral approach in normal and deformed
bar nerve roots during a direct lateral transpsoas approach to the spine: spines. Spine (Phila Pa 1976). 2009;34(12):1330–1335. https://doi.
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21217450. lowing the minimally invasive lateral transpsoas approach. J Neuro-
13. Moro T, Kikuchi S, Konno S, et al. An anatomic study of the lum- surg Spine. 2012;17(3):227–231. https://doi.org/10.3171/2012.5.
bar plexus with respect to retroperitoneal endoscopic surgery. Spine SPINE1288.
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sacral plexus as related to the minimally invasive transpsoas approach 009-0461-7.
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Navigation for Lumbar Interbody Fusion
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banishing melancholy remembrances by launching into cheerful
conversation, when the gallery door was suddenly opened, and the
Queen rose, exclaiming, ‘The King here already!’ When, however,
she saw that, instead of the King, it was only the Prince of Wales,
and ‘detesting the exchange of the son for the daughter, she burst
out anew into tears, and cried out, “Oh, God! this is too much!”’ She
was only relieved by the entry of the King, who, perceiving but not
speaking to his son, took the Queen by the hand and led her out to
walk.
This ‘cut direct,’ by affecting to be unconscious of the presence
of the obnoxious person, was a habit with the King. ‘Whenever the
prince was in a room with him,’ says Lord Hervey, ‘it put one in mind
of stories that one has heard of ghosts which appear to part of the
company and were invisible to the rest; and in this manner, wherever
the prince stood, though the King passed him ever so often, or ever
so near, it always seemed as if the King thought the prince filled a
void space.’
On the following day, the 22nd of October, the Princess Anne
suddenly appeared before her parents. They thought her at Harwich,
or on the seas, the wind being fair. Tears and kisses were her
welcome from her mother, and smiles and an embrace formed the
greeting from her father. The return was ill-advised, but the Queen,
with a growing conviction of decaying health, could not be
displeased at seeing again her first child.
The health of Caroline was undoubtedly at this time much
impaired, but the King allowed her scant respite from labour on that
account. Thus on the 29th of this month, although the Queen was
labouring under cold, cough, and symptoms of fever, in addition to
having been weakened by loss of blood, a process she had recently
undergone twice, the King not only brought her from Kensington to
London for the birthday, but forced her to go with him to the opera to
hear the inimitable Farinelli. He himself thought so little of illness, or
liked so little to be thought ill, that he would rise from a sick couch to
proceed to hold a levée, which was no sooner concluded than he
would immediately betake himself to bed again. His affection for the
Queen was not so great but that he compelled the same sacrifices
from her; and on the occasion of this birthday, at the morning
drawing-room, she found herself so near swooning, that she was
obliged to send her chamberlain to the King, begging him to retire,
‘for she was unable to stand any longer.’ Notwithstanding which, we
are told by Lord Hervey, that ‘at night he brought her into a still
greater crowd at the ball, and there kept her till eleven o’clock.’
Sir Robert Walpole frequently, and never more urgently than at
this time, impressed upon her the necessity of being careful of her
own health. He addressed her as though she had been Queen
Regnant of England—as she certainly was governing sovereign—
and he described to her in such pathetic terms the dangers which
England would, and Europe might, incur, if any fatal accident
deprived her of life, and the King were to fall under the influence of
any other woman, that the poor Queen, complaining and coughing,
with head heavy, and aching eyes half closed with pain, cheeks
flushed, pulse quick, spirits low, and breathing oppressed, burst into
tears, alarmed at the picture, and with every disposition to do her
utmost for the benefit of her health and the well-being of the body
politic.
It was the opinion of Caroline, that in case of her demise the
King would undoubtedly marry again, and she had often advised him
to take such a step. She affected, however, to believe that a second
wife would not be able to influence him to act contrary to the system
which he had adopted through the influence of herself and Walpole.
It was during the sojourn of the Princess Anne in England that
she heard the details of the withdrawal of Lady Suffolk from court.
Everybody appeared to be rejoiced at that lady’s downfall, but most
of all the Princess Anne. The King thought that of all the children of
himself and Caroline, Anne loved him best. This dutiful daughter,
however, despised him, and treated him as an insufferable bore, who
always required novelty in conversation from others, but never told
anything new of his own. In allusion to the withdrawal of Lady Suffolk
from court, this amiable child remarked, ‘I wish with all my heart he
would take somebody else, that Mamma might be a little relieved
from the occasion of seeing him for ever in her room!’
In November the Princess Anne once more proceeded to
Harwich, put to sea, and was so annoyed by the usual
inconveniences that she compelled the captain to land her again.
She declared that she should not be well enough for ten days to go
once more aboard. This caused great confusion. Her father, and
indeed the Queen also, insisted on her repairing to Holland by way
of Calais, as her husband had thoughtfully suggested. She was
compelled to pass through London, much to the King’s annoyance,
but he declared that she should not stop, but proceed at once over
London Bridge to Dover. He added, that she should never again
come to England in the same condition of health. His threat was
partly founded on the expense, her visit having cost him 20,000l. Her
reluctance to proceed to her husband’s native country was founded,
it has been suggested, on her own ambitious ideas. Her brothers
were unmarried, and she was anxious, it is thought, that her own
child should be English born, as it would stand in the line of
inheritance to the throne. However this may be, the Queen saw the
false step the daughter had already taken, and insisted on the
wishes of her husband, the prince, being attended to; and so the
poor foiled Anne went home to become a mother, very much against
her will.
The Princess Amelia observed to Mrs. Clayton, the Queen’s
bedchamber-woman, that her brother, Prince Frederick, would have
been displeased if the accouchement of the princess had taken
place in England. To this, Mrs. Clayton, as Lord Hervey observes,
very justly remarked, ‘I cannot imagine, madam, how it can affect the
prince at all where she lies in; since with regard to those who wish
more of your royal highness’s family on the throne, it is no matter
whether she be brought to bed here or in Holland, or of a son or a
daughter, or whether she has any child at all; and with regard to
those who wish all your family well, for your sake, madam, as well as
our own, we shall be very glad to take any of you in your turn, but
none of you out of it.’
But the Queen had other business this year wherewith to occupy
her besides royal marriages, or filial indispositions. In some of these
matters her sincerity is sadly called in question. Here is an instance.
In 1734 the Bishop of Winchester was stricken with apoplexy,
and Lord Hervey was no sooner aware of that significant fact—it was
a mortal attack—than he wrote to Hoadly at Salisbury, urging him in
the strongest terms to make application to be promoted from Sarum
to the almost vacant see.
This promotion had been promised him by the King, Queen, and
Walpole, all of whom joined in blandly reproving the bishop for being
silent when Durham was vacant, whereby alone he lost that golden
appointment. He had served government so well, and yet had
contrived to maintain most of his usual popularity with the public, that
he had been told to look upon Winchester as his own, whenever an
opening occurred.
Hoadly was simple enough to believe that the Queen and
Walpole were really sincere. He addressed a letter to the King
through his ‘two ears’—the Queen and Walpole; and he wrote as if
he were sure of being promoted, according to engagement, while at
the same time he acted as if he were sure of nothing.
Caroline called the bishop’s letter indelicate, hasty, ill-timed, and
such like; but Hoadly so well obeyed the instructions given to him
that there was no room for escape, and he received the
appointment. When he went to kiss hands upon his elevation, the
King was the only one who behaved with common honesty. He, and
Caroline too, disliked the man, whom the latter affected a delight to
honour, for the reason that his respect for royalty was not so great as
to blind him to popular rights, which he supported with much
earnestness. On his reception by the King, the latter treated him with
disgraceful incivility, exactly in accordance with his feelings. Caroline
did violence to hers, and gave him honeyed words, and showered
congratulations upon him, and pelted him, as it were, with
compliments and candied courtesy. As for Sir Robert Walpole, who
hated Hoadly as much as his royal mistress and her consort did
together, he took the new Bishop of Winchester aside, and, warmly
pressing his hand, assured him without a blush that his translation
from Sarum to Winchester was entirely owing to the mediation of
himself, Sir Robert. It was a daring assertion, and Sir Robert would
have hardly ventured upon making it had he known the share Lord
Hervey had had in this little ecclesiastical intrigue. Hoadly was not
deluded by Walpole, but he was the perfect dupe of the Queen.
16
Lord Mahon, in speaking of Caroline, says that ‘her character
was without a blemish.’ Compared with many around her, perhaps it
was; but if the face had not spots it had ‘patches,’ which looked very
much like them. On this matter, the noble lord appears to admit that
some doubt may exist, and he subsequently adds: ‘But no doubt can
exist as to her discerning and most praiseworthy patronage of worth
and learning in the Church. The most able and pious men were
everywhere sought and preferred, and the episcopal bench was
graced by such men as Hare, Sherlock, and Butler.’ Of course,
Queen Caroline’s dislike of Hoadly may be set down as founded
upon that prelate’s alleged want of orthodoxy. It has been noticed in
another page, that, according to Walpole, the Queen had rather
weakened than enlightened her faith by her study of divinity, and that
her Majesty herself ‘was at best not orthodox.’ Her countenance of
the ‘less-believing’ clergy is said, upon the same authority, to have
been the effect of the influence of Lady Sundon, who ‘espoused the
heterodox clergy.’
Lord Mahon also says that the Queen was distinguished for
charity towards those whom she accounted her enemies. She could
nurse her rage, however, a good while to keep it warm. Witness her
feeling manifested against that daughter of Lord Portland who
married Mr. Godolphin. Her hatred of this lady was irreconcileable,
nor was the King’s of a more Christian quality. That lady’s sole
offence, however, was her acceptance of the office ‘of governess to
their daughter in the late reign, without their consent, at the time they
had been turned out of St. James’s, and the education of their
17
children, who were kept there, taken from them.’ For this offence
the King and Queen were very unwilling to confer a peerage and
pension on Godolphin in 1735, when he resigned his office of groom
of the stole in the royal household. The peerage and pension were,
nevertheless, ultimately conferred at the earnest solicitation of
Walpole, and with great ill-humour on the part of the King.
Even Walpole, with all his power and influence, was not at this
time so powerful and influential but that when he was crossed in
parliament he suffered for it at court. Thus, when the Crown lost
several supporters in the house by adverse decisions on election
petitions, the King was annoyed, and the Queen gave expression to
her own anger on the occasion. It was rare indeed that she ever
spoke her dissatisfaction of Sir Robert; but on the occasion in
question she is reported as having said that Sir Robert Walpole
either neglected these things, and judged it enough to think they
were trifles, though in government, and especially in this country,
nothing was a trifle, ‘or, perhaps,’ she said, ‘there is some
mismanagement I know nothing of, or some circumstances we are
none of us acquainted with; but, whatever it is, to me these things
18
seem very ill-conducted.’
The Queen really thought that Walpole was on the point of
having outlived his ability and his powers to apply it for the benefit of
herself and husband. She observed him melancholy, and set it down
that he was mourning over his own difficulties and failures. When
Caroline, however, was told that Sir Robert was not in sorrow
because of the difficulties of government, but simply because his
mistress, Miss Skerret, was dangerously ill of a pleuritic fever, the
‘unblemished Queen’ was glad! She rejoiced that politics had nothing
to do with his grief, and she was extremely well pleased to find that
the prime-minister was as immoral as men of greater and less
dignity. And then she took to satirising both the prime-minister and
the lady of his homage. She laughed at him for believing in the
attachment of a woman whose motives must be mercenary, and who
could not possibly see any attraction in such a man but through the
meshes of his purse. ‘She must be a clever gentlewoman,’ said
Caroline, ‘to have made him believe that she cares for him on any
other score; and to show you what fools we all are on some point or
other, she has certainly told him some fine story or other of her love,
and her passion, and that poor man, with his burly body, swollen
legs, and villainous stomach (“avec ce gros corps, jambes enflés, et
ce vilain ventre”) believes her!—ah, what is human nature?’ On this
rhapsody Lord Hervey makes a comment in the spirit of Burns’
verse—
and it was excellent opportunity for such comment. ‘While she was
saying this,’ remarks the noble lord, ‘she little reflected in what
degree she herself possessed all the impediments and antidotes to
love she had been enumerating, and that, “Ah, what is human
nature?” was as applicable to her own blindness as to his.’
She certainly illustrated in her own person her assertion that in
government nothing was a trifle. Thus, when what was called the
Scotch Election Petition was before parliament and threatening to
give some trouble to the ministerial side, her anxiety till the question
was decided favourably to the Crown side, and her affected
indifference after the victory, were both marked and striking. On the
morning before the petition was presented, praying the House of
Lords to take into consideration certain alleged illegalities in the
recent election of sixteen representative peers of Scotland—a
petition which the house ultimately dismissed—the anxiety of
Caroline was so great ‘to know what was said, thought, or done, or
expected on this occasion, that she sent for Lord Hervey while she
was in bed; and because it was contrary to the queenly etiquette to
admit a man to her bedside while she was in it, she kept him talking
upon one side of the door, which was just upon her bed, while she
conversed with him on the other for two hours together, and then
sent him to the King’s side to repeat to his Majesty all he had related
19
to her.’ By the King’s side is meant, not his Majesty’s side of the
royal couch, but the side of the palace wherein he had his separate
apartments.
It was soon after this period (1735), that the King set out for
Hanover, much against the inclination of his ministers, who dreaded
lest he should be drawn in to conclude some engagement, when
abroad, adverse to the welfare of England. His departure, however,
was witnessed by Caroline with much resignation. It gave her
infinitely more power and more pleasure; for, as regent, she had no
superior to consult or guide, and in her husband’s absence she had
not the task of amusing a man who was growing as little amusable
as Louis XIV. was when Madame de Maintenon complained of her
terrible toil in that way. His prospective absence of even half a year’s
duration did not alarm Caroline, for it released her from receiving the
daily sallies of a temper that, let it be charged by what hand it would,
used always to discharge its hottest fire, on some pretence or other,
upon her!
The Queen’s enjoyment, however, was somewhat dashed by
information conveyed to her by that very husband, and by which she
learned that the royal reprobate, having become smitten by the
attractions of a young married German lady, named Walmoden, had
had the rascality to induce her to leave her husband—a course
which she had readily adopted for the small consideration of a
thousand ducats.
This Madame Walmoden brings us back to the times of Sophia
Dorothea. Elizabeth, sister of the Countess von Platen who brought
about the catastrophe in which Königsmark perished and Sophia
Dorothea was ruined, was married, first to von Busch, and secondly
to von Weyhe (or Weyke). By this second marriage she had a
daughter, who became the wife of General von Wendt. These von
Wendts had a daughter also, who married Herr Walmoden. It was
this last lady whom the son of Sophia Dorothea lured from her
husband, and whom he ultimately raised to the dignity of Countess
of Yarmouth.
Not the smallest incident which marked the progress of this
infamous connection was concealed by the husband from his wife.
He wrote at length minute details of the person of the new mistress,
for whom he bespoke the love of his own wife!
Lord Hervey thinks that the pride of the Queen was much more
hurt than her affections on this occasion; which is not improbable, for
the reasoning public, to whom the affair soon became known, at
once concluded that the rise of the new mistress would be attended
with the downfall of the influence of Caroline.
The latter, however, knew well how to maintain her influence, let
who would be the object of the impure homage of her exceedingly
worthless husband. To the letters which he addressed to her with
particular unction, she replied with an unction quite as rich in quality
and profuse in degree. Pure and dignified as she might seem in
discoursing with divines, listening to philosophers, receiving the
metrical tributes of poets, or cavilling with scholars, she had no
objection to descend from Olympus and find relaxation in wallowing
in Epicurus’ stye. Nor did she thus condescend merely to suit a
purpose and to gain an end. Her letters, encouraging her husband in
his amours with women at Hanover, were coarse enough to have
called up a blush on the cheek of one of Congreve’s waiting-maids.
They have the poor excuse tied to them of having been written for
the purpose of securing her own power. The same apology does not
apply to the correspondence with the dirty Duchess of Orleans.
Caroline appears to have indulged in the details of that
correspondence for the sake of the mere pleasure itself. And yet she
has been called a woman without blemish!
The King’s letters to her are said to have extended to sixty, and
never to less than forty, pages. They were filled, says Lord Hervey,
‘with an hourly account of everything he saw, heard, thought, or did,
and crammed with minute trifling circumstances, not only unworthy
of a man to write, but even of a woman to read; most of which I saw,
and almost all of them I heard reported by Sir Robert Walpole, to
whose perusal few were not committed, and many passages were
transmitted to him by the King’s own order; who used to tag several
paragraphs with “Montrez ceci et consultez ladessus le gros
homme.” Among many extraordinary things and expressions these
letters contained was one in which he desired the Queen to contrive,
if she could, that the Prince of Modena, who was to come at the
latter end of the year to England, might bring his wife with him.’ She
was the younger daughter of the Regent Duke of Orleans. The
reason which the King gave to his wife for the request which he had
made with respect to this lady was, that he had understood the latter
was by no means particular as to what quarter or person she
received homage from, and he had the greatest inclination
imaginable to pay his addresses to a daughter of the late Regent of
France. ‘Un plaisir,’ he said—for this German husband wrote even to
his German wife in French—‘que je suis sûr, ma chère Caroline,
vous serez bien aise de me procurer, quand je vous dis combien je
le souhaite!’ If Wycherley had placed such an incident as this in a
comedy, he would have been censured as offending equally against
modesty and probability.
In the summer of this year, Lord Hervey was absent for a while
from attendance on his royal mistress; but we may perhaps learn
from one of his letters, addressed to her while he was resting in the
country from his light labours, the nature of his office and the way in
which Caroline was served. The narrative is given by the writer as
part of an imaginary post-obit diary, in which he describes himself as
having died on the day he left her, and as having been repeatedly
buried in the various dull country houses by whose proprietors he
was hospitably received. He thus proceeds:—
‘But whilst my body, madam, was thus disposed of, my spirit (as
when alive) was still hovering, though invisible, round your Majesty,
anxious for your welfare, and watching to do you any little service
that lay within my power.
‘On Monday, whilst you walked, my shade still turned on the side
of the sun to guard you from its beams.
‘On Tuesday morning, at breakfast, I brushed away a fly that had
escaped Teed’s observation’ (Teed was one of the Queen’s
attendants) ‘and was just going to be the taster of your chocolate.
‘On Wednesday, in the afternoon, I took off the chillness of some
strawberry-water your Majesty was going to drink as you came in hot
from walking; and at night I hunted a bat out of your bedchamber,
and shut a sash just as you fell asleep, which your Majesty had a
little indiscreetly ordered Mrs. Purcel to leave open.
‘On Thursday, in the drawing-room, I took the forms and voices
of several of my acquaintances, made strange faces, put myself into
awkward postures, and talked a good deal of nonsense, whilst your
Majesty entertained me very gravely, recommended me very
graciously, and laughed at me internally very heartily.
‘On Friday, being post-day, I proposed to get the best pen in the
other world for your Majesty’s use, and slip it invisibly into your
standish just as Mr. Shaw was bringing it into your gallery for you to
write; and accordingly I went to Voiture, and desired him to hand me
his pen; but when I told him for whom it was designed, he only
laughed at me for a blockhead, and asked me if I had been at court
for four years to so little purpose as not to know that your Majesty
had a much better of your own.
‘On Saturday I went on the shaft of your Majesty’s chaise to
Richmond; as you walked there I went before you, and with an
invisible wand I brushed the dew and the worms out of your path all
the way, and several times uncrumpled your Majesty’s stocking.
‘Sunday.—This very day, at chapel, I did your Majesty some
service, by tearing six leaves out of the parson’s sermon and
shortening his discourse six minutes.’
While these imaginary services were being rendered by the
visionary Lord Hervey to the Queen, realities more serious and not
less amusing were claiming the attention of Caroline and her
consort.
In return for the information communicated by the King to the
Queen on the subject of Madame Walmoden and her charms,
Caroline had to inform her husband of the marriage we have spoken
of between Lady Suffolk and Mr. George Berkeley. The royal ex-lover
noticed the communication in his reply in a coarse way, and
expressed his entire satisfaction at being rid of the lady, and at the
lady’s disposal of herself.
When Caroline informed her vice-chamberlain, Lord Hervey, of
the report of this marriage, his alleged disbelief of the report made
her peevish with him, and induced her to call him an ‘obstinate devil,’
who would not believe merely improbable facts to be truths. Caroline
then railed at Lady Suffolk in good set terms as a sayer and doer of
silly things, entirely unworthy of the reputation she had with some
people of being the sayer and doer of wise ones.
It was on this occasion that Caroline herself described to Lord
Hervey the farewell interview she had had with Lady Suffolk. The ex-
mistress took a sentimental view of her position, and lamented to the
wife that she, the mistress, was no longer so kindly treated as
formerly by the husband. ‘I told her,’ said the Queen, ‘in reply, that
she and I were not of an age to think of these sort of things in such a
romantic way, and said, “My good Lady Suffolk, you are the best
servant in the world; and, as I should be most extremely sorry to lose
you, pray take a week to consider of this business, and give me your
word not to read any romances in that time, and then I dare say you
will lay aside all thoughts of doing what, believe me, you will repent,
20
and what I am very sure I shall be very sorry for.”’ It was at one of
these conversations with Lord Hervey that the Queen told him that
Lady Suffolk ‘had had 2,000l. a year constantly from the King whilst
he was prince, and 3,200l. ever since he was King; besides several
little dabs of money both before and since he came to the crown.’
A letter of Lady Pomfret’s will serve to show us not only a picture
of the Queen at this time, but an illustration of feeling in a fine lady.
Lady Pomfret, writing to Lady Sundon, in 1735, says: ‘All I can
say of Kensington is, that it is just the same as it was, only pared as
close as the bishop does the sacrament. My Lord Pomfret and I were
the greatest strangers there; no secretary of state, no chamberlain or
vice-chamberlain, but Lord Robert, and he just in the same coat, the
same spot of ground, and the same words in his mouth that he had
when I left there. Mrs. Meadows in the window at work; but, though
half an hour after two, the Queen was not quite dressed, so that I
had the honour of seeing her before she came out of her little blue
room, where I was graciously received, and acquainted her Majesty,
to her great sorrow, how ill you had been; and then, to alleviate that
sorrow, I informed her how much Sundon was altered for the better,
and that it looked like a castle. From thence we proceeded to a very
short drawing-room, where the Queen joked much with my Lord
Pomfret about Barbadoes. The two ladies of the bedchamber and
the governess are yet on so bad a foot, that upon the latter coming
into the room to dine with Lady Bristol, the others went away, though
just going to sit down, and strangers in the place.’
The writer of this letter soon after lost a son, the Honourable
Thomas Fermor. It was a severely felt loss; so severe that some
weeks elapsed before the disconsolate mother was able, as she
says, ‘to enjoy the kind and obliging concern’ expressed by the
Queen’s bedchamber-woman in her late misfortune. Christianity
itself, as this charming mother averred, would have authorised her in
lamenting such a calamity during the remainder of her life; but then,
oh joy! her maternal lamentation was put an end to and Rachel was
comforted, and all because—‘It was impossible for any behaviour to
be more gracious than that of the Queen on this occasion, who
made it quite fashionable to be concerned’ at the death of Lady
Pomfret’s son.
But there were more bustling scenes at Kensington than such as
those described by this fashionably sorrowing lady and the
sympathising sovereign.
On Sunday, the 26th of October, the Queen and her court had
just left the little chapel in the palace of Kensington, when intimation
was given to her Majesty that the King, who had left Hanover on the
previous Wednesday, was approaching the gate. Caroline, at the
head of her ladies and the gentlemen of her suite, hastened down to
receive him; and, as he alighted from his ponderous coach, she took
his hand and kissed it. This ceremony performed by the regent, a
very unceremonious, hearty, and honest kiss was impressed on his
lips by the wife. The King endured the latter without emotion, and
then, taking the Queen-regent by the fingers, he led her upstairs in a
very stately and formal manner. In the gallery there was a grand
presentation, at which his Majesty exhibited much ill-humour, and
conversed with everybody but the Queen.
His ill-humour arose from various sources. He had heated
himself by rapid and continual travelling, whereby he had brought on
an attack of a complaint to which he was subject, which made him
very ill at ease, and which is irritating enough to break down the
patience of the most patient of people.
On ordinary occasions of his return from Hanover his most
sacred Majesty was generally of as sour disposition as man so little
heroic could well be. He loved the Electorate better than he did his
kingdom, and would not allow that there was anything in the latter
which could not be found in Hanover of a superior quality. There was
no exception to this: men, women, artists, philosophers, actors,
citizens, the virtues, the sciences, and the wits, the country, its
natural beauties and productions, the courage of the men and the
attractions of the women—all of these in England seemed to him
worthless. In Hanover they assumed the guise of perfection.
This time he returned to his ‘old’ wife laden with a fresh sorrow—
the memory of a new favourite. He had left his heart with the
insinuating Walmoden, and he brought to his superb Caroline
nothing but a tribute of ill-humour and spite. He hated more than
ever the change from an Electorate where he was so delightfully
despotic, to a country where he was only chief magistrate, and
where the people, through their representatives, kept a very sharp
watch upon him in the execution of his duties. He was accordingly as
coarse and evil-disposed towards the circle of his court as he was to
her who was the centre of it. He, too, was like one of those
pantomime potentates who are for ever in King Cambyses’ vein, and
who sweep through the scene in a whirlwind of farcically furious
words and of violent acts, or of threats almost as bad as if the
menaces had been actually realised. It was observed that his
behaviour to Caroline had never been so little tinged with outward
respect as now. She bore his ill-humour with admirable patience; and
her quiet endurance only the more provoked the petulance of the
little and worthless King.
He was not only ill-tempered with the mistress of the palace, but
was made, or chose to think himself, especially angry at trifling
improvements which Caroline had carried into effect in the suburban
palace during the temporary absence of its master. The
improvements consisted chiefly in removing some worthless pictures
and indifferent statues and placing master-pieces in their stead. The
King would have all restored to the condition it was in when he had
last left the palace; and he treated Lord Hervey as a fool for
venturing to defend the Queen’s taste and the changes which had
followed the exercise of it. ‘I suppose,’ said the dignified King to the
courteous vice-chamberlain, ‘I suppose you assisted the Queen with
your fine advice when she was pulling my house to pieces, and
spoiling all my furniture. Thank God! at least she has left the walls
standing!’
Lord Hervey asked if he would not allow the two Vandykes which
the Queen had substituted for ‘two signposts,’ to remain. George
pettishly answered, that he didn’t care whether they were changed or
no; ‘but,’ he added, ‘for the picture with the dirty frame over the door,
and the three nasty little children, I will have them taken away, and
the old ones restored. I will have it done, too, to-morrow morning,
before I go to London, or else I know it will not be done at all.’
Lord Hervey next enquired if his Majesty would also have ‘his
gigantic fat Venus restored too?’ The King replied that he would, for
he liked his fat Venus better than anything which had been put in its
place. Upon this Lord Hervey says he fell to thinking ‘that if his
Majesty had liked his fat Venus as well as he used to do, there would
have been none of these disputations.’
By a night’s calm repose the ill-humour of the Sovereign was not
dispersed. On the following morning we meet with the insufferable
little man in the gallery, where the Queen and her daughters were
taking chocolate; her son, the Duke of Cumberland, standing by. He
only stayed five minutes, but in that short time the husband and
father contrived to wound the feelings of his wife and children. ‘He
snubbed the Queen, who was drinking chocolate, for being always
stuffing; the Princess Amelia for not hearing him; the Princess
Caroline for being grown fat; the Duke of Cumberland for standing
awkwardly; and then he carried the Queen out to walk, to be re-
21
snubbed in the garden.’
Sir Robert Walpole told his friend Hervey that he had done his
utmost to prepare the Queen for this change in the King’s feelings
and actions towards her. He reminded her that her personal
attractions were not what they had been, and he counselled her to
depend more upon her intellectual superiority than ever. The virtuous
man advised her to secure the good temper of the King by throwing
certain ladies in his way of an evening. Sir Robert mentioned, among
others, Lady Tankerville, ‘a very safe fool, who would give the King
some amusement without giving her Majesty any trouble.’ Lady
Deloraine, the Delia from whose rage Pope bade his readers dread
slander and poison, had already attracted the royal notice, and the
King liked to play cards with her in his daughter’s apartments. This
lady, who had the loosest tongue of the least modest women about
the court, was characterised by Walpole as likely to exercise a
dangerous influence over the King. If Caroline would retain her
power, he insinuated, she must select her husband’s favourites,
through whom she might still reign supreme.
Caroline is said to have taken this advice in good part. There
would be difficulty in believing that it ever was given did we not know
that the Queen herself could joke, not very delicately, in full court, on
her position as a woman not first in her husband’s regard. Sir Robert
would comment on these jokes in the same locality, and with
increase of coarseness. The Queen, however, though she affected
to laugh, was both hurt and displeased—hurt by the joke and
displeased with the joker, of whom Swift has said, that—