Assessment PDF
Assessment PDF
Assessment PDF
Abstract: Accurate and non-invasive measurements are essential for deformity diagnosis and
assessment of curve progression. Although the standard procedure for diagnosis and follow-up of the
progression of scoliosis is the Cobb method of radiographic measurement, there is much concern
related to the multiple exposures to ionizing radiation. Ortelius 800TM is a unique device that allows
radiation-free, simple and accurate assessment of spinal deformities. Preliminary analysis of the
clinical value of Ortelius 800TM for analysis of spinal deformities was performed on patients with
scoliosis ranging from 10 to 46 degrees. Correspondence between Cobb angles measured on direct
radiographs and those calculated by Ortelius 800TM were estimated by Pearsons correlation
coefficient showing a significant correlation and a mean difference of 3.6 degrees. Preliminary results
are promising, implicating that the use of Ortelius 800TM is of clinical value and can reduce the
number of radiographs required in the monitoring of scoliosis patients.
A
system
providing
radiation-free
monitoring that is repeatable and reliable
would be of great clinical value. The
development of Ortelius 800TM addresses
this need. Ortelius 800TM is based on direct
measurement of the patients back with a
fingertip scanner. The fingertip scanner is
Figure 1: General overview of the Ortelius 800TM system ( site model) and examination setting.
Figure 2: Scan analysis results. A 2D graphical reconstruction of the patients spine is presented after
examination of the patient with Ortelius 800TM. Location of deformity angle identified and deformity angle
is calculated automatically by the system with an option for manual measurements of any angle between
any other chosen vertebrae.
measurements
on
anterioposterior
radiographs by Pearsons correlation
coefficient. These 18 patients were a
consecutive series of patients and were
randomly chosen. Ortelius 800TM was
employed to calculate the deformity angle
directly on the radiograph and was
compared to Cobb angle measurements as
well. Pearsons correlation coefficient
between Cobb angle and Ortelius 800TM
deformity angle was 0.91 for direct
measurements on the radiograph with
Ortelius 800TM and 0.79 for patient
examination with Ortelius 800TM
(see
table 1 below).
Mean Difference
(degrees)
0.91
0.22
0.79
3.64
Table 1. Comparison of Ortelius 800 TM deformity angles to Cobb angles by Pearsons correlation coefficient (r).
Figure 3: Ortelius 800TM deformity angle analysis of mild deformities. (a)Posterio-anterior spinal
radiograph of a patient with a major right thoracic curvature of 19. Ortelius 800TM graphic representation
of the scoliosis curvature of this patient is overlaid on the posterio-anterior spinal radiograph demonstrating
a deformity angle of 16 degrees as indicated above. (b) Posterio-anterior spinal radiograph of a patient with
left lumbar curvature of 11 degrees. Ortelius 800TM graphic representation of the scoliosis curvature of
this patient is overlaid on the posterio-anterior spinal radiograph demonstrating a left lumbar curve of 11
degrees as indicated above.
Figure 4: Ortelius 800TM angle analysis of moderate deformities. (a)Posterio-anterior spinal radiograph of a patient
with a right lumbar curvature of 25 degrees. Ortelius 800TM graphic representation of the scoliosis curvature of this
patient is overlaid on the posterio-anterior spinal radiograph demonstrating a right lumbar deformity angle of 25
degrees as indicated above. (b) Posterio-anterior spinal radiograph of a patient with right thoracic and left lumbar
curvature of 46 and 32 respectively. Ortelius 800TM graphic representation of the scoliosis curvature of this patient
is overlaid on the posterio-anterior spinal radiograph demonstrating a right thoracic deformity angle of 42 degrees
and a left lumbar curve of 31 degrees as indicated above. (c) Posterio-anterior spinal radiograph of a patient with
right thoracic curvature of 40. Ortelius 800TM graphic representation of the scoliosis curvature of this patient is
overlaid on the posterio-anterior spinal radiograph demonstrating a right thoracic deformity angle of 36 degrees as
indicated above
Conclusion
This is a report of a preliminary study to
investigate the clinical value of Ortelius
800 TM for the diagnosis and monitoring of
scoliosis in a wide range of deformity
angles (ranging from 10-46 degrees). The
preliminary results reveal promising results
regarding both the deformity angle as well
as the spine contour reconstructed by
Ortelius 800 TM as compared to standard
posterioanterior radiographs. A large-scale
study, presently in progress, will allow
further validation of Ortelius 800 TM as a
tool for diagnosis and monitoring of spinal
deformities, as well as further establishment
and reduction of error margins.
References
Cobb JR Outline for the study of scoliosis. AAOS
Instructional Course Lecture 1948;5:26175.
Dickson RA. Scoliosis: how big are you?
Orthopaedics 1987;10:8817.
Pruijis JEH, Hageman MAPE, Kessen W, van der
Meer R, van Wieringen JC. Variation in Cobb angle
measurements in scoliosis. Skeletal Radiol
1994;23:51720.