Lec - 2 - Knee, Ankle & Foot
Lec - 2 - Knee, Ankle & Foot
Lec - 2 - Knee, Ankle & Foot
Dr. Shamay Ng
29 Jan 2018
Department of Rehabilitation Sciences
The Hong Kong Polytechnic University
Bones of Knee Joint
3 articulations:
•Two femoro-tibial
articulations
•One femoro-patellar
articulation
Radiography of Knee Joint
• Movements allowed:
Flexion & extension
Rotation around vertical axis
(limited)
Femoro-tibial Joint
• 2 concave tibial plateaus
Medial meniscus:
semicircular
Lateral meniscus: nearly a
complete ring
Menisci
• Medial
– Attachments:
Peripherally – by coronary
ligament to tibial plateau
Medially – attached to
capsule and MCL
Anterior horn – transverse
ligament
Menisci
• Lateral
– Attachments:
Peripherally – by
coronary ligament to
tibial plateau
Anterior horn –
transverse ligament
Menisci
• Functions:
Shock absorbers
Improving congruency & contact area
During movement:
Rotations: menisci move with femur
Flexion/extension: menisci move with
tibia
Stability: Ligaments
• Collaterals
– Medial
Broad, fan-shaped ligament 10-12cm long
Passes from medial epicondyle anteriorly to the
medial tibia
Superficial and deep portions
Functions:
1. Resists excessive abduction of
tibia on femur
2. Limits anterior translation of
tibia on femur, and
hyperextension
Stability: Ligaments
• Collaterals
– Lateral
Fibrous cord 5-6cms
Lateral epicondyle and directed
posterior to the fibular head
No attachment of menisci
Functions:
1. Resists varus stress during flexion/extension
2. Limits knee hyperextension
Function:
Prevents anterior translation of
tibia on femur
Stability: Ligaments
• Posterior Cruciate
Starts at posterior intercondylar
tibia
Passes superiorly, anteriorly, and
medially
Attaches to inner aspect of medial
femoral condyle
Function:
Resists posterior translation of the
tibia on femur
Patellar
Ligaments that
surface
Stabilize
the Knee Joint
Posterior cruciate
ligament
Lateral Medial
Anterior cruciate
ligament
condyle condyle
Tibial collateral
ligament Menisci
Medial
Fibular collateral
ligament
Tibia Lateral
Cut tendon of
biceps femoris
muscle
Fibula
• Extension:
Quadriceps femoris
• Flexion:
Hamstrings
• Special Function: Unlocking
Popliteus
Locking/Unlocking Mechanism
• Lax structure
Ligaments
Tibia Extracapsular
ligament (patellar)
ligamentous structures
ligament (cruciate)
• Dynamically stabilized by
muscle tendons Knee joint, sagittal section
• Patella
‒ Medial and lateral
facets divided by a
vertical ridge
‒ Odd facet (most
medial aspect)
Patellofemoral Joint
• Stability
Longitudinally:
Quadriceps tendon superiorly
Patella tendon inferiorly
Transversely:
Medial and lateral patellar
retinaculae (indirectly VM & VL)
Patellofemoral Joint
Movement:
Full extension: no contact between
femur & patella
10-90° of flexion both facets in
contact
90-135° gradually less medial facet
contact until only lateral/odd
135°
Arterial Anastomoses Around Knee
• Genicular anastomosis
(genu=knee)
Branches of femoral,
popliteal,
anterior/posterior tibial
arteries
Popliteal Fossa
Arteries of Leg and Foot
Femoral triangle
Popliteal fossa
Short (Small)
Saphenous vein
Ankle and Foot
Bones of the Foot
Phalanges (14)
Tarsal Bones
Ankle joint
• Hinge type of synovial joint
• Proximal
– Distal ends of tibia + fibula +
inferior transverse part of the
posterior tibiofibular ligament
mortise (deep socket)
• Distal
– Trochlea (L. pulley) of the
talus
Fibrous Capsule of Ankle joint
• Fibrous capsule
– Thin anteriorly and posteriorly
– Lateral collateral ligament
• Anterior talofibular ligament
• Posterior talofibular ligament
• Calcaneofibular ligaments
• Subtalar joint
• Talocalcaneonavicular
• Calcaneocuboid
• Cuneonavicular
• Tarsometatarsal
• Intermetatarsal
• Metatarso-phalangeal
• Interphalangeal
Transverse Tarsal Joints
• Subtalar joint
Between talus and calcaneus
Metatarsals 1-5,
Cuneiform 1-3, Cuboid
Longitudinal Arches
Medial:
Lateral:
MT 1-3, Cuneiform 1-3,
MT 4 -5, Cuboid &
Navicular
Calcaneus
Talus & Calcaneus
Mechanisms of Arch Support
• Adductor Hallucis*
• Quadratus Plantae
• Abductor digiti
minimi
• Lumbricals (2 lateral)
• Flexor Digiti Minimi
Brevis
• Interossei
Nerves of Foot
•Abductor Hallucis
•FDB
•Lumbricals (2 medial)
•Flexor Hallucis Brevis
Clinical Implications
Unhappy Triad of Knee Injuries
• Inflammation of the
deep bursa of the
calcaneal tendon
• Caused by excessive
friction on the bursa as
the tendon continuously
slides over it
Claw toes
• Hyper extension of the metatarsophalanged joints
• Flexion of the distal interphalangeal joints of lateral 4 toes
• Rigid:
flat with or without weight
• Causes:
injury of the common fibular nerve
Flaccid paralysis of all dorsiflexors
and evertors
Any Questions?