AN18.1-7 | Knee joint, Anterior compartment of leg & dorsum of foot — Glossary

The largest and most complex joint in the body, a modified hinge (condylar) joint allowing flexion, extension, and some rotation

An intracapsular ligament from anterior tibia to lateral femoral condyle that prevents anterior tibial translation; tested by Lachman test

An intracapsular ligament from posterior tibia to medial femoral condyle that prevents posterior tibial translation

An extracapsular ligament attached to the medial meniscus, resisting valgus stress; part of the unhappy triad

An extracapsular ligament NOT attached to the lateral meniscus, resisting varus stress

A C-shaped fibrocartilage on the medial tibial plateau, attached to MCL and less mobile, making it more susceptible to tears

An O-shaped fibrocartilage on the lateral tibial plateau, more mobile than medial meniscus and less commonly torn

Combined injury of MCL, medial meniscus, and ACL from a lateral blow to the knee, common in contact sports

Inability to dorsiflex the foot due to deep peroneal or common peroneal nerve injury, causing steppage gait

The motor nerve supplying all four anterior compartment muscles; injury causes foot drop and sensory loss in the first web space

A branch of the popliteal artery passing through the interosseous membrane to supply the anterior leg, becoming dorsalis pedis at the ankle

The continuation of the anterior tibial artery on the dorsum of the foot, palpable between EHL and EDL tendons

A surgical emergency where raised pressure in the closed anterior compartment compresses nerves and vessels, requiring emergency fasciotomy

The physiological locking of the knee in full extension by lateral rotation of the tibia on the femur

A muscle that unlocks the knee by internally rotating the tibia on the femur, initiating flexion from the locked extended position

The most extensive recess of the knee joint synovial membrane, extending above the patella under the quadriceps tendon

The most sensitive clinical test for ACL integrity, performed with the knee at 20-30 degrees flexion

A clinical test for meniscal tears performed by rotating the tibia on the flexed knee, looking for a palpable click or pain

The most common joint disease in India, characterised by loss of joint space, osteophytes, subchondral sclerosis and cysts

Bow-legs with outward tibial curvature causing increased medial compartment loading and medial osteoarthritis

Knock-knees with inward knee angulation causing increased lateral compartment loading

A compensatory gait pattern in foot drop where the patient lifts the knee high to clear the dragging toes

Emergency surgical release of the fascial compartment to relieve pressure in compartment syndrome, preventing permanent muscle and nerve damage