Atlas of Human Anatomy by Netter

FACTS & HINTS

HIGH-YIELD FACTS

Clinical Points

Baker's Cyst

Posterior herniation of the synovial membrane through the joint capsule into the popliteal fossa

Swelling appears below joint line and may extend as far as the midcalf

Large swellings may interfere with knee movements but otherwise asymptomatic

Bursitis

Inflammation of the bursa surrounding the knee because of repeated frictional forces

In chronic inflammation, bursae become distended and filled with fluid

Prepatellar bursitis (housemaid's knee) and infrapatellar bursitis (clergyman's knee) are most recognized variants

Knee Injury

Knee injuries common, as the knee joint has little external supportive tissue

Ligament sprains usually self-limiting, but may cause secondary damage to menisci

Tearing of the ligaments often needs surgical correction

Rupture of anterior cruciate ligament occurs when force is directed anteriorly to the semi-flexed knee, typically occurring in skiers and

footballers

Posterior cruciate ligament is more resilient to injury, but may rupture when force is applied to the tibial tuberosity while the knee is flexed

Collateral ligaments are vulnerable to lateral stresses

MNEMONICS

Memory Aids

Knock-knee and Bowleg: Genu valgum vs. Genu vargum

Knock-knee: Genu valgum

Genu valGUM-knees are GUMmed together

Bowleg: Genu vargum

Genu VARgum-VAR rhymes with far-knees are VAR (far) apart