Patella examination

The examination of the patella involves:

• placing the knees flexed over the edge of the couch, which may show a torsional deformity of the femur and tibia, or a laterally placed patella
• determining whether the patella is high-lying - patella alta - which predisposes to lateral dislocation
• feeling the anterior surface: - a tender, bi-partate ridge may be present - upper and lower pole tenderness occurs in Sinding Larsen-Johannson disease and with "jumper's knee"
• displacing the patella medially and laterally to feel its articular surface
• moving the patella up, down, laterally and into the knee joint - reduced mobility is characteristic of retro-patella arthritis
• the patella apprehension test