ABSTRACT
Patellar dislocations are classified as lateral, medial, intraarticular and superior, depending on the direction of dislocation, which depends on the mechanism of the injury. Lateral dislocation is the most common, with other types seen only rarely. Lateral dislocation occurs with forced internal rotation of the femur on an externally rotated and planted tibia with the knee in flexion. Medial instability is rare and usually iatrogenic, congenital, traumatic or associated with atrophy of the quadriceps musculature.1 Superior dislocation usually occurs in elderly individuals from forced hyperextension injuries to the knee with the patella locked on an anterior femoral osteophyte.
