Feline Patellar Luxation Study Guide

Overview and Clinical Importance

Patellar luxation (PL) is the displacement of the patella (kneecap) from its normal position within the trochlear groove of the femur. While less common in cats than dogs, patellar luxation represents an important cause of pelvic limb lameness in feline patients. Unlike dogs, many clinically normal cats have physiological laxity in the patellofemoral joint, making diagnosis more nuanced.

Approximately 80% of cats with patellar luxation have bilateral involvement. Medial patellar luxation (MPL) accounts for approximately 95% of cases in cats, with lateral patellar luxation (LPL) being rare.

Anatomy of the Feline Stifle

The stifle joint (knee) connects the femur to the tibia and fibula. The patella is a sesamoid bone embedded within the quadriceps tendon that articulates with the trochlear groove on the cranial distal femur.