Recurrent subluxation of patella, left knee

This code signifies an unstable left kneecap that repeatedly slips partially out of its normal groove. This condition typically causes pain, swelling, and a feeling of the knee "giving way." It's distinct from a complete dislocation, where the patella fully separates from the trochlear groove.

Apply this code when documentation clearly indicates a history of the left patella repeatedly subluxing. This diagnosis is supported by physician notes detailing recurrent episodes of partial patellar displacement, often accompanied by physical examination findings of patellar instability or positive apprehension tests.

• Ensure the documentation specifies "recurrent" subluxation, not an initial or acute event.
• Verify laterality; this code is specific to the left knee.
• Distinguish from M22.0 (Recurrent dislocation of patella) which implies a complete displacement.