Inadvertent Debridement of the Medial Patellofemoral Ligament Following Arthroscopic Knee Surgery for Infection: A Case Report

INTRODUCTION: Arthroscopic debridement of the knee is usually considered a safe procedure. There are no case reports of medial patellofemoral ligament (MPFL) injury leading to habitual dislocation of the patella following this procedure in the literature. CASE PRESENTATION: A 35-year-old male presented with complaints of habitual dislocation of the left patella, which he noticed after multiple arthroscopic surgeries of the left knee performed elsewhere. He had a history of septic arthritis of the knee following anterior cruciate ligament reconstruction, for which he underwent arthroscopic debridement of the knee twice. After a detailed evaluation, we noticed MPFL medial patellofemoral ligament injury. CONCLUSION: The MPFL medial patellofemoral ligament injury occurred as a result of extensive resection of the medial joint capsule while operating for septic arthritis. This rare grave surgical complication emphasizes the care one should take during arthroscopic debridement of the knee.