ABSTRACT
PURPOSE: The purpose of this study was to confirm the efficacy of arthroscopic findings for the diagnosis of posterolateral rotatory instability (PLRI) of the knee. MATERIALS AND METHODS: We retrospectively evaluated 27 patients (28 cases) who had been operated upon for PLRI between February 1998 and June 2001. All patients underwent preoperative or intraoperative arthroscopic examinations including anterior/posterior cruciate ligament, popliteus tendon, inferior and superior popliteomeniscal fascicle, popliteofibular ligament, lateral meniscus, instability and abnormal popliteomeniscal motion for internal and external rotation. RESULTS: Instability, which means popliteal hiatus widening during internal rotation of the tibia, was identified in all cases (100%). Tear of the inferior and superior popliteomenical fascicle was identified in 24 cases (86%) and abnormal popliteomeniscal motion during rotation was identified in 20 cases (71%). Popliteus tendons were abnormal in 18 cases (65%) with 5 cases (19%) of complete tear and 13 cases (46%) of partial tear or elongation. CONCLUSION: These results suggest that arthroscopic evaluation of the popliteal hiatus structures in the patients suspected for PLRI of the knee is helpful for diagnosis and the determination of treatment modality.