Traumatic knee dislocations are relatively rare and almost always respond to closed reduction; however, a small percentage of knee dislocations are irreducible and in these cases open reduction is frequently required. A 65-year-old man with an unreduced posterolateral knee dislocation with laterally dislocated patella was seen 3 weeks after a motor vehicle accident. Medial femoral condyle was found buttonholed through the medial capsule together with the medial collateral ligament and lying in the medial joint space that allowed posterior rotary dislocation of the joint. Both cruciate ligaments and medial meniscus were torn. There was no evidence of any vascular or nerve injury. Reduction was accomplished by removal of the capsuloligamentous structures which were incarcerated in the trochlea and intercondylar notch and by excision of meniscal tear. Following posterior cruciate ligament reconstruction with patellar tendon autograft, lateral patellar release, vastus medialis advancement, and gracilis transfer were done. © Urban & Vogel.