Acute posterior cruciate ligament injuries.

One hundred and two posterior cruciate ligament injuries were reviewed (43 chronic and 59 acute repairs). The 59 acute repairs were profiled as to cause and site of injury, associated ligamentous damage, clinical examination, patient position at surgery, and reoperation rate. Twenty-two patients were followed up. Motor vehicle accidents and athletics were the usual causes of injury. In the 59 acute repairs, the posterior cruciate avulsion site was femoral in 21, midsubstance in 13, and tibial in 25. The high incidence of associated injuries included medial collateral ligament tears, capsular damage, lateral knee component damage, and anterior cruciate ligament ruptures. Thirteen of 59, believed to have isolated tears, had surgery in the prone position. Twelve were subsequently reoperated. Eight of 12 reoperations were done prone initially for an "isolated" tear. Our acute knees with poor results all had the most supposed "isolated" and midsubstance tears, and the most popliteal surgery. The posterior cruciate ligament tear is due to major violence with associated ligament injuries and has no single universal physical sign. Arthroscopy and examination under anesthesia are recommended to prevent the missed diagnosis (chronic case) or to clarify a suspected "isolated" tear prior to prone popliteal surgery.