The role of arthroscopic surgery in the evaluation of acute traumatic hemarthrosis of the knee.

Eighty patients presented for evaluation with an acute traumatic hemarthrosis of the knee and negligible instability on clinical examination. All had an examination under general anesthesia followed by arthroscopy. Anatomical lesions were demonstrated in 71 of 80 knees (89%) including anterior cruciate ligament (ACL) disruption in 50 (62%). Twenty-nine of 50 patients (58%) with arthroscopically-demonstrated ACL injuries had associated meniscal tears. Fifteen (19%) demonstrated isolated meniscal tears and nine (11%) osteochondral fractures not detected by conventional roentgenograms. The frequent occurrence of injuries to other joint structures in conjunction with ACL injuries was remarkable. An acute traumatic hemarthrosis of the knee often masks significant lesions. Arthroscopy aids the orthopedic surgeon in determining the full extent of the intraarticular damage.