The purpose of this article is to evaluate the incidence of posterior
cruciate ligament (PCL) injuries in trauma patients with acute hemarth
rosis of the knee. Sixty-one acute knee injuries underwent examination
under anesthesia and diagnostic arthroscopy at a tertiary care trauma
center over an 11-month period. PCL injuries occurred in 44% (27 of 6
1) acute knee injuries; 81.5% (22 of 27) were trauma patients and 18.5
% (five of 27) were sports related. Higher energy mechanisms of injury
may account for the difference. Isolated PCL injuries were rare [7.5%
(two of 27)], whereas 92.5% (25 of 27) of PCL injuries occurred in co
mbination with other ligament injuries. Trauma patients have a higher
incidence of PCL injuries than does the athletic population. Acute kne
e hemarthrosis in trauma patients should elevate suspicion for PCL inj
uries. Arthroscopy is a valuable tool for PCL evaluation and surgical
planning.