Effects of posterior cruciate ligament resection on the tibiofemoral jointgap

The effect of posterior cruciate ligament resection on the tibiofemoral joi nt gap was analyzed in 30 patients with varus osteoarthritis of the knee wh o underwent total knee replacement. The medial soft tissue was released and the bone cut was made without preserving the bone segment of the tibia to which the posterior cruciate ligament was attached. Then the medial and lat eral joint gaps in full extension and 90 degrees flexion were measured befo re and after the posterior cruciate ligament was resected using a tensionin g device. After the resection, the flexion gap significantly increased in t he medial and the lateral sides (4.8 +/- 0.4 and 4.5 +/- 0.4 mm, respective ly, mean +/- standard error) compared with those seen in the extension gap (0.9 +/- 0.2 and 0.8 +/- 0.2 mm). There was no significant difference betwe en the changes in the medial and lateral gaps. The mean value of the flexio n gap was 2 rum smaller than the extension gap before the resection and 1.7 mm larger after the sacrifice. Overall, posterior cruciate ligament resect ion resulted in an increase in the flexion gap and made space for approxima tely 3-mm thicker polyethylene. The flexion gap can be controlled selective ly with posterior cruciate ligament release.