Purpose: To evaluate the clinical outcome and the incidence of degenerative changes in 25 patients with 25 knees undergoing surgical reconstruction for combined posterior cruciate ligament (PCL) and posterolateral instabilities of the knee with 2-5-year follow-up.
Materials and methods: This series included 16 men and 9 women with an average age of 28 years. The average time from injury to surgery was 10 (range 2-24) months, and the average follow-up time was 40 (range 32-60) months. The mechanisms of injury were 88% due to trauma, and 12% sports related. Arthroscopic single bundle posterior cruciate reconstruction and reconstruction of the posterolateral structures were performed in all cases. Clinical evaluations included functional assessment, ligament laxity and radiograph of the knee. The results were correlated with the duration of injury, the severity of ligament laxity and the follow-up time.
Results: The overall results were 68% satisfactory (28% excellent and 40% good) and 32% unsatisfactory (20% fair and 12% poor). Despite functional improvement, complete restoration of ligament stability was observed in only 44% of the knees, while 36% of the knees showed mild (<5 mm), and 20% moderate (5-10 mm) ligament laxity. There was no correlation of the clinical outcome with the duration from injury to surgery. The incidence of degenerative changes of the affected knee was 44%, and the rate correlated with the severity of ligament laxity, the duration from injury to surgery and the length of follow-up time.
Conclusion: Despite the functional improvement, the currently devised surgical techniques only have modest success in restoration of ligament stability in knees with combined PCL and posterolateral instabilities. Further improvement in surgical technique including a dynamic reconstruction of the popliteus tendon complex seems necessary. The rate of degenerative changes of the affected knee appeared proportional to the duration of injury, the severity of ligament laxity and the length of follow-up time. The results of this study led us to recommend early surgical reconstruction for knees with combined posterior cruciate and posterolateral instabilities.