Poor functional outcome in patients with Voluntary knee instability following Anterior cruciate ligament reconstruction

Backgroud Anterior cruciate ligament reconstruction (ACLR) remains the gold standard treatment for anterior cruciate ligament (ACL) injury. However, a good functional outcome even after a successful surgery depends on multiple factors. It has been observed that certain patients with a chronic ACL injury demonstrate knee instability voluntarily. The authors observed that these patients might not perform well even after a successful surgery. This study aims to assess the outcome after ACL and other ligament reconstruction in patients with voluntary knee instability. Methods From a total of 824 patients who underwent ACLR, 13 patients with a history of voluntary knee instability were selected, and data of these patients (demographic and clinical profile) were obtained. Outcomes of surgery in this group of patients were evaluated by using Lysholm score and Tegner activity level. Results All patients were young men with a chronic ACL injury and manifested instability. Associated injuries were lateral meniscus tear in 3 patients, medial meniscus tear in 2, and posterolateral corner (PLC) injury in 3. ACLR was done using the semitendinosus-gracilis graft in all patients. Further, anterolateral ligament reconstruction was done in 2 patients and PLC reconstruction, in 3 patients. The mean Lysholm score was 54.76 (range, 48-62) preoperatively and 60.92 (range, 54-78) at a mean follow-up of 14.3 months (range, 11-26 months). The median Tegner activity level was 6 (range, 5-7) before injury and 4 (range, 3-5) at the final follow-up. Twelve of the 13 patients were able to demonstrate instability voluntarily at the time of the final follow-up. Conclusions In patients with ACL and other ligament injuries who demonstrated voluntary knee instability, the functional outcome even after successful ligament reconstruction was poor.