Anatomic reconstructive surgery for posterolateral instability of the knee

Purpose: We describe an anatomic reconstructive surgical procedure that simultaneously reconstructs the fibular collateral ligament, popliteal tendon, and popliteofibular ligament using split Achilles allograft, and compare the clinical results of this technique with those of the posterolateral corner sling procedure for posterolateral instability of the knee. Type of Study: Case series. Methods: Forty-six patients were treated for posterolateral instability of the knee between 1998 and 2002. The posterolateral corner sling procedure was performed in 25 patients (group A) and anatomic reconstructive surgery in 21 patients (group B). The minimum follow-up was 12 months. In all cases, arthroscopic evaluation was performed. Clinical review included the Lysholm knee scores and varus laxity and tibial external rotation assessment. Results: The mean Lysholm knee scores were 54.8 points in group A and 54.4 points in group B before surgery, and 86.9 and 93.6 points at the time of the latest follow-up, respectively (P < .05). Tibial external rotation of 5 degrees more than the contralateral uninjured knee was present in 12% of group A and in 5% of group B (P < .05). Varus laxity of 5 mm greater than the contralateral knee was observed in 28% of group A and in 14% of group B (P < .05). Conclusions: Anatomic reconstruction of the posterolateral corner resulted in less varus laxity and tibial external rotation than did the posterolateral corner sling procedure. Level of Evidence: Type IV, case series, no or historical control group.