This paper describes a new anatomic reconstructive surgical procedure that simultaneously reconstructs the fibular collateral ligament, popliteal tendon and popliteofibular ligament using a split Achilles allograft and compares the clinical results of this new technique with the posterolateral corner sling procedure used for posterolateral instability of the knee.

Forty-six patients were treated for a posterolateral instability of the knee between 1998 and 2003. The posterolateral corner sling procedure (Group A) was performed in 25 patients and anatomic reconstructive surgery (Group B) in 21 patients. The minimum follow-up was 12 months. An arthroscopic evaluation was performed in all cases. The clinical review included the Lysholm knee scores as well as a lateral instability and tibial external rotation assessment.

The mean Lysholm knee scores in groups A and B were 54.8 points and 54.4 points prior to surgery, and 86.9 and 93.6 points at the time of the latest follow-up, respectively (p<0.05). Tibial external rotation of 5 ° more than the contralateral uninjured knee was noted in 12% of group A and in 5% of group B (p<0.05). Lateral instability of 5 mm greater than the contralateral knee was observed in 28% of group A and in 14% of group B (p<0.05).

Anatomic reconstruction of the posterolateral corner resulted in less lateral instability and tibial external rotation than did the posterolateral corner sling procedure.