Isometric reconstruction of the posterolateral corner of the knee.

To date, there is no consensus on the best technique to repair injured posterolateral structures of the knee. We evaluated the effects of a fibular head based isometric reconstruction of the posterolateral knee corner with a double bundle semitendinosus tendon. From February 2001 to February 2005, 18 isometric reconstructions of a chronic posterolateral corner (PLC) injury of the knee were performed using the semitendinosus tendon. The average age of the patients was 39 years, ranging from 19 to 52 years. Twelve were male and 6 female. The time interval between injury and treatment ranged from 1.5 to 14 months. Three patients had simple PLC injuries, 10 had combined PLC-posterior cruciate ligament (PCL) injuries and two of them had undergone a PCL reconstruction elsewhere 6.5 months prior to referral. Three other patients had an associated anterior cruciate ligament (ACL) injury and two had a combination of PLC with ACL and PCL injury. A doubled semitendinosus tendon was threaded through bony tunnels in the fibular head running from the insertion of the lateral collateral ligament (LCL) to the fibular insertion of the popliteo-fibular ligament and both ends were fixed proximally into bony tunnels of the lateral femoral condyle at their respective isometric point. The varus stress test and the posterolateral rotation test were used to evaluate stability of the posterolateral structures. Isometry was optimal between the femoral attachment site of the popliteal tendon to the anatomical insertion of the popliteofibular ligament at the fibular head. The fibular insertion of the LCL is isometric to the anterior or antero-inferior 8-10 mm of the femoral insertion of the LCL. The average follow-up period was 32 months (30-42 months). There was no varus knee instability in full extension. At 30 degrees of flexion two cases demonstrated a grade I varus instability. A fibular head based isometric reconstruction is a reproducible and reliable technique for reconstruction of the posterolateral corner of the knee.