Many failures of anterior cruciate ligament (ACL) reconstruction are due to a failure to treat concomitant posterolateral rotatory instability (PLRI). We report the results of reconstruction in cases of combined PLRI and ACL injury.

From January 1998 to December 2002, 24 patients were followed-up for a mean of 25 months (range, 12 to 58), postoperatively. PLRI was treated using a biceps tenodesis or posterolateral corner sling (PLCS), through a proximal tibial or fibular head obliquely anteroinferiorly to posterosuperiorly. ACLs were reconstructed using autogenous hamstring 4 bundles with RIGIDfix™ on the femoral side and Intrafix™ with additional staple fixation on the tibial side. Clinical results were evaluated using the Orthopadishe Arbeitsgruppe Knie (OAK) and International Knee Documentation Committee (IKDC) knee scoring system. Stability was measured on pull varus stress radiographs using a Telos stress device and by using the manual maximum displacement test using a KT-1000™ arthrometer with 30 ° of knee flexion.

The mean side-to-side difference in anterior displacement measured on the pull stress radiographs was reduced from a preoperative 7.9±3.4 to 2.1±0.8 mm at the last follow-up, from 2.1±0.8 to 0.4±0.7mm on varus stress radiographs, and from 6.5±1.3 mm to 2.3±1.3 mm as measured using the KT-1000 arthrometer. The average OAK score improved from 64.1±11.9 to 84.4±9.2 points over the same period. At the final evaluation, 22 of the 24 patients (92%) had a satisfactory result according to the IKDC system.

Based on our experience, we recommend arthroscopically assisted ACL reconstruction and the correction of concomitant PLRI in cases of combined ACL and posterolateral rotatory instability.