[Modified Larson technique for posterolateral corner reconstruction of the knee].

OBJECTIVE: Posterolateral soft-tissue reconstruction to restore knee kinematics in isolated or combined posterolateral instabilities.

INDICATIONS: Isolated or multiligament knee injuries with posterolateral insufficiency (popliteus tendon, lateral collateral ligament [LCL], popliteofibular ligament).

CONTRAINDICATIONS: Arthrofibrosis. Severe varus deformity. Fixed posterior drawer. Doubts about compliance.

SURGICAL TECHNIQUE: Graft harvest of semitendinosus tendon. In cases with multiligament reconstruction or associated posterior cruciate ligament (PCL) reconstruction contralateral graft harvest. Suture at 24 cm with baseball stitches using biodegradable material. Two-incision technique: one over the fibular head, one over the lateral epicondyle. Dissection along the biceps femoris to identify and free the peroneal nerve. Kirschner wire-guided creation of a 4.5-mm tunnel through the fibular head. Longitudinal incision of tensor fasciae latae and Kirschner wire drilling at the insertion of the LCL and the politeus tendon. Isometric testing. Overdrilling with an appropriately sized drill (6-7 mm, depth 40 mm). Graft passage through the fibular head and underneath biceps muscle and tensor fasciae latae into the femoral tunnel. Fixation with a biodegradable interference screw at 70° knee flexion in slight internal rotation.

POSTOPERATIVE MANAGEMENT: Defensive rehabilitation due to associated PCL reconstruction using a Posterior Tibial Support (PTS) brace for 6 weeks (day and night). PCL brace with limited range of motion for the next 6 weeks and PTS brace at night. Rehabilitation in a prone position.

RESULTS: 42 patients (10/2003-10/2006) with posterolateral reconstruction according to Larson. All patients received combined PCL and posterolateral reconstruction. No intraoperative complications, one patient with hematoma in the popliteal fossa (conservative treatment), two patients with hematoma following contralateral graft harvest. At followup after 2.6 years, 40 patients were enrolled showing high improvement according to IKDC (International Knee Documentation Committee) and Lysholm Scores.