Recurrent posterior knee laxity: diagnosis, technical aspects and treatment algorithm.

Purpose: Aim of this study was to determine the characteristics, clinical and radiological diagnostic methods of PCL isolated and combined knee injuries.

Methods: One hundred and twelve patients with a recurrent posterior knee laxity were surgically treated. Clinical examination, MRI, Telos™ stress dynamic X-rays, KT-1000 measurements and the IKDC questionnaire were used to diagnose and evaluate these injuries.

Results: Median follow-up was 4.5 years (2-11 years). Thirty-two patients (28.6 %) had an isolated posterior laxity, 53 (47.3 %) a posterior posterolateral laxity, 21 (18.7 %) a posterior posteromedial laxity and six (5.4 %) patients had a complex posterior and mediolateral laxity. Road traffic accidents and sports injuries were the main causes of trauma. The mean preoperative value of posterior tibial translation was 13.5 mm (SD 1.4) and the mean postoperative value was 4.4 mm (SD 1.7) as measured with the Telos device. In the cases with a concomitant ACL rupture, the mean preoperative value of anterior tibial translation was 6.5 mm (SD 1.3) and the mean postoperative value was 1.7 mm (SD 0.8). The mean pre- and postoperative IKDC scores were 74.5 (SD 4.2) and 87.9 (SD 3.1), respectively. Meniscal and/or cartilage injuries were found in 80 patients (71.4 %).

Conclusions: Recurrent posterior knee laxity can be restored with the one-stage PCL reconstruction using a quadriceps graft and reconstruction of the posteromedial-posterolateral lesions using the LaPrade techniques. The benefits of this study include enabling surgeons to accurately manage these injuries from a clinical perspective, and treating them with a specific surgical algorithm.

Level Of Evidence: III.