Objective: Many have advocated the importance of correcting posterolateral rotatory instability (PLRI) in injuries causing rupture of the posterior cruciate ligament and PLRI. However, there have been few studies comparing the results of reconstructing the posterior cruciate ligament (PCL) in isolation with PCL reconstruction combined with stabilisation of the posterolateral corner. We set up a retrospective study to directly compare the results of an isolated PCL reconstruction with a combined PCL reconstruction and Larsen tenodesis.

Methods: Seventeen consecutive patients with symptoms of instability and chronic rupture of the PCL and PLS were identified from our database. There were 1 1 men and 6 women. Ten patients were injured while playing sport, six in road traffic accidents, and one was a result of a fall. The mean age of the patients at the time of surgery was 31 (range 21–47), and the interval from injury to surgery was a mean of 23 months (months–10 years). The mean follow up was 35 months (14–74 months). All patients had unstable knees, with significant posterolateral rotatory instability. In 12 cases the PCL alone was reconstructed, in 5 cases a combined posterior cruciate ligament and posterolateral corner reconstruction was performed. Prior to surgery all patients underwent a physical examination of both knees. Posterior draw, posterior sag and reverse Lachman tests were used to assess PCL function. Posterolateral rotatory instability was assessed by the dial test. Plain radiographs and either an M [RI or arthroscopy of the affected knee were performed. At follow-up patients underwent examination of both their knees. A subjective assessments of function was made using the Tegner, and Lysholm scoring systems

Results: At a mean follow up of 35 months, both groups had significantly improved compared to their preoperative status, as measured by Lysholm and Tegner scores and posterior draw test (P< 0.01). The group in which only the PCL was reconstructed had significantly lower scores compared to those who had the additional posterolateral corner reconstruction (Tegner P< 0.04, Lysholm P< 0.02).

Conclusion: The results of PCL reconstruction were significantly improved when combined with a Larsen tenodesis in patients with severe posterolateral rotatory instability.