Clinical Comparisons of the Anatomical Reconstruction and Modified Biceps Rerouting Technique for Chronic Posterolateral Instability Combined with Posterior Cruciate Ligament Reconstruction

Background: The purpose of this study was to describe a one-stage operation for posterior cruciate ligament reconstruction with use of an Achilles tendon-bone allograft and a posterolateral corner reconstruction with use of two different methods, with a comparison of clinical outcomes in the two groups. Methods: Our study included forty-six patients who had undergone posterior cruciate ligament reconstruction with use of an Achilles tendon-bone allograft and posterolateral corner reconstruction with either anatomical reconstruction of the lateral collateral ligament and popliteus tendon with use of a tibialis posterior tendon allograft (twenty-one patients; Group A) or the modified biceps rerouting tenodesis (twenty-five patients; Group B) in an alternating fashion. Patients were assessed for knee instability with use of the dial test at 30 degrees and 90 degrees, together with varus and posterior stress radiography. Results: At the two-year follow-up evaluation, although no significant difference was found on posterior stress radiography (mean and standard error, 5.7 +/- 0.4 mm for Group A compared with 4.8 +/- 0.4 mm for Group B), Group A showed more improvement than Group B on the dial test (16 degrees +/- 1 degrees vs. 13 degrees +/- 1 degrees at 30 degrees and 17 degrees +/- 1 degrees vs. 14 degrees +/- 1 degrees at 90 degrees; p = 0.001 for both) and varus stress radiography (3.6 +/- 0.3 mm vs. 2.6 +/- 0.3 mm; p = 0.024), in the Lysholm (29.5 +/- 2.4 vs. 22.3 +/- 2.3; p = 0.037) and the International Knee Documentation Committee knee scores (p = 0.041), and less terminal flexion loss (4.0 degrees +/- 1.2 degrees vs. 8.8 degrees +/- 1.3 degrees; p = 0.013). Conclusions: Combined with posterior cruciate ligament reconstruction, anatomical posterolateral corner reconstruction of the popliteus tendon and lateral collateral ligament showed better outcomes compared with the modified biceps rerouting tenodesis, although the mean differences of varus and external rotatory stability between the groups were relatively small. However, the overall difference might have been reduced by the negative value caused by overcorrection in Group B. This study demonstrated that anatomical posterolateral corner reconstruction is a reliable alternative method in addressing posterolateral corner and posterior cruciate ligament insufficiency of the knee, a finding that ideally should be tested in a randomized controlled trial.