The influence of popliteus tendon reconstruction on the external rotation instability on patients with anterior cruciate ligament and posterolateral injury

Background: Various surgical techniques to treat posterolateral corner (PLC) injuries have been described. The purpose of this study was to evaluate the influence of popliteus tendon (PT) reconstruction on anterior cruciate ligament (ACL) reconstruction in terms of external rotation laxity and clinical outcomes with tibialis anterior allograft. Methods: Between September 2005 and December 2008, 32 consecutive patients with combined ACL and PLC injuries who underwent the combined ACL-PT reconstruction with tibialis anterior allograft were studied retrospectively. The authors randomly selected 50 patients who underwent isolated ACL reconstruction during the same operative period as the control group. Clinical outcomes were determined from data obtained before surgery and at the last follow-up examination. Result: Postoperatively, mean anterior translation (side-to-side difference) was reduced from 6.8 +/- 1.2 mm to 2.0 +/- 0.8 mm in study group and from 6.1 +/- 1.7 mm to 1.7 +/- 0.5 mm. In study group, the dial test at 30 degrees and 90 degrees of knee flexion had significantly decreased from 16.0 degrees +/- 2.3 degrees to 4.6 degrees +/- 2.1 degrees and from 12.7 degrees +/- 2.3 degrees to 3.8 degrees +/- 2.3 degrees at the last follow-up. These differences were statistically significant. With regard to Lysholm and Tegner activity scores, both groups showed statistically improvements at the last follow-up. The IKDC subjective knee evaluation score was 56.2 +/- 11.3 preoperatively and 86.3 +/- 10.1 postoperatively in study group and 58.6 +/- 12.3 preoperatively and 88.6 +/- 12.3 postoperatively in control group. At the last follow-up, 29 patients (90.6%) in the study group and 46 patients (92.0%) in the control group had an IKDC knee classification of A or B. Conclusions: The results of combined ACL-PT reconstruction showed as excellent as the isolated ACL reconstruction. Furthermore, the results of the medium-term study indicate that both anteroposterior and external rotation laxity could be improved by combined ACL-PT reconstruction.