The influence of posterolateral rotatory instability on ACL reconstruction: comparison between isolated ACL reconstruction and ACL reconstruction combined with posterolateral corner reconstruction

Abstract

BACKGROUND: The purpose of the present retrospective study was to evaluate the influence of posterolateral corner reconstruction on anterior cruciate ligament (ACL) reconstruction in terms of anterior laxity and clinical outcomes. We hypothesized that the effects of combined ACL and posterolateral corner reconstruction would be less satisfactory than those of isolated ACL reconstruction in terms of anterior laxity and clinical outcomes.

METHODS: We retrospectively studied sixty-nine patients who underwent ACL reconstruction from February 2001 to December 2005. Forty-six patients underwent isolated ACL reconstruction (Group I), and twenty-three patients underwent combined ACL and posterolateral corner reconstruction (Group II). Clinical outcomes were determined from data obtained before surgery and at the time of the twenty-four-month follow-up examination.

RESULTS: Postoperatively, the mean side-to-side difference (and standard deviation) in anterior tibial translation, measured with a KT2000 arthrometer, was greater for Group I (2.2 ± 1.0 mm) than for Group II (1.6 ± 0.8 mm) (p = 0.031). Seven knees (15.2%) in Group I and two knees (8.7%) in Group II had grade-1 anterior translation. The mean Lysholm score was 93.2 in Group I and 90.1 in Group II (p = 0.392). Thirty-eight knees (82.6%) in Group I and twenty knees (87.0%) in Group II were classified as normal or nearly normal according to the International Knee Documentation Committee scoring system (p = 0.882).

CONCLUSIONS: On the basis of the evaluation of ligamentous laxity with use of the KT2000 arthrometer, we observed that combined ACL and posterolateral corner reconstruction allows less anterior translation than isolated ACL reconstruction. However, we could not identify significant differences between the two groups in terms of functional outcomes.