Anterior cruciate ligament reconstruction in partial tear: selective anteromedial bundle reconstruction conserving the posterolateral remnant versus single-bundle anatomic ACL reconstruction: preliminary 1-year results of a prospective randomized study

Abstract

Introduction: Partial tears of the anterior cruciate ligament (ACL) are frequent. Conserving ACL remnants is central to the concept of anatomic, biomechanical and biological reconstruction. The interest of such conservation remains theoretical. The present hypothesis was that selective anteromedial (AM) bundle reconstruction is preferable to the standard single-bundle reconstruction in partial ACL tear.

Materials and methods: A multicenter prospective randomized study recruited 54 partial ACL tears operated on either by selective AM bundle reconstruction (Group 1, n=29) or by standard anatomic single-bundle reconstruction (Group 2, n=25). All patients were clinically assessed on subjective and objective IKDC, Lysholm and KOOS scores, with a minimum 12 months' follow-up. Comparative pre- to postoperative anterior laxity was measured on the Rolimeter(®) device, with statistical analysis of results.

Results: There were no significant preoperative differences between the two groups. All patients were followed-up at 6 months and 1 year. Mean subjective IKDC scores for groups 1 and 2 respectively were 55.8 and 56.8 preoperatively versus 86.2 and 85.7 at 1 year; Lysholm scores were 69.9 and 71.1 versus 90.9 and 91.8. These inter-group differences were non-significant. Differential laxity for groups 1 and 2 respectively was 5.0mm (range, 2-10) and 5.1mm (2-12) preoperatively (P=0.73), versus 1.2mm and 1.9 mm postoperatively (P=0.03).

Discussion and conclusion: In partial ACL tear, selective AM bundle reconstruction conserving the posterolateral bundle remnant provides clinical results comparable to the standard single-bundle technique, with better control of anterior laxity. Longer follow-up, however, will be needed to compare evolution in anterior and rotational laxity and in subjective results over time.