Effects of Initial Graft Tension on Clinical Outcome After Anterior Cruciate Ligament Reconstruction

Abstract

We conducted a prospective, randomized, short-term study to clarify the effects of initial graft tension on clinical outcome after arthroscopically assisted anterior cruciate ligament reconstruction with autogenous dou bled semitendinosus and gracilis tendons connected in series with polyester tapes. Seventy Japanese patients with chronic, "isolated" anterior cruciate ligament tears were entered in the study. The patients were randomly divided into three groups based on initial graft tension: Group 1 (20 N), Group 2 (40 N), or Group 3 (80 N). No statistical differences were noted among the three groups with regard to their background factors. The patients were observed for 2 years or more after sur gery. Postoperatively, the average side-to-side differ ence in anterior laxity was 2.2 ± 2.4 mm in Group 1, 1.4 ± 1.8 mm in Group 2, and 0.6 ± 1.7 mm in Group 3. Analysis of variance testing showed that the post operative laxity in Group 3 was significantly less than that in Group 1. Spearman's rank-order correlation analysis also demonstrated significant correlation be tween the magnitude of initial graft tension and the magnitude of the postoperative laxity. This study dem onstrates that relatively high initial tension (up to 80 N) reduces the postoperative anterior laxity of the knee joint after anterior cruciate ligament reconstruction us ing the doubled autogenous hamstring tendons con nected in series with polyester tapes