Anterior Cruciate Ligament Graft Tensioning in Full Extension

Abstract

The purpose of this study was to determine anterior laxity and graft forces in cadaveric knees after anterior cruciate ligament reconstruction in which the graft is tensioned with the knee in full extension. We also ana lyzed the clinical results from a series of patients who had ligament reconstructions using this technique. We performed anterior cruciate ligament reconstructions on seven fresh cadaveric knees and then measured the anterior laxity, graft set force, and graft tension. We also did a prospective minimum 2-year followup on 57 pa tients who underwent anterior cruciate ligament recon struction. The in vitro data showed average anterior lax ity of 1.1 mm greater than the intact knee with an 89-N anterior force at 30° of knee flexion. Average graft set force was 68 N, and graft tension in extension was 18 N. In the clinical portion of the study, knee laxity improved from 7.5 to 0.8 mm (side-to-side difference at 89 N). The patients' Lysholm and Tegner scores improved from 65 to 90 and 3.9 to 5.6, respectively. Only one patient had a postoperative contracture. The results of this study suggest that graft tensioning in full extension provides a low incidence of flexion deformity, maintaining excel lent functional results and satisfactory biomechanics.