Clinical and Radiological Outcomes After Hamstring Anterior Cruciate Ligament Reconstructions: Comparison Between Fixed-Loop and Adjustable-Loop Cortical Suspension Devices

Abstract

Background: Few studies have compared clinical and radiological outcomes after hamstring anterior cruciate ligament (ACL) reconstruction with fixed-loop and adjustable-loop cortical suspension devices. Purpose/Hypothesis: The purpose of this retrospective study was to compare clinical outcomes and tunnel widening after hamstring ACL reconstructions with fixed- and adjustable-loop cortical suspension devices. The hypothesis was that compared with femoral graft fixation with the fixed-loop device, fixation with the adjustable-loop device would show similar clinical outcomes and would result in less tunnel widening after hamstring ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 117 consecutive patients underwent hamstring ACL reconstruction at a single institution. The fixed-loop cortical suspension device was used in 67 patients, and the adjustable-loop cortical suspension device was used in 50 patients. All patients were observed for a minimum of 2 years. Postoperative knee laxity was evaluated with the Lachman test, pivot-shift test, and KT-1000 arthrometer. Functional evaluations were performed by use of the Lysholm score and the Tegner activity scale. On anteroposterior (AP) and lateral radiographs, the measured diameters of the femoral tunnel at 1 year after surgery were compared with the diameter of the reamer used at surgery. The measured diameters of the tibial tunnel at 1 year after surgery were compared with those taken immediately after surgery. Results: The mean KT-1000 arthrometer laxity measurement was 1.5 ± 1.8 mm in the fixed-loop group and 1.2 ± 2.3 mm in the adjustable-loop group ( P = .530). Results of postoperative knee laxity evaluations and functional outcomes from both groups showed no statistically significant differences. However, the fixed-loop group showed significantly better stability in the pivot-shift test than did the adjustable-loop group ( P = .018). On AP radiographs, the mean diameter of the femoral and tibial tunnels increased by 42.2% ± 15.9% and 37.0% ± 17.8%, respectively, in the fixed-loop group and by 43.0% ± 15.4% and 36.8% ± 18.2% in the adjustable-loop group. On lateral radiographs, the mean diameter of the femoral and tibial tunnels increased by 38.1% ± 14.8% and 39.9% ± 13.8%, respectively, in the fixed-loop group and by 35.8% ± 12.2% and 38.1% ± 21.0% in the adjustable-loop group. No significant differences were found between the 2 groups in postoperative femoral and tibial tunnel widening on AP radiographs ( P = .801 and .951, respectively) or lateral radiographs ( P = .422 and .621, respectively). Conclusion: Compared with femoral fixation by use of the fixed-loop device, femoral fixation by use of the adjustable-loop device showed similar clinical outcomes but did not reduce tunnel widening after hamstring ACL reconstructions.