Anterior Cruciate Ligament Reconstruction: A Comparative Clinical Study Between Adjustable and Fixed Length Suspension Devices.

Background Adjustable-length cortical suspension devices provide technical advantages over fixed-length devices for femoral graft fixation during anterior cruciate ligament (ACL) reconstruction but have shown increased lengthening during cyclic loading in biomechanical studies. The purpose of this study was to prospectively measure graft elongation in vivo along with patient reported outcomes. Methods Thirty-seven skeletally mature patients diagnosed with anterior cruciate insufficiency who underwent ACL reconstruction using autogenous hamstring graft were included in this study. Thirteen patients received an ACL reconstruction using a fixed loop device (FL) and twenty-four patients were treated with an adjustable-length device (AL) based on surgeon preference. Bilateral knee laxity was measured with a KT1000 Arthrometer before surgery and immediately after surgery with the patient under anesthesia, and at the 6-week, 3-month, and 6-month clinical follow-up appointments. All measurements were made by the same operator with maximum force testing. Differences between the affected knee and the contralateral knee were measured. Patient reported outcomes were collected at 6 and 24 months post-operatively. Results No difference was found between the FL and AL groups in either knee laxity or patient reported outcomes. Average side-to-side difference at 6 months was 1.8 ± 2.6 mm for the FL group and 1.7 ± 2.4 mm for the AL group (p=.874). One patient in the FL group (7.7%) and two in the AL group (9.5%) had a side to side difference in laxity greater 5 mm. Patient reported outcomes did not differ between groups and no patients underwent revision surgery. Conclusions The adjustable-length cortical suspension device (AL) did not demonstrate increased laxity as compared to fixed-length devices. There was no difference in patient reported outcomes between the groups.Level of Evidence: IV.