Pattern of Strength Recovery Differences Exist in Adolescent Athletes after Anterior Cruciate Ligament Reconstruction when using Quadriceps Versus Hamstring Tendon Autograft

To compare the timeline for post-operative quadriceps and hamstrings strength recovery following anterior cruciate ligament reconstruction (ACLR) using either a quadriceps tendon (QT) or hamstring tendon (HT) autograft. Patients (≤18 years) who underwent ACLR using autograft QT or HT were included. Isokinetic strength was extracted at 3, 6, and 12 months post-operatively. Effects of time and graft type on quadriceps or hamstring limb symmetry index (qLSI / hLSI) was assessed with two-way repeated measures ANOVA. Between group differences at each time point were assessed with unpaired t-tests. Chi-square and Kaplan-Meir analysis analyzed the proportions of subjects able to achieve ≥90% LSI. A total of 75 subjects (QT n=38 HT n=37,15.8 years) were included. There were significant differences in qLSI, with greater symmetry within the HT group at all time points. A higher proportion of subjects with HT grafts were able to achieve ≥90% qLSI within 12 months of surgery (81% vs 45%, p=0.001). Compared to those with HT autografts, adolescents with QT autografts demonstrate a prolonged timeline for quadriceps recovery. While mean strength values above 90% are achieved, a significantly lower percentage of QT patients are able to achieve 90% qLSI by 12 months post-op.