Lower Patient-Reported Outcomes After Isolated Anterior Cruciate Ligament Reconstruction Are Associated With Lower Muscle Strength Rather Than Graft Status During Second-Look Arthroscopic Evaluation.

Abstract

To determine the relationship between patient-reported outcomes (PROs), objective graft status on second-look arthroscopy, and knee muscle strength during the early period after isolated primary anterior cruciate ligament reconstruction (ACLR). Patients who underwent second-look arthroscopy at least 1 year after primary ACLR between 2012 and 2020 were retrospectively reviewed. Those who completed follow-up muscle strength tests and PRO measures were included in this study. Subjective clinical outcomes were assessed on the basis of patient-reported outcome measures using the Lysholm score preoperatively and during second-look arthroscopy. Objective graft status was assessed during second-look arthroscopy using a numeric scale system consisting of the following 4 subscales: tension, vascularity, synovialization, and continuity of the graft. The graft score (0-8) was determined by adding the points from each subscale (0-2). Muscle strength was measured using isokinetic dynamometry to assess peak torque, limb symmetry index for both the quadriceps and hamstrings and the ratio of the hamstring and quadriceps before second-look arthroscopy. Second-look arthroscopy patients included in analysis were those without concomitant meniscal or cartilage procedures. Multivariate logistic regression was used to identify factors associated with inferior PROs (Lysholm score ≤83). A total of 82 patients were enrolled in this study. At an average follow-up of 22.4 ± 4.8 months, 25 patients (30.5%) scored less than 83 on the Lysholm scale. No significant differences were found in total graft status scores between groups with superior or inferior outcomes (6.9 ± 1.8 vs 7.1 ± 1.2, P = .573). However, the group with inferior PROs showed significantly lower peak torque in both hamstring and quadriceps (P = .001 and P < .001, respectively). Multivariate analysis indicated that older age and lower limb symmetry index for extension and flexion (<70% and 90%, respectively) were significantly correlated with inferior PROs (odds ratios: 1.08, 5.11, and 5.66; P = .014, .013, and .006, respectively). Early inferior subjective outcomes after ACLR were associated with delayed recovery of quadriceps and hamstring muscle strength compared to graft appearance and tension. Level III, retrospective comparative case series.