Summary

Hamstring-autografts were associated with better dynamic postural stability than Tibialis anterior-allografts in the operated knees.

Abstract

Graft selection is an important part of the pre-operative planning for anterior cruciate ligament reconstruction (ACLR). In addition, ACLR with remnant preservation technique has recently gained attention due to potential benefit in bone-tendon healing, graft revascularization, and proprioceptive nerve remodeling. However, the ideal graft choice remains controversial, and there is limited research comparing autograft and allograft in ACLR with remnant preservation. The purpose of this study was to compare knee muscle strength, neuromuscular control, and patient-reported outcomes between hamstring autografts (H-autografts) and tibialis anterior allografts (TA-allografts) in patients undergoing ACLR with remnant preservation through posterior trans-septal portal for over 1 year. A total of 70 patients who underwent ACLR with remnant preservation from 2018 to 2021 using H-autograft (n = 35) or TA-allograft (n = 35) were analyzed at three different time points (pre-operative, 6 months, and 12 months). Quadriceps and hamstring muscle strengths were measured with an isokinetic dynamometer. Proprioception was evaluated with reproduction of passive positioning (RPR) for joint position sense and overall stability index (OSI) for dynamic postural stability. Patient-reported outcomes included Lysholm score and the International Knee Documentation Committee (IKDC) score. There were no significant differences in demographic information including age, body mass index, concomitant meniscal injuries, and sports activities (p > 0.05) between H-autograft and TA-allograft groups. Quadriceps and hamstring strength in both groups, hamstring strength in deep knee flexion in both groups, and OSI in the H-autograft group significantly improved at 12 months (p < 0.05). Repeated-measures ANOVA revealed significant interactions between time and grafts for OSI F [2, 136] = 5.08, p = 0.007. The subsequent independent t-test demonstrated that the OSI was significantly higher in the TA-allograft group (2.7 ± 1.0) than that of the H-autograft group (2.1 ± 0.8) at 12 months (p = 0.009), indicating better dynamic postural stability in the H-autograft group. Therefore, no significant differences were found in knee muscle strength or patient-reported outcomes between H-autograft and TA-allograft after ACLR with remnant preservation for up to 1 year except for dynamic postural stability favoring H-autograft.