Comparison of Dynamic Postural Stability in Autografts Versus Allografts Following Anterior Cruciate Ligament Reconstruction With Remnant Preservation: A Prospective Study With 1-Year Follow-up.

Background: Graft selection is an important part of preoperative planning for anterior cruciate ligament reconstruction (ACLR). In addition, ACLR with the 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.

Purpose: To compare knee muscle strength, neuromuscular control, and patient-reported outcomes between hamstring (HS) tendon autografts and tibialis anterior (TA) allografts in patients undergoing ACLR with remnant preservation through posterior transseptal portal for >1 year.

Study design: Cohort study; Level of evidence, 3.

Methods: A total of 70 patients who underwent ACLR with remnant preservation between 2018 and 2021 using HS tendon autograft (n = 35) or TA allograft (n = 35) were analyzed at 3 different time points (preoperative, 6 months, and 12 months). Quadriceps and HS muscle strengths were measured with an isokinetic device. Proprioception was evaluated with reproduction of passive positioning for joint position sense and overall stability index (OSI) for dynamic postural stability. Patient-reported outcomes included the Lysholm score and the International Knee Documentation Committee score.

Results: There were no significant differences in demographic information including age, body mass index, concomitant meniscal injuries, and sports activities (P > .05) between HS tendon autograft and TA allograft groups. Quadriceps and HS strength in both groups, HS strength in deep knee flexion in both groups, and OSI in the HS tendon autograft group significantly improved at 12 months (P < .05). Repeated-measures analysis of variance revealed significant interactions between time and grafts for OSI (F[2, 136] = 5.08; P = .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 HS tendon autograft group (2.1 ± 0.8) at 12 months (P = .009), indicating better dynamic postural stability in the HS tendon autograft group.

Conclusion: No significant differences were found in knee muscle strength or patient-reported outcomes between HS tendon autograft and TA allograft after ACLR with remnant preservation for up to 1 year except for dynamic postural stability favoring HS tendon autograft.