Remnant Preservation Improves 10-Year Graft Survival and Rotational Stability in Anatomic Single-Bundle Hamstring Anterior Cruciate Ligament Reconstruction.

Abstract

To compare clinical outcomes and survival rates of isolated anterior cruciate ligament reconstruction (ACLR) with versus without remnant preservation using hamstring autografts at a minimum 10-year follow-up. We retrospectively reviewed unilateral isolated ACLRs with hamstring autografts performed between 2005 and 2012. Inclusion criteria were primary anterior cruciate ligament rupture, single-bundle 4-strand hamstring autograft, and a minimum 10-year follow-up. Cases of multiligament injury, allograft use, or revision surgery were excluded. At arthroscopy, knees were assigned to remnant-preserved ACLR (RP-ACLR) when a continuous stump thicker than 50% of the native bundle was retained; otherwise, they were assigned to non-remnant ACLR (NR-ACLR). The Tegner score, Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Lachman and pivot-shift tests, coronal alignment, and graft failures were evaluated. The minimal clinically important difference defined responder status. Kaplan-Meier and standard parametric or nonparametric tests were performed to compare groups, with P < .05 defined as statistically significant. This study enrolled 91 patients (51 RP-ACLR and 40 NR-ACLR) with a mean follow-up period of 164.1 ± 38.4 months (157.2 ± 30.4 months vs 172.9 ± 45.5 months, P = .126). Baseline age, sex, and body mass index were comparable. The 10-year survival rate was higher in the RP-ACLR group (92.5% vs 83.0%, P = .040). Failures occurred in 5 of 51 RP-ACLR patients (9.8%) and 11 of 40 NR-ACLR patients (27.5%, P = .050). Grade 3 pivot shift was observed in 3 RP-ACLR and 8 NR-ACLR patients (P = .009), and overall pivot shift grades favored RP-ACLR patients (P = .040). The Tegner score (P = .794), Lysholm score (P = .551), IKDC score (P = .136), Lachman test (P = .695), weight-bearing line ratio (P = .407), and mechanical axis (P = .202) showed no differences. The minimal clinically important difference responder rates were comparable for the IKDC score (100% in each group), Lysholm score (100% in each group), and Tegner score (7.8% in the RP-ACLR group vs 7.5% in the NR-ACLR group). Remnant preservation in isolated primary anatomic ACLR using hamstring autografts provides higher 10-year graft survival and superior rotational stability compared with non-remnant ACLR, with no significant differences in patient-reported outcomes, knee stability tests, coronal alignment, osteoarthritis progression, or the proportion of patients achieving clinically important improvement. Level III, retrospective comparative case series.