"Tension Suspension" Remnant-Preserving ACL Reconstruction Promotes the Early Maturity of the Graft Ligament.

Abstract

Purpose: The clinical application of anterior cruciate ligament (ACL) remnant preservation remains controversial, and conventional remnant-preserving techniques cannot fully maximize the biological potential of ACL remnants. To compare graft ligamentization, femoral tunnel enlargement, and clinical functional scores between "tension suspension" remnant-preserving anterior cruciate ligament reconstruction (ACLR) and single-bundle anatomical ACLR.

Methods: Forty-eight patients enrolled from December 2021 to June 2023 were divided into non-preserving remnant (NPR, n = 18) and preserving remnant (PR, n = 30) groups. At 3 and 6 months postoperatively, magnetic resonance imaging (MRI) of the knee was performed to measure graft signal noise quotient (SNQ) of the region of interest (ROI) and femoral tunnel diameter changes. Lysholm, IKDC, and Tegner scores were assessed at 6 months. Demographic and preoperative data were analyzed; intergroup comparisons of graft SNQ, femoral tunnel diameter changes, and clinical scores were conducted. Spearman correlation analysis evaluated the relationship between graft SNQ and knee function scores.

Results: No intergroup differences were noted in age, sex, BMI, or graft diameter. At 3 months, significant differences were observed in graft SNQ (most prominent at the distal end) and femoral tunnel diameter changes (p < 0.05). At 6 months, no significant differences were found in SNQ (except near-significant proximal SNQ, p = 0.058) or femoral tunnel diameter changes; clinical scores showed no intergroup differences. Tegner scores were moderately to significantly positively correlated with 6-month SNQ (< 0.05).

Conclusion: "Tension suspension" remnant-preserving ACLR has significant advantages in early graft ligamentization and inhibiting femoral tunnel enlargement. Subjective knee function may be related to graft signal intensity.