Medial Meniscal Ramp Lesion Repair Concomitant With Anterior Cruciate Ligament Reconstruction Did Not Contribute to Better Anterior Knee Stability and Structural Properties After Cyclic Loading: A Porcine Model

Abstract

Purpose: To investigate the biomechanical efficacy of medial meniscal ramp lesion (MMRL) repair in anterior cruciate ligament (ACL) reconstruction regarding the graft protection effect after cyclic loading. Methods: Specimens were randomized into 2 groups: (1) ACL reconstruction with unaddressed MMRL (Group U; n = 10), and (2) ACL reconstruction with repaired MMRL (Group R; n = 12). The specimens were tested cyclically (2,000 cycles, 0-40 N, 100 mm/min) in the direction of the native ACL and loaded to failure (100 mm/min) on a tensile tester. Statistically significant differences between the structural properties (length changes and anterior translations at the 100th, 500th, 1,000th, 1,500th, and 2,000th cycles, upper yield load, maximum load, linear stiffness, and elongation at failure) under cyclic loading and single-cycle loading were analyzed. Results: There were no significant differences in length changes and anterior translations at the 100th, 500th, 1,000th, 1,500th, and 2,000th cycles. There were no significant differences in upper yield load (82.4 ± 31.2 N in Group U, 90.0 ± 38.5 N in Group R, P = .62), maximum load (109.9 ± 28.6 N in Group U, 124.0 ± 56.4 N in Group R, P = .48), linear stiffness (12.1 ± 4.7N/mm in Group U, 12.5 ± 4.3 N/mm in Group R, P = .84), or elongation at failure (13.5 ± 7.3 mm in Group U, 16.6 ± 7.5 mm in Group R, P = .30). Conclusions: Simultaneous MMRL repair at the time of ACL reconstruction did not decrease length changes and anterior translations during cyclic loading. In addition, simultaneous MMRL repair at the time of ACL reconstruction did not contribute to better postoperative structural properties. Clinical Relevance: Simultaneous MMRL repair at the time of ACL reconstruction does not show a graft protective effect after cyclic loading. Graft elongation may occur during early rehabilitation.