Effect of intra-articular tibial tunnel aperture positioning on the clinical outcomes after repair of medial meniscus posterior root tear with pull-out repair technique.

Abstract

The impact of tibial tunnel aperture position on outcomes after medial meniscus posterior root (MMPR) repair with a transtibial pull-out technique remains unclear. This study evaluated the association between intra-articular tibial tunnel aperture position and postoperative outcomes after transtibial pull-out MMPR repair using intra-articular assessment. Patients who underwent arthroscopic MMPR repair between March 2010 and February 2022 were retrospectively reviewed. The tibial tunnel aperture was classified relative to the MMPR footprint midpoint as anterior (Group A; 28 patients) or posterior (Group P; 30 patients). PROMs (VAS, Lysholm score, International Knee Documentation Committee subjective score, and KOOS) and radiologic outcomes (changes in joint space width and Kellgren-Lawrence (K-L) grade progression) were evaluated at ≥ 2-year follow up. Postoperative outcomes did not differ significantly between groups. However, Group A showed higher rates of K-L grade progression (67.8% vs. 36.7%; P = 0.031) and greater medial joint space narrowing (0.9 mm (interquartile range 0.4-1.4) vs. 0.3 mm (interquartile range 0.0-0.6), P = 0.001) than Group P. Joint space narrowing demonstrated a significant positive correlation with the normalized anteroposterior distance of the tibial tunnel aperture (r = 0.459; P < 0.001),indicating that more anterior tunnels were associated with greater joint space loss. Anterior placement of the intra-articular tibial tunnel aperture was associated with unfavorable radiologic outcomes, including joint space narrowing and progression of the K-L grade. Notably, the normalized anteroposterior distance of the MMPR footprint to the center of the tibial tunnel aperture showed a significant correlation with joint space narrowing.