Posterior root repair versus double-tunnel centralization in medial meniscus root tears: A propensity-matched analysis.

Abstract

PurposePosterior medial meniscus root tears often cause persistent extrusion and altered joint mechanics despite repair. This study compared standard transtibial pull-out repair with repair plus a second-tunnel centralization, hypothesizing better patient-reported outcomes without major MRI extrusion changes.MethodsThis retrospective two-center cohort (2019-2024) included adults with MRI-confirmed root tears treated with anatomic repair alone or with an additional centralization tunnel. Propensity matching yielded 96 patients (54 vs 42). The primary endpoint was 24-months change in IKDC score. Secondary outcomes included KOOS subscales, Lysholm, visual analogue scale pain, and Tegner activity. Structural outcomes-medial meniscus extrusion and Meniscal Extrusion Index-were assessed on coronal MRI at 12 ± 4 months. Analyses used ANCOVA adjusted for baseline values, supported by inverse-probability weighting and mixed-effects checks.ResultsBaseline characteristics were balanced. Extrusion changes were small and similar; residual pathologic extrusion rates were comparable (65% vs 62%). Centralization showed greater IKDC improvement (+5.7 points; <i>p</i> = 0.008) and higher KOOS-Quality of Life. Knees with ≥3 varus demonstrated additional benefit (interaction <i>p</i> = 0.048). Complications were infrequent.ConclusionsSecond-tunnel centralization significantly increased the probability of achieving <b>clinically meaningful functional improvement</b>, despite <b>unchanged static MRI extrusion</b>. This suggests dynamic load-sharing benefits not captured by static imaging. Therefore, centralization is recommended as a selective adjunct, particularly in <b>varus alignment</b>, rather than a routine necessity.