Transtibial Centralization Using Peripheral Stabilization Suture Reduces Medial Meniscus Extrusion and Varus Progression 1 Year After Medial Meniscus Posterior Root Tear Repair

PURPOSE: To evaluate the clinical and structural effects of adding peripheral stabilization suture (PSS), an additional transtibial pullout centralization technique, to conventional transtibial pullout repair for medial meniscus posterior root tears (MMPRTs). METHODS: A retrospective review was conducted of patients who underwent MMPRT repair between April 2019 and March 2024 with at least 1 year follow-up. Patients were divided into conventional pullout repair and pullout repair combined with PSS. Medial meniscus extrusion (MME) was evaluated by magnetic resonance imaging (MRI) preoperatively and at 1 year postoperatively. Radiographic parameters including hip-knee-ankle angle (HKA), mechanical axis (%MA), and Kellgren-Lawrence (KL) grade were assessed. Patient-reported outcome measures (PROMs) were also collected. Minimal clinically important difference (MCID) for MME was calculated, and the proportion of patients exceeding this threshold was compared between groups. RESULTS: Thirty-five patients were included. At 1 year postoperatively, the PSS group showed significantly less MME (5.3 mm vs. 3.2 mm; P < .001), fewer cases of varus alignment progression (12 vs. 5; P = .018), and less radiographic KL classification progression (11 vs. 5; P = .044) compared to the conventional group. The %MA remained unchanged in the PSS group but significantly shifted medially in the conventional group. PROMs improved significantly in both groups, with no significant differences between them. MCID analysis showed that the rate of clinically meaningful worsening of MME was significantly higher in the conventional group than in the PSS group (15/17 [88.2%] vs 4/18 [22.2%], P < .001). CONCLUSIONS: The addition of PSS to conventional pullout repair for MMPRT effectively reduced postoperative MME and suppressed the progression of varus alignment and osteoarthritic changes at 1 year postoperatively, while both groups showed significant but comparable improvements in PROMs. LEVEL OF EVIDENCE: Level III, retrospective comparative study.