Larger preoperative medial meniscus extrusion is associated with insufficient pain relief following pullout repair for medial meniscus posterior root tears.

Purpose: We aimed to evaluate preoperative factors associated with postoperative pain after transtibial pullout repair for medial meniscus posterior root tears (MMPRT), focusing on patient characteristics and imaging findings, including bone morphology and preoperative medial meniscus extrusion (MME). Methods: Patients who underwent isolated transtibial pullout repair for MMPRT at our institution were included in this retrospective study. Preoperative knee joint radiographs were evaluated for the Kellgren-Lawrence grade and bone morphology. Additionally, MME was measured using preoperative and 1-year postoperative magnetic resonance imaging. The Knee Injury and Osteoarthritis Outcome Scores (KOOS)-Pain subscale was evaluated preoperatively and at final follow-up. Univariate and multivariate linear regression analyses were conducted to evaluate the association between postoperative KOOS-Pain and preoperative factors. Additionally, surgical revision rates for around-knee osteotomy and arthroplasty were evaluated. Results: Statistical analyses were conducted for 508 knees, of which 406 (79.9%) were female. The mean age was 65.3 ± 9.1 years (range, 24-86), and mean body mass index was 25.7 ± 4.2 kg/m Conclusions: In a large cohort of 508 knees, preoperative MME was independently associated with postoperative KOOS-Pain after transtibial pullout repair for MMPRT with early-stage knee osteoarthritis (Kellgren-Lawrence grade ≤ 2). The degree of preoperative MME does not predict failure of pullout repair for MMPRT; however, it is important to understand its association with postoperative pain and consider the indications for surgical intervention. Level of Evidence: Level IV.