Surgical Timing and Outcomes in Medial Meniscus Posterior Root Tear Repair: A Systematic Review

BACKGROUND: Medial meniscus posterior root tears (MMPRTs) compromise hoop stress transmission and tibiofemoral load distribution, accelerating degenerative changes comparable with total meniscectomy. While early repair has been recommended, many patients present late because of a delayed diagnosis or an insidious onset of symptoms. The effect of delayed surgical management on outcomes remains unclear. PURPOSE: To systematically review the literature comparing clinical outcomes, radiological progression, and complication rates of MMPRT repair performed at <3 months, 3 to 6 months, and >6 months after the injury. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic search of PubMed, Embase, and Scopus was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and registered with PROSPERO. A total of 11 studies (366 patients) reporting isolated transtibial pullout repair with a documented time from injury to surgery were included. Extracted data included patient-reported outcome scores (International Knee Documentation Committee [IKDC], Lysholm), osteoarthritis progression by the Kellgren-Lawrence grade, meniscal extrusion, healing status, and surgical failures or complications. RESULTS: Across all surgical timing groups, MMPRT repair resulted in significant functional improvements. Patients treated at <3 months demonstrated the greatest gains (IKDC: +39.0; Lysholm: +44), while those undergoing repair at 3 to 6 months also achieved clinically meaningful improvements (IKDC: +26.5 to +31.8; Lysholm: +25.0 to +40.4). Delayed repair >6 months remained beneficial, with increases of +22.9 in the IKDC score and +33.1 to +36.1 in the Lysholm score. Subgroup analyses confirmed statistically significant improvements in both the IKDC and Lysholm scores at all time points. Osteoarthritis progression by the Kellgren-Lawrence grade was reported in 24.2% of patients treated at <3 months, 30.2% to 52.2% at 3 to 6 months, and 4.8% to 10.0% at >6 months. Magnetic resonance imaging showed variable meniscal extrusion changes, with partial to complete healing observed in both the 3- to 6-month group and >6-month group. Failure rates ranged from 5.9% to 20.9% without a consistent association with surgical timing. CONCLUSION: Both early and delayed repair (<3 months and >6 months, respectively) yielded significant improvements in outcomes for patients with MMPRTs; however, the early repair group had clinically significant increases in patient-reported outcomes over the delayed repair group. Although data were limited by the number and quality of included studies, this finding suggests that while delayed repair of the meniscus root results in worthwhile improvements for properly selected patients and meets the minimal clinically important difference, early treatment of these tears should be pursued to limit the knee's exposure to altered biomechanics and to provide patients with the best chance at complete healing and lasting improvements. REGISTRATION: CRD420251145118 (PROSPERO).