Predictors of Medial Meniscus Posterior Root Tear Repair Failure: Impact of Sex, BMI, Chondral Damage, and Rehabilitation
C.P. Helito, A.G.M. Da Silva, T.M. Guimaraes, M.F. Sobrado, R.G. GobbiObjectives:
To evaluate risk factors for failure of medial meniscus posterior root repairs, focusing on preoperative patient factors, surgical variables, and rehabilitation compliance, excluding known causes like uncorrected varus axis deviation and advanced medial compartment degeneration.
Methods:
Patients undergoing transtibial repair for medial meniscus posterior root tears with ≥24 months follow-up were included. Variables analyzed comprised demographics, time from injury to surgery, Kellgren-Lawrence and Outerbridge grades, surgical details, concomitant procedures, rehabilitation compliance, clinical outcome scores (IKDC, Lysholm, FJS, GPE), and repair failure assessed clinically and radiologically. Multivariable logistic regression with stepwise backward elimination identified factors associated with failure.
Results:
Among 154 patients (mean follow-up 48.8±18 months), 35 (22.7%) experienced failure. Significant predictors included female sex (p=0.001), higher BMI (p=0.001), advanced femoral (p<0.001) and tibial (p=0.018) chondral injury, single tibial tunnel use (p=0.043), and rehabilitation non-compliance (p<0.001). Lower clinical scores (IKDC, Lysholm, FJS, GPE) were also associated with failure (all p<0.001). Multivariable logistic regression identified female sex (adjusted OR=3.97, 95% CI=1.50–10.52,p=0.006), higher BMI (adjusted OR=1.17 per unit increase, 95% CI=1.04–1.32,p=0.011), femoral chondral lesions of Outerbridge grade 1 (adjusted OR=5.03, 95% CI=1.12–22.56,p=0.035) and grade 2 (adjusted OR=13.05, 95% CI=3.01–56.66,p=0.001), and non-compliance with rehabilitation (adjusted OR=3.40, 95% CI=1.17–9.93,p=0.025) as independent failure predictors. Only 8.5% of failed repairs exceeded the PASS IKDC threshold compared to 63.0% without failure.
Conclusion:
Transtibial medial meniscus posterior root repair showed a 22.7% failure rate at ≥2 years of follow-up. Female sex, elevated BMI, higher femoral chondral injury grades, and poor rehabilitation compliance independently predicted failure.