Which Factors Increase the Risk of Re-Operation after Meniscus Surgery in the Skeletally Immature?

OBJECTIVES: The purpose of this study is to determine which factors heighten the risk for subsequent operations in skeletally immature patients undergoing meniscus surgery. METHODS: A retrospective institutional database of 1,063 meniscus surgeries performed between 2000 and 2015 was reviewed. All procedures were performed in skeletally immature patients. Demographic and intra-operative information was recorded, as were concurrent injuries or operations and subsequent surgeries. Univariate analysis consisted of chi-square and independent-samples t-tests. Multivariate logistic regression was then performed to control for confounding factors. RESULTS: The mean age at initial surgery was 13.4 years (standard deviation, SD, 2.2 years) and the average follow-up duration was 47 months (SD 54 months). Overall, 314 patients (29.5%) required repeat surgical intervention. 36% of all females required subsequent surgery compared to 26% of males (p<0.01). Discoid menisci underwent repeat operation more frequently than non-discoid menisci (35% vs. 27%, p=0.01). After accounting for confounders in a multivariate model, females had 2.2 times the odds of repeat surgery than males (95% CI 1.4-3.3, p<0.01) and each year of increasing age resulted in 1.3 times higher odds (95% CI 1.1 -1.4, p<0.01). The odds of subsequent surgeries were 4.2 times higher in those with flap tears (95% CI 1.8-9.7, p<0.01) and 2.9 times higher for discoid menisci (95% CI 1.4-6.0, p<0.01). Concomitant anterior cruciate ligament rupture or tibial spine fracture decreased the risk of needing additional surgeries in univariate analysis, but lost statistical significance in the multivariate model. CONCLUSION: Even when accounting for other factors in a multivariate model, female sex, increasing age, flap tears, and discoid meniscus were risk factors for subsequent procedures after meniscus surgery in skeletally immature patients. The re-operation rate in this population may be higher than previously reported. This study describes, for the first time, risk factors for repeat operations in skeletally immature patients undergoing meniscus surgery. These results can be used to counsel and monitor patients accordingly.