Abnormal patella height may be an independent risk factor in meniscal tears: a retrospective study in paediatric patients.

Purpose: The literature on factors predisposing to meniscal tears in the paediatric population focuses on concomitant injuries such as anterior cruciate ligament rupture (ACL) or abnormal meniscus morphology such as discoid menisci. Patella alta has been associated with ACL ruptures but its association with meniscal tears has not been described. The purpose of our study was to evaluate whether abnormal patella height is associated with isolated meniscus tears in skeletally immature patients METHODS: We retrospectively analysed all patients under 16 years of age who had an isolated meniscal tear diagnosis confirmed on arthroscopic surgery. We examined data on demographics, meniscal morphology and patella height using the Insall-Salvati and Caton-Dechamp ratios. We compared the incidence of meniscal tears to a literature derived sex and age matched asymptomatic control group with normal patella heights.

Results: A total of 39 patients with an isolated meniscal tear were identified (mean age 13.2years). Patella alta was present in 16 (41%). 21 had normal meniscus morphology, and 18 had a discoid meniscus. There was a significant association between patella alta and isolated meniscal tears compared to the control group (p = 0.001).

Conclusions: Our analysis is the first to demonstrate an association between abnormal patella height and the incidence of isolated meniscal tears in skeletally immature patients. Further research of knee biomechanics is required to elicit the mechanism and quantify the risk which may be used to guide prevention strategies and management of patients who wish to participate in high-risk sporting activities.