Clinical and MRI features of patellar instability in children

BACKGROUND: Patellar instability refers to recurrent dislocations and subluxations of the patella relative to the femoral trochlear groove. This condition is one of the most common disorders of the knee joint in pediatric patients. Both bone and soft tissue structures act as stabilizers of the patella, and alterations in any of these components may contribute to patella instability. Magnetic resonance imaging (MRI) findings related to the osteochondral and soft tissue structures of the patellofemoral joint in children with patellar instability, as well as their correlation with clinical presentation, are of practical interest. AIM: This study aimed to assess the key MRI features of the patellofemoral joint zone in pediatric patients with patellar instability and evaluate their clinical manifestations. METHODS: Epidemiological, clinical, and MRI data were analyzed for patients with patellar instability and anterior cruciate ligament injury. The study included 52 patients in the main group and 44 patients in the comparison group with anterior cruciate ligament injury. No statistically significant differences in age distribution were observed. RESULTS: Significant differences were identified between the groups in terms of Wiberg patellar type, presence of a patellar apprehension sign, and patellar hypermobility. Differences were also noted in the lateral inclination and depth of the trochlear groove, as well as in the frequency of clinical signs such as patellar apprehension and patellar hypermobility (p 0.001). CONCLUSION: Trochlear dysplasia is a key predisposing factor for the development of patellar instability in pediatric patients. This study confirmed statistically significant differences in the parameters characterizing trochlear dysplasia, as well as the influence of this factor on patellar instability in children, including its correlation with clinical manifestations.