Preoperative planning of severe recurrent patellar dislocation in children

Introduction The patellofemoral joint is a complex structure. Dysplasia of the trochlea and the adjacent portions of the lower limb has been shown to predispose pediatric patients to severe recurrent patellar dislocation. The comprehensive diagnostic workup has important implications for determining treatment of a complex multicomponent deformity of the patellofemoral joint in severe recurrent patellar dislocation. The objective of the study was to develop a preoperative diagnostic protocol for optimal surgical treatment of pediatric patients with severe recurrent patellar dislocation to enable complication rate reduction. Material and methods Between 2015 and 2017 54 patients diagnosed with patellar dislocation were treated at the Samara State Medical University hospital. Severe patellar dislocation according to the Volkov classification was identified in 37 patients. Patients were evaluated according to the algorithm described in the article and treated appropriately based on the findings. Results Multiplanar pathological changes were detected in the patellofemoral joint of all participants. The patients underwent supracondylar derotational varus osteotomy of the femur combined with a tibial tubercle medialization osteotomy to address multiplanar deformity. No complications were seen in 32 patients at a long term and re-dislocation occurred in one case. Four patients developed a contracture of the knee joint due to inadequate postoperative rehabilitation. Conclusion The thorough diagnostic workup is crucial for identifying treatment strategy of a recurrent patellar dislocation due to a complex structure of the patellofemoral joint and a multicomponent deformity at the anatomical site to avoid postoperative complications.