Congenital patellar dislocation with genu valgum and Klinefelter syndrome: a case report.

Background: Congenital patellar dislocation (CPD) is a complex disease lacking consensus on the treatment. While genu valgum is a risk factor for patellar dislocation in general, it is less common in the congenital cases. In this report, a retrospective analysis of a child with bilateral CPD and genu valgum is presented, detailing the clinical characteristics, diagnostic approach, surgical intervention, and outcomes.

Case description: A 3-year-old boy presented with an abnormal gait and Klinefelter syndrome. Comprehensive preoperative imaging evaluations were made to assess osseous and soft tissue morphology, revealing bilateral CPD and genu valgum which localized to proximal tibia and knee joint. Surgical correction involved open reduction of both patellar dislocations with lateral retinacular release, medial retinacular reefing, temporary proximal tibial epiphysiodesis by eight-plate, and iliotibial band lengthening. Intraoperative patellar stability was satisfactory. At the 3-year follow-up, the patient showed normal patella tracking and favorable knee function.

Conclusions: CPD is a rare and complex pediatric disorder lacking a universally accepted treatment strategy. To date, there have been no reported cases of CPD presenting both genu valgum and Klinefelter syndrome. The immature skeletal system in children necessitates careful consideration of surgical techniques and early diagnosis to optimize growth, correct deformity, and ensure mobility. For the case, as the patellar dislocation and genu valgum can influence each other, a single-stage operation addressing both simultaneously was performed, resulting in a favorable outcome.