High Prevalence of Hip Dysplasia in Patients with Scoliosis: A Retrospective Study

[Objectives] : There is a complex biomechanical relationship between the spine and hip joints, but the prevalence and clinical significance of developmental dysplasia of the hip (DDH) in patients with scoliosis have not been thoroughly investigated. This study aimed to assess the prevalence of DDH in patients with scoliosis and analyze their associations with different types of scoliosis. [ Methods] : A total of 331 patients with scoliosis (average age of 16.3 years; 73% female) were included in the study. Preoperative full-length spinal radiographs were used to measure the Cobb angle, lateral center-edge angle (LCEA) and Tönnis angle. Single-sample z tests were conducted to analyze the prevalence of DDH, and the results were compared with those of the general population. [ Results] : The overall prevalence of DDH was 27.5%, significantly higher than in the general population (1.52%). By subtype, the prevalence was 21% for idiopathic scoliosis, 39.6% for congenital scoliosis, 29.5% for neuromuscular scoliosis, and 30% for degenerative scoliosis. Among patients, 12.4% had bilateral dysplasia. [ Conclusions] : The prevalence of DDH is significantly greater in patients with scoliosis. This finding highlights the importance of systematically evaluating hip development in scoliosis patients to facilitate early intervention and improve outcomes.