Hybrid Therapy of Hip-Spica Cast Followed by Static Abduction Orthosis Provides a Similar Successful Outcome as Hip-Spica Cast Only in Infants with Late-Presenting Developmental Dysplasia of the Hip.

Objective: This study aims to investigate the therapeutic efficacy of hip-spica casting (HSC) and a hybrid treatment with a static abduction orthosis (SAO) following closed reduction of the hip for treating developmental dysplasia of the hip (DDH), in terms of the acetabular index (AI) and International Hip Dysplasia Institute (IHDI) grade. Materials and Methods: Patients diagnosed with DDH at a tertiary healthcare center between January 2017 and January 2020 were retrospectively evaluated using post-treatment X-rays. Diagnosis was confirmed through radiography. Twenty hips received HSC treatment for 12 weeks (Group HSC), and 18 hips underwent six weeks of HSC followed by six weeks of SAO treatment (Group SAO). After 12 weeks, AI angles and IHDI scores were collected. Successful treatment was defined as hip reduction achieved without surgical intervention. Results: The final AI angles for Group HSC and Group SAO were 25.1±3.3 (range: 20-31) and 24.2±2.6 (range: 20-30), respectively (p=0.389). AI improvement was 11.2±3.6 (range: 3-17) degrees for Group HSC and 10.4±3.7 (range: 4.8-17.2) degrees for Group SAO, with both treatment methods showing statistically significant improvements. Conclusion: Hybrid therapy with static abduction orthosis resulted in comparable improvements in AI angles and IHDI scores, as well as a similar success rate to HSC treatment alone. Replacing HSC treatment partially with SAO could offer advantages, including increased comfort and the elimination of anesthesia requirements.