Evaluation of the mid- to long-term outcomes of abduction orthosis treatment in patients diagnosed with developmental dysplasia of the hip

We aimed to evaluate the long-term durability of the abduction orthosis and treatment approach used in our clinic in patients with developmental hip dysplasia. June January 2010 – June 2021 In this study, which was evaluated retrospectively, medical records of all patients with developmental hip dysplasia who were treated with abduction orthosis method in Pamukkale University Faculty of Medicine Orthopedics and Traumatology Clinic were examined backwards. The data of 89 patients were obtained in the study. The data of 140 hips with patients with bilateral GCS were examined. Patients were called by phone and invited to the hospital for check-up and reassessment. Direct graphical records from the PACS system were examined and included in the study. The average patient reported using the device for 18.93 months out of an average of 87.38 months. 85.4% of the patients were female, with 13 hips on the right extremity, 25 hips on the left extremity, and 51 hips bilaterally. We observed that 50.7% of the patients with developmental dysplasia of the hip (DDH) were dysplastic, 41.4% were subluxed, and 5.7% had dislocation pathology. The majority of our patients, 61.4%, were in Tönnis Class 2. After treatment, all patients responded positively to the treatment with a Tönnis classification of Class 1. The pre-treatment acetabular angle was an average of 37.07, which decreased to 16.98 post-treatment. The center-edge angle was 26.32 and the femoral head coverage was 86.74%. There was a statistically significant correlation between the patients' pathologies and the acetabular angle and femoral head coverage (p<0.050). The change in angles with extremity direction was not statistically significant (p>0.050). Among the patients with dislocation pathology, 10 were Tönnis 3 and 1 was Tönnis 4, while patients with dysplasia reported better pathology with Tönnis Class 1 (50.7%) and Class 2 (49.3%). Four of our patients (2.9%) had residual acetabular dysplasia and no avascular necrosis occurred. As a result, Abduction orthosis can be applied safely and without complications in Tönnis Class 1, Class 2 and Class 3 patients. Considering the possibility of developing residual acetabular dysplasia in patients with Tönnis Clas 3 and Clas 4 dislocation pathology, we think that the clinical data of patients should be better evaluated and Abduction orthosis should be recommended.