Short- and MİD-TERM results of derotation, shortening and dega osteotomy in treatment of developmental hip dysplasia

Developmental Hip Dysplasia is a hip pathology in which high success rate can be achieved with early diagnosis and treatment. In cases with late diagnosis, femoral and acetabular side osteotomies may be required. In this study, it is aimed to evaluate the short- and mid-term clinical and radiological results of derotation, shortening and Dega osteotomy surgery performed in cases with late diagnosis. In our study, 22 patients (25 hips) were included who underwent derotation, shortening and Dega osteotomy due to Developmental Hip Dysplasia between 2019 - 2021 at Ankara City Hospital Orthopedics and Traumatology Clinic. Femoral anteversion angles of the patients, applied derotation and shortening amounts were determined. Patients were evaluated clinically and radiologically at the end of a mean follow-up period of 15±7.9 months (7 – 32 months). Preop acetabular index angles and Tönnis stages were compared with the values calculated in the early postop period and at the last control. Severin classification system was used for radiological evaluation, McKay classification system was used for clinical evaluation and Kalamchi-MacEwen for diagnosis of avascular necrosis at the final follow-up. The mean femoral anteversion angle was found to be 61° in patients. An average of 48° derotation and 1.5 cm femoral shortening were made. Femoral anteversion angle and the amount of derotation made due to this were found to be higher in patients with high preop Tönnis stage and younger age. In addition, more shortening were made in those with high preop Tönnis stage. An average improvement of 24° was obtained in the acetabular index angles of the patients at the last control compared to the preop period. Subluxation was detected in one patient during follow-up and the reason for this was evaluated as insufficient derotation. The rate of avascular necrosis is %28 in our study. Stable hip can be obtained with derotation, shortening and Dega osteotomy in cases of late diagnosed Developmental Hip Dysplasia and dysplasia is prevented by increasing acetabular coverage. Keywords: Dega osteotomy, derotasyon, developmental hip dysplasia, shortening,