BACKGROUND:Developmental dysplasia of hip refers to the deformity of acetabulum and proximal femur,which can lead to hip instability and hip osteoarthritis. Periacetabular osteotomy is the main treatment for non-terminal developmental dysplasia of hip in adolescents and adults. Pelvic inclination plays an important role in biomechanics of hip joint,which determines the stress direction of hip joint. In hip joint diseases,pelvic compensatory tilt can occur to minimize the abnormal stress of hip joint.OBJECTIVE:To observe whether periacetabular osteotomy changes pelvic sagittal tilt in patients with developmental dysplasia of hip,and to investigate the effect of acetabular covering on pelvic sagittal tilt.METHODS:A retrospective analysis was performed on 29 patients who underwent periacetabular osteotomy due to developmental dysplasia of hip in West China Hospital of Sichuan University from August 2019 to June 2022. Anteroposterior X-rays of the standing pelvis were collected before and 6 months after surgery. The pelvic tilt parameters,including the lateral center-edge angle,pubic symphysis to sacroiliac joint distance,pubic symphysis to sacroiliac joint midline distance,sacrofemoral-pubic angle,and pelvic tilt,were measured. Hip functions of all patients were assessed by hip disability and osteoarthritis score and Harris score before and 6 months after surgery.RESULTS AND CONCLUSION:(1) The lateral center-edge angle,pubic symphysis to sacroiliac joint midline distance,and sacrofemoral-pubic angle were significantly increased 6 months postoperatively compared to preoperative values (P<0.05). Tonnis angle and pelvic tilt were significantly decreased (P<0.05). There was no significant difference in pubic symphysis to sacroiliac joint distance between preoperative and postoperative measurements (P>0.05). (2) The hip disability and osteoarthritis scores and Harris scores were significantly increased 6 months after operation (P<0.01). (3) It is indicated that periacetabular osteotomy surgery can significantly improve acetabular coverage and the pelvis showed significant anteversion changes in patients with developmental dysplasia of hip.

BACKGROUND:Developmental dysplasia of hip refers to the deformity of acetabulum and proximal femur,which can lead to hip instability and hip osteoarthritis. Periacetabular osteotomy is the main treatment for non-terminal developmental dysplasia of hip in adolescents and adults. Pelvic inclination plays an important role in biomechanics of hip joint,which determines the stress direction of hip joint. In hip joint diseases,pelvic compensatory tilt can occur to minimize the abnormal stress of hip joint.OBJECTIVE:To observe whether periacetabular osteotomy changes pelvic sagittal tilt in patients with developmental dysplasia of hip,and to investigate the effect of acetabular covering on pelvic sagittal tilt.METHODS:A retrospective analysis was performed on 29 patients who underwent periacetabular osteotomy due to developmental dysplasia of hip in West China Hospital of Sichuan University from August 2019 to June 2022. Anteroposterior X-rays of the standing pelvis were collected before and 6 months after surgery. The pelvic tilt parameters,including the lateral center-edge angle,pubic symphysis to sacroiliac joint distance,pubic symphysis to sacroiliac joint midline distance,sacrofemoral-pubic angle,and pelvic tilt,were measured. Hip functions of all patients were assessed by hip disability and osteoarthritis score and Harris score before and 6 months after surgery.RESULTS AND CONCLUSION:(1) The lateral center-edge angle,pubic symphysis to sacroiliac joint midline distance,and sacrofemoral-pubic angle were significantly increased 6 months postoperatively compared to preoperative values (P<0.05). Tonnis angle and pelvic tilt were significantly decreased (P<0.05). There was no significant difference in pubic symphysis to sacroiliac joint distance between preoperative and postoperative measurements (P>0.05). (2) The hip disability and osteoarthritis scores and Harris scores were significantly increased 6 months after operation (P<0.01). (3) It is indicated that periacetabular osteotomy surgery can significantly improve acetabular coverage and the pelvis showed significant anteversion changes in patients with developmental dysplasia of hip.