Abstract
Objective
To investigate the biomechanical basis and report preliminary clinical efficacy of eccentric rotational acetabular osteotomy (ERAO) when treating developmental dysplasia of the hip (DDH).
Methods
Biomechanical model of the hip joint was established on cadaveric hips. After performed ERAO on the biomechanical model, we explored the impact of this surgery on biomechanics of the hip joint. Meanwhile, we reported postoperative follow-up cases who underwent ERAO in our hospital between November 2007 to July 2012. A total of 14 patients (15 hips) were reported, including 4 males and 10 females, mean age was 30 years old. Harris hip score was defined as clinical evaluation standard and radiographic assessment was based on the measurement and further comparison of pre- and post-operative AHI (Acetabular-head index), CE angle (Center-edge angle) and Sharp angle.
Results
The established biomechanical model was accord with the physiological state of normal hip joint. Postoperative stress was not statistically significant compared with the preoperative stress. Meanwhile, by the end of follow-up, 13 patients (14 hips) were followed for an average time of 26 months, thus, the follow-up rate was 92.9%. Harris hip score improved from preoperative (67.1 ± 8.7) points to (88.1 ± 7.3) points; postoperative AHI increased an average of 39.6%, CE angle increased an average of 33.2 ° and sharp angle reduced an average of 9.6 °.
Conclusions
Both biomechanical study and preliminary clinical observation show that ERAO has the ability to correct the deformity of acetabulum. It enlarges the acetabular coverage of the femoral head and thus corrects the abnormal stress pattern. No bone graft is needed during the operation and postoperative rehabilitation is short, therefore, ERAO may have good curative effect when treating the DDH.
