title: A comparison of biomechanical changes on femoral head following rotational acetabular osteotomy and eccentric rotational acetabular osteotomy in normal cadaveric hip.
abstract: OBJECTIVE
  Both rotational acetabular osteotomy (RAO) and eccentric rotational acetabular osteotomy (ERAO) are effective procedures for young patients with developmental dysplasia of the hip. However, no comparative study of biomechanical changes has been reported following these two procedures. We therefore explored the stress changes on femoral head after RAO and ERAO under different load conditions.
  
  
  METHODS
  Twelve female cadaveric hips without deformity were divided into RAO group and ERAO group. Stress value on femoral head was measured preoperatively and postoperatively after the vertical force was loaded on the cadaveric spine from 0 to 500 N. Stress change value was then calculated base on the measurements.
  
  
  RESULTS
  In the RAO group, preoperative stress increased when loading on spine became larger, but postoperative stress changed its increasing trend into decreasing when the load was greater than 200 N (turning point). Same phenomenon was found in the ERAO group (turning point was 300 N). However, the difference between preoperative and postoperative stress was not statistically significant in both RAO and ERAO groups. Stress change value from each procedure showed similar trends. With the load growth, stress change increased firstly and then decreased, but the difference between RAO and ERAO was not statistically significant.
  
  
  CONCLUSIONS
  Both RAO and ERAO could correct the abnormal biomechanical effect of dysplastic hip; moreover, they may have similar biomechanical effects on femoral head, obtaining the same clinical outcomes. Non-biomechanical factors (surgical trauma, technical complexity, etc.) also play important roles in procedure selection.
authors: Department of Joint Surgery, Huangpu Joint Centre, Institute of Orthopedics, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, Guangdong, China.
authors: Ziqing
authors: Z
authors: Li
authors: Shiming
authors: S
authors: Yu
authors: Changhe
authors: C
authors: Hou
authors: Yi
authors: Y
authors: Chen
authors: Yangchun
authors: Y
authors: Zhang
authors: Qiyi
authors: Q
authors: Zhai
authors: Bo
authors: B
authors: Bai
authors: Puyi
authors: P
authors: Sheng
mesh_terms: D000077:Acetabulum / Q000502:physiology* / Q000601:surgery; D000328:Adult; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D005270:Femur Head / Q000502:physiology* / Q000601:surgery; D006621:Hip Joint / Q000502:physiology* / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods; D013314:Stress, Mechanical; D016896:Treatment Outcome