[Three-dimensional CT imaging in the treatment of children's developmental dislocation of hip].

Objective: To investigate the value of 3-dimensional CT in the treatment of developmental dislocation of hip (DDH).
Methods: From 2003.6 to 2007.6, the femoral neck anteversion (FNA) and morphology of acetebulum in 53 patients with DDH (61 hips) were studied by three-dimensional CT imaging. Among the patients, 12 patients were male and 41 patients were female, ranging in age from 3 to 16 years (mean 5.6 years). Thirty-four patients had dislocation in left hip joint, 11 patients had dislocation in right hip joints, and 8 patients had double dislocations. The patients were treated with Pemberton or Chiari acetabuloplasty and femoral osteotomy. After operation all the cases were obeserved by 3-dimensional CT again. The femoral neck anteversions were measured and the shapes of new acetabulum were observed.
Results: Among 61 hips of DDH, the maximum femoral neck anteversion was 90 degrees. The minimum was 35 degrees and the average was (45.6 +/- 11.4) degrees. Among 45 normal hips, the average femoral neck anteversion was (23.5 +/- 10. 2) degrees. The acetabulum were dysplastic according with what were found in the operation. After operation the femoral neck anteversions decreased and averaged (15.6 +/- 5.8) degrees. The femoral head containment improved.
Conclusion: The advantages of 3D CT scan includes manifestation of acetebular morphology, correct measurement of femoral neck anteversion and evaluation of operative procedure and efficacy. The 3-dimensional CT method is deserved to use widely in the treatment of developmental dislocation of hip in children.