Use of computerised tomography in postoperative evaluation of congenital hip dislocation

ABSTRACT

This study included 22 patients, all of whom had the diagnosis of congenital hip dislocation. There was 18 girls and 4 boys with a total of 28 hips. Operative procedures included open reduction and capsulorrhaphy [27 hips], Salter osteotomy [12 hips] and femoral osteotomy [6 hips]. Operations were performed at the average age of 1.9 years. All scanning was done through the spica cast, no anaethesia or sedation was required. Infants were taken to the CT suite 24-48 hours after operation. All scans were performed by a schimadzu 3000 CT scanner with 5-mm slice depth, 4.5-sec. scan time and 1024 X 1024 matrix. Cuts were made through the superior acetabular margin the triradiate cartilage and the inferior portion of the acetabulum. A total of 35 scans were performed, Persistent posterior subluxation or dislocation of the femoral head was detected on the CT scan in 5 hips that necessitated repositioning within the cast [2 hips] and repeat open reduction [3 hips]. Plain radiographs failed to discover such malposition in the transvere plane. We concluded that postoperative evaluation of CDH should not depend only on plain X-rays, CT scanning should also be included