[Imaging evaluations of Salter innominate osteotomy for developmental dysplasia of the hip]

To evaluate the imaging efficacies after Salter innominate osteotomy for developmental dysplasia of the hip (DDH).

A total of 51 DDH patients with 70 hips were recruited between March 2011 to August 2012. All of them underwent Salter innominate osteotomy. Preoperative radiographs including acetabular index (AI), sharp angle (SA), obturator angle and obturator height were measured. And postoperative radiographs were taken at 2 days, 3 months, 6 months and 1 year to measure the parameters of AI, sharp acetabular angle, obturator angle, obturator height, shifting index and descending angle of distal iliac end. Paired t test was used for statistical analyses.

The average correction of AI was 35.5° ± 2.3° preoperatively versus 14.6° ± 1.6° postoperatively ( P = 0.000) . The average correction of Sharp angle was 50.6° ± 3.7° preoperatively versus 33.1° ± 3.2° postoperatively (P = 0.000) . The average correction of obturator angle was 58.3° ± 3.9° preoperatively versus 39.5° ± 2.8° postoperatively (P = 0.000) . The average correction of obturator height was (1.65 ± 0.26) cm preoperatively versus (1.10 ± 0.14) cm postoperatively (P = 0.000) . At 3 months, 6 months and 1 year post-operation, the average values of AI, SA, obturator angle and obturator height continued to fall. Both of them showed statistical improvement. Shifting index and descending angle of distal iliac end were 30.1% ± 3.6% and 31.3° ± 4.1° on average. Six (8.57%) Shenton lines were bad.

The imaging evaluations of acetabulum and pelvis show marked improvements until 1 year in DDH patients after Salter innominate osteotomy. It provides data reference for operative evaluations through measuring the imaging parameters of truncation bone.