To evaluate the short term results of a periacetabular rotational osteotomy in early and moderate osteoarthritis of hip dysplasia by comparing the clinical findings and radiological measurements.

Thirty-six cases (34 patients) who received periacetabular rotational osteotomy for hip dysplasia with pain and could be followed up for more than one year were reviewed. The clinical findings were evaluated by the range of motion and HHS. The radiological measurements were evaluated using the center edge angle (CE angle), Sharp angle, acetabular-head index (A-H index) and Tonnis grade.

The average Harris hip score improved from 79.4 points (60 to 89 points) to 95.1 points (82 to 100 points). The average range of motion did not change significantly. The mean CE angle increased from 7.1° (-7° to 19°) to 33.8° (27° to 44°), the mean sharp angle increased from 43.5° (26° to 53°) to 39.7° (30° to 49°), the mean A-H index increased from 56% (34% to 72%) to 90% (73% to 99%). The Tonnis grade had remained unchanged in 25 cases, improved in 9, and worsened in two. One case underwent total hip arthroplasty.

The periacetabular rotational osteotomy is the preferred method for treating hip dyaplasia and preventing secondary osteoarthritis. However, a skillful technique is mandatory.