Polygonal triple (Kotz) osteotomy in the treatment of acetabular dysplasia: 17 patients (19 hips) with 4-9 years of follow-up.

We reviewed 19 hips in 17 patients between 17 and 33 years of age, who underwent a Kotz polygonal triple osteotomy. Their average follow-up was 7 (4.5-9) years. Although 13 patients had less pain after surgery, 3 continued to limp. The average corrections were 36 degrees for the center-edge angle, 31 degrees for the vertical center-edge angle and 19 degrees for Sharp's angle. 3 patients developed transient palsy of the sciatic nerve, and 3 asymptomatic nonunion of the ischium or pubic bone. The degree of arthrosis decreased in 10 hips.