Injury to the growth plate after Pemberton osteotomy.

The Pemberton osteotomy involves cutting directly into the iliopubic and ilioischial limbs of the triradiate cartilage of the acetabulum. Complete closure of the triradiate cartilage after this osteotomy has been described in case reports. The present experimental study was performed to determine whether physeal osseous bars formed after Pemberton osteotomy. Eight Pemberton osteotomies were performed in six piglets. The animals were killed, and the acetabula were studied with use of radiography, computed tomography, and histological analysis for evidence of physeal injury. Plain anteroposterior radiographs of the pelvis did not clearly demonstrate the formation of osseous bars. However, Bucholz radiographs, made with the acetabulum placed directly on the cassette, showed osseous bars in three of the four specimens that were studied in this manner. Histological sections of the eight specimens of triradiate cartilage demonstrated five osseous bars in the iliopubic limb and four in the ilioischial limb. In two specimens, there was disruption of the cartilage without osseous bridging. Only two of the eight specimens had normal histological findings in both the iliopubic and the ilioischial limb of the triradiate cartilage.