No change detected by DEXA in bone mineral density after periacetabular osteotomy.

The purpose of this study was to assess acetabular bone mineral density after periacetabular osteotomy and to examine whether bone mineral density correlates with postoperative migration of the osteotomised acetabular fragment. Twenty-five female and three male patients scheduled for periacetabular osteotomy were consecutively included. The patients were scanned by dual energy X-ray absorptiometry (DEXA) at 1 week, 1 year, and 2 1/2 years after surgery. Radiostereometric analyses (RSA) were done at 1, 4, 8, and 24 weeks after surgery. Two and a half years after periacetabular osteotomy, no significant changes in bone mineral density or any biological effect on bone remodelling due a changed loading pattern in the acetabulum could be detected. There was no significant correlation between bone mineral density and migration of the acetabulum. Dual energy X-ray absorptiometry is not an appropriate method to demonstrate the changes in bone mineral density after periacetabular osteotomy or to predict postoperative acetabular migration.