80 adult patients with Crowe type I or type II developmental dysplasia of the hip (DDH) and secondary arthritis were randomized to receive either hip resurfacing arthroplasty (HRA) or total hip replacement (THR). The results indicate that those that received HRA had improved hip flexion compared to those that received THR. No difference in function was found between the groups. However, patients undergoing HRA had more bone loss from requiring a larger acetabular component. The effects of increased bone loss resulting from a large acetabular component diameter associated with the HRA procedure must be evaluated further to determine if any long term complications will arise.