This study compares the posterior approach to the anterolateral approach using the ReCap® Total Hip Resurfacing System.

Theoretical considerations of RECAP procedures through anterolateral trochanteric osteotomy:

• Less bone resection, less complicated revision surgery.
• Reduced stress shielding of the femur.
• Lower incidence of hip dislocations.
• Walking function improved by change in mobilisation regime and operative technique.
• Risk of femoral neck fracture is reduced by preoperative measurement of bone density.
• Risk of avascular necrosis of the femoral head is reduced with the anterolateral approach preserving femoral head blood supply and preventing later failure of the implant.

Inclusion Criteria:

• Primary hip OA
• Secondary hip OA due to mild and moderate acetabular dysplasia
• Sufficient bone quality for cementless acetabular component
• Suited for resurfacing of the femoral head (pre- and intraoperatively assessed)
• >29 years
• <61 years

Exclusion Criteria:

• Neuromuscular or vascular diseases in affected leg
• Patients found intra-operatively to be unsuited for a cementless acetabular component or cementing of the femoral component
• Need of NSAID post-operatively
• Fracture sequelae
• Females at risk of pregnancy (no safe contraceptives)
• Severe hip dysplasia
• Sequelae from hip disease in childhood
• Medicine with large effect on bone density (K-vitamin antagonists, loop-diuretic)
• Alcoholism (females > 14 units per week, males > 21 units per week) AVN
• Osteoporosis