Seven to 10 years followup of an anatomic hip prosthesis: an international study

Hypothetically, hydroxyapatite-coated anatomic-shaped femoral stems and hemispheric acetabular cups should improve biologic fixation of the implant and strength transmission to the bone, improving unsatisfactory results of the first cementless hip prosthesis focused on the stress-shielding phenomenon at the femur and failure of the threaded acetabular cups. A consecutive series of 312 patients who had primary Anatomique Benoist Giraud hip prostheses unilaterally implanted were followed up. We analyzed the clinical and radiographic results and report the outcomes 7-10 years after implantation. Two hundred thirty-two patients were assessed at 7-10 years. The survival rate for the implant was 96.8%; 77.2% of patients had no pain, 72.4% maintained total mobility, and 62.9% were able to walk without restrictions. However, radiologic assessment shows that problems improved but did not disappear. More than 55% of femurs had signs of proximal stress-shielding develop. More important, substantial polyethylene wear was observed in at least 62% of the acetabular inserts at 7-10 years followup.