Cementless total hip arthroplasty using the omnifit system: An 8.2 year follow-up study of 166 hips.

One hundred and sixty-six cementless primary total hip arthroplasties were performed in 133 patients with porous coated Omnifit prosthesis. The average age was 49.7 years. The mean follow-up period was 8.2 years with a minimum of 5 years. Good to excellent clinical results were achieved in 93% of patients. The overall revision rate was 5.4%. Radiographically, bone ingrowth occurred in all unrevised cups, and in 95% of unrevised stems. Osteolytic lesions appeared at an average of 3.8 years postoperatively. Femoral and pelvic osteolysis were seen in 21% and 4% of the surviving hips respectively. All femoral osteolytic lesions were found in the proximal Gruen zones 1 and 7. The mean annual polyethylene wear rate was 0.15 mm. Approximately one-third of the hips were observed to have excessive wear. Our experience with cementless Omnifit total hip prosthesis is encouraging. Of significant concern is the high incidence of excessive polyethylene wear and osteolysis.