Integral porous femoral stem: 5- to 8-year follow-up study

The outcome of total hip arthroplasty without cement was prospectively followed in patients who received a titanium taper wedge femoral component with a circumferential titanium plasma spray coating on the proximal surface (Integral femoral stem, Biomet, Warsaw, IN). One hundred ninety femoral components were implanted in 179 patients. Nine patients (9 hips) died prior to their 5-year examination, leaving 170 patients available for follow-up evaluation. Thirty-one of the 170 patients (33 hips) were lost at an intermediate follow-up period of 5 years (mean, 5.8 years, range; 5–8 years), giving a follow-up rate of 82% for patients and hips. The preoperative diagnoses included osteoarthritis (91 hips), avascular necrosis (38), post-traumatic arthritis (10), rheumatoid arthritis (4), congenital dislocation of the hip (3), and fractures (2). The 78 men and 61 women had a mean age of 55 years (range, 18–81 years) and a mean weight of 81 kg (range, 50–136 kg). Preoperative Harris pain and function scores for the hip were 19.9 (range, 0–40) and 55.6 (range, 12–84), respectively. At the most recent follow-up visit, the mean pain score increased to 41.2 (range, 10–44) and the mean function score increased to 93.5 (range, 6–100). Thigh pain was present in 4% of the hips at the most recent follow-up visit. Radiographically, 99% of the femoral components demonstrated spot welds in the porous-coated zone. Two hips had demarcation of the femoral component in the porous-coated zone consistent with fibrous fixation. None of the femoral stems had been revised and there were no signs of aseptic loosening. Additionally, there were no cases of pain that could be directly attributed to the stem and there was no evidence of distal femoral osteolysis. It is concluded that the Integral femoral stem provides excellent clinical and radiographic results at intermediate follow-up periods.