Abstract
One hundred fifty one total hip arthroplasty (THA) with metal on metal hip system of without cement were followed at a mean of 5. 5 years (range 2. 6 years to 7 years). Original diseases were 134 hip in 123 cases with osteoarthritis and 17 hips in 13 with rheumatoid arthritis. The average Harris hip score of before the operation was 45. 3 points and at the follow-up time the average score was 88. 5 points.
Radiographic findings in the incidence of partial radiolucent line around the component: in the acetabular component, no radiolucent line was observed, in the femoral component, marginal lucent lines were 8. 6% (13 hips). Cortical hypertrophy was observed in high ratio of 27. 2%(41 hips). There was no loosening and tilt of component over 5 degrees observed in any patient. Postoperative dislocation of the hip was observed 9 hips (6. 0%).
Cobalt concentrations and chromium concentration in the serum were measured in cases in metal on metal total hip, metal on poly arthroplasty and in controls without implants. Serum was assayed using graphite furnaces atomic absorption spectrophotometer. No patients were seen of elevation in serum cobalt and chromium concentrations.
The authors conclude that THA with metal on metal system has presented excellent results for mid term follow-up in our hospital.
