Outcome measures of bipolar hip arthroplasty for atraumatic hip disorders - A preliminary report

Background: Bipolar hip arthroplasty was devised for fracture neck femur in elderly patients. Subsequently, indications have been expanded to include conditions affecting acetabulum like rheumatoid arthritis, osteoarthritis and avascular necrosis of femoral head. Materials and methods: We have studied the results of bipolar hip arthroplasty in 38 such patients, with severely involved acetabulum due to rheumatoid arthritis, avascular necrosis of femoral head and primary osteoarthritis. Acetabulum was reamed to get a tight ′equatorial′ or ′rim′ fit of the prosthesis. Prosthesis selected was 1 mm bigger than the maximum size of reamer used. Cement was used in femur whenever there was marked osteoporosis or wide medullary canal. Post operatively all patients were regularly screened for pain, range of movement, protrusio acetabuli, loosening / sinking of prosthesis and radiographic assessment of movement in the two bearings of prosthesis. Results: Overall results achieved were good to excellent in 80% of patients. Conclusions: The ultimate outcome is comparable to total hip arthroplasty. The added advantage is of low cost, simplicity of procedure and easy future revision.