Evaluation of radiographic findings in painful hip arthroplasties.

A retrospective study of 50 surgically confirmed painful hip arthroplasties was performed to identify the roentgenographic findings that are most important in the detection of component loosening or infection. Plain film radiographs and subtraction arthrograms were reviewed in all cases, and specific features revealed by these two radiographic modalities indicative of component failure were identified. Seventeen patients had radioisotope bone scans and 13 of these had additional gallium scans. Plain film roentgenograms correctly identified loosening in 69% of acetabular and 84% of femoral components. Subtraction arthrography had an accuracy of 96% for both acetabular and femoral component loosening. Scintigraphic studies were correct in 77% of acetabular and 89% of femoral components; gallium scans identified 77% of infected hip prostheses.