Radioisotopes in the investigation of complications after total hip and knee replacement
Biotenski, A.; Besser, M.; Israel, O.; Reis, D.
Harefuah 108(3): 131-134
1985
ISSN/ISBN: 0017-7768 PMID: 4007649 Document Number: 256772
A series of 40 patients who underwent total hip or knee joint replacement complained of pain in the region of the implant of from months to several years after the operation. During the diagnostic work-up to find the cause of the pain, each patient underwent a series of laboratory tests that included: plain radiographs of the painful joint, Tc-99m-methylene diphosphonate bone scanning, and when infection was supected, a gallium-67 scan. 26 had further surgery, and the diagnosis made during the second operation was retrospectively compared to the diagnosis made by each of the six pre-operative tests. Plain radiographs diagnosed loosening of the implant better than the bone scan (85.7% sensitivity and 100% specificity, versus 61.9% sensitivity and 84.6% specificity, respectively). Both tests diagnosed loosening of the femoral component better than that of the acetabular component in total hip arthroplasty. In the group suspected of infection around the implant, both plain radiographs and bone scans were of low efficiency (40% sensitivity and 100% specificity versus 33.3% sensitivity and 80% specificity, respectively). In contrast, gallium-67 scan was 80% sensitive and 100% specific in the diagnosis of infection around the implant.