Diagnostic value of bone scintigraphy for aseptic loosening after total knee arthroplasty

BACKGROUND: Despite technical improvements, aseptic loosening after total knee arthroplasty (TKA) remains a frequent complication. A one-stage revision arthroplasty is the most common therapeutic pathway. OBJECTIVE: The aim of this study was to evaluate the diagnostic value of bone scintigraphy in detecting aseptic loosening after TKA. METHODS: We retrospectively identified 46 cases of one-stage revision TKA performed between January 2011 and December 2012. In each case a bone scintigraphy was performed at least one year after the primary TKA and 3.2 +/- 2.2 month prior to revision arthroplasty. Additionally, we evaluated the rate of satisfaction and pain level 16.2 +/- 5.4 months after one-stage revision arthroplasty. RESULTS: Bone scintigraphy indicated aseptic loosening in 28 cases. Intraoperative aseptic loosening was verified in 34 cases. Bone scintigraphy had a sensitivity of 0.76 and a specificity of 0.83 in detecting aseptic loosening. The positive predictive value was 0.93, and the negative predictive value 0.56. At follow-up consultation, 35 patients were very satisfied or satisfied, and 31 patients had no pain or occasional pain. CONCLUSIONS: Bone scintigraphy is a helpful tool in detecting aseptic loosening after TKA. Nevertheless, the results from bone scintigraphy should be compared with clinical findings and patients' disorders.