With the growing number of patients that are being treated with hip arthroplasty, the number of patients that require revision surgery is increasing as well. In clinical practice, the diagnosis of a loose hip prosthesis is, in addition of clinical evaluation and radiographic techniques, often made using scintigraphic techniques. However, with regard to the performance of these techniques, reported results have shown to be inconsistent or sometimes even contradict when assessing the acetabular component. Therefore, in order to evaluate the test performance and efficacy of radiographic and scintigraphic techniques in the evaluation of patients suspected of aseptic loosening of acetabular components, we conducted a systematic review and meta-analysis of clinical studies. In order to identify all studies that examined the use of radiographic or scintigraphic techniques in the evaluation of aseptic loosening of the acetabular component, we used systematic methods to identify English-language published papers and human-adult studies published between January 1975 and December 2001. Using a modified checklist, designed by the Cochrane Methods Group on Systematic Review of Screening and Diagnostic Tests, a quality analysis was performed by two independent reviewers. There were 18 studies (n=1026) analysing the performance of plain radiography, 24 studies (n=825) regarding contrast arthrography, five studies (n=203) describing the performance of nuclear arthrography and 15 studies (n=549) regarding bone scintigraphy. Pooled sensitivity for plain radiography was 77% (spec. 82%), contrast arthrography revealed a sensitivity of 82% ( spec. 73%), nuclear arthrography 82% (spec.58%) and bone scintig-raphy 70% (spec.73%). Pooled sensitivity and specificity showed that plain radiography, due to the high specificity, appears to be the technique of first choice in the assessment of patients suspected of aseptic loosening of a acetabular component, followed by contrast arthrography, due its higher specificity compared with nuclear arthrography. However, the methodological quality of the majority available studies was limited.
