Abstract
BACKGROUND: The persistently rising complication, pseudotumor, after hip arthroplasty required surgeons' vigilance. Although the remaining controversial relationship between metal ions and pseudotumor, metal ion detection had been widely employed in clinic. The aim of this study is to evaluate the correlation between metal ions and pseudotumor, as well as the effectiveness of metal ion analysis in the screening and diagnosis of pseudotumor through systematic review and meta-analysis. METHODS: The Medline and Embase databases were searched for studies evaluating metal ions and patients with pseudotumors after hip arthroplasty. A systematic review of risk ratio and diagnostic performance for metal ions was conducted. RESULTS: Seven studies were included in the systematic review. The mean Methodological Index for Non-Randomized Studies (MINORS) score of the included studies was 19 (range, 14 to 22). Pooled risk ratio (RR) value was 2.01(95% CI: 1.25-3.24; P = 0.004) for cobalt ions level and 1.44 (95% CI: 1.10-1.88; P = 0.008) for chromium ions level. The pooled sensitivity, specificity and the area under the curve (AUC) for cobalt and chromium ions were determined to be 0.59, 0.82, 0.73 and 0.34, 0.82, 0.56, respectively. CONCLUSIONS: The metal ions level has a low diagnostic value. It is of certain value for confirmation, but should not be used as a routine screening indicator. The diagnostic value of cobalt ions is higher than that of chromium. LEVEL OF EVIDENCE: Diagnostic Level IV.