Recent developments in diagnosis of periprosthetic joint infection

Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Currently, PJI is the main cause for knee revision and the third reason for hip revision. Accurate diagnosis is of quite importance for patients with potential in revision surgery. However, there is no test alone can achieve both perfect sensitivity and specificity in diagnosis of PJI. The following diagnostic methods still have irreplaceable role, including erythrocyte sedimentation rate (ESR), C reactive protein (CRP) test, synovial white blood cell count and polymorphonuclear percentage, bacteria culture and histology analysis. Some novel diagnostic techniques, such as leucocytes esterase strip test, show advantages in diagnosing as fast, convenient and cost-saving. Synovial biomarkers, such as α-defensin, have promising prospect with both high sensitivity and specificity. Among various diagnostic methods, bacteria culture and drug sensitivity test can guide the therapy of PJI. Thus, it is crucial to improve the positive rate of bacteria culture. With the development of technology, sonication and polymerase chain reaction (PCR) will be the future research highlights. Although the imaging technologies, such as labeled leukocyte imaging and 18F-fluorodeoxyglucose positron emission to-mography (18F-FDG PET), have been progressed in the past years, most of them are still in controversy. Further researches are still needed in the future.