Serum Procalcitonin as an adjunct in diagnosing prosthetic joint infection in total knee replacement and total hip replacement.

There are still many unknowns regarding the potential application of Procalcitonin (PCT) as an adjunct to aid the diagnosis of Prosthetic Joint Infection. A systematic review searching scientific articles was performed with keywords "Procalcitonin", "Total Hip Replacement", and "Total Knee Replacement" (n=123). After review of the abstract and full text for relevance, ten articles were included (n=10). Serum PCT levels for chronic Total Hip Replacement (THR) and Total Knee Replacement (TKR) have a range of mean values from 1.5 ng/ml to 14.2 ng/ml. Specificity ranges from 0.27 to 0.98, while sensitivity is from 0.33 to 0.9. On primary THR/TKR with confirmation of non-infected status, serum PCT peaks between 1-3 days post-operatively, with peak levels varying from 0.12 - 0.79 ng/ml. Based on this review, serum PCT is not a good adjunct in diagnosing Prosthetic Joint Infection (PJI). Synovial fluid PCT fluid may add better clinical support but requires further studies. There were several limitations with this review: the studies are small and heterogeneous, there was a variable definition of PJI, and there was a wide range of mean values, sensitivity and specificity.