[Procalcitonin as a sensitive index of chronic infection after artificial joint replacement:a retrospective analysis]

To study the predictive value of procalcitonin as a serum biomarker in diagnosis of late periprosthetic joint infection(PJI) for providing theoretical reference basis for diagnosis of PJI.

A total of 77 cases were retrospective included from January 2015 to December 2017 for revision of total hip arthroplasty and total knee arthroplasty, according to the diagnostic criteria of Musculoskeletal Infection Society(MISI). All cases were divided into infection group and non-infection group. Infection group included 21 cases, 7 cases for male and 14 cases for female, with an average age of (60.70±8.75) years old (ranged 43 to 75 years old). Non-infection group 56 included cases, 24 cases for male and 32 cases for female, with an average age (64.40±12.14) years old (ranged 43 to 85 years old). Concentration of preoperative serum procalcitonin was examined and the chi-square test was used to compare positive rate between the two groups.

Two cases in the infection group had positive serum procalcitonin, 0.06 ng/L and 0.10 ng/L respectively, with the positive rate of 9.52%; 4 cases in non-infected group had positive serum procalcitonin, 0.05 ng/L, 0.06 ng/L, 0.06 ng/L, 0.16 ng/L respectively, with the positive rate of 7.14%. No statistically significant difference was observed between the two groups (P=0.662).

Most of PJI were low toxicity infection with little systemic inflammatory response, so the concentration of serum procalcitonin was normal or slightly higher level, had little clinical significance for diagnosis of PJI. But the cases of this retrospective study are not enough, more cases are needed for further study.