LAHAINA, Hawaii — Although it can be difficult to diagnose periprosthetic joint infections, a speaker here said erythrocyte sedimentation rate and C-reactive protein aspirations that reveal an elevated cell count can help surgeons make this determination.
In his presentation, Wayne G. Paprosky, MD, FACS, noted that according to clinical practice guidelines, surgeons should risk-stratify patients as having either a higher or lower probability of periprosthetic joint infection (PJI).
Wayne G. Paprosky
“What are the examples of high probability prior to history of infection? [Some are] obesity, inflammatory arthritis, early implant loosening less than 5 years,” Paprosky said. “Probably anything loose less than 5 years that was done properly is probably infected until proven otherwise. Early osteolysis is another thing that you have to be suspicious.”
He said assessment using erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) is inexpensive, and patients with two negative results have a low risk of PJI. Paprosky added joint aspiration, which is also inexpensive, should be performed if ESR/CRP or suspicion of infection is high. However, use of CT is not conclusive and intraoperative gram stains have a low value, according to Paprosky.
“Intraoperative frozen sections, you need to talk to pathologists, are subjective [and] prone to sampling error,” he said, noting evidence for selective use of intraoperative frozen sections had “strong strength” in the guidelines.
He also noted surgeons should get multiple cultures if the patient presents with anything out of the ordinary and that tissue cultures are the best.
“With respect to antibiotics, do not give them,” Paprosky said. “[Do] not give antibiotics until you have a diagnosis.”
Paprosky added that alpha-defensin testing has a high sensitivity and specificity for PJI.
“Certainly, I think when we look at this, [alpha-defensin testing] outperformed the leukocyte esterase test,” he said. “I think synovial fluid alpha defensin plus an elevated CRP certainly has shown, at least in this study, to have a high positive value analysis.” – by Casey Tingle
Paprosky WG. Diagnosis of periprosthetic joint infections. Presented at: Orthopedics Today Hawaii 2017; Jan. 8-12, 2017; Lahaina, Hawaii.
Disclosure: Paprosky reports that he receives royalties from Zimmer and Stryker; and is a consultant for Zimmer, Medtronic-Salient, Stryker, DePuy and Intellijoint.