NEW ORLEANS — Patients undergoing either total shoulder arthroplasty or rotator cuff repair for the first time had similar rates of developing positive cultures, of which Propionibacterium acnes were most of the cultures, according to results presented at the American Shoulder and Elbow Surgeons Annual Meeting.
Eric R. Ricchetti
Eric T. Ricchetti, MD, and colleagues obtained five intraoperative culture specimens, a synovial fluid sample and four tissue samples among 50 patients with glenohumeral osteoarthritis undergoing primary total shoulder arthroplasty and 50 patients without arthritis undergoing primary arthroscopic rotator cuff repair. Researchers sent all specimens for 14-day anaerobic culture hold for detection of P. acnes, and part of the synovial fluid sample was sent separately for measurement of 11 different cytokine levels. Researchers compared synovial cytokine levels between patients with and those without positive culture results, as well as across procedure type.
Ricchetti noted a 42% positive culture rate across cases with at least one positive culture, the majority of which were P. acnes.
“However, only 18% of these cases had growth of multiple cultures of the same organism,” Ricchetti said. “These were all P. acnes cases.”
Results showed no difference in the positive culture rate between procedures, and no association between a history of prior cortisone injection and higher positive culture rate. According to Ricchetti, none of the patients who had positive cultures had any clinical evidence of infection postoperatively.
“We did find that males showed a significantly higher positive culture rate than females for P. acnes and this went, again, across all cases for when you looked at these specific procedures,” he said.
Regardless of culture results, patients with arthritis had a significantly higher prevalence of multiple cytokines vs. patients without arthritis, Ricchetti noted.
“However, synovial cytokine levels were not significantly different when comparing cases with and without positive culture results, regardless of the procedure,” he said. – by Casey Tingle
Ricchetti ET, et al. Paper #19. Presented at: American Shoulder and Elbow Surgeons Annual Meeting; Oct. 12-14, 2017; New Orleans.
Disclosure: Ricchetti reports he is a board or committee member of the American Association of Orthopaedic Surgeons and of the American Shoulder and Elbow Surgeons; receives research support from DePuy; is a paid consultant for DJ Orthopaedics; and receives publishing royalties, financial or material support from the Journal of Bone and Joint Surgery – American.