Significantly Higher Rate of Unexpected Positive Cultures in Revision Surgery Than in Primary Arthroscopic Shoulder Stabilization Surgery

PURPOSE: To evaluate the incidence of unexpected positive cultures (UPCs) in revision versus primary arthroscopic shoulder stabilization procedures. METHODS: Prospective comparative study of patients undergoing shoulder stabilization surgery. Thirty-four patients undergoing revision stabilization surgery and 34 undergoing a primary stabilization procedure were consecutively enrolled from August 2022 until December 2024. Inclusion criteria were patients undergoing primary or revision arthroscopic shoulder stabilization by the same surgeon. Patients with signs of infection or prior clinical infection, open surgery or recent antibiotic use were excluded. Intraoperative tissue samples were collected before prophylactic antibiotics and sent for microbiological analysis. Data on types of procedures, rate of positive cultures, isolated microorganisms, and demographic information (age, sex, body mass index, smoking, malnutrition, intravenous drug use, epilepsy, and immunosuppression) were recorded. RESULTS: The mean age of the cohort was 33.7 ± 10.2 years with 75% male and 25% female patients. There were no significant differences between groups regarding age, sex, smoking, and immunosuppressive state (P > .05). There were no significant differences in the type of procedure performed in primary surgery (soft tissue vs bone transfer) P > .05. The leading cause for revision was instability (91.2%) followed by stiffness (5.9%) and pain (2.9%). Revision surgeries had significantly higher rate of UPCs (P = .025) with 6 patients (17.6%) in the revision group and none in the primary group. Cutibacterium acnes was identified in 5 (83.3%) cases, while Staphylococcus aureus was identified in 1 (16.7%) case. CONCLUSIONS: The incidence of UPCs is significantly higher in revision arthroscopic shoulder stabilization procedures than in primary surgeries. LEVEL OF EVIDENCE: Level II, prospective comparative study.