ANTIBIOTIC PROPHYLAXIS IN SHOULDER ARTHROPLASTY – increased number of early infection revisions in patients treated with clindamycin compared to cefuroxime

Background Periprosthetic joint infection (PJI) is a serious complication following shoulder arthroplasty (SA). The purpose of this study was to compare the risk of early infection revision in patients given either clindamycin or cefuroxime antibiotic prophylaxis at time of surgery. Methods We analyzed electronically recorded data from the Finnish Shoulder Arthroplasty Registry from 2016 to 2021. The primary endpoint was revision due to infection within one year after surgery. Hazard ratios (HR) with 95% confidence intervals were calculated using Cox proportional hazards regression to compare clindamycin and cefuroxime prophylaxis. Age and sex were included as covariates in the model. Because revision indications were frequently missing, sensitivity analyses were conducted using predefined time-based scenarios. Results There were 3595 registered primary shoulder arthroplasties during the study period. Of these, 1382 (38%) received clindamycin, and 1050 (29%) cefuroxime prophylaxis; prophylaxis information was missing for 969 (27%) arthroplasties. There were 87 (2.4%) revisions within one year (among these 12 (14%) were recorded as infection-related, and in 63 cases (76%) the reason for revision was missing). Six infection revisions occurred in the clindamycin group, and one in the cefuroxime group. In the analysis including only confirmed infections the adjusted HR for infection revision with clindamycin compared with cefuroxime was 4.51 (CI 0.54-37.56; p=0.16). In the sensitivity analyses accounting for missing revision indications HR estimates ranged from 1.78 to 3.19, respectively. The absolute difference in one-year infection-free survival between groups ranged from 0.3 to 0.9 percentage points, favoring cefuroxime. Conclusions Clindamycin antibiotic prophylaxis may result in more early infection revisions in shoulder arthroplasty when compared to cefuroxime prophylaxis. This finding suggests that cefuroxime may be preferred over clindamycin for routine prophylaxis, although missing data warrant cautious interpretation. Level of evidence Level III, Retrospective Cohort Comparison using Large Database, Treatment Study