Complications of antibiotic cement spacers used for shoulder infections

Background: Our aim was to evaluate complications related to commercially available antibiotic cement spacers used in the treatment of shoulder infections. Methods: We performed a retrospective review of commercially available antibiotic spacers implanted in 53 patients (60 spacers) between April 2009 and October 2017 as part of a 2-stage treatment plan for infection at the site of a shoulder arthroplasty (n = 39), other (non-arthroplasty) shoulder surgery (n = 8), or primary shoulder infection without previous surgery (n = 6). All patients were followed up from spacer placement to second-stage revision to shoulder arthroplasty. Ten patients retained the spacers and were followed up for a minimum of 1 year. Results: No complications were associated with implantation of the spacers. Of the 44 patients (50 spacers) who underwent a second-stage revision after a mean interval of 6 months (range, 2-18 months), 14 patients had 18 complications. Fourteen complications occurred between implantation and removal. The most common complication was bone erosion (6 in the glenoid and 2 in the humeral shaft). Other complications were fractures of the spacer (n = 4), spacer rotation (n = 3), and humeral fracture (n = 3). Two complications required reoperation. There were 4 spacer-related complications among the 10 patients who retained the implant (3 erosions of the humeral shaft and 1 humeral shaft fracture); none required reoperation or removal. Conclusions: Complications related to antibiotic spacers are common especially between the first and second stage of revision, and awareness of these complications is important for the treating provider.