Implant Removal and Spacer Placement for Infected Shoulder Arthroplasty: Risk Factors for Repeat Procedures, Spacer Retention, and Mortality.

Background: Current studies reporting on patients following prosthesis removal and spacer placement for periprosthetic joint infection (PJI) of the shoulder have largely been descriptive and insufficiently powered to determine risk factors for outcomes other than reimplantation.

Purpose: The objective of the present study is to provide a national perspective on the 1-year outcomes following prosthesis removal and spacer placement and risk factors for outcomes other than reimplantation for treatment of PJI following shoulder arthroplasty.

Methods: A national database was queried for Medicare patients who underwent prosthesis removal and spacer placement for PJI between 2005 and 2012. These patients were then evaluated for 5 major study endpoints including: (1) replantation of a shoulder prosthesis within 1 year postoperatively, (2) a repeat irrigation and debridement with second antibiotic spacer placement procedure within 1 year postoperatively, (3) in-hospital death within 1 year postoperatively, (4) a shoulder Girdlestone-type procedure within 1 year postoperatively, and (5) the remaining patients, who were considered to have a retained spacer. Patients with a study endpoint within 1 year postoperatively were included in the study: (1) mortality, (2) repeat debridement, (3) resection arthroplasty, and (4) reimplantation. While it is possible that some patients were not captured due to errors in coding, it is unlikely that patients were lost to follow-up due to change in location of services, given that the database captures all episodes of care that are coded throughout the USA. Independent risk factors were evaluated using logistic regression analysis.

Results: Nine hundred seventy-five patients who underwent prosthesis removal and spacer placement were included. Within 1 year postoperatively, 21 patients died (2.2%), 70 patients had a repeat debridement procedure (7.2%), 55 patients had a resection arthroplasty procedure (5.6%), 349 patients retained their spacers (35.8%), and the remaining 480 patients had a shoulder arthroplasty reimplanted (49.2%). Numerous independent risk factors exist for all outcomes studied.

Conclusion: The fate of antibiotic spacers placed for PJI of the shoulder at 1 year is variable, with numerous independent risk factors for outcomes other than reimplantation. Patients with PJI following total shoulder arthroplasty should be counseled on the risk factors that influence the outcomes of staged revision for shoulder PJI.