Spacers for life: high mortality rate associated with definitive treatment of shoulder periprosthetic infection with permanent antibiotic spacer.

Background: Periprosthetic joint infection following shoulder arthroplasty represents a challenging problem for orthopedic surgeons. Although recent studies have supported 2-stage exchanges, this treatment choice may not be appropriate for all patients. Definitive antibiotic spacer placement represents one treatment strategy with limited reported outcomes in the literature. The purpose of this study was to investigate the mortality rate and functional outcomes associated with definitive spacer placement.

Methods: A retrospective chart review identified 17 patients who were treated with definitive antibiotic spacer placement (18 spacers) and were followed up for a minimum of 2 years after surgery. The mortality rate over the study period was determined. Demographic information, clinical course, patient-reported outcomes (American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score, and Veterans RAND 12 [VR-12] score), infection parameters as defined by International Consensus Meeting criteria, radiographic evaluation findings, and rotator cuff integrity at the time of spacer placement were collected.

Results: Seventeen patients underwent treatment with retained antibiotic spacers at a mean age of 62.4 years (range, 50-73 years). Ten patients were women, and the mean body mass index was 30.5 (range, 22.9-39.9). Spacer placement occurred at a mean of 6.1 years (range, 0.48-14.9 years) following index arthroplasty. Five patients required spacer exchange. The most common organisms were Cutibacterium acnes (6) and methicillin-sensitive Staphylococcus aureus (6); in addition, methicillin-resistant S aureus (2), coagulase-negative Staphylococcus (2), Serratia marcescens (1), gram-positive cocci (1), Enterobacter faecalis (1), Enterobacter cloacae (1), diphtheroids (1), and an infection with negative culture findings (1) were observed. The mortality rate was 52.9% (9 of 17 patients). Among the 8 surviving patients, the mean American Shoulder and Elbow Surgeons score was 33.9 (range, 13.3-80.0), the mean Single Assessment Numeric Evaluation score was 35.6 (range, 0.0-80.0), the mean VR-12 mental score was 57.2 (range, 36.6-66.9), and the mean VR-12 physical score was 37.1 (range, 21.7-64.0) at a mean of 4.7 years (range, 2.0-8.8 years).

Conclusion: Definitive antibiotic spacer placement is an acceptable method to treat infection in medically frail patients who have a high mortality risk. Spacer exchange may be necessary because of persistent infection, and functional results are poor.