- Paper of the Week: Spacers for life: high mortality rate associated with definitive treatment of shoulder periprosthetic infection with permanent antibiotic spacer
Alexander J. Rondon, MD, MBA, Taylor Paziuk, MD, Michael J. Gutman, BA, Gerald R. Williams Jr, MD, Surena Namdari, MD, MSc
Journal of Shoulder and Elbow Surgery 30(12): e732, 2021
Summary by Justin A. Magnuson, MD
Prosthetic joint infection (PJI) following shoulder arthroplasty has been reported to occur at rates ranging from 1.1% to 3.8%, with an incidence of up to 15.4% after revision . There is currently no accepted gold standard for treatment. Options include irrigation and debridement, one-stage revision, two-stage revision, and treatment with permanent antibiotic spacers. Definitive treatment with antibiotic spacers has been described in patients with severe medical comorbidities who are unable or unwilling to undergo two-stage exchange, although there is little evidence regarding outcomes [2, 3].
Rondon et al. reviewed a series of patients of 17 patients (18 shoulders) treated definitively with antibiotic spacers for chronic PJI over an 18-year period. They investigated clinical course, mortality, and functional outcomes. Patient reported outcomes included the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), and Veterans RAND 12 (VR-12). Infection was defined using the 2018 International Consensus Meeting definition . Patients underwent index arthroplasty (hemiarthroplasty, total, or reverse) for multiple indications, including osteoarthritis, proximal humeral fracture, or rotator cuff tear. Cutibacterium acnes and methicillin-sensitive Staphylococcus aureus were the most common pathogens. Spacers consisted of stemmed pin or stemless ball constructs depending on the extent of humeral bone loss.
Compared to patients treated with two-stage revision, patients undergoing permanent spacer placement were significantly older and had higher mean Charlson Comorbidity Index scores. Spacer placement occurred at a mean age of 69.9 years and a mean of 6.1 years (0.5-14.9) following index arthroplasty. The investigators found a high mortality rate of 52.9%, with a mean of 1.8 years (0.2-3.2) between spacer placement and death. At minimum 2-year follow-up (2.0-8.8), of surviving patients, mean ASES score was 33.9, SANE 35.6, VR-12 mental 57.2, and VR-12 physical 37.1. Lower scores were observed in patients with more severe humeral bone loss. Five patients required spacer exchange (mean number of spacers 1.4, range 1-4), and those treated with stemmed constructs required exchange at a higher rate (60.0% vs 12.5%).
The authors concluded that patients treated with definitive spacers have a high short-term mortality rate and poor functional outcomes, with a substantial percentage requiring spacer exchange. Despite the high complication rate and suboptimal patient reported outcomes, definitive spacers may be indicated in certain patients due to medical fragility or poor bone stock. Limitations of the study included the small sample size and heterogeneity of arthroplasty indication, medical comorbidities, and bone stock.
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