Diagnosis and Treatment of Infected Shoulder Arthroplasty: Current Concepts Review

Association between radiographic soft-tissue thickness and increased length of stay, operative time, and infection rate after reverse shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a widely performed surgical procedure to address various shoulder pathologies. Several studies have suggested that radiographic soft-tissue thickness may play a role in predicting complications after orthopedic surgery, but there have been limited studies determining the use of radiographic soft-tissue thickness in RSA. The purpose of this study was to evaluate whether radiographic soft-tissue thickness could predict clinical outcomes after RSA and compare the predictive capabilities against body mass index (BMI). We hypothesized that increased radiographic shoulder soft-tissue thickness would be a strong predictor of operative time, length of stay (LOS), and infection in elective RSA.

MATERIAL AND METHODS

A retrospective review of patients undergoing RSA at an academic institution was conducted. Preoperative radiographic images were evaluated including measurements of the radius from the humeral head center to the skin (HS), deltoid radius-to-humeral head radius ratio (DHR), deltoid size, and subcutaneous tissue size. Different correlation coefficients were used to analyze various types of relationships, and the strength of these associations was classified based on predefined boundaries. Subsequently, multivariable linear and logistic regressions were performed to determine whether HS, DHR, deltoid size, and subcutaneous tissue size could predict LOS, operative time, or infection while controlling for patient factors.

RESULTS

HS was the most influential factor in predicting both operative time and LOS after RSA, with strong associations indicated by standardized β coefficients of 0.234 for operative time and 0.432 for LOS. Subcutaneous tissue size, deltoid size, and DHR also showed stronger predictive values than BMI for both outcomes. In terms of prosthetic joint infection, HS, deltoid size, and DHR were significant predictors, with HS demonstrating the highest predictive power (Nagelkerke R2 = 0.44), whereas BMI did not show a statistically significant association with infection. Low event counts resulted in wide confidence intervals for odds ratios in the infection analysis.

CONCLUSION

Greater shoulder soft-tissue thickness as measured with concentric circles on radiographs is a strong predictor of operative time, LOS, and postoperative infection in elective primary RSA patients.

Management of periprosthetic joint infection of shoulder arthroplasty: Single-stage versus two-stage protocols. A systematic review and meta-analysis of the literature

Background

The treatment of shoulder prosthetic joint infections (PJIs) requiring removal of the prosthesis is not well defined. This article aims to systematically review and compare the results of the literature in single-stage and two-stage protocols in the treatment of shoulder PJI.

Methods

An in-depth search on PubMed/Scopus/Web of Science databases and cross-referencing search was carried out concerning the articles reporting detailed data on the topic.

Results

A total of 486 shoulder PJIs were included: 137 treated with single-stage and 349 with two-stage procedure. A similar distribution between early and not-early infections (19.1% vs 80.9%) was found between the two groups. The overall rate of success in terms of PJI eradication was significantly higher in the single-stage group (95.6% vs 85.7%, p < 0.001). The non-infection-related complications rate was 13.8% in the single-stage group and 37.6% in the two-stage group (p < 0.001), the non-infection-related revision rate was 8% and 18.9%, respectively (p = 0.005).

Discussion

The single-phase protocol showed a higher success rate in eradicating the infection and a lower complication rate. However, the low number of patients included, the low quality of the articles, the lack of data on clinical severity and bacteriological virulence suggest caution in conclusions.

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.

One- or two-stage exchange for periprosthetic shoulder infection: Systematic review and meta-analysis

INTRODUCTION

One-stage exchange is the gold-standard for management of periprosthetic shoulder infection. The present review compares efficacy between 1- and 2-stage exchange in this indication.

MATERIAL AND METHODS

We performed a systematic literature review and meta-analysis following the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) criteria. The literature search used the Medline, Embase and Central data-bases. The studies included assessed 1- and 2-stage exchange in periprosthetic shoulder infection. The main outcome was reinfection rate, and the secondary outcome postoperative complications rate.

RESULTS

Twenty-one studies, for 501 patients, were included: 5 assessing 1-stage exchange, 11 2-stage, and 5 both. Mean follow-up was 4.3 years (range, 2-6.1 years). Mean reinfection rates ranged between 0 and 50% in 1-stage exchange and between 0 and 36.8% in 2-stage exchange. The combined rate was 7% (95% CI, 3.8-12.5%) in 1-stage and 21.3% (95% CI, 16-27.9%) in 2-stage exchange. Mean complications rates ranged between 0 and 50% in 1-stage exchange and between 5.7% and 73%% in 2-stage exchange. The combined rate was 17% (95% CI, 11.9-23.9%) in 1-stage and 32.8% (95% CI, 25.8-40.6%) in 2-stage exchange.

DISCUSSION

To our knowledge, the present meta-analysis is the first to assess results in 1- and 2-stage exchange for chronic periprosthetic shoulder infection.

CONCLUSION

One-stage exchange seemed to provide better results, with less reinfection and fewer complications than 2-stage exchange.

LEVEL OF EVIDENCE

I, meta-analysis.