The significance of synovial biopsy in the diagnostic workup of the low-grade periprosthetic joint infection of shoulder arthroplasty

Diagnostic Evaluation of Prosthetic Joint Infections of the Shoulder: What Does the Literature Say?

The total number of patients with a total shoulder arthroplasty (TSA) is increasing, and the number of patients experiencing a (TSA) prosthetic joint infection (PJI) also will increase. It is important that physicians know how to identify signs of infection, know the common pathogens, and know how to work up a shoulder PJI. This publication reviewed the current literature about presenting signs and symptoms, common shoulder pathogens and how they differ from total knee and hip pathogens, and what images, tests, and procedures can aid in identification of infection.

Diagnostic arthroscopy for periprosthetic shoulder arthroplasty infections: a systematic review and meta-analysis

Background

Periprosthetic joint infection of the shoulder (PJI) is a devastating complication with a reported incidence of 1%-15.4% and is often difficult to diagnose with current diagnostic tools including serologic tests and arthrocentesis. This systematic review evaluates the reliability and validity of arthroscopic biopsy in the current literature for the diagnosis of shoulder PJI.

Methods

MEDLINE, Scopus, Web of Sciences, Google Scholar, and Cochrane databases were queried electronically from inception to June 2022 for publications reporting diagnostic accuracy of shoulder arthroscopic biopsy for detecting infection after anatomic total shoulder arthroplasty, shoulder hemiarthroplasty, or reverse total shoulder arthroplasty. This systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

After exclusion, our meta-analysis consisted of 7 articles with a total of 112 patients. The estimated pooled sensitivity and specificity of arthroscopic biopsy for confirmation of shoulder periprosthetic infection were 0.87 (95% confidence interval [CI]: 0.73-0.95) and 0.79 (95% CI: 0.67-0.88), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 4.15 (95% CI: 2.57, 6.70) and 0.17 (95% CI: 0.08, 0.36), respectively. The aggregate positive predictive value was 73.58% (95% CI: 63.29%-81.82%), and aggregate negative predictive value was 89.83% (95% CI: 80.59%-94.95%). The diagnostic odds ratio of arthroscopic biopsy was 19.92 (95% CI: 4.96-79.99).

Conclusion

Arthroscopic biopsy in patients suspected of shoulder PJI has good diagnostic accuracy, with high sensitivity and specificity. Given the various biopsy protocols (such as devices, numbers, locations, etc.), further prospective studies are necessary to define the future role of arthroscopic biopsy in diagnosis and treatment.

[Shoulder periprosthetic infections-what to do? : Diagnosis and treatment]

Treatment of an infected shoulder prosthesis differs significantly from other joint infections because of the unique microbiome, dominated by Cutibacterium acnes. The cause of an infection, its time of onset, the bacterial spectrum and comorbidities have to be considered for evaluation and treatment. The diagnostic workup is sometimes complex, and the recognition of a chronic and low-grade infection is often difficult because typical clinical and laboratory markers may be normal. Treatment is surgical; the therapeutic spectrum ranges from arthroscopic irrigation and open debridement with the exchange of components to one- and two-stage revisions using antibiotic-loaded spacers. Early detection and a targeted, appropriate therapy are crucial to avoid extensive soft tissue and bone damage.