Prosthetic shoulder infection is the most common reason for revision arthroplasty within two years of the index procedure. Due to the preponderance of indolent and slow-growing infection in shoulder arthroplasty, establishing a diagnosis of infection prior to revision shoulder arthroplasty can be extremely difficult. The aim of this study was to determine the association between specific clinical symptoms and signs as well as nuclear imaging results with culture positive status in revision shoulder arthroplasty. This study is a secondary analysis of a multicenter prospective cohort study involving four sites and 69 patients who underwent revision shoulder arthroplasty. The cohort was 60% female with a mean age of 64 years (range 36–83 years). Outcomes of interest included pre-operative specific clinical symptoms (pain at rest, fevers, chills and sweats); and white blood cell (WBC) nuclear scan results. At least five synovial tissue biopsies from separate regions in the shoulder were obtained intra-operatively during revision surgery. Twenty-three percent of patients (n=16) had confirmed culture positive infections based on the open biopsies. Sixty-four percent of patients presented with pain at rest. Pain at rest (p=0.37), chills (p=0.42), and sweats (p=0.11) were not associated with infection status. Fever was not reported by any patients in the cohort. There was no association between infection status and ESR (p=0.52), CRP (0.11), or WBC (p=0.34). No patients in the cohort had a positive WBC nuclear scan. This study suggests that specific clinical symptoms including pain at rest, systemic symptoms including fevers, chills, or sweats, and WBC bone scan are poorly associated with the presence of infection in revision shoulder arthroplasty. These findings point to the need for novel testing methods to establish the presence of infection in this patient population.
Bassi et al. (Wed,) studied this question.