Ten years of experience with elbow native joint arthritis: a multicenter retrospective cohort study

Background: Elbow native joint septic arthritis (NJSA) is a rare condition, constituting 6 %-9 % of all native septic arthritis cases. It is associated with elevated mortality and morbidity. This study aims to clarify the characteristics, management, and outcomes of elbow NJSA. Methods: We retrospectively analyzed adults diagnosed with elbow NJSA who underwent surgical intervention at Mayo Clinic facilities from January 2012 to December 2021. Diagnosis relied on clinical presentation, synovial fluid white blood cell (WBC) count, and aspiration or operative cultures. Results: Among 557 patients with NJSA during the study time frame, 19 (3.4 %) were found to have elbow NJSA. The median age of these patients was 64 years. Joint aspirations were conducted in 16 cases (84.2 %). The median synovial fluid WBC count was 43 139 cells mm^-3. Crystals were observed in three patients (15.8 %). Synovial fluid and operative tissue samples revealed 12.5 % and 20 % positive Gram stains, mostly indicating Gram-positive cocci clusters. Open arthrotomy (72.2 %) was the predominant surgical approach, and three patients (16.7 %) required reoperation within 90 d. The median antimicrobial therapy duration was 30 d (interquartile range: 22-44 d). Non-tuberculosis mycobacterium (NTM) was detected in two patients, with a treatment duration of 274 and 374 d, respectively. Complications included joint contracture and joint resection. Conclusions: Elbow NJSA is an infrequent condition associated with significant complications, such as the necessity for reoperation. Although the synovial fluid WBC count, crystals, and Gram stain positivity were less helpful for diagnosis in this study, positive Gram stain and culture results from operative tissue specimens demonstrated greater effectiveness in diagnosing elbow NJSA.