Overview of elbow arthritis, a rare involvement in patients with juvenile idiopathic arthritis

To examine the frequency, clinical progression, and treatment approaches for elbow involvement in juvenile idiopathic arthritis (JIA), emphasizing its rarity and associated management complexities. This retrospective study evaluated 1,065 patients diagnosed with JIA using the International League of Associations for Rheumatology (ILAR) criteria. Data collected included demographics, disease subtypes, clinical characteristics, laboratory results, imaging findings, and treatment modalities. Ultrasonography was performed in all patients with elbow involvement (n = 86). Statistical analyses assessed differences across subtypes and associations with treatment strategies. Of the cohort, 86 patients (8.1%) had elbow involvement, most commonly in the polyarticular subtype, and least frequently in systemic and enthesitis-related arthritis. The median age at elbow involvement was 11.6 [IQR 7.0-15.4] years, with earlier involvement significantly correlating with earlier disease onset. Females accounted for 72% of affected patients. At diagnosis, 52.3% had elbow arthritis, while 47.7% developed it during follow-up. ANA positivity (50%) was linked to increased corticosteroid (CS) use. Following elbow involvement, 53.4% initiated Conventional disease-modifying anti-rheumatic drug (cDMARDs), and 62.3% began Biologic disease-modifying anti-rheumatic drug (bDMARDs); 41.8% required a switch to another bDMARD. Ultrasonography played a key role in evaluation, and 8.1% of patients required intra-articular injections. Elbow involvement in juvenile idiopathic arthritis is an uncommon but clinically relevant manifestation, most frequently observed in polyarticular disease. Management of elbow arthritis was challenging, with many patients requiring escalation to systemic therapy, including biologic agents, despite intra-articular steroid use. This is the largest known cohort study (n = 86) to systematically investigate elbow involvement in juvenile idiopathic arthritis (JIA), addressing a major gap in the literature dominated by isolated case reports. Elbow arthritis was observed across JIA subtypes, most frequently in polyarticular disease, and could occur both at diagnosis and during follow-up. All patients with elbow involvement underwent articular ultrasonography as part of the diagnostic evaluation, with MRI used selectively in complex cases.