Abstract Background/Aims Juvenile idiopathic arthritis (JIA) is the most common rheumatological condition present in children under 16 years of age. Tenosynovitis remains an under-recognised manifestation of JIA and is not accounted for in the International League of Associations for Rheumatology (ILAR) classification of JIA. Tenosynovitis is especially common in joints like the ankles and, if untreated, can cause structural damage and physical impairment. This study aims to highlight the significance of imaging in the identification of ankle tenosynovitis in JIA patients. This is achieved by determining the prevalence of tenosynovitis on imaging, quantifying the detection rates of magnetic resonance imaging (MRI) and ultrasound scan (USS), and locating the affected tendons. Methods A retrospective study was conducted at Nottingham Children’s Hospital, a paediatric rheumatology centre. The study included confirmed JIA patients presenting with ankle pain or swelling who had undergone imaging in a five-year period between January 2020 and December 2024. All ankle USS and MRI reports ordered by paediatric rheumatology consultants were retrieved by the Picture Archiving and Communication System team. Patient demographics, clinical symptoms, and findings of tenosynovitis or synovitis, including affected tendons, were extracted from radiology referrals and reports. Results 22 patients (14 females and 8 males, average age 12.0 years, range 5-17 years) underwent imaging, with 36 ankles scanned. Tenosynovitis was identified in 9 patients (41%) and in 12 ankles (33%). Of 16 ankles assessed with MRI, tenosynovitis was detected in 9 ankles (56%), and synovitis was observed in 5 ankles (31.2%), with 3 ankles (18.8%) exhibiting both tenosynovitis and synovitis. Ultrasound was performed on 20 ankles, in which tenosynovitis was detected in 3 ankles (15%), and synovitis was detected in 1 ankle (5%); none demonstrated both pathologies together. In all 12 ankles with tenosynovitis, the tibialis posterior was affected, followed by the peroneal tendons in 7 ankles and the flexor tendons in 6 ankles. In 9 ankles (75%) presenting with tenosynovitis, multiple tendons were affected simultaneously. Conclusion This study confirms that tenosynovitis is a significant contributor to ankle symptoms in JIA patients, sometimes affecting multiple tendons. While the prevalence was greater on MRI than USS, this is likely due to patient population selection, as more severe cases underwent MRI. Acknowledging coexisting tenosynovitis is clinically significant, particularly in oligoarticular JIA patients, where intra-articular steroid injections may resolve synovitis but not tenosynovitis. Management of tenosynovitis would involve a short course of steroids, with escalation to methotrexate/biologic therapy if unresponsive. Hence, clinical examination alone is insufficient to identify tenosynovitis, and imaging should be regarded as essential in both diagnosis and guiding appropriate treatment. Therefore, clinicians should maintain a high index of suspicion and a low threshold for imaging to ensure timely and effective management of tenosynovitis. Disclosure F.S. Varghese: None. S. Deepak: None. K.C. Warrier: None. S. Rangaraj: None. K. Gargh: None.
Varghese et al. (Wed,) studied this question.