Ab0708 Use of Ultrasound for the Diagnosis of Arthritis in the Cricothyroid Joint in Rheumatoid Arthritis Patients

Background: Rheumatoid Arthritis (RA) is the most prevalent inflammatory arthropathy, affecting around 1% of the population. As a systemic granulomatous disease, RA commonly targets diarthrodial joints, leading to early inflammatory changes and potential permanent damage. While the disease traditionally affects small joints symmetrically, laryngeal joints, including the cricoarytenoid and cricothyroid joints, can also be impacted. Objectives: This study aims to evaluate the utility of ultrasound as a diagnostic tool for assessing laryngeal joints, specifically focusing on the cricothyroid joint, in patients with Rheumatoid Arthritis (RA). Methods: A proof-of-concept study was conducted, assessing 20 Rheumatoid Arthritis (RA) patients. They underwent screening for symptomatic laryngeal involvement through a survey, excluding other causes. Patients were categorized as having "oropharyngeal clinical involvement due to the disease" if they presented two or more of the following symptoms: "change in voice tone," "hoarseness," "odynophagia," "pain while speaking," "feeling of a foreign body in the throat," "dry cough," and "otalgia." All participants underwent ultrasound examination of the cricothyroid joint using a MINDRAY TE-7 ultrasound machine with a linear probe operating at a frequency between 6 and 13 MHz, including power Doppler mode. The OMERACT criteria were applied for assessing the presence of synovitis or Doppler signals. Results: Twenty Rheumatoid Arthritis (RA) patients (16 females, 80%) from the Rheumatology Department at the Central Hospital of Defense Gómez Ulla, treated between June and September 2023, were analysed. The mean age was 56.45 years (range: 35 to 70), with an average follow-up duration of 5.75 years. Nineteen patients were rheumatoid factor positive, and 12 were anti-citrullinated protein antibody (ACPA) positive. Twenty-five percent presented erosions. Nineteen were on treatment with Methotrexate, leflunomide, or salazopyrin, and three were undergoing biological treatment. Three patients were smokers, and three had thyroid pathology. Disease activity was assessed using the Clinical Disease Activity Index (CDAI), with a mean CDAI of 10.7 (range: 3 to 48). All patients underwent a screening questionnaire for Laryngeal Symptomatology due to the disease. Symptoms were positive in nine patients and negative in eleven. Among positive patients, eight had OMERACT scores of 1 or higher, while among asymptomatic patients, three had an OMERACT score of 1, and the rest were negative on ultrasound. In our sample, despite limitations due to the small number of patients, we found a sensitivity of 0.88 and specificity of 0.72 for ultrasound as a diagnostic tool for Synovitis secondary to Rheumatoid Arthritis in the cricothyroid joint. Conclusion: In our sample, musculoskeletal ultrasound has proven to be an effective tool for diagnosing synovitis in the cricothyroid joint in Rheumatoid Arthritis (RA) patients. However, given the limited number of patients included in the sample, further confirmation through subsequent studies is warranted. REFERENCES: [1] Voulgari P V., Papazisi D, Bai M, Zagorianakou P, Assimakopoulos D, Drosos AA. Laryngeal involvement in rheumatoid arthritis. Vol. 25, Rheumatology International. 2005. p. 321-5. [2] Izuka S, Kaneko S, Harada T, Sakai H, Takahashi Y, Yamashita H, et al. Cricoarytenoid arthritis in rheumatoid arthritis. Rheumatology (Oxford). 2 de agosto de 2021;60(8):3955. [3] Lofgren RHM, Montgomery WWM. Incidence of laryngeal involvement in rheumatoid arthritis. N Engl J Med. 1962; July 26:193-5. Acknowledgements: NIL. Disclosure of Interests: None declared.