AB1525 THE PRESENCE OF POWER DOPPLER SIGNALS IN THE DELTOID LIGAMENT, ESPECIALLY WITH A BROAD AND DEEP DISTRIBUTION, MAY PROVIDE DIAGNOSTIC CLUES FOR SPONDYLOARTHRITIS, PARTICULARLY UNDIFFERENTIATED SPONDYLOARTHRITIS

Background Power Doppler (PD) signals are occasionally detected in the deltoid ligament on musculoskeletal ultrasound (MSUS) examination of symptomatic ankles nontraumatic inflammatory rheumatic diseases. However, it is often neglected due to its unclear clinical significance. Objectives To evaluate significance PD by MSUS Methods We reviewed record examined Japanese Red Cross Medical Center between April 2015 and October 2022. characteristics medical information images cases which power were observed ligament. Patients with only a few punctate or less excluded. traumatic degenerative disorders also Results more than 31 cases. The disease categories diagnoses patients as follows: 13 spondyloarthritis (SpA) (9 undifferentiated SpA (USpA), 2 psoriatic arthritis, reactive arthritis), 10 rheumatoid arthritis (RA) (6 early RA, 4 established RA), 7 crystal-induced (CIA) gout, 1 CPPD), primary Sjögren’s syndrome. All met ASAS criteria for peripheral all RA fulfilled 2010 ACR/EULAR classification criteria. In cases, tended distribute widely deep layer (broad distribution, out cases), while they be predominant outer surface (superficial cases). There was significant difference signal distribution pattern Fisher’s exact test (p=0.0397). CIA patients, hyperechoic materials Conclusion According literature reports, considered relatively rare Japan, where HLA-B27 positivity rate < 0.3%, an estimated population prevalence 0.01% [1] . Japan 0.65% [2] , similar rest world. Considering each disease, we speculate that characteristic SpA. presence ligament, especially broad may provide diagnostic clues SpA, particularly USpA. References [1]Hukuda S, et al. Spondyloarthropathies Japan: nationwide questionnaire survey performed Ankylosing Spondylitis Society. J Rheumatol. 2001 Mar;28(3):554-9. [2]Nakajima A, Prevalence age-stratified trends treatment, based National Database Health Insurance Claims Specific Checkups Japan. Int Rheum Dis. 2020 Dec;23(12):1676-1684. Table 1. Disease category & diagnosis Number our Estimated reported Distribution superficial Spondyloarthritis *Ref1 3 Undifferentiated 9 Psoriatic Reactive Rheumatoid *Ref2 Crystal-induced 6 Gout CPPD Acknowledgements: NIL. Disclosure Interests None Declared.