Characteristics of Post-traumatic-spondyloarthritis: A Cross-sectional Study from a Single Tertiary Hospital

Objective. Trauma has been proposed as a triggering factor of psoriatic arthritis (PsA), and the deep Koebner phenomenon was the suggested underlying mechanism. The relationship between spondyloarthritis (SpA) and trauma was only observed in PsA. This study investigated cases of SpA other than PsA that occurred after physical trauma and analyzed their clinical, laboratory, and radiologic features. Methods. We retrospectively reviewed the medical records of 213 patients who visited our hospital due to a suspicion of SpA and grouped them into post-traumatic-SpA (PT-SpA, n=12) and non-post-traumatic-SpA (non-PT-SpA, n=201). Baseline characteristics were compared between the two groups by cross-sectional manner. Results. Peripheral SpA was more common in PT-SpA than in non-PT-SpA. Active inflammation on sacroiliac joint (SIJ) magnetic resonance imaging (MRI) was more common in non-PT-SpA (83.5% vs. 54.5%, p=0.046). The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) was significantly higher in the non-PT-SpA group (2.0 vs. 0.0, p=0.007). Symptom duration from the first SpA symptom to diagnosis tends to be longer in the non-PT-SpA group (2.0 vs. 0.5 years, p=0.079). Conclusion. PT-SpA patients more frequently showed peripheral SpA, a less active inflammatory lesion on SIJ MRI, and a lower mSASSS score. Further studies are needed to clarify whether physical trauma has a direct/indirect role in the pathogenesis of SpA or merely confers an opportunity to recognize SpA symptoms.