- Definitions of axial involvement in PsA vary widely, contributing to ongoing debates and interpretation challenges in classifying axial PsA (axPsA).
- The study included 150 patients, and 11 developed new syndesmophytes during the 2-year observation period.
- When C-reactive protein (CRP) was incorporated into the definitions, patients with chronic back pain had a 2-fold increase in the probability of syndesmophyte development, while those with inflammatory back pain had a 7-fold increase.
- Radiographic axial involvement, particularly using the radiographic sacroiliitis definition, resulted in a 3-fold higher probability of syndesmophyte development. When combined with elevated CRP, the chance increased to 14 times.
- The study contributes valuable insights into axial involvement in PsA, addressing classification challenges and the need for further research in this area.