Axial radiographic pattern and morphology in PsSpA (n=118) and AS (n=157) cases
| PsSpA | AS | AS versus PsSpA | |||
|---|---|---|---|---|---|
| n (%) | n (%) | OR | 95% CI | p Value | |
| Pattern | |||||
| Radiographic | |||||
| Sacroiliitis | 79 (67) | 157 (100) | – | – | – |
| Spondylitis (cervical and/or lumbar) | 84 (71) | 109 (69) | 0.94 | 0.52 to 1.69 | 0.83 |
| Sacroiliitis pattern | |||||
| Bilateral | 65/79 (82) | 142/147 (97) | 6.14 | 2.08 to 18.15 | 0.001 |
| Symmetrical grade | 60/79 (76) | 119/147 (81) | 1.17 | 0.59 to 2.32 | 0.65 |
| Spondylitis pattern | |||||
| Cervical vertebrae | 52/116 (45) | 85 (54) | 1.20 | 0.65 to 2.25 | 0.56 |
| Cervical facet joint | 29 (25) | 60 (38) | 1.48 | 0.81 to 2.72 | 0.20 |
| Lumbar vertebrae | 50/117 (43) | 85 (54) | 1.37 | 0.75 to 2.50 | 0.30 |
| Morphology | |||||
| Sacroiliac joint | |||||
| Sclerosis bilaterally (grade 2) | 6 (5) | 9 (6) | 1.75 | 0.56 to 5.48 | 0.34 |
| Erosion (grade 3) | 42 (36) | 53 (34) | 1.07 | 0.63 to 1.81 | 0.80 |
| Partial ankylosis (grade 3) | 25 (21) | 46 (29) | 1.08 | 0.56 to 2.10 | 0.81 |
| Complete ankylosis (grade 4) | 18 (15) | 68 (43) | 2.96 | 1.42 to 6.15 | 0.004 |
| Vertebral | |||||
| Erosion, n (%) | 3 (3) | 6 (4) | 1.58 | 0.38 to 6.57 | 0.53 |
| Non-bridging syndesmophyte | 47 (40) | 58 (37) | 0.93 | 0.57 to 1.56 | 0.79 |
| Bridging syndesmophyte | 12 (10) | 36 (23) | 2.78 | 1.49 to 5.18 | 0.001 |
*Multivariate reverse-stepwise logistic regression model (adjusted as required for the following potential covariates: sex, age at radiographic assessment, disease duration at radiographic assessment, HLA-B*27 status, anti-TNF use ever, synthetic DMARD use ever, smoking and BMI).
Anti-TNF, antitumour necrosis factor; AS, ankylosing spondylitis; BMI, body mass index; DMARD, disease modifying antirheumatic drug; PsSpA, psoriatic spondyloarthritis.