ReXSPA scales.
| Proliferation, from PsA Ratingen Score | Erosion, from Sharp/van der Heijde | Joint Space Narrowing, from Sharp/van der Heijde |
|---|---|---|
| 0 = normal | 0 = no erosions | 0 = normal |
| 1 = bony proliferation measured from the original bone surface of 1–2 mm, or clearly identifiable bone growth not exceeding 25% of the original diameter of the bone | 1= discrete erosion | 1 = asymmetrical minimal narrowing with loss of up to a maximum of 25% |
| 2 = bony proliferation of 2–3 mm or bone growth between 25% to 50% | 2 = large erosion not passing the midline | 2 = definite narrowing with loss of up to 50% of the normal space |
| 3 = bony proliferation > 3 mm or bone growth 50% | 3 = large erosion passing the midline | 3 = definite narrowing with loss of 50–99% of > the normal space or subluxation |
| 4 = combination of above | 4 = absence of a joint space, presumptive evidence of ankylosis, or complete subluxation | |
| 5 = combination of above | ||
| Proliferation score/18 points | Erosion score/55 points | JSN score/44 points |
| Total score /234 |
ReXSPA: Reductive X-ray Score for Psoriatic Arthritis; PsA: psoriatic arthritis; JSN: joint space narrowing.