Table 2.

ReXSPA scales.

Proliferation, from PsA Ratingen ScoreErosion, from Sharp/van der HeijdeJoint Space Narrowing, from Sharp/van der Heijde
0 = normal0 = no erosions0 = 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 bone1= discrete erosion1 = 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 midline2 = 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 midline3 = definite narrowing with loss of 50–99% of > the normal space or subluxation
4 = combination of above4 = absence of a joint space, presumptive evidence of ankylosis, or complete subluxation
5 = combination of above
Proliferation score/18 pointsErosion score/55 pointsJSN score/44 points
Total score /234
  • ReXSPA: Reductive X-ray Score for Psoriatic Arthritis; PsA: psoriatic arthritis; JSN: joint space narrowing.