Table 2.

Grading of radiographic sacroiliitis (4).

Grade	Definition or radiographic changes
0	Normal
1	Suspicious changes
2	Minimal abnormalities: small localized areas with erosion and sclerosis, without alteration in the joint width
3	Unequivocal abnormality: moderate or advanced sacroiliitis with 1 or more signs of erosions, sclerosis, widening, joint space narrowing, or partial ankylosis
4	Severe changes: total ankylosis