Sacroiliac Joint Lesion X-Ray Grading

Grading		Specific Content
Grade 0	Normal	Normal
Grade I	Suspicious
Grade II	Mild Abnormality	Localized erosion, sclerosis, no change in joint space
Grade III	Moderate Sacroiliitis	Joint erosion, narrowed space, or localized fusion
Grade IV	Severe Abnormality	Joint space disappearance, sacroiliac joint ankylosis

Explanation

X-ray examination of the sacroiliac joint has diagnostic significance for spondyloarthritis; typical sacroiliitis may present as blurred joint surfaces, increased subchondral bone density, bone erosion, and cystic changes. As the condition progresses, joint space narrowing or even fusion may occur.

References

Wang Jiyao, ed. "Internal Medicine" (Eight-Year System) [M]. People's Health Publishing House. 2005