Question

A 27-year-old individual presents with chronic lower back pain that improves with physical activity and is associated with early morning stiffness. There is a past history of anterior uveitis. A recent X-ray of the sacroiliac joints appears normal. What is the most appropriate next step in evaluation?

• A. MRI of the sacroiliac joints
• B. Anti-CCP antibody testing
• C. Repeat plain radiograph
• D. CT scan of the sacroiliac joints

Hint:

Early axial spondyloarthritis with normal X-ray = do MRI sacroiliac joints.

Answer 1

The Correct Option is A

Concept: Inflammatory back pain with morning stiffness and improvement with activity suggests axial spondyloarthritis. Anterior uveitis is a common extra-articular feature. MRI detects early sacroiliitis before X-ray changes appear.

Step 1: Identify inflammatory back pain.
The symptoms are: \[ \text{Morning stiffness + improvement with exercise} \] This pattern suggests inflammatory back pain.

Step 2: Connect with associated feature.
Anterior uveitis is commonly associated with ankylosing spondylitis or axial spondyloarthritis.

Step 3: Choose best investigation.
If X-ray is normal but suspicion remains high, the best next test is: \[ \text{MRI of sacroiliac joints} \] Therefore, the correct answer is MRI of the sacroiliac joints.