Clinical:
- A 59 years old lady
- Presented with left lumbar pain
- No history of trauma
- Clinically: no neurological deficit
- Per abdomen: no mass palpable
Radiographic findings:
- KUB radiograph performed to look for urolithiasis
- Sclerotic changes at both sacroiliac joints margin (yellow arrows)
- Bilateral but asymmetrical; worse on the right side
- Narrowing of joint spaces
- No fusion of the joint is seen
- No obvious soft tissue mass density seen
- No periosteal reaction
Diagnosis: Bilateral sacroiliatis
Causes of bilateral sacroiliatis (asymmetrical):
- Gout
- Psoriathic arthritis
- Reactive arthritis (Reiter syndrome)
- Osteoarthritis
- Relapsing polychondritis
- Behcet disease
- Sacroiliitis circumscripta
Causes of bilateral sacroiliatis (symmetrical):
- Enteropathic arthritis
- Crohn disease
- Ulcerative colitis
- Ankylosing spondylitis
- Rheumatoid arthritis
- Hyperparathyroidism (pseudo sacroiliitis
- Osteitis condensans ilii
- Multicentric reticulohistiocytosis
- Whipple disease
Grading of sacroiliatis:
- Grade 0: normal
- Grade 1: some blurring of the joints margin; suspicious
- Grade II: minimal sclerosis with some erosion
- Grade III:
- Definite sclerosis on both sides
- Severe erosions with widening of joint spaces with or without anklylosis
- Grade IV: complete ankylosis
