Bone and Soft-Tissue Disorders
Prevalence: 2% of population
Cause: chronic stress ← instability of pubic symphysis
Age: young multiparous women
- associated with low back pain when instability of pubic symphysis present
- triangular area of sclerosis along inferior anterior aspect of ileum adjacent to SI joint (joint space uninvolved)
- similar triangle of reparative bone on sacral side
- usually bilateral + symmetric; occasionally unilateral
- sclerosis dissolves in 3–20 years following stabilization of pubic symphysis
DDx:
- Ankylosing spondylitis (affects ilium + sacrum, joint space narrowing, involvement of other bones)
- Rheumatoid arthritis (asymmetric, joint destruction)
- Paget disease (thickened trabecular pattern)