Presentation
Low back pain and limping for 1 month following recent normal vaginal delivery
Patient Data
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Linear irregular sacral fracture sclerotic lines parallel to the sacroiliac joints with surrounding bone marrow edema exhibiting bright signals on STIR & T2 fat sat images.
Mild bilateral subarticular bone marrow edema is seen at the sacroiliac joints, more at the iliac side on the right, denoting active sacroiliitis.
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X-rays show no fracture lines.
Case Discussion
Sacral insufficiency fractures are a subtype of stress fractures occurring when normal stresses are applied to abnormal bone.
The patient had severe vitamin D deficiency, anemia, and recent normal vaginal delivery.
X-rays may be normal (as in this case).