Skip to main content

by Dr. David Borenstein M.D. updated 08/21

Ankylosing spondylitis (AS) is an inflammatory spinal disease which is associated with damage to the axial skeleton including the sacroiliac joints, the lumbar, thoracic, and cervical spine. Inflammation in these areas of the spine results in changes in the tissues that is identifiable with ordinary x-ray studies. For example, plain radiographs of the sacroiliac joints (SI) in AS patients may show whitening of the bone (sclerosis), joint erosion, or in its final stages, joint fusion. In the very earliest stages of the illness, inflammation is present, but has not caused enough damage to be noticeable with regular radiographs. At this early stage of disease, joint inflammation is characterized by swelling in the bone marrow located near the edges of the joint and is identified by MRI. The question exists to whether these MRI changes are specific to AS or can be seen in other medical conditions.

Pregnancy and delivery has a remarkable effect on SI joints. A study was completed examining post-partum women at 10 days, 6 and 12 months after delivery. Thirty-five women underwent MRI investigations at those time intervals. Seventy-seven% of subjects (27/35) had sacroiliac bone marrow edema (BME) within 2 weeks of delivery. At 6 months, 46% (15/33) had BME. At 1 year, 12% (4/33) had BME. However, few structural lesions like joint erosions were noted in the post-partum group.

Back pain is a common complaint in a majority of women during pregnancy. Pain was not correlated with the presence of BMO.

This study suggests that MRI scans should be done 6 months or longer after delivery if sacroiliitis is suspected. Criteria for the diagnosis of sacroiliitis may need to be modified to include joint damage such as erosion to be considered an inflammatory lesion associated with AS. Without this change in definition, women with mechanical changes in the pelvis may be inaccurately diagnosed with an inflammatory arthritis like AS. The result will be the use of expensive therapy like biologics which would have no benefit.

Scroll to Continue

RECOMMENDED ARTICLES

shutterstock_1182421333

Lumbar Spinal Stenosis: Symptoms And Surgical Treatment Options

If you constantly suffer from leg or lower back pain, or sciatica, you may have lumbar spinal stenosis.

shutterstock_570625726

Taltz Improves Arthritis of the Spine Progression

Long-term Ixekizumab (Taltz) reduces/prevents Radiographic Axial Spondyloarthritis Progression

shutterstock_1481955044

Acute Anterior Uveitis (AAU) & Chronic Low Back Pain

Acute Anterior Uveitis (AAU) and Chronic low back pain (CBP) EQUAL Ankylosing Spondylitis (AS)

References:

1 Renson T et al. High prevalence of spondyloarthritris-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child, and birth characteristics http://dx.doi.org/10.1136/annrheumdis-2020-217095