Ankylosing spondylitis - ischial enthesophytes

Case contributed by Jerry Jiang


Back stiffness. HLA B-27 positive.

Patient Data

Age: 55 years
Gender: Male

Ossifications of paravertebral ligaments seen, compatible with syndesmophytes and causing the bamboo spine appearance. Ossification of intervertebral discs also demonstrated. 

Syndesmophytes are seen in the lumbar spine in conjunction with ankylosis of the bilateral sacroiliac joint. Enthesophyte formation at the bilateral ischial tuberosities. Mild bilateral hip joint space narrowing without erosions.

Case Discussion

Symptoms started at age 25 but the patient was not diagnosed with ankylosing spondylitis until years later after progression of the disease. Failed treatment with etanercept; symptoms well-controlled on adalimumab and methotrexate. Plain films demonstrate classic vertebral findings of ankylosing spondylitis in addition to ischial enthesophyte formation (enthesophytosis) likely from ossification at the origin of the hamstrings.


This case was submitted with supervision and input from:

Soni C. Chawla, M.D.
Associate Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Olive View - UCLA Medical Center

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