Ankylosing Spondylitis (AS) is a chronic disease with inflammation at the enthesis of the spine and peripheral skeleton, which leads to bony erosion or juxtain sertional osteoporosis in the early stages.
However, in later stages, new bone formation, syndesmophytes and ankylosis can occur. Generalized as well as regional osteopaenia is common in AS  with a frequency ranging from 50-92% [2-4]. It ranges from 41–62% in spine and 46–86% in femur .
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