Ankylosing hyperostosis [Forestier], lumbar region

This code represents diffuse idiopathic skeletal hyperostosis (DISH), specifically affecting the lumbar spine. It is characterized by the ossification of ligaments and entheses, primarily along the anterior longitudinal ligament, leading to stiffness and reduced range of motion in the lower back. This condition is non-inflammatory and distinct from ankylosing spondylitis.

Use this code when documentation confirms a diagnosis of Forestier's disease localized to the lumbar region. This typically involves radiographic evidence of flowing ossification along the anterior aspects of at least four contiguous vertebral bodies in the lumbar spine, without significant degenerative disc disease or sacroiliac joint involvement.

• Ensure documentation specifies "lumbar region" to differentiate from other spinal segments.
• Do not confuse with ankylosing spondylitis (M45.-), which is an inflammatory condition with different diagnostic criteria.
• Look for terms like "Forestier's disease," "DISH," or "diffuse idiopathic skeletal hyperostosis" in the lumbar spine.