Ankylosis is fusion of a joint so it no longer moves. It can be bony (bones grow together) or fibrous (thick scar tissue locks the joint). In advanced ankylosing spondylitis the spinal vertebrae can fuse into a rigid 'bamboo spine' visible on X-ray. Early diagnosis, exercise-based physiotherapy and modern biologics have dramatically reduced how often this end-stage picture develops in the UK.
What is ankylosis?
Ankylosis: Ankylosis is stiffening or fusion of a joint, either bony (in ankylosing spondylitis) or fibrous. Untreated inflammation and immobility promote it. Prevention through medication and exercise is far more effective than reversal.
Last updated 2026-07-04. This is general information, not a substitute for personalised medical advice.