A chronic inflammatory arthritis primarily affecting the axial skeleton (spine and sacroiliac joints), causing pain, stiffness, and potential fusion. A form of spondyloarthritis. Strong association with HLA-B27. Onset typically in young adulthood.

• 1Clinical criteria (ASAS)
• 2X-rays of sacroiliac joints
• 3MRI of sacroiliac joints and spine
• 4HLA-B27 testing
• 5Blood tests (ESR, CRP)
• 6Assessment for uveitis
• 7Assessment for IBD

Good functional outcome with early anti-TNF therapy. Disease-modifying therapy slows radiographic progression. 10-20% have severe disability with spinal fusion. Uveitis affects 30-40%; usually responsive to topical steroids. Cardiac involvement (aortitis) rare but serious. Osteoporosis common in spine; fracture risk increased. Regular exercise maintains mobility. Biologic therapy has transformed outcomes; 70-80% achieve ASAS40 response. Smoking cessation important. Spinal surgery rarely needed.

• No primary prevention
• Early diagnosis and treatment
• Regular exercise
• Smoking cessation
• Good posture
• Ergonomic workplace
• Screening for associated conditions