- Ankylosing M48.10

-- Cervical Region M48.12

-- Cervicothoracic Region M48.13

-- Lumbar Region M48.16

-- Lumbosacral Region M48.17

-- Multiple Sites M48.19

-- Occipito-atlanto-axial Region M48.11

-- Sacrococcygeal Region M48.18

-- Thoracic Region M48.14

-- Thoracolumbar Region M48.15