M45-M49: Spondylopathies

M45: Ankylosing spondylitis

Ankylosing spondylitis, categorized under ICD-10 code M45, is a type of arthritis that mostly affects the spine, but can also affect other joints. It primarily impacts the joints and ligaments of the spine, causing inflammation resulting in chronic, severe pain and discomfort. Over time, this inflammation can lead to a complete fusion of the vertebrae, a process known as ankylosis, which leads to a lack of flexibility and often results in a hunched-forward posture. Early symptoms typically include back pain and stiffness, often worse in the mornings or following periods of inactivity. The cause of Ankylosing spondylitis is largely unknown, but genetic factors play a significant role – most individuals with the condition possess a gene known as HLA-B27. The disease usually begins in early adulthood (between the ages of 20 and 30), with men being more frequently affected than women.