M45.0

Clinical Causes: Genetic predisposition, especially the presence of the HLA-B27 gene Autoimmune response where the immune system mistakenly attacks spinal tissues Environmental factors that may trigger or exacerbate inflammation Secondary factors such as infections that might influence disease onset

Key Symptoms: Chronic pain and stiffness in the lower back and hips, especially in the morning or after periods of inactivity Tenderness along the spine that may worsen with physical activity Reduced flexibility leading to a hunched-forward posture Persistent fatigue and sometimes fever Enthesitis — inflammation where tendons or ligaments attach to bones, commonly at the pelvis, heels, or along the spine In some cases, inflammation can also involve other joints or organs, leading to additional symptoms

Diagnosis Path: Diagnosis of ankylosing spondylitis involving multiple spinal sites requires a combination of clinical evaluation, medical history, imaging studies, and laboratory tests. Key diagnostic approaches include: - Physical examination to assess spinal mobility and areas of tenderness - X-rays to detect characteristic changes like vertebral fusion, osteoporosis, or joint inflammation - MRI scans for early detection of inflammation before structural changes occur - Blood tests to check for markers of inflammation, such as elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), and the presence of HLA-B27 gene - Exclusion of other causes of back pain and spinal stiffness

Treatment Protocols: While there is currently no cure for ankylosing spondylitis, several treatments aim to relieve symptoms, improve posture, and prevent complications: - Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation - Physical therapy and exercises to maintain spinal flexibility and posture - Regular physical activity to strengthen muscles supporting the spine - Disease-modifying antirheumatic drugs (DMARDs) and biologic agents for controlling severe inflammation - Pain management strategies including heat therapy or assistive devices - In some cases, surgical intervention may be necessary to address significant joint damage or deformities Early diagnosis and proper management are essential in helping individuals maintain their quality of life and prevent severe complications related to spine fusion and deformity.