M45.8

Clinical Causes: Genetic predisposition, especially the presence of the HLA-B27 gene Environmental factors, such as infections that may trigger immune responses Immune system malfunctions leading to inflammation of spinal and pelvic joints Potential environmental or lifestyle factors that may influence disease progression

Key Symptoms: Lower back pain that worsens with rest and improves with activity Stiffness in the lower back and hips, especially in the morning or after periods of inactivity Reduced flexibility in the back and pelvis Pain radiating to the buttocks or thighs Postural changes, such as forward stooping in advanced stages Fatigue and occasional eye inflammation

Diagnosis Path: Medical history assessment focusing on symptoms and family history Physical examination to assess flexibility, posture, and tenderness Imaging studies like X-rays or MRI scans to identify joint inflammation and bone changes in the sacral and sacrococcygeal area Blood tests to detect HLA-B27 gene presence and markers of inflammation such as elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)

Treatment Protocols: Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and decrease inflammation Physical therapy aimed at maintaining flexibility, posture, and spinal mobility Regular exercise programs tailored to individual needs In severe cases, biologic medications such as tumor necrosis factor (TNF) inhibitors or interleukin blockers Lifestyle modifications including smoking cessation and maintaining a healthy weight Monitoring disease progression with routine medical follow-up