Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown etiology which primarily affects the sacroiliac joints, spine, hips and, less commonly, the knee joints. Ankylosing spondylitis typically affects young adults, most commonly males (M:F = 3:1) in their second through fourth decades. Hip joint involvement in AS often results in severe deformities and in combination with a stiff spine, leads to further deterioration in function. For patients with fixed kyphotic spinal deformities, hip involvement, and the subsequent development of flexion contractures limits their ability to walk and further compromises their posture leading to severe functional impairment in approximately 30% of patients.
Last date updated on January, 2021