The Clinical Classification and Surgical Techniques of Ankylosing Spondylitis (AS)

Different levels of pathological changes in the involved hip of ankylosing spondylitis patients result in different function damages and varying joint deformities, which can influence the surgical decision of hip replacement. Whether these patients have spinal deformity, the location or severity of spinal deformity also can influence the surgical decision. Therefore based on the severity of spinal deformity, we made a new classification of ankylosing spondylitis with hip involvement with or without spinal deformity, which would benefit us to make the preoperative plan and select surgical techniques.