Hip Morphometry of Femoroacetabular Impingement Pattern in Patients with Ankylosing Spondylitis

Abstract

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial skeleton with involvement of peripheral joints and non-articular structures (1). Indeed, it is best known for its symptom of lower back pain; however, patients often present with hip or groin pain misleading the clinician to think that the cause lies primarily in the hips. Hip involvement as a common problem in AS increases the burden and negative affects its prognosis of AS than any other axial joints (2). Femoroacetabular impingement (FAI) has been recently identified as a major cause of early primary osteoarthritis (OA) of the hip (3). FAI refers to abnormal contact between the femoral head-neck junction or the acetabular rim (4). A number of predisposing conditions have been described with deformities of the femur and the acetabulum which result in FAI including Legg-Calve-Perthes, slipped capital femoral epiphysis, coxa magna, hip dysplasia, and fractures of the femoral neck (5). Though FAI has not been recognized as a common radiologic feature of AS, we noticed FAI like features in hips of AS patients and hypothesized that AS may be predisposed to FAI. To the best of our knowledge, there has been no study about FAI patHip Morphometry of Femoroacetabular Impingement Pattern in Patients with Ankylosing Spondylitis 강직성척추염 환자에서 대퇴비구충돌증후군 고관절 모양에 관한 연구