J Rheum Dis 2016; 23(3): 179-182  
A Case of Ischiofemoral Impingement Syndrome as a Differential Diagnosis of Ankylosing Spondylitis
Minkoo Kang1, So-Young Bang2, Jeong Ah Ryu3, Seungjun Gim1, Eun-Sik Park1, Hyeyoung Lee1, Hye-Soon Lee2
1Department of Internal Medicine, Hanyang University College of Medicine, Seoul, 2Division of Rheumatology, Department of Internal Medicine, 3Department of Radiology, Hanyang University Guri Hospital, Guri, Korea
Correspondence to: Hye-Soon Lee, Division of Rheumatology, Department of Internal Medicine, Hanyang University Guri Hospital, 153 Gyeongchun-ro, Guri 11923, Korea. E-mail:lhsberon@hanyang.ac.kr
Received: July 8, 2015; Revised: August 26, 2015; Accepted: August 27, 2015; Published online: June 30, 2016.
© Korean College of Rheumatology. All rights reserved.

This is a open Access article, which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.
Ischiofemoral impingement (IFI) syndrome is an uncommon cause of gluteal and hip pain. We report on a case of a 20-year-old man who presented with chronic gluteal and hip pain with low back pain without a history of trauma or surgery. He was misdiagnosed with ankylosing spondylitis (AS) at another clinic. The patient was finally diagnosed with IFI syndrome according to pelvic magnetic resonance imaging findings at our hospital. After two weeks of medical and physical treatment, his pain showed gradual improvement. Because IFI syndrome is rarely reported in male patients, it might be misdiagnosed as AS. Therefore, IFI syndrome should be considered as a differential diagnosis of AS, particularly in young male patients with atypical pain characteristics. (J Rheum Dis 2016;23:179-182)
Keywords: Ischiofemoral impingement syndrome, Ankylosing spondylitis

This Article