Tohoku J. Exp. Med., 2017 August, 242(4)

The Incidence of Atypical Femoral Fractures in Patients with Rheumatic Disease: Yamagata Prefectural Committee of Atypical Femoral Fractures (YamaCAFe) Study

YUYA TAKAKUBO,¹ DAICHI OHTA,¹ MASAJI ISHI,² JUJI ITO,¹ HIROHARU OKI,¹ YASUSHI NAGANUMA,¹ TOMOHIRO UNO,¹ AKIKO SASAKI,¹ TAKERU AKABANE,³ KATSUYUKI DAIRAKU,⁴ SHINICHI GOTO,⁵ YASUO GOTO,⁶ YUMIKO KANAUCHI,⁷ SHINJI KOBAYASHI,⁸ TAKU NAKAJIMA,⁹ KEIJI MASUDA,¹⁰ MICHIHARU MATSUDA,¹¹ NARIYUKI MURA,¹² KENJI TAKENOUCHI,¹³ HIROYUKI TSUCHIDA,¹⁴ YASUSHI ONUMA,¹⁵ JUNICHIROU SHIBUYA,¹⁶ MITSUYOSHI SEINO,¹⁷ OSAMU YAMAGUCHI,¹⁸ KEN HIRAGAMI,¹⁴ YASUHIRO URAYAMA,¹⁹ TAKASHI FURUKAWA,¹² SHOUTA OKUDA,²⁰ KEN OGURA,²¹ TAKESHI NAKAMURA,²² KAN SASAKI,¹ TSUNEO KONTA²³ and MICHIAKI TAKAGI¹

¹Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan
²Department of Orthopaedic Surgery, Yamagata Saisei Hospital, Yamagata, Yamagata, Japan
³Department of Orthopaedic Surgery, Yamagata Prefectural Central Hospital, Yamagata, Yamagata, Japan
⁴Department of Orthopaedic Surgery, Okitama Public General Hospital, Higashiokitama-gun, Yamagata, Japan
⁵Department of Orthopaedic Surgery, Tsuruoka Municipal Shonai Hospital, Tsuruoka, Yamagata, Japan
⁶Department of Orthopaedic Surgery, Sagae City Hospital, Sagae, Yamagata, Japan
⁷Department of Orthopaedic Surgery, Yamagata Prefectural Kahoku Hospital, Nishimurayama-gun, Yamagata, Japan
⁸Department of Orthopaedic Surgery, Shiseido Hospital, Yamagata, Yamagata, Japan
⁹Department of Orthopaedic Surgery, Sanyudo Hospital, Yonezawa, Yamagata, Japan
¹⁰Department of Orthopaedic Surgery, Saiseikan Yamagata City Hospital, Yamagata, Yamagata, Japan
¹¹Department of Orthopaedic Surgery, Tohoku Central Hospital, Yamagata, Yamagata, Japan
¹²Department of Orthopaedic Surgery, Yoshioka Hospital, Tendo, Yamagata, Japan
¹³Department of Orthopaedic Surgery, Kitamurayama Hospital, Murayama, Yamagata, Japan
¹⁴Department of Orthopaedic Surgery, Miyuki Social Medical Corporation, Miyukikai Hospital, Kaminoyama, Yamagata, Japan
¹⁵Department of Orthopaedic Surgery, Yamagata Tokusyukai Hospital, Yamagata, Yamagata, Japan
¹⁶Department of Orthopaedic Surgery, Yamagata Prefectural Shinjo Hospital, Shinjo, Yamagata, Japan
¹⁷Department of Orthopaedic Surgery, Shonai Amarume Hospital, Higashitagawa-gun, Yamagata, Japan
¹⁸Department of Orthopaedic Surgery, Sinoda General Hospital, Yamagata, Yamagata, Japan
¹⁹Department of Orthopaedic Surgery, Mamurogawa Town Hospital, Mogami-gun, Yamagata, Japan
²⁰Department of Orthopaedic Surgery, Nihonkai General Hospital, Sakata, Yamagata, Japan
²¹Department of Orthopaedic Surgery, Yonezawa City Hospital, Yonezawa, Yamagata, Japan
²²Department of Orthopaedic Surgery, Funayama Hospital, Yonezawa, Yamagata, Japan
²³Department of Cardiology, Pulmonology and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan

Atypical femoral fractures (AFFs) have been reported to occur with minimal or spontaneous subtrochanteric and femoral shaft fractures with a characteristic transverse pattern, compared with typical femoral fractures in young patients with high-energy trauma. AFFs are related to long-term use of bisphosphonates (BPs), glucocorticoids and rheumatic diseases. We have estimated a blind analysis of AFFs in rheumatic patients receiving BPs and glucocorticoids ordinary over a long time in all Yamagata prefectural area through radiographic examination. The 123 AFFs including suspected cases over six years were collected and reviewed by two independent orthopedic surgeons. We found 86 patients with a total of 99 AFFs between 2009 and 2014 (1.43 cases/100,000 person/year). Of these 99 AFFs, 11 were in 8 rheumatic patients including three patients with bilateral AFFs. The incidence of AFFs in rheumatic patients had trend to increase from 2012. The mean age of all 8 patients was 54.9 years. All 8 patients received BPs and 7/8 received prednisolone (PSL). The mean dose of PSL was 14 mg/day. Compared to patients with unilateral AFFs, those with bilateral AFFs in rheumatic patients were on a higher dose of PSL (20 mg/day vs. 7 mg/day) and had less femoral neck-shaft angle (129° vs. 136°, p < 0.05). In conclusion, the incidence of AFFs in rheumatic patients showed a trend to increase from 2012 to 2014 in Yamagata prefecture. Careful management of AFFs is of particular importance in rheumatic patients who have taken high doses of PSL and have small femoral neck-shaft angle.

keywords —— atypical femoral fracture; femur; prednisolone; rheumatic disease; small femoral neck-shaft angle

© 2017 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2017, 242, 327-334

e-mail: takakubo-y@med.id.yamagata-u.ac.jp