Location of fractures and the characteristics of patients with atypical femoral fractures: analyses of 38 Japanese cases

• Published in: Journal of bone and mineral metabolism 2017-03, Vol.35 (2), p.209-214
• Main Authors: Hyodo, Kojiro, Nishino, Tomofumi, Kamada, Hiroshi, Nozawa, Daisuke, Mishima, Hajime, Yamazaki, Masashi
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alendronate - adverse effects; Alendronate - therapeutic use; Asian Continental Ancestry Group; Bone Density Conservation Agents - adverse effects; Bone Density Conservation Agents - therapeutic use; Bone Remodeling; Diphosphonates - adverse effects; Diphosphonates - therapeutic use; Female; Femoral Fractures - diagnosis; Femoral Fractures - pathology; Femur - pathology; Glucocorticoids - adverse effects; Glucocorticoids - therapeutic use; Humans; Imidazoles - adverse effects; Imidazoles - therapeutic use; Japan; Male; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Original Article; Orthopedics; Proton Pump Inhibitors - adverse effects; Proton Pump Inhibitors - therapeutic use; Retrospective Studies; Risedronate Sodium - adverse effects; Risedronate Sodium - therapeutic use
• ISSN: 0914-8779; 1435-5604
• DOI: 10.1007/s00774-016-0747-x

The purpose of this study was to determine fracture location and the characteristics of patients with atypical femoral fractures (AFFs). We studied 38 AFFs in 34 patients admitted to our institution between November 2007 and July 2013. The diagnostic criteria for the AFFs were based on 2014 American Society of Bone and Mineral Research guidelines. We classified the fracture location as proximal, middle, or distal to trisect the femoral diaphysis from just distal to the lesser trochanter to just proximal to the supracondylar flare. Bowing was defined as a line through the inside of the tip of the great trochanter and a condylar center that was outside the medullary cavity. We investigated the fracture’s location, existence of coronal bowing, and bisphosphonates (BPs), glucocorticoids (GCs), and proton pump inhibitors therapy. We analyzed associations between fracture location and demographic and clinical factors. Twelve fractures were proximal, 25 were middle, and one was distal. Nineteen limbs showed femoral bowing. Thirty-one patients received BP treatment—20 patients received alendronic acid, eight risedronic acid, and three minodronic acid. Fourteen patients received a GC, and 16 received a proton pump inhibitor. There was a significant association between coronal bowing and middle fracture locations, GC therapy and proximal fracture locations, and older age and middle fracture locations. Tall height and heavy weight had an association with proximal fracture location, and short height and light weight had an association with middle fracture location. In conclusion, we provide evidence supporting a causal relationship between BP-related severely suppressed bone turnover and AFFs. We also provide evidence supporting additional influences from altered distribution of mechanical stress with femoral bowing and various factors, such as GC therapy, age, body weight, and height, which might negatively affect bone intensity and quality and result in fracture.