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

Abstract

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.

Idiopathic Osteonecrosis and Atypical Femoral Fracture in Systemic Lupus Erythematosus

“…Generally, lateral bowing of the femur is considered to be a risk factor for AFF. Hyodo et al indicated that LupusAFF located in the mid femur was signiicantly related to femoral bowing, whereas AFF in the proximal femur was related to glucocorticoid use [68]. In our previous study of patients with autoimmune diseases taking BP and glucocorticoid, the femoral beaking was mostly located at the subtrochanter, and was not related to lateral bowing of the femur [73].…”

“…However, once it occurs, it takes much time to heal [64,65], and the daily life activities of the patient are often impaired. Risk factors for AFF other than long-term BP use include glucocorticoid therapy [66,67], complicating connective tissue disease [67], lateral bowing of the femur [68,69], a low level of serum 25-hydroxyvitamin D [66], and female gender [70]. Glucocorticoid therapy has been reported to have an important impact on AFF [66,67], although no signiicant…”

Post-operative Rehabilitation of Atypical Femoral Fracture in a Single Center

“…15) In the above-mentioned six-center Japanese study, 17) nine of ten patients had a history of BP use, with a mean duration of 4.9 years (four patients had used BPs for 3-5 years, and five patients had used them for ≥5 years). A study performed at 11 centers in Japan 18) found a history of BP use in 31 of 34 AFF patients (91.2%), with a mean treatment duration of 5.1 years. In the present series, 12 of 13 AFF patients (92.3%) had a history of BP use.…”

Bone Formation Parameters of the Biopsied Ilium Differ between Subtrochanteric and Diaphyseal Atypical Femoral Fractures in Bisphosphonate-Treated Patients

“…dronate (Hyodo et al 2017). In mouse femora, minodronate accumulates in bone underneath osteoblasts rather than under osteoclasts and minodronate-coated bone matrix is resistant to osteoclastic resorption, suggesting bone-preserving effect by examining through isotope microscopy (Hongo et al 2016).…”

“…The reason for this finding remains unknown. Hyodo et al (2017) reported a significant association between coronal bowing and middle fracture locations (diaphyseal), suggesting that the femoral geometry tends to affect the risk for the incidence of diaphyseal AFFs. Sasaki et al (2012) also reported that the femoral curvature may be a causative factor for low-energy diaphyseal femoral fractures.…”