Abstract
Introduction
Since the concept of severely suppressed bone turnover (SSBT) after long-term bisphosphonate (BPs) use, SSBT have been believed as the major cause of low-energy femoral fractures, which are called atypical femoral fractures. Here we present several cases of stress fractures with bowing femoral shaft deformity, which can be another cause of low-energy femoral fractures in the elderly.
Materials and Methods
From 1998 to 2012, we treated thirteen cases of low-energy fractures of femoral shaft. All cases were females with an average age of 77.0 (67–88) years. Retrospectively, we assessed fracture type, X-ray of contralateral side, bowing deformity of femur, and duration of BPs use.
Result
All cases were classified as simple fracture; AO/OTA type 32-A. In eleven cases, incomplete fracture of contralateral side was found by X-ray and confirmed by a bone scintigram. In twelve cases, obvious bowing deformity of the femoral shaft was noted. BPs were used only in seven cases, and the medication period was not so long. Just one case had taken Alendronate for ten years, and this case showed no bowing deformity.
Discussion
Shane defined atypical femoral fracture, and indicated that the same fractures may develop even without BPs use. According to this definition, our advocating stress fractures by bowing deformity will also be included in atypical fractures. We think stress fractures by bowing deformity should be discriminated from atypical fractures by SSBT.
