Bisphosphonate-Related Complete Atypical Subtrochanteric Femoral Fractures: Diagnostic Utility of Radiography

Abstract

Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures.

Healing Delayed But Generally Reliable After Bisphosphonate-associated Complete Femur Fractures Treated with IM Nails

“…We defined atypical complete femoral fractures by radiographic evidence of a transverse or short oblique fracture line, medial spike, focal lateral cortical thickening, and relative lack of comminution. Incomplete bisphosphonateassociated atypical femoral fractures were defined by radiographic evidence of focal lateral cortical thickening with or without an incomplete fracture line [25].…”

Atypical femoral fractures are a separate entity, characterized by highly specific radiographic features. A comparison of 59 cases and 218 controls

“…Rosenberg et al [11] analyzed sensitivity, specificity and accuracy of radiographic features in a case control analysis of 38 diaphyseal fractures (19 with bisphosphonate use). Their results are similar to ours, especially in terms of specificity.…”

Progression of bisphosphonate-associated impending atypical femoral fracture despite prophylactic cephalomedullary nailing: A case report and review of literature

“…6 These fractures have distinct clinical and radiological features, including prodromal pain, cortical hypertrophy and unicortical ''beaking''. 1,7,8 The recognition of these features provides opportunities for prophylactic fixation, which has been associated with a reduced rate of progression to complete fracture and reduced hospital length-of-stay. 2,3,9 The predominant hypothesis regarding the pathophysiology of atypical femur fracture is that bisphosphonate induced suppression of bone turnover leads to the accumulation of bone microdamage, a reduction in matrix heterogeneity, and an increase in advanced glycation endproducts, leading to impaired stress fracture healing, and the development of an insufficiency fracture at the point of maximal, weight-bearing stress, namely at the subtrochanteric or diaphyseal femur.…”