Surgical strategy of the treatment of atypical femoral fractures

The atypical femoral fracture(AFF)has been attracting significant attention because of its increasing incidence;additionally,its treatment is challenging from biological and mechanical aspects.Although surgery is often required to manage complete AFFs,clear guidelines for the surgical treatment of AFFs are currently sparse.We reviewed and described the surgical treatment of AFFs and the surveillance of the contralateral femur.For complete AFFs,cephalomedullary intramedullary nailing spanning the entire length of the femur can be used.Various surgical techniques to overcome the femoral bowing common in AFFs include a lateral entry point,external rotation of the nail,and the use of a nail with a small radius of curvature,or a contralateral nail.In the case of a narrow medullary canal,severe femoral bowing,or pre-existing implants,plate fixation may be considered as an alternative.For incomplete AFFs,prophylactic fixation depends on several risk factors,such as a subtrochanteric location,presence of a radiolucent line,functional pain,and condition of the contralateral femur;the same surgical principles as those in complete AFFs can be applied.Finally,once AFF is diagnosed,clinicians should recognize the increased risk of contralateral AFFs,and close surveillance of the contralateral femur is recommended.

Current concepts in the management of bisphosphonate associated atypical femoral fractures

Bisphosphonates are a class of drugs used as the mainstay of treatment for osteoporosis.Bisphosphonates function by binding to hydroxyapatite,and subsequently targeting osteoclasts by altering their ability to resorb and remodel bone.Whilst aiming to reduce the risk of fragility fractures,bisphosphonates have been associated with atypical insufficiency fractures,specifically in the femur.Atypical femoral fractures occur distal to the lesser trochanter,until the supracondylar flare.There are a number of the differing clinical and radiological features between atypical femoral fractures and osteoporotic femoral fractures,indicating that there is a distinct difference in the respective underlying pathophysiology.At the point of presentation of an atypical femoral fracture,bisphosphonate should be discontinued.This is due to the proposed inhibition of osteoclasts and apoptosis,resulting in impaired callus healing.Conservative management consists primarily of cessation of bisphosphonate therapy and partial weightbearing activity.Nutritional deficiencies should be investigated and appro-priately corrected,most notably dietary calcium and vitamin D.Currently there is no established treatment guidelines for either complete or incomplete fractures.There is agreement in the literature that nonoperative management of bisphosphonate-associated femoral fractures conveys poor outcomes.Currently,the favoured methods of surgical fixation are cephalomedullary nailing and plate fixation.Newer techniques advocate the use of both modalities as it gives the plate advantage of best reducing the fracture and compressing the lateral cortex,with the support of the intramedullary nail to stabilise an atypical fracture with increased ability to load-share,and a reduced bending moment across the fracture site.The evidence suggests that cephalomedullary nailing of the fracture has lower revision rates.However,it is important to appreciate that the anatomical location and patient factors may not always allow for this.Although causation between bisphosphonates and atypical fractures is yet to be demonstrated,there is a growing evidence base to suggest a higher incidence to atypical femoral fractures in patients who take bisphosphonates.As we encounter a growing comorbid elderly population,the prevalence of this fracture-type will likely increase.Therefore,it is imperative clinicians continue to be attentive of atypical femoral fractures and treat them effectively.