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World J Orthop. Sep 18, 2021; 12(9): 660-671
Published online Sep 18, 2021. doi: 10.5312/wjo.v12.i9.660
Current concepts in the management of bisphosphonate associated atypical femoral fractures
Branavan Rudran, Jonathan Super, Rajan Jandoo, Victor Babu, Soosai Nathan, Edward Ibrahim, Anatole Vilhelm Wiik
Branavan Rudran, Rajan Jandoo, Victor Babu, Soosai Nathan, Edward Ibrahim, Anatole Vilhelm Wiik, Department of Orthopaedic Surgery, Chelsea and Westminster NHS Trust, London TW7 6AF, United Kingdom
Branavan Rudran, Jonathan Super, The MSk Lab, Imperial College London, London W12 0BZ, United Kingdom
Anatole Vilhelm Wiik, Department of Surgery and Cancer, Charing Cross Hospital, London W6 8RF, United Kingdom
Author contributions: All authors were involved in the write up of this review.
Conflict-of-interest statement: There are no conflicts of interest from the contributing authors.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Anatole Vilhelm Wiik, BSc, MBBS, MD, Doctor, Lecturer, Department of Surgery and Cancer, Charing Cross Hospital, Fulham Palace Road, 7th Floor East Wing, London W6 8RF, United Kingdom. a.wiik@imperial.ac.uk
Received: February 25, 2021
Peer-review started: February 25, 2021
First decision: May 3, 2021
Revised: May 21, 2021
Accepted: August 5, 2021
Article in press: August 5, 2021
Published online: September 18, 2021
Abstract

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 appropriately 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 co-morbid 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.

Keywords: Bisphosphonates, Atypical fracture, Surgical fixation, Atypical femoral fracture, Osteoporosis

Core Tip: Bisphosphates are a class of drugs used as the mainstay of treatment for osteoporosis. A number of the clinical and radiological features of atypical femoral fractures and osteoporotic femoral fractures are different, 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. Currently there is no established treatment guidelines for either complete or incomplete fractures. The evidence suggests that cephalomedullary nailing of the fracture has lower revision rates.