Atraumatic intracapsular neck of femur fractures after prolonged bisphosphonate treatment: a new atypical variant?

Abstract

SummaryWe present 2 cases of elderly females presenting with atraumatic, near-vertical (Pauwells grade 3), intracapsular neck of femur fractures. Following diagnosis of osteoporosis on DEXA scans, they had received alendronic acid for 7 and 10 years respectively. Routine blood tests and serum estimations of calcium, vitamin-D and thyroidstimulating hormone, done at admission, were within the normal ranges. These patients were managed with a hemiarthroplasty and a dynamic hip screw (DHS) respectively, following discontinuation of bisphos phonates. We present these 2 cases in light of emerging evidence that associates long-term bisphosphonate use with atypical low energy femoral fractures. Only subtrochanteric/diaphyseal fractures have been reported to date. We present a new variant of atypical femoral neck fractures in metaphyseal bone related to prolonged bisphosphonate therapy.

Atraumatic femoral neck fracture during bisphosphonate treatment: case report and review of the literature

“…Several cases of such fractures were reported to date. Previous reports described patients treated with different BPs—alendronic acid (three patients), cyclical etidronate (one patient) and one with ibandronic acid similar to the patient in this study [ 11 – 14 ]. Although treatment with BPs is highly recommended and commonly prescribed for osteoporosis to reduce the risk of hip fracture, preceding case reports show that it may also provoke femoral neck fracture.…”

“…All of the non-traumatic femoral neck fractures associated with BPs treatment were only described in women aged over 77 [ 11 – 14 ]. This is because BPs are mostly prescribed in older patients (our patient was only 57).…”

“…Prodromal pain was present in all cases in the groin area without any histories of falling. In the anamnesis, there was no evidence of excessive physical activity (in relation to age) [ 11 – 14 ]. Most patient had no comorbidities, routine blood tests were within normal range as well as levels of vitamin D and parathyroid hormone [ 11 – 14 ].…”

The enigma of atypical femoral fractures

“… 10 , 11 Furthermore, some authors have suggested that manifestation is also possible in the intracapsular part of the femur neck. 12 …”

Successive Ipsilateral Atypical Fractures of the Left Femoral Neck and the Diaphysis: Case Report and Review of the Literature

“…Elderly hip fractures until now have been considered as "typical" [5] of fragility arising from osteoporosis but the stress basicervical fractures of the femoral neck, secondary to the prolonged use of bisphosphonates, have been reported since 2002 [24][25][26][27][28] and today this "atypical" variant has been reported in four opportunities one of them bilateral [24] . The basicervical fracture of our case is like one presented by two of these authors [25,26] the others correspond to the classic description of fractures of the femoral neck due to stress [27,28] .…”