Management of bisphosphonate-associated subtrochanteric
fractures remains opinion- or consensus-based. There are limited
data regarding the outcomes of this fracture. We retrospectively reviewed 33 consecutive female patients with
a mean age of 67.5 years (47 to 91) who were treated surgically
between May 2004 and October 2009. The mean follow-up was 21.7 months
(0 to 53). Medical records and radiographs were reviewed to determine
the post-operative ambulatory status, time to clinical and radiological
union and post-fixation complications such as implant failure and
need for second surgery. The predominant fixation method was with an extramedullary device
in 23 patients. 25 (75%) patients were placed on wheelchair mobilisation
or no weight-bearing initially. The mean time to full weight-bearing
was 7.1 months (2.2 to 29.7). The mean time for fracture site pain
to cease was 6.2 months (1.2 to 17.1). The mean time to radiological
union was 10.0 months (2.2 to 27.5). Implant failure was seen in
seven patients (23%, 95 confidence interval (CI) 11.8 to 40.9).
Revision surgery was required in ten patients (33%, 95 CI 19.2 to
51.2). A large proportion of the patients required revision surgery
and suffered implant failure. This fracture is associated with slow
healing and prolonged post-operative immobility. Cite this article:
We carried out a retrospective review over ten months of patients who had presented with a low-energy subtrochanteric fracture. We identified 13 women of whom nine were on long-term alendronate therapy and four were not. The patients treated with alendronate were younger, with a mean age of 66.9 years (55 to 82) Our study suggests that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. We believe that this finding is important and indicates the need for caution in the long-term use of alendronate in the treatment of osteoporosis.
