Elsevier

Injury

Volume 42, Issue 7, July 2011, Pages 702-706
Injury

Femoral shaft fractures in the elderly – Role of prior bisphosphonate therapy

https://doi.org/10.1016/j.injury.2010.12.019Get rights and content

Abstract

Introduction

There is a recent surge in interest on bisphosphonate related femoral fractures. Most studies have examined subtrochanteric fractures in patients on long-term bisphosphonates. This study evaluates the characteristics of low-impact femoral shaft fractures in elderly patients on long-term alendronate.

Materials and methods

All patients above 60 years old admitted to the National University Hospital for femoral shaft fracture from January 2003 to January 2007 were retrospectively analysed. Of the 55 patients included, 7 had prior alendronate therapy and were examined in detail.

Results

All 7 patients on prior alendronate therapy sustained their fractures by low-impact or atraumatic mechanisms of injury. 5 of these 7 patients exhibited a characteristic fracture pattern of thickened lateral cortices at the proximal fracture fragment (p < 0.05) and all 7 patients had either transverse or short oblique fractures. Notably, none of the 7 patients had bone mineral density scans prior to their fractures. One patient was started on alendronate after a vertebral compression fracture, whilst the other 6 patients were started on alendronate without any clear clinical indication. All 7 patients reported prodromal thigh pain 3 weeks to 2 years prior to the fracture.

Conclusions

Low-impact femoral shaft fractures in elderly patients on long-term alendronate therapy represent a new entity of insufficiency fractures, with characteristic low-impact modes of injury and fracture patterns on radiograph. Prodromal thigh pain is a warning sign for impending fracture in this group of patients and should be evaluated closely. Teriparatide is a possible alternative to alendronate following such a fracture though more long-term clinical studies are required.

Introduction

There has been a recent surge in interest in bisphosphonate-related fractures and a number of studies looking into the association between low-impact fractures and the use of bisphosphonates have been published.12, 18, 19, 27, 28 Odvina et al. suggested prolonged alendronate therapy as a possible cause of the low energy non-spinal fractures in her study due to suppressed bone turnover.28 Goh et al. subsequently published a retrospective report on low-impact subtrochanteric fractures in patients on long-term alendronate therapy and proposed an association between long-term alendronate use and insufficiency fractures of the femur.12 The effects of long-term bisphosphonate use on bone metabolism still remain unclear.

Femoral shaft fractures typically occur in young adult males as a result of major trauma.26, 31 In the elderly age group, such fractures are commonly pathological fractures, with a female preponderance.17, 31 The association between low-impact femoral shaft fractures and alendronate use has recently been studied by Neviaser et al.27 and Lenart et al.19 looking at characteristic fracture patterns in this group of patients.

Our study retrospectively reviewed elderly patients admitted to our hospital with femoral shaft fractures over a 4-year period with a particular focus on patients with a history of prior bisphosphonate therapy. We predicted an association between the long-term use of bisphosphonates and low-impact femoral shaft fractures.

Section snippets

Materials and methods

The study was designed as a retrospective analysis of all elderly patients (>60 years old) with femoral shaft fractures admitted to the National University Hospital, Singapore, over a 4-year period from January 2003 to January 2007. Ethical approval from the Institutional Review Board (IRB) was obtained prior to the conduct of the study. The femoral shaft was defined as the segment of the femur lying 5 cm distal to the lesser trochanter and 8 cm proximal to the adductor tubercle4 in the study.

Results

Of the 49 patients studied, 7 had been on alendronate therapy prior to the fracture. The mean duration of alendronate use was 34.3 months (range, 24–72 months). No other types of bisphosphonates were used by any of these patients. All of these patients were females. The mean age of these 7 patients was 77.3 years (range 70–94 years).

Of these 7 patients who were previously on alendronate therapy, 4 had sustained their fractures from atraumatic mechanisms of injury, whilst 3 had sustained their

Discussion

Adynamic bone disease from prolonged use of anti-resorptive drugs like alendronate has become an area of growing research interest in recent years. Alendronate has been highly successful as a first-line therapy in the treatment of postmenopausal osteoporosis, through its inhibition of osteoclastic activity which results in increased bone mineral density.1, 3 Its efficacy has been demonstrated by the Fracture Intervention Trial (FIT), a multicenter randomised controlled study, which showed that

Conclusion

In conclusion, this is a new entity of fractures seen exclusively in patients on alendronate treatment. These fractures are usually atraumatic or from low-impact trauma and X-rays show characteristic lateral cortex thickening with a beaked appearance at the site of fracture, indicative of a previous stress fracture. It is essential to rule out underlying metabolic diseases in these patients through biochemical tests and radiographic screening of the contralateral femur. Adynamic bone disease in

Conflict of interest statement

There is no conflict of interest in the conduct of this research project. None of the authors of this paper received financial or other personal benefits from the conduct and writing of this study.

References (37)

  • S. Das De et al.

    A rational approach to management of alendronate-related subtrochanteric fractures

    J Bone Joint Surg Br

    (2010)
  • H. Dobnig et al.

    Teriparatide reduces bone microdamage accumulation in postmenopausal women previously treated with alendronate

    J Bone Miner Res

    (2009)
  • B. Ettinger et al.

    Differential effects of teriparatide on BMD after treatment with raloxifene or alendronate

    J Bone Miner Res

    (2004)
  • H.A. Fleisch

    Bisphosphonates: preclinical aspects and use in osteoporosis

    Ann Med

    (1997)
  • M.S. Goddard et al.

    Atraumatic bilateral femur fracture in long-term bisphosphonate use

    Orthopedics

    (2009)
  • S.K. Goh et al.

    Subtrochanteric insufficiency fractures in patients on alendronate therapy: a caution

    J Bone Joint Surg Br

    (2007)
  • B. Jobke et al.

    Teriparatide following bisphosphonates: initial and long-term effects on microarchitecture and bone remodeling at the human iliac crest

    Connect Tissue Res

    (2009)
  • A.A. Khan et al.

    Bisphosphonate associated osteonecrosis of the jaw

    J Rheumatol

    (2009)
  • Cited by (10)

    • Outcome of intramedullary nail for fixation of osteoporotic femoral shaft fractures in the elderly above 60

      2021, Injury
      Citation Excerpt :

      Intramedullary nailing (IMN) is the preferred treatment method, appears to have comparable postoperative outcomes [1–3]. Atypical fractures may occur after long-term use of bisphosphonates and bowed femoral shaft stress fractures [1–4]. Fixation Difficulties in elderly patients are due to osteoporosis and comorbidities.

    View all citing articles on Scopus
    View full text