Abstract
There are reported cases of cortical reaction over the tension side of the normal femoral shafts in patients on long term treatment with alendronate, leading to subsequent femoral shaft fractures. We performed a retrospective review of patients with low-energy femoral shaft fracture on alendronate, admitted to our institution during the period 2004 to May 2009. The presence of radiological changes of cortical hypertrophy with or without Looser's zone over the tension side of the femoral bone (normal limb) was determined and correlated with clinical symptoms. Thirteen patients were identified. Average duration of alendronate use was 6.5 ± 3.3 years (ranges, two to 10 years). These radiological changes were noted in four patients. Average duration of alendronate usage in these four patients was 6.5 ± 2.4 years (ranges, 5 to10 years). Prodromal thigh pain was present in a patient, who had cortical hypertrophy with the presence of a Looser's zone traversing the cortex on the femoral shaft. One patient had Looser's zone limited at the lateral hypertrophied cortex without prodromal pain. The interobserver kappa coefficient was 0.96. A femoral radiograph should be performed in all patients who are on long-term alendronate therapy who present with thigh pain. We propose a new grading system based on our observation of the radiological features in these four cases. This new grading of the radiological spectrum of femoral shaft cortical pathology has the potential to stratify the risk of low energy femoral fracture for patients treated with long-term alendronate therapy. Femur, Cortical Hypertrophy, Looser Zone, Alendronate.
Highlights
Osteoporosis is an increasingly common health problem characterised by imbalance in the rate of bone resorption and formation, generally in conjunction with increased rate of bone turnover[1]
As described by Goh et al.[3], we too have observed the presence of cortical reaction over the tension side in the contra-lateral femur in patients treated with long-term alendronate, who presented with a femoral shaft fracture
We note the presence of low energy femoral shaft fracture in patient with osteoporosis, after prolonged exposure to potent anti-resorptive therapy such as alendronate use
Summary
Osteoporosis is an increasingly common health problem characterised by imbalance in the rate of bone resorption and formation, generally in conjunction with increased rate of bone turnover[1]. Alendronate has been the most widely used anti-resorptive agent and is recommended for the prevention and treatment of postmenopausal osteoporosis. As described by Goh et al.[3], we too have observed the presence of cortical reaction over the tension side in the contra-lateral femur (normal limb) in patients treated with long-term alendronate, who presented with a femoral shaft fracture. These abnormal radiological findings raised our interest to further evaluate the significance of these radiological cortical pathology in relation to patient clinical presentation, and subsequently develop a guideline to management of this disease
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call