Men's Osteoporosis Support GroupAtypical spontaneous femoral shaft fractures Age Ageing. 2009 Jun 25. [Epub ahead of print]. Spontaneous femoral shaft fracture after long-term alendronate. Ali T, Jay RH. PMID: 19556326. This is a case report of a spontaneous femoral shaft fracture in an elderly woman taking Fosamax. There have been several such fractures reported in the literature, almost totally related to elderly individuals who have taken Fosamax for an extended time. I have reported on this topic in a previous Update. There is also an Update with a New York Times article linked to it that you can read. I will also list some additional literature reports on this topic for your information. J Orthop Trauma. 2008 May-Jun;22(5):346-50. Low-energy femoral shaft fractures associated with alendronate use. Neviaser AS and others. PMID: 18448990. This study involves 25 low-energy fracture patients who were treated with Fosamax (alendronate) before their fractures. Nineteen patients had a simple, transverse fracture with a unicortical break in an area of cortical hypertrophy. Only one patient not taking alendronate showed this fracture pattern. Those showing this fracture pattern had an average time of taking alendronate of 6.9 years versus 2.5 years for those taking alendronate without an atypical fracture. The authors concluded, "Low-energy fractures of the femoral shaft with a simple, transverse pattern and hypertrophy of the diaphyseal cortex are associated with alendronate use. This may result from propagation of a stress fracture whose repair is retarded by diminished osteoclast activity and impaired microdamage repair resulting from its prolonged use." Editor's comments. The average age of individuals in this study was 74.7 years with 59 females and 11 males. It doesn't say how many of the atypical fractures were in males. The association with long-term alendronate use and this unusual fracture is 98%, meaning it is virtually a certainty that alendronate is in some way causal. Most likely this is due to it overly suppressing osteoclast activity and thus preventing normal bone turnover. This suppressed bone turnover then doesn't allow for repair of microdamage to the bone, thus heightening the risk for an atypical fracture. J Clin Endocrinol Metab. 2008 Aug;93(8):2948-52. Epub 2008 Jun 3. Severely suppressed bone turnover and atypical skeletal fragility. Visekruna M and others. PMID: 18522980. This is a three-subject case report of atypical skeletal fractures. In these individuals the authors suggest that concomitant usage of glucocorticoids, hormone replacement therapy, and raloxifene, along with alendronate, led to over suppression of bone turnover, leading to what is called severely suppressed bone turnover (SSBT). Editor's comments. These three cases of SSBT are suggestive that multiple simultaneous osteoporosis therapies might lead to excessive suppression of bone turnover. Other authors have suggested that some individuals need nothing more than bisphosphonate therapy to overly suppress their bone turnover. Future research will undoubtedly lead to more answers to this problem. In the mean time those of us on long-term bisphosphonates, with or without other approved osteoporosis medications, would be wise to have our physicians monitor our bone turnover status with occasional biochemical markers of bone turnover, such as NTx or CTx. Additionally, after extended periods on a bisphosphonate, especially if your bone mineral density (BMD) has returned to the normal range, you may want to discuss either taking a "holiday" from the bisphosphonate, or going on a reduced dosage as a maintenance therapy. As long as you are occasionally monitoring your BMD via dual-energy X-ray absorptiometry (DXA), this should be all right. I repeat that you would want to discuss such options with your physician while mentioning these studies as to the cause of your concern. I also suggest that you read the Related Articles that are present on the right side of PubMed abstracts that discuss these atypical fractures. I've not listed all of the articles that discuss this condition in this Update. J Bone Miner Res. 2009 Jun;24(6):1095-102. Subtrochanteric and diaphyseal femur fractures in patients treated with alendronate: a register-based national cohort study. Abrahamsen B, Eiken P, Eastell R. PMID: 19113931. This Danish retrospective two-part study presents an opposing view to the above articles. One study was cross-sectional involving 11,944 individuals that compared the age distribution, exposure, and trauma mechanisms for different types of proximal femur fractures. Another matched cohort study tested the hypothesis that the increase in the risk of subsequent atypical femur fractures exceeded the increase in typical hip fractures. They found that 7% of both atypical and typical hip fracture patients had taken alendronate. High adherence to taking alendronate actually decreased the risk of fractures. Additionally the ratio between hip and atypical femur fractures was identical in alendronate-treated patients and the control cohort. The authors concluded, "Subtrochanteric/diaphyseal femur fractures share the epidemiology and treatment response of classical hip fractures and are best classified as osteoporotic fractures." Editor's comments. So this retrospective study found no association with long-term use of alendronate and atypical femur fractures, which is in complete opposition to the findings in the three articles above. It involved two very large databases of fracture patients, and thus has to be given credence. Until this entire issue is clarified by further research it is probably wise to discuss all the options with your physician as described in my comments above. Hopefully we will learn about this topic soon as more research clarifies the source of these atypical fractures and their risk if on long-term alendronate therapy.
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