ARTICLE IN BRIEF
Investigators reported that the risk of hip fracture within the first three months post-stroke was 3.4 times higher than expected and it dropped to a two-fold risk over the first year. There was a five-fold increased risk in patients under 70.
Doctors caring for patients on the heels of a stroke should beware of an increased risk for hip and femur fractures, according to a new study published Aug. 6 online in advance of the October print edition of Stroke.
Frank de Vries, PhD, assistant professor of pharmacoepidemiology at the University of Utrecht, Netherlands, and his colleagues the University of Southampton in the United Kingdom, analyzed patient records from tens of thousands of patients and controls from Dutch medical registries and found a two-fold increase in hip/femur fractures in patients who had experienced a stroke in the preceding three months to one year.
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The study supports smaller studies that have found a similar association between stroke and fractures but no one ever studied such a large cohort of patients and tracked the time course of their elevated risk.
“Our findings imply that it is important to conduct fracture risk assessment immediately after a patient is hospitalized for stroke,” said Dr. de Vries and his colleagues in the paper. “Fall prevention programs, bone mineral density measurements, and the use of biophosphonates (bone-protecting drugs) may be necessary to minimize hip fractures in the elderly during and following stroke rehabilitation.”
After a stroke, neurologists should still focus on the prevention of a second stroke, he added. But they should be aware of a new problem: the hip fracture.
The investigators reviewed charts on 6,763 patients who are part of a Dutch registry called PHARMO Record Linking System, and 26,341 controls. The patient group was identified from medical records showing they had a hip or femur fracture. Through a linked nationwide hospital discharge registry, they identified 225 people (3.3 percent) who had a stroke within a few years of the fracture compared to 407 (1.5 percent) in the controls.
The risk of hip fracture within the first three months was 3.4 times higher than expected and it dropped to a two-fold risk over the first year. There was a five-fold increased risk in patients under 70.
Dr. De Vries said that another randomized trial in Japanese stroke survivors showed that administration of a bisphosphonate drug decreased hip fracture risk after 18 months. He said that neurologists should prescribe physical exercise as soon as possible after a stroke and recommend footwear with stable heels and anti-slip soles.
Falling might also occur because of diminishing vision following a stroke, so doctors should have the patient's eyesight evaluated. Also, medicines that work on the CNS should be evaluated for their increased risk of triggering falls.
Dr. de Vries said that the rate of bone loss in the first year after a stroke is higher than that observed in post-menopausal women. Some studies have shown a rapid loss of bone mineral density up to 14 percent in the first year. What's more, partial paralysis has been associated with an increased risk of falls.
REASONS FOR INCREASED RISK
The question is why? According to Dr. de Vries and others who study co-morbidities among older people, stroke has been associated with a drop in bone mineral density in the weakened limb. Patients who are getting their mobility back may be at increased risk for falls, and thus fractures, if they are walking on weakened legs.
“The most severe stroke patients may be bed-bound or in a wheelchair and thus their risk is less than someone who is moving about again,” said Heather Whitson, MD, a geriatrician at the Center for the Study of Aging at Duke University Medical Center, who was not involved with the study. “This study highlights a point for possible prevention,” she added.
In a 2006 study in the Journal of the American Geriatrics Society, Dr. Whitson and her colleagues examined data from large cohort of stroke patients from two large Veterans Administration registries — the VA Acute Stroke, including 1,073 veterans admitted to VA hospitals between April 1995 and March 1997, and the Integrated Stroke Outcomes Database, with 6,578 veterans who received inpatient rehabilitation for stroke at 121 VA facilities during fiscal years 2001 and 2002. They reported a three- to six-fold higher risk for subsequent fractures depending on the populations they studied.
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“Neurologists need to think about the implications of the diseases outside of their specialty,” she said. “We need to break out of the single disease paradigm and think about how one disease may put people at risk for other conditions. This is a perfect example.”
“There are no effective interventions to prevent mortality after hip fracture,” said Dr. de Vries. “The best way forward is probably to save one's life by preventing hip fractures.”
GUIDELINES FOR REDUCING THE RISK FOR FALLS
The AAN Quality Standards Subcommittee published evidence-based guidelines for interventions that can reduce the risk of falls in the Feb. 5 issue of Neurology. (Also, see Neurology Today's “AAN Practice Guidelines: Neurologists Can Take Simple Steps to Reduce Fall Injuries” (Feb. 7, 2008; www.neurotodayonline.com).
• Pouwels S, Lalmohamed A, de Vries F, et al. Risk of hip/femur fracture after stroke: A population-based case-control study. Stroke
2009; E-pub 2009 Aug. 6.
• Whitson HE, Pieper CF, Lyles KW, et al. Adding injury to insult: fracture risk after stroke in veterans. J Am Geriatr Soc 2006;54(7):1082–1088.
• Thurman DJ, Stevens JA, Rao JK. Practice Parameter: Assessing patients in a neurology practice for risk of falls (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2008;70:473–479.
©2009 American Academy of Neurology