Increased Risk of Atypical Hip Fractures Associated with Bisphosphonate UseSep 23, 2015
Women with osteoporosis who take bisphosphonate drugs to prevent fractures have an increased risk of atypical hip fractures, new research finds.
Javier Gorricho-Mendívil conducted the research for his PhD thesis at the NUP/UPNA-Public University of Navarre (Spain), MedicalXpress reports.
According to Gorricho-Mendívil, hip fracture is the “most common cause" of admission to hospital trauma and orthopaedics departments. Hip fractures are associated with a high rate of mortality, loss of quality of life, and significant financial costs. In 2010 in the European Union, there were about 620,000 hip fractures and the cost associated with the fractures amounted to more than 37,000 million euros.
The majority of hip fractures occur in people over 65, and they are more frequent in women. Spain has seen an increase in the population over 65 from14.92 percent in 1997 to 16.62 percent in 2008, Gorricho-Mendívil writes. The average age of women who suffer hip fractures is over 80, with fracture rates among those over 85 in excess of 20 per 1,000 inhabitants per year.
Bisphosphonates are the drugs most frequently prescribed to treat osteoporosis-Fosamax is a major brand name-but in recent years drug regulators in Spain, other European countries, and the U.S. have detected a correlation between the use of these drugs and various problems linked to correct bone regeneration, for example, osteonecrosis [bone death] of the jaw and atypical hip fractures. Doctors have recently been asked to review treatment after five years to determine whether it was appropriate to continue bisphosphonate treatment, according to MedicalXpress.
Oral bisphosphonates "have been consistently found to increase the levels of bone mineral density, and reduce vertebral fractures detected in X-rays," Gorricho-Mendívil writes. In trials using a placebo, where a proportion of the target sample was not taking any medication, the reduction in the number of hip fractures was much smaller. Gorricho-Mendívil, his thesis supervisor, Juan Erviti-López (a researcher at Navarrabiomed-Fundación Miguel Servet) and Scandinavian and Canadian researchers, have published an article about the research in the BMJ.
Gorricho-Mendívil drew his study data from the Database for Pharmaco-epidemiological Research in Primary Healthcare (BIFAP), with 4.8 million clinical records of the National Healthcare Service of Spain provided by over 18,000 doctors. Records were made anonymous so researchers could not identify individual patients. The database is designed and managed by the Spanish Agency for Drugs and Healthcare Products (AEMPS).
The study includes hip fractures in women over 65 from 2005 to 2008. The research was supported by a grant from the Spanish Ministry of Health, Social Services and Equality, MedicalXpress reports. Gorricho-Mendívil identified 2,009 women, average age, 82,with typical hip fractures and 44 with atypical fractures, those that occur in a less frequent location.
The author concludes that the use of oral bisphosphonates was not associated with a reduction in hip fractures in women over 65 but it was associated with a greater risk of atypical hip fractures (subtrochanteric or diaphyseal fractures). "This risk increases when the time exposed to bisphosphonates is increased. The longer the treatment time was, the greater the risk of atypical fracture," Gorricho-Mendívil writes in summary.