Questions raised over vertebroplasty for osteo fractures

Medical Tribune September 2009 P12
David Brill

Vertebroplasty performs no better than a placebo procedure for treating painful osteoporotic fractures, two major new studies have found.

Despite its widespread usage and recommendation in guidelines, vertebroplasty did not relieve pain, alleviate disability or improve quality of life compared to sham interventions, US and Australian researchers reported.

The studies are the first true randomized controlled trials to assess a procedure which has become a firmly established treatment for osteoporotic fractures. The number of vertebroplasties performed in the US, for example, almost doubled from 2001 to 2005. [JAMA 2007 Oct 17;298(15):1760-2]

The jury is still out as to how the findings will influence practice, according to an orthopedics expert whose editorial accompanies the papers in the New England Journal of Medicine. [2009 Aug 6;361(6):619-21]

“Although the trials by Kallmes et al. and Buchbinder et al. provide the best available scientific evidence for an informed choice, it remains to be seen whether there will be a paradigm shift in the treatment of vertebral compression fractures with vertebroplasty or similar procedures,” wrote Dr. James Weinstein, chair of the department of orthopedic surgery at Dartmouth-Hitchcock Medical Center, US.

Given the rise in the number of vertebroplasties and the questionable risk-benefit ratio, it is now essential that patients be well informed about the procedure, added Weinstein.

“When faced with several choices for which the evidence is less than clear, patients and doctors must thoroughly review the options together. Informed choice helps to educate patients about treatment options and allows them to recognize that a decision can be based on their values and preferences,” he wrote.

The larger of the two trials, led by Dr. David Kallmes of the Mayo Clinic, Rochester, US, followed 131 patients with osteoporotic vertebral compression fractures. They received either vertebroplasty or a simulation procedure in which cement was not injected into vertebrae. [N Engl J Med 2009;361:569-79.]

At 1 month there was no difference between groups on a pain scale ranking intensity from 0 to 10 (difference 0.7; 95% CI -0.3 to 1.7; P=0.19) or on the Roland-Morris Disability Questionnaire (difference 0.7; 95% CI -1.3 to 2.8; P=0.49). There was however a non-significant trend for more patients in the vertebroplasty group to report clinically meaningful improvements in pain (64 percent versus 48 percent; P=0.06).

Patients were subsequently allowed to cross over and receive the other intervention – still unaware of which they had already received. At 3 months, this option had been taken up by more control patients than vertebroplasty patients (43 percent versus 12 percent), but all patients who crossed over reported comparable or worse outcomes than those who received only the first intervention.

The second trial, led by Dr. Rachelle Buchbinder of Monash University, Australia, reported 6-month follow-up of 35 vertebroplasties and 36 placebo interventions. [N Engl J Med 2009 Aug 6;361(6):557-68]

Both interventions did relieve pain but to a comparable extent: at 3 months, the mean reductions (also measured on a 10-point scale) were 2.6 in the vertebroplasty group and 1.9 in the control group (adjusted between-group difference 0.6; 95% CI -0.7 to 1.8). This difference was also not significant at 1 week or 1 or 6 months; nor was there anything nothing to choose between groups on a range of secondary outcomes, including physical functioning and quality of life.

“It has been argued that performing a randomized, placebo-controlled trial of vertebroplasty is unnecessary and unethical in view of the published results of numerous studies that suggest a benefit of vertebroplasty. Our results show – not for the first time – the hazards of relying on the results of uncontrolled or poorly controlled studies to assess treatment efficacy,” the authors wrote.

Heel ultrasound predicts osteoporotic fracture risk

Medical Tribune August 2008 P5
David Brill

A simple formula combining clinical information with quantitative ultrasound data from the heel can be used to predict whether a woman is at risk for osteoporotic fractures, a study has shown.

The prediction rule, which assigns patients a risk score from 0 to 14, was tested in 6,174 Swiss women aged 70 to 85 who were followed up for 2.8 years.

Rates of osteoporotic fracture were 6.1 percent among women defined as high-risk and 1.8 for those defined as low-risk, when using a cut-off score of 4.5. The sensitivity of the formula using this score was 90 percent.

“The whole idea of this study was to end up with a tool that can be used by primary care physicians on a daily basis,” said Dr. Idris Guessous, lead author of the study which was published in Radiology.

Ultrasound is inexpensive and portable, he added, and could be used as a diagnostic screening tool in countries where costly bone mineral density (BMD) scans are not available. Resource-permitting, the two modalities could be used in combination for select high-risk women he said.

Dr. Lau Tang Ching – consultant rheumatologist at Tan Tock Seng Hospital, Singapore – said that ultrasound could be useful for assessing nursing home patients who would have difficulty visiting hospital for a BMD scan.

He added, however, that he would like to have seen the authors report the continuous score spectrum for fracture risk prediction, rather than using the single cut-off point of 4.5.

“It would also be good if the test characteristics of the ultrasound machine were compared with dual X-ray absorptiometry BMD or with other well established predictors of low BMD such as the Osteoporosis Self-Assessment Test,” said Lau.

The researchers used a quantitative ultrasound device which requires an operator to position the subject’s foot in a water bath. The measurement procedure is otherwise automatic.

“What is really specific to this study is the way that clinical risk factors – history of fractures or recent fall – are combined with this ultrasound technique, so there are two domains that are included in the score,” said Guessous, who is a senior research fellow at Lausanne University Hospital in Switzerland.

“I stress this point because this score may not only highlight the quality of the bone itself, which is a major risk factor for fractures, but it also highlights the risk of fall for a woman.

“Depending on which factors the woman is at risk for you may better target your intervention, so eventually women who are at more risk of falling than having a bad quality of bone may end up having other interventions like hip protectors or rebalancing techniques, than just receiving bisphosphonate drugs,” he said.

Diagnosing and managing osteoporosis in primary care

Medical Tribune August 2008 P15-16

Osteoporosis affects around a third of women aged 60 – 70 and two thirds of those aged 80 and above. The condition also affects men – approximately one in five of whom will suffer an osteoporosis-related fracture above the age of 50. Osteoporosis carries a significant burden in terms of hospitalization for fractures, and patients will typically experience increased morbidity, disability, and a reduction in independence.

Diagnosis

Osteoporosis is a silent epidemic, and overt signs are usually absent until a patient presents with a fracture. This is likely to be a fragility fracture caused by relatively low trauma – a sign that the bones have become weakened. Compression fractures of the vertebrae are a common presentation, while other types include Colles’ fractures of the wrist and hip fractures, both of which typically result from a fall.

There are several risk factors for osteoporosis that general practitioners (GPs) should be aware of, such as increasing age, frailty, a personal history of fractures and a family history of fractures (particularly on the maternal side). Loss of height is also common among patients, and suggests that the vertebrae are collapsing. Back pain may also be present – often signifying that the patient has an undiagnosed compression fracture.

It should also be noted that osteoporosis in men tends to have a later age of onset than in women. Consequently mortality from fractures is twice as high for men, so it is important that GPs retain a high suspicion for osteoporosis among their elderly male patients.

GPs can also encourage their elderly patients to use the Osteoporosis Self-Assessment Tool for Asians, which is applicable for post-menopausal women of Asian descent. This can help to identify patients at high risk, who can then visit their doctor for screening and further assessment.

The gold standard for diagnosis of osteoporosis is a bone mineral density (BMD) scan using dual energy x-ray absorptiometry, with osteoporosis defined as a T-score of minus 2.5 or lower. In the absence of any other cause, a fragility fracture can also be considered as a diagnosis for osteoporosis. Patients should also receive the relevant x-rays to fully document their fractures. It can be challenging for GPs to pinpoint osteoporosis in patients who have not experienced a fracture, as some patients might find the cost of the tests prohibitive. Access to BMD scanners can sometimes be problematic

Practice Guidelines

The Ministry of Health (MOH) in Singapore is currently revising its guidelines for osteoporosis, which were last published in 2002. The new version is expected to be available later this year. The Academy of Medicine of Malaysia also has its own guidelines for osteoporosis, the second edition of which was released in 2002.

Various guidelines and recommendations are also available from the International Osteoporosis Foundation (IOF) website, including IOF-endorsed guidelines published in 2008 by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). This comprehensive 30-page document covers the diagnosis and management of the condition in postmenopausal women.

Recommendations and other helpful documents for the secondary prevention of osteoporosis are available from the National Institute for Health and Clinical Excellence (NICE), UK.

Treatment

There are many factors to consider when treating osteoporosis, and it is important to decide carefully on an appropriate strategy for each patient before proceeding with treatment.
Drug treatments are available but the cumulative costs can be formidable. The first decision physicians should take after making a definite diagnosis of osteoporosis, therefore, is whether or not to treat the patient. This decision should be based on the patient’s 10-year fracture risk, which can be calculated using IOF guidelines. A 65-year old at low fracture risk, for example, might not warrant the same treatment approach as a high-risk 85-year-old. In some cases it may be best to postpone treatment following diagnosis, monitor the patient closely and review the decision at a later stage.

Before initiating drug therapy it is important to obtain a BMD scan. This will provide a baseline value for comparisons, so that the long-term efficacy of therapy can be monitored.

Bisphosphonates, such as alendronate and risedronate, are the first-line therapy for patients who do merit drug treatment. Doctors should make their patients aware that these drugs must be taken according to certain instructions. Tablets should be taken on an empty stomach first thing in the morning, and the patient should refrain from eating for an hour afterwards or consuming any caffeine-containing drinks or milk products in this time. Failure to do so can render the tablet ineffective – which may be an explanation in cases where BMD is not improving. Elderly patients may also forget to take the drugs, or take them but forget that they have done so and lie down shortly after, which can cause painful esophagitis.

Other drug treatments include strontium ranelate, raloxifene and parathyroid hormone injections (such as teriparatide).. Annual injections of zoledronic acid, a form of bisphosphonate, have also been shown to reduce the risk of fractures and the data in support of this option are promising. The injection can be expensive, however, and some patients might prefer treatments that spread the cost out over the year.

GPs should prescribe calcium supplements for patients who are deficient, which can be a common problem in Asian countries where dairy consumption is low. The recommended intake at different ages can be found in the guidelines. Boosting calcium levels can also serve as a prevention strategy, and GPs should also encourage the use of supplements in non-osteoporotic elderly patients who are at high risk.

Lifestyle management is also a key aspect of treating osteoporosis in the primary care setting. Ill-health can lower general nutrition, leading to further reductions in calcium levels, so a healthy diet should be promoted for all cases. Osteoporotic patients should be advised not to drink or smoke, and should also be encouraged to perform weight-bearing exercises at least three times per week for 50 – 60 minutes at a time in order to improve strength and co-ordination and reduce bone loss.

Disease management tools

Elderly patients living in the community have a roughly 30 percent chance of falling in a year, and fall prevention strategies are an important tool for reducing the risk of fractures among those with osteoporosis.

Falls typically result from a combination of several underlying causes. Risk factors such as poor gait, eyesight, and neurological comorbidities should be addressed where possible, which may require collaboration between different medical disciplines. Psychologically-altering medications such as antipsychotics and sleeping tablets can also increase the risk of falls, and may need to be adjusted accordingly.

Physicians may also need to consult with occupational therapists and physiotherapists, and in some cases might choose to encourage patients to make modifications to their home environment. Suggestions can include improving lighting, anchoring carpets and rugs, securing loose wires and applying non-slip mats to stairs and bathroom floors.

Further information on osteoporosis and home care solutions can usually be obtained from specialist centers and clinics, and GPs should refer their patients onwards for further advice and treatment where appropriate.

Conclusion

Managing osteoporosis in the primary care setting begins with an accurate diagnosis. GPs should remain vigilant for patients who have a history of fragility fractures or falls, and remember that men are also at risk for the condition. Once osteoporosis is identified, doctors should choose carefully from the range of available treatment options and select the strategy that is best suited to the patient.