Published 5/1/2009

Second Look – Clinical News and Views

If you missed these Headline News Now items the first time around, AAOS Now gives you a second chance to review them. Headline News Now—the AAOS thrice-weekly, online update of news of interest to orthopaedic surgeons—brings you the latest on clinical, socioeconomic, and political issues, as well as important announcements from AAOS.

NSAIDs not associated with CVD mortality in RA patients
A British
study published in the Annals of the Rheumatic Diseases (March) found that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) may not be associated with increased cardiovascular disease (CVD) mortality among patients with inflammatory polyarthritis/rheumatoid arthritis (RA). Of 923 patients with newly diagnosed RA from 1990–1994, 203 patients had died by 2004; 85 deaths were due to CVD. Baseline NSAID use was inversely associated with all-cause mortality and CVD mortality. Interval NSAID use had weaker mortality associations with both all-cause mortality and CVD mortality.

Obesity not linked to progression of knee OA
Obesity is a risk factor for knee osteoarthritis (OA), according to a study published in Arthritis Care & Research (March 15). The study found no overall relationship between obesity and the progression of knee OA. Reviewing data from 2,623 participants enrolled in a longitudinal study of persons with or at high risk of knee OA, the authors found that more than 80 percent were overweight (body mass index [BMI] 25 to 30) or obese (BMI 30 to 35). At baseline, 36.4 percent of knees had tibiofemoral OA, and of those, only one third were neutrally aligned. Compared to patients with a normal body mass index, patients who were obese or very obese were at an increased risk of incident OA (relative risk 2.4 and 3.2, respectively [P for trend <0.001]). the risk extended to knees from all alignment groups. no overall association was found between a high bmi and the risk of oa progression in knees with oa at baseline. an increased risk of progression was found in knees with neutral alignment, but not in knees with varus alignment. the effect of obesity was intermediate in knees with valgus alignment.>

Greater vitamin D intake associated with fewer fractures
meta-analysis of 20 randomized, controlled trials (more than 80,000 patients) that compared oral vitamin D, with or without calcium, with calcium or placebo found that nonvertebral fracture prevention with vitamin D is dose-dependent. When the results of the trials were pooled, vitamin D supplements decreased the risk of nonvertebral fractures by 14 percent and of hip fractures by 9 percent. The pooled results of the nine trials in which participants received doses of more than 400 international units per day found that vitamin D supplements reduced nonvertebral fractures by 20 percent and hip fractures by 18 percent. Over all trials, antifracture efficacy increased significantly with a higher dose and higher achieved blood 25-hydroxyvitamin D levels for both end points. Higher doses of vitamin D reduced nonvertebral fractures in both community-dwelling individuals (–29 percent) and institutionalized older individuals (–15 percent), and its effect was independent of additional calcium supplementation. The study was published in Archives of Internal Medicine (March 23).

Lack of gravity activates osteoclasts
Osteoclasts and their precursors are direct targets for microgravity and mechanical forces, according to
research published online in the Journal of the Federation of American Societies for Experimental Biology. Scientists compared two sets of osteoclasts obtained from the bone marrow of mice femurs: one launched into space via the European Space Agency’s 2007 Foton-M3 mission, and a control set kept on Earth. Both sets of cells were maintained in custom-designed bioreactors equipped with automatic nutrient providers. After 12 days, the experiment was stopped and the cells were examined. The researchers found increased bone loss and an increase in genes involved in osteoclast maturation and activity among cells in the experimental group. Previous studies have found that astronauts can lose as much as 10 percent to 15 percent of preflight bone mass after only 6 months in space.

Identifying patients at high-risk of C. difficile infection
study published in Gastroenterology (April) validated a simple and reliable clinical prediction rule to identify high-risk patients most likely to benefit from measures to prevent recurrent Clostridium difficile infection (CDI). The rule includes the following variables: age (older than 65 years), severe or fulminant illness (by the Horn index), and additional antibiotic use after CDI therapy. In an independent cohort of 89 patients with CDI, the rule correctly identified groups of patients with increasing probability of recurrent C. difficile with 77.3 percent diagnostic accuracy.

Analgesics, mortality, and lumbar fusion
Analgesic-related deaths are the most common type of perioperative mortality among working patients who undergo lumbar fusion, according to a
study published in Spine (April 1). Researchers identified 2,378 lumbar fusion patients from workers’ compensation claims in Washington state between January 1994 and December 2001. By 2004, 103 of those patients were deceased. The 90-day perioperative mortality rate was 0.29 percent, while the 3-year cumulative mortality rate was 1.93 percent. The adjusted mortality rate for any cause was 3.1 deaths per 1,000 worker-years. Analgesic-related deaths were responsible for 21 percent of all deaths and 31.4 percent of all potential life lost. The risk of analgesic-related death was higher among workers who received instrumentation or intervertebral cage devices compared with recipients of bone-only fusions and among workers with degenerative disk disease.

A better treatment for osteoporosis?
study published in The Lancet (April 11) found that a single 5 mg intravenous infusion of zoledronic acid may be more effective in the prevention and treatment of glucocorticoid-induced osteoporosis than daily doses of 5 mg of oral risedronate. In a 1-year randomized, double-blind, double-dummy, noninferiority study in 54 centers across 16 countries including the United States, zoledronic acid was found to be noninferior and superior to risedronate for increase of lumbar spine bone mineral density in both the treatment and prevention subgroups at 12 months. Adverse events were more frequent in patients given zoledronic acid than in those on risedronate, largely due to transient symptoms during the first 3 days after infusion.

Keep stethoscopes, hands clean to prevent MRSA spread
In a prospective, observational cohort study, methicillin-resistant Staphylococcus aureus (MRSA) was found on approximately one in three stethoscopes in a single emergency department (ED). The authors swabbed 50 stethoscopes provided by consecutive, consenting emergency medical services (EMS) providers at a single academic ED. MRSA colonization was recorded as positive if three independent reviewers agreed on status. MRSA colonization was found on 16 of the 50 stethoscopes. Nearly one third of the EMS professionals had no recollection of when their stethoscopes had last been cleaned. The authors suggest that isopropyl alcohol wipes be made available at hospital emergency department entrances so EMS professionals can clean their stethoscopes regularly.

On a related note, a study presented at a meeting of the Society for General Microbiology in Britain found no evidence that isolation reduced MRSA transmission among patients in intensive care units. The authors suggested that compliance with hand hygiene practices may be more of a priority than moving MRSA patients to a single room or a separate MRSA bay.

Medicare rehospitalizations cost system billions
Rehospitalization among Medicare beneficiaries is prevalent and costly, according to data from a
study published in the New England Journal of Medicine (April 2). Analyzing Medicare claims from 2003–2004, researchers found that 19.6 percent of 11,855,702 Medicare beneficiaries discharged from hospitals were rehospitalized within 30 days, and 34.0 percent were rehospitalized within 90 days. Additionally, 67.1 percent of patients discharged with medical conditions and 51.5 percent of those discharged after surgical procedures were rehospitalized or died within the first year after discharge. The authors estimate that the cost to Medicare of unplanned rehospitalizations in 2004 was $17.4 billion.

Medical bloggers offer too much (or too little) public information
study recently published in the Journal of General Internal Medicine found that, of 271 blogs written by healthcare professionals across the United States (75 percent written by physicians), 42 percent described individual patients, and approximately 1 out of 6 contained enough information for patients to identify either their physicians or themselves. Furthermore, 1 in 10 promoted a specific product without including conflict-of-interest disclaimers.