AAOS Now

Published 7/1/2010

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.

Treating tarsal navicular stress fractures
Non–weight-bearing conservative management should be considered the standard of care for tarsal navicular stress fractures, according to a systematic literature review published in the American Journal of Sports Medicine (May). The authors used a mixed generalized linear model with study as a random effect and treatment as a fixed effect, and compared cases based on type of treatment: conservative, weight bearing permitted; conservative, non–weight bearing (NWB); and surgical. No statistically significant difference in outcomes was found between NWB conservative treatment and surgical treatment, but a statistical trend favored NWB management over surgery. Weight bearing as a conservative treatment was shown to be significantly less effective than either NWB or surgical treatment.

Causes of local anesthetic chondrotoxicity
A study in the American Journal of Sports Medicine (June) finds that the chondrotoxicity of local anesthetics containing epinephrine may be due to a combined effect of low pH and the preservative sodium metabisulfite. The authors harvested human chondrocytes and cultured 10 batches, using a custom bioreactor designed to simulate metabolism of medication. After 24 hours of perfusion, viability assays were performed. Cultures with media titrated to pH 4.5, pH 5.0, and local anesthetics containing epinephrine (pH 4.0–5.5) had high cell death rates compared with controls at all time points; cultures containing 1:100000 and 1:200000 epinephrine alone had no increased death rate. Also, 0.5 mg/mL sodium metabisulfite preservative had a significant effect on cell death, yet the preservative methylparaben had no effect. The percentage of cell death was not significant for 1 percent lidocaine and 0.25 percent bupivacaine.

Treating distal radial fractures in older patients
A study in the Journal of Hand Surgery (May) finds efficacy in both closed reduction plaster cast fixation (CRPCF) and external fixation (EF) for the treatment of distal radial fractures in older patients. A retrospective review of 46 consecutive patients 65 years and older with distal radial fractures and treated with either CRPCF or EF found that the average wrist extension and ulnar deviation (clinically) and palmar tilt and radial height (radiologically) were statistically better in the EF group, but no statistically significant difference was found in DASH scores; wrist flexion, radial deviation, pronation, supination, grip strength, or pinch strength (clinically); or ulnar variance or radial inclination (radiologically). Patients in the CRPCF group were more likely to experience posttreatment complications although the difference was not statistically significant.

Body checking triples youth hockey injury rate
Data from a study of ice hockey players in Canadian youth leagues show that the risk of injury to players triples when the league allows body checking. A prospective cohort study of 74 teams from Alberta, where body checking is permitted, and 76 teams from Quebec, where body checking is not permitted, found 241 injuries reported in Alberta and 91 injuries reported in Quebec. For game-related injuries (Alberta, 209; Quebec, 70), the Alberta/Quebec incidence rate ratio was 3.26; for all injuries, it was 3.88, and for severe injury (time loss, >7 days), it was 3.61. The study was in the Journal of the American Medical Association (June 9).

Bisphosphonates and femur fractures
A study in the New England Journal of Medicine (May 13) finds no significant increase in risk of femoral shaft fractures associated with the use of bisphosphonates, although the authors point out that no definitive conclusions should be drawn. Secondary analyses of 284 records of women participating in three large, randomized bisphosphonate trials and a review of fracture records and radiographs (when available) from all hip and femur fractures were used to assess atypical fractures as well as to identify those below the lesser trochanter and above the distal metaphyseal flare (subtrochanteric and diaphyseal femur fractures). Twelve fractures in 10 patients occurred in the subtrochanteric or diaphyseal femur—a combined rate of 2.3 per 10,000 patient-years. Compared with placebo, the relative hazard was 1.03 for alendronate use in one trial, 1.50 for zoledronic acid use in a second trial, and 1.33 for continued alendronate use in the third trial. Although increases in risk were not significant, confidence intervals were wide.

Psychological factors predict chronic pain
According to a report by Australian researchers in The Journal of Pain (May), psychological factors, such as pessimism about recovery and depression, are major predictors of chronic pain in trauma patients recovering from non–life-threatening orthopaedic injuries. Researchers evaluated 168 patients with a range of non–life-threatening orthopaedic injuries, including many injuries that were sustained at work. They found a high prevalence of pain 6 months following injury and also found that psychological and mood factors were significant contributors to increased risk of chronic pain. Identifying these factors may help to assess functional outcomes in orthopaedic injury patients returning to work.

Heat, cold have similar effect on back pain
An online study from Academic Emergency Medicine (April 23)finds little evidence that topical application of heat or cold in addition to ibuprofen therapy for treatment of acute neck or back strain is directly related to reduction in pain severity. In a randomized, controlled trial, 60 patients were treated with 400 mg ibuprofen and 30 minutes of either heat (n=31) or cold therapy. Both groups were similar in baseline patient and pain characteristics and, based on a visual analog scale of 0 mm (no pain) to 100 mm (worst pain), the groups had similar responses. Pain was rated better or much better in 16 of the 31 patients treated with heat and in 18 of the 29 patients treated with cold, but it is possible that the pain relief was mainly the result of the ibuprofen therapy.

No link between vitamin A and fracture risk
According to data published in Archives of Dermatology (May), exposure to systemic vitamin A analogues is not associated with increased risk of fracture. A review of 124,655 patients with fractures and 373,962 age- and sex-matched controls from a nationwide data-base found no trend showing increased risk of hip, forearm, or spine fracture associated with increased doses or durations of treatment with vitamin A analogues, after control for social variables, contacts with hospitals and general practitioners, alcoholism, and other variables known to potentially affect fracture risk.

C. difficile can be transmitted through air
A study in Clinical Infectious Diseases (June) finds that Clostridium difficile can be spread through the air as well as through direct contact with contaminated surfaces. Measuring airborne and environmental C. difficile adjacent to 63 patients with symptomatic C. difficile infection (CDI) showed that 12 percent of the first 50 patients examined had positive air samples. Intensive sampling around 10 patients with CDI symptoms (10 hours each over 2 days), as well as a total of 346 surface sites, found that 60 percent of patients had both air and surface environments positive for C. difficile. Molecular characterization confirmed an epidemiologic link between airborne dispersal, environmental contamination, and CDI cases.

Diagnosing Madelung’s deformity
A study in the Journal of Hand Surgery (May) established the diagnostic threshold of four radiographic measurements for Madelung’s deformity. Reviewers unanimously agreed on a diagnosis of Madelung’s deformity when any one of the following conditions were met: ulnar tilt of 33º or greater, lunate subsidence of 4 mm or more, lunate fossa angle of 40º or greater, or palmar carpal displacement of 20 mm or more.