AAOS Now

Published 1/1/2010

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.

High-impact exercise and OA
Data from a study presented at the annual meeting of the Radiological Society of North America (RSNA) find that, among middle-aged men and women who exercise frequently, high-impact activities may be damaging their knees and increasing their risk of osteoarthritis (OA). The authors analyzed data from 100 men and 136 women aged 45 to 55 who took part in the National Institutes of Health Osteoarthritis Initiative. Patients were grouped by degree of activity on the Physical Activity Scale for the Elderly (PASE), and the health of their right knees was assessed with magnetic resonance imaging. The incidence of abnormalities, grade of cartilage lesions, and presence of other knee abnormalities rose with increased PASE activity levels.

Percutaneous disk decompression versus conservative therapy
Data presented at the annual meeting of RSNA find that percutaneous disk decompression may help patients with herniated disks stay pain-free longer than those treated with standard therapy. In the randomized, controlled study of 17 men and 14 women (mean age: 36 years) with leg and back pain, patients received either percutaneous disk decompression or 6 weeks of rigorous conservative therapy (analgesics, anti-inflammatory drugs, and muscle relaxants). Patients in both groups reported reduced pain and increased mobility at 3-month follow-up, but at 12- and 24-month follow-up, surgical patients continued to improve, while patients treated conservatively reported a return of pain and decreased mobility.

Timing of surgery not significant in traumatic knee dislocations
A study in the Journal of Bone & Joint SurgeryAmerican (JBJS-A) (Dec. 1, 2009) finds that knee stability for patients who have surgery more than 3 weeks after a multiple ligament knee injury could potentially be comparable to that of patients who undergo more immediate surgery. A systematic review of 24 retrospective studies (396 knees) found that acute treatment (surgery less than 3 weeks after injury) was associated with residual anterior knee instability when compared with chronic treatment (surgery more than 3 weeks after injury) (p = 0.018), and that acutely managed patients were more likely to have more flexion deficits compared to chronically managed patients (p = 0.004). Early mobility was not associated with increased joint instability in acutely managed patients, and early mobility yielded fewer range-of-motion deficits without reducing the rate of follow-up manipulation or arthrolysis. Staged treatments (a combination of both repair and reconstruction in both the acute and chronic periods) yielded the highest percentage of excellent and good subjective outcomes.

DVT, PE risk greatest in first 12 weeks after surgery
A prospective cohort study of 947,454 middle-aged women in the United Kingdom from 1996 to 2001 finds that the risk of postoperative deep vein thrombosis (DVT) and pulmonary embolism (PE) is substantially increased in the first 12 weeks after surgery. Compared to women who had not had surgery, women who had an inpatient operation were 70 times more likely to be admitted with venous thromboembolism (VTE) in the first 6 weeks after surgery; women who had a day case (outpatient) surgery were 10 times more likely to be readmitted with VTE, compared to women who did not have surgery. By 7 to 12 weeks after surgery, the risks were lower but still increased. The pattern of risk was similar for both PE (n = 2,487) and DVT (n = 3,529). The postoperative risks of VTE varied by surgery type, with highest relative risks after inpatient surgery for hip or knee replacement and for cancer. The study appeared online in the British Medical Journal.

CA-MRSA strains increasing in hospitals
A study in Emerging Infectious Diseases (December 2009) finds that the community-associated (CA) strain of methicillin-resistant Staphylococcus aureus (MRSA) is becoming more common in hospitals. Based on data from more than 300 microbiology labs serving hospitals across the United States from 1999 to 2006, the percentage of MRSA infections increased by more than 90 percent, with a growth of around 10 percent each year among outpatients admitted to hospitals. The increase was caused almost entirely by CA-MRSA strains, which increased by more than 33 percent each year.

Dabigatran similar to warfarin for patients with acute VTE
A study in the New England Journal of Medicine (Dec. 10, 2009) finds that dabigatran has similar safety and efficacy to warfarin in the treatment of acute VTE. The randomized, double-blind, noninferiority trial of 2,539 patients randomly assigned to receive either 150 mg dabigatran twice daily or warfarin, dose-adjusted to achieve an international normalized ratio of 2.0 to 3.0, found that 2.4 percent of patients in the dabigatran group had recurrent VTE, compared to 2.1 percent in the warfarin group (p < 0.001 for the prespecified noninferiority margin). Major bleeding episodes occurred in 20 patients assigned to dabigatran (1.6 percent) and in 24 patients assigned to warfarin (1.9 percent), and episodes of any bleeding were observed in 205 patients assigned to dabigatran (16.1 percent) and 277 patients assigned to warfarin (21.9 percent).