AAOS Now

Published 3/1/2010

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.

Planning acetabular labral repairs
A review of 100 consecutive patients who received both a conventional 3-tesla magnetic resonance imaging (MRI) scan and a magnetic resonance (MRA) arthrogram finds that MRI can be sufficient for preoperative planning for acetabular labral repair. MRA detected acetabular labral tears in 72 of the 100 patients, while MRI discovered acetabular labral tears in 71 of the 100 patients. Conventional MRI recorded sensitivity of 97 percent and specificity of 100 percent for acetabular labral tears compared to arthroscopy; MRA scored 100 percent in both sensitivity and specificity.

New method for tracking MRSA
Researchers have developed a new method to track how methicillin-resistant Staphylococcus aureus (MRSA) is transmitted. A new genomics approach can compare individual MRSA isolates to precisely show genetic relatedness. The method is able to spot single-letter changes in the genetic code and to identify differences between even the most closely related of MRSA isolates. By identifying single letter changes in the individual genomes and making calculations based on the dates at which the samples were taken, the team was able to derive a mutation rate and develop an evolutionary tree of MRSA. European isolates were concentrated around the base of the evolutionary tree. The study was published in the Jan. 22 issue of the journal Science (Jan. 22, 2010).

Natural grass and cleats reduce ACL injuries
According to a study published in the Journal of Biomechanical Engineering (January), athletes place less strain on their anterior cruciate ligaments (ACLs) while making a cutting maneuver if they are on a natural grass surface and wearing cleats. Eight cadaveric lower extremities were tested in a custom apparatus that allowed axial loading and tibial rotation but prevented femoral rotation. Four different surface/shoe combinations were tested: AstroTurf/turf shoes, modern playing turf/turf shoes, modern playing turf/cleats, and natural grass/cleats. In experimental trials, the natural grass/cleats combination resulted in significantly less maximum strain (p < 0.05) than any of the other combinations.

Musculoskeletal conditions common reason for evacuation
A study published in The Lancet (Jan. 23) finds that musculoskeletal and connective tissue disorders were the most common reasons for medical evacuation for U.S. military personnel removed from Iraq and Afghanistan between January 2004 and December 2007. Based on 34,006 military personnel records, 24 percent (n = 8,104) were evacuated for musculoskeletal and connective tissue disorders. Other common reasons for evacuation included combat injuries, neurologic disorders, psychiatric diagnoses, and spinal pain.

Withholding anticoagulation treatment
A retrospective review published in the Journal of the American Medical Association (Feb. 3) finds that withholding anticoagulation treatment after a single whole-leg compression ultrasound (CUS) with a negative result may be associated with a low risk of venous thromboembolism (VTE). Based on results from seven studies with 4,731 patients who did not receive anticoagulation treatment after a negative whole-leg CUS examination, VTE or suspected VTE-related death occurred in 34 patients (0.7 percent), including 11 with distal deep vein thrombosis (DVT); 7 with proximal DVT; 7 with nonfatal pulmonary emboli; and 9 whose deaths were possibly VTE-related. The combined VTE event rate at 3 months was 0.57 percent.

Biomarkers for RA patients
Plasma type I interferon activity, the ratio of interferon-beta to interferon-alpha, and interleukin-1 receptor antagonist (IL-1Ra) level were all predictive of therapeutic response in tumor necrosis factor (TNF) antagonist-treated rheumatoid arthritis (RA) patients, according to data published in Arthritis & Rheumatism (February). The authors examined 35 RA patients treated with TNF antagonist therapy; 12 RA patients not treated with a TNF antagonist served as controls. Plasma type I interferon activity at baseline was significantly associated with clinical response, with higher activity associated with a good response. Changes in Disease Activity Score in 28 joints were greater among patients with a baseline plasma ratio of interferon beta to interferon alpha of greater than 0.8. Elevated baseline IL-1Ra levels were also associated with better therapeutic outcomes.

Denosumab as a possible GCT treatment
According to a study published online in The Lancet Oncology, denosumab may be effective in treating patients with giant-cell tumor (GCT) of bone, and further investigation is warranted. An open-label, single group study of 37 patients with recurrent or unresectable GCT found that patients treated with subcutaneous denosumab (120 mg every 28 days, with loading doses on days 8 and 15 of month 1) 30 had a tumor response at 25 weeks, defined as elimination of at least 90 percent of giant cells or no radiologic progression of the target lesion. Overall, 33 of 37 patients reported adverse events; of 5 serious adverse events, none was deemed treatment-related.

No “weekend effect” among trauma patients
A study presented at the annual scientific assembly of the Eastern Association for the Surgery of Trauma suggests that trauma patients may be insulated from the so-called weekend effect, which suggests that patients treated for cardiac or neurologic emergencies overnight and on weekends are more likely to experience negative outcomes than those who come to the hospital on weekdays. A retrospective cohort study of 4,382 patients at a single level 1 trauma center from 2006 to 2008 found that trauma patients who were seen on weekends were not more likely to die than those who were seen on weekdays (5.2 percent vs. 5.3 percent). Trauma patients who were seen at night were also not more likely to die than those who were seen during the day (4.4 percent vs. 5.5 percent).

Fracture risk doubles with opioid use
A study published online in the Journal of General Internal Medicine finds that opioid doses of greater than 50 mg/day may be linked to an increase in fracture risk. Researchers reviewed the records of 2,341 integrated healthcare plan members aged 60 years and older who received three or more opioid prescriptions within a 90-day period for chronic, noncancer pain between 2000 and 2005. Opioid use was associated with a trend toward increased fracture risk compared with patients not taking opioids. Higher dose opioid use (≥ 50 mg/day) was associated with a 9.95 percent annual fracture rate and a twofold increase in fracture risk. Of the fractures in the study cohort, 34 percent were of the hip or pelvis, and 37 percent were associated with inpatient care.

NPWT international consensus recommendations
An international meeting on negative pressure wound therapy (NPWT) has released its “Global Consensus on NPWT.” The recommendations include the following:

  • Acute wounds—orthopaedic trauma: NPWT may be used when primary closure is not possible after or between débridements as a bridge to definitive closure.
  • Chronic wounds—venous leg ulcers: If compression is not efficacious, the wound must be reassessed, débrided, and then NPWT may be used to prepare the wound for surgical closure.
  • Surgical wounds—burns: NPWT may be beneficial at preventing wound progression.