AAOS Now

Published 6/1/2009

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.

Hormones and knee laxity
Research
published in the British Journal of Sports Medicine (March 2009) and the American Journal of Sports Medicine (March 2009) finds that changes in knee joint laxity (KJL) may be associated with hormonal changes during a woman’s menstrual cycle. Not all women, however, experience the KJL changes at the same time during their cycles.

‘Nonsurgical’ treatment for chronic Achilles tendinosis
In a
paper presented at the 2009 annual meeting of the American Roentgen Ray Society, researchers from the Northwestern University Feinberg School of Medicine reported on ultrasound-guided Achilles tendon débridement to treat chronic Achilles tendinosis that does not respond to conservative care. Of 17 patients treated with the procedure, approximately 60 percent reported that their symptoms had either completely resolved or were markedly improved.

Bone loss common among prostate cancer patients
According to
data presented at the annual meeting of the American Urological Association, patients with advanced cases of prostate cancer who are being treated with androgen deprivation therapy (ADT) are at risk for bone fractures or critical bone loss. Researchers conducted a 2-year, double-blind, placebo-controlled, randomized study of 1,389 ADT patients at approximately 150 clinical sites in the United States and Mexico. The phase III clinical trial evaluated the effectiveness of the selective estrogen receptive modulator toremifene (80 mg) in preventing bone fractures. Nearly one in four patients (23.9 percent) receiving a placebo sustained a nontraumatic fracture (morphometric vertebral fracture or clinical fragility fracture) or experienced critical bone loss (greater than 7 percent) within 2 years.

Cementless acetabular component 20-year results
A
study published in the Journal of Bone & Joint Surgery—American (JBJS-A) (May 2009) finds that cementless acetabular reconstruction may continue to provide long-term durable fixation. The research team evaluated 114 hips with minimum 20-year follow-up. The 20-year rate of survival of the metal shell, with failure defined as revision because of loosening or radiographic evidence of loosening, was 96 percent (95 percent confidence interval, 94 percent to 98 percent). Wear-related complications were found to be the major mode of failure.

Disability on the rise; arthritis most common cause
According to the U.S. Centers for Disease Control and Prevention, nearly 48 million people in the United States have a disability, and arthritis is the most common cause (19.0 percent). Other causes of disability include back or spine problems (16.8 percent), stiffness or deformity of limbs/extremities (3.6 percent), and broken bone/fracture (2.1 percent). The
data was drawn from the Survey of Income and Program Participation—a longitudinal panel survey conducted by the U.S. Census Bureau.

Obesity, arthritis and older women
Obesity and arthritis that take root during early and middle age significantly contribute to decreased quality of life as women age, according to
research presented at the annual scientific meeting of the American Geriatrics Society. The researchers reviewed data from 5,888 people older than 65 years taking part in the Cardiovascular Health Study. Women sustained more than twice as many disabilities than men of the same age and were more likely than men to experience fractures, vision problems, and bronchitis. Men were more likely to have emphysema, coronary heart disease, congestive heart failure, stroke, diabetes, and hearing problems.

HO likely in high-energy trauma injuries
Military personnel who are wounded in combat as the result of a high-energy trauma are at increased risk of heterotopic ossification (HO), according to the results of a
study published in JBJS-A (May 2009). Based on data from 243 patients who met inclusion criteria and were treated for orthopaedic injuries at the National Naval Medical Center in Bethesda, Md., between March 1, 2003, and Dec. 31, 2006, researchers found an observed rate of heterotopic ossification of 64.6 percent. A significant relationship between heterotopic ossification and the presence (P=0.006) and severity (P=0.003) of a traumatic brain injury was noted. Risk factors for the development of HO included age younger than 30 years, an amputation, multiple extremity injuries, and an Injury Severity Score of 16.

Risk of rotator cuff tears hereditary?
According to
data published in JBJS-A (May 2009), people with relatives who have experienced rotator cuff tears may be at increased risk of similar tendon tears. Based on data from 652 patients diagnosed with cuff tears before the age of 40 years, researchers found significant excess relatedness for individuals with rotator cuff disease in close and distant relationships (up to third cousins) (P=0.001). The relative risk of rotator cuff disease in the relatives of patients diagnosed before the age of 40 years was significantly elevated for second-degree (relative risk=3.66, P=0.0076) and third-degree (relative risk=1.81, P=0.0479) relatives.

Weak hips linked to leg injuries in runners
Weak hip-stabilizing muscles may lead to atypical lower extremity mechanics and increased forces within the lower extremity while running, according to a
study published in Sports Health (May/June 2009). According to the authors, most risk factors researched in recent years can be generally categorized into 2 groups: atypical foot pronation mechanics and inadequate hip muscle stabilization. They found no definitive link between atypical foot mechanics and running injury mechanisms, although they state that progress has been hampered by a lack of normative data. Weak hip muscles can destabilize the leg and increase the risk of injury.

Lower extremity injuries more common in obese children
According to
data presented at the annual meeting of the Pediatric Academic Societies, obese children are significantly more likely than non-obese children to incur lower body injuries. The researchers examined the records of 23,349 children who sustained a traumatic injury (ICD-9 codes 800-899) and visited a single emergency department between Jan. 1, 2005, and March 31, 2008. About 16 percent of patients were classified as obese. Overall, obese and non-obese children had the same percentage of upper extremity injuries. Obese children had significantly fewer head and face injuries than non-obese children (P<0.001), but were significantly more likely to have lower extremity injuries compared to upper extremity injuries than non-obese children (>P<0.001).>

Dairy calcium better than calcium carbonate
A study published online in the Journal of Bone and Mineral Research (May 2009) finds that calcium derived from dairy products may promote bone growth and strength more effectively than calcium derived from supplements such as calcium carbonate. Femurs from rats fed nonfat dry milk solids (NFDM) had 8.4 percent higher peak breaking force, 6.4 percent greater calcium content, 4.8 percent greater weight, 4 percent greater width, 1.2 percent greater density, 13.1 percent greater midshaft cortical thickness, and 16.7 percent greater midshaft cortical area than femurs from rats fed calcium carbonate.

Radiographs can help detect early jawbone damage
An
article in General Dentistry (March/April 2009) states that radiographs can detect so-called “ghost sockets,” which occur when the jawbone is not healing properly and are associated with early stages of osteonecrosis, which has been linked to use of bisphosphonates.

Scaffold designed to mimic articular joint tissues
A new family of osteochondral scaffolds based on collagen-glycosaminoglycan (collagen-GAG) and calcium phosphate technologies is discussed in a series of articles published online in the Journal of Biomedical Materials Research Part A. The scaffolds consist of two layers: a mineralized type I collagen-GAG scaffold designed to regenerate the underlying subchondral bone and a nonmineralized type II collagen-GAG scaffold designed to regenerate cartilage. Researchers claim that the design mimics the composition of two main tissue types found in articular joints, with particular emphasis on the osseous compartment of an osteochondral scaffold.

I: Control of chemical composition

II: Fabrication of a mineralized collagen-glycosaminoglycan scaffold

III: Fabrication of layered scaffolds with continuous interfaces