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AAOS Now

Published 1/1/2012

Second Look—Clinical News and Views

Treating frozen shoulder
A study published online in Clinical Orthopaedics and Related Research (CORR) examines the natural history of spontaneous idiopathic frozen shoulder and finds that many patients recover normal levels of function without treatment. The retrospective review of 103 patients treated for frozen shoulder (84 shoulders; 56 women) at 2 to 27 years (mean = 9 years) after initial consultation found that, for the 51 patients (52 shoulders) who were treated only with observation or benign neglect, the disease lasted an average of 15 months and at last follow-up, range of motion had returned to the contralateral level in 94 percent of patients. Nineteen of 20 patients who underwent manipulation under anesthesia also had a return to contralateral range of motion.

Crosslinked polyethylene liners and wear
According to a study presented at the annual meeting of the American Association of Hip and Knee Surgeons (AAHKS), crosslinked liners demonstrate reduced wear and osteolysis compared to conventional liners for total hip arthroplasty (THA). The prospective, randomized study involved 230 THA patients who received either conventional non-crosslinked polyethylene liners (n = 114) or crosslinked liners. At 10-year follow-up, survivorship was 94.6 percent (+/- 4.6 percent) in the non-crosslinked group and 100 percent in the crosslinked group. The mean liner wear was 0.21 mm/year (non-crosslinked) and 0.03 mm/year (crosslinked), and the incidence of osteolysis (at least 1.5 square centimeters) was 25 percent (non-crosslinked) and 0 percent (crosslinked).

Cost effectiveness of spine surgery
According to a study in Spine (Nov. 15, 2011), spine surgery offers persistent improvements in quality-adjusted life years (QALYs) through 4-year follow-up for three common diagnoses. Based on data from the Spine Patient Outcomes Research Trial for patients diagnosed with degenerative spondylolisthesis, spinal stenosis, or intervertebral disk herniation, researchers found that surgery improved health, with costs per QALY decreasing for all three procedures over the course of the study.

Cryotherapy after knee arthroscopy
A study in the Journal of Bone & Joint Surgery—American (Nov. 2, 2011) finds that the concentration of synovial prostaglandin E2 (PGE2)—a marker of pain and inflammation—can be decreased after knee arthroscopy through local cryotherapy and compression. The prospective, randomized study of 40 knee arthroscopy patients, 20 of whom received postoperative cooling and compression, found that application of the cooling and compression device significantly lowered the temperature in the operatively treated knee (measured on the skin, within the joint capsule, and intra-articularly). The cooling and compression also appeared to decrease inflammation but not postoperative pain, and appeared to have a positive anti-inflammatory effect.

Fracture-specific stems for hemiarthroplasty
According to a study in CORR (December 2011), the use of fracture-specific stems during proximal humeral hemiarthroplasty may improve function and healing compared to conventional stems. The retrospective review of 170 patients treated for proximal humeral fracture between September 2001 and March 2004 found that patients treated with fracture-specific prostheses had improved outcomes compared to patients with conventional prostheses in the following areas: active anterior elevation, active external rotation, and American Shoulder and Elbow Surgeons score.

Common medications and ADEs
A study in the New England Journal of Medicine (Nov. 24, 2011) finds that most emergency hospitalizations necessitated by adverse drug events (ADEs) in older adults result from a few commonly used medications, including blood thinners. Based on data from the National Electronic Injury Surveillance System–Cooperative Adverse Drug Event Surveillance project, researchers found that 65.7 percent of emergency hospitalizations among adults age 65 or older were due to unintentional overdoses. Four medications or medication classes were implicated alone or in combination in two thirds of hospitalizations: warfarin (33.3 percent), insulins (13.9 percent), oral antiplatelet agents (13.3 percent), and oral hypoglycemic agents (10.7 percent).

No advantage to newer bearing surfaces
Results from a study published online in the British Medical Journal (BMJ) suggest that metal-on-metal (MoM) hip implants offer little advantage compared to metal-on-polyethylene (MoP) designs. The retrospective review of data from 18 comparative studies (3,139 patients, 3,404 hips) and more than 830,000 procedures listed in national registries found either no difference or a slight advantage for patients who received MoP implants in disease-specific functional outcomes and general quality of life scores. The three largest national registries displayed higher rates of implant revision associated with MoM implants compared with MoP implants.

Growth hormone and bone formation
According to a paper presented at the annual meeting of the Radiological Society of North America, administration of growth hormone (GH) can increase bone formation and bone marrow fat in abdominally obese women. The 6-month, randomized, double-blind, placebo-controlled trial involved 79 premenopausal women with abdominal adiposity. At baseline, 32 percent of patients were osteopenic and one patient had osteoporosis. At 6 months, patients who received GH displayed increased bone formation, increased bone marrow fat and muscle mass, higher levels of Vitamin D, and a reduction in abdominal fat compared to the placebo group.

Vertebroplasty issue a microcosm of difficulties surrounding CER
The December issue of Health Affairs examines the issue of percutaneous vertebroplasty in relation to comparative effectiveness research (CER). Insurers continue to cover vertebroplasty, despite the August 2009 publication of data from two rigorous double-blind, randomized, controlled trials that found the procedure provided no better pain relief than a sham procedure in which needles were introduced into the back without injecting cement. Vertebroplasty was approved for insurance coverage despite the fact that no data were available at the time from randomized clinical trials.

Risk factors for in-hospital falls
A study published online in the Journal of Arthroplasty found that the following are independent risk factors for in-hospital falls (IFs): revision surgery, advanced age, male sex, minority race, and the presence of comorbidities. Data were based on the Nationwide Implant Sample (1998–2007). Patients having an IF tended to have longer hospital stays and were less likely to be discharged to their primary residence. In-hospital mortality, complications, and cost were higher in patients sustaining IF.

Bisphosphonates and implant survival
A study published online in BMJ finds that bisphosphonate use is associated with a significant increase in implant survival for patients undergoing lower extremity arthroplasty. The population-based retrospective cohort study of 41,995 patients who underwent primary hip or knee arthroplasty found that bisphosphonate users (n = 1,912) had a lower rate of revision at 5 years, compared to non-users. In addition, bisphosphonate users had a 1.96-fold increase in time to revision than non-users.

These items originally appeared in AAOS Headline News Now, a thrice-weekly enewsletter that keeps AAOS members up to date on clinical, socioeconomic, and political issues, with links to more detailed information. Subscribe at www.aaos.org/news/news.asp (member login required)