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ScienceDaily (Nov. 20, 2009) — Researchers have shown how an experimental drug might restore the function of nerves damaged in spinal cord injuries by preventing short circuits caused when tiny “potassium channels” in the fibers are exposed. More »

ScienceDaily (June 30, 2009) — A new study indicates that bone-morphogenetic protein (BMP; a biological agent used to promote bone creation) is used in 25 percent of spinal fusion procedures and is associated with a higher rate of complications than in fusions that did not use BMP, and greater hospital charges for all categories of spinal fusions, according to a report in the July 1 issue of the Journal of the American Medical Association (JAMA).

Back pain continues to be a leading cause of disability in the United States and is one of the most common reasons for seeking evaluation by a physician, second only to the common cold. “Nonsurgical interventions remain the first-line of therapy; however, many patients eventually progress to surgical treatments with 1 option including fusion. Spinal arthrodesis (fusion) as a treatment for back pain has rapidly evolved with the development of advanced spinal instrumentation and biologics to promote bony fusion,” the authors write.

According to background information in the article, BMPs promote bone creation and remodeling and clinical use of recombinant BMP protein was approved by the U.S. Food and Drug Administration (FDA) in 2002 for surgery of the anterior lumbar spine to promote bone fusion. The current rates and patterns of BMP use since the clinical introduction more than 5 years ago are not known at the national level and no population-based data are available. Likewise, the complication rates and financial impact associated with national BMP usage have not been evaluated.

Kevin S. Cahill, M.D., Ph.D., M.P.H., of Brigham and Women’s Hospital, Boston, and colleagues examined the national trends in the adaptation of BMP into clinical practice since 2002 and the association between BMP use and postoperative complications, length of stay and hospital charges. The analysis included data on 328,468 patients who underwent spinal fusion procedures from 2002-2006, identified from the Nationwide Inpatient Sample database, a 20 percent sample of U.S. community hospitals.

The researchers found that when comparing immediate postoperative, in-hospital rates of complications for the year 2006 among patients undergoing spinal fusion by BMP use status, no differences were seen for lumbar, thoracic, or posterior cervical procedures. After additional analysis, the use of BMP in anterior cervical fusion procedures was associated with a higher rate of complication occurrence (7.09 percent with BMP vs. 4.68 percent without BMP) with the primary increases seen in wound-related complications (1.22 percent with BMP vs. 0.65 percent without BMP) and dysphagia (difficulty in swallowing) or hoarseness (4.35 percent with BMP vs. 2.45 percent without BMP). BMP use was associated with greater inpatient hospital charges across all categories of fusion. Increases between 11 percent and 41 percent of total hospital charges were reported, with the greatest percentage increase seen for anterior cervical fusion.

Results from the study also indicated that nationwide usage of BMP has increased from 0.69 percent of all fusions in 2002 to 24.89 percent of all fusions in 2006. Use of BMP varied by patient sex, race, and primary payer with increased use seen in women, Medicare patients and decreased use in nonwhite patients.

“In conclusion, this report highlights the robust nationwide application of BMP in spinal fusion procedures in the first 5 years of clinical usage since FDA approval. The effects on complication occurrence in anterior cervical fusion, as well as the increases in length of stay and hospital charges illustrate the need to continue to develop refined guidelines for usage and to further study the long-term risks and benefits of usage,” the authors conclude.

1. Kevin S. Cahill; John H. Chi; Arthur Day; Elizabeth B. Claus. Prevalence, Complications, and Hospital Charges Associated With Use of Bone-Morphogenetic Proteins in Spinal Fusion Procedures. JAMA, 2009; 302 (1): 58-66 [link]

BY LAUREN UZDIENSKI, JUNE 29, 2009

We reported back in April that teriparatide, a recombinant form of parathyroid hormone marketed by Eli Lilly as Forteo, may help bones to heal following a fracture. Now a new study published in JBJS reports on an additional application for teriparatide: preventing new vertebral fractures in osteoporotic patients.

The analysis was conducted from previously-published data from about 1,200 patients in the Fracture Prevention Trial. These patients were able to walk, had undergone menopause at least five years previously and had at least one moderate or two mild atraumatic vertebral fractures at baseline.

At approximately two years, teriparatide was shown to “significantly reduce” the occurrence of new vertebral fractures in the study population. New, new adjacent and new nonadjacent vertebral fractures were reduced by 72%, 75% and 70%, respectively, when compared to placebo.

Raloxifene, a selective estrogen receptor modulator used to prevent osteoporosis, was found to have similar benefits. New, new adjacent and new nonadjacent vertebral fractures were reduced by 54%, 54% and 53%, respectively, when compared to placebo. The raloxifene data was pulled from about 2,500 patients in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial. Raloxifene is marketed as Evista by Eli Lilly, who also provided funding for the study.

ScienceDaily (June 15, 2009) — In many sensory neuronopathies, painful conditions affecting sensory nerves outside the brain and spinal cord, the affected nerves are in a region known as the DRG. These conditions are difficult to treat. However, researchers have now developed an approach to target therapeutic genes to DRG nerves, and used it to reduce sensory nerve dysfunction in a mouse model of Sandhoff disease, an inherited condition in which many nerves, including those in the DRG, are affected.

Medical conditions that affect sensory nerves outside the brain and spinal cord are known as sensory neuronopathies. These conditions, which are extremely painful, include shingles and can be caused by anticancer drugs such as cisplatin. In many sensory neuronopathies, the nerves that are dysfunctional are those in a region of the body known as the dorsal root ganglion (DRG), and these conditions are particularly difficult to treat. However, Lawrence Chan and colleagues, at Baylor College of Medicine, Houston, have developed an approach to target therapeutic genes to nerves in the DRG, and used it to reduce sensory nerve dysfunction in a mouse model of Sandhoff disease, an inherited condition in which many nerves, including those in the DRG, are affected.

The authors developed a system to generate helper-dependent adenoviruses that targeted only DRG nerves. These were used to deliver genes to DRG nerves in mice and found to be dramatically more efficient at gene delivery than nontargeted helper-dependent adenoviruses. In mice lacking the Hexb gene, which are consider a mouse model of Sandhoff disease, administration of DRG-targeted helper-dependent adenoviruses carrying the Hexb gene restored Hexb expression in DRG nerves and eliminated sensory nerve dysfunction. The authors hope this approach could be developed for treating different forms of DRG sensory neuronopathies.

1. Terashima et al. DRG-targeted helper-dependent adenoviruses mediate selective gene delivery for therapeutic rescue of sensory neuronopathies in mice. Journal of Clinical Investigation, 2009; DOI: 10.1172/JCI39038