The North American Spine Society (NASS), the worlds leading multidisciplinary spine society, kicked off its 21st annual meeting Wednesday in Seattle. NASS will host more than 3,000 spine care experts from around the globe during the five-day meeting held September 26-30 at the Sheraton Seattle Hotel and Towers. At the meeting, NASS members will hear about cutting-edge research in more than 300 scientific presentations, attend 8 symposia, and view the most advanced technology in the industry from more than 190 exhibitors. Following are highlights of new research being presented this week:

Total Hip Replacement Relieves Low Back Pain
Total hip replacement is one of the most successful operations in medicine, and it may have an unanticipated benefit. According to a small study from American and Israeli spine centers, the procedure can also relieve low back pain and improve spinal functional limitations. Peleg Ben-Galim, MD, and colleagues prospectively studied changes in hip and spine symptoms and disability in 25 men and women (mean age 67 years). In addition to expected improvements in hip pain and function, they noted significant decreases in low back pain and Oswestry disability scores. The study is among the first to demonstrate the clinical benefits total hip replacement has upon back pain, suggested Ben-Galim, of Baylor College of Medicine in Houston. For patients with problems in both anatomic areas, the findings may help answer the common question, What should I treat firstthe hip or the spine?

Fresh Evidence for Patients Interested in Total Disc Replacement
Lumbar total disc replacement with the ProDisc artificial disc is superior to circumferential (360-degree) fusion in patients with single-level degenerative disc disease, according to a pivotal FDA-regulated trial sponsored by device maker Synthes. NASS member Rick B. Delamarter, MD, and colleagues randomized 242 patients (mean age ~40 years) with back and/or leg pain to the ProDisc (162 patients) or fusion (80 patients), then followed them for two years. According to outcome criteria developed by Synthes, the overall success rate was 64% in the ProDisc group and 45% in the fusion group. By stricter FDA standards, success rates were less impressive--53% in the ProDisc group and 41% in the fusion group. The FDA analysis suggests ProDisc leads to greater patient satisfaction and overall success than fusion, but similar improvements in disability and pain.


Sacroplasty Safe and Effective for Sacral Osteoporotic Fractures
Sacroplasty, a procedure in which an injected cement stabilizes a sacral insufficiency fracture, virtually eliminates low back pain in patients with bone weakened by osteoporosis, according to a one-year, multi-center cohort study by NASS member Michael Frey, MD, and colleagues. The injection is safe and pain reduction is both swift and sustained, they add. Among the 25 patients enrolled in the uncontrolled study, the mean pain score on a 10-point visual analog scale was 7.3 at baseline, 2.7 immediately post-procedure, and 0.3 at one year. Symptoms often take 9 to 12 months to abate if the fracture is left untreated.

Cervical Spine Degeneration No Impediment to Healthy Elders

Some very elderly (over age 80) men and women who have degenerative cervical spines suffer in pain while others report no symptoms or functional impairment, according to Shunji Matsunaga, MD, PhD, and colleagues from Kagoshima University in Japan. Scientists hope eventually to determine what causes some degeneration to be painful and some to be painless. The authors compared radiographic findings in 52 elderly patients who reported neurological symptoms to findings in 50 super healthy elders who had no neck pain and who led independent, healthy lives. There were no differences between groups in disc degeneration and spur formation, though the spinal canal diameter was significantly greater among healthy elders. Healthy elders also had performed significantly more exercise during their lifetimes. Radiographic evidence of degeneration is common in healthy elderly with no symptoms and is not an indication for intervention, conclude Matsunaga et al.


Spine MRI Abnormalities Rarely Cause Serious Low Back Pain
Patients with a new episode of vexing back pain should not expect MR imaging to provide a diagnostic explanation. Development of serious low back pain is rarely marked by corresponding new and relevant structural changes, according to a prospective study by NASS member Eugene Carragee, MD, and colleagues at Stanford University and the University of Hawaii. The authors took MR images of 200 patients who had a lifetime history of no significant back problems but risk factors for future low back pain, and followed them for five years. Only two of 51 patients (4%) who developed serious low back pain had clinically significant MRI changes, suggesting that the cause of the pain is rarely structural. Common degenerative findings are often interpreted as recent developments and the probable anatomic cause of new symptoms, according to Carragee et al. Instead, suggests the new data, Findings on MR imaging within 12 weeks of serious low back pain inception are highly unlikely to represent new structural changes.


Opioid Dependence Linked to Worse Outcomes After Back Injury
Recent years have seen a sharp rise in the use of opioid therapy to treat back pain. Although opioids may help some patients, chronic use after a disabling injury has steep socioeconomic costs, according to new research. NASS member Tom Mayer, MD, and colleagues from PRIDE in Dallas studied 1,200 patients who successfully completed an intensive functional rehabilitation program that included detoxification. Opioid dependence one year later nearly doubled the risk that a patient would be out of work. It also doubled the likelihood that a patient had engaged in excessive healthcare-seeking behavior, or doctor shopping, apparently to find a physician willing to provide opioids. Physicians who treat patients with work-related back pain must be cautious in prescribing chronic opioid medication, and be alert to the de-motivating effect such medication can have, conclude Mayer et al.


About NASS
The North American Spine Society (NASS) is a multidisciplinary organization that advances quality spine care through education, research and advocacy. NASS members are MDs, DOs and PhDs in 22 spine-related specialties including orthopedics, neurosurgery, physiatry, pain management and other disciplines. Nurse practitioners, physicians assistants, chiropractors, physical therapists, practice administrators and other allied health care professionals involved in spine care are also represented in NASS as affiliate members.  For more information on spine care or to find a spine specialist in your area, please contact 1-877-SPINE-DR or visit www.spine.org .