




Healthcare Industry News: Magnetic Resonance Imaging
News Release - July 5, 2006
Four-Year Follow-up Study Shows Intermediate Term Efficacy of New Minimally Invasive X STOP Procedure for Common Cause of Low Back Pain
Journal of Spinal Disorders & Techniques Publishes Clinical Results to Support X STOP for the Treatment of Lumbar Spinal StenosisSAN FRANCISCO--(HSMN NewsFeed)--July 5, 2006--A four-year follow-up study published in the July issue of Journal of Spinal Disorders & Techniques, a prestigious scientific journal, supports previous results that show patients suffering from lumbar spinal stenosis have significantly greater improvement with a new, minimally invasive procedure, the X STOP® Interspinous Process Decompression (IPD®) System ("X STOP") and remained stable over time. These results come on the heels of a recently published study in the Journal of Neurosurgery: Spine that demonstrated the X STOP to have significantly greater clinical success (63.4%) than non-operative care which was found to have a clinical success rate of only 12.9 percent.
Lumbar spinal stenosis (LSS) is a common spinal problem suffered mainly by the middle-aged and elderly population, and results from a narrowing in the lumbar spinal canal that carries nerves to the legs. As this space in the lower spine shrinks, the nerves that go through it are squeezed, causing debilitating pain in the back, legs and buttocks. LSS is the most common reason for back surgery in people over the age of 50 in the United States.(1) In 1995 it was reported that 1.2 million physicians' office visits were related to symptoms of LSS(2), this number is over 2 million today.(3)
"These trial results further support the clinical success of the X STOP and prove that the procedure is well-positioned to become the first-line surgical intervention for LSS patients," said Kevin Sidow, president and chief executive officer of St. Francis Medical Technologies. "Not only do patients now have a minimally invasive option that has shown to provide better outcomes than other treatment alternatives, but results have remained stable over time."
Methodology:
The current study presents four-year clinical follow-up data on a cohort of patients (n=23) treated at one center that was part of a randomized, controlled multicenter trial (n=191) comparing the outcomes of neurogenic intermittent claudication (NIC) in patients treated with the X STOP and patients treated non-operatively. All of the 23 subjects who were enrolled in the X STOP pivotal trial at St. Mary's Spine Center were screened for eligibility. Eighteen patients were identified as eligible and willing to participate. The average length of follow-up was 51 months (range 45-61) and the average age at the time of the operation was 67 years.
All centers that had participated in the X STOP pivotal trial had Institutional Review Board (IRB) approval and were designated as Investigational Study Centers under IDE approval by the Food and Drug Administration (FDA).
To be included in the pivotal trial, patients had to be above the age of 50, and had leg, buttock or groin pain with or without back pain that was relieved by sitting or flexion. Patients were excluded if they could not walk at least 50 feet and/or were unable to sit for at least 50 minutes. Additionally, patients were excluded if they had fixed motor deficit, cauda equine syndrome, previous lumbar surgery of the stenotic level or spondylolisthesis greater than grade 1 at the affected level.
Study Results:
The mean preoperative Oswestry Disability Index (ODI) score was 45 (range 20 to 80). The mean postoperative ODI score was 15 (range 0 to 36), and the mean improvement score was 29. Using a 15-point improvement from baseline ODI score as a success criterion, 14 out of 18 patients had successful outcomes at long-term follow up. This equals a 78 percent success rate.
About the X STOP:
The X STOP® Interspinous Process Decompression (IPD®) System ("X STOP") is a titanium alloy implant that was approved by the FDA in November 2005 as the first and only non-fusion treatment to improve symptom severity and physical function for patients with LSS. X STOP fills a gap in the continuum of care for LSS sufferers that, until now, required patients to leap from conservative therapies, such as analgesics and injections, straight to laminectomy, an invasive procedure that is considered the current surgical standard of care. Clinically proven to relieve patients' symptoms, the X STOP procedure is well poised to become the first-line surgical intervention for LSS patients.
Inserted through a small incision, the X STOP is placed between two bones called spinous processes of the symptomatic discs in the low back. The X STOP is designed to limit extension of the lumbar spine, and keep open the canal in the lower spine that carries nerves to the legs, thereby relieving symptoms.
The device can be surgically implanted in a minimally invasive procedure that is typically performed with local anesthesia in less than an hour. As it is not fixed to any bony structures, the X STOP procedure does not result in fusion and is completely reversible without compromising any therapeutic alternatives, including laminectomy.
The X STOP has been commercially available in Europe and Japan since 2001, and more than an estimated 7,000 X STOP devices have been implanted worldwide.
About St. Francis Medical Technologies' Clinical Leadership:
The results of the FDA pivotal trial that led to the FDA approval of the X STOP in November 2005, as well as other clinical studies, have been published in several prestigious journals.
- Anderson, P., et al., Treatment of neurogenic claudication by interspinous decompression: application of the X STOP device in patients with lumbar degenerative spondylolisthesis. J Neurosurg Spine, 2006. 4:463-471,
- Heijnen, S. and F. Kramer, Spinal Distraction as Therapy for Lumbar Spinal Stenosis - The First Results. Dutch Orthopedic Journal, 2005: p. 199- 203.
- Lee, J., et al., An interspinous process distractor (X STOP) for lumbar spinal stenosis in elderly patients: preliminary experiences in 10 consecutive cases. J Spinal Disord Tech, 2004. 17(1): p. 72-7; discussion 78.
- Zucherman, J.F., et al., A Multicenter, Prospective, Randomized Trial Evaluating the X STOP Interspinous Process Decompression System for the Treatment of Neurogenic Intermittent Claudication: Two-Year Follow-Up Results. Spine, 2005. 30(12): p. 1351-1358.
- Siddiqui, M., et al., The positional Magnetic Resonance Imaging changes in the lumbar spine following insertion of a novel interspinous process distraction device. Spine, 2005. 30(23): p. 2677-82.
St. Francis Medical Technologies is a privately held company based in Alameda, CA., engaged in the discovery, development, manufacturing and marketing of novel treatments for degenerative spinal disorders worldwide. In November 2005, St. Francis received FDA approval for the X STOP, the first FDA-approved interspinous process implant to treat Lumbar Spinal Stenosis (LSS), a degenerative spinal disorder that may affect over two million Americans. As a result, patients and healthcare professionals finally have a safe and effective alternative to more aggressive, riskier procedures. For more information, please visit: www.sfmt.com.
(1) The Center for the Evaluative Clinical Sciences, Dartmouth Medical School. The Dartmouth Atlas of Musculoskeletal Health Care. The Trustees of Dartmouth College, 2000
(2) The Hart LG, Deyo RA, Cherkin DC. Physician office visits for low back pain. Frequency, clinical evaluation, and treatment patterns from a U.S. national survey. Spine 1995;20:11-9.
(3) The Ortho FactBook(TM); U.S. 5th Edition; Solucient, LLC and Verispan, LLC
Source: St. Francis Medical Technologies
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