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• Spinal motion preservation (1)
  
• Bone morphogenic protein
  • Medtronic Sofamor Danek
    • Infuse (1)
  • Stenosis
    • Cervical
    • Lumbar
• Interspinous decompression OR Interspinous spacers
• Abbott Spine
  • Wallis System
• Medtronic Sofamor Danek
  • Diam (2)
• minimally invasive
• NuVasive (1)
• Paradyme Spine
  • Coflex
• St. Frances Medical
  • X-Stop
  • X-Stop ["Peek"]
• Posterior Dynamic Stabilization Systems OR Pedicle Screws (5)
  • Abbott Spine
    • DSS
  • Applied Spine Technologies
    • StabilimaxNZ (1)
  • Globus Medical
    • Protex
  • Innovative Spinal Technologies
    • Micromotion
    • Full Motion Systems
  • Mekanika
    • Modulus
  • N Spine (1)
    • N flex
  • Scient'X
    • Isobar TTL
  • Zimmer Spine
    • Dynesys
• Total disc replacement OR TDR AND
  • Cervical
  • Lumbar (1)
  • DePuy Spine (J&J)
    • SB Charite III (1)
  • Medtronic Sofamor Danek
    • Maverik
  • Synthes
    • ProDisc L (1)

(A small sampling of results from a December 15, 2006 - January 15, 2007 MIB Abstract Alert search)

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Hybrid multidirectional test method to evaluate spinal adjacent-level effects.

News published by Medtronic officials updates activities

Medtronic; Officials from Medtronic report latest developments

Medtronic Announces First DIAM(TM) Spinal Stabilization System Surgeries in European Post Market Study

NuVasive announces senior management promotions

Legal Issues; Medtronic wins appeals court ruling on patent for largest pedicle screw lines

Groundbreaking spine surgery at U. 'a miracle'

South Korean Inventor Develops Spine Flexible Fixation System

UNIVERSITY OF NORTH CAROLINA, U.S.; Studies from University of North Carolina, U.S., highlight most recent research

Polyethylene wear debris and long-term clinical failure of the Charite disc prosthesis: a study of 4 patients

UNIVERSITY OF NORTH CAROLINA, U.S.; Studies from University of North Carolina, U.S., highlight most recent research

Hybrid multidirectional test method to evaluate spinal adjacent-level effects.

Clin Biomech (Bristol, Avon). 2006 Dec 28; [Epub ahead of print]

Panjabi MM

Biomechanics Research Laboratory, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, P.O. Box 208071, New Haven, CT 06520-8071, USA.

BACKGROUND: Several clinical studies have documented long-term adjacent-level effects of spinal fusion, due to stress concentration and motion loss at the fused segment. Non-fusion motion preservation devices are designed to eliminate or slow down such adverse effects. Therefore, appropriate biomechanical evaluation of the adjacent-level effects in spine is important and timely. Although many biomechanical studies are available and have provided some understanding of the adjacent-level effects, results have large variation and are conflicting, mostly due to the use of inappropriate and ill-defined methods. A new test method especially designed to study spinal adjacent-level effects is needed. METHODS: The proposed Hybrid method uses unconstrained pure moment to provide rotation-input for multi-directional testing. The new method has four steps: (1) Intact spine specimen with entire mobile region is used. The specimen is prepared to measure various biomechanical parameters, e.g., disc pressures, ligament strains, and facet loads. (2) Appropriate unconstrained pure moment is applied to the intact specimen and total range of motion is determined. (3) Unconstrained pure moment is applied to the spinal construct (specimen with an implant) until the total range of motion of the construct equals that of the intact. (4) Statistical comparison of the biomechanical parameters between the construct and intact quantifies the adjacent-level effects. FINDINGS: The uniqueness of the proposed method, to study the adjacent level effects due to fusion and non-fusion devices, is that it applies the needed rotation-input to the spine specimen, using available methodology with minimal modification. INTERPRETATION: Previous studies have lacked appropriate and well-defined methodologies to evaluate spinal adjacent-level effects. The proposed method uses well-known methodology and yields high quality, and laboratory-independent results for the fusion and non-fusion devices.

PreMedline Identifier: 17196720

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News published by Medtronic officials updates activities

Hospital Business Week, December 31, 2006

Medtronic, Inc. (MDT) announced that the U.S. Food and Drug Administration (FDA) has granted an investigational device exemption (IDE) to conduct a clinical trial to study Infuse bone graft in a cervical spinal fusion.

The investigational device will consist of Infuse bone graft inside a polyetheretherketone (PEEK) polymer interbody spacer used with an anterior cervical plate as a method of facilitating spinal fusion. The goal of the clinical trial is to evaluate whether Infuse bone graft is a safe and effective alternative to traditional bone grafting techniques for cervical spine fusions.

In the United States, more than 200,000 individuals undergo spine fusions to treat degenerative changes in the cervical spine.

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Medtronic; Officials from Medtronic report latest developments

Pharma Business Week. Atlanta: Dec 25, 2006. pg. 535

Medtronic, Inc. (MDT) announced that the U.S. Food and Drug Administration (FDA) has granted an investigational device exemption (IDE) to the DIAM Spinal Stabilization System for use in a clinical study.

This approval will allow Medtronic to begin the first of three planned clinical trials in the U.S. and Europe. The DIAM System is designed to alleviate pain in degenerative stenosis patients who suffer predominantly from radiating leg discomfort and moderate low back pain and is the only non-rigid interspinous spacer under clinical investigation.

The initial Medtronic study will examine the safety and effectiveness of the DIAM System when used to treat patients with degenerative stenosis. Degenerative stenosis is a common condition in the aging process, marked by the gradual narrowing of the spinal canal, resulting in pressure on the spinal cord or nerve roots.

Degenerative stenosis affects more than 250,000 U.S. patients each year. Stenotic spine patients with radiating leg pain or numbness typically undergo decompression surgery alone. Patients with both leg and back pain normally have a decompression surgery with fusion. The purpose of decompression surgery is to release excess pressure by creating more space in the spinal canal. Combined with decompression, the DIAM System could offer patients with leg and back pain a minimally invasive alternative to spinal fusion.

The implant is placed between the spinous processes (the visible ridges of the back) to act as a shock absorber that reduces loads on the surrounding vertebrae and restores the natural function of the joint. The core of the DIAM System is made of silicone, while the outer mesh and tethers are made of medical-grade polyester. The flexible properties of the DIAM materials may also protect the integrity of the spinous process.

Proquest Identifier: 1183484451
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Medtronic Announces First DIAM(TM) Spinal Stabilization System Surgeries in European Post Market Study

Business Wire. New York: Dec 18, 2006. pg. n/a

Medtronic, Inc. (NYSE: MDT) today announced the enrollment of the first two patients in the European post market clinical study using the DIAM(TM) Spinal Stabilization System. The first two surgeries were performed on Nov. 24 by Dr. Gianluca Maestretti of the Hopital Cantonal Fribourg, Switzerland, and Dr. Ferdinand Krappel of the Medizinisches Zentrum Kreis Aachen, Wuerselen, Germany.

These surgeries are part of a randomized, controlled clinical trial that is comparing Medtronic's DIAM Spinal Stabilization System to a standard disc herniectomy. The DIAM Spinal Stabilization System is currently affixed with a CE Mark and available for distribution in the European market, but not approved for use in the U.S. Evidence collected from this trial will be used to improve treatment decisions for better patient outcomes. Patients are being randomized into either an investigational group, consisting of a herniectomy supplemented by the DIAM Spinal Stabilization System, or a control group, consisting of patients who will undergo a standard herniectomy. Herniectomy is the standard of care for addressing leg pain caused by disc herniation. When combined with a standard herniectomy, the DIAM Spinal Stabilization System may result in a therapy solution that provides both leg and back pain relief for the patient.

The DIAM Spinal Stabilization System implant is placed between the spinous processes (the visible ridges of the back) and is designed to act as a shock absorber that reduces weight on the surrounding vertebrae. The core of the DIAM System is made of medical-grade silicone, while the outer mesh and tethers are made of polyester. The flexible properties of the DIAM System materials may also protect the integrity of the spinous process.

Patients will be evaluated for differences in pain relief, physical disability and quality of life as well as further progression of their disc disease. The study is assessing the short and long-term effectiveness and patient perception of benefit with the use of the DIAM Spinal Stabilization System in the treatment of complex disc disease. This is a multicentre study with 20 investigational centres within Western Europe.

Additional information on back pain and the DIAM Spinal Stabilization System can be found at www.back.com/clinicaltrial.

About the Spinal Business at Medtronic

The Spinal business at Medtronic, based in Memphis, Tenn., is the global leader in today's spine market and is committed to advancing the treatment of spinal conditions. The Spinal business collaborates with world-renowned surgeons, researchers and innovative partners to offer state-of-the-art products and technologies for neurological, orthopedic and spinal conditions. Medtronic is committed to developing affordable, minimally invasive procedures that provide lifestyle friendly surgical therapies. More information about the company and its spinal treatments can be found at www.medtronicspinal.com and its patient-education Web sites, www.back.com, www.iscoliosis.com, www.maturespine.com and www.necksurgery.com.

About Medtronic

Medtronic, Inc. (www.medtronic.com), headquartered in Minneapolis, is the global leader in medical technology - alleviating pain, restoring health, and extending life for millions of people around the world.

Any forward-looking statements are subject to risks and uncertainties such as those described in Medtronic's Annual Report on Form 10-K for the year ended April 28, 2006. Actual results may differ materially from anticipated results.

Proquest Identifier: 1182506821
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NuVasive announces senior management promotions

Lab Business Week, December 17, 2006

NuVasive, Inc. (NUVA) announced several management promotions designed to provide continued support and leadership for the company's growth.

The company also announced that Alexis Lukianov continues in his leadership role as chairman and chief executive officer.

Lukianov has served as chief executive officer and a member of NuVasive's Board of Directors since January 1999. With more than 20 years of experience in the orthopedic industry, Lukianov has guided NuVasive in building a reputation as a leading provider of creative technology to enable minimally disruptive spine surgery. Lukianov will continue to work closely with NuVasive's entire management team to establish and refine the company's strategy and ensure operational focus.

The promotions include the following four current executives who will be filling expanded roles:

Keith Valentine has been promoted to president and chief operating officer. Patrick Miles has been promoted to executive vice president of Marketing and Development. Jason Hannon has been promoted to senior vice president and general counsel. G. Bryan Cornwall, PhD has been promoted to the position of vice president of Research and Clinical Resources.

Nuvasive is a medical device company.

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Legal Issues; Medtronic wins appeals court ruling on patent for largest pedicle screw lines

Managed Care Weekly Digest. Atlanta: Dec 18, 2006. pg. 84

2006 DEC 18 - (NewsRx.com) -- Medtronic, Inc. (MDT) announced that in the case of DePuy Spine, Inc. and Biedermann Motech GMBH v. Medtronic Sofamor Danek, Inc. the U.S. Court of Appeals for the Federal Circuit affirmed the decision of the District Court of Massachusetts that Medtronic's CD Horizon M8 and CD Horizn M10 multi axial screws do not infringe the DePuy '678 patent.

This decision also applies to Medtronic's CD Horizon Legacy multi axial screws. These products are some of Medtronic's largest selling spinal products and this decision means Medtronic will continue to supply them to surgeon customers.

The U.S. Court of Appeals also affirmed the District Court's determination that Vertex reconstruction system screws, for use in the upper thoracic spine, do not literally infringe the '678 patent, but ruled that there is an issue of fact as to infringement under the doctrine of equivalents that can proceed to trial. Medtronic is confidant in its position on the Vertex system and expects to prevail in a jury trial.

The court affirmed the jury's verdict that Medtronic's old-style CD Horizon MAS products, which are no longer sold in the U.S., infringed under the doctrine of equivalents. The company had previously reserved the $24.3 million judgment entered upon the jury's verdict.

Medtronic, Inc. is headquartered in Minneapolis, Minnesota

Proquest Identifier: 1179309301
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LOUISIANA STATE UNIVERSITY, U.S.; Recent research from Louisiana State University, U.S., summarized

Life Science Weekly, December 19, 2006

Surgical techniques using anatomic landmarks versus open laminectomy in lumbar fusion were compared in cadaveric specimens.

"We determined whether the accuracy of lumbar pedicle screw placement is optimized by performing a laminectomy before screw placement with screw entry point and trajectory being guided by pedicle visualization and palpation (Technique 1). This technique was compared with a technique using anatomic landmarks for pedicle screw placement (Technique 2)," wrote A. Karim and colleagues, Louisiana State University.

They continued, "The biomechanical stability of the instrumented constructs, in the absence and presence of a laminectomy, was also compared. Twelve L1-L3 specimens were harvested from fresh cadavers. The intact laminectomy and instrumented spines were biomechanically tested in flexion and extension, lateral bending, and axial rotation.

"Laminectomies were performed in 6 of the 12 specimens before pedicle screw placement using technique 1. The remaining six specimens underwent pedicle screw and rod fixation using technique 2. Computed tomographic images were obtained for all instrumented specimens. Deviation of the screws from the ideal entry point or trajectory was analyzed to quantitatively compare the two techniques."

The researchers explained, "Computed tomographic analysis of the specimens showed that all screw placements were within the pedicles. Scatter plot analysis demonstrated that screws placed using technique 2 were more likely to have the combination of entry points and trajectories medial to the ideal entry point and trajectory. Laminectomy did not weaken the final pedicle screw and rod-fixated constructs. All screw placements were grossly within the confines of the pedicles, regardless of technique, as evidenced by computed tomographic analysis."

The team concluded, "Furthermore, the anatomic landmark technique and the open laminectomy technique yielded biomechanically equivalent pedicle screw and rod-fixated constructs."

Karim and colleagues published their study in Neurosurgery (Accuracy of pedicle screw placement for lumbar fusion using anatomic landmarks versus open laminectomy: A comparison of two surgical techniques in cadaveric specimens. Neurosurgery, 2006;59(1 Suppl. S):13-19).

For additional information, contact A. Nanda, Louisiana State University, Dept. of Neurosurgery, Health Science Center, 1501 Kings Highway, POB 33932, Shreveport, LA 71130, USA.

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FUKUSHIMA MEDICAL UNIVERSITY, JAPAN; Fukushima Medical University, Japan, investigators have published new study data

Life Science Weekly, December 19, 2006

The Graf pedicle screw and ligament device eventually leads to successful fusion of the spine in patients with lumbar degenerative disease.

According to recent research from Japan, "The Graf pedicle screw and ligament device is designed to provide flexible stabilization to prevent abnormal spinal movement. The purpose of this study was to investigate radiographic and clinical outcomes during a minimal 5-year follow-up period. Between 1991 and 1997, 43 consecutive patients (whose mean age was 61 years) with lumbar degenerative disease underwent decompression and stabilization in which the Graf system was placed."

A. Onda and colleagues, Fukushima Medical University, wrote, "Data were available for 31 patients who attended follow up for the minimal 5-year period. In a retrospective review, the authors assessed measurements on radiographs, clinical results (using Japanese Orthopaedic Association [JOA] Scale scores), and low-back pain (using a visual analog scale [VAS] score), preoperatively and postoperatively at 1, 3, 5, and/or 10 years. Radiographic measurements included sagittal and frontal range of motion (ROM), regional lordosis, and posterior disc height as well as the extent of degenerative spondylolisthesis."

They continued, "Final follow-up JOA and VAS scores were significantly better than preoperative scores. Sagittal and frontal ROM was significantly reduced at 1 and 5 years, respectively, compared with preoperative values, and a gradual reduction persisted throughout the follow-up period. Compared with its preoperative status, the disc height ratio (adjacent segments to the operated level) was reduced 5 years after surgery. A significant inhibition of the vertebral slippage was detected only in the flexion position. Analysis of these data indicated that the Graf system eventually leads to successful fusion, suggesting the presence of stability in all three dimensions."

The researchers concluded, "The use of the Graf system should continue to be evaluated as an alternative device in the treatment of lumbar degenerative disease."

Onda and colleagues published their study in the Journal of Neurosurgery (Mid-term and long-term follow-up data after placement of the Graf stabilization system for lumbar degenerative disorders. J Neurosurg Spine, 2006;5(1):26-32).

For additional information, contact A. Onda, Fukushima Medical University, School of Medicine, Dept. of Orthopedic Surgery, 1 Hikarigaoka, Fukushima 9601295, Japan.

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SURGICAL TECHNOLOGY; LDR receives U.S. Food and Drug Administration 510(k) clearance for LP Multiaxial Screw

Medical Devices & Surgical Technology Week, December 31, 2006

LDR, a total spine solution company, announced that it has obtained 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market its LP Multiaxial Screw.

According to the company, the LP Screw adds flexibility to the Easyspine Pedicle Screw System allowing 70 degrees of movement in all planes, while simplifying spondylolisthesis reduction and offset screw placement.

The LP Screw performs a spondylolisthesis reduction in two stages with very minimal instrumentation. During boney reduction, the LP is driven into the bone, pulling the vertebra toward the rod. Final mechanical reduction allows 6-10 mm of calibrated adjustment during locking of the integrated locking nut.

Dr. Kee Kim of the University of California-Davis Medical Center was the first in the U.S. to implant an LP Screw. Kim commented, "It is important for surgeons to have multiple options when doing lumbar fusion surgery. The addition of the LP Screw strengthens an already innovative fusion product line by adding an offset option along with a simple way to do a solid spondylolisthesis reduction."

The LP Screw contains one multiaxial and one polyaxial connection: the head-to-rod connection and the head-to-shaft connection. Both connection points lock independently for maximum adjustability. This combined connection design creates the range of motion of 70 degrees, the company says. The distance from the screw shaft to rod provides a built-in offset of 10 mm.

The company states Easyspine was first introduced in 2002 and has been used in over 10,000 cases worldwide. Designed in close cooperation with leading spine surgeons, Easyspine features a simplified surgical technique and adaptable implants to accommodate varied pathologies.

LDR works closely with surgeons to develop implantable spine systems and instrumentation that restore optimum stability and mobility to patients and to make spine surgery more reproducible and easier to perform.

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ORTHOFIX INTERNATIONAL; News published by Orthofix International officials updates activities

Surgery Litigation & Law Weekly, December 15, 2006

Orthofix International N.V. (OFIX) has signed an agreement to buy Blackstone Medical, Inc., a spinal implant company.

The US$333 million acquisition allows Orthofix to leverage Blackstone's engineering vitality, established "Breakthrough Thinking" brand identity, and their market strength in the fusion, motion preservation and biologics categories. Blackstone has experienced profitable revenue growth of more than 25% in each of the last 3 years, and total revenue increased 39% during the first half of this year. Combining both companies' strengths into a synergistic powerhouse will bring greater innovation to orthopedics on a global level.

Blackstone's highly regarded and well-earned research and development capabilities have resulted in the launch of 14 new products in the last 2 years. Blackstone is the first spinal company to make technological leaps and bounds with the introduction of Trinity Multipotential Cellular Bone Matrix, the only commercially produced "adult stem cell" biologics product for bone growth in the spine. Other new innovations include the ICON Modular Spinal Fixation System, an advanced modular pedicle screw, that together with the ProView Minimally Invasive System, offers greater latitude for surgeons performing minimally invasive surgery. Additionally, the Advent Artificial Cervical Disc slated for European Union (E.U.) release in the first quarter of 2007, marks serious progress for motion preservation as it closely mimics the natural range of human motion.

Orthofix recognizes the potential for joining forces. "This acquisition is a transformational event for Orthofix and a major step in our strategy, as it establishes a solid platform for accelerated sales and earnings expansion in the fastest growing segment of the orthopedics industry," said Orthofix CEO Alan Milinazzo. "Our robust distribution channels give us the opportunity to significantly expand the availability of Blackstone's unique product portfolio around the world."

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Groundbreaking spine surgery at U. 'a miracle'

The Salt Lake Tribune. Salt Lake City, Utah: Jan 15, 2007. pg. n.a

Jane Grau

In November, a new device offering an alternative to spinal fusion was approved by the Food and Drug Administration. The next day, surgeons at University of Utah Hospital performed the country's first implant of the Stabilimax Bar Spine Stabilization System.

Ernest Korgenski, 80, of Holladay, was an ideal candidate for this procedure. Korgenski, who spent about a year and a half virtually immobilized with pain, had a pinched nerve caused by spinal degeneration. The usual treatment would be to open up the area that had collapsed around the nerves and fuse the bones in such a way as to keep them apart.

But University of Utah neurosurgeon Ken Yonemura is on the scientific advisory board for Applied Spine Technologies, the New Haven, Conn., company that manufactures Stabilimax - which led to its first use at the U.

The device consists of three main parts: two screws and a connecting rod made of titanium and a cobalt chrome alloy - two durable metals - that are put together to look like the two uprights on a goalpost with a sliding crossbar between them.

Instead of welding two vertebrae together so they move as one, making for a rigid backbone, the separate screws are put into adjoining vertebrae and the rod slides through sleeves on top of the screws. Thus the bones are still able to move independently of each other while they are kept from getting out of alignment.

A bonus side effect: the bone and tissue above and below the level of stabilization will deteriorate at a slower rate. The whole spine, in other words, will strengthen instead of weaken. This pleases Andrew Dailey, the associate professor of neurosurgery at U. of U. Hospital who performed the operation.

"I'm tired of seeing fusion disease," he said.

Aging, aching backs: Back pain is the largest cause of visits to the doctor in the United States, with 80 percent of the population experiencing some kind of back problem in their lifetimes.

"The condition of your back," said Dailey, "depends on how your body is put together and what you do to it."

The likelihood of back pain increases with age, when bones become soft, tissues deteriorate, discs bulge, vertebrae rub against each other and nerves get pinched. The last causes pain, sometimes so severe that people can't walk for more than a few minutes.

Fusion - when two or more vertebrae are surgically welded together - is recommended as a way of stabilizing the spine and stopping the progress of deformities such as scoliosis. It's pretty much a last resort, but when you can't walk because your legs hurt, it's a viable one.

Recovery from spinal fusion takes three to four months, requires learning how to move properly, involves a cast or brace, and, usually, the loss of the ability to bend and twist. Despite its drawbacks, over 300,00 spinal fusions are performed each year.

Stabilimax offers a less-invasive alternative that stabilizes the spine, keeps it mobile, prevents further deterioration and requires only a couple days of recuperation before the patient can walk again, said Dailey.

Korgenski's implant represents a culmination of over 30 years of research. The head of the project was Manohar Panjabi, a retired professor of orthopedics and rehabilitation at Yale University known for his work on spinal joint function.

'I had no pain': Candidates for Stabilimax are people over 65 who suffer from conditions such as scoliosis, arthritis and herniated discs.

Back pain sufferers who are not good candidates for Stabilimax implants are those whose bones are too soft.

"I had the right make-up for this to happen," Korgenski said. "The doctor told me I had bones as hard as any he's seen in an 80 year old."

Before the surgery, "I was really struggling," Korgenski said. "I had leg pain so severe I could only walk a few steps, keeping stable by touching a wall or something."

The implant operation takes three to four hours at this stage.

"The results are 100 percent," said Korgenski. "The minute I was out of the OR, I had no pain in my legs. I've been walking upright. I haven't had a pain pill for weeks. I told the doctor he performed a miracle."

Sometimes, several procedures, such as a combination of disc replacement, fusion and Stabilimax, are called for.

While artificial knee and hip joints take a lot of wear and tear, causing them to have to be replaced about every 10 years, back mechanisms may last as long as 20 or 30 years because the load on them is lighter.

Expectations are that the more proficient surgeons become with the procedure, operating time will be reduced. Risks are the same as with other back surgery: primarily, injury to nerve routes during surgery and infection.

"We'll be following patients closely to see how our theories do over time," said Dailey. "We're in a learning curve with the long term, but the short term result is success."

---

* JANE GRAU can be contacted at jgrau@sltrib.com or 801-257- 8694. Send comments about this story to livingeditor@sltrib.com.

"The results are 100 percent. The minute I was out of the OR, I had no pain in my legs. I've been walking upright. I haven't had a pain pill for weeks. I told the doctor he performed a miracle."

ERNEST KORGENSKI

Touting the Stabilimax system

A new way to repair lumbar discs, a delicate area of the spine, also debuted at University Hospital in November.

Neurosurgeon Kenneth Yonemura, who performed the procedure, describes Xclose as an improvement over what had been a less-than- ideal method for repairing an incision or tear in lumbar discs.

Because closing with ordinary needles and sutures carries the risk of damaging nearby nerves, incisions have been left to scar over. Xclose involves a specially-designed, disposable surgical tool that surgeons use to cross-stitch dacron thread over a wound so that it heals smoothly, without creating excess scar tissue.

"Scar tissue is never as strong as original tissue," explained Yonemura, so a stronger, cleaner repair greatly reduces the chances of re-injury, pain and further surgery.

"This is the first reliable way of closing a disc opening," he said.

The Xclose technique will most commonly be used with the surgical correction of herniated discs, a common cause of low back and leg pain. Discs, which cushion the vertebrae of the spine, can rupture, bulge or slip. This leads to pinched nerves that cause pain and impair movement.

According to Anulex Technologies, the developer of Xclose, four out of five people experience such pain and the resulting disability in their lifetimes. Surgery removes damaged material from inside the disc.

- Jane Grau

Proquest Identifier: 1194927951
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South Korean Inventor Develops Spine Flexible Fixation System

US Fed News Service, Including US State News. Washington, D.C.: Dec 26, 2006. pg. n/a

ALEXANDRIA, Va., Dec. 26 -- Tae-ahn Jahng of Iksan, South Korea, has developed a method and a system for marking and guiding the insertion of securing members (e.g., pedicle screws) of a spinal fixation device.

An abstract of the invention, released by the U.S. Patent & Trademark Office, said: "In one embodiment, the marking and guidance method and system includes the use of a guide tube configured to be inserted into a patient's back until a first end reaches an entry point on or near a vertebral bone of the patient's spinal column, wherein the guide tube includes a hollow cylindrical channel along its longitudinal center axis; a penetrating device configured to be positioned within the cylindrical channel of the guide tube and having a sharp tip configured to protrude outwardly from the first end of the guide tube so as to allow the first end of the guide tube to penetrate through the patient's back muscle and tissue and reach the vertebral bone at the entry point; a marking pin configured to be inserted through the cylindrical channel of the guide tube, after removal of the penetrating device, until a first end of the marking pin having a sharp tip reaches the entry point; and a pushing device configured to be inserted through the cylindrical channel of the guide tube and provide a driving force at a second end of the marking pin, opposite the first end, so as to drive and secure the first end of the marking pin into the vertebral bone, wherein the marking pin identifies the location of the entry point on the vertebral bone for subsequent implantation of a securing member of a spinal fixation device."

The inventor was issued U.S. Patent No. 7,137,985 on Nov. 21.

The patent has been assigned to N Spine Inc., San Diego.

For more information about US Fed News federal patent awards please contact: Myron Struck, Managing Editor/US Bureau, US Fed News, Direct: 703/866-4708, Cell: 703/304-1897, Myron@targetednews.com.

Call 800/786-9199 (in the U.S. or Canada) or 703/308-4357 for assistance from a U.S. Patent & Trademark Office Customer Service Representatives and/or access to the automated information message system.

Proquest Identifier: 1185588781
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UNIVERSITY OF NORTH CAROLINA, U.S.; Studies from University of North Carolina, U.S., highlight most recent research

Science Letter, December 19, 2006

Range of motion (ROM) measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar total disc replacement (TDR) radiographs.

According to recent research from the United States, "A retrospective review of lumbar TDR radiographs was conducted to determine the error and variability in measuring TDR radiographic ROM."

M.R. Lim and colleagues, University of North Carolina, wrote, "Motion preservation is the driving force behind lumbar TDR technology. In the recent literature, sagittal radiographic TDR ROM as low as 2 degrees has been reported. In these studies, ROM was determined by using the Cobb method to measure TDR sagittal alignment angles in flexion-extension lateral radiographs. However, previous studies in the spinal deformity literature have shown that the Cobb method is very susceptible to measurement error.

"There were 5 observers, including 2 attending orthopedic spine surgeons, 1 spine fellow, 1 fifth-year resident, and 1 fourth-year resident, who measured the ROM of 50 ProDisc II (Synthes Spine Solutions, New York, NY) TDRs on standard flexion-extension lumbar spine radiograph sets. Repeated measurements were made on 2 occasions using the Cobb method. Measurement variability was calculated using 3 statistical methods."

They continued, "The 3 statistical methods resulted in extremely similar values for TDR ROM observer variability. Overall, the intraobserver variability of TDR ROM measurement was ±4.6 degrees, and interobserver variability was ±5.2 degrees. To be 95% certain that an implanted TDR prosthesis has any sagittal motion, a ROM of at least 4.6 degrees must be observed, which is the upper limit of intraobserver measurement variability for a TDR with a true ROM of 0 degrees. To be 95% certain that a change in TDR ROM has occurred between 2 measurements by the same observer, a change in ROM of at least 9.6 degrees must be observed (the entire range of ±4.6 degrees intraobserver variability)."

The researchers concluded, "ROM measurement variability should be considered when evaluating the success or failure of motion preservation in lumbar TDR."

Lim and colleagues published their study in Spine (Measurement error of lumbar total disc replacement range of motion. Spine, 2006;31(10):E291-E297).

For additional information, contact M.R. Lim, University of North Carolina, Dept. Orthopedic Surgery, CB 7055, 3152 Bioinformatics Bldg, Chapel Hill, NC 27599, USA.

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Polyethylene wear debris and long-term clinical failure of the Charite disc prosthesis: a study of 4 patients.

Spine. 2007 Jan 15;32(2):223-9.

van Ooij A, Kurtz SM, Stessels F, Noten H, van Rhijn L.

Department of Orthopaedic Surgery, University Hospital Maastricht, Maastricht, The Netherlands. avoo@sort.azm.nl

STUDY DESIGN: A clinical case series of 4 patients undergoing anterior lumbar revision due to failure of total disc replacement surgery. OBJECTIVES: To assess the clinical significance of polyethylene wear debris in salvage surgery after initial total disc replacement, the pattern and the mechanisms of polyethylene wear in the retrieved cores, and the extent of polyethylene debris in the periprosthetic tissues obtained from 4 patients. SUMMARY OF BACKGROUND DATA: Previous in vitro wear tests have demonstrated low wear rates for lumbar artificial discs, suggesting that implant wear may not be a clinically relevant issue with total disc replacement. However, only long-term clinical investigations with analysis of retrieved implants and periprosthetic tissue can ultimately establish the significance of polyethylene wear debris for total disc arthroplasty. METHODS: Starting in 2004, we began routinely performing salvage procedures in patients with failed total disc replacements. We report on the short-term outcomes of 4 patients at our institution who were revised with a Charite prosthesis (DePuy Spine, Raynham, MA). Wear analysis of the retrieved prosthesis and histologic examination of the periprosthetic tissue were also performed. RESULTS: All of the retrieved polyethylene cores showed evidence of wear, but the extent and severity varied among the 4 patients. Wear and fracture of the core were associated with osteolysis of the underlying sacrum in 1 patient. Histologic examination of the periprosthetic tissues confirmed the presence of wear debris lying in inflammatory fibrous tissue. In 3 of the 4 patients, implant wear was associated with an unfavorable biomechanical environment (e.g., subsidence, migration, undersizing, and adjacent fusion). The mechanisms of wear included adhesive/abrasive wear of the central domed region of the polyethylene core, as well as chronic rim impingement, resulting in rim fatigue and fracture. CONCLUSIONS: This study demonstrates the clinical significance of polyethylene wear debris and the potential for osteolysis with total disc replacements. The authors recommend that patients undergoing lumbar disc arthroplasty receive long-term follow-up to monitor the wear and functional status of their implants.

PreMedline Identifier: 17224818

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UNIVERSITY OF NORTH CAROLINA, U.S.; Studies from University of North Carolina, U.S., highlight most recent research

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