Each month the newsletter features a partial record from ASM’s acclaimed database, Materials for Medical Devices, which includes a Cardiovascular Module and an Orthopaedic Module. This month’s record comes from the Orthopaedic Module.

Anterior/Anteriolateral Spinal System (General)-Spinal-Orthopaedic Devices
Materials for Medical Devices > Medical Devices

General Information
Device Category: Orthopaedic - Spinal
Device Type: Simple (Possesses one method of function)
Device Generic Name: Appliance, fixation, spinal intervertebral body.

Application
Anterior cervical systems are intended for anterior cervical fixation for the following indications: degenerative disc disease, spondylolisthesis, trauma, spinal stenosis, deformities or curvatures, tumor, pseudarthrosis, and failed previous fusion.

Description
These are anterolateral/anterior systems consisting of rods or plates, staples, screws, washers, endplates, fasteners, etc. The levels of attachment include screw or staple fixation to the anterolateral vertebral bodies of the lumbar and thoracic spine and to the anterior vertebral bodies of the cervical spine.

Deployment Method
In the cervical spine, the plate is often held in place using pins, while the screw holes are drilled and/or tapped if necessary. Screws are inserted through the plate and into the anterior vertebra. A screw-plate locking mechanism, if included, is then implemented. In the anterolateral thoracolumbar spine, the plates are secured to the vertebrae using screws. For a rod-based system, staple plates or washer-like components are first placed on the lateral aspect of the vertebra. The screws are then inserted through these implants and rods are then attached to the screws.
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Matchbox-size neurostimulator offers chronic pain relief


St. Jude Medical, Inc. has received approval from the Australian Therapeutic Goods Administration for the Eon Mini neurostimulator to treat chronic pain of the trunk or limbs and pain from failed back surgery. Approximately the size of a matchbox, the Eon Mini neurostimulator has a thin 10 mm profile and weighs 29 grams (~ 1 oz). The device delivers mild electrical pulses to nerves located near the spinal cord to interrupt or mask pain signals as they travel to the brain and is designed to maintain a reasonable recharge interval for 10 years of use at high settings. The Eon Mini neurostimulation system is also available in the U.S. and Europe.
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ATI expands manufacturing capabilities

Pictured are Allegheny Technologies (ATI, Pittsburgh, Pa.) associates conducting the final conditioning step of surface and dimensional inspection for billet production at the new manufacturing facility in Bakers, N.C. The new facility is part of a $215 million investment to expand ATI’s titanium and nickel base superalloy capabilities to serve the medical, aerospace, and energy industries. The project includes increasing forging capacity with a 10,000 ton press forge and 700 mm rotary forge, adding a fourth plasma arc melt furnace, and a new vacuum arc remelt furnace. The self-funded project is expected to be completed by the end of 2009.
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Polymer film forming system

Particle Sciences Inc. has developed a unique film forming system with applications ranging from tissue hydration to the passivation of medical device surfaces. The system is based on a series of patent-pending polymers that allow customization of the desired contact angle. Clinical results for an ocular formulation being developed for one of its clients are very promising.
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Analysis of premature failure in orthopaedic implants

The most frequent causes of premature failure in orthopaedic implants are inadequate surgical procedures and processing/design errors. In the article “Premature Failure in Orthopedic Implants: Analysis of Three Different Cases,” in the February 2009 issue of Journal of Failure Analysis and Prevention, authors C. Barbosa, J.L. do Nascimento, I.M.V. Caminha, and I.C. Abud show that design errors and improper surgical procedures or outright violation of standards were the cause of the failures. Image: a macrographic view of the fracture site a fractured femoral prostheses showing a mark, probably accidentally introduced by drilling during the implant insertion in the patient body. This mark acted as a stress riser, creating favorable conditions for fatigue crack initiation.

ASM members may subscribe to the Journal of Failure Analysis and Prevention at a special reduced members-only rate. For more information, click here.

For a limited time, this featured article may be freely accessed here.

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Flexible biliary stent receives CE Mark

Flexible Stenting Solutions, Inc. has received the CE Mark (Conformité Européene) for its FlexStent Biliary Self Expanding Stent System. The key to the stent technology is the integration of helically wound struts with helical flexible coils. The company also has submitted Section 510(k) Notification to the U.S. FDA.
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Orfit patient immobilization systems

Orfit Industries develops and manufactures low temperature thermoplastics, hardware, and accessories for patient immobilization and positioning in radiation oncology, helping to deliver high-precision radiation therapy treatment. The carbon fiber base-plate is used with easily interchangeable cushions.
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Fiber optics enhance stent devices

Medical device startup CorNova Inc. takes existing stent-related devices and processes and combines them with fiber optic technology. The company is working on a set of balloon catheters designed to help eliminate stent restenosis, or thrombosis, by helping with stent selection and optimizing the process of implanting the stent.
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The MPMD advantage: Gain materials knowledge that can accelerate development of cardiovascular, neurological, pulmonary, orthopaedic, and dental implants and appliances. Case studies provide practical information. Customized training at your facility is available, too. Contact John Cerne for more information.

Dates and locations:
May 18-21: Fort Wayne, Ind.
June 15-18: Newark, N.J.
August 8-9: Minneapolis, Minn.
November 9-12: Irvine, Calif.

Registration:
$699: ASM member (multiple student discounts apply)
$779: Non-member
$199: Student

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Alternative to heart valve repair and replacement

Mardil (Morrisville, N.C.) treats functional mitral valve regurgitation by addressing the root cause of the condition, a heart muscle that is enlarged and weakened, with its BACE (Basal Annuloplasty of the Cardia Externally) device. Placed around the heart, gentle pressure and support from the BACE Device allow the leaflets of the mitral valve to close properly, thereby preventing blood from leaking backward when the heart pumps. The device is mostly of silicone (~99%) with small amounts of polyester and titanium for attachments to the heart and connecting ports, respectively. Because the device is outside the heart, it is far less invasive than heart valve repair or replacement, avoids the need for open-heart surgery, and the use of a heart-lung bypass machine can be avoided. Also, the risks of thrombosis, stroke, and infection that commonly occur with devices implanted in the heart are reduced.

Clinical trials are underway in India and an application has been made to the FDA for U.S. trials.
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ADMET celebrates 20 years with $30,000 test system giveaway

ADMET Inc., a provider of integrated materials testing systems, is celebrating 20 years in business by offering a free, turnkey biomedical or biomaterials testing system valued at up to $30,000 to a company or university operating in the United States.

The materials testing system will include a universal testing machine, a palm-sized tester or dynamic test system as appropriate for the described project. It will be equipped with ADMET's popular PC-based Materials Testing System, MTESTQuattro, and will include the necessary grips and fixtures for the planned application. For an application and award details, visit the company website. All applications must be received by June 30, 2009.
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MPMD 2009 – Don’t miss your opportunity to shape what happens next!

ASM International’s MPMD is the only medical devices conference that brings together materials scientists and engineers, metallurgists, product designers, researchers, and clinicians. The conference sessions and the exposition are designed to provide the knowledge and networking you need to take advantage of the federal emphasis on biomedical research.

Conference Sessions

• Bioactive / Biomimetic Surfaces and Drug Delivery Systems
• Nanotechnology
• Surface Engineering of Medical Devices
• Advanced Materials and Emerging Technologies
• Fabrication Processes for Medical Devices
• Corrosion, Degradation and Durability
• Effect of Materials on Surgical Techniques
• Materials R&D
• Materials Modeling
• Active Implant Materials
• Regulatory Affairs Related to Materials

Customized medical adhesives from mussels


Using the natural glue that marine mussels use to stick to rocks and a variation on the inkjet printer, a team of researchers led by North Carolina State University (Raleigh, N.C.) has devised a new way of making medical adhesives that could replace traditional sutures and result in faster healing, less scarring, and increased precision for delicate operations.

New research shows that the non-toxic, biodegradable adhesive proteins found in the "glue" produced by marine mussels may be used in place of synthetic adhesives. In addition, the mussel proteins can be placed in solution and applied using inkjet technology to create customized medical adhesives, providing greater control over placement of the adhesive. For example, this technique may significantly improve wound repair in eye surgery, wound closure, and fracture fixation.

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Optical imaging of cells and tissues


The Biomedical Laser Laboratory at East Carolina University (Greenville, N.C.) conducts large-scale numerical modeling and experimental studies of light scattering by biological cells and in tissues. Besides their fundamental importance to the understanding of cell and tissue optics, these studies also lead to innovative instrumentation for life science research and clinical diagnosis of lesions. Current research efforts are focused on the development of a dual-image microfluidic flow cytometer that can be used to rapidly acquire 3D morphology features from biological cells and particles carried in a laminar flow. The 3D features, such as nucleus-to-cell volume and number of mitochondria, are extracted from a diffraction image with a CCD camera using pattern-recognition software. Another research project is to combine Monte Carlo modeling of tissue optics with a multispectral imaging technique to extract optical markers for staging and diagnosis of various skin lesions including melanoma. The goal is to develop a noninvasive optical biopsy technique.
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Graduate certificate in medical devices


The UNC-NCSU Joint Department of Biomedical Engineering offers a Graduate Certificate in Medical Devices for currently enrolled graduate students at Carolina and NC State. More information and the online entrance application may be found at the BME department's website through UNC or NC State.

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FDA issues “Approvable Letter” for ankle replacement system

Small Bone Innovations, Inc. specialists in the small bone & joint sector of the orthopedics industry, has received an 'Approvable Letter' from the U.S. FDA for its Scandinavian Total Ankle Replacement system (S.T.A.R. Ankle). The device is approved to proceed through the final steps of the PMA process as an alternative to fusion for replacing ankle joints deformed by rheumatoid arthritis, primary arthritis, or post-traumatic arthritis.

The implant is designed to mimic normal ankle movement and function. The tibial plate component, which attaches to the tibia, and the talar component, which attaches to the talus, are both made of a highly polished cobalt-chromium-molybdenum alloy. Both the upper tibial surface and the lower talar surface are coated with a titanium porous plasma spray coating to help enhance bone incorporation into the implant. The third component, the mobile bearing, is placed between the tibial and talar components and is made from ultra high molecular weight polyethylene. The S.T.A.R. Ankle is intended for uncemented use, allowing for better bone ingrowth and increased preservation of bone.
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Non-destructive imaging technology based on microscopy, ultrasound, holography

Semiconductor Research Corp. (SRC, Research Triangle Park, N.C.), a university-research consortium for semiconductors and related technologies, joined with Northwestern University (Evanston, Ill.) to demonstrate a unique ultrasound holography approach that enables scientists to view the tiniest of buried structures. Using a novel, non-destructive approach that combines scanning-probe microscopy with ultrasound and holography, researchers at Northwestern University have demonstrated the ability to view subsurface particles as small as 15-20 nanometers. A spin-off company, NanoSonix Inc., will develop a nanoscale-imaging toolset capable of rapid evaluation of defects and flaws below the surface as well as recognition of buried patterns and structures. The technology is expected to provide more effective treatments for medical patients.
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MPMD Database: What's New Spring 2009
ASM International brings to your desktop a comprehensive and authoritative set of mechanical, physical, biological response, and drug compatibility properties for materials and coatings used in medical implants. Click on What’s New for full details.

Update Highlights
Cardiovascular Module
In a major new extension to the database, information has been added for all FDA classifications of catheters and other related interventional devices.

Diagnostic Devices

• Catheter cannula
• Continuous flush catheter
• Electrode recording
• Guide wires
• Percutaneous catheter

• Embolectomy
• Septostomy

• Vascular clamps

• Fused silica
• Ni-Cr-Mo
• Polycarbonate
• Porcine small intestinal submucosa

• Poly(lactic acid)/hydroxyapatite (HAPLA)

• Alumina, zirconia toughened
• Bioactive glass
• Bovine cortical bone
• Calcium sulfate hemihydrate
• Fe-23Mn-21Cr-1Mo
• Poly(lactic acid)/tricalcium phosphate
• Poly(lactic-glycolic acid)/tricalcium phosphate
• Poly(lactide-co-trimethylenecarbonate)
• Poly(L-lactide-co-caprolactone)/tricalcium phosphate
• Polycarbonate
• Polyetherimide
• Polymethylpentene (TPX)
• Polyphenylsulfone
• Polysulfone
• Pyrolytic carbon
• Ti-3Al-2.5V

• Constrained Toe (General)