Shape memory materials are considered “mechanically active smart materials.” They are defined by their ability to recover large deformations to their original shape on command in a controlled manner.
Medical devices using shape memory materials can be implanted through small incisions and be deployed to a larger size or different shape within the body to fixate tissues, repair fractures or restore normal anatomy.
The target market is a good size. Company officials note that nearly 1 million soft-tissue ACL procedures were performed in 2010, and that number is expected to grow steadily. The initial phase of the ExoShape launch last year featured sizes from 6-9 mm in diameter and 28-30 mm in length. In the middle of 2011, the sizes diameters of 10, 11 and 12 mm were added. The company received U.S. Food and Drug Administration 510(k) clearance early last year.
“We undertook a controlled market introduction of the ExoShape product to key sports medicine surgeons last year and received a tremendous amount of valuable feedback. We used this detailed information to further enhance the instrumentation and refine the surgical technique,” said Kurt Jacobus, president and CEO of Atlanta, Ga.-based MedShape. “We firmly believe that the ExoShape Soft Tissue Fastener will fulfill our promise to surgeons to deliver a unique, effective and easy-to-use tibial soft tissue fixation system.
According to Jacobus, ExoShape’sdesign supports reconstruction techniques as they continue to evolve to more accurately replicate the complex functionality of a patient’s natural ACL. The system uses a non-rotational deployment technique that preserves the surgeon’s desired graft bundle orientation and tension during single tunnel-double bundle procedures.
When used with soft-tissue grafts, traditional interference screws exhibit low ultimate yield loads and can damage the graft during insertion. In an attempt to overcome these issues, surgeons have turned to “sheath-and-screw” devices that offer improved graft fixation and graft protection. However, these solutions may continue to compromise graft bundle orientation due to the sheath rotating within the tibial tunnel, as significant manual torque is required to drive the screw into the sheath and achieve adequate interference fixation of the graft, according to the company. The need to drive screws into these devices in a direction counter to the desired direction of graft tension also may introduce undesirable laxity into the graft construct. The ExoShape Soft Tissue Fastener attempts to address these issues.
MedShape is a privately held medical device company working to develop a portfolio of surgical solutions based on its patented shape memory technologies in the areas of sports medicine, joint fusion and musculoskeletal trauma products.
Medtronic Rolls Out New Spine Instrument Technology
The spine division of medical device giant Medtronic Inc. recently unveiled new implant and instrument technology.
Included in its new offering was the firm’s new MAST MIDLF procedure, which uses a proprietary retractorand cortical bone screw fixation in conjunction with the company’s interbody, navigation, neuromonitoring and biologic technology options. Referred to clinically as a midline laminectomy approach, Medtronic officials say it is unique because enables a minimally invasive spinal fusion surgery, accessing the spine in the middle lower back, and eliminates the need for surgeons to work through atubular retractor.
“This surgical strategy enables a highly efficient, minimally invasive lumbar fusion, while allowing visualization of familiar posterior landmarks,” according to Richard Hynes, M.D., spine surgeon at The B.A.C.K. Center in Melbourne, Fla. “A midline approach offers surgeons a number of benefits in addressing the challenges associated with decompression as well as sacral fixation in the lumbar or lower spine.”
The MAST MIDLF procedure also can be used with Medtronic’s surgical navigation and imaging systems. This allows for decreased exposure to radiation for hospital staff and physicians, with improved accuracy of device placement to avoid injury to nerves.
In the United States, more than 250,000 patients undergo spinal fusions annually to treat degenerative changes in the lumbar spine, according to the North American Spine Society.
Minimally invasive surgery (MIS) requires a smaller incision than traditional open-back surgery and reduces injury to muscles, tendons, and other normal tissues that aren’t directly involved with back disorders. In addition, MIS surgery often leads to shorter hospital stays than traditional open spine surgeries.
Medtronic also launched the T2 Altitude Expandable Corpectomy device in the United States and Europe. The product is a self-locking expandable vertebral body replacement cage intended for use in the thoracolumbar spine (T1-L5). It is designed to provide spinal stabilization and correction in patients suffering from a trauma or cancerous tumors.
According to the company, the device features an innovative self-locking mechanism that eliminates the need for placing a set screw during surgery. This device can be filled with bone graft after insertion and also after expansion, creating bone contact with the end plate and the opportunity for fusion to occur inside the device. Possible risks include early or late loosening of the components and implant migration, and the disassembly, bending, and/or breakage of any or all of the components.
T2 Altitude comes in multiple sizes, allowing a surgeon to fit the various needs of a trauma or tumor patient.
Additionally, the device gives surgeons options to insert the cage from a posterior, anterior or lateral approach and is compatible with Medtronic’s proprietary minimally invasive MAST technologies.
This system also is compatible with Medtronic’s neuromonitoring system, the NIM-Eclipse System. The device is to be used with supplemental fixation such as Medtronic’s Vantage Anterior Fixation System, TSRH Spinal System, or the CD Horizon Spinal System.
Each year, there are more than 150,000 spinal fractures in North America. There is an estimated 10,000 to 12,000 spinal cord injuries every year and approximately 39 percent of these injuries are caused by motor vehicleaccidents. Non-elective or trauma surgeries oftenrequire additional spinal structural support, which is when the T2 Altitude is used.
Another indication for use is in the treatment of cancer patients. If the cancer metastasizes or spreads in the spine, the surgeon may remove the affected vertebral bodies and replace them with the T2 Altitude.
The system is equipped with animplant tracking system to enhancehospital efficiencies, support hospital-specific quality management and provide device utilization-related data to meet anticipated U.S. Food and Drug Administration regulations establishing a unique device identification system.
“We continue to deliver on our long-term commitment to therapies for complex spine disorders for spinal tumor, trauma and deformity patients,” said Doug King, senior vice president and president of Medtronic Spinal. “T2 Altitude is a new option for surgeons who perform corpectomies, including through the use of minimally invasive techniques.”
Medtronic’s spinal business is based in Memphis, Tenn.
Study Touts Benefits of Patient-Matched Tech
Smith & Nephew plc has always touted its Visionaire knee replacement system, claiming the product’s patient-matching technology provides consumers with custom-fit implants that rival their old joints.
Now, finally, the company has proof to support its rhetoric. A study published in The Journal of Arthroplasty concluded that surgeries using patient-matched instruments (such as those included in Smith & Nephew’s Visionaire system) produced implants that were a full degree closer to neutral—the body’s natural alignment—than those which used traditional instruments. The accurate placement of an implant long has been considered and shown to reduce implant wear andimprove longevity, according to Smith & Nephew executives.
“Patient-matched technology is driving a shift in thinking for our entire industry,” Scott Elliott, senior vice president of Smith & Nephew’s Global Knee Franchise, said in a news release. “This study shows that Visionaire patient-matched technology improves outcomes forpatients, simplifies the operating room experience for surgeons and pulls cost out of the healthcare system.”
Surgeons using the Visionaire system scan magnetic resonance and X-rayimages of the patient’s knee into anadvanced Web-based software program, which generates virtual images of the affected joint. Smith & Nephew thendesigns and builds surgical instruments and guides (including specific bone cuts) to align the company’s Journey or Legion implants to the patient’s knee.
In addition to improving alignment, the Journal study concluded that patient-matched implant technology:
• Reduces the amount of time apatient spends under anesthesia;
• Shortens hospital stays; and
• Reduces the length of the surgicalincision required for knee replacements.
Other benefits of patient-matched technology, according to Smith & Nephew, include minimizing blood loss and cutting the risk of infection after surgery.
The company also claims that itsVisionaire system can help reduce hospital expenses because it eliminates more than 20 surgical steps for each procedure and reduces the number of required instrument trays by 43 percent. Those savings, company executives contend, can help reduce sterilization costs and improve operating room efficiency.