Technology Drives Patient Care

AAOS annual meeting provides forum for industry and physicians to discuss the promise of orthopedics.

Christopher Delporte

Group Editor

The 2007 Annual Meeting of the American Academy of Orthopaedic Surgeons held its 74th annual meeting in San Diego, CA, from Feb. 14-18. The event attracted a total of 28,518 attendees, including 11,988 physicians and 13,295 technical exhibitors, according to AAOS officials. It was the first time the meeting was held in San Diego.

In addition, there were 450 technical exhibits, 20 symposia and 1,260 papers, posters and instructional course offerings.

During the academy’s proceedings, James H. Beaty, MD was elected the 75th president of AAOS, replacing Richard F. Kyle. Beaty currently is chief of staff at the Campbell Clinic in Memphis, TN. He’s a pediatric orthopedic surgeon and professor of orthopedics and pediatric trauma.

“The academy is an exciting group of people and ideas. I see it as a leader among medical professional organizations,” said Beaty. “It is my privilege to lead and grow with the AAOS.”

Beaty said his top priorities while at the helm of the AAOS are to continue high-quality education and research programs; serve as a leader and role model with respect to trauma on-call issues; and to find ways to introduce new technology to patients and members. Much of the new technology Beaty is preparing to champion was being discussed in conference sessions and featured on the exhibit floor.
Image-Guided Technology & MIS

One example of the new breakthroughs Beaty mentioned is image-guided technology that allows orthopedic surgeons to align implants with near pinpoint accuracy. For patients undergoing total knee arthroplasty, for example, close to perfect alignment translates into longer durability of joint replacements, according to a panel of surgeons who discussed advancements in computer-assisted total knee replacement (TKR) surgery.

Approximately 300,000 knee replacement surgeries are performed each year in the United States. Standard knee replacements require the use of an intramedullary (IM) rod, which is inserted up the length of the femur to determine proper knee implant alignment. No IM rod is necessary for the computer-assisted approach, reducing the risk of fat embolization, a complication that can cause acute respiratory distress. The quality and accuracy of the image guidance may enable surgeons to use smaller incisions while achieving the same successful outcomes, experts said.

“Computer assisted total knee arthroplasty surgery is making rapid progress,” said Dr. Daniel J. Berry, professor and chairman of Orthopedics at the Mayo Clinic in Rochester, MN. “Contemporary methods of computer-assisted surgery now have been proven to provide a high level of accuracy in experienced hands. Current efforts are focused on making the process simpler, more efficient and more cost effective. As these methods evolve, it seems likely some form of computer assistance will eventually become a routine part of total knee arthroplasty.”

At present, computer-assisted TKR involves extra time and additional difficulty because it still is in its infancy, according to panel experts.

During the meeting, San Diego-based PLUS Orthopedics USA announced that is had received FDA 510(k) clearance for the next generation of its PiGalileo computer-assisted surgery system for knee replacement procedures, including minimally invasive surgery and ligament balancing options. According to PLUS, two of the most common causes of joint implant failure are implant misalignment and ligament instability, with a misalignment of only three degrees being strongly correlated to excessive wear and tear on the joint and implant failure over time.

Minimally invasive surgery (MIS) also continues to be a major theme in orthopedics. For example, in the last 10 years, huge gains have been made in using MIS for hip replacements. Patients who qualify for MIS no longer have to endure the pain from traditional procedures, in which surgeons had to make large incisions, up to six inches long.

According to surgeons discussing the topic during the meeting, MIS can offer fewer complications and patients can recover much faster with only one small surgical scar, about two inches in length. In 2003, approximately 217,000 total hip replacements were done.

However, doctors trained in the procedure estimate that only 17% to 20% of their patients are candidates for MIS. A study done by the Mayo Clinic indicated that MIS is not free of complications. MIS takes more time than the conventional surgery, requiring more anesthesia, and it can cause more muscle damage than the traditional “open” surgery. Surgeons also expressed concern about the number of surgical revisions following MIS procedures. Current obesity trends also make MIS procedures more difficult. In addition, surgeons cited long-term durability of the hip replacement as being more important than the length of the patient’s hospital stay.

Technology in Focus

Warsaw, IN-based Zimmer highlighted the company’s Gender Solutions Technology. During the AAOS meeting in Chicago last year, Zimmer introduced the first knee implant designed specifically to fit the female anatomy; the product was cleared for sale in the United States by the FDA in May 2006. Nearly 10,000 Gender Solutions knees were implanted in the fourth quarter of 2006, the company said. Elliot expects an additional 12,000 to be implanted in the first quarter of 2007.  

At this year’s AAOS meeting, Zimmer took gender-specific products a step farther with new developments in gender-specific hips, including a hip stem with a new head-neck assembly design called Kinectiv technology, and the application of more flexible PEEK-based EPOCH hip technology.

At Smith & Nephew’s booth, one of the main attractions was major league baseball pitcher Randy Johnson. A former pitcher for the New York Yankees who was traded this season to the Arizona Diamondbacks, Johnson reached an agreement with Smith & Nephew to promote the firm’s Supartz joint therapy product. Supartz is an injectable liquid used to treat osteoarthritis of the knee.

New for 2007, the company rolled out its Journey Deuce knee, which Smith & Nephew says is a first of its kind. The Deuce is a bi-compartmental knee that allows physicians to treat the medial compartment and the patella-femoral joint, preserving both cruciate ligaments. Much like the solution offered with hip resurfacing, more of the natural knee is preserved. The knee is implanted using a minimally invasive surgical approach due to incision size, but also because less natural tissue is removed.

DePuy Orthopaedics in Warsaw, IN used the meeting to announce two new options for restoring hip mobil-ity in patients who require total hip replacement. The Pinnacle Acetabluar Cup System Ultamet XL and the Pinnacle Acetabular Cup System AltrXTM hip bearings are designed to recreate the natural ball and socket joint of the hip to help increase joint stability, range of motion and longevity, the company said. DePuy also unveiled its Agility LP Total Ankle Replacement for the treatment of end-stage ankle disorders. The Agility LP Total Ankle is intended to provide an alternative to ankle fusion surgery as well as advancement in current ankle replacement technology, according to DePuy.

New York, NY-based Small Bone Innovations debuted its new Lateral rHead modular elbow implant. The device, which received 510(k) clearance from the FDA in December, is comprised of a uniquely designed mechanical couple between the head and stem components. The device provides surgeons with yet another option for treating radial head fractures and disease.

The 2008 AAOS annual meeting will be held March 5-9 in San Francisco, CA.