A Medical Device Daily

A study presented at last week's annual meeting of the American Academy of Orthopaedic Surgeons (AAOS; Rosemont, Illinois) indicated that knee replacement surgery can improve the quality of life even for very elderly patients. The study found that patients in their 80s can benefit both physically and socially from total knee arthroplasty (TKA), once thought too risky for the very elderly.

"As patients are living longer, there is an upward trend in the demand for quality of life among the elderly population," said Edsel Arandia, MD, lead author of the study and an orthopedic surgeon at Philippine Orthopaedic Center and a fellow at Singapore General Hospital.

"As patients age," he said, "debilitating diseases like arthritis of the knee begin to develop. We conducted this study to determine the viability of TKA in octogenarians and to learn whether their quality of life improves after TKA."

Arandia and his team reviewed data from 128 patients older than 80 years of age who underwent knee replacement surgeries at Singapore General Hospital between October 1998-December 2006.

The results were measured using two quality-of-life scales, the SF-36 and the Oxford Knee Score, which assign scores to elements of physical and emotional health, such as physical pain, social functioning, vitality and physical functioning.

When the researchers compared the patients' preoperative scores to their postoperative scores up to two years following surgery, they found the quality of life scores had risen "significantly" during the postoperative period.

"In our institution, many surgeons are still skeptical to perform TKA in the very elderly, since few data or studies pertaining to the gains of TKA versus the complications and risks that can occur with surgery in elderly patients exist," Arandia said. "This study shows that with the advent of new technology and techniques in both orthopaedics and geriatric medicine, total knee arthroplasty in the very elderly population is very safe and offers significant gains in their quality of life."

Among other study findings presented at the AAOS meeting:

• Using a common mechanism to score activity levels after hip surgery, researchers found that the majority of patients who underwent a procedure to resurface arthritic hip bones consented to surgery with unrealistic expectations regarding outcome.

While many patients hoped to return to skiing, jogging, ballet or tennis after surgery, most instead continued to experience limits on activities due to pain and stiffness. They were, however, able to regain the ability to participate in low-impact activities that increased their quality of life. The researchers recommend pre-surgical counseling to set expectations.

• There is evidence that a patient who suffers a shoulder injury is likely to have a family history of such injuries. Family members, even distant relatives who have suffered tears to the rotator cuff, the muscles and tendons that hold the top of the upper arm bone in place, appear to create an increased risk for others on the same family tree to also develop a torn rotator cuff. This risk extends out to third-cousin relationships.

• Researchers found that if any relative, even distant, suffered a rotator cuff injury, there was a greater likelihood of suffering a rotator cuff injury before age 40.

• Patients who undergo hip replacement surgery often complain of stiffness and occasionally suffer severe muscle spasms, limiting surgical recovery and lowering post-surgical quality-of-life. When Botox is injected into spasming or stiff muscles around the hip, all of the trial patients showed increased hip range of motion, decreased pain, fewer (or zero) muscle spasms and were able to walk more normally with little or no limp.

Also at AAOS:

• Zimmer Holdings (Warsaw, Indiana) highlighted its exhibit space with an interactive Trabecular Metal Technology experience. The company also showcased several new product launches that span the company's portfolio, and the Zimmer Institute hosted presentations at an on-site education theater.

The Trabecular Metal Technology experience on the second floor of the massive Zimmer exhibit provided visitors with an interactive environment to explore the structure, function and physiology of what the company said is "the only tantalum-engineered porous implant material." Exclusive to Zimmer, Trabecular Metal Technology "replicates the structure of cancellous bone more closely than other implant materials and is conducive to more normal bone formation and bone in-growth," it said.

The product launches included:

— DeNovo NT Natural Tissue Graft for the treatment of focal cartilage defects in a variety of anatomic locations.

— The Zimmer Natural Nail system, which features anatomic-shaped implants designed to match the normal anatomy of long bones and achieve excellent fixation.

— The Zimmer Periarticular Elbow Locking Plate System, which offers anatomically contoured plates, optimized screw positions and options to address most fracture types.

— The new Trabecular Metal Glenoid, the only glenoid component with Zimmer's exclusive porous technology for biological fixation.

The Zimmer Institute hosted an on-site theater and "sawbones laboratory" sessions featuring presentations on a number of Zimmer products, including the Zimmer Gender Solutions Patello-Femoral Joint System, the M/L Taper Hip Stem with Kinectiv Technology; the NexGen LPS-Flex and LPS-Mobile Bearing Knee; and the Zimmer Natural Nail system.

• DePuy Orthopaedics (Warsaw, Indiana) launched two new high-flexion implants in the company's Sigma Knee System: the Sigma High Performance (HP) Partial Knee and the Sigma CR150 High-Flex Knee. The company also unveiled customized patient instrumentation, TruMatch Personalized Solutions, for knee replacement.

The company said the Sigma HP Partial Knee System is the only partial knee solution on the market that can replace the medial, lateral and patellofemoral compartments while providing low wear and up to 155 degrees of flexion. The tibial implants utilize a moderately cross-linked, oxidatively stable polyethylene.

The Sigma CR150 High-Flex Knee is the company's first high-flexion, cruciate-retaining knee replacement. DePuy said the Sigma CR150 System combines high function and conformity while accommodating up to 150 degrees of flexion. This implant includes oxidatively stable polyethylene and a highly polished cobalt chrome tray.

• Medartis (Kennett Square, Pennsylvania) introduced its nNew Aptus Adaptive Watershed Plating System.

The company said the new system has been made available in limited release and received "positive reviews" from surgeons who have used it.

• Merge Healthcare (Milwaukee), a medical imaging solutions provider, reported the release of Cedara ProPlanner 3.1, which it said was "built on years of work with orthopedic providers and vendors to offer a comprehensive digital solution for joint arthroscopy, trauma and deformity correction."

It said this newest release also gives health IT application vendors the ability to integrate these capabilities into existing applications such as PACS or EMRs.

Cedara ProPlanner contains features such as semi-automatic calibration, user-defined measurements and image stitching that help decrease the time and cost of planning for surgeons and vendors. A long-standing Merge Healthcare customer is preparing to launch this product in Asia to meet surgeon demand for increased workflow efficiency, accurate and detailed digital plans, and potential increased profitability.

• NDS Surgical Imaging (NDSsi; San Jose, California), a provider of medical visualization solutions for surgery suites, introduced new visualization tools that allow clinicians and surgeons in an operating room to view diagnostic images from radiology locations.

Radiology Imaging for the Surgical Environment or RISE, uses the company's Visualization and Informatics technologies to provide a solution that enables real-time, interactive consultation for medical professionals in the OR.

• RTI Biologics (Alachua, Florida), a processor of orthopedic, dental, surgical specialties and other biologic implants, launched two new biologic implants for use in sports medicine surgeries. Matrix HD, the first RTI dermis graft for sports medicine, and fresh-stored osteochondral (OC) talus allograft, an expansion of RTI's fresh OC line, are both now available through RTI's representatives and distributors.

Matrix HD heralds RTI's entry into the augmentation graft market and is the first crossover implant opportunity from the 2008 merger of RTI and Tutogen Medical. Matrix HD is acellular human dermis sterilized through Tutoplast, using the same processing technology that has been successful for membrane implants used in hernia, dental and other surgical specialties for more than 30 years.

RTI said it is expanding its fresh-stored OC line with the introduction of the fresh-stored OC talus allograft. The fresh-stored OC talus enables surgeons to resurface cartilage defects in the ankle with mature hyaline cartilage and healthy subchondral bone in a single procedure.