Medical Device Daily

PARIS – Prosthetics are advancing by leaps and bounds this summer.

Later this month, a giant step for people with disabilities will be taken when double amputee Oscar Pistorius competes for the first time with fellow South African sprinters in the 400-meter relay at the International Association of Athletics Federation (IAAF) World Championships in Daegu, Korea.

The IAAF ban on athletes using “any technical device“ was overturned clearing the way for Pistorius to become the first amputee to run on prosthetic “blades“ against able-bodied athletes.

Then in July he turned in a personal best time of 45.07 seconds for 400 meters, qualifying him for a spot on the South African national team.

He now has his sights set on the 2012 Olympics to be held in London, rather than the follow-on Para Olympics where he has become a legend and an icon for people with disabilities.

On the heels of this break-through a long-time sponsor of the Para Olympic Games, Otto Bock, announced the release of its next-generation C-Leg, a microprocessor-controlled leg prosthesis that intelligently adapts to an amputee's individual gait.

It has been 15 years since the original C-Leg was introduced and the long-awaited upgrade includes advanced software for controlling the 'swing phase' of the device, enhancements to performance with new motors and valves for the hydraulic system and an increase in battery life.

A significant new feature is defined modes of operation for walking, bicycling or standing still for long periods.

“Walking has been described as a controlled fall, and an above the knee amputee works hard at not falling all the time,“ said Phillip Yates, Managing Director of Otto bock Healthcare (Egham, United Kingdom).

“When you are crossing the road in a crowd of people, stopping suddenly or moving forward too quickly can result in an unfortunate incident not only for yourself but involving other people as well,“ he said.

The goal of the microprocessor-assisted movement is to closely match natural human movement, mimicking the human skeletal system for balance and walking.

“The microprocessor knee unit actually knows where it is in the swing phase, whether you are coming off your heel of going onto your toe,“ said Yates.

“It measures where it is in space 50 times per second, it knows where you are in the cycle and how quickly you are walking, so that if any misadventure should occur, such as catching your heel or your toe, the unit will lock up to prevent you from stumbling and possibly falling,“ he said.

The C-Leg has been shown in consecutive clinical studies to reduce the incidence of falls by 64% when compared to mechanical knees.

Studies have also shown that by significantly enhancing the ability to walk, the C-Leg enables amputees to approach the behavioral pace and performance of able-bodied persons.

An overwhelming 90% of study participants reported improvement in function but also a meaningful transformation in the character of their everyday surroundings and a reduced sense of deficiency and displacement in relation to others.

The benefits of the C-Leg need to be compelling as the price tag for the prosthesis and fittings running to £30,000 ($50,000), more in the range of an automobile than a medical device.

It is a fair comparison, agrees Yates, adding, “These are two different levels of mobility, and to get back independence, amputees see there is a benefit.“

He said more than 40,000 C-Legs have been sold, and that six next-generation C-Legs had been sold prior to the product launch.

“It opens a new dimension for active amputees who are getting back to work or taking up activities of a normal life,“ he said.

Approved for reimbursement in most countries, the largest customer segment remains those who are able to pay for the device out-of-pocket.

For example, the C-Leg is approved for the United Kingdom's National Health Services Framework Agreement, though it is marked as restricted as it is cost-prohibitive for most patients.

The C-Leg, however, is widely prescribed by the United States military, Yates said, to help soldier rehabilitate themselves to a normal life and possibly for a return to active duty.

Otto Bock invests €37 million ($53.5 million) of its €528 million ($763 million) in annual sales revenue to research and development.

A sneak preview of upcoming products during the International Society for Prosthetics and Orthotics (ISPO) World Congress in Leipzig in 2010 included the Genium Prosthetic Knee System, a new platform that re-engineers the C-Leg technology.

“Genium takes a completely different approach resulting in additional functionality, such as the ability to walk up stairs, which the C-Leg can not do,“ said Yates.

At ISPO in Leipzig, Otto Bock also demonstrated a work-in-progress, the Michelangelo Hand.

Medtronic gets CE mark for 31 mm CoreValve

Medtronic (Minneapolis) said it has received the CE mark for its 31 mm Medtronic CoreValve system, the only transcatheter aortic valve available in the world that can treat– without surgery – patients with larger valve openings (up to 29 mm). It is the largest transcatheter valve available and, because it can be compressed into a small delivery system, is deployed through the same 18Fr (less than ¼-inch or approximately 6 mm in diameter) delivery system as smaller CoreValve sizes.

Medtronic's CoreValve portfolio now includes 26 mm, 29 mm and 31 mm valves – all based on the self-expanding platform that received CE mark in 2007. Individual sizing is critical to achieving optimal patient blood flow (hemodynamic function) and reducing adverse events, making the availability of an additional size an important offering to physicians and patients. The system is currently limited to investigational use in the U.S.

The CoreValve system is designed to provide a minimally invasive treatment option – without open-heart surgery – for patients with symptomatic, severe aortic stenosis who are at high risk, or are ineligible, for open-heart surgery. Worldwide, about 300,000 people have been diagnosed with this condition, and approximately one-third of these patients are deemed at too high a risk for open-heart surgery. Since 2007, the system has been implanted in more than 15,000 people in more than 40 countries.