Palm-Sized Surgical Navigation System Enabled by Analog Devices' MEMS Motion Sensing Technology

New KneeAlign® 2 System from OrthAlign uses ADI's motion sensor for better accuracy in knee replacement surgery.

NORWOOD, Mass.--(BUSINESS WIRE)-- Analog Devices, Inc. (NYSE: ADI) today announced that OrthAlign, Inc. has selected ADI's high-performance iMEMS® inertial motion sensing technology to enable its new portable surgical navigation system that guides femoral alignment during knee surgery. The KneeAlign® 2 System, which also provides precise tibial alignment, uses an ADI iSensor® digital IMU (inertial measurement unit) to allow an orthopedic surgeon to quickly determine the center of rotation of a patient's femur and calculate the precise angles to cut the bone in knee replacement surgery. Read the ADI/KneeAlign 2 case study.

The compact KneeAlign 2 System combines the alignment precision of large, computer-assisted surgical equipment with the simplicity of conventional instrumentation. The palm-sized KneeAlign unit and its associated cutting instrumentation are compatible with all implant systems used in TKA (total knee arthroplasty), a surgical procedure in which pieces of the knee are replaced with artificial parts.

"Successful TKA surgery depends on accurate knee alignment," said Patrick O'Doherty, vice president, Healthcare Group, Analog Devices. "By using an ADI iSensor IMU, the KneeAlign 2 provides alignment precision comparable to the larger, significantly more expensive camera-based navigation systems, which are shown to result in knee replacement alignment outcomes of 91 percent accuracy compared to 68 percent accuracy using conventional mechanical surgery. As the patient's knee is put through a full sweep of motion, the surgeon relies on the positioning and dynamics captured by the IMU to quickly determine the precise orientation of the femoral cutting block."
According to figures available from the Agency for Healthcare Research and Quality, approximately 675,000 Americans underwent knee replacement surgery in 2009. And it is estimated that this procedure will be performed on 3.5 million in 2030.* Currently, an estimated 30 percent of all TKA procedures result in poor implant alignment.**

"Analog Devices' iSensor IMU played an instrumental role in making the design of the KneeAlign 2 System possible," said Darius Kharabi, OrthAlign's vice president of Corporate Development. "This month we completed our limited use release of approximately 50 TKA surgeries using the KneeAlign 2 for both femoral and tibial navigation in highly regarded knee surgery centers across the United States, and the results are extremely encouraging. We plan to launch the KneeAlign 2 System in the first quarter of 2012, while continuing clinical studies at the Hospital for Special Surgery in New York, Scripps Green Hospital in California and other centers of excellence."

About the iSensor IMU Used in the KneeAlign 2 System

The ADI iSensor IMU designed into the KneeAlign 2 System supports the six degrees of freedom measurement realized from the merging of three accelerometers that provide linear motion and three gyroscopes capturing angular motion. The iSensor IMU is capable of precisely tracking an instrument's motion on all axes, even under severe operating conditions. The compact IMU device provides access to both calibrated and dynamically compensated sensor data over a standard digital SPI interface with the ability to digitally tune the sensor filtering and processing to adapt to multiple application scenarios.

Based in Aliso Viejo, California, OrthAlign is a privately held medical device company. OrthAlign provides orthopedic surgeons with user-friendly, cost-effective, surgical navigation products for precise alignment.
Making a Difference for Healthcare Customers

Analog Devices offers healthcare customers a comprehensive portfolio of linear, mixed-signal, MEMS and digital signal processing technologies for medical imaging, patient monitoring, medical instrumentation, and home healthcare. Backed by leading design tools, applications support, and systems expertise, ADI's products and technologies enable differentiation in healthcare designs - helping shape the future of diagnostics and monitoring equipment, as well as health and wellness devices. ADI's healthcare offerings can be found at

About Analog Devices

Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 60,000 customers, representing virtually all types of electronic equipment. A leading global manufacturer of high-performance integrated circuits used in analog and digital signal processing applications, Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices' common stock is listed on the New York Stock Exchange under the ticker "ADI" and is included in the S&P 500 Index.

* The Journal of Bone and Joint Surgery, "Projections of Primary Revision Hip and Knee Arthroplasty in the United States from 2005 to 2030," Steven Kurtz, PhD; Kevin Ong, PhD; Edmund Lau, MS; Fionna Mowat, PhD, and Michael Halpern, MPH, MD, PhD.

** The Journal of Arthroplasty, "Meta-Analysis of Alignment Outcomes in Computer-Assisted Total Knee Arthroplasty Surgery," J. Bohannon Mason, MD; Thomas K. Fehring, MD; Rhonda Estok, RN, BSN; Deirdre Banel, BA; and Kyle Fahrback, PhD, Vol. 22 N. 8 2007.

iMEMS and iSensor are registered trademarks of Analog Devices, Inc.
KneeAlign is a registered trademark of OrthAlign, Inc.

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Linda Kincaid, 781-937-1472

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