LONDON, Sept. 12, 2012 /PRNewswire/ -- Smith & Nephew (NYSE: SNN; LSE: SN), the global medical technology business, today announced the launch of its LEGION™ HK Hinge Knee implant to surgeons in the US and Canada. As the first hinged knee to be designed using normal knee kinematics, the implant provides a new option for those patients facing difficult primary or revision knee surgery. "This signals a real change in the hinge knee landscape," explains Gaurav Agarwal, DSVP and General Manager for Smith & Nephew's Advanced Surgical Devices division. "With this implant, we are not only simplifying the procedure, we are transforming these complex surgeries from salvage operations to true joint-rescue procedures." For patients, the LEGION HK Hinge Knee has been designed to closely match the knee's original anatomy while also restoring more normal function, thanks to next-generation rotating knee technology. In fact, the design of the implant provides a more natural range of motion[1,4] while maintaining an average of 96% condylar loading—a design feature shown to remove the stresses from the hinge link for lower wear on the hinge device. For surgeons, the LEGION HK Hinge Knee offers simplicity and familiarity. An extension of the clinically successful LEGION Total Knee System, the LEGION HK allows surgeons to seamlessly transition intraoperatively from a constrained revision implant to a hinged assembly, thus using a minimal number of instruments and the same simple, reproducible surgical technique they already know. "The LEGION HK system is a significant leap forward in treating complex knee revision surgery," says Dr. Kris Alden, Director of Joint Replacement at West Suburban Hospital in Chicago. "Its kinematic and bone sparing design not only alleviates my patients' symptoms, but also restores an almost natural knee function. Couple that with its ease of use, and it has greatly aided my practice when treating significant bone and ligamentous deficiencies." A hinged knee replacement is an implant system in which the three components (the upper, the lower and the plastic liner) of the implant are joined together with a hinged mechanism. Typically, this type of knee replacement is used when a knee is highly unstable and the patient's ligaments will not provide the support necessary for the more common type of knee implant.