Computer-assisted knee surgery has been able to overcome the limitations of conventional knee replacement surgeries, addressing the issue of alignment using infrared cameras, images and advanced tracking devices to achieve precise alignment, says Dr Mandeep Singh, Senior Consultant, Orthopedics and Spine Care at VPS Rockland Hospital, New Delhi, while explaining the advantages of the navigational knee replacement technology.
Osteoarthritis is the most common form of arthritis that affects millions of patients in India. It causes pain, swelling, and reduced motion in joints. It can occur in any joint, but usually affects hands, knees, hip or spine. Osteoarthritis depletes the cartilage in joints. Cartilage is the slippery tissue that covers the ends of bones in a joint and act as shock absorbers. When this cushion between two joints called cartilage is lost, the bones rub together.
Over time, this rubbing can permanently damage the joint. One of the common treatments for extreme osteoarthritic patients is replacement of diseased joint. Joint replacement is most common in knee followed by hip. Knee replacement surgery has been around for over four decades and has been helping hundreds of thousands of patients with pain free mobility every year. As one would imagine, the procedure has evolved over the years and today’s technology makes this procedure much more effective and accurate compared to few years ago.
Traditional knee replacement has certain fundamental limitations. One of the most critical factors determining success of a knee replacement surgery is positioning of the implant/device. The surgeon must implant the device in such a manner that its components-a metal and plastic platform atop the tibia and a metal surface on the bottom of the femur-rub together, or “articulate,” at precise angles in order restore natural movement of the knee and to prevent premature or excessive wear of the implant.
As is commonly practiced, a surgeon achieves proper alignment through “feel.” That is, he uses specialized cutting blocks combined with his years of operating room experience to determine where best to remove bone for the implant. Any variation in implant positioning beyond acceptable range would mean misalignment of implant, resulting in increased wear of the replaced joint.
Studies show that nearly one-fifth of conventional surgeries result in poorly or misaligned joint.
But the good news is that the new age technology provides a solution to this limitation of traditional knee surgery. Computer-assisted knee surgery addresses this issue of alignment with an advanced convergence of multiple medical and software technologies. Using infrared cameras, images and advanced tracking devices, Stryker’s Nav III assisted knee replacement achieves precise alignment.
Nav III, the zero error technology, combines precision and accuracy of computer technology with the surgeon’s skill, delivering the best possible patient outcomes. It combines digital images of femur and tibia with an implant specific software package. The computer hardware can track the precise position of the patient knee and the surgeon’s instruments at all times during the procedure. It is like on-board computers in new age cars that provide driving directions using satellite navigation systems. Just like it provides a degree of precision, speed and accuracy not attainable with a map and compass, Nav III offers visual mapping of patient’s anatomy that help the surgeon make crucial decisions before and throughout the knee replacement operation. It combines the precision and accuracy of computer technology with the surgeon’s skill to give best possible outcomes.”
Nav III is the only navigation system with integrated active, wireless and bidirectional technology. Unlike other passive technologies, Nav III’s trackers, mounted on patient’s operating joint, constantly send out signals on its own an enable an active communication between the tracker and the camera. It gives real time images, information and data on patient anatomy leading to higher accuracy and reduced surgery time. Its unique wireless system significantly reduces infection rate and enhances patient safety.
As one would imagine, a surgeon armed with these tools has the potential to achieve better outcomes for the patient.
As computer-assisted procedure evolves, it will become less and less invasive. Nav III not only gives greater precision but also helps operate with fewer or smaller incisions. Conventional knee replacement surgery requires additional instrumentation to be inserted right through the thigh bone to determine the best possible angle for implant positioning. Use of navigation system eliminates the need for this major incision as the angle is determined by the integrated computer. This effectively means reduced blood loss and pain, faster recovery and reduced risk of any cardiac, neuro or respiratory complications due to fat embolism.