More than 4.7 million Americans are currently living with a prosthetic knee. The incidence of total knee replacement (TKR) increased by 120 percent from 2000 to 2009: 188 percent for patients ages 45 to 64, and 89 percent for patients ages 65 to 84. As a result of the growing popularity of TKR, technical advances are of great interest.
Until recently, TKR has been a major ordeal for patients. The orthopedic surgeon would navigate into the joint by eye and use relatively crude mechanical instruments to shape the bone to fit the prosthesis. Patients could expect to spend as long as three to five days in the hospital and take as long as three to six months for a full recovery.
Such long recovery times are now a thing of the past—thanks to a brand new computerized technology that allows visualization of the joint in 3-D before the first bone cuts are made. For the first time ever, it is now possible to see precisely where to cut beforehand, ensuring the surgery goes as smoothly as possible. Also, due to the increased accuracy of the surgery, patients can get out of the hospital and recover much more quickly.
This advance is made possible by the APEX Robotic Technology™ (ART) Surgical Navigation System, developed by OMNIlife science, Inc. of East Taunton, MA. The system is designed for TKR and provides computer-guided precision. To date, more than 3,000 TKR procedures in the United States have been successfully completed using OMNI’s surgical navigation system.
The system’s BONE MORPHING® technology allows the construction of a patient-specific 3-D model of the knee in real time to create a virtual surgical plan prior to critical bone cuts. Navigation algorithms and adjustable resection guides enable the reconstruction of the mechanical axis of a limb. No preoperative CT or MRI is required.
This is complemented by the iBlock® Cutting Guide, an intelligent robotic guide that automatically positions instruments allowing femoral resections that optimize implant alignment. ART instrumentation allows for simple, micrometric adjustment intra-operatively to ensure alignment and balance of the knee joint. Real-time assessment of limb alignment and soft tissue can be made at any time during the procedure.
Initially the patient is positioned and anesthesia administered. Reference markers are pinned onto the tibia and femur that will be tracked by the computer in a 3-D space. Specific locations of the exposed knee joint can then be measured. When this is done, a detailed, accurate 3-D model of the knee joint and alignment of the leg is created.
The computer determines the size and position of each implant component. The end of the femur is reshaped using a saw, through a cutting guide that is aligned robotically. Subsequently, the tibia is also reshaped. Following preparation, the components are inserted into the knee, ensuring the joint is working properly, and the reference markers are removed. Following the procedure, the incision is closed and bandaged.
Most robotic technologies being used today for knee resurfacing procedures are only offered for unicompartmental or partial knee replacement. OMNI’s ART system is specifically designed for TKR, providing the precision of a robot on even the most significant knee joint deformities. This has uniquely positioned OMNI as a leader in robotic TKR.
ART is designed to work in tandem with OMNI’s APEX Knee Reconstruction System, which was designed to provide a concise and logical set of options to accurately restore joint mechanics, improve stability and maximize range of motion of the knee. Designed from the ground up, the system is based on extensive clinical anthropomorphic analysis of male and female anatomy. As a result, the APEX knee is offered in a wide range of primary sizes as well as specifically designed and proportioned intermediate sizes with design characteristics that allow surgeons to specifically match unique anatomic requirements for both male and female patients.
Together with the APEX Knee Reconstruction System, the ART Surgical Navigation System offers a new option for surgeons and TKR patients alike.
George B. Cipolletti is President & CEO of OMNIlife science, Inc., a medical technology company targeting the rapidly growing global hip and knee replacement medical device sector.