Knee Arthritis: Robotic-Assisted Total Knee Replacement Animation

Knee Arthritis: Robotic-Assisted Total Knee Replacement Animation

This animation demonstrates a robotic-assisted total knee replacement. Robotic-assisted knee replacement relies on software to build models, plan the surgical steps, and provide real time guidance throughout the procedure. The surgery follows 4 major steps. 1. Build a digital 3D model of the patient's anatomy. 2. Assess the patient's knee motion and stability. 3. Create the surgical plan. 4. Execute the surgical plan.

Here we see a patient lying face up on the operating table. The left leg is exposed with the knee bent. Step 1 begins with an incision along the front of the knee. The patella and other soft tissues are moved to the sides.

The robot uses a camera to detect sensors called arrays. Two pins are drilled into the tibia or shin bone, and the tibia array, labeled with a "T", is secured to the pins. Next, a pin guide is used to drill 2 pins into the femur or thigh bone. The guide is removed and the femur array, labeled with an "F", is secured to the pins. Here, the robot's camera registers where the F and T arrays are located in space, allowing the software to constantly track the location of the femur and tibia throughout the surgery.

Next, in a process called surface mapping, the surgeon uses a probe-tip sensor to map out the patient's anatomy. Starting with the femur, bony landmarks are probed first, and then the surface regions are traced and recorded into the software. The data gathered in the mapping process helps the software build a detailed model of the patient's knee anatomy, including the arthritic changes to the knee surfaces. This process is also completed on the tibia.

In step 2, a robotic device that measures knee stability is drilled to the tibia. This device has 2 paddles that are placed under the inner and outer portions of the femur. A constant force is applied to both portions of the femur as the knee is moved through the range of motion. The changes in tension help the surgeon determine the current knee stability.

Now that the software has recorded the 3D model and knee stability, the surgeon will move to the screen of the robot for step 3. Here, the robotic system helps the surgeon visualize positioning of the implants so that the surgeon can choose the correct size and alignment options for the patient. After making any adjustments, the surgeon finalizes the surgical plan and moves on to step 4.

The execution of the surgical plan starts with cutting the surfaces of both the femur and tibia. The surgeon attaches a robotic device that moves the cutting guide to the angle selected in the surgical plan. The surgeon makes the bone cuts after making the bone cut. The surgeon can use another array, labeled with a "V", to validate that the cut is aligned with the surgical plan. Each of the bone cuts are made and validated as needed.

Next, trial implants are inserted into the femur and tibia. The robotic device that measures knee stability is inserted again to assess how the implants corrected any imbalance. When the surgeon is satisfied with the placement, the final metal and plastic implants are inserted. The final positioning is confirmed for alignment and stability. All of the incisions will be closed and bandages will be applied. The procedure is complete.