Robotic Knee Replacement

Q & A with Dr. Jeffrey T. Hodrick, MD regarding Robotic Knee Replacement. Dr. Hodrick is a Board Certified, fellowship-trained Orthopaedic Surgeon at the Southern Joint Replacement Institute in Nashville, TN.

What is Robotic Assisted Knee Replacement? Robotic knee replacement uses the latest, advanced software to optimize the planning and performance of knee replacement surgery. The components of the procedure include:

• Custom, enhanced 3D pre-operative planning in a virtual environment
• Ability to adjust the plan intra-operatively based on each patient's bone and soft tissue information
• Robotic assisted sawblade executes the planned bone cuts at an unmatched level of precision (.1mm cuts, and tenth of a degree of angulation!)
• Allows surgeon to focus on most important aspect of knee replacement, Balance!

Pre-Operative Planning The Mako robotic system uses CT scan information to make a custom 3-dimensional model of each patients bone. This includes precise measurements of the planned cuts of bone, the angulation of these cuts, and templated sizing and position of each of the implants. Since we are modeling each patients knee, this is truly a custom plan and preparation. I love to plan and no surgeon likes surprises. Having this information before the surgery allows me to know more about the patients anatomy so I can be more efficient and give the patient the best surgery possible!

Intraoperative Adjustment and Optimization I believe the most important thing I can do to ensure success after knee replacement is to "balance" the knee during the surgery. What this means is to have the same amount of tension in the ligaments on inside and outside of the knee when it is straight and when the knee is bent. If the tension is the same when the knee is straight and as it moves through a range of motion, the patient has a much better chance of feeling good. This is actually quite complicated. Performing robotic knee replacements allows me to marry the planned custom bone information from the CT scan with the soft tissue tension information I gather during the surgery. I am then able to adjust my virtual pre operative plan prior to making any bony cuts. 

Precision Performance of the Planned Surgery After making adjustments to the pre-operative plan and prior to cutting any bone, I am able to actually "see" the position of the implants on the bone in a virtual environment. This information is coupled with the measurements of the bone and implant relative to that patients specific anatomy. This ensures that I am respecting and accounting for each individuals anatomy. This is state of the art planning and understanding that has not been possible before.

The final stage of the procedure is when the robotic arm is used. We have planned each cut and have made our intraoperative adjustments. The saw blade that makes the cuts is on the end of the robotic arm. Importantly, the saw blade I use is thicker than typical saw blades. This eliminates the risk of the saw blade being deflected, cutting too much or too little bone . The saw blade and arm are controlled by a haptic boundary and plane. The easiest way to think of this is the haptic boundary as a force field. The saw blade will only travel in this planned plane. The saw will shut down if it is close to the boundary or if it gets close to cutting too much or too little bone. This not only executes the plan perfectly, but also adds a crucial safety element to the surgery protecting vital ligaments, bone, tendons, blood vessels, and nerves. The finished product, bone cuts, is a perfectly machined preparation of the bone in the exact planned position.

I feel confident that using robotics during knee replacement makes me a better surgeon and results in an easier recovery and better outcome for my patients. I am excited for the future of this technology as it continues to evolve and patients continue to experience these benefits. If you are suffering from knee, hip, or shoulder arthritis, or want to learn more about robotic technology, please call for an appointment with Dr. Hodrick at 615-813-4230 or visit us at www.nashvillehipandknee.com 

Author

Jeffrey T Hodrick, MD Dr. Hodrick is a board certified, fellowship trained, Orthopaedic Surgeon who practices at the Southern Joint Replacement Institute in Nashville TN. Dr. Hodrick is an international expert on robotic assisted joint replacement, direct anterior hip replacement, and enhanced recovery following joint replacement. His approach to patient care is to treat every patient as if they were a member of his own family.