Does Dr. Cumbie perform robotic knee replacement?

Yes. Dr. Cumbie uses the Stryker MAKO Robot and is certified to use the Zimmer ROSA Robot. Each robot offers different advantages for different situations.

Dr. Cumbie often uses robotic assistance as part of his Pure Motion knee replacement technique. This approach aims to position the implants to closely match each patient’s unique anatomy, recreating the joint line, axis of rotation, and limb alignment as they were before arthritis. The goal is to restore knee motion that feels as natural as possible.

What is robotic-assisted knee replacement?

Many patients ask for a “robotic knee.” This means the surgeon uses a robotic tool to help place the implants more accurately. However, the robot does not guarantee a perfect result and does not tell or guide a surgeon with regards to the best implant position for each patient. The surgeon is always in control and decides exactly where to place the implants.

For example: If 100 surgeons planned a robotic knee for the same patient, each surgeon might choose a slightly different position for the implants. That’s why it’s important to have a skilled surgeon who understands your anatomy and has a clear, evidence-based philosophy and training for positioning the implants to ensure the best chance for a successful outcome.

How is a robotic knee replacement performed?

• The surgeon first plans how to position the implants, using the robot’s software.
• The robot then helps guide the bone cuts needed before placing the new knee parts.
• The bone cuts will determine how the final implants are positioned.
• The final position of the implants determines how your knee moves after surgery.

Traditional vs. Pure Motion Knee Replacement

Traditional knee replacement surgery often relies on a standardized approach, positioning the knee implant in the same way for every patient. This technique typically aims to recreate a mechanically neutral alignment, cutting the tibia for every patient at a neutral 0 degrees, regardless of their individual anatomy or how their knee naturally moved before arthritis. However, research—including the CPAK classification—shows that most people do not naturally live in this alignment, and forcing every knee into a single mold can disrupt the natural synergy of your knee’s supporting structures.

In contrast, Dr. Cumbie’s Pure Motion philosophy is to restore the elegant balance among your muscles, tendons, and ligaments, allowing them to function in a way that reflects your unique anatomy and natural joint motion. By recreating your native joint line and axis of rotation, Pure Motion knee replacement helps your knee move in a way that more closely resembles how it functioned before arthritis. To achieve this level of precision, Dr. Cumbie frequently uses advanced robotic technology, which acts as an extension of his expertise—helping tailor each knee replacement to each patient’s unique anatomy and natural joint motion.

What does the research show?

Recent high-level studies, including randomized controlled trials and meta-analyses, have shown that restoring the native joint line and limb alignment—like Dr. Cumbie does in a Pure Motion knee replacement—can lead to better knee function, greater range of motion, and higher patient satisfaction. This approach is supported by research using the CPAK classification, which demonstrates that matching the knee’s original anatomy allows the muscles, tendons, and ligaments to work together more naturally after surgery.

In contrast, the traditional approach to knee replacement positions the implants in a standardized way for all patients, regardless of their individual anatomy. Studies have found that patients whose implants are positioned to restore their original knee anatomy experience more natural knee motion, improved functional scores, and walk further before discharge, without an increase in complications. Long-term research also shows that restoring the native joint line and limb alignment provides at least equivalent, and sometimes better, patient-reported outcomes compared to the traditional standardized method. The CPAK classification framework and other peer-reviewed research support this patient-specific approach as a way to improve comfort, function, and satisfaction after surgery.

References:

• Liu B, Feng C, Tu C. "Kinematic alignment versus mechanical alignment in primary total knee arthroplasty: an updated meta-analysis of randomized controlled trials." Journal of Orthopaedic Surgery and Research. 2022. Read here
• Dossett HG, et al. "A Randomized Controlled Trial of Kinematically and Mechanically Aligned Total Knee Arthroplasties: Long-Term Follow-Up." The Journal of Arthroplasty. 2023. Read here
• Pangaud C, et al. "Restoring the Preoperative Phenotype According to the Coronal Plane Alignment of the Knee Classification After Total Knee Arthroplasty Leads to Better Functional Results." The Journal of Arthroplasty. 2024. Read here

Why does this matter?

Before arthritis, your knee moved comfortably and naturally. Arthritis and cartilage loss changed how your knee works—like how worn tires affect a car’s ride. You wouldn’t want new tires put on at the wrong angle; the same logic applies to knee replacement. Dr. Cumbie’s goal is to restore your knee’s natural movement by matching the implants to your original anatomy.

To learn more about Pure Motion Total Knee Replacement with robotic assistance, call to book an appointment with Dr. W. Gaines Cumbie or join his free virtual webinar.