Robotic knee surgery uses advanced technology, typically involving a robotic arm or guidance system, to assist the surgeon during a total knee replacement (TKR) procedure. This assistance is designed to enhance the precision of bone cuts and implant placement based on a detailed pre-operative plan. While the technology offers potential benefits in surgical accuracy, it also introduces several distinct disadvantages that patients and healthcare systems must consider.
Increased Procedure Costs and Limited Availability
The adoption of robotic-assisted knee surgery is hampered by the high capital investment required for hospitals to acquire the necessary equipment. These advanced robotic systems can cost anywhere from $500,000 to over $1 million per platform, which does not include the additional expenses for annual maintenance and specialized disposable instruments. These substantial costs are often passed on to the patient or payer, making the procedure significantly more expensive than a traditional manual TKR. One analysis found that the total direct cost per case for robotic TKA was approximately $3,000 greater than for the manual procedure.
The higher cost means the technology is often concentrated in high-volume, specialized centers, typically in urban areas. This limited distribution creates a distinct access barrier for patients living in rural or economically disadvantaged communities. For a hospital to make the robotic system cost-effective, it generally needs to perform a minimum number of cases annually, with some models suggesting at least 50 cases per year.
Extended Operating Room Time and Setup Complexity
Robotic knee surgery often requires a longer duration in the operating room compared to a conventional procedure. While the actual bone-cutting phase may be precise, the overall operative time is extended by the required steps for system preparation. This includes draping the complex robotic machinery, positioning the patient and the robot, and then “docking” and calibrating the system to the patient’s anatomy.
A longer total operating room time means the patient spends more time under anesthesia, which can elevate the risk of anesthetic-related complications. Studies have shown that the operating time for robotic TKA can be significantly longer, with one comparison showing an average of 139 minutes for robotic surgery versus 107 minutes for the manual approach. The initial learning curve for the surgical team can further contribute to these extended times until proficiency is achieved.
Unique Pre-operative Imaging Requirements
Many robotic-assisted knee surgery platforms require a specific pre-operative Computed Tomography (CT) scan to generate the precise three-dimensional (3D) model of the patient’s joint. This detailed 3D map is necessary for the computer-guided navigation system to accurately plan and execute the bone cuts. The requirement for a CT scan is a disadvantage because it is not a standard component of planning for manual TKR.
The need for a CT scan introduces additional logistical steps and time for the patient before the scheduled surgery. More importantly, it exposes the patient to an extra dose of ionizing radiation. The mean effective radiation dose from a pre-operative CT scan for robotic planning has been calculated to be approximately 4.8 mSv, which is a significant increase compared to the minimal dose from standard X-rays used in manual TKR planning.
Specific Hardware and Mechanical Risks
The robotic approach introduces specific risks related to the hardware required for the system’s function. To track the position of the patient’s leg in real-time, temporary metal pins are drilled into the femur and tibia to secure optical tracking arrays. Although generally rare, the placement of these pins can lead to complications such as superficial pin-site infection, pin loosening, or stress fractures at the pin sites. The overall rate of pin-related complications in robotic knee arthroplasty ranges between 0.3% and 1.9%.
The most commonly reported pin-related issues include superficial infections and pin dislodgement. Furthermore, there is a low but distinct risk of periprosthetic fracture occurring at the pin site, either during the operation or in the post-operative period. Finally, a technical malfunction of the complex robotic system can occur during the procedure, which would necessitate an immediate conversion to a traditional manual surgical technique.