What patients undergoing robot-assisted knee arthroplasty surgery should know.

Over the last few years I have been facing an increasing number of demands from patients seeking for a second or third opinion before or after robot-assisted knee arthroplasty.

While some of them were curious about this new technology, others were compelled by the unusual if not to say aggressive promotion going along with this technology. Most sadly, some were clearly misled by their surgeon with lack of provided information on alternative nonoperative or surgical treatments, and on the benefits or even the disadvantages of the use of robot-assisted knee arthroplasty. The main driving forces behind the latter were probably not the surgeons’ scientific curiosity but possibly their dogmatic trust in the new technology, eventually supported by commercial considerations. 

• My own experience of robot-assisted knee arthroplasty
• The scientific reality

My own experience of robot-assisted knee arthroplasty

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Despite the use of a robot during the surgical interventions of several of these patients, I have seen a number of complications resulting from wrong surgical planning, wrong or premature indications for surgery and lack of surgical experience and proficiency.

The scientific reality

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Therefore, I wanted to summarize several important items for patients to consider before undergoing surgery with this new technology:

1. The patient always needs to question his or her surgeon if no alternative treatment option would be adequate to treat the disease. This does especially apply to patients under the age of 60 to whom a partial knee replacement has been proposed by their surgeon.
2. Currently, there is no scientific proof that robot-assisted knee arthroplasty surgery is any better than undergoing knee arthroplasty with an experienced knee surgeon without assistance of a robot.
3. Robot knee arthroplasty surgery is in its early investigation phase and high-quality multicenter research needs to be done in order to show if it is equally good as, or even superior to traditional surgery.
4. In experienced hands, traditional knee arthroplasty surgery without the use of a robot results in more than 98% of the operations demonstrating correct implant placement. On the opposite, robot-assisted surgery does not guarantee a 100% correct implant positioning either.
5. A robot does not replace the surgeon. If a knee surgeon is not familiar with the basic principles of knee arthroplasty, the use of a robot will not guarantee a correct implant placement.
6. Knee arthroplasty procedures always need thorough planning based on standard radiographs and long leg standing x-rays. In most of the cases additional imaging procedures like CT scans or MRI are not required if traditional knee arthroplasty will be performed.
7. Some types of currently available robots have several disadvantages like:
   • the need to get a preoperative CT scan to plan robot surgery adequately. This increases the amount of radiation to the patient in comparison to conventional x-rays.
   • a possibly longer operating time in comparison to conventional surgery.
   • Intraoperatively, 2 metal pins may need to be fixed in the femur and the tibia respectively to allow the robot to perform adequate bone cutting. This pin placement can weaken the bone and - although rarely reported - this may be a source of bone fracture.
   • If the knee of a patient is not well fixed to the operating table or if the patient moves for some reason during surgery, the robot may cause incorrect implant placement or in the worst case significant tissue damage.
   • Bone cutting by the robot creates heat which may be detrimental to underlying living bone structures. Long term studies will show if this will impact the longevity of the implants.
8. If patients’ large imaging and surgical data are used to plan and execute robot assisted surgery, patients should question whether data ownership and data management compliance will be respected.
9. While outpatient partial or total knee arthroplasty may be an option for a very limited group of patients, it is not the intraoperative use of the robot which is responsible for the shortening of the hospitalization time, but rather the type of pain control, the way the surgeon performs the procedure and the hospital organization.
10. There is no proof that robot-assisted knee arthroplasty decreases the already low complication rates of knee arthroplasty or shortens rehabilitation time.
11. Robot-assisted knee arthroplasty is less cost-effective than traditional knee arthroplasty because it generates more costs for planning, acquisition of the technology and time loss during surgery.

Finally, I would like to summarize that critical thinking, honest approaches to patients’ needs and desires as well as gathering of strong scientific evidence are necessary to implement new technology in the long term. Otherwise, robot-assisted knee arthroplasty risks disappearing in a similar way to previous fashions in knee arthroplasty surgery like computer-assisted surgery and the use of patient-specific instrumentation.

Luxembourg, December 2019