Surgical Robots for Knee Surgery
During the surgery, the intervention is supervised on a monitor. ©Schloss Werneck

At Sankt Marien Hospital Buer, knee replacement is performed with the help of a robot. The system facilitates the surgeon’s work, but does the patient also profit from it?

For Alexander Awakowicz, the 23rd July 2020 is a special day. He just operated on a patient with the help of a surgical robot for knee surgery for the first time. Everything worked out exactly the way he wanted it to. “I am satisfied with the results”, says Awakowicz, who works as a chief physician for orthopedics at Sank Marien Hospital Buer in Gelsenkirchen. However, the surgical robot’s medical added value has only been proven in short-term studies.

The new robot is called Balance Bot and is produced by the British Corin Group. Awakowicz is the first one to try it in Germany. With a purchase price of around 350,000 euros, it is one of the smaller surgical robots.

The orthopedic department of Schloss Werneck near Würzburg has two robotic systems which each cost one million euros. Clinic director Christian Hendrich was the first person in Germany who purchased a surgical robot called Mako from Stryker shortly before Christmas 2013. He is totally convinced by the technology: “I would let myself and my mum be operated with the help of the robotic arm.” He just ordered two more robotic systems which will be delivered in September.

Three main advantages of the surgical robot

The history of orthopedic robotics is already a few decades old. Since the occurrence of the first orthopedic robotic system Caspar, there are three main advantages the new system should give: to facilitate the work of the surgeon, to improve the treatment of the patient and to increase the revenue of the clinic.

The first aspect can be ensured by the robotic system, the surgery gets easier for the surgeon. Before surgery, a CT scan of the knee is made for further planning. During the operation itself, the surgeon’s hand is led by the robot. “Without the robot, the accuracy is at 3 degrees, with the help of the simulation it is at only ½ degree”, says Hendrich.

Awakowicz noticed another advantage during his first surgery on a real patient: the tendon tension is measured. If the leg cannot be moved optimally, the prosthesis can be fitted. After the surgery, some patients complain about pain when walking because the prosthesis doesn’t fit properly. “For knee prosthesis, there are 20% dissatisfied patients only due to the imbalance of the joint. Studies have shown that we can decrease this value to five percent with the robot”, says Awakowicz.

Short-time studies prove effectiveness

At present, there is no German study on the effectiveness of robot-assisted knee surgery. However, there are various works from the Anglo-Saxon area. Cesar Ituriaga and Hytham Salem from Lenox Hill Hospital in New York recently summarized available studies in June. Their conclusion after evaluating eight publications: It’s true! Using robots for knee surgery improves the provision of patients, the prostheses fit more accurately, the patients stay at the hospital for a shorter time and have less pain.

Thorsten Gehrke, Medical Director at the Helios Endo Clinic in Hamburg, one of the biggest clinics for endoprosthetics in Germany, remains skeptical: “I don’t condemn robotics in the operating room, but it’s too early to invest in surgical robotics.”

The fact that there are no long-term studies on the subject leaves him skeptical. A survey from Philadelphia additionally showed that hundred percent of the authors who publish in this area, directly or indirectly cooperate with the manufacturing firm, for example because advisory services have been accounted for or because implants from the same company have been bought. He doesn’t know any independent investigation in robotic-assisted knee surgery.

“That’s what I would say if I wanted to prevent innovation”, Hedrich from Schloss Werneck responds to Gehrke’s criticism. How could a long-term study be possible for this young technology? And of course they cooperate with the manufacturer, because the robotic arm cannot read out the prostheses from another supplier.

For many doctors, robotics in the operating room is an emotional subject, because the robot impacts the authority of the head surgeon in the mostly hierarchically organized operating room. Treatment by the chief physician is a highly demanded additional insurance. Will it be replaced by treatment by robots?

The opponents of robotics scored a point last year in urology, a related science. For prostate surgery, a distant relative of the knee surgery robot is used, the Da Vinci robot. More than one hundred hospitals in Germany already acquired the two million euro Da Vinci robot whereas there are only fifteen clinics that have a knee surgery robot.

No additional costs for robotics-assisted knee surgery

Since Da Vinci has been launched in 2000, there are already long-term studies on its effectiveness. An important one from 2019 has been conducted by the Martini Clinic Hamburg. It is renowned worldwide, even patients from Ghana go there for an operation. The results of the study show: patients who had a robotic-assisted surgery don’t feel better in the long term, but just as well as patients who underwent conventional surgery. If you still want to be operated with the Da Vinci robot at the Martini Clinic, you have to pay 2,000 euros yourself. There are no additional costs for robotic-assisted knee surgery.

“Patients associate higher precision with the surgical robots and hope for a better outcome. That’s why robots are also a marketing tool, let’s not forget that”, says Thom Rasche, medical technology expert and managing partner at venture capital investor Earlybird Health. He would recommend the acquisition of a surgical robot for knee surgery to hospitals specialized in endoprosthetics to position themselves on the market over the competition. He doubts whether the investment is worthwhile for a smaller hospital.

Sankt Marien Hospital Buer in Gelsenkirchen is one of these smaller hospitals. Nevertheless, Awakowicz believes that purchasing the robot was the right decision. “Our clinic is situated in the middle of the Ruhrgebiet and the competition is fierce. If I can convince patients with the robot to come to us, it will be a worthwhile investment.”

In Gelsenkirchen, patients suffering from knee arthrosis can choose a robotic-assisted intervention on the knee in the future. However, the clinic in Gelsenkirchen is not the only to offer robotic-assisted knee surgery. There are several hospitals in Germany that purchased this surgical system.