Complex Spinal Surgeries Now Aided by Robotic Surgical System
This represents a major step in the long-term effort to bring robotics and navigation software to the treatment of patients at D-H.Timothy Ryken, MD, MS, FACS, FAANS, chief of Neurosurgery
Thanks to a robotic surgical system, Dartmouth-Hitchcock (D-H) spine surgeons can now implant screws more accurately and quickly into the spines of complex patients, reducing the amount of surgical time as well as radiation exposure. Among the patients benefiting from this new technology are those who have had more than one back surgery, have spinal deformities or have high body mass indexes (BMIs).
The Mazor X System was brought to D-H by Chief of Neurosurgery Timothy Ryken, MD, MS, FACS, FAANS, who used it to perform the first lumbar spinal fusion surgery last October. “Spinal robotics is a developing area and surgeons in D-H’s Neurosurgery Orthopedic Spine Team and the D-H Spine Center and Pain Management Center are in a unique position to assess the ultimate impact of this technology going forward,” says Ryken. Working with Kevin McGuire, MD, MS, section chief of the Spine Center, and Bruce Vrooman, MD, MS, section chief of the Pain Management Center, Ryken says, “This represents a major step in the long-term effort to bring robotics and navigation software to the treatment of patients at D-H.”
McGuire explains that the Mazor X System is a multifunctional arm, similar to the robotic arms used in automobile factories. Before surgery, a computerized tomography (CT) scan is taken of the patient’s spine and the system’s software maps it, showing where surgeons want to insert screws. After the patient is put to sleep for surgery, a pin is placed in their pelvic bone, which serves as a marker for the robotic system. Then two more x-rays are taken with a fluoroscopy machine, which is medical imaging that shows a continuous X-ray image on a monitor, much like an X-ray movie.
“This gives the robot all the views it needs to see the spine,” says McGuire, who notes that the technology is only being used for elective lumbar and thoracic surgeries. “Once it registers the information it needs, the robot gets attached to the table. Using the pin as a reference point, it maps the surface of the patient so it knows where it can and can’t go. Based on the preoperative CT, I have drawn and mapped out where the screws need to be placed and the software shows the angles of entry so you can plan your incisions. The robot is limited in what it can do for us, but it helps us put the screws in by providing a trajectory for them. The arm will then come out and line up perfectly with a vertebra.”
The robotic system has made lumbar and thoracic spinal surgery faster and safer for patients who have had more than one spinal surgery or who have a complex spinal deformity that can make placement of the screws difficult and time-consuming. Previously in these cases, multiple X-rays were required to accurately map their spines. Because these patients’ spine or anatomy is different due to their earlier spinal fusions or spinal deformities, it can make screw placement difficult.
“In cases where the bone anatomy is not the same, the robot is great because one screw is going in one way and another screw is often going in at a different angle,” says McGuire. “Every screw placement is different, and the robot makes it much easier and much safer, especially to get bigger screws in. If you’re putting in 20 screws, this can save a lot of time and radiation exposure.”
McGuire has also used the robot on patients with BMIs of 45 and above, or very muscular people. “For patients with high BMIs, the robot is helpful because it improves accuracy,” he says. “We encourage these patients to go through our Bariatric Medicine Program and lower their BMIs. But for those who have been through that program and haven’t significantly lowered their BMIs, this technology enables us to perform spine surgery, whereas before we may have had to turn these patients away.”
Robotic spinal surgery is currently being used only for complex cases since straightforward surgeries, such as those that require the insertion of just a few screws, don’t require this level of technology. “I think the capabilities of the robots will increase over time,” says McGuire. “But for now, it’s really helping in the more complex cases by decreasing the risk and facilitating patient care.”