Advantages and Disadvantages of Robotic Assisted Spinal Surgery: The 12 most Relevant Systems

Surgical procedures of the spine benefit from fine motor coordination, a highly experienced surgeon, and the best available technology. Robotic systems have been used in many surgical disciplines, including spinal surgery. This review will present the advantages and disadvantages of robot-assisted spinal surgery, as well as the most common applications and different types of robots used for spinal surgery. (Learn about 12 Robots for the Spine Surgery).The robotic systems most often used in spinal surgery are masterslave systems and trajectory assistance robots. To date, robotic systems have been used with favorable outcomes in several types of spinal surgery, including posterior instrumentation, tumor resection, and vertebroplasty. Robot-assisted spinal surgery is an ongoing investigational field, and new research directions may lead to the development of very different robotic surgical devices in the future.

Advantages of Robotic Assisted Spinal Surgery

Accuracy and Precision

Accurate image-guidance in spinal surgery can be used to identify the exact position and trajectory during a procedure and is one of the most important tools in the surgeon’s armamentarium. Screw misplacement can lead to instability as well as neurological, vascular, and visceral injuries. Misplacement-related complications are reported in1% to 54% of spinal surgeries,18 demonstrating a need for surgeons to improve accuracy and consistency in pedicle screw placement. These high complication rates are the main impetus for developing computerized navigation systems and robotic assisted spinal surgery. Robots can potentially help spine surgeons improve accuracy by positioning a guide tube over a preplanned target and can improve precision by scaling the surgeon’s hand movements and reducing tremor; robots also minimize exposure to radiation. Several retrospective analyses have shown comparable accuracy rates between robotic-assisted and conventional screw insertion techniques.

Minimal Invasiveness

In theory, robotic systems can improve intraoperative localization, especially in patients with more challenging anatomy, while allowing access through smaller incisions. The development of smaller and smaller robotic manipulators and camera systems that are capable of fitting inside very tight spaces make these capabilities possible. Minimally invasive surgery offers several advantages to the patient: smaller incisions, lower risk of infection, and minimal muscle retraction, which can decrease postoperative pain, opioid use, and the length of hospital stays.

Radiation Exposure

Another major theoretical advantage is that robotic-assisted spinal surgery, especially minimally invasive surgery, may reduce radiation exposure since robotic placement decreases the need for using intraoperative fluoroscopy. Radiation exposure as a health hazard to medical personnel is an ever-increasing concern.

Operative Time

Theoretically, if a robot enables easier access with rapid response and holds an accurate and precise surgical trajectory through a less invasive exposure, surgical time could be decreased. However, additional factors regarding operative time require consideration: additional setup time is needed to mount and register a robot, and planning time is needed for the surgeon to identify the desired trajectory. Current data indicate that the decrease in surgery time due to the performance of the robot is offset by the increased setup and planning time. Most available studies reported no significant time difference between robot-assisted and fluoroscopically guided procedures.

Disadvantages

The main disadvantage of robotassisted spinal surgery is its technological complexity relative to fluoroscopically guided surgery, which leads to a large increase in potential sources of surgical error. Some of these technological errors may be difficult for the inexperienced surgeon to recognize; therefore, poor outcomes may occur if the technology is relied upon blindly. A particularly troublesome error that has been documented with robotassisted techniques is poor accuracy between preoperative three-dimensional images and the real-time anatomy of the patient. The source of this error can be poor image quality, inaccurate registration, inaccurate or inadequate patient tracking, or a combination of these factors. In some reports, cases of noticeable inaccuracy were dealt with by simply reprogramming the screw trajectory a few millimeters by eye; in other cases, the screws were removed and repositioned by hand.

Uses of Robotic Systems in Spinal Surgery

Posterior instrumentation with pedicle screws and rods is by far the most common use for robotic systems in spinal surgery. As discussed previously, some authors have reported that the use of robotic localization to place screws and implants has increased accuracy and precision. Robotic systems have also been used successfully for other spinal procedures, such as tumor resections, vertebroplasties, anesthetic blocks, and revision surgery after previous spinal surgery, and for conditions such as spondylolisthesis, stenosis, spondylolysis, ankylosing spondylitis, vertebral fractures, and osteomyelitis.

Types of Robots

Two major categories of surgical robots, based on the input that is used to control movements, are used in spinal surgery: master-slave systems and trajectory assistance robots. Below, we describe one prominent, commercially available example for each of these two types. Robotic systems used for diagnostic or imaging applications were excluded from discussion.

Master-Slave Systems

With master-slave robotic systems, the surgeon fully controls and manipulates the master system and visualizes the operation on a video screen. The “slave” system consists of mechanical actuators that respond with some amount of computer processing to inputs (typically joystick movements) of the surgeon into the master system. The da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) is the most recognized and used master-slave robotic system. It was approved for general surgery in 2000 and has been used within the past few years in several types of spinal surgery, such as anterior lumbar interbody fusion, thoracolumbar tumor resection, transoral odontoidectomy, and paraspinal tumor removal, and it has been tested under several research protocols with great success. The da Vinci robot is comprised of 4 arms: 3 for surgical manipulation and 1 for a camera. Each arm has 6 degrees of freedom and is controlled by 2 hand controls and 2 foot pedals. It provides three-dimensional visual cues, enabling precise dissection and meticulous bleeding control by scaling the surgeon’s hand movement in relation to the robotic arm movement and filtering out tremor. The da Vinci robot also has a short learning curve and provides freehand movement and an ergonomic position for the surgeon. Compared with other robotic systems or traditional surgery, it allows excellent visualization. The increased magnification and illumination of the surgical field allows careful dissection of fine structures such as nerves and blood vessels, substantially improving patient outcomes. Conversely, a lack of haptic feedback to the surgeon and the inability of the surgeon to be stationed at the operating table are two notable limitations.

Trajectory Assistance Robots

Trajectory assistance surgical robots are designed to position an effector over a target for a precise stereotactic insertion procedure (Mazor). In some systems, the target, insertion site, and trajectory can be virtually planned on preoperative images, which may include plain radiographs, computed tomography, and magnetic resonance imaging. Virtual planning allows the surgeon to safely visualize the trajectory, avoid critical regions, and make changes if necessary. End-effector positioning is registered to a preoperative image and automatically adjusted by a control computer, which directs the robotic motor system based on its interpretation of intraoperative imaging. This robotic control ensures adherence to the virtually planned path. This type of robot is therefore capable of autonomously positioning itself based on image information and is capable of manually or automatically moving into alignment with a fixed trajectory relative to the patient while allowing the surgeon to manually control the surgical instruments.

Source: Robotics in Spinal Surgery: The Future is Here.BARROW QUARTERLY • Vol. 26, No. 1 • 2016 (Hector Soriano-Baron, MD Eduardo Martinez-del-Campo, MD Neil R. Crawford, PhD Nicholas Theodore, MD, FAANS, FACS)