Are Robots for Spine Surgery Worth the Cost?

When a lumbar fusion is the best option for a patient, a minimally invasive surgery (MIS) using a spinal surgical robot may provide a new, safer alternative to traditional open spine surgery. Available research demonstrates that compared to MIS robotic surgery, open surgery patients undergo extensive muscle dissection, higher estimated blood loss, more postoperative pain, higher postoperative infection rates, longer hospital stays and healing time, and worse scarring.

Robotic-assisted spinal surgery is used for posterior instrumented fusions in which screws are implanted in the bones of the back. Indications for screw insertion include fusion surgery in the low back, mid-back, or neck. Robotic guidance systems may also be used for the surgical correction of scoliosis or kyphosis.

Robot-assisted spine surgery has many advantages, even with limited use, such as:

• Increased accuracy of pedicle screw placement

• Decreased radiation exposure to surgeons and surgical team (from fluoroscopy)

• Less tissue destruction than traditional surgery

• Advancement in AI and research could allow for more complicated procedures, such as dural closure or bony decompression

“Revision fusion and deformity seems to lend itself to the most potential benefits in our opinion,” say Todd H. Lanman, MD and Jason M. Cuéllar, MD of Lanman Spinal Neurosurgery in Beverly Hills, California. Drs. Lanman and Cuéllar currently use the Mazor X robot in their practice. They have been performing robotic-assisted surgeries since 2004, and have updated their robots as technology advanced.

Disadvantages of Robotic-Assisted Spine Surgery

The spine-assisted robotic surgery Industry is still in very new; therefore, there are not many surgery applications. With more research and the integration of advanced artificial intelligence (AI), more applications are expected in the future. Current disadvantages include:

• Patient outcomes in robot-assisted versus traditional surgery needs more research, say Drs. Lanman and Cuéllar

• High introductory cost: “Yes – cost was a very large hurdle. Luckily our surgery center, at which a relatively high volume of spine surgery is performed, was able to commit to the investment,” say Drs. Lanman and Cuéllar.

• Steep learning curve for some surgeons, though Drs. Lanman and Cuéllar had a different experience. “We did have some prior experience, but also received official training at a special cadaver lab. In our experience the learning curve was rapid and easily surmountable,” they say. “This may be because we both had extensive experience with open pedicle screw insertion, minimally-invasive percutaneous pedicle screw insertion and 3D-navigated pedicle screw insertion with the Medtronic O-arm Stealth system.”

• Potential technological glitches

• Yearly maintenance and disposables costs

In short, hospitals and surgical spine practices are the target market, and with good reason. There has been a rise in funding for research and development, increasingly rapid development in robotic surgical technology, and increased acceptance of minimally invasive surgeries.

The United States in particular has seen an increase in the number of surgical procedures annually with a forecast of this trend continuing through 2026. The U.S. also has higher purchasing ability because of hospitals, a solid healthcare infrastructure to support the market and the machines, and a rise in its geriatric population -all factors driving the spine surgery robot market.

For practices considering purchasing a robot, “The large investment required for this technology is going to make it very difficult for a small practice to make. Therefore, we recommend forming partnerships with other surgeons interested in using this technology. Discussing the purchase of the technology with the hospital may also be successful, as it can also be a local draw for patients and other surgeons to bring their cases to the hospital where the technology exists.” say Drs. Lanman and Cuéllar.

Medical robots generally fall into three categories:

1. Supervisory-controlled: allow the surgeon to plan the operation in its entirety pre-operatively; the robot then performs the operation under close supervision by the surgeon.

2. Telesurgical: allow the surgeon to directly control the robot and its instruments throughout the entire procedure from a remote location

3. Shared-control: the most often used type of robot, shared-control robots simultaneously allow both the surgeon and robot the ability to control instruments and motions

Surgery Center of Beverly Hills, where Drs Lanman and Cuellar are founding members and perform outpatient spine surgery, purchased the Mazor X robot in 2020.

Although their choice was based on prior experience, they don’t discount other surgical robots. According to Drs. Lanman and Cuéllar, “There are now a few different options for robotic spine surgery that are excellent. The Mazor, acquired by Medtronic in 2018, has been in use longer than any other system – since 2004, originally named the SpineAssist (Mazor Robotics Ltd, Israel). Our choice was based on our prior experience using the Mazor at our medical center, and our strong pre-existing relationship with the team at Medtronic.”

Mazor (Mazor Robotics Ltd., Caesarea, Israel)

SpineAssist® - The SpineAssist® was the first robot approved by the FDA (2004) for use in spinal surgery in the United States and remains one of the most widely used. Unlike newer robots, the SpineAssist cannot properly account for intraoperative movements by the patient. This problem has been corrected in new models by both Mazor and other manufacturers.

Advantages

• Shared-control robot

• Superior navigation to traditional intraoperative CAN

• Automatically positions its arm along a pre-determined trajectory resulting in lesser number of complex movements required by the surgeon

• Providing optimal positioning for screw insertion

• Six degrees of freedom of motion for surgical instrumentation

• Ability to include multiple arms to accommodate drill guide sleeves on each

Renaissance® - Mazor’s second-generation spine robot (2011) was intended to replace their SpineAssist. Both the SpineAssist and Renaissance are the most studied and most widely used spinal surgical robots. Note that they also both have faced problems with screw misplacement secondary to skiving.

Advantages

• Software and hardware improvements, such as better image recognition algorithms

• The ability to flatten bone around screw entry points before drilling, in preventing skidding of the guiding cannula on a sloped anatomy

• Accuracy rate is similar to SpineAssist (85 percent to 100 percent)

Mazor X® - The Mazor X® was released by Mazor in 2016. The structure of the workstation and mechanical surgical arm is similar to Mazor X’s predecessors. In 2020, Medtronic (Mazor’s current owner) warned of a potential detachment issue.

Advantages

• The biggest change is that the robotic arm has an integrated linear optic camera, providing multiple benefits:

  • An intraoperative 3D scan following the placement of a reference pin in the patient’s spine

  • Scan initiates the robot to perform a volumetric assessment of the work environment, allowing self-detection of its location and providing intraoperative collision avoidance

• Allows each vertebral body to be registered independently, resulting in each having its own accuracy

• Serial instead of parallel robotic arm

  • Increases work capacity of system

  • Increased range of motion

  • Reduced reliance on surgical tools

Medtronic/Mazor (Memphis, Tennessee)

Mazor X™ Stealth Edition – Medtronic purchased Mazor in 2018 and in collaboration released the Mazor X Stealth™ Edition robotic guidance system. Due to its recent release (2019), much research needs to be compiled about the use of this robot in order to provide accurate usage data and results.

Advantages

• Allows for pre-operative or intra-operative planning on a laptop or the workstation

• Customizable implant selection

• Optimal implant trajectories and 3D analytics

• Makes procedures more predictable through construct optimization

• Segmental vertebral body registration

• X-Align for sagittal and coronal deformities

• Rod passage and skin cut optimization

• Small operating room footprint

• Multiple robotic patient monitoring options

• Cameras map surgical site and create a "no fly zone" for optimal robotic movement

• Real-time visualization of the implant entering the anatomy

• Easier navigation achieved by taking a single non-radiographic snapshot image

Zimmer Biomet Robotics (Montpellier, France)

ROSA® Spine - The original ROSA® BRAIN robot (2012) was designed for cranial surgeries. Based on the initial brain version design, the ROSA® SPINE was approved by the FDA in 2016. The robot is similar to the Mazor X, with a free-standing unit, a robotic arm and navigation camera. Like the Stealth, this robot has not yet been widely reviewed in academic literature due to lack of data.

Advantages

• Robotic arm and navigation camera mounted to floor-fixable bases optimize and guide pedicle entry points and trajectories

• Preoperative CT scan produces 3D image reconstruction

• Preoperative and intraoperative scans are merged to plan 3D trajectory

• Stereoscopic camera can be used for navigation

• Cameras track patient movements and readjust the robot position in real time

Intuitive Surgical (Sunnyvale, California)

The da Vinci Surgical System® - The da Vinci was originally developed and FDA-approved in 2000 for general laparoscopic procedures. This robot uses a telesurgical model. The surgeon operates from a remote telesurgical booth with 3D vision screens. This model allows the robot to serve as an extension of the surgeon’s arm. Due to its long-term and wide use, the da Vinci has been widely studied. Research has demonstrated results of superior visualization and magnification compared to traditional laparoscopy.

Advantages

• Control grips for the surgeon

• Seven degrees of freedom

• Tremor filtering

• High-definition video

• Improved ergonomics

Globus Medical, Inc. (Audubon, Pennsylvania)

Excelsius GPS® - Cleared by the FDA in 2017, the Excelsius GPS® shows excellent potential for spinal surgeries. At the time of this publication, there is very little research regarding accuracy due to its recent FDA approval and short-time on the market. The robot is most similar to the Mazor X and ROSA.

Advantages

• Real-time intraoperative imaging

• Automatic compensation for patient movement

• Direct screw insertion through a rigid external arm – obviating the need for K-wires or clamps.

• Feedback provided instantly via robot’s monitor if drill skives or reference frame moves

If you’ve decided to purchase a robot, evaluating the disadvantages may be more useful, as they are generally the same regardless of model, with a few exceptions:

• Cost (up to $1,000,000 or more)

• Size and weight of the machine; OR footprint

• Steep learning curve

• Soft-tissue pressure on the instruments through a robotic arm can lead to skiving or deflection

Other Considerations

Just because a surgical robot is newer with more features does not mean it’s the right robot for your practice. An older, more cost-effective model may meet your needs and have the same success rate. Older models also have more evidence-based research to back-up their data.

You should also determine how many surgeries you perform on an annual basis where a robot would be of use. If the number of surgeries cannot be recouped by cost savings or procedural payments in a timeframe that works with your practice’s budget, then the purchase may not be a good choice.

Drs. Lanman and Cuéllar recommend practices form partnerships if they are considering purchasing a surgical robot, “We believe forming partnerships with local hospitals or groups that have the technology, or are interested in it, enabling the surgeon to try it out before making the purchase for their group’s facility.”

The cost of a surgical robot can be prohibitive if you aren’t a large practice or hospital. Also, more data is still required to provide evidence of the long-term value versus financial implications. Despite the drawbacks, using robotic systems in spine surgery can be cost-effective through potential reduced need for revision surgeries, lower infection rates, potential shortened patient length of stay, and shorter surgical time. Ultimately, these back-end cost savings are what pay for the robot.

In terms of cost to patients, insurance most often covers the use of the robotic surgery. “Aside from the disposable covers that the facility must purchase, the cost of instrumentation is the same. Therefore, we do not believe there is a difference in cost passed on to the patient,” say Drs. Lanman and Cuéllar.

In a retrospective study of 557 patients by Menger et al, one surgery center saved more than $600,000 due to a combination of:

• Reduced surgical time (MIS robotic procedures shaved off 3.4 mins per spinal level

• Reduced infections (4.6% infection rate with open surgery versus 0.0% with robotic)

• Avoiding revision surgeries (improved accuracy = 9.47 less revision surgeries)

Decreased risk to patients with difficult cases is one of the main values that say Drs. Lanman and Cuéllar have found with using a surgical robot. “Robotic assistance definitely takes some of the risk out of cases with difficult anatomy, such as deformity and revision surgery,” they say. “Once the entire surgical team is efficient at set up, robotic assistance can reduce instrumentation time, particularly for multi-level cases.”

Consider that when Mazor X launched, the Renaissance dropped in price from close to $1,000,000 to $550,000, inclusive of all the hardware and installation. Hospitals charge on average between $40,000 and $80,000 for a lumbar spine fusion. Therefore, between 10 and 12 lumbar surgeries are required to pay back initial purchase costs.

Note that annual service and maintenance costs need to be considered at an annual rate of 10% of the list price. Implants and all disposables are also an additional ongoing expense. A surgical robot is not a one-time investment.

Will (and Should) Robotic Surgery Become the Gold Standard for Certain Spinal Surgeries?

“We feel that while it is another very useful tool in our armamentarium, it should still come down to the expert preference of the spine surgeon,” say Drs. Lanman and Cuéllar. “We think it will be more commonly utilized as the technology improves and hopefully becomes more cost-efficient. For some cases we can still perform the surgery more efficiently without it. But as mentioned before, we think it will become more widely used for difficult deformity and revision surgery moving forward.”