Surgical robots are hot. They appeal to healthcare facilities as a new technology that can be added to their high-tech portfolio. Orthopedic robots, which assist the surgeon with selected tasks by guiding the movements of surgical instruments during an orthopedic procedure, are no exception. However, the acquisition and use of these systems must be approached with caution. Before investing in an orthopedic robot, you’ll need to thoroughly assess your situation to determine whether the system can both add value to patient care and boost your bottom line. Each hospital is unique, and considerations vary from facility to facility.
Types of Surgical Robots
Surgical robotic systems can be broadly divided into two groups: those designed to perform a number of different minimally invasive surgery (MIS) procedures, and those — including orthopedic robots — designed to focus on specific procedures or a particular surgical specialty.
Systems can also be classified based on the amount of autonomy the robot has during a procedure:
- Active surgical robots perform a surgery according to a patient-specific plan programmed before the procedure. The surgeon supervises the robot intraoperatively and intervenes if necessary (e.g., pausing, stopping, recalibrating), but cannot physically control the actions of the robot during the procedure. In this scenario, each procedure is uniquely planned and programmed.
- Semiactive surgical robots allow the surgeon to hold and directly control the surgical instrument, but prevent the instrument from moving outside of the preoperatively defined physical boundaries.
- Telemanipulation surgical robots enable the surgeon to remotely control the system through hand/foot controls.
Currently, orthopedic surgical robots are available that are used for total hip arthroplasty (THA), total knee arthroplasty (TKA), partial knee resurfacing (PKR), spine implant placement (predominantly pedicle screws), and brain implant placement. Different robots have different capabilities; no one system can perform every type of procedure.
Claimed Clinical Benefits of Orthopedic Robots
Orthopedic robots are intended to improve patient outcomes in either of two ways:
- By improving the accuracy of implant placement. The rationale is that by increasing the accuracy of the procedure, hospitals will see a reduction of postoperative complications, such as premature implant failure and the need for revision surgery, and patients will experience improved function, less pain, and decreased length of stay.
- By reducing the invasiveness of the procedure. Some orthopedic robots are designed to replace open surgery with MIS, while other systems are designed to replace a major open procedure with a more minor one. For instance, Mako’s RIO (Robotic Arm Interactive Orthopedic System) enables surgeons to perform the minimally invasive PKR procedure on some patients instead of TKA.
Procedural Workflow
Before Surgery
The patient undergoes a CT scan, and the robot’s workstation uses the CT images to create a 3-D planning model of the joint of interest. These 3-D images are used to determine the surgical approach, the type of instrumentation to use, and the optimal implant design and size.
During Surgery
One universal step for all orthopedic robots is system registration, which creates a mapping between the CT image coordinates and the robot coordinates and thus allows the system to align the robotic arm with the patient’s anatomy. A tracking camera or a mechanical tracking arm can be used to map the robot’s position with the CT images.
Once registered, the system will either autonomously perform the surgical task (if active) or guide the position of the surgeon’s tools (if semiactive). The system’s video monitor displays the position of the patient’s joint and the surgical tool, along with other parameters, so that the surgical team can track the robot’s progress.
Typically, an orthopedic robot, whether active or semiactive, is involved in only one task during the procedure. Such tasks include bone resurfacing, milling bone cavities, and positioning of traditional instruments. The rest of the procedure, including site preparation, incisions, implant insertion, and closure, is performed as it would be in traditional surgery.
After Surgery
The robot must be moved from the patient bed, sterile drapes must be removed from the robot, and the robot-specific consumables must be sterilized.
No major changes to the patient’s postoperative care are necessary compared to traditional surgery.
Key Clinical and Financial Considerations
The Data on Efficacy
Many clinical studies that assess the performance of orthopedic robotic systems are sponsored by the supplier, creating obvious conflict-of-interest concerns. Also, the usefulness of each study depends heavily on the study design. Randomized controlled trials (RCTs) are the gold standard study methodology; however, few RCTs have been published on orthopedic robotic surgery. The bulk of the clinical data ECRI Institute has assessed comes from observational studies. Most observational studies show that robotic-assisted orthopedic surgery improves the accuracy of the procedures compared to traditional surgery. However, there is no long-term clinical data (i.e., 10 or more years) to substantiate the claim that robotic-assisted surgery provides long-term patient benefits and improves implant survival rate.
If few or no RCTs are available, an acceptable alternative design is an observational study. In these studies, as many patients as possible receiving either treatment are tracked, either prospectively or retrospectively. This design allows more patients to be studied, and the studies are easier and less costly to conduct — and are therefore more numerous. However, observational studies are susceptible to selection bias and the inability to identify or account for confounders that may compromise the results. Planned observational studies can reduce both bias and confounders compared to observational studies that were not planned.
Reimbursement
Currently, no additional reimbursement or specific billing codes are available for the use of robotic-assisted technology. For example, robotic-assisted TKA procedures are billed under existing traditional reimbursement codes for TKA. Whether codes will be developed in the future is unknown. It is possible that codes could be proposed if robotic-assisted surgery is viewed as significantly improving the course of patient care or as resulting in long-term savings.
If the development of billing codes for robotics follows the historical pattern of laparoscopic surgery, robotic-specific billing codes could emerge eventually. However, the soonest this could happen would be several years from now because of the time lag between generating sufficient supporting data and proposing, establishing, and implementing codes.
One factor that commonly drives medical device adoption — reduced 30-day readmission rates — is not likely to apply in the case of orthopedic robots, since complications (other than surgical infection) following implantation may take years to manifest.
This article is an excerpt from a Health Devices article posted on ECRI Institute’s Health Devices System, Health Devices Gold, and SELECTplus membership websites on March 18, 2014. The full article includes more guidance on Orthopedic Surgical Robotics, reported problems, and market drivers and limiters. The article also includes a supplementary table explaining the key information on the three leading orthopedic robots. To purchase this article and its supplementary materials, or to learn more about membership programs, visit www.ecri.org, contact clientservices@ecri.org, or call (610) 825-6000, ext. 5891.
