Cost-Effectiveness of Robotic and Navigation Systems

Introduction

Substantial technological innovation has been made in spine surgery over the last few decades. This innovation has ranged from improvement in operative techniques, surgical implants, and biologics to improved accuracy with image-guided navigation and robotics. Robotic assistance is being increasingly utilized across multiple surgical specialties including urology, obstetrics and gynecology (OB/GYN), orthopedics, and neurosurgery. Although the utilization of robotics in spine surgery is still in its nascent stages, the recent literature has demonstrated that it has the potential to revolutionize safety and accuracy, not just for the placement of spinal instrumentation, but also to complete other critical operative steps while minimizing radiation exposure to the surgical team. However, while many providers and institutions are acquiring various surgical robots, there have been reports that the technology has failed to penetrate into routine practice. To demonstrate its value in healthcare, any new technology must demonstrate cost-effectiveness in addition to quality or improvement in outcomes. Spine providers have been hesitant to incorporate robotics and navigation into routine surgical care due to the notion of substantially higher costs associated with the acquisition of these newer guidance platforms. In today’s pay-for-performance era, spine surgeons are under increasing pressure and scrutiny to develop measures that control pricing and allow increased accountability for surgical performance. The incorporation of robotic and navigation systems into routine practice might allow implementation of such value-based spinal care.

In addition to quality and safety, the cost-effectiveness of robotic surgery has been evaluated within other surgical specialties such as urology and OB/GYN. The cumulative evidence has significantly changed practice patterns in urologic surgery. Such cost-effectiveness analyses are essential to obtain a more balanced perspective of practice utility and are imperative to design and effect solutions to improve performance. However, such analyses are limited in the realm of spine surgery. In this chapter, the authors discuss the available evidence on the cost-effectiveness of robotics and navigation in spine surgery and provide an overview of the mechanisms regarding how the assimilation of such platforms into the daily surgical workflow could provide long-term cost savings.

Scope of Robotic and Navigated Spine Surgery

A variety of image-guided navigation and robotic platforms are currently available in the spine surgery market. Although navigation and robotic guidance have historically been mutually exclusive, the newer platforms allow the integration of the two modalities to facilitate real-time feedback in addition to the placement of instrumentation along pre-planned trajectories with the use of a robotic arm. Each type of platform achieves stereotaxy through some form of preoperative or intraoperative radiographic imaging such as x-ray, MRI, computer tomography (CT) or three-dimensional (3D) fluoroscopy to generate a comprehensive spinal map for precision and accuracy. Intraoperative cone-beam CT or O-arm (“computer-assisted navigation”) and 3D fluoroscopy (“virtual fluoroscopy”) are the most commonly utilized imaging modalities in modern surgical navigation systems. Both allow frameless stereotaxy with real-time, navigated feedback of instruments such as tubular dilators, screwdrivers, drills, and awls. Examples of such systems include the Airo Mobile Intraoperative CT-based Spinal Navigation (Brainlab©, Feldkirchen, Germany), Stryker Spinal Navigation with SpineMask© Tracker, and SpineMap Software (Stryker©, Kalamazoo, Michigan), StealthStation Spine Surgery Imaging, and Surgical Navigation with O-arm (Medtronic©, Minneapolis, Minnesota), and Ziehm Vision FD Vario 3D with NaviPort integration (Ziehm Imaging©, Orlando, Florida). It is essential to note that instrument maneuvering with these systems is still entirely surgeon-dependent with the navigation system merely providing anatomic feedback.

Robotic systems allow user-operated trajectory planning using radiographic guidance, following by “locking” of the robotic arm along the desired screw trajectory. This can be additionally aided by intraoperative navigation to allow real-time feedback in more recent platforms. Surgical robots can be divided into three types depending on the levels of assistance: (1) supervisory controlled systems, in which the robot performs actions based on a pre-planned trajectory under close surgeon supervision; (2) tele-surgical systems (e.g., da Vinci robot, Intuitive Surgical, Sunnyvale, Calfornia), which allow the surgeon complete control over the robot remotely; and (3) shared-control models with varying levels of simultaneous control between the robot and the surgeon. Most contemporary robotic systems utilized in spine surgery today are shared-control systems which allow the planning of stereotactic trajectories via preoperative or intraoperative imaging, which is then produced by the robotic arm followed by placement of the instrumentation by the surgeon.

In terms of volume, there remains significant potential in spine surgery for the utilization of robotic and navigation platforms that could justify the initial acquisition costs. From 2004 to 2015, the volume of elective lumbar spinal fusions increased 62.3% from 122,679 cases (60.4 per 100,000) in 2004 to 199, 140 (79.8 per 100,000) in 2015. The first commercially available robotic platform for spine surgery, the Mazor SpineAssist system (Mazor Robotics, Caesarea, Israel), gained FDA approval in 2004. However, it did not see significant utilization until 2011 with a small number of installations; fewer than 100 were installed by 2015. The number of procedures per system has been increasing steadily since then, implying greater penetration of spine robots in the operating room (OR), and, by 2015, over 3000 robotic spine procedures were performed annually in the United States. A similar trend has been noted for the da Vinci Surgical System in prostate and OB/GYN surgeries, with over 700,000 procedures performed in 2015. Apart from being the first robotic system to be utilized in surgical care, the da Vinci robot also served to popularize robotic surgery both among medical professionals and the general public. Following the integration of these technologies into their daily surgical practice, if hospitals responsibly market themselves as state-of-the-art spine surgery centers, they could potentially leverage the high surgical volume to offset the initial acquisition and maintenance costs while simultaneously improving patient safety outcomes and satisfaction. Improvement of patient understanding of the surgical procedure is also essential to allow increased utilization. The patients should be informed that the surgeon would still perform the critical aspect of the procedure with the robot serving as a “guidance” mechanism for improved trajectory planning and kinetic feedback.

While most of the current literature on robotics and navigation focuses on the placement of pedicle screws, there are multiple other applications that could provide a justification for increased utilization. Several studies have demonstrated the feasibility of image guidance systems in the surgical workflow for minimally invasive lateral lumbar interbody fusion (MIS-LLIF). Both navigation and robotics have also been investigated for the placement of S2-alar-iliac screws. The applications for these systems have also expanded to the resection of both primary and metastatic spinal column and intradural tumors, along with cases of spinal deformity. In addition to the surgical volume, such an expansion of scope for a wide range of clinical indications also provides an inherent basis for cost-effectiveness.

Cost-Effectiveness of Image-Guided Navigation Systems

There have been several studies that have demonstrated the costs and benefits associated with use of image guidance in the OR Mainly, the currently available literature has been focused on the cost savings associated with the use of image guidance for the placement of pedicle screws. The proposed mechanisms of cost-effectiveness include a reduction in the rate of revision surgery due to screw malposition and a reduction in OR facility costs due to the shorter operating time as a consequence of the shorter time required for each pedicle screw placement. In an analysis of 100 patients who prospectively underwent thoracolumbar instrumentation with 3D fluoroscopic image guidance compared to a historical cohort of 100 patients who underwent instrumentation without image guidance, Watkins et al. demonstrated cost savings of $71,000 per 100 cases due to the reduction in rate of revision surgery from 3% to 0% and shortened time for screw placement (OR costs: $93/min). The total cost of the navigation system itself was reported as $475,000. Each revision surgery cost the hospital as much as $23,000 for Medicare and ~$40,000 for private patients. Therefore, image guidance was deemed cost-effective in the long term with high surgical volume. Further, Costa et al. demonstrated that image guidance based on intraoperative CT (O-Arm) may be more cost-effective than is preoperative CT . The authors found a shorter mean time for each pedicle screw placement using intraoperative CT-based computer guidance (16 min vs. 28 min) with fewer intraoperative radiographs needed. The mean cost of the procedure with intraoperative O-arm CT was also found to be lower than preoperative CT (€6482 vs. €6738). Hodges et al. projected that the use of intraoperative O-arm guidance could lead to total cost savings of $40,595,000 nationally, assuming a 1% rate of return to the OR due to breached pedicle screws with conventional C-arm fluoroscopy, compared to none in the O-arm group that was observed in their analysis from a single institution.

Cost-Effectiveness of Robotics in Surgery