Top Innovations in Spine Surgery
HSS experts are harnessing creativity, technology and data to enhance every aspect of spine surgery. This includes advances in complex operations to repair the spine, whether they are focused on nerve decompression, spine stabilization, spine realignment or a combination of these aims. Here are highlights from a dozen of the most innovative projects that HSS surgeons are pursuing right now, as chosen by HSS Spine Co-Chiefs Andrew A. Sama, MD, and Harvinder S. Sandhu, MD, MBA.
Over decades of research, HSS has refined its tools for predicting who will benefit from spinal fusion surgery. “The goal is to do it at the right time for the right indication,” says spine surgeon Alexander M. Hughes, MD. Thanks to these tools, 95% of patients who undergo spinal fusion surgery at HSS have excellent outcomes, Dr. Hughes says.
Experts at HSS have utilized reams of patient data to develop decision trees that can be applied to every individual who comes in for evaluation.
Their research has revealed three orthopaedic conditions for which patients most clearly receive benefits from spinal fusion surgery: spondylolisthesis; deformities of the spine, including those caused by conditions like scoliosis; and fractures due to disease or injury. Patients who don’t meet the threshold for fusion surgery can receive less-invasive procedures or be guided toward other forms of treatment.
Innovations in diagnosis and imaging ensure that the best surgical approaches are provided for each patient. “In addition to looking at x-rays, MRIs and CT scans, we look at the quality of the bone as a measure of how much force the bone can sustain with regard to instrumentation and realignment,” says spine surgeon Federico P. Girardi, MD. Before surgery, HSS clinicians also use imaging to assemble a complete picture of each patient’s supportive tissues — the muscles, tendons, ligaments, skin and dura. “Thanks to all the research we’ve done in this area over the past 20 years, these surgeries have become much more predictable,” Dr. Girardi adds.
Thanks to all the research we've one in this area over the past 20 years, these surgeries have become much more predictable.
Once a patient is indicated for surgery, HSS clinicians focus on maximizing their biological capacity for healing. This includes using quantitative computed tomography, a more precise technique than DEXA scan, to learn as much as possible about bone density within the vertebral building blocks. Metabolic panels are used to assess vitamin D levels and bone turnover rates. If a potential problem is identified, patients can get medications before and after surgery to help with bone healing. HSS has led the way in developing medical interventions to improve bone healing after fusion surgery.
Even when fusion surgery is successful, patients may have additional spine problems down the road. “It doesn’t mean that something failed,” Dr. Girardi says. “It’s just the natural history of that patient, and it’s based largely on their genetics.”
We hope that one day we’ll have the ability to predict what the future may hold for each patient.
Collecting enough data to be able to uncover these genetic effects is a challenge, but one that experts at HSS believe is important. “We hope that one day we’ll have the ability to predict what the future may hold for each patient, and that we’ll find predictive genes that ultimately allow us to stop the cascade of degeneration,” Dr. Girardi notes.
HSS is a pioneer in using robotics in complex spinal surgeries like fusions. “The surgical robot helps us be more efficient with our surgical techniques,” says spine surgeon Sravisht Iyer, MD. “A big benefit of the robot is that it makes these procedures more reproducible and reliable.”
HSS is also one of the few hospitals that includes robotic surgery as part of its fellowship training. “The ability to train our fellows using these technologies is a crucial differentiator for our program,” Dr. Iyer adds. “It allows us to involve the fellows in more portions of the case, including preoperative planning and complex instrumentation. Training fellows to use these cutting-edge technologies allows us to ensure HSS is producing the next generation of leaders in the field of spine surgery.”
Training fellows to use these cutting-edge technologies allows us to ensure HSS is producing the next generation of leaders.
One of the key innovations enabled by the robot is the use of single-position spine surgery. In these procedures, surgeons are able to approach the spine from multiple different exposures without having to change the patient's position. This helps reduce the time spent in the operating room while still providing optimal outcomes for patients.
“When the patients are on their sides, we can approach the spine from both the front and the back,” Dr. Iyer says. “This flexibility allows us to maximize the advantages of each approach. Approaching from the front provides us with a large surface area for bone fusion and also produces better alignment of the spine.
This flexibility allows us to maximize the advantages of each approach.
Whereas approaching from the back allows us to place screws and rods to maximize stability and help ‘lock in’ this alignment.”
Traditional dual-approach procedures require that patients’ incisions be closed up after the anterior portion of the surgery before being turned over for the posterior portion.
By eliminating this step, single-position surgeries significantly reduce the amount of time the patient is under anesthesia. These procedures are not without complexity, though. “Single-position surgeries require an important collaboration between orthopaedics and the vascular surgeons, as well as coordination with anesthesiology,” Dr. Iyer adds.
During minimally invasive surgery, neuromonitoring probes are important for helping to guide instrumentation and indicate proximity to the nerves. “In some ways, performing minimally invasive spine surgery is like building a ship inside a bottle,” Dr. Girardi says. “But thanks to data on thousands of patients who have been treated with these techniques, we’re able to understand the benefits and limitations for each patient, which enables us to offer them the best outcomes.”
Advanced imaging studies, including CTs and MRIs, also help with navigation during surgery by enabling the creation of a three-dimensional map of vital structures to serve as a point of reference. “Historically, spinal surgery required bigger, open incisions, which allowed us to see the spinal anatomy directly,” says spine surgeon Darren R. Lebl, MD, MBA.
"Technologies like surgical navigation let us 'see' the spinal anatomy at the time of surgery on essentially a 3-dimensional map. This allows less disruption to tissues while using very small incisions. Also, direct feedback from surgical navigation is very useful in training residents and fellows to do surgery safely and effectively."
Technologies like surgical navigation let us ‘see’ the spinal anatomy at the time of surgery on a 3-dimensional map.
In the near future, Dr. Lebl plans to expand the use of these technologies into the area of augmented reality, which allows surgeons to view an overlay of the surgical anatomy mapped directly onto the patient instead of having to look up at a monitor. The digital overlay can be viewed through a surgical microscope or loupe. “The technology to do this is already here,” he notes. “This is very exciting, and it’s really the future of surgery and surgical education.”
Dr. Lebl points out that despite the benefits of technology, nothing is more important than the skill and judgment of the surgeons who use it. “Technology helps us to navigate, but it is an adjunct for skill, not a replacement,” he says. “As the top musculoskeletal hospital, we at HSS are uniquely positioned to make sure we are integrating these new technologies optimally, in the safest and most effective manner.”
With the ongoing opioid epidemic, limiting opioid use after surgery is an important goal. In a recent study, Dr. Iyer looked at whether giving patients intravenous acetaminophen or ketorolac after lumbar spinal fusion surgery could reduce the need for opioids. Because of concerns about postsurgical bleeding, as well as the potentially deleterious effects on bone healing, use of anti-inflammatory drugs in this setting traditionally has been limited.
In a placebo-controlled trial, Dr. Iyer’s team found that these drugs reduced the need for postsurgical opioids by 50 percent, with ketorolac working slightly better than acetaminophen. There was no difference in complication rates among the three groups. Patients receiving ketorolac were also able to leave the hospital sooner; they had a shorter hospital stay compared to the placebo group.
Because of the possible negative influence on bone healing, the use of these drugs was limited to no more than 48 hours. “We’re still looking at data related to the rates of healing,” Dr. Iyer explains. The work won the 2019 Whitecloud Award for Best Clinical Paper from the Scoliosis Research Society as well as an award for Best Clinical Paper from the Society for Minimally Invasive Spine Surgery.
Experts at HSS are using data collected over decades to focus on ways to reduce costs. Among the factors addressed are implant costs, length of hospital stay, operation times and complication rates. “We asked, 'What are the characteristics of these cases that we would consider optimized across all of these different areas?’” notes spine surgeon Han Jo Kim, MD, who has led these efforts. His team used data science to tailor a treatment pathway that they then tested with 25 patients.
By bringing the cost of care down, we can increase the value proposition of these big, complex cases.
In addition to applying the changes in the delivery of pain medication developed by Dr. Iyer, this optimized approached focused on early mobilization after surgery, increasing physical therapy visits during hospitalization from two to three times per day and minimizing blood loss during surgery as well as the length of time spent in the operating room.
For patients who received surgery using this optimized pathway, the length of stay went from an average of 6.5 days to 3.8 days. More remarkably, discharge to rehabilitation versus to home went from 40% down to just 3%. “Through this pathway — and thanks to all the infrastructure at HSS that helped us to develop it — we were able to effectively decrease the cost associated with the episode of care for these patients undergoing complex spine surgery,” Dr. Kim says. “At the end of the day, by bringing the cost of care down, we can increase the value proposition of these big, complex cases.”
Dr. Lebl says that doing spinal surgery minimally invasively through smaller incisions has the potential to improve patient recovery times so that they can get back to what they love to do. Limiting the surgical recovery period, lowering the inpatient length of hospital stay, and faster healing times is proving to be a more cost-effective method to treat spinal conditions. The ability to improve spinal surgery recovery and outcomes is greatly enhanced by integrating advanced imaging modalities and robotic technology into the operating room.
Traditionally, scoring from patient-reported questionnaires has been used to assess functional outcomes after surgery. Increasingly, HSS surgeons are aiming to utilize wearable technology and mobile apps to track patients’ activity levels. “Let’s say that before surgery, a patient is walking 2,000 steps per day. After surgery, an app on his phone can tell me he’s up to 10,000 steps per day,” Dr. Kim says. “That tells me that I’ve fixed his problem so well that his level of function has increased by five times.”
HSS is currently working to develop apps that can track patient progress and make care more efficient. These apps require extensive research and design in order to ensure that the parameters being measured are useful and accurate in assessing patients’ progress. “Patients can answer all the questions we want them to, but nothing is as good as a true, objective assessment of what they’re doing day to day, to see if they are getting ‘back in the game,’” Dr. Kim adds.