With innovative alternatives to traditional spinal fusion techniques, specialists in the Department of Orthopedic Surgery are improving outcomes for ortho-spine patients, applying leading-edge robotic and non-fusion tethering technologies to deliver better long-term function—faster.

Single-Position Approach Reduces Length of Stay, Optimizes Healing

A change in patients’ operative position is enabling surgeons to more effectively reach treatment targets during spinal fusions for conditions such as spinal stenosis and spondylolisthesis. The new technique, single-position anterior–posterior lumbar fusion surgery (SPLS), allows surgeons to complete the operation with the patient lying on one side—facilitating both more efficient short-term healing and better long-term function. “With the single-position approach, we can achieve better height restoration, especially for slipped disks where the vertebrae shift out of position,” explains Themistocles Protopsaltis, MD, associate professor in the Departments of Orthopedic Surgery and Neurosurgery, chief of the Division of Spine Surgery, and co-director of the Spine Center at NYU Langone. “It gives us more powerful anatomical control to restore disks to their normal alignment—which is more likely to heal and eliminate problems patients can experience later due to segment degeneration.”

In the single-position approach, larger implant cages can be placed in a more optimal location, along the weight-bearing cortical bone, to provide greater structural support. As the traditional cages placed posteriorly sit in the softer part of the vertebra where they can settle, this placement is more likely to sustain functional improvement, especially in patients with poor bone quality.

The newer approach often involves multidisciplinary collaboration, with a dedicated vascular surgeon first performing the anterior approach through the lower abdomen or through a lateral incision, parting the hip flexor muscles and reaching the treatment target. Then the spinal surgeon completes the disk removal and vertebral column reconstruction.

Robot Assistance Enables Further Precision

In tandem with SPLS, Dr. Protopsaltis and colleague Aaron J. Buckland, MD, associate professor in the Department of Orthopedic Surgery, are applying robot assistance to more precisely navigate spinal anatomy and place pedicle screws to complete the fusion. Placement is planned in three dimensions along the challenging spinal anatomy, the robot merging with preoperative CT imaging to achieve high-precision placement. The robot-assisted technique provides closer targeting, reducing the risk of complications such as nerve pain or weakness. It also eliminates the previous need for more extensive intraoperative fluoroscopy to guide placement of the screws, reducing overall radiation exposure to both the patient and the surgical team.

Even accounting for time to refine the robot application, the single-position approach has demonstrated reduced in-surgery time and complications, and faster patient recovery.

“This practice-changing technique is not only just as safe and effective as the alternatives, but also a less invasive approach that has distinct benefits over and above the traditional method, including improved operating room efficiency, reduced length of stay, and reduction in postoperative ileus,” says Dr. Buckland.

New Non-Fusion Option Sustains Function for Adolescents with Scoliosis

Separately, a vertebral body tethering (VBT) technique pioneered by spine specialists is enhancing outcomes in idiopathic adolescent scoliosis by circumventing fusion entirely. The alternative method, led by Juan C. Rodriguez-Olaverri, MD, PhD, clinical associate professor in the Department of Orthopedic Surgery and director of early-onset scoliosis, involves approaching the spine anterior through the thoracic cavity, sparing the muscles and joining the vertebrae with a U.S. Food and Drug Administration (FDA)–approved flexible polymer cord.

The new technique involves a process called growth modulation. It corrects curvature by partially restraining one side of the spine, guiding future growth, and allowing the spine to continue straightening. During the procedure, titanium screws are placed on the side of the spine that curves outward and secured with a flexible cord, or tether, along the other side. When the cord is pulled taut, it compresses the adjacent screws to help straighten the spine. NYU Langone is one of only a few centers in the world using this technique, and the first to regularly use intraoperative CT imaging navigation for screw placement to enhance safety and efficacy.

“With VBT, the spine can continue to move and bend, allowing greater comfort and freedom of movement, maintaining the quality of life these patients had before surgery,” notes Dr. Rodriguez-Olaverri. “And unlike traditional spine fusion, it leaves future treatment options on the table, if needed.”

“With VBT, the spine can continue to move and bend, allowing greater comfort and freedom of movement, maintaining the quality of life these patients had before surgery,” notes Dr. Rodriguez-Olaverri. “And unlike traditional spine fusion, it leaves future treatment options on the table, if needed.”

Because it leverages spinal growth, the VBT method—also known as anterior scoliosis correction (ASC)—is well suited to younger patients who are still growing. Many of the patients who have the procedure are dancers and gymnasts who rely on movement during peak adolescent years—for whom fusion could be career ending. As more data support the safety and effectiveness of the VBT approach, it offers a movement-sparing alternative for these patients.

With the functional benefits of this less invasive approach, postoperative patients experience freedom of movement, with a return to previous activities typically possible at six weeks post-surgery. All patients can walk and climb stairs before discharge from the hospital. The VBT alternative also offers visual improvements to the spine and leaves a smaller scar—a positive outcome in a patient cohort with documented psychosocial impacts from the condition.

Dr. Rodriguez-Olaverri—himself diagnosed with scoliosis during his adolescence—has been promoting the use of a second cord, to minimize the risk of cord breakage and the need for a repeat procedure without the loss of flexibility. “With the support of a multidisciplinary care team, we are helping to treat more and more of these patients without compromising their quality of life,” he concludes.