Trends to Watch in Spine Surgery

Same-day spine is one of surgery’s hottest specialties thanks to several new technologies that are making complex surgeries simpler for surgeons, more accurate and safer to perform, and less painful for patients. Let’s look at the exciting developments that are helping to push more procedures to outpatient ORs.

• Restoring vertebrae height. Vertebroplasty and balloon kyphoplasty, the two most common treatments of vertebral compression fractures, have inherent drawbacks, according to Robert E. Jacobson, MD, a neurosurgeon and spine specialist with OMNI Spine Center in Miami, Fla.

Vertebroplasty involves injecting cement to stabilize vertebrae fractures. The treatment works in a high percentage of patients with non-displaced, compressive eggshell-like fractures. There are potential drawbacks to the technique. The cement solidifies the fracture and prevents further collapse, but also makes the bone harder than adjacent vertebrae, which are therefore more likely to fracture.

Balloon kyphoplasty was developed to address the inherent drawbacks of vertebroplasty, a balloon is slid into the fractured vertebrae and expanded to correct the deformity before the cement is injected into the space.

“Studies have shown that long-term correction of the deformity is ineffective, and the vertebrae will continue to collapse, resulting in further fracturing and recurrent pain for the patient,” says Dr. Jacobson.

Additionally, because the balloon makes a bigger hole in an eggshell fracture, surgeons must add more cement, which hardens the vertebrae and increases incidences of adjacent fractures. To solve that issue, attempts have been made to place structural support inside the vertebrae before injecting the cement.

The most recent is a titanium implant that resembles a car jack. Surgeons implant the device, and open it up to expand the fractured vertebrae before the cement is injected and holds the device open. Long-term studies have shown that the device maintains deformity correction with better pain control and less risk of adjacent fractures than previous treatments. It’s particularly effective in the treatment of vertebrae fractures at the junction between the ribs and the lumbar region, where there’s higher risk of deformity and continued collapsing due to the body’s natural movements.

Outpatient spine presents clear value in health care.
— Matt McGirt, MD

The device effectively maintains spinal height and deformity correction with less risk of adjacent fractures, representing a natural progression from earlier structural support devices, which tended to be more difficult to implant.

Surgeons pre-size the implant based on measurements obtained using the pre-op CT scan of the patient’s spine anatomy. They then place it directly under the fracture through a 3.4mm to 5.8mm cannula — compared with the 1.8mm to 2.5mm cannula required for vertebroplasty and balloon kyphoplasty — and slowly expand it until it restores the height and corrects the deformity of the fracture. Once it’s deployed and locked in place, the surgeon injects cement into the vertebrae body.

• Lumbar fusions. When surgeons fuse a patient’s spine, they go through the back, the front or the side. Performing an anterior lumbar interbody fusion (ALIF) on a heavier patient involves a lot of dissection through a larger incision. Additionally, ALIF patients often have post-op problems with ileus.

That’s not the case with oblique lumbar interbody fusion (OLIF), during which surgeons reach the spine through a 2- to 3-inch incision. The approach allows for minimal dissection of muscle and tissue, and limited disruption of the underlying retroperitoneal organs.

Joseph Blythe, MD, a fellowship-trained spine surgeon in Nashville, Tenn., performed the city’s first OLIF 2 years ago. He says placing percutaneous screws under radiographic guidance is not difficult from the anterior or posterior approach, but doing it with the patient in the lateral position is nearly impossible.

“There’s a big push to do outpatient 1- or 2-level fusions from a single position,” says Dr. Blythe. Robotic-assisted, image-guided technology helps him accomplish that goal. “Using the robot is like placing a guided drill bit anywhere on the spine,” says Dr. Blythe.

Before procedures, he orders a CT scan, which shows the architecture of the spine, including bony elements and distances between vertebrae. That information is uploaded into the image guidance software, which lets Dr. Blythe pre-plan down to the millimeter and pitch in the bone where he’ll place every pedicle and cortical screw. During surgery, he can then place the screws exactly where he intends and at a specific pitch in the bone with minimal fluoroscopy guidance.

• Increased cervical mobility. Artificial disc technology increases spine mobility and puts less stress on adjacent discs. “The latest discs have changed how I approach disc replacement surgery because patients do so well afterward,” says Dr. Blythe.

“It’s difficult to find reasons not to do it. Patients present with herniated discs or stenosis at one or two levels, and two weeks later they’re back at work with no pain or symptoms.”

First-generation artificial discs resembled nothing more than a marble between 2 plates. Designs have progressed to a sliding bearing between 2 metal plates that mimic the motion of native discs — 5 degrees of flexion, extension, side bending and rotation — but can cause hyperflexibility of vertebral joints.

Dr. Blythe says the newer generation of artificial discs are designed with nano fibers woven in a ring around a soft cushion center to mimic more of a native’s disc structure, making them easy to use and best to achieve reproduceable results and good outcomes in the cervical spine and possibly in the lumbar spine. 

Few would argue the merits of providing quality and cost-effective care with good patient experiences, but the question remains: How do you do it right? Matt McGirt, MD, a minimally invasive spine surgeon in Charlotte, N.C., says 1- or 2-level lumbar discectomy, minimally invasive laminectomies, 1-level open or multilevel laparoscopic lumbar decompressive procedures can be done effectively and safely in the outpatient setting. “We know those procedures don’t require more than four hours of observation and recovery in an ASC,” he says.

Dr. McGirt says there’s growing evidence that 1- and 2-level anterior cervical discectomy and fusion (ACDF), and anterior cervical discectomy and fusion can also be done very effectively and safely without hospitalizing patients for post-op observation. He also points out minimally invasive transforaminal lumbar interbody fusion (TLIF) is beginning to emerge as an outpatient option.

Talking about the procedures that can be done in the outpatient setting is only part of the conversation providers should be having, according to Dr. McGirt. “Equally important is asking what procedures are appropriate for which patients — we’ve achieved successful outcomes with ASA I, II & III patients — and which facilities should be performing them,” he says.

Case volumes are slowly increasing. “The potential is huge,” says Dr. McGirt. “Outpatient spine is cost effective and presents clear value in health care. It’s just a matter of time until the market truly recognizes and rewards it. I expect a third of all spine surgeries to eventually be done in the ASC environment.” OSM