For years, posterior cervical spine surgery has required a trade-off. Surgeons could use lateral mass screws, the long-standing workhorse of posterior cervical fixation. The technique was familiar, broadly taught and generally safe.
But the fixation was not always strong enough. That weakness often forced surgeons into a workaround: make the fusion longer than the neurologic problem required.
John Rhee, MD, believes that trade-off may be starting to change. Dr. Rhee, professor of orthopedic spine surgery and neurosurgery at Atlanta-based Emory University School of Medicine, is among the surgeons studying renewed interest in subaxial cervical pedicle screws and pedicle inlet screws, techniques designed to strengthen posterior cervical fixation while potentially limiting the number of spinal levels that need to be fused.
“Lateral mass screws work reasonably well, but the major downside is that they tend to provide suboptimal fixation,” Dr. Rhee told Becker’s. That limitation matters most in complex cases.
A patient may have spinal cord or nerve compression from C3 to C7. If the surgeon also needs to correct cervical kyphosis, lateral mass screws may not provide enough strength to maintain the correction. The traditional answer has often been a longer construct, such as C2 to T2, because those levels offer stronger anchor points. The problem is that the operation becomes larger than the original neurologic disease.
“Now you’re making a bigger operation where you have to fuse more levels than the patient actually needs just to treat the neurologic problem,” Dr. Rhee said. For patients, that can mean more fused segments, less preserved motion and a bigger surgery.
On the other hand, for patients with sagittal plane deformity, improved subaxial cervical fixation can mean improved power for deformity correction
The promise of newer fixation strategies is not that every patient needs them. It is that some patients may avoid fusion levels they never needed in the first place.
Why stronger fixation matters
The logic behind cervical pedicle screws is straightforward. Pedicle screws have long been used in the thoracic and lumbar spine because they provide powerful fixation through strong bony corridors. In the cervical spine, the same principle applies.
The challenge is anatomy. The subaxial cervical pedicle is narrow. In some patients, it can be only a few millimeters wide. The vertebral artery lies on one side. The nerve root lies on the other.
“The problem with subaxial pedicle screws is that there’s a very narrow corridor for the screw to traverse,” Dr. Rhee said. “You have the vertebral artery on one side and you have the nerve root on the other, literally within a millimeter or two of this pathway.”
That is why use of these screws has never become routine in the U.S., despite being discussed for decades.
The potential benefit is substantial. The risk is real. For Dr. Rhee, that tension explains both the renewed interest and the caution.
The role of navigation
Navigation has helped make the conversation more realistic, but Dr. Rhee said technology alone is not enough. The cervical spine is highly mobile. Even small movements during surgery can affect accuracy. In a region where a few millimeters can determine whether a screw is safe, that matters.
“If you’re off by two millimeters, that could be a big problem,” he said. To address that issue, Dr. Rhee and colleagues have developed a method to temporarily stabilize the cervical spine during navigation-assisted screw placement. The goal is to reduce motion at the level being instrumented so the navigated anatomy more closely reflects the patient’s real position during screw insertion.
The early results have been encouraging.
“We’ve had much more ideally placed screws with no breaches, or minimal breaches,” he said. The point is not that navigation makes cervical pedicle screws easy. It is that navigation, when paired with the right technique, may make a historically difficult technique more reproducible.
The middle option: pedicle inlet screws
Dr. Rhee is equally interested in another technique: the pedicle inlet screw. The concept is more conservative than a full cervical pedicle screw.
A pedicle inlet screw does not traverse the entire pedicle. Instead, it begins laterally and aims medially toward the dense bone near the pedicle inlet. That trajectory distinguishes it from a lateral mass screw, which typically aims laterally.
“The bone near the pedicle tends to be very dense,” Dr. Rhee said. That density can provide stronger purchase than a traditional lateral mass screw, even with a shorter screw.
The result is a middle option. Not as strong as a full pedicle screw. Stronger than a lateral mass screw. Safer than traversing the pedicle.
“It’s not quite as strong as a pedicle screw, but you get to avoid the risk of a pedicle screw and gain significantly better fixation than you would with lateral mass screws,” Dr. Rhee said.
For surgeons who are not ready to use cervical pedicle screws, or for cases that do not require maximum fixation, inlet screws may provide an important bridge.
Smaller constructs, better correction
The patient-level impact is where the technique becomes most meaningful. Since adopting these strategies, Dr. Rhee said he has been able to perform shorter constructs while avoiding unnecessary fusion levels.
“I can do shorter constructs that don’t fuse unnecessary levels for the sake of fixation,” he said.
He has also seen better ability to correct cervical kyphosis. The longer-term question is whether that correction lasts.
Dr. Rhee is studying whether pedicle screws are more likely than lateral mass screws to maintain deformity correction over time. His early impression is that stronger fixation may help preserve the correction achieved during surgery.
“You are fusing potentially fewer segments, gaining better initial correction and maintaining that correction better over time,” he said.
That is the central promise. Not less surgery in the usual sense. These are still significant operations. Dr. Rhee described them carefully.
“This is sort of a maximally invasive procedure, but it fuses fewer segments,” he said. That distinction matters. The goal is not to make a complex posterior cervical reconstruction small. The goal is to make it more precise.
Why caution still matters
For all the promise, Dr. Rhee repeatedly emphasized that these techniques are not for every surgeon or every case.
“Danger lurks on both sides,” he said, referring to the vertebral artery and nerve root surrounding the pedicle corridor. Cervical pedicle screws should be used selectively, he said, particularly in complex deformity cases or situations where stronger fixation may allow surgeons to avoid longer constructs.
They are not necessary for every routine posterior cervical fusion. Inlet screws, by contrast, may have broader use because they carry less risk than full pedicle screws while offering better purchase than lateral mass screws.
Still, Dr. Rhee recommends navigation for both.
With inlet screws, navigation helps surgeons aim toward the densest bone and maximize screw length. With pedicle screws, he said, navigation and proper technique are essential for safe, reliable placement.
“To safely and reliably place those, you need good navigation and good technique with the navigation,” he said.
A familiar adoption curve
Dr. Rhee sees parallels between cervical fixation today and thoracic fixation decades ago. When he was a resident in the 1990s, thoracic pedicle screws were not routinely used. Many surgeons considered them too dangerous. Hooks and wires remained common, despite offering weaker fixation.
Today, thoracic pedicle screws are standard. The shift happened because the technique worked better, surgeons became familiar with it and the field learned how to place the screws safely and reproducibly. The cervical spine may follow a more cautious version of that trajectory.
He is careful not to suggest the cervical spine is the same. Cervical pedicle screws are more technically demanding and riskier than thoracic pedicle screws.
But the history is instructive. A technique once considered too dangerous can become standard when training, technology and evidence align.
What still needs to be proven
The evidence base remains early. Dr. Rhee said he and others are studying outcomes, accuracy, safety and durability, but he does not want the field to overstate what is known.
“I don’t want to make it sound like everybody should be doing these screws on every single case,” he said. The preliminary results are promising. The long-term data is still needed.
That is especially important because posterior cervical fixation sits at the intersection of technology, anatomy and judgment. A stronger screw is only useful if it is placed safely and used for the right reason.
The next five years
Five years from now, Dr. Rhee hopes posterior cervical fixation will look different. Not because every surgeon uses cervical pedicle screws. Not because every patient receives the newest technique. But because the field has better data, better training and more options.
He envisions surgeons learning these techniques through courses and structured education, developing familiarity with inlet screws and pedicle screws, and using them when the anatomy and pathology justify the added fixation.
“I would hope that we have good data on the efficacy and safety of these screws,” he said.
The future, in his view, is not universal adoption. It is appropriate adoption. Cervical pedicle screws may serve as the strongest option when maximum fixation and deformity correction are needed. Pedicle inlet screws may become a safer, more accessible option when surgeons want better purchase than lateral mass screws without the full risk of traversing the pedicle.
The work ahead is determining which patients benefit most. For decades, posterior cervical fixation has forced surgeons to balance safety, strength and the length of fusion.
Dr. Rhee believes the field may be entering a new phase, one where stronger fixation allows surgeons to be more selective, more precise and, in some cases, less willing to fuse levels simply because the old anchors were not strong enough.
That may be the real frontier. Not just putting in a stronger screw. Using better fixation to avoid doing more surgery than the patient actually needs.
At the Becker’s 32nd Annual Meeting: The Business and Operations of ASCs, taking place October 29-31 in Chicago, ASC leaders, surgeons and healthcare executives will explore strategies to drive growth, enhance operational performance, navigate reimbursement challenges and prepare for the future of ambulatory surgery. Apply for complimentary registration now.
