The Art of Spine Surgery | Why How It's Done Matters
Surgical Philosophy · Precision · Patient Education
The Art of Spine Surgery —
why how it is done matters as much as what is done
Two surgeons. The same diagnosis. The same procedure name on the operative report. And ten years later, two completely different outcomes. One patient is skiing. The other is back in a surgeon’s office asking why nothing got better. The procedure was not the variable. The execution was.
The commodity trap —
why patients are taught to think about surgery the wrong way
When patients research spine surgery, they are typically searching for the procedure: ACDF, lumbar fusion, disc replacement, microdiscectomy. They find explainer videos, comparison articles, and hospital marketing pages that describe what the surgery involves. They learn that ACDF removes a disc and fuses the segment. They learn that microdiscectomy removes the herniated fragment. They conclude — reasonably, based on everything they have read — that the surgery is the surgery. That any trained surgeon performing the procedure will produce approximately the same result.
This is one of the most consequential misunderstandings in medicine.
The procedure is a framework. It describes the general approach, the anatomy accessed, and the broad goal of the operation. It says nothing about the hundred decisions made within that framework — decisions that are invisible to the patient, often invisible in the operative report, and entirely dependent on the judgment, philosophy, and technical precision of the individual surgeon performing them. The procedure is the recipe. The outcome depends on the chef.
I want to change how patients think about this. Not because it serves my interests — though I believe this approach produces better outcomes — but because patients who understand the nuance behind surgical technique are better equipped to ask the right questions, evaluate their options honestly, and ultimately make decisions that serve them well for decades.
“Spine surgery is not a commodity. The name on the operative report — anterior cervical discectomy and fusion — tells you almost nothing about what actually happened in the operating room.”
What surgeons decide
that no one tells you about
Between the first incision and the last suture, a spine surgeon makes dozens of decisions that are not captured in the procedure name, the consent form, or the discharge paperwork. Here are the ones that matter most to your long-term outcome.
The implant — size, height, and angle are not standard
Every spine surgery that involves an implant — an interbody cage, a disc prosthesis, a pedicle screw — requires the surgeon to select that implant. The cage that restores the disc space in a lumbar fusion comes in many sizes, heights, and lordotic angles. The choice matters enormously.
A cage that is too small for the endplate concentrates load on a small central zone of the vertebral body rather than distributing it across the full endplate surface. Over time, that concentrated load causes the cage to subside — to sink into the softer cancellous bone beneath the endplate — collapsing the disc height that the surgery was meant to restore and eliminating the lordosis correction that protects the adjacent levels. A cage that is placed at the wrong angle leaves the fused segment straight or slightly kyphotic rather than curved inward, redistributing mechanical stress to the levels above and below and accelerating their degeneration.
The surgeon who measures the disc space from standing imaging, calculates the target lordotic angle from the patient’s individual pelvic incidence, and selects the cage accordingly is making a fundamentally different decision than the surgeon who opens the implant tray and selects the cage that “looks about right” once they are in the disc space. Both will write “lumbar interbody fusion” on the operative report. The outcomes at ten years may not resemble each other at all.
In this practice, every surgical candidate receives a full-body standing EOS X-ray before any fusion is planned. The software measures every spinopelvic parameter automatically — pelvic incidence, lumbar lordosis at each level, sagittal vertical axis. The cage is then selected to match the calculated target for that patient’s individual anatomy. The implant is chosen for the patient. Not the patient fitted to the implant.
Screw placement — millimeters determine decades
Pedicle screws anchor a spinal fusion construct to the vertebral bodies. Where they enter — specifically, how close they come to the facet joint at the top of the construct — has direct consequences for how long the fusion remains isolated before adjacent segment degeneration sets in.
The facet joint immediately above the top screw is the last remaining motion segment above the fusion. If the top screw violates that facet — encroaches into the joint capsule, damages the cartilage, disrupts the joint architecture — that joint is injured at the moment of surgery. It will degenerate faster. Adjacent segment disease will arrive sooner. The patient will be back in a surgeon’s office sooner.
Percutaneous pedicle screws, placed under fluoroscopic or navigated guidance with explicit intent to position them lateral to the adjacent facet joint, achieve low violation rates when that is the surgeon’s deliberate goal. Open pedicle screw placement, particularly with a freehand technique in a large open exposure, consistently shows higher violation rates in the published literature. The technique is not the variable. The intention is. A surgeon who has not thought carefully about this will not be aiming for it.
“A millimeter of screw trajectory separates a facet joint that functions for twenty years from one that fails in five. That millimeter is entirely a function of surgical philosophy and precision — not luck.”
Symmetry and balance — the spine as a structural system
The human spine is not a collection of independent levels. It is an integrated mechanical system where every segment affects every other segment. The curve of the lumbar spine — its lordosis — is not decorative. It is load-bearing. It allows the body to carry the weight of the head and trunk with minimal muscular effort by distributing forces efficiently through the vertebral column. When that curve is disrupted at any level — by a flat cage, a poorly positioned implant, or a fusion that ignores the overall alignment — the system compensates. Adjacent levels move more. Muscles work harder. Discs degenerate faster. Pain follows.
The concept of sagittal balance — the alignment of the spine and pelvis in the standing position — is the framework surgeons use to think about this. Every person has a pelvic incidence, a fixed bony measurement that determines exactly how much lumbar lordosis their spine requires to be mechanically balanced. It does not change after adolescence. It is measured, not estimated. A patient whose lumbar lordosis after fusion matches their pelvic incidence requirement will have a balanced spine. A patient whose fusion leaves them with a PI-LL mismatch — whose lordosis is insufficient for their pelvis — will have a spine under abnormal stress from the day they leave the operating room.
Some surgeons do not measure this. Some do not believe it matters. The literature suggests it matters considerably — PI-LL mismatch of more than 10 degrees is one of the strongest predictors of symptomatic adjacent segment disease after lumbar fusion. The measurement takes minutes. The consequence of not taking it lasts years.
A properly planned lumbar fusion is not a structural repair of a single level. It is an architectural intervention in a load-bearing system. The fused segment must be restored to the correct height to re-establish disc space dimensions. It must be positioned at the correct angle to contribute the right amount of lordosis to the overall lumbar curve. The cage must be sized to sit on the strongest part of the endplate — the cortical rim — not the weak central zone. The screws must be positioned to preserve the adjacent facet joint. And the overall alignment must match the patient’s pelvic parameters so the spine is balanced when the patient stands up and walks out of the recovery room. Every one of these decisions is made before the first incision, not during it.
The tools that enable precision —
technology in service of judgment, not a substitute for it
Modern spine surgery has tools available that would have been unimaginable a generation ago. Used correctly, they extend the precision of what a skilled surgeon can achieve. Used as a substitute for surgical judgment, they are expensive and ineffective.
EOS full-body standing radiography captures the entire spine, pelvis, and lower extremities simultaneously in a true weight-bearing position, with automated measurement of every spinopelvic parameter. It gives the surgeon a precise, quantitative picture of the patient’s alignment before any surgical plan is formed. The standing image is the clinically relevant one — a spine that looks acceptable lying down on an MRI table may be significantly imbalanced when the patient is upright and gravity is applied.
Robotic navigation allows pedicle screws to be placed with sub-millimeter accuracy relative to a pre-operative plan. The robot does not decide where the screws go. The surgeon decides — informed by the pre-operative imaging and the explicit goal of preserving the adjacent facet joint — and the robot executes that plan with precision that exceeds what freehand fluoroscopic technique can reliably achieve.
Intraoperative neuromonitoring provides real-time feedback on the functional status of the nerve roots and spinal cord during the most critical moments of the decompression and instrumentation. It does not make the surgeon more skilled. It provides an early warning system that allows a skilled surgeon to identify and correct a problem before it becomes irreversible.
Ultrasonic bone scalpels — the Stryker Sonopet and Masonix BoneScalpel — cut bone through oscillatory vibration rather than the spinning motion of a high-speed drill. When the bone being removed is immediately adjacent to a compressed dura and nerve root, the non-rotating mechanism substantially reduces the risk of inadvertent contact with soft tissue. The tool does not improve judgment. It reduces the consequence of the geometry being tight.
None of these technologies produce good outcomes in the absence of surgical judgment. They are amplifiers. They make precise surgeons more precise. They cannot replace a surgeon who has not thought carefully about what the patient needs and why.
“The robot does not decide where the screws go. The surgeon decides. The robot executes that decision with accuracy that exceeds what the human hand can reliably achieve alone. Judgment first. Technology second.”
The minimally invasive philosophy —
respect for what you did not cut
Minimally invasive spine surgery is often described in terms of what it removes: smaller incisions, less blood loss, shorter hospital stays. These are real advantages. But they miss the deeper principle.
The minimally invasive philosophy is fundamentally about respect for the anatomy that does not need to be disturbed. Every structure that is cut, stripped, devascularised, or retracted unnecessarily is a structure that now has to heal, and a structure whose healing may be incomplete. The paraspinal muscles stripped from the spine in an open lumbar surgery are not just painful during recovery — they are muscles that stabilise the spine, and their long-term function after extensive stripping may be permanently diminished. The facet joints violated by carelessly placed screws are not just a source of postoperative pain — they are joints that were functioning before surgery and now are not.
The 18mm tubular retractor that defines the MIS approach does not simply make a smaller skin incision. It accesses the spine by spreading the paraspinal muscles along their natural tissue planes, without cutting them or stripping them from their bony attachments. When the tube is removed, the muscles return to position. They were never cut. They do not need to heal from the surgery — because they were not injured by it. The spine that was operated on is intact structurally, with the target pathology addressed and nothing else disturbed.
This is not a marketing claim. It is a structural philosophy. The question asked before every surgical decision is not just “how do I address the problem?” It is “how do I address the problem while disturbing as little of what is working as possible?” Those are different questions. They produce different operations.
The meaningful measure of minimally invasive surgery is not the size of the skin incision. It is the difference between what the spine looked like before surgery and what it looks like when the operation is complete. A spine that has been decompressed with an 18mm tube, muscles intact, adjacent joints undisturbed, and alignment restored to its individually calculated target is a minimally invasive result — regardless of which approach the surgeon used to achieve it. The goal is to fix the specific problem and leave everything else exactly as it was.
What to ask —
the questions that reveal whether a surgeon thinks this way
Most surgical consultations are structured around the procedure: what it is, what the recovery looks like, what the risks are. These are important questions. But they do not reveal whether the surgeon has thought carefully about the craft of the operation. The questions that reveal surgical philosophy are different.
“How do you select the size and angle of the cage for my specific anatomy?” A surgeon who has thought carefully about this will describe a pre-operative measurement process — standing imaging, pelvic incidence calculation, target lordosis selection. A surgeon who has not will give you a general answer about using the right size for the space.
“Where do you position your top screws relative to the adjacent facet joint?” A surgeon who has thought about adjacent segment disease will describe deliberate lateral positioning and how they verify placement. A surgeon who has not will not have a specific answer.
“What does my sagittal balance look like, and how does it affect your surgical plan?” This question requires familiarity with spinopelvic parameters, pelvic incidence, and lordosis planning. Most patients have never been shown their sagittal balance. A surgeon who has evaluated it will be able to show you and explain it. A surgeon who has not will not know what you are asking.
“What will you do to preserve the anatomy that does not need to be addressed?” The answer to this question reveals whether the surgeon thinks of the operation as a targeted intervention in a functioning system, or as a repair of the identified problem with everything else being incidental.
Yes. More than almost any other variable in your treatment. The procedure is a framework. Within that framework, the surgeon makes hundreds of decisions that determine whether your ten-year outcome resembles the best published results or the worst. Those decisions are not visible on the consent form. They are not captured in the operative report. They exist entirely in the judgment, philosophy, and technical precision of the individual surgeon — formed over years of training, refined over hundreds of cases, and expressed in the specific choices made in the operating room for your specific anatomy on the day of your surgery. The procedure is a commodity. The execution is not.
Why I think about surgery
the way I do
I trained at the Barrow Neurological Institute under surgeons who thought about spine surgery this way. The expectation was not that you performed the procedure competently. The expectation was that you understood the biomechanical consequences of every decision you made — why this screw trajectory rather than that one, why this cage angle rather than a flatter one, why this level of decompression rather than a wider one — and that you could articulate the reasoning.
That foundation shaped how I approach every case. Before each operation, the imaging is reviewed with specific questions: What is this patient’s pelvic incidence? What lordosis does the fused segment need to contribute? What size cage achieves that, and what is the largest footprint that fits this endplate? Where are the adjacent facet joints, and how do I ensure the top screw does not encroach on them? What does the dura look like at the target level, and is there anything on the CT that suggests calcification or OPLL that would change my instrument selection?
These questions are asked before the operation begins because the answers determine the operation. You cannot make good intraoperative decisions without having thought carefully about them preoperatively. The operation itself is the execution of a plan — not the formation of one.
This is what I mean when I say spine surgery is as much art as science. The science tells you what the procedure is, what the anatomy is, and what the published outcomes are. The art is the judgment applied within that framework — the precise, patient-specific decisions that transform a procedure into an outcome. The science is teachable. The art is developed.
for your specific anatomy?
Upload your imaging before the consultation. Dr. Katsevman reviews everything personally and walks you through the specific decisions that would be made for your anatomy — cage selection, screw trajectory, lordosis target, alignment goals. The consultation is a conversation about your spine, not a presentation of a standard procedure. Naples and Fort Myers offices. Telemedicine available.
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