Spine fusion technology compels both experienced and novice surgeons to re-explore fundamental technique. Placed together as a team, each learns from the other, thereby creating new methods
Mr Robert Lange
Composite Implant Developer,
Dr med Daniel May
Hôpital de La Tour, Meyrin, Switzerland
Dr med Patrick Moulin
Schweizer Paraplegiker-Zentrum, Nottwil, Switzerland
Dr med Thomas-Marc Markwalder
Klinik Beau-Site, Bern, Switzerland
New technology comes to spinal surgery with the hope of improving performance. Fascinating in itself, technology is placed upon hospital websites and in brochures. It represents skill and competence in a form that the patient understands. But will technology change the surgeon’s need to develop manual expertise or eliminate spine fusion surgery as a hands-on craft and art?
Not likely, or at least not until spinal surgeons stop holding instruments and touching patients with their hands. With each new empowerment that technology brings, a problem emerges, with its reciprocal opportunity. Novice and expert return to explore anatomy and technique they have learned before. It is hands-on, at times uncomfortable and awkward. Sometimes it is illuminating. New treatments are perceived along with new methods for fusion surgery training. This is not just equipment operation, also a challenge, but learning to navigate in a changing landscape that technology provides.
Computer assisted surgery: more to understand and use
For example, when two vertebras are fused together using spinal implants as stabilisation, it could seem that navigation systems would replace the surgeon’s need for tactile performance. But the opposite is so.
Also called computer assisted surgery (CAS), spinal navigation systems are used to aim, to guide, and to depth measure the trajectory of a pedicle screw into a vertebra. Pedicle screws are the bone anchors that the surgeon implants to build a fusion stabilisation construct. In real time surgery, everyone sees the virtual screw moving across a projected CT image of the vertebra. Some studies show that CAS improves pedicle screw placement accuracy, and helps detect errors, which is reassuring for the surgeon, but that hand verification with a ball tipped instrument was still more precise.(1) Surgeons therefore use both.(2) The CAS manufacturers also caution: “The system and its associated applications should be used only as an adjunct for surgical guidance. They are not a replacement for the surgeon’s knowledge, expertise, or judgment.”(3) (Read: ability to infer from anatomical landmarks what is not detected and to have the hand–eye coordination to use this.)
Dr Craig Humphreys, who uses this technology, said in an interview, “despite the advances, the technology doesn’t replace a good pair of steady hands. You’ve still got to be smarter than the robot or at least understand what the robot is doing.”(4)
The rest of the intervention
There is a lot to be smart about in spine fusion surgery. Pedicle screw insertion is a routine, immensely important, and somewhat dangerous, event; but not the whole operation. Vessels, ligaments, muscles and scar tissue must be identified and managed. Each structure can be used to guide the surgeon’s safe passage up to the pathology to be treated, for example, a compressed nerve within the spinal canal. Furthermore, surgeons use their ears and hands to converse with things unseen.
There is the strength of vertebral bone, its sound when scraped or tapped, and the texture of a connecting ligament, all of which tell surgeons how to regulate a gesture for each patient. Such skills are supposed to be part of the surgeon’s toolbox from basic training. But navigation technology provides more information and new angles of approach, and which change the visualisation of a once-familiar topography. It can become less understandable. Imagine walking backwards, through a familiar office. Recognisable. Disorienting. Can be dangerous.
It is rare, but as lost terrestrial travellers using GPS also know, computer navigation systems can shut down or provide false information. In a spinal fusion intervention, this event leaves surgeons alone with their patient and the medical knowledge they brought to the table.
In an ideal world, new vantage points and equipment should be experienced physically, in a safe environment.
The theatre nurse’s lack of view
The assisting theatre nurse strives from a distance to see and keep up. The goal is to anticipate each surgical manoeuvre, and find and deliver the right instrument, ideally like a dance that meets the surgeon’s rhythm. Situational awareness should extend from metal tools out to human tissue, knowing what is being performed, where and how. To anticipate is to know the movement. That is to understand, partially see and then imagine the rest. Surgical incisions are shrinking to reduce patient trauma. Visualisation can be poor. The microscope and endoscope help, but not always. The nurse too should know the tactile information that the surgeon feels in order to better understand and assist. For each new procedure, this should be reviewed.
ostaPek carbon composite
Newer biomaterials deliver new performance to spinal implant constructs. But in the same thrust, they impose subtleties upon the hands of the operative team. For example, ostaPek carbon composite brings radiolucent and elastic stabilisation to the longitudinal elements of a spine fusion implant. Surgeons connect composite rods to pedicle screws and this is changing how they treat adult degenerative deformity and spinal tumours. Recently, carbon composite is being used to build long fusion constructs that span many levels of the spine for a more elastic stabilisation. But, in a complex surgery, composite behaves with more spring, which in the surgical wound creates a different expression than metal or plastic.(5) It startles, yet is part of the treatment in the hope of stimulating bone growth and absorbing shock to the spine to be fused. The surgeon’s original skills must adjust to exploit carbon composite’s properties in treatment.
The problem with doing it right every time
It should be mentioned that other elements can prevent progress and even degrade basic skills: the tyranny of habit and routine. Deployed each day to protect the patient, the virtues that form safe habits can also forbid considering something new. The resulting routine, when combined with some technologies, can gradually nudge surgeons away from basic skills that become unused only to be abruptly needed in a new situation that technology creates.
Pilots have learned this in tragedy. Landmark accident investigations found that some procedures created a gradual over-reliance on technology that induced otherwise good pilots to ignore warnings and to misinterpret an emergency. Furthermore, if automation systems brought more safety overall, they prevented regular use of manual skills taught in early months of training that were fatally absent in a new type of emergency.(6) These findings have lead aviation to ponder how to not only train pilots to manage complex systems, but to ensure their hands on flying does not erode when using new this technology.(7)
Performing spine fusion surgery on humans is not flying a machine, but pilots provide surgeons with a take-home message. As technology delivers safety, as it empowers, it creates new situations that requires us to review and repeat skills from basic training that must always be present and kept ready for a new situation.
In search of a high technology simulator
Most surgeons seek recurrent training in order to keep up and learn new techniques.
Surgery-specific plastic models, sometimes called sawbones, enable surgeons to experience the spatial relationship between the vertebra, the implants and the bony decompression. Instruments can be felt in sequence. But the muscles, ligaments, nerves and scar, if represented, are rudimentary at best. Plastic models do not represent the aspect or feel of surgery.
Medical literature, books, and the Internet show best practice. But for surgeons wishing to perform a new fusion procedure, these can be somewhat like watching a film of a professional golfer hit the ball. Informative. Inspirational. Leaving individuals confronted with their own need for execution.
The spine surgery team looks elsewhere.
Two perspectives from the garden
It began with a discussion in a garden, now 20 years ago, from two perspectives: medicine and industry. It is remembered this way. The first, a respected, experienced, and most technologically endowed spinal surgeon said “the work was changing so quickly, even the universities cannot keep things in their curriculum, where can they practice what is new? And what about the experienced surgeon who has left the university? They are not seeing what I am.
Or am I missing what they are seeing?” The second, an implant designer and manufacturer remarked, “we have moved to carbon composite with its new performance, but its handling can be a surprise. How can we get others to review and experience what would at first seems basic, but is essential to operator’s working with new materials?” The coAlliance composite Surgeons’ Workshop was born.
The human cadaver, with its complex history in society, remains the most modern of simulators for spine surgical technique.(8) There are some specialists who claim they can see who regularly performs dissection, by their elegance in managing tissues, by the breadth of techniques used to adapt to each patient.
Therefore, for composite spine surgery training, traditional cadaver sessions were chosen, but with a twist. Teachers are selected on competence and their experience with an intervention, not on the basis of age. The expert teachers of one technique would, in the same workshop, become students at the tables exploring another for which they were less familiar and comfortable.
This adjustment came from flight schools where instructing pilots routinely teach from the right seat next to another experienced colleague in the left seat, who is learning a manoeuvre or honing a skill. The session’s instructor on the right might be junior in age to the ‘student’ on the left, who is otherwise an expert pilot. In an airplane, poor lessons can be lethal for both, so this regular practice of role change builds mutual respect, trust, as well as competence.
From mentor to student, and back
The coAlliance Composite Spine Surgeons’ Workshop provides experience in several surgical fusion implant techniques. Each method represents a surgical strategy for treatment that might be competitive with the other to be used to address the same problem. Few in the faculty practice all methods, so most are both expert and novice at something. Attendees range from a newly trained spinal surgeon to expert, spanning several decades of age and experience. On arrival, basic technique and theory is presented, closing with a ‘what might you do?’ case discussion.
From a small group that represents different generations, nationalities and training, these discussions can be almost combative because there are many ‘best practices’ for any problem in spine. Surgeons, after all, must bring clear convictions into the operating room in order to perform. Opinions are expressed.
The following day, after a good reconciliatory meal, participants are placed into groups. An expert, usually with a few thousand cases of a particular method, presents, while at several dissection tables, a team of students and their leader follow. Each table deliberately comprises expert and novice, where age is not the criteria, but experience in the method. After one technique is performed, the experts in the first technique move to another table to perform a second, less familiar, technique.
Surgeons newer to spine are surprised to see that the ‘expert,’ who so elegantly presented the anterior approach before, will, just like them, stumble in a far lateral approach. The experienced, and even the faculty, might find themselves learning a new technique from someone 20 years younger, even perhaps someone they had taught before. They are no longer subordinate and chief in a medical hierarchy, but craftspeople that stand on an equal ground.
Theatre nurses enthusiastically joined the coAlliance Composite Spine Surgeons’ Workshop several years ago and are asked to perform spinal fusions as if they are surgeons. Under surgeon guidance, they are shown to make the approach, decompress the spinal canal, place interbody fusion cages, and close the wound.
Nurse and operating room chief, Marie Humbert, came to the course to evaluate if it would be useful for her team of theatre nurses. She discovered that in spite of her years of experience, “There were many simple things I did not know.” She also stated: “Without the stress of a surgery, it was very instructive to be shown how to actually use the instrument by a surgeon.” It changed her understanding.
Estelle Donguy, who assists spine fusion surgeons several times each week said, “from the instrument table, I could not realise they were working so deep.”
“I also see that my moments of high-level concentration in a case can be different than my surgeon’s moments of high-level concentration. This helped me”, she said.
Industry implant developers
The health care professionals who design, supply and organise the coAlliance workshop also participate and perform simulated surgeries. They experience that it is one thing to watch surgery and another to attempt to do the same with an expert. For the system designer, conceiving implant systems can be like trying to improve an engine without ever being able to see under the hood. “We have to make this thing simpler,” commented Jakob Funnemark, a composite implant developer.
As the day moves on, and different teams perform different methods, the unspoken subtext of the collective attitude changes from ‘look at me,’ to become ‘say, how do you do this?’ At times nurses show surgeons how they have seen others hold an instrument and ask why, only to later see the technique adapted. There are moments when professors, without the pressures to provide expedient treatment for their patient, physically guide an assistant’s hands through manoeuvres that are routinely seen but not performed by the other. New ideas are considered. Old ones refined. No one leaves unchanged.
Skeptics legitimately state that dissection courses are not unique, that these are industry sponsored and therefore not objective. The mercantile interests of the organiser might prevent them from providing participants the ‘full’ story. Furthermore, some ‘improvements’ are so minor, that the impact on treatment cannot be objectively measured. Yet 20 years on, coAlliance workshops are over-booked. For the participants, at least, the benefit of the experience seems to outweigh these concerns. Everyone, at all levels in the workshop, must perform and explore in the company of another. Frustration and inspiration are not hidden, but rather shared in a place where it can be explored.
Dr Pawel Baranowski, coAlliance faculty, head of a spine department and teacher in many other programmes said it this way: “People ask me, ‘why have you returned to the same course for 10 years?’ Because I learn something new every time. I am 60. When you stop learning, you start to fade. Today I did something I have never tried. Using our far lateral technique, from the near side you can reach around the spinal cord to opposite far side of the spinal canal and then decompress stenosis. Normally I would make a larger access. This is not in the textbooks. I will probably use it next week,” said Dr Baranowski.
A silent pact
Spinal fusions are performed in an operating theater. The semantics should strike us. Surgery has always been and probably will always be a performance art. The patient comes to their surgery eyes open. In their consent to be put to sleep, the patient seals a pact with the surgical team to engage their most sincere determination and best ability for treatment. Technology is both its representation and means. Industry supplies this, but technology is not enough alone. It compels everyone to explore spinal fusions in their most basic details. Safely. This is handwork, to be done in a place of curiosity, exploration and trust. It is the reinvention of spinal surgery.
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