3D technology in orthopedic and trauma surgery
In this editorial, Orthopedic Surgeons Fernando Menor Fusaro and Pierluigi Di Felice Ardente (both Althaia Hospital; Barcelona, Spain) discuss how their team has adopted 3D technologies in orthopedic and trauma surgical workflows.
Fernando Menor Fusaro
Consultant Orthopedic Surgeon, Knee and Shoulder Specialist at Althaia Hospital (Barcelona, Spain)
Pierluigi Di Felice Ardente
Consultant Orthopedic Surgeon, Shoulder and Sport Medicine Specialist at Althaia Hospital
The advent of radiographic techniques heralded a revolution in the medical world. Physicians were able to look at what was going on inside their patients’ body and therefore come up with more informed diagnoses and more effective treatments. Naturally, the introduction of radiology into hospitals required a significant adaptation process, which involved learning to interpret images, developing new techniques that built on the advantages of radiography and accepting the cost increases associated to the purchase of new equipment and the hiring of the technicians needed to operate it.
In the face of such a significant revolution, it is not uncommon for people to react negatively and try to resist change. Many physicians were probably unable to understand the advantages offered by the new technologies and their patients suffered the consequences."
Many years after the advent of radiography, we now seem to be facing a similar disruption. The development of 3D image processing, compounded with the widespread use of volumetric modeling software and the emergence of additive manufacturing, have paved the way for the introduction of new methods to improve outcomes in orthopedic and trauma surgery. Nowadays, we physicians are not only able to look at what goes on in our patients’ bodies, but can do so in all three spatial dimensions, moving in any direction we may choose in order to plan our surgical strategy. We may even construct a physical model to rehearse our surgical maneuvers before we walk into the operating room. Moreover, some manufacturers sell custom implants that are fully adapted to individual patient’s characteristics.
A world full of fantastic opportunities opens up before us but, at the same time, it is imperative that we adapt to the new times and seek the proper training to make the most of the benefits offered by the new technologies."
The purpose of this editorial is to share with our colleagues the way in which our unit has adapted to a set of new working methods, with a view to offering them some guidance for their own adaptation process.
The cornerstone in our method of work is training. Every new resident that joins our unit must follow an instructional program whereby, amongst other things, they learn to use analytical tools and to carry out 3D modeling and printing. This usually poses quite a significant challenge for both instructors and trainees as medical training as imparted in medical school has more often than not neglected the new technologies, which means that newcomers to our unit do not possess any previous knowledge on the subject. It is important to start by the most basic concepts but without losing sight of the fact that our ultimate goal is to encourage application of the acquired knowledge. For that reason, we lay special emphasis on the study of real-life cases and on how preoperative planning and the use of modeling tools may improve clinical outcomes. Trainees must be made aware of the practical application of what they are learning. Otherwise, they will never consolidate the contents acquired, let alone put them into practice, which would turn the whole process into a huge waste of time.
Our clinical sessions provide trainees with an opportunity to analyze computerized axial tomography images, using computers that allow them to scan those images. Team members are encouraged to plan for their procedures using all the tools available to them. All the members of the unit can therefore give their opinion on the different cases drawing on as much information as possible.
This process requires a greater effort to be made when presenting each case, but it allows for a greater amount of knowledge to be conveyed to the team and affords better clinical outcomes."
But what indications are amenable to these new technologies? In our opinion, they may be used in a virtually unlimited number of indications. One of the most straightforward ones is the visualization of pathological bony geometries in fractures or angular deformities. On some occasions, the information provided by a radiograph is incomplete or difficult to interpret. Our unit specializes in the upper limb, and the shoulder and the elbow joints are anatomical areas where the superimposition of layers of bone tissue makes diagnosis and decision-making difficult in the presence of anatomical abnormalities. A CT-scan allows trauma surgeons so detect hidden fracture lines or overlooked dislocations and to visualize the arrangement of the different bone fragments of a fractured joint. Visualization software makes it possible to virtually ‘navigate’ the bone and even get into small bone crevices in an attempt to better understand the problem facing the patient we intend to treat. It is much more difficult to overlook uncommon or difficult-to-interpret lesions such as a subluxation, a bone fissure or a chondral lesion. This kind of easy-to-use software can be managed by the trauma surgeon without the assistance of a radiologist. Until now, the trauma surgeon issued his diagnosis on the basis of a ‘static’ report drawn up by the radiologist. Now, the trauma surgeon can sit in front of his computer and analyze the information in a ‘dynamic’ way, looking at the images from different perspectives and navigating the 3D model to look for the most relevant images.
The second stage in the process centers on the introduction of the segmentation software, which is used to divide or segment the information provided by the CT-scan. It is therefore possible to move a group of bone segments or fragments with respect to others in order to ‘simulate’ the surgical process. This means that the surgeon can simulate the surgical procedure on his computer screen. This is particularly useful in multi-fragment fractures, where surgeons invariably have doubts as to what approach to choose, which segments should be fixed and which should be left unattached as they would not withstand any fixation whatsoever.
What’s more, some manufacturers have released 3D models of their implants, which can be incorporated to the simulation, providing the healthcare practitioner an accurate idea of the final outcome of the surgical reconstruction.
In our unit, we took our first steps along the way with clavicle fractures. The advantages became apparent from the outset: less operating room time, simpler surgery and optimization of cost and materials. Furthermore, intraoperative use of a C-arm is no longer required, which reduces the levels of radiation received by the patient and the medical team. This methodology allows us to approach a clavicle fracture knowing right from the start what type of plate will be used, what screw lengths will be necessary and the exact final position of every single element thanks to the anatomical landmarks previously marked in the 3D analysis.
We gradually expanded our expertise to other types of fractures or conditions, such as proximal humerus fractures and dislocations, tibial pilon fractures, knee osteotomies or shoulder replacement surgery.
3D modeling opens up a world of possibilities."
As mentioned at the beginning of the present editorial, manufacturers produce custom implants based on the patient’s CT-scans and the indications of the attending surgeon. The involvement of engineers is crucial to guarantee that the implants will withstand the mechanical loads they will be subjected to. In addition, manufacturing methods must comply with all relevant legal and technical specifications. If necessary, trauma surgeons may develop specific instruments and jigs to facilitate the surgical procedure. In our unit, we have developed custom jigs aimed at optimizing glenoid orientation in patients undergoing reverse shoulder arthroplasty. Correct positioning of the glenoid component is probably the most challenging technical step in any RSA. Indeed, the approach used tends to limit visualization of the glenoid, which makes life very difficult for the surgeon, who is expected to implant the prosthesis in the right place with very few anatomical landmarks to go by. 3D modeling and printing make it possible to design and print custom jigs made of medical grade resin for each patient. Such jigs help us orient the glenoid in accordance with our computer-based preoperative plan, which reduces operating room time and improves clinical outcomes.
The usefulness of new technologies extends throughout the clinical cycle, from initial diagnosis through decision-making to final treatment."
For example, in a report pending publication, CT images allowed our team to diagnose a humeral dislocation that had gone unnoticed on plain radiograph inspection. We were also able to identify a bone lesion that was associated to that dislocation and designed a series of specific jigs to smooth out the bone edges, preserving as much bone as possible. We also developed a series of jigs that we use intraoperatively to shape an allograft to a matching defect. All of this allowed us to obtain excellent results and high patient satisfaction scores.
New imaging techniques, together with 3D modeling and printing provide trauma surgeons with a wealth of different operative possibilities."
Needless to say, they also require appropriate training and a willingness to adapt to new working methods. The economic cost hospitals have to bear is relatively low on account of the new software licenses and the spread of additive printers. The 3D revolution has taken the medical world by storm. And it is here to stay.
Note: We would like to thank María Rabanal and Pablo Roza for their assistance in drafting the present editorial.
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