3D Printing: A New Deal for Surgical Planning
The rise of 3D printing represents a huge advance in surgical planning by improving our understanding of anatomy. One London hospital to recognize the potential of this promising technology is Charing Cross, which has an active surgical research laboratory.
James Duncan, clinical research fellow and the rest of the orthopaedic surgery team were faced with a tricky procedure: thereconstruction of an acetabular – or pelvic – fracture in a man who had had a motorbike accident. These fractures, mainly associated with extreme trauma, are extremely complex. Thus, in the preoperative planning stage and during the operation itself,surgeons usually rely on computed tomography images in conjunction with plain X-rays to work out how to repair them.
The main drawback to the widespread adoption of 3D printing is cost.
“The pelvic surgeon commonly has a CT scan on a screen and looks at a rotating image. What the pelvic surgeon is doing is very complex compared to other orthopaedic procedures. They rely on X-rays during the operation but it’s difficult to really know what you’re actually looking at,” Duncan told MedicalExpo.
The surgeon, who is now based at King’s College Hospital in a different part of London, explained that this method is not perfect, as it can be difficult to determine where to put all the individual plates and screws.
Printing a 3D Model of the Pelvis to Work On
So the team came up with the idea of printing a 3D model of the patient’s pelvis – based on detailed CT scans – to give the surgeons a more accurate version to work on. The tangible nature of an actual 3D model helps the surgeons to visualize the bonehe or she is going to operate on and to work out more accurately the best way to approach the fracture. Duncan explained:
By having a 3D print of that individual patient’s pelvis in theatre with you, you can look at the print which will help you to appreciate the patient’s anatomy and will help you with screw and plate positioning.
To create the model, conventional CT scans were used and the files were then converted into a format so that they were compatible with the 3D printer. They were printed on an Objet Eden 250 printer utilising selective laser sintering – a standard 3D printing process – of nylon.
Saving Time and Money
Having a 3D model to examine before the operation has the potential to save time and money, according to Duncan. Although he said that it is difficult to put a number on the amount of time saved.
Having the model to look at reduces the amount of time the patient is being operated on. This is better for the patient as they need less anaesthetic and it also reduces the risk of blood loss and can aid recovery time.
For the moment, the application of 3D printing is still in its infancy. Duncan said:
In reality, 3D printing isn’t being used widely at all at the moment, and the vast majority of hospitals wouldn’t have the facilities to be able to use the technology.
The main drawback to the widespread adoption of 3D printing is cost – hospitals are unlikely to invest in 3D printing when at present there is little hard research evidence of its effectiveness, both clinically and financially. “You could argue that pelvic surgeons manage perfectly well without 3D printed models, however if they reduce complication rates and surgical time, then overall they will actually save money.”
3D Printing Used in Maxillo-Facial and Heart Surgeries
Other specialties pioneering the use of 3D printing are maxillo-facial surgery – where it has been used to create models forsurgeons planning face transplants – and in cardiac surgery. Surgeons at St Thomas’ Hospital in London created a 3D model of a two-year-old girl’s heart earlier this year to allow them to work out the precise dimensions of the hole in her heart, prior to repairing it surgically.
The main next step within orthopaedics will be the widespread use of customized implants such as hip and knee replacements, explained Duncan, adding there is great interest in the technology from orthopaedic surgeons.
I think it is more likely that 3D printed custom implants will soon become commonplace in private practice and that it will grow there for a few years until the technology is cheaper and more available.