3D printing is already being used to create customised orthopaedic implants for joint replacement surgery. Now, further technological advances are offering a glimpse into the future of orthopaedics whereby synthetic implants could be populated with a patient’s own cells to encourage tissue regeneration.
Researchers at Newcastle University are working on a new technique called 3D bioprinting that will allow customised implants to be created using 3D printing and then combined with a cell-filled gel that will encourage the patient’s own tissues to regenerate after surgery.
The benefit of this will likely be quicker recovery and more successful joint replacement surgery.
3D printing in orthopaedics
Unlike traditional printing which involves laying down an image onto a flat surface, 3D printing deposits materials – plastic, metal, ceramic, powders, liquids or even living cells – in layers to create a three-dimensional object. It allows orthopaedic surgeons to print artificial bone using a scan of the patient’s body as a template. This means that synthetic implants can be personalised to the individual to produce better results.
The disadvantage of conventional joint replacement surgery using ready-made implants is that surgeons have to compromises on the precise fit and sizing of the implant, choosing the one that most closely matches a patient’s bone structure.
If an implant does not fit perfectly and replicate closely the patients own anatomy, it can lead to long-term pain and restricted mobility. One in five people who receive an off the shelf knee implant, for example, are not fully satisfied with the results of surgery.
Benefits of 3D printing
Using 3D printing, it is possible to create an implant that is a perfect, customised fit. The implant mimics the natural shape of the patient’s joint, resulting in less pain and improved mobility. 3D printing could be used in the treatment of many different medical conditions, from bone cancer to hearing loss.
Already people have received pelvic implants for bone cancer and in bone loss after worn out or infected hip replacements, skull implants for head trauma and replacement heel bones using the technique. In the future, it is likely that 3D printing will be combined with stem cell research to print living bone cells or functioning organs for transplant using the patient’s own cells.
Reactive Jet Impingement
In the meantime, a 3D bioprinting process called Reactive Jet Impingement (Reji) has been developed as part of the MeDe Innovation programme by researchers at Newcastle University. Cells from the patient’s own body are combined with a gel and deposited onto the synthetic implant. This creates a gel-filled layer between the implant and the patient’s own tissue, mimicking native tissue and helping to encourage the growth of new cells to speed recovery.
The Reji technique involves jetting droplets of gel precursors at one another which react in mid-air and drop onto the substrate. This is faster than other approaches using a syringe or extrusion-based approach and the lower pressures needed allows a greater number of viable cells in the final product. The team has experimented with creating different cell-filled gels, such as fibrin, alginate and hybrid collagen cells. All were found to have high viability.
Support cushioning and integration
They also produced gels of varying stiffness, with some more suitable for providing cushioning while others show encouraging results in terms of supporting the integration of a new orthopaedic implant.
The team has filed a patent application for the Reji technology as the first stage towards commercialising the process.
As well as being used for treating musculoskeletal disease and injury, the process of printing cell cultures opens us new possibilities in drug testing and disease modelling. With funding from the National Centre for the Replacement, Refinement and Reduction of Animals in Research, the team has begun a collaboration to develop new drugs for osteoarthritis without the need for animal testing.
Read more about 3D printing in orthopaedic surgery.
Specialists in hip, knee and pelvis surgery | Cambridge
Mr Andrew Carrothers specialises in hip, knee and pelvis surgery to treat arthritis, and injuries.
Subsequently, advances in technology that allows patients to recover quicker and with greater comfort for their joint replacement, is fundamental for our ongoing work as orthopaedic surgeons.
At Carrothers Orthopaedics we are always striving towards exceeding patients expectations and excellent treatment outcomes.