Bone structures...
An adult has 206 bones in their body that are made up of connective tissue reinforced with calcium and specialised bone cells. Bones are consistently remodeling the body by building up new bone tissue and breaking down old bone tissue. (Coraggio 2015)
Picture: (2010, accessed October 26, 2016, from <https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/bones>.)
Common methods of fixing bone issues
A bone graft is a surgical procedure, which involves the transplantation of bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones. Hips, Knees, and spine are the most common examples of bones repaired using this procedure. However bone grafts also used to repair other bones, joints and bone loss caused by some fractures and cancers. The body must accept the bone graft in order to provide a framework for growth of new, living bone.
The bone used in bone graft is acquired from the body of the patient , or a donor. Doctors will test the donor bone also known as the allograft, in order to make sure is safe to use. Bone graft acquired from the patient himself is is called autograft and it generally comes from the ribs, hips or legs.
Unfortunately however a bone Graft operation has its downfalls. Firstly all surgical procedures involve the following. Risks of bleeding, infection, and negative reactions to anesthesia. The operations can also cause; pain, swelling, nerve injury, inflammation, reabsorption of the graft, and rejection of the bone graft, Secondly for the operation to take place a new piece of bone must be located. Either an Autograft or an Allograft will be required, Autografts require an additional procedure, while Allografts increase the risk of the body rejecting the new piece. In either case, the amount of bone that can be used is limited.
The bone used in bone graft is acquired from the body of the patient , or a donor. Doctors will test the donor bone also known as the allograft, in order to make sure is safe to use. Bone graft acquired from the patient himself is is called autograft and it generally comes from the ribs, hips or legs.
Unfortunately however a bone Graft operation has its downfalls. Firstly all surgical procedures involve the following. Risks of bleeding, infection, and negative reactions to anesthesia. The operations can also cause; pain, swelling, nerve injury, inflammation, reabsorption of the graft, and rejection of the bone graft, Secondly for the operation to take place a new piece of bone must be located. Either an Autograft or an Allograft will be required, Autografts require an additional procedure, while Allografts increase the risk of the body rejecting the new piece. In either case, the amount of bone that can be used is limited.
Why is 3D printing a better option?
Amanda Gorvin a middle aged Australian who has been suffering from excruciating back pain for over 30 years due to a deformed lower back vertebrae. Gorvin visited a surgeon 7 years ago begging for an answer, however was disappointed as the surgeon told her that surgery on her back was too risky to attempt. Spinal surgeons often fix a faulty vertebra by wedging a titanium implant into the damaged section, along with bone-graft tissue that slowly grows around the implant and fuses the joint. Gorvin’s vertebrae however was in such an irregular shape that no standard implant would fit in a correct manner. In an interview with Gorvin, she stated “I had always been such a positive person, so gung-ho, and I got to a point where I just felt defeated. The constant lethargy and exhaustion just debilitate your mind; more than anything you are just drained. By the time I got to see Marc, I was at my lowest point. I said to him, ‘Marc, I can’t do this anymore’. Then he said, ‘I’ve got this new thing’.” Marc Coughlan has been working with a melbourne company, repairing fractured skulls with plastic implants made from 3d printer. Anatomics, the melbournian company has recently designed a 3D printer that could build titanium implants. Coughlan believed that this was the right option for Gorvin, However she would have been the first patient to in the country to receive this operation, and coughlan would be the first surgeon to attempt it.
“Marc was honest about the risks,” she recalls. “He took me through the process; he suggested I could get a second or third opinion. But at that stage, I was ready for anything. Breakfast for me was two to three Nurofen. I said, ‘Sign me up’.
The operation was a huge success and Gorvin is now enjoying an unrestricted life. Although this was the first example of 3D printing, it is now one of many success stories, and with time there will be many more to come.
Professor Shah form Northwestern University in Evanston, Illinois, and her colleagues have developed an ink made mainly from hydroxyapatite. A mineral found naturally in bone, and PLGA, a polymer that binds the mineral particles together, and gives the implants their elasticity. The hydroxyapatite ink is very robust, and yet still ultra elastic. After the surgery has taken place , the implants are rapidly infiltrated by blood vessels and gradually turn into natural bone. Shah’s team calls the implant material “hyperelastic bone” also known as HB for short and claim it could heal a multitude of skeletal problems, from fractures and spine repairs to implants that can help rebuild faces after injury or chemotherapy. Adam Jakus, also at Northwestern, believes that the body’s repair processes mistake the hyperelastic bone for an incomplete bone that needs to be remodeled and brought back to its original shape. The body reacts this way because the implants so closely mimic the natural bone in their pore structure and mineral content.
While in an interview Dr. Shah mentioned
“Our vision is to have 3D printers in a hospital setting where we provide the hyperelastic bone ink, so surgeons can make individual implants within 24 hours”
“You could make off-the-shelf, or patient-specific implants using scans from patients,” she says..
Implementing 3D printing techniques in the field of bone surgery will be beneficial in many ways. No bone graft will be required which means no donors will be needed, and also no graft rejection is possible, even better there will be no autograft, which means the patient can keep all his/her bones. Bone graft surgery is usually quite expensive however if HB is used the cost can be cut tremendously, making such an operation lighter on many pockets as well appealing to others who simply couldn't afford it previously. Unlike bone grafts 3D printed HB is much faster to acquire and prepare than normal graft, furthermore the HB bone is modeled perfectly to the patient meaning there will be less time required for the surgeons to adjust the bone to tailor the patient.
3D Tissue Scaffold Printing On Custom Artificial Bone Applications
'Production of defect-matching scaffolds is the most critical step in custom artificial bone applications. Three dimensional printing (3DP) is one of the best techniques particularly for custom designs on artificial bone applications because of the high controllability and design independency.' (Nourmohammadi, Shahriarpanah, Asadzadehzanjani, Khaleghpanah & Heidari n.d.)
“Marc was honest about the risks,” she recalls. “He took me through the process; he suggested I could get a second or third opinion. But at that stage, I was ready for anything. Breakfast for me was two to three Nurofen. I said, ‘Sign me up’.
The operation was a huge success and Gorvin is now enjoying an unrestricted life. Although this was the first example of 3D printing, it is now one of many success stories, and with time there will be many more to come.
Professor Shah form Northwestern University in Evanston, Illinois, and her colleagues have developed an ink made mainly from hydroxyapatite. A mineral found naturally in bone, and PLGA, a polymer that binds the mineral particles together, and gives the implants their elasticity. The hydroxyapatite ink is very robust, and yet still ultra elastic. After the surgery has taken place , the implants are rapidly infiltrated by blood vessels and gradually turn into natural bone. Shah’s team calls the implant material “hyperelastic bone” also known as HB for short and claim it could heal a multitude of skeletal problems, from fractures and spine repairs to implants that can help rebuild faces after injury or chemotherapy. Adam Jakus, also at Northwestern, believes that the body’s repair processes mistake the hyperelastic bone for an incomplete bone that needs to be remodeled and brought back to its original shape. The body reacts this way because the implants so closely mimic the natural bone in their pore structure and mineral content.
While in an interview Dr. Shah mentioned
“Our vision is to have 3D printers in a hospital setting where we provide the hyperelastic bone ink, so surgeons can make individual implants within 24 hours”
“You could make off-the-shelf, or patient-specific implants using scans from patients,” she says..
Implementing 3D printing techniques in the field of bone surgery will be beneficial in many ways. No bone graft will be required which means no donors will be needed, and also no graft rejection is possible, even better there will be no autograft, which means the patient can keep all his/her bones. Bone graft surgery is usually quite expensive however if HB is used the cost can be cut tremendously, making such an operation lighter on many pockets as well appealing to others who simply couldn't afford it previously. Unlike bone grafts 3D printed HB is much faster to acquire and prepare than normal graft, furthermore the HB bone is modeled perfectly to the patient meaning there will be less time required for the surgeons to adjust the bone to tailor the patient.
3D Tissue Scaffold Printing On Custom Artificial Bone Applications
'Production of defect-matching scaffolds is the most critical step in custom artificial bone applications. Three dimensional printing (3DP) is one of the best techniques particularly for custom designs on artificial bone applications because of the high controllability and design independency.' (Nourmohammadi, Shahriarpanah, Asadzadehzanjani, Khaleghpanah & Heidari n.d.)
It gets even better
Although hydroxyapatite is a great solution and is far better than implants made from alloplastic materials (like PEEK or titanium) or even bone graft surgery, it still can be improved with the radical technology of 3D printing. “CT-Bone is a bone-like customized implant that can be 3D printed and is converted to real bone by the patient.” ('CT-Bone | 3D printing real bone | Xilloc' 2016). The patient will undergo a CT scan, biomedical engineers will then construct a patient-specific implant, and this will all done in collaboration with the surgeon. The designed CT-Bone is tailored specifically to the patient making it an exact fit. The design is 3D printed in calcium phosphate, the main constituent of natural bone. The 3D printing process has a very high accuracy, resulting in implants that fit perfectly onto the bone of the patient immediately without requiring any additional adjustments. After surgery and implantation, the CT-Bone unifies with the patient’s own bone in the following months. In comparison to Hydroxyapatite CT-Bone does not require a thermal process to increase its mechanical strength, subsequently displaying better bony fusion. Moreover the thermal procedure used for the other 3D printed ceramics causes shrinkage resulting in in an non optimal fit. Xilloc claim that their process of 3D printing allows complex shapes and 100% interconnected porosity, unlike other methods which have random porosity.
Osseointegration
"Osseointegration is defined as "the structural linkage made at the contact point where human bone and the surface of a synthetic, often titanium-based implant meet." ('The Osseointegration Group of Australia' n.d.) When a artificial bone is inserted into a person then it links with the muscles and bones. The body will then transfer the artificial bone into a real one, the muscles will grow and then the person will eventually have a normal body part. It restores the body part so the person can live a better life.