The bone printer
In 2017, Indian doctors conducted the first successful 3D-printed implant surgery, on a woman, in a Gurugram hospital. This January, they repeated their success with a Kenyan patient. Lounge explores how this cutting-edge technology can alter the landscape of medical science
On 6 February 2017, a specialized team of doctors at Medanta hospital’s Bone and Joint Institute in Gurugram inserted an unusual implant inside the body of a 32-year-old woman: the country’s first customized 3D-printed vertebra.
Two weeks before the operation, SG, a Hindi teacher, had walked into the office of V. Anand Naik, a senior surgeon at the hospital, complaining of tremendous pain in the neck and numbness in the extremities. “She walked in holding her head like so," explains Dr Naik in his office, cupping his hands and placing them beneath his chin. “The moment she removed her hands, her head would begin to slip forward."
Multiple MRIs revealed the 32-year-old was suffering from tuberculosis of the spine—a potentially fatal disease which eats into the backbone. “We found that the normal curvature of the neck was gone, and her spine was sliding forward along with the skull," says Dr Naik.
Physical trauma, cancerous tumours or accidents are the typical causes of spinal destruction on this scale. SG’s medical records reflected no such history, but for the past few months, she had been receiving high-dosage corticosteroid injections, prescribed by a different doctor, to treat infertility. The steroids caused her immune system to collapse, making her body susceptible to tuberculosis. When the disease hit, it spread far and wide, affecting various parts of her spine. “By the time she came in, there was no connection between her skull and the lower spine," says Dr Naik. “Everything was destroyed."
We are seated in his office at Medanta, a typical clinical room: X-ray box on the wall, a cluster of miniature spine models on the shelf, an examination bed. The doctor retrieves images of SG’s upper-neck MRI scans on his phone. The photographs show how, instead of a formidable column of cube-like vertebral bodies that form a healthy spine, almost each cervical bone (particularly the second and third) had been reduced to thin flakes. “The pus around the bones was causing a pincer effect on the spinal cord, so her limbs were beginning to become numb." More importantly, though, she was having difficulty breathing. SG was on the brink of going into respiratory paralysis. Quick action was essential.
Over the past seven months, as the pain escalated, the 32-year-old had visited several hospitals, consulted roughly 10 doctors, and always hit a roadblock. “I could not turn my neck or sleep," says SG, on the phone. “The pain became insufferable when I lay on my back. As soon as I lay down, the pain would be too much. I would cry and scream through the night." (SG declined to meet Lounge in person or get photographed, citing privacy concerns). Most doctors indicated that she would go on to live a life confined to bed, encased in an uncomfortable metal brace that would allow zero movement, while drugged with painkillers. Dr Naik, however, offered a different solution—one that would make her the first Indian to have a 3D-printed implant in her body.
Three centimetres in length, a prototype of the 3D-printed vertebra, designed specifically for SG, can disappear easily within my fist. I run my fingers over the coarse surface of this tubular structure. Dotted with holes of equal diameter, “the rough texture and micro-porous body allow the bone cells to go inside the implant, and eventually grow through and over it," explains Sanjay Kumar Pathak, who runs a 3D-printing firm called Global Healthcare in Delhi. “The process is similar to the organic way the roots of a tree grow." Pathak is a pioneer in providing 3D-printed surgical solutions in India. He co-designed the titanium vertebra, with inputs from Dr Naik.
Pathak’s office is in a corner of north Delhi’s sprawling industrial area, tucked away amid several small factories. A part of the office (which he runs under a separate company name with a business partner) focuses on designing and 3D-printing dental aligners—transparent plastic mouth guards that are more effective than traditional metal braces. The other part of the office (run under a separate company, of which he is the sole owner) focuses on designing medical solutions. He outsources the printing of the titanium implants to 3D printing companies in Sweden and France, since owning a medically certified titanium printer in India costs close to Rs1 crore. Then, there’s also the cost of running and maintaining the machine, and employing skilled operators.
It was in 2015 that Pathak heard about a conference, “Inside 3D Printing", in Mumbai. Pathak knew doctors were always looking for new high-end technology that could assist in surgery. “When I attended the conference, I started thinking about 3D printing as a medical solution that could be provided in India. I knew it was going to be difficult, but achievable."
In 2016, he approached the All India Institute of Medical Sciences (Aiims), in Delhi, offering 3D-printed surgical models (not implants)—identical organ replicas—which would help surgeons perform critical, invasive surgeries better (see box for a detailed overview). As word got around, Pathak’s name came to be associated with healthcare 3D printing. In 2017, Medanta approached him to take things a step further and design a 3D-printed implant.
Pathak says he gave the titanium vertebra practically for free: SG was his first customer. Today, however, 3D-manufactured implants can cost anywhere from Rs1.5-7 lakh (inclusive of the cost of labour and material) in the Indian market. Abroad, these implants can cost anywhere from Rs25-50 lakh.
Since the surgery, Pathak has been working closely with other Indian hospitals. Eight months ago, for instance, Max Super Speciality Hospital in Saket, New Delhi, approached Pathak to reconstruct the skull of a gun-shot victim. The medical team scanned the patient’s facial structure and learnt that his right eye socket and part of the forehead directly above it had been shattered beyond repair. Pathak successfully got a titanium replica of the fractured parts of the skull printed, but the patient did not return for the surgery.
“The piece is lying safely with me," Pathak says, taking out the implant and placing it on the table. “The patient had financial problems, but he will return when he has to." He then retrieves a peculiar, bright-yellow plastic skull from his drawer. “This is a 3D-printed copy of his face," Pathak says, pointing to the deformed piece. “This is what his face looked like when the patient was admitted." Looking at the shattered skull can be disorienting: A large chunk above the right eye socket is missing, the gouged-out bit defined by sharp, jagged edges. As a solution, Pathak designed an asymmetrical titanium structure which would be placed over the broken part completely, making the skull whole again. The implant carries holes similar to SG’s printed vertebra.
Recently, a handful of companies have begun providing such implants to hospitals in India. In January, when the team at Medanta began work on a particularly tricky case, they turned to one of Pathak’s competitors, XL Orthomed.
It was for 11-year-old Lakita Mwangi, an active gymnast and swimmer at her school in Kenya, who for over a year had been complaining of a subtle pain in her right knee, almost always after sports class. When the pain escalated, and began recurring daily, her mother Joyce Mwangi suspected cancer. “Seven years ago, Lakita’s father had died of colon cancer," says Joyce Mwangi. “I realized my daughter might have cancer too."
Mwangi is a single parent who runs a small business in Kenya. Shy and soft-spoken, she is almost inaudible when she speaks. “When I took Lakita for a medical scan in Kenya, the doctor confirmed that she had a tumour. In my country, though, the only solution is to amputate the leg. But I said, ‘That won’t do.’" On the advice of friends who live in India, Mwangi bought her daughter to Delhi in September.
Mwangi first approached another hospital, where the doctors did a biopsy test. “They took too much time to do the tests." So, she turned to Medanta in December. “Lakita’s mother was adamant that she did not want to amputate the leg," says Sanjiv K.S. Marya, who heads the Bone and Joint Institute. “I remember her asking, ‘What else?’"
Most adults suffering from bone sarcoma (cancer of the bone) have the tumour sliced away, and then have the remaining leg bone fused to the joint through arthrodesis. The problem with this process is that while patients can walk after surgery, they have difficulty bending the knee. But Lakita had her whole life ahead of her. Dr Marya and his team began looking into the solutions that 3D-printing could provide.
The first 3D printer was designed in the 1980s. Its inventor, Charles Hull, built a machine that used acrylic ink and functioned by printing layers. Layers would be added in turn, and the ink, when exposed to UV laser light, would harden to form the required object. In 1983, Hull successfully printed a black eyewash cup. The solid imaging process (known as stereo-lithography) is commonly known today as three-dimensional printing. Hull went on to patent the machine three years later, and subsequently co-founded 3D Systems in California, to commercialize the invention.
Thirty-five years later, 3D printing can potentially influence almost every realm of life. The machines now print in various metals, including gold and silver, as well as ceramics and wax. In fact, we can now even print edible food. For instance, “Foodini", designed by Natural Machines, can produce anything from ravioli to pizzas; while US space agency Nasa has invested in a 3D-printer prototype that can print food in space. The possibilities are boundless, portending, for the optimistic, the utopian future of Star Trek, where 3D food printers have ended the need for war and competition amongst humans. Another famous piece of science fiction, Michael Crichton’s Westworld, imagines a future where human-like figures are 3D-printed in a sterile, glass-walled underground laboratory.
While “printing" androids is still far in the future, scientists are currently attempting to print biocompatible tissues, muscles and organs. Attempts at growing human tissue are a common avenue of scientific exploration, but they have been repeatedly unsuccessful, since artificially created tissues have not been able to thrive for long as living organisms. But now, researchers at North Carolina’s Wake Forest University have constructed a bio-printer that can engineer fully-functional organs and tissues (with blood vessels) that can, hypothetically, be inserted into the human body.
The bio-printer at the Wake Forest Institute for Regenerative Medicine uses hydrogel (a water-based “ink" carrying a patient’s cells), which is used to promote cell growth. To print an ear cartilage, for instance, the bio-printer, equipped with small nozzles, deposits hydrogel as well as “bio-degradable, plastic-like material in order to form the tissue ‘shape’", says Anthony Atala, director at the Wake Forest Institute for Regenerative Medicine, on email. In addition, the shape is layered with a printed network of micro-channels throughout, which allow “nutrients and oxygen from the body to diffuse into the structures and thus keep them alive while the tissues develop their own system of blood vessels".
The scientists at the institute have managed to successfully implant this cartilage in laboratory mice, where the cells have exhibited no signs of failure. Though the bioengineers have not implanted these artificially manufactured parts into humans yet, this technology is a breakthrough. In India, according to a 2017 report published on the NDTV website, about 500,000 people die every year due to the unavailability of organs. While 200,000 need liver transplants, 150,000 suffer from kidney diseases and the rest from cardiovascular diseases. If printed organs are available for liver or heart transplants, patients in line for organ donation would no longer have to wait years for a “right match". In addition, the question of organ rejection, a common occurrence during transplants, would not arise. A brand-new organ could be printed from the patient’s own cells within days.
In similar vein, researchers at the Feinberg School of Medicine at Northwestern University were recently able to print bio-prosthetic ovaries for mice, enabling them to successfully give birth. The real breakthrough, however, will be when bioengineers are able to implant these in cancer patients who have been sterilized due to treatment, to help restore fertility.
Our ability to print large organs such as a kidney or a heart, however, will “probably not exist for many decades to come", says Jason Chuen, director of the Austin Health 3D Medical Printing Laboratory, on Skype. Chuen says certified regulatory bodies would have to work on a blueprint on the ethics behind implanting such organs, if and when the technology allows us to create them. “At the moment, we don’t have a way to define what the responsibility of each person who will be a part of this process would be," says Chuen. “So, if I was to print an organ, how would I know whether it is produced to a certain standard? How do we create some sort of manufacturing quality control? These are questions which have not been answered yet. There is a lot of discussion at WHO (World Health Organization) and the FDA (food and drug administration) about how such a system would work."
Dr Marya has a packed schedule. Every now and then, he pulls back the sleeve of his coat to check the time. He is scheduled for a surgery right after our conversation. When I ask about the complicated procedure that Lakita, the young girl from Kenya, needed, he relaxes his shoulders and leans forward.
“With young patients who still have a few years left to grow, arthrodesis is not the best solution," explains Dr Marya. As the child grows, the length of the legs becomes incongruous—one continues to grow while the operated leg remains the same size. A team of doctors headed by Nishant Soni, a hand and limb reconstructive surgery specialist, and Chandeep Singh, the associate director at the Bone and Joint Institute, concurred that Lakita needed an expandable implant that could be routinely manipulated in length to match her normal growth. “This means that it has a provision where, every six months, we can make a small stab—an incision into the implant—and increase it by 5mm," explains Dr Singh.
Mwangi was sceptical. “At first, I was scared about having a 3D-printed implant," she recalls. “I was wondering whether it would work." The implants are expensive, and an overarching concern is whether this new technology can be as effective as traditional autograft procedures, where a piece of bone is severed from the patient’s body (normally the rib cage or the hip) and transplanted to another part of the body. In SG’s case, for example, autografting as an alternative was impossible due to the serious, deteriorating condition of her spine. The implant was her only hope. For patients like Lakita, who have bone tumours, printed implants are a viable option.
“So I did some research on the internet," continues Mwangi. “And learnt that in the US they’ve performed such surgeries on children. That’s when I told the doctors to go ahead."
Lakita’s personalized 3D-printed titanium implant is designed to function as a knee joint; what makes it even more remarkable is that it was also uncemented. “We don’t use cement to glue the implant to the bone," explains Dr Marya. “If you fix it with cement, the chances are that the implant will loosen or de-bond as the child grows." In order for the implant to integrate completely with the bone, it needs to be coated with a special substance called hydroxyapatite. Hydroxyapatite is not available in India yet, so the piece had to be sent to France for the coating.
After the surgery, Lakita, who now has a semi-open cast around her leg, makes 1-hour visits to the hospital, six days a week, for physiotherapy exercises. “The first thing Lakita asked when we met was, ‘Will I be able to swim?’" says Dr Soni. “While she might not be able to perform gymnastics, she will be able to swim in the future thanks to the implant."
With the advent of 3D-printed bone implants, one would imagine there would be more and more patients opting for 3D bone implants. But in India the cost is proving prohibitive. Dr Marya, however, believes this will soon change. “Once we begin using it more frequently in healthcare, the cost will come down," he says. “When I returned to India, from London 25 years ago and began practising here, there was hardly anybody doing knee-replacement surgeries. I found it difficult to convince people about what it was. Then came a strange phenomenon, where a lot of people suddenly began performing knee-replacement surgeries—but with inadequate training. Some patients insisted that they wanted knee-replacement when they didn’t need it, and because of that, their results were suboptimal. Then they would wonder what went wrong.
“I think for any surgery—especially ones with expensive implants—the first thing a surgeon must be mindful of is patient selection. If you don’t select properly, the procedure will not go correctly." Perhaps this is why, after SG’s procedure, it took Medanta almost a year to schedule its second 3D-printed implant surgery.
Today, SG has recovered completely. She can walk and engage socially with friends—a life remarkably different from the one several doctors envisaged. Three months after her surgery, Lakita too can stand on her feet with the assistance of a walker.
3D-printing is beginning to revolutionize the medical industry, and though it still may be at an embryonic stage in India, it is clear that the country will play a crucial role in embracing this new technology in the future—changing millions of lives forever
3D printing: the big impact
Why 3D-printed implants win over ready-made ones
Three-dimensional printed implants are tailor-made, designed accurately to meet a patient’s anatomical requirements. They have a strong advantage over ready-made implants. “Sometimes, in order to fit a ready-made implant, the surgeons are forced to shave off surrounding bone in order for the implant to fit," says Sanjay Pathak, who runs Global Healthcare, which offers medical solutions to hospitals. “With 3D, this is no longer required."
In addition, the implant has a coarse texture, which allows the bones to grow over and integrate easily with it. “The rough surface is achieved through this kind of printing," explains Pathak. “Implants which are traditionally made have to be scratched manually in order to get the required unevenness. This takes more time for the piece to be ready for a patient; and manual scraping would produce some kind of a harsh surface, but not as good as 3D printing."
The implant inserted in SG was designed using advanced software. V. Anand Naik’s team of doctors took a CT scan of her damaged vertebra, and, with Pathak’s help, used it to virtually recreate and construct an intricate, three-dimensional image. On this digital model of her spine, they removed the diseased parts that floated between the first and fourth vertebral bones, and measured the gaping void. Pathak then designed a titanium implant that would sit snugly between the first and fourth bones. Titanium is a metal commonly used in orthopaedic surgeries; it’s preferred for its durable quality and biocompatible characteristics.
While printed implants are still a rarity in India, hospitals have been using 3D printers to make uncannily realistic (and identical) anatomical models for examination and practice before going into a surgery. This has been happening for a few years now. Rather than relying on two-dimensional CT scans for surgery, surgeons can now inspect, dissect and probe the printed replicas to assess what they may encounter with the real organ in the operating room. Not only does this ensure that surgeons are better prepared before a crucial surgery, it means that nothing is left to chance. It saves a lot of time and helps them tackle otherwise unforeseen complications.
This is particularly valuable for small-sized organ or bone-related surgeries. In 2014, for instance, a team of doctors at the Jawaharlal Institute of Postgraduate Medical Education and Research (Jipmer) in Puducherry needed to fix the deformities in a three-year-old’s skull. For this, they used a 3D-printed replica of the child’s skull. “With the replica...we know where the holes in the skull are, and it will help us cut the bones with precision to get optimal results," Dinesh Kumar S., associate professor at Jipmer, who headed the surgical team, had said in an interview to Mint in August 2014.
Today, multiple hospitals, including Aiims, Max Super Speciality Hospital, Apollo and Fortis Healthcare, take the help of 3D-printed organ replicas.
FIRST PUBLISHED21.04.2018 | 08:56 AM IST
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