Computer ‘printed’ implant can heal broken bones

A groundbreaking implant to treat complex bone fractures can help challenge cases that have previously led to amputation.

Russell Neighbor, 60, a construction consultant from Ash, Surrey, tells ADRIAN MONTI how it helped him walk again.

The patient

Two years ago, I hung Christmas lights outside our house when I stretched, overbalanced, and fell off the ladder.

I hit the ground 20 ft lower with such force that it shattered the bones in my right lower leg. My shin was sticking out of the back of my lower leg. Then I fell backwards, which meant that the protruding bone buried itself in the grass.

It was traumatic, but the adrenaline didn’t hurt me. My wife Rachel was amazingly calm and stayed with me while a neighbor called an ambulance.

In the hospital, X-rays showed that I had fractured my shin, tibia, and fibula, the fibula of my right leg.

By then the pain had started to increase, so I was given morphine and ketamine before being transferred to St George’s Hospital in Tooting, South West London for emergency surgery.

Two days later, I had surgery to implant screws and rods to hold the broken bones in place with a metal scaffold.

I have spent almost a month in the hospital. I also needed skin grafts to repair where the bone had pierced the skin, using skin from my right thigh.

I went home in January with my lower leg still in a metal frame.

Before the accident, I enjoyed long walks with our dogs, as well as cycling and fishing. Now I couldn’t do all that anymore, because I had to use a wheelchair and crutches.

Then, in November 2019, almost a year after the accident, X-rays showed that the bones are not knitting together. My consultant said that if my leg is left untreated, my leg would never be stable enough to walk back on. He said my options included amputating my lower right leg.

Then he said there was a new process in which the badly damaged bones were removed and replaced with a metal cage, made of a titanium alloy, made using 3D printing technology.

Healthy bone was removed from my hip and placed in the cage. It would require two surgeries, but without this I could lose my leg.

In late January of this year, 6 cm of the crushed tibia and fibula was removed under general anesthesia and a temporary implant – called a spacer – was inserted between the ankle and the remaining tibia.

Once the spacer was in, I couldn’t put any weight on my leg, but finally the second surgery went through mid-April. It took about five hours – and the physiotherapist made me walk on crutches the next morning. After four nights, I went home with crutches and a wheelchair. I’ve had the wheelchair for two months and finally stopped using the crutches in September.

When Rachel takes our dogs, I will follow them, but I can walk for an hour or more.

I started in the gym and hope to cycle again. I recently used a stepladder to paint the greenhouse, but I don’t think Rachel will ever want me to turn the Christmas lights back on.

The surgeon

Alex Trompeter is a surgeon for orthopedic trauma and limb reconstruction at St George’s University Hospital in London.

When a patient has a complex fracture like Russell, we normally try to fix the bone in place and perform skin grafts.

However, 20 to 30 percent of those with this type of injury suffer from an infection, a non-union (in which the bones are not stuck together), or both.

One possibility is not to heal the bone, but that is only for not very mobile, elderly patients. About 5 percent of these cases lead to amputation.

Another option is a bone graft, which preferably uses the patient’s bone, called an autograft, to fill the gap between the bones.

The last option is bone transport; where the bone is broken above the level of the damaged bone and pulled down slowly, ‘obliterating’ the defect. New bone shapes to repair the intentional fracture. But this means that you have to have a steel cage around the leg for months.

We now have another option where we cut out the ‘bad’ bone at the bottom of the shin and fill that gap with a custom cage-like implant that is then filled with bone harvested from the thigh.

The main advantage is that recovery is much faster, patients can walk within two weeks. After a normal bone graft, it can take them six weeks to put on weight and require a cage for months.

A 2018 study for the American Orthopedic Foot and Ankle Society with 15 patients had an 87 percent success rate.

Once Russell decided to proceed, we performed 3D CT scans of his lower leg and ankle. These were shared with the implant maker in Texas, who made a cage using 3D printing technology.

While the implant is being made, the patient has the first of two surgeries to remove the non-healing bone.

The leftover shin is then cleaned and we put a bone cement ‘spacer’ (which also contains antibiotics to kill any infections) and I put a metal scaffold around the lower leg, held in place by screws. The second operation takes place six to eight weeks later. A metal bar of 12 inches is inserted through the heel, which rises into the center of the existing part of the shin and holds the cage in place.

The bar melts the ankle so that it is motionless but pain-free. During the five-hour surgery, I look at X-rays to make sure the implant is properly aligned.

We then start to fill the cage with bone cells harvested from the femur with a device that is somewhat like an apple corer that goes into the bone marrow.

This incision leaves a 2 cm scar on the patient’s thigh. The femoral marrow will regrow in a few weeks.

We have to wait five days to test biopsies for infection. If all is well, the patient can go home.

There will be follow-up appointments to check if the wounds are healing. For the next six months, patients undergo intensive physical therapy, and I see them for follow-up. It is hoped that the recovery will level off after 18 months.

The implant costs about £ 20,000.