How a bit from here could ease pain there
NOSE CARTILAGE TO REPAIR KNEES
PIONEERING research using cartilage from a patient’s nose to repair damaged knees is showing promising results. Nicola Mueller, 39, a mechanic from Basel, Switzerland, was one of the first people in the world to undergo the procedure, as he tells RACHEL ELLIS.
THE PATIENT
FOUR years ago, my knee became painful and weak. When I went to see a doctor, he said the cartilage had worn away through years of exercise — the same damage as people get through wear and tear in old age.
I had to stop sport altogether, which was a real blow because it’s been a huge part of my life.
Doctors said there was very little they could do because, as cartilage doesn’t have its own blood supply, it cannot repair itself.
For the next year, I managed as best I could, but it didn’t get any better and I still had the pain.
Then, out of the blue, my doctor asked if I would be interested in taking part in the first human trial using cartilage from the nose to mend my damaged knee.
The theory was that nasal cells grown in the laboratory to create a graft are better at mending cartilage damage in the knee than those actually found in the knee joint.
I was delighted to have the chance to try something new.
The first part of the treatment was done under local anaesthetic and involved taking a 6mm sample of cartilage cells from my septum — the wall that divides the nostrils. It wasn’t painful, but felt a little strange. It took around 20 minutes — doctors took a sample using a tiny instrument a bit like a hole punch.
I was allowed home straight away, and my nose was sore for about a week.
The cells from my nose were taken to a laboratory and allowed to ‘grow’ for four weeks.
The surgery was then carried out under general anaesthetic.
In the 45-minute procedure, the graft was cut to the required size (a 4cm square) and stitched into place through a 1cm incision on the right side of my knee.
I was in hospital for four days afterwards and on painkillers for the first two weeks, with my leg in a fixed brace for five weeks, as I was not allowed to put any weight on it.
I was then gradually allowed to move it and underwent physiotherapy twice a week for ten weeks. Eight weeks after surgery, I could put full weight on the leg. Because I am a mechanic and on my feet all day, I had two months off work while I recovered.
By the time I went back to work, my knee felt much better, although there was still a little bit of pain.
After six months, I was allowed to start playing sport again, which was fantastic, and, after a year, my knee felt completely back to normal. It’s now perfect.
THE SPECIALIST
Ivan MartIn is a professor of tissue engineering at the University of Basel and University Hospital Basel in Switzerland.
PATIEnTs with cartilage problems are usually offered a number of surgical treatments, such as an arthroscopic debridement (cleaning out the knee and trimming damaged cartilage) or microfracture (drilling tiny holes in the bone of the knee to encourage cartilage to regrow).
But there are major drawbacks with these — they often take a long time to heal or do not heal well, and the problem can recur.
The idea of mending knee injuries with nose cartilage came about 15 years ago when we discovered, by chance during laboratory studies, that cartilage cells from the septum in the nose are better at repairing knee damage than cartilage from the knee or ankle.
This might be because cells from the skull generally have superior properties and may be able to regenerate better.
But the big question mark was whether these cells would work in the knee. In 2008, we carried out laboratory experiments exposing nose cartilage cells to typical strains put on the knee and found that they could withstand them better than cartilage cells found in the knee.
We also looked at the cells of nose and knee cartilage under the microscope and found that they are largely the same.
After a study on goats, published in the journal science Translational Medicine in 2014, confirmed the benefits, we were allowed to treat the first patient.
We have now treated 18 patients, including nicola, all of whom were under 55 and had fresh cartilage injuries — if cartilage injuries are not treated promptly, they start to affect the joint, making the issue more complex. The septum was chosen because taking a biopsy from there will not affect the structure of the nose, it’s relatively easy to access and it doesn’t involve major surgery.
CElls from the nose biopsy were put into a petri dish and exposed to growth factors for two weeks to encourage them to grow. They were then transferred and grown for another two weeks in collagen, a scaffold that encourages cells to deposit new proteins, generating new tissue.
After four weeks, there was enough new tissue to create a graft — which looks like a white and glossy patch.
During the procedure, the surgeon removed the damaged cartilage, then the graft was cut to the required size and shape for the patient, and fixed in place adjacent to the remaining healthy cartilage using absorbable stitches and biological glue.
After the operation, patients were asked to take rehabilitation slowly to give the new cartilage the best chance of working.
Results from ten patients (eight men and two women), published in The lancet in October, found the procedure was safe, and nine patients had less pain, improved knee function and better quality of life up to two years after the operation compared with before surgery. (The tenth patient was excluded as he had suffered another sports injury.) Patients’ ages did not affect the outcome and the benefits seemed to increase with time, unlike traditional techniques such as microfracture, where the benefits start to reduce within months.
What was extremely positive and surprising was that, using MRI technology, we could see that the nose cartilage graft in the knee had integrated with the surrounding cartilage — we hope this means the positive effects experienced by the patients will last.
We have now received EU funding to extend our research to treat 108 patients aged 18 to 65 with ‘fresh’ injuries who will be treated in four centres in Italy, Germany, Croatia and switzerland. We will treat the first patient this month.
If everything goes well, we could offer this treatment for sports and traumatic injuries in about five years.
We also hope that, one day, it could be used for the treatment of chronic joint problems, such as osteoarthritis.