In a pilot study of 10 patients with damaged knee joints, physicians harvested cells from their noses to engineer new cartilage tissue and transplant it into their damaged knees. In a paper published in The Lancet, the Switzerland research team explains how 2 years after transplant, most of the patients had developed new tissue similar to normal cartilage and reported improvements in knee function, pain, and quality of life.
However, the authors points out that while the results of their phase I research are promising and show the approach is possible and safe, there is even now a long way to go before such a procedure can be approved for routine use with patients.
They note that the observational study only involved a smaller group of patients, there was no control group, and the follow-up was quite short.
There now needs to be randomized trials – with longer follow-up – that compare the promising therapy with conventional alternatives
Lead author Ivan Martin, adds:
“Furthermore, in order to extend the potential use of this technique to older individuals or those with degenerative cartilage pathologies like osteoarthritis, much more fundamental and pre-clinical study work need to be done.”
Study unique for using nose cells to fix knee damage
About 2 million individuals in Europe and the United States are diagnosed with damage to knee joint cartilage every year, caused by injury or accident.
There are medical procedures – such as microfracture surgery – that can prevent or delay the onset of cartilage degeneration following injury or accident, but they do not regenerate healthy cartilage to protect the joints.
There have also been attempts to use cartilage cells or chondrocytes from the patients’ own joints to develop new cartilage in the joint, but these have not been very effective at generating the right structure and function of the cushioning tissue.
One of the unique features of the new study is that Prof. Martin and colleagues used chondrocytes harvested from a site far away from the broken joint – from the patients’ nasal septum. These cells have a unique ability to develop new cartilage tissue.
New tissue of similar composition to cartilage
For the study, the team enrolled 10 patients (age 18-55) with full-thickness cartilage damage to the knee and performed a biopsy from their nasal septum under local anesthetic. They grew chondrocytes harvested from the biopsy tissue by stimulating them with growth factor for 2 weeks.
The team then took the cultured new cells and seeded them onto “scaffolding” made of collagen and grew them for another 2 weeks. The result was a 2-millimeter thick graft of new cartilage measuring about 30-40 millimeters.
Each patient then underwent surgery where the damaged knee cartilage was removed and replaced with their own cultured graft cut into the appropriate shape.
After 2 years, scans showed new tissue of similar composition as cartilage had grown at the affected sites.
9 of the 10 patients – one was excluded because of sports injuries not associated to the trial – also reported significant improvements in the use and function of their knee and reduction in pain, as compared to pre-surgery.
The authors state there were no reports of adverse reactions to the surgery, although there were two reports of injuries not relatred to the procedure.
Sufferer age does not seem to affect success
In an accompanying comment article, Dr. Nicole Rotter and Dr. Rolf Brenner – say the trial shows an significant advance towards less invasive, cell-based repair technologies for articular cartilage defects.”
The main reason they give is that the cells were not taken from healthy tissue near the site of injury but from a completely unaffected part of the body, which avoids the risk of harvesting affecting the damaged joint.
They also mention the promising result tha patient age does not seem to affect the success of the procedure.
However, like the study authors, they found that only longer-term randomized, controlled studies – that among other factors test the quality of the repair tissue – will be required before we can say whether this procedure is likely to gain regulatory approval and reach clinical use.
“Our findings confirm the safety and feasibility of cartilage grafts engineered from nasal cells to repair damaged knee cartilage. But use of this procedure in everyday clinical practice is still a long way off as it needs rigorous assessment of efficacy in larger groups of patients and the development of manufacturing strategies to ensure cost effectiveness.”