Professor Adrian Wilson, MBBS, BSc (Hons), FRCS, FRCS Tr & Orth Specialist Knee Surgeon (Professor), tells us what we need to know about exciting new regenerative treatments that take centre stage for knees in the world of orthobiologics
Around one-in-five people over the age of 45 has osteoarthritis in the knee. It is a painful thinning of the cartilage that can impact mobility and lifestyle. The knee is also a hot spot for trauma – a ruptured ligament or torn cartilage, tendonitis or a dislocated kneecap.
For severe and chronic persistent pain in the knee, a full or partial knee replacement is often an option. However, although it is safe and reliable, it has side effects. Sadly recent studies have shown that knee replacements in the young have a high failure rate. In 2019, a review of 65,000 patients with a 10 year follow up showed a very high failure rate in young people with 35% of patients under 55 failing within seven years with a mean of four years. Then the second knee replacement wasn’t shown to do well. This is a disaster and shows the importance of looking into all the joint preservation options before embarking on any form of knee replacement surgery.
I specialise in joint preservation, sports injuries and knee problems in both adults and children, using techniques that I have developed over a number of years. As a Consultant Surgeon, my first thought is always about restoring anatomy and function and preserving the native knee joint. I always look for non-surgical options first and try and found the least invasive intervention possible before embarking on more invasive surgery.
This is a view shared by many surgeons and the use of Ortho Biologics has exploded in the last 10 years as new treatments have come online for managing muscle tears, ligament injuries and wear and tear arthritis.
It is in this field that several new exciting regenerative treatments specifically for knees are emerging which deserve consideration before surgery, or as an alternative to surgery altogether.
It is key to tailor the regenerative treatments to the patient and offer a bespoke option for their particular problem rather than adopting a one size fits all approach. Patients don’t want invasive surgery unless it is really necessary and are now actively seeking out newer less invasive treatments.
Arthroplasty or joint replacement
Here we have the option of completely replacing the knee with a total knee replacement or going down the less invasive route of offering a partial knee replacement. There are three compartments in the knee and each can be selectively replaced with a partial resurfacing or replacement.
A partial knee replacement involves a smaller incision and is significantly less invasive than the traditional total knee replacement surgery and offers quicker recovery, (although this would still be months) and less pain after surgery and less blood loss. Because the bone, cartilage, and ligaments in the healthy parts of the knee are kept, most people say that a partial knee replacement feels more ‘natural’ than a total knee replacement, and it usually bends much better.
This stands for platelet-rich plasma and is a very effective way of managing early arthritis and muscle/tendon injuries. We have known about the healing effects of PRP for more than two decades and we have 14 level 1 randomised controlled studies which show how well PRP performs compared to conventional treatments like cortisone injections. It is a highly effective treatment, easy to carry out in the outpatient setting. It involves taking a small amount of blood, about the same as you would have if you were having a blood test. This is put into a centrifuge for 10 minutes and the cells fall to the bottom and the plasma stays on the top sand can be siphoned off and used to inject a painful joint/tendon. It is useful in treating moderately advanced arthritis but not in end-stage bone on bone wear and tear.
Adipose Tissue Therapy or microfragmented fat
Adipose Tissue Therapy uses mesenchymal stem cells (MSCs) taken from a patient’s own fat by taking a small amount of fat using liposuction. It is minimally invasive and highly effective. The procedure takes 45 minutes and is minimally invasive with virtually no downtime.
Most patients are able to carry on with their lives as normal after the procedure in terms of work and recreational activities. The most commonly used system is lipogems which has been in use for a decade and has the best data and results. Over 40,000 patients globally have been treated with lipogems for osteoarthritis.
The way it works is that the fat is taken and then washed, fragmented and filtered and then injected under ultrasound guidance into a painful joint. The small clusters of fat contain huge numbers of pericytes which are pre stem cells and become activated. They, in turn, then start to release proteins which switch off inflammation and promote healing and the effect can last for several years.
The results in multiple centres have shown it to be very safe with virtually no complications and a success rate comparable to total knee replacement in terms of pain relief and improvement in function.
It is also possible to harness MSCs from bone marrow (BMAC). In younger people, this can be highly effective but in older people the activity of the bone marrow significantly deteriorates and the stem cells are present in far smaller numbers, so for this reason, micro- fragmented fat is the preferred source of MSCs.
Knee realignment surgery (osteotomy) involves taking pressure off the damaged side of your knee by dividing the bone and realigning the limb, so the leg is straight. This realignment allows your body weight to be distributed evenly through the knee joint away from the damaged area to the undamaged area. This is highly effective and has similar results to partial knee replacement with 85% of patients reporting a good or excellent outcome in our series and those published by other groups. It doesn’t burn any bridges and the long-term results show excellent results at 10 years plus. Anyone under the age of 65 and active should consider this option. And for people who are still active and older, the results are also extremely good.
One of the big breakthroughs in the last five years is making the recovery quicker and we have achieved this by pioneering new techniques for planning and carrying out the procedure and making it less invasive. I am very lucky to have been heavily involved in the developments of several new techniques that make the surgery less painful, more accurate and allow a quick recovery.
Joint distraction uses the body’s natural healing processes to repair damaged cartilage in the knee. We learnt about this concept from the foot and ankle surgeons who have been using distraction for the ankle for more than 20 years. The procedure takes 30 minutes and is minimally invasive. By applying a frame across the knee, we can rest the joint and allow an up-regulation of the patients stem cells that promote healing and are anti-inflammatory. Large studies in the Netherlands have shown that knee joint distraction outperforms knee replacement surgery at five years. But with the joint distraction, no bridges have been burned and the patient can still undergo a knee replacement in the future. This will become a very common way of managing wear and tear arthritis in younger people.