Regenerating Knee Cartilage with intra – articular injections of peripheral blood stems with PRP improves clinical outcomes in knee surgery, a new 5 year study proves positive results.
In this study, 20 otherwise healthy Caucasian patients were chosen who had a knee lesion which was otherwise non responsive to non surgical interventions. The patients consisted of 7 women and 13 men, aged from 21 to 47 years old. The criteria was clear – the lesion showed no improvement with non surgical treatment for up to 4 months, there was no osteoarthritis present, no systemic disease, after MRI the lesion was 8.5 -25 mm in diameter, the time between diagnosis and treatment was less than 6 months, the patient was fit for surgery, and each patient would undergo the exact same treatment by the same surgical team including anaesthetic and management of pain.
The patients were chosen as all performed physical activity 5 times a week and MRI scans were taken 6 months before the operation to assess the knee condition.
Professor Adrian Wilson of the Regenerative Clinic, where PRP is used, commented, “This is a great paper to promote the use of orthobiologics in knee surgery. In this paper a commonly performed operation to regenerative cartilage was carried out (microfracture). In the group which also received PRP there were significantly better results of cartilage regeneration at 4 years follow up. I’m convinced it will become standard practice to use PRP for improved outcomes for cartilage regeneration surgery and is already the standard of care for the OS and The Regenerative Clinic.”
Patients with knee Chondral lesions- all patients had this common type of knee injury which shows damage to the articular cartilage, the smooth substance that covers the ends of the bones and keeps them from rubbing together as you move.
Cartilage, or chondral, damage is known as a lesion and can range from a soft spot on the cartilage or a small tear in the top layer to an extensive tear that extends all the way to the bone. Sometimes a piece of cartilage can actually break off and cause damage to the cartilage and bone as it grinds into the joint.
The lesions can be degenerative due to wear and tear, osteoarthritis, or due to trauma such as falling on the knee, jumping and landing, or playing a sport which requires a rapid change of direction.
There are not always clear symptoms at first as there are no nerves in the cartilage but over time these lesions can disrupt normal joint function leading to pain,inflammation, and limited mobility. The lesion can then gradually worsen and cause additional problems to the joint.
The cartilage lacks blood supply, so the body cannot usually repair chondral lesions on its own. Some severe tears that injure bone can promote growth of fibrocartilage , scar tissue which is a tough material that replaces missing articular cartilage but it is not as smooth as a gliding surface for the joint to articulate.
To treat this injury is difficult and has proved to be an important study because of this low self healing capacity of the articular cartilage and standard health care treatments which do not consistently restore both structure and function. The cartilage in the knee only tends to regenerate with fibrocartilage and the knee itself responds poorly to mechanical stress over time.
This study aimed to use typical arthroscopy procedure with PRP stem cell therapy.
Arthroscopy- each patient underwent arthroscopy surgery, which is a minimally invasive procedure that allows the doctor to examine the tissue inside the knee. A thin fibre optic light and magnifying lens and tiny television camera are inserted into the knee. A few additional instruments are inserted through small incisions around the joint.
For 3 consecutive days before the surgery patients received a dose of 30 MU of filgrastim each day.
On the day of the surgery 450 ml of blood was obtained and centrifuged to remove coat and plasma. It was then centrifuged again to obtain PRP fraction and preserved for later use.
After surgery the lesion was measured and healthy cartilage reached and the calcified plaque resected. Following the procedure 10ml of PRP was injected into the lesion. The joint was immobilised for 24 hours and injections of cryopreserved PBSC and PRP were administered into the joint once a week for three weeks. Each patient underwent the same pain management and rehabilitation protocol. The patient had to avoid loading the limb with no weight bearing for 4 weeks. Exercises were performed with only stability and flexibility in mind and patients were to avoid running and jumping up to one year after.
Clinical evaluation- the IKDC or International knee documentation committee insured that visual analog scale scores were recorded before surgery, 6 months, and then 1 year after surgery, then yearly for 5 years to collect the data. They were evaluated by musculoskeletal radiologists who were blinded to the patients statistics and data so they were completely unbiased. Comparisons were made with regards to the cartilage state of repair and using a specific score system. Each year improvements were recorded and there were no infections, tumours,or synovitis reported at the end of the follow up and trial. The injections with platelet rich plasma improved these clinical outcomes for knee chondral lesions at the end of the 5 year follow up.
What is PRP- Platelet Rich Plasma? This therapy is also known as Autologous Conditioned plasma. PRP takes advantage of the bloods natural healing properties to repair damaged cartilage in the knee and reduces pain, inflammation, and improve joint function.
The treatment of PRP in the knee facilitates tissue healing, shows the capacity in the results for restorative healing, inflammation modulation and actual cartilage repair.
PRP supports the body’s self healing processes through its own cells. Blood which is mostly made of plasma also contains solid components such as red cells, white cells and platelets. These platelets are important for clotting blood and contain proteins called growth factors which are important in the healing of injuries. With a higher concentration of these growth factors than typically found in blood,the PRP injections after the initial surgery support the restoration of injured tissue in the knee and inhibit painful inflammatory processes.
This research was the first study which used clinical follow up data over more than 4 years and proves that cell therapy can promote the regeneration of articular cartilage in a lasting way. The study proved that the use of these intra articular injections of PBSCs with PRP regenerated articular cartilage improved the outcomes for knee chondral lesions.
Around 85% of all patients all returned to participating in sporting activities and saw clinically significant improvements. There was no deterioration of neoformed cartilage or any reoccurrence of the lesion at the follow up 5 years appointments. The tissue was of a higher quality.
Stem cell treatment is highly effective as the cells can be easily acquired and expanded, and used in cartilage injuries. In this research they have been extensively studied with promising results. They have a high capacity for self renewal, multipotentiality, and plasticity. This treatment of PRP into the knee can facilitate tissue healing, actually shows the capability for restorative healing, inflammation modulation and cartilage repair.
This study has proved the use of orthobiologics in common knee surgery and that the use of PRP delivers significantly better results at the 4 year follow up.
*Intra-articular administration of peripheral blood stem cells with platelet-rich plasma regenerated articular cartilage and improved clinical outcomes for knee chondral lesions
Published August 2019 https://www.thekneejournal.com/article/S0968-0160(19)30094-8/fulltext