Will blood injection platelet therapy help my damaged knee cartilage?

Q: I'm on a search for myself. I have damaged knee cartilage that lines the joint and I need help. So far, I've tried six months of diet and exercise to take pressure off the knee and improve my strength. The weight loss has been great but the knee still hurt. Then I let the surgeon shave the joint. That's supposed to help too. But I still feel like an old man with this gimpy, painful knee. What about this new blood injection platelet therapy? Can I try that if I've already had the knee scraped?

A: Platelet-rich plasma (PRP) (also known as blood injection therapy) is a medical treatment being used for a wide range of musculoskeletal problems. PRP refers to a sample of serum (blood) plasma that has as much as four times more than the normal amount of platelets. This treatment enhances the body’s natural ability to heal itself and is used to improve healing and shorten recovery time from acute and chronic soft tissue injuries.

Using platelet-rich plasma to encourage tissue regeneration in the hyaline cartilage of the knee may be a new way to prevent or slow down the degenerative process that leads to osteoarthritis. Hyaline tissue is the type of cartilage that lines the inside of the knee joint.

The hyaline cartilage has many wonderful characteristics. It allows the knee joint to move without friction. It protects the bone underneath the cartilage from too much load and trauma. Hyaline cartilage also spreads out the forces placed on the knee joint during movement. But the one thing it does not have is a rich supply of blood. Injury or damage to the hyaline cartilage sets off a series of events that can lead to degeneration and osteoarthritis.

That's where platelet-rich plasma comes in. It has been used for years after plastic surgery and surgery on the mouth, jaw, and neck. It seems to promote and speed up healing. Anywhere from two to six times the number of platelets with their growth factors are released into the injured area.

Blood injection therapy of this type has been used for knee osteoarthritis, degenerative cartilage, spinal fusion, bone fractures that don’t heal, and poor wound healing. This treatment technique is fairly new in the sports medicine treatment of musculoskeletal problems, but gaining popularity quickly.

In a recent study from the OASI Bioresearch Foundation in Milan, Italy, two groups of patients with osteoarthritis of the knee were given two injections of platelet-rich plasma (PRP). Conservative (nonoperative care) with anti-inflammatory medications had been tried for at least three months with no improvement in symptoms.

One group (25 patients) had previous surgery for the damaged knee cartilage (either a shaving procedure called debridement or a procedure called microfracture). Microfracture is the use of tiny holes drilled through the cartilage and bone to stimulate bleeding and healing. The other group (25 patients) did not have any knee surgery prior to the blood injection therapy.

Results for the two groups were compared by looking at pain, function, and quality of life. A variety of tests were used to collect information to measure these outcomes. All measures were taken before platelet-rich plasma injection (baseline), six months after the injections, and again one-year after injection therapy. Results were also compared between men and women to see if there was a sex-linked difference in treatment results.

They found no difference in results between the two groups or between the sexes. It seems everyone in the study benefitted and improved with this treatment approach. There was a positive effect of PRP in active patients with painful knee osteoarthritis. There were no differences between men and women and no adverse reactions or complications for anyone.

This study provides some evidence that using platelet-rich plasma (PRP) to stimulate the natural healing process and regenerate hyaline cartilage may be an acceptable way to treat the damaged hyaline joint cartilage you have. This is true even for patients (also like you) who have already had cartilage surgery (cartilage shaving or microfracture).

The authors point out that they used two PRP injections but there may be a more optimal number of injections required. Further research is needed to develop specific standardized treatment protocols. Likewise, studies are needed to find ways to predict how much PRP is needed for each type of tissue damage. Long-term studies (following patients for more than 12 months) are recommended.

Talk to your surgeon about this treatment. See if you might be a good candidate for platelet-rich plasma injection. This is a relatively new procedure and not all surgeons are trained in this technique. You may have to seek a referral elsewhere if it looks like you might benefit from platelet-rich plasma injection and your surgeon does not provide this type of treatment.

Reference: Alberto Gobbi, MD, et al. Platelet-Rich Plasma Treatment in Symptomatic Patients with Knee Osteoarthritis: Preliminary Results in a Group of Active Patients. In Sports Health. March/April 2012. Vol. 4. No. 2. Pp. 162-172.

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