We are very fortunate to have Dr Ken Cameron and Dr John Ward practicing in our clinic.
Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets.
As a concentrated source of autologous platelets, PRP contains (and releases through degranulation) several different growth factors and other cytokines that stimulate healing of bone and soft tissue.
The efficacy of certain growth factors in healing various injuries and the concentrations of these growth factors found within PRP are the theoretical basis for the use of PRP in tissue repair. The platelets collected in PRP are activated by the addition of thrombin and calcium chloride, which induces the release of the mentioned factors from alpha granules. The growth factors and other cytokines present in PRP include:
- platelet-derived growth factor beta
transforming growth factor beta
fibroblast growth factor
insulin-like growth factor 1
insulin-like growth factor 2
vascular endothelial growth factor
epidermal growth factor
keratinocyte growth factor
connective tissue growth factor
The creation and injection of PRP takes about 30 minutes, is an outpatient procedure, and is undertaken by a medical doctor.
Prior to the procedure, your doctor will ask you some questions about your condition and general health. Active skin infections at the the injection site or platelet disorders are contra-indications.
Please bring any x-rays and scans you have of your condition.
There is no need to fast prior, in fact it is best if you drink lots of water before coming. Wearing loose clothing that allows easy exposure of the knees or tendon injury site is recommended.
PRP Injection Procedure
The procedure involves drawing blood from your arm which is placed into a special tube containing a separating gel, just a like a regular blood test.
The tube is then spun in a centrifuge and the PRP is separated from the red blood cells by the gel.
The PRP layer is then collected into a syringe for injection.
The area to be injected is first numbed with local anesthetic, then the PRP is injected into the area of concern.
After the injections, strenuous exercise is best avoided for 24 hours, as is excessive alcohol.
Keep the injection site clean and dry for 24 hours.
The benefits of the PRP should be noticed about 4-8 weeks after the first injection.
As the PRP injection activates the immune system there can be significant pain for the following week after injection, so plan to have pain relief available and time off work if required.
Common adverse effects can include pain for 24-48 hours or swelling & bruising at either injection site, and occasionally this can last a week or more. Apply ice for few hours after if you experience pain at the injection site. To avoid skin “cold burn”, wrap the ice in a towel to avoid direct skin contact and use for 20 minutes on, 20 minutes off.
Uncommon or rare adverse effects include dizziness, nausea or feeling generally unwell.
Severe complications, such as infection are very rare. If you suffer worsening knee pain and swelling after 48 hours post-injection, please seek medical advice urgently. Pain, swelling or skin redness in the first 48 hours post injection is very rarely an infection, and usually due to post-injection inflammation.
While these side effects are uncommon, it’s best to plan a more flexible work schedule in the few days after the injection in case you do suffer some pain or swelling for a few days.
Avoid suddenly increasing your activity as your knee starts to feel better, rather slowly increase activity over a few weeks.
Effectiveness of PRP
PRP injections for joint osteoarthritis and musculoskeletal conditions are variable in there effectiveness. Some studies suggest that when PRP is injected into an arthritic knee, patients can expect improved pain and function for 6 – 12 months. Some studies also suggest 80% of patients experience significantly reduced pain & stiffness, with improved function for 6-12 months. Hence if you suffer moderate pain, it will reduce to mild, mild to none and severe to moderate. The less severe the osteoarthritis, the longer the effect. Some patients will still have reduced pain for up to 2 years.
A second injection is usually recommended about 4 weeks later, with top-up injections depending on symptoms at 6, 12 or 24 months. The second injection is recommended to lengthen the period of pain relief. There is some evidence that PRP helps the new cartilage formation significantly.
The use and clinical validation of PRP is still in the early stages, but clinical experience has shown that 70 – 80% of patients will feel an improvement after 1 injection.
While scientific evidence is mounting on a regular basis as to the benefits of PRP over other injectable options, it is not a miracle cure. Not all patients respond, and the effect fades with time. PRP injection will work best in conjunction with other treatments such as physiotherapy.