What is plasma and what are platelets?

Plasma is the liquid portion of whole blood. It is composed largely of water and proteins, and it provides a medium for red blood cells, white blood cells and platelets to circulate through the body. Platelets, also called thrombocytes, are blood cells that cause blood clots and other necessary growth healing functions.

Platelet activation plays a key role in the body’s natural healing process.

What is platelet-rich plasma (PRP) and what are PRP injections?

Platelet-rich plasma (PRP) is a growth factor rich medium that is developed from the patient’s blood. It is not synthetic.  PRP therapy uses injections of a concentration of a patient’s own platelets to accelerate the healing of injured tendons, ligaments, muscles and joints. In this way, PRP injections use each individual patient’s own healing system to improve musculoskeletal problems.

PRP injections are prepared by taking anywhere from one to a few tubes of your own blood and running it through a centrifuge to concentrate the platelets. These activated platelets are then injected directly into your injured or diseased body tissue. This releases growth factors that stimulate and increase the number of reparative cells your body produces.

Research has shown PRP to be effective in the management of early osteoarthritis (joint degeneration) and some tendon injuries.

How are PRP injections done? What is involved?

PRP therapy involves one (for tendons) or two injections (for joints) into the injured area a fortnight apart. On each occasion the patient will be required to donate blood for generation of the PRP.  Injections are done under sterile conditions, with local anaesthetic and using ultrasound guidance.  Each procedure will take approximately 30 minutes.

We published a research paper in 2022 showing that two injections of PRP for knee osteoarthritis reduces symptoms in the majority of cases. We also showed that three injections (or more) were not more effective than two.

What do I need to do before my injections?

Patients are required to cease taking anti-inflammatory tablets one week prior to the PRP procedure.  Patients taking regular aspirin should continue to take this.

What do I need to do after my injections?

It is recommended that someone drive the patient home after an injection due to some potential residual effects of the local anaesthetic or discomfort from the procedure. Depending on the structure injected, the patient may need to offload the area for a period. 

Patients undergoing PRP injections should also be actively involved in a supervised rehabilitation program.  In some instances, the patient may need to stop exercise for a period and resume after medical review.

Risks

In general, adverse outcomes from PRP injections are rare, but they may include:

Bleeding/Bruising/Infection

To reduce chance of infection all injections are done under sterile conditions using ultrasound guidance for accuracy. PRP has natural anti-bacterial properties that reduce chance of infection.

Pain/Discomfort

Injections can be uncomfortable. In all cases, local anaesthetic is used. Patients are encouraged to use simple analgesia (Panadol/Panadeine) as required after the procedure and icing can be very helpful.  If necessary, the doctor can provide a prescription for Panadeine Forte. Much of the post procedure discomfort can be addressed by closely following any post procedure instructions.

Contra-Indications

PRP injections are generally very safe, but are contra-indicated in the following conditions:

• Pregnancy
• Cancer
• Some bleeding disorders

Knee osteoarthritis (OA) is one of the most common and most costly issues facing our modern Australian population.

While knee replacement is often a very effective treatment for osteoarthritis pain, it is major surgery. Recent high-quality studies have shown that in some cases, knee arthroscopy (‘a clean-out’) may be no better (or even worse) than no treatment at all.

Between pain medications and surgery, there are injectable treatments that can improve knee pain and function. The most commonly used injections for knee OA fall into three categories: corticosteroids (“Cortisone”), hyaluronans (e.g. “Durolane” or “Synvisc”), and blood-derived injections (platelet rich plasma or “PRP”, and others).

Cortisone

Sometimes a knee may have some longstanding OA but has become suddenly more swollen and painful: in this situation a corticosteroid injection may settle the knee back to how it was beforehand. Corticosteroids are powerful anti-inflammatory drugs, but do not improve the overall cartilage health of a knee with OA, and care must be taken that there is no infection in the knee, as a cortisone injection may make this much worse.

Hyaluronans

Hyaluronans are synthetic versions of the natural fluid inside the knee joint. In a normal knee this fluid helps to lubricate the joint and to keep the cartilage healthy. In a knee with OA, the knee fluid is also damaged and does not protect the joint as it should. An injection of a synthetic hyaluronan replaces the unhealthy fluid. Over more than 25 years of use worldwide this has been found to be an effective means of improving knee pain and function. This works best in knees with mild rather than severe OA and is usually very well tolerated. Improvements are often seen to last for 12-18 months.

We use Durolane, which has virtually no risk of allergic reactions compared to Synvisc (about 2% risk). Another option is Cingal, which is a combination of hyaluronan and cortisone.

Platelet-Rich Plasma (PRP)

Blood-derived treatments aim to provide natural anti-inflammatory substances from the blood. Blood is taken from the patient (like for a blood test), and then treated to extract the chosen substances, before being injected back into the knee. PRP is the most studied version of these treatments and has been found to improve knee pain and function for 12-24 months.

At Ballarat Orthopaedics and Sports Medicine, we have the capacity to provide any of these treatments, and the experience and knowledge to help you choose which treatment is the best one for you.

Ballarat Sports Medicine has recently welcomed Peta Johnston to our team. Peta is an experienced Physiotherapist who graduated from the Bachelor of Physiotherapy with Honours at La Trobe University in 2006. Since graduating she has worked clinically as a physiotherapist throughout western Victoria including public and private hospital settings as well as private practice. She has significant caseload experience in many areas of Physiotherapy practice including: orthopaedic inpatients/outpatients, geriatric evaluation and management, and community rehabilitation. Peta is a member of the Australian Physiotherapy Association and is currently undertaking her PhD into outcomes following anterior cruciate ligament (ACL) reconstruction surgery. Peta strives to apply evidence-based practice to help improve movement patterns and functional performance and real-life outcomes for her clients.

Peta has commenced providing an after-hours Physiotherapy service at Ballarat Sports Medicine.

Point of care ultrasound (POCUS) has become increasingly important in many branches of medicine, from obstetrics to emergency medicine and anaesthetics. Technological advances in both ultrasound probes and connectivity have allowed for smaller machines that can provide images with as good a quality as the larger machines of 10 years ago. This means that ultrasound can be used in the rooms, or even at a footy club or sporting event.

In Sports Medicine we use ultrasound to guide many of our injections. Not all our injections need an ultrasound for guidance, but for some things it allows us to be sure we are treating exactly the right spot. Getting an injection under ultrasound guidance costs a bit more up front, but you get back more from Medicare.

Like with any tool, using an ultrasound requires training and practice. Our Sports Physicians spend time practicing and learning from experienced musculoskeletal sonographers (ultrasound technicians) to make sure their skills are up to date.