PRP Injection for Knee Pain | Platelet Rich Plasma Guide

Chronic knee pain changes how you live. It’s the walk you shorten, the sport you give up, the stairs you dread. For many patients caught between ongoing pain and reluctance to pursue surgery, PRP therapy offers a middle path worth exploring.

Platelet Rich Plasma (PRP) is not a new or experimental treatment. It’s been used in sports medicine and orthopaedics for over two decades. At Manningham General Practice, our doctors with a special interest in musculoskeletal medicine provide PRP injections using ultrasound guidance for precision and safety.

What Is Platelet Rich Plasma (PRP)?

PRP is prepared from your own blood. A small blood sample is drawn and placed in a centrifuge, which spins at high speed to separate and concentrate the platelets. Platelets contain growth factors — proteins that play a central role in tissue repair and regeneration. The concentrated platelet-rich portion is then injected directly into the affected joint or tendon.

Because PRP is derived from your own blood, the risk of allergic reaction or rejection is minimal. The goal is to accelerate the body’s own healing response in an area that typically has poor blood supply — like cartilage and tendon tissue.

What Conditions Is PRP Used For?

PRP therapy is most commonly used to treat musculoskeletal conditions where healing is slow or incomplete:

• Knee osteoarthritis — particularly mild to moderate OA where pain is limiting daily activity
• Tennis elbow (lateral epicondylitis) — chronic tendon pain on the outside of the elbow
• Achilles tendinopathy — persistent pain at the back of the heel
• Rotator cuff injuries — shoulder tendon damage from overuse or injury
• Plantar fasciitis — heel pain caused by inflammation of the plantar fascia
• Patellar tendinopathy — “jumper’s knee” pain below the kneecap

Is PRP Effective? What Does the Research Say?

The evidence for PRP is strongest for knee osteoarthritis and certain tendinopathies. Multiple randomised controlled trials and systematic reviews have found PRP to be at least as effective as, and in some studies superior to, corticosteroid injections for reducing knee pain over the medium to long term — particularly in early-to-moderate osteoarthritis.

It’s important to be honest: the evidence varies by condition. PRP for chronic low back pain and some rotator cuff tears shows less consistent results. Your GP will have a frank conversation with you about whether the evidence supports PRP for your specific diagnosis before recommending it. For some patients, a corticosteroid injection may be a more appropriate first-line option.

What Happens During a PRP Injection at MGP?

1. Initial evaluation: Your GP assesses your condition, reviews any imaging (X-ray, MRI, ultrasound), and determines whether PRP is the appropriate treatment.
2. Blood draw: Approximately 15–30mL of blood is taken from your arm, similar to a standard blood test.
3. Centrifuge processing: The blood is spun in the centrifuge for approximately 15 minutes to concentrate the platelets.
4. Ultrasound-guided injection: The PRP is injected under ultrasound guidance directly into the affected joint or tendon — ensuring precision placement for maximum effect.
5. Recovery and review: You’ll be monitored briefly after the procedure. A follow-up appointment is recommended to assess your response and plan any additional treatment.

PRP vs Corticosteroid Injection

Feature	PRP Injection	Corticosteroid (Cortisone)
Primary mechanism	Stimulates natural healing via growth factors	Reduces inflammation directly
Speed of relief	Gradual — weeks to months	Often rapid — days to weeks
Duration of effect	Potentially longer-lasting	Typically weeks to months
Medicare coverage	No — privately funded	Rebate may apply — discuss with GP
Best suited for	Tendinopathy, moderate OA, healing support	Acute inflammation, short-term pain relief
Repeat injections	A course may be recommended	Usually limited (cartilage concerns with repeated use)

Recovery After a PRP Injection

Expect some soreness at the injection site for 2 to 5 days after the procedure — this is a normal part of the healing response being triggered. You’ll be advised to:

• Rest the affected area for 24 to 48 hours
• Avoid anti-inflammatory medications (NSAIDs) for at least 2 weeks after the injection, as they may blunt the healing response PRP is designed to trigger
• Gradually resume normal activity as guided by your doctor
• Consider physiotherapy alongside PRP to maximise outcomes

Improvement is gradual. Most patients begin noticing benefit at 4 to 8 weeks, with peak results often seen at 3 to 6 months. MGP’s musculoskeletal clinic can provide ongoing monitoring and support throughout your recovery.

Frequently Asked Questions

How long does a PRP injection appointment take?

Allow approximately one hour in total. The blood draw and centrifuge process takes around 30 minutes, and the injection itself is quick. You’ll be monitored briefly afterwards.

Is a PRP injection painful?

Most patients experience mild discomfort at the injection site. Local anaesthesia is often used to minimise pain. Post-procedure soreness is common and usually settles within a few days.

Is PRP covered by Medicare or private health insurance in Australia?

PRP is not currently covered by Medicare or most private health funds. Costs are discussed at your consultation. Contact MGP on (03) 8840 1400 for current pricing.

How long before I notice results from a PRP injection?

Results typically develop gradually over 4 to 8 weeks. Some patients notice improvement earlier; full benefit may take 3 to 6 months.

How many PRP injections will I need?

This depends on your condition and your response to the first injection. Your doctor will discuss the recommended course at your initial evaluation.

Can anyone have a PRP injection?

PRP is suitable for most people, but is not recommended for those with certain blood or platelet disorders, active infections, or who are pregnant. Your doctor will assess suitability at your initial consultation.

Do I need an MRI or imaging before a PRP injection?

Your doctor may request imaging to confirm the diagnosis. Ultrasound guidance is used during the injection itself for precision placement.