What are the different types of injections used in knee and hip osteoarthritis?

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What are Cortisone/Corticosteroid injections?                

Figure 1: Hip and Knee Osteoarthritis - Injections - Physio Frenchs Forest, Physio Macquarie Park

Corticosteroids is a synthetic version of the natural hormone cortisol. Cortisone is an anti0inflammaotry drug that is injected into the painful site in an attempt to reduce any inflammation. Often a local anaesthetic is injected at the same time which is why lots of patients have instant relief. The drug is administered by a Surgeon, Sports Doctor or Radiologist.

What are Synvisc/Hyaluronic Acid (HA) injections?

Synovial fluid is found within the joints of the body. Its role is to lubricate the joint surface and allow an ease of movement. The aim of this injection is to provide properties of the joint fluid and thus allow better shock absorption and lubrication.

What are Platelet-Rich-Plasma (PRP) injections?

PRP injections are made from a blood sample which is rich in platelets. Blood is first removed and spun in a centrifuge to separation the components of the blood and then re-injected into the body. The plasma is filled with high levels of platelets and these allow the body to heal.

Do injections work?

The Royal Australian College of General Practitioners currently recommend the following for hip and knee osteoarthritis:

- Corticostertoid = Recommended

- PRP = Neutral recommendation

- Viscosupplementation/Synvisc = Recommended against

Which one do you choose?

All injuries are different in nature, and how we respond to treatment varies. Ease of availability and cost should be taken into account. When these factors are taken into account a corticosteroid is possibly the best option. 

Figure 2: Hip and Knee Osteoarthritis - Injections - Physio Frenchs Forest, Physio Macquarie Park

What does the evidence say about injections?

A meta-analysis of 34 randomised control trials looked at knee osteoarthritis and found the following:

- PRP was better than placebo at 12 months follow-up

- PRP was better than Synvisc at 6 and 12 months.

- PRP was favourable over steroids

- No evidence PRP was better in the first 3 months.

Take home message:

- There is some positive evidence that injections can be effective in reducing knee pain

- PRP appears the most effective type of injection for long-term pain relief

- The gold standard treatment for knee and hip osteoarthritis is exercise and weight loss

See our expert Physiotherapy team at Frenchs Forest and Macquarie Park!