Ultrasound Guided Injections

Cortisone is a synthetic form of a Cortisol, a natural hormone your body produces. Cortisol is also called the “coping hormone” because it increases during times of stress and assists with regulating the immune system and energy systems to cope with the demands of life.

Cortisone (injectable corticosteroid) is a potent anti-inflammatory and tends to be useful to treat problems related to excessive inflammation. However, it the important thing to understand about cortisone is that it is a “catabolic steroid”. This is the opposite of “anabolic steroid”, meaning it tends to shrink everything down. It powerfully reduces inflammation- and this is good- but is also inhibits the signals around an injured area that assist healing. The first study to demonstrate the potential harmful effects was published by an Australian physio in 2000. Bisset (2006) showed that patients who were treated with a cortisone injection for tennis elbow had worse results that the patients who had no treatment (a wait and see approach).[1]

Because of this cortisone has a bad reputation for the treatment of chronic injuries, since this theoretical catabolic effect has now actually been shown to delay and worsen recovery.[2-4]

It still has a role for acute injuries where the inflammation is excessive, or in chronic injuries where the patient is willing to have short-term benefit with the knowledge that the problem is likely to return (e.g. going on an overseas holiday).

The skin is prepared using an antiseptic agent to reduce risk of infection.

The degree of discomfort during the procedure is generally mild as the needle used is fine (thin) and local anaesthetic is usually mixed in with cortisone.

The needle is then guided into the relevant body part using an ultrasound (unless the area being injected is very close to the skin and ultrasound wouldn’t help to prove the exact location of the injection). The guidance allows the cortisone to be accurately delivered into the area of suspected/proven pain.

Cortisone takes between 5-10 days to have its effect, because it gets inside cells and changes the way they express their genes and make proteins. Hence the messages take time to be realised.

If the underlying issue is not addressed cortisone is not effective in the long-term. It should be used to complement an overall management plan, and often is helpful in facilitating rehab exercises by reducing pain.

Where there is a lot of inflammation and swelling, cortisone is helpful.

• Simple ankle sprains with lots of swelling and pain
  
• The fat pad of the knee
  
• Inflamed bursa (sacs of lubricating fluid)- knee, elbow or elsewhere.
  
• Frozen or pinching (impinged) shoulder [6]
  
• Carpal tunnel syndrome [7]
  
• Nerve roots in the back (for “sciatica”) [8]
  
• Joint OA and tendon pain, when balancing the benefits and harms

You should avoid having a cortisone injection into a chronic tendon injury like tennis elbow or plantar fasciitis.[3,5] There are better, less harmful options to treat these.

The risks of cortisone injection are the same as for any injection into a joint- namely- infection and bleeding. These are both in the order of 1 in 80,000 injections. After a cortisone injection and once the local anaesthetic wears off (2-4 hours) there may be a temporary flare in pain for the first 24-48 hours, and this usually responds well to ice and rest. If pain at the site persists beyond this time, please return for medical review.

Generalised symptoms may also occur including facial flushing, mood disturbance, sleep disturbance and menstrual disturbance. These are uncommon, short-lived and resolve spontaneously, but if you have had the response previously, then there is a higher chance of recurrence. Localised skin depigmentation (lightening of colour) may occur with shallow injections, especially in patients with darker skin. Tendon rupture can occur with cortisone injections directly into a tendon, and this should be avoided.

You should plan to rest the injected are for 5-7 days (strictly for 24 hours) following the injection. Depending on the site of injection, this rest may involve getting driven to and from your appointment, wearing a protective sling, boot or other device.

There are definitely options that can be used instead – cortisone is never compulsory. Cortisone is generally used for treating pain, with the aim of facilitating improved function and the ability to maintain strength. There are many other options targeting the mechanical (e.g. strengthening of the surrounding muscles, appropriate footwear and activity choices) and chemical (e.g. anti-inflammatory medications both oral and topical) causes for the pain that should be addressed first.