Interventional Radiology

Most patients are surprised at how manageable the procedure is. Local anaesthetic is used to numb the skin and surrounding tissue before the main needle is inserted, so the most uncomfortable moment is typically the initial anaesthetic injection, which stings briefly for a few seconds.

Once the area is numb, the majority of patients feel only pressure, not pain, as the needle advances. Some deep structures (such as hip joint injections or spinal injections) may involve more awareness than superficial joints, but the local anaesthetic significantly reduces discomfort throughout.

If you feel significant pain at any point, let the radiologist know immediately and they can adjust their approach or administer additional anaesthetic.

This varies by patient and by what was injected. Local anaesthetic (which is often mixed with the corticosteroid) provides immediate but temporary relief lasting a few hours, this is a good sign that the needle was in the right place. Once the local anaesthetic wears off, pain may briefly return to its pre-injection level.

The corticosteroid itself begins working over 2-7 days, reaching its maximum anti-inflammatory effect at around 1-2 weeks. Most patients notice meaningful improvement within this period. The duration of relief varies widely from a few weeks to many months depending on the condition, its severity, and the individual patient.

You may also notice a temporary increase in pain in the 24-48 hours immediately after the procedure (a "steroid flare"). This is common and settles on its own. Ice and paracetamol can help.

As a general guide, corticosteroid injections into the same joint or structure are typically limited to two to three times per year, with at least 6-8 weeks between injections. This is because repeated corticosteroid exposure can, over time, weaken tendons and cartilage.

This limit is a precaution, not a rigid rule and your referring doctor and our radiologist will always consider your overall clinical picture. Some patients with severe arthritis may benefit from more frequent injections under specialist guidance. If you are experiencing rapid recurrence, this may indicate that a different treatment approach (physiotherapy, surgery, or viscosupplementation) should be explored.

Yes, a referral from a registered medical practitioner is required for all interventional procedures at Matrix Medical Imaging. Referrals can be provided by your GP, orthopaedic surgeon, rheumatologist, sports medicine doctor, pain specialist, or any other registered medical practitioner.

The referral should specify the site to be injected and the type of procedure requested (e.g., "left knee corticosteroid injection" or "right shoulder hydrodilatation"). If your referring doctor is unsure about the most appropriate procedure for your condition, they are welcome to call our clinic to speak with one of our radiologists.

Many common interventional procedures are covered by Medicare and bulk billed for eligible patients with a valid referral. However, not all procedures have a Medicare item number, and some specialised procedures may have an out-of-pocket cost.

Our reception staff will confirm whether your specific procedure is bulk billed, or advise you of any applicable gap fee, when you call to book. We recommend clarifying this before your appointment to avoid any surprises. Please bring your Medicare card and any concession or healthcare card on the day.

Yes, they are quite different in how they work. Euflexxa is a brand of hyaluronic acid (HA) a substance that naturally occurs in healthy joint fluid and gives it its lubricating, shock-absorbing properties. In an arthritic knee, this natural HA breaks down and becomes less effective. Injecting Euflexxa replenishes and supplements this fluid, improving joint lubrication and reducing pain.

Corticosteroid (cortisone) injections work by reducing inflammation. They typically act faster but may have a shorter duration of effect. Euflexxa is given as a course of three weekly injections. Relief may be slower to onset but can last 6-12 months in well selected patients.

The two treatments can sometimes be complementary, a cortisone injection may be used first to reduce acute pain, followed by a Euflexxa course to support longer-term joint function. Your referring doctor and our radiologist will advise which is most appropriate for your situation.

All medical procedures carry some degree of risk, but image-guided procedures at Matrix Medical Imaging are generally very safe. Common and expected effects include:

• Temporary soreness or bruising at the injection site (24-48 hours)
• a 'steroid flare' - increased pain for up to 48 hours before improvement begins
• Temporary skin flushing or feeling of warmth, particularly in the hours after a cortisone injection

Rare but possible complications include:

• Infection (very rare strict sterile technique is used throughout)
• Allergic reaction to local anaesthetic or corticosteroid
• Temporary blood sugar elevation in diabetic patients
• Skin pigmentation change or fat atrophy at the injection site (more common with very superficial cortisone injections)

Serious complications are exceptionally uncommon in image guided procedures performed by trained specialist radiologists. Our radiologist will discuss risks specific to your procedure before you consent.

For most peripheral joint injections (shoulder, knee, hip, elbow, ankle, wrist), you should be able to drive yourself home once the local anaesthetic effect has sufficiently worn off and you feel comfortable behind the wheel. However, we recommend waiting at the clinic for at least 15 minutes after your procedure before driving.

For spinal injections, particularly cervical (neck) injections, or any procedure where significant sedation is used, you should arrange for someone to drive you home. Our staff will advise you when you book if your specific procedure requires a driver. If in doubt, arrange a lift regardless it is always the safer option.