Corticosteroid Injection

What is it?

A corticosteroid injection places an anti-inflammatory medicine into or around a painful or swollen joint. It can also go into soft tissue, such as a tendon sheath (the covering around a tendon) or a bursa (a small fluid-filled cushion near a joint). Common medicines include hydrocortisone, triamcinolone and methylprednisolone.

The steroid acts like cortisol, a hormone your body makes naturally. It calms your immune system in that spot, which reduces inflammation, pain, swelling and stiffness. A local anaesthetic is often added to numb the area for a short time.

What is it used for?

Injections are used for osteoarthritis (wear in a joint), bursitis, tendon and tendon-sheath problems, frozen shoulder, trigger finger and de Quervain disease (pain at the thumb side of the wrist). They are also used for flare-ups of inflammatory arthritis. How well they work depends on the condition.

The clearest results are for trigger finger, where an injection is much more likely to help than a dummy (placebo) injection. For frozen shoulder, an injection gives more short-term pain relief than no treatment or physiotherapy. For knee and hip osteoarthritis, an arthritis guideline strongly recommends injections, and for hand osteoarthritis it recommends them with less strength. For de Quervain disease, injection is often used, and as many as 83 per cent of people are reported to get pain relief.

For tendon problems such as tennis elbow and rotator cuff tendinopathy (a painful shoulder tendon), the picture is less positive. Injection can give short-term relief, but it is not clearly better than exercise or physiotherapy over the longer term. Bursitis and tendon-sheath inflammation are also listed as conditions where an injection may help.

Injections are sometimes suggested for plantar heel pain (pain under the heel). It isn't yet clear how well they work for it, so ask your podiatrist about your other options.

Is it right for me?

An injection suits people whose doctor thinks they are likely to benefit. It may not always help, so your doctor will assess you first. They will also check for anything that would make an injection unsuitable, such as high blood pressure, heart disease, heart failure, a risk of stomach bleeding or kidney disease.

For frozen shoulder, an injection can be offered early, after the risks and other options are explained. Frozen shoulder usually lasts a few months but can take more than a year to settle, and an injection may speed it up.

An injection is usually put off if you:

• have an infection in the area or anywhere else in your body, a fever, or feel unwell
• have a skin problem, such as an infection, where the needle would go
• are allergic to the steroid or the local anaesthetic
• have surgery planned soon in that area
• have poorly controlled diabetes
• are pregnant or breastfeeding
• don't want the injection

For knee injections, uncontrolled high blood pressure, an active stomach ulcer, epilepsy and some other brain and mental health conditions, or a broken bone in or next to the joint, are also reasons not to inject.

Take extra care and tell your doctor if you have diabetes, if your immune system is weakened, or if you have recently had or are about to have a vaccination. Children may not be suitable, so a specialist should advise first.

What happens?

Steroid injections are available only on prescription. They are usually given by a specially trained doctor in a GP surgery or hospital clinic. The doctor should use a very clean (aseptic) technique and never inject through an infected area.

Sometimes the doctor uses ultrasound (a scan that shows the inside of your body) to guide the needle. This places the medicine more accurately than feeling for landmarks. It helps most in small joints, and it is strongly recommended for the hip. It isn't needed for knee and hand joints, but it may help. Guidance can also help when the person injecting is less experienced in landmark techniques.

The local anaesthetic gives relief for a few hours. After that, the steroid takes a little time to start working.

How well does it work?

Most people notice relief within a few days, often within 24 to 48 hours. For some it takes days to weeks. The relief usually lasts a few weeks to several months. It varies from person to person, and a few people get no benefit.

An injection gives short-term pain relief, not a lasting cure. How long the benefit lasts depends on the condition:

• Knee osteoarthritis: pain relief is greatest in the first few weeks. It is small by 13 weeks and not clear by 26 weeks. Repeated knee injections have not been better than a saline (salt water) injection for pain, and they were linked to more loss of cartilage (the smooth cushioning on the ends of your bones).
• Frozen shoulder: the edge over other non-surgical treatments appeared to last up to six months, though some differences between groups had gone by 26 weeks.
• Tennis elbow: relief lasts under 8 weeks. After a year, fewer people had recovered than with a placebo injection (83 per cent compared with 96 per cent), and more had the pain come back (54 per cent compared with 12 per cent). Physiotherapy did better over the long term.
• Rotator cuff tendinopathy: an injection was no better than physiotherapy at the medium and longer term.
• Gluteal tendinopathy (a painful hip tendon): learning how to manage load on the tendon, plus exercise, did better than an injection at 8 months.

For tendon problems, an injection is best seen as one part of a wider plan, not a stand-alone fix.

Risks and side effects

The common effects are short-lived. Once the local anaesthetic wears off, you may have mild pain, called a steroid flare, for 24 to 48 hours until the steroid takes effect. Your blood sugar can rise for a few days, especially if you have diabetes. If you have high blood pressure, it may rise for a short time.

Serious problems are rare:

• Joint infection: about 1 in 10,000 procedures. It is serious and is treated with antibiotics through a drip in hospital.
• Infection after keyhole surgery (arthroscopy): this is more likely if you have an injection close to the operation. Tell your surgical team about any recent injection, and tell your doctor if surgery is planned.
• Allergic reaction: very rare, and usually within minutes of the injection.
• Tendon or ligament rupture: rare, and more likely with repeated injections.
• Cartilage loss: seen with repeated knee injections.

See the warning signs at the end of this page for when to get help.

Afterwards

Expect your area to feel numb for a few hours. Pain may come back for a day or two before the steroid starts to work. If you have diabetes, check your blood glucose for 48 hours and act on the results as your doctor has advised. Seek medical advice if your glucose can't be controlled.

If the injection gives you a pain-free window, use it to start or build up your exercises or load management, because these help with the longer-term recovery. Ask your doctor for written aftercare advice, including who to contact.

If your symptoms aren't improving or are getting worse, your plan needs a review. Tell your practitioner, so you can look at the other options.

When to see a podiatrist

Book an appointment if

You are wondering whether an injection is right for your foot or other pain, you have had an injection and your symptoms aren't improving or are getting worse, or the pain keeps coming back once the relief wears off.

Seek prompt assessment if

you get an allergic reaction after an injection, with a rash, wheeze, difficulty breathing, or swelling of your face or tongue: call your local emergency number straight away. If you have a red, hot, swollen injected area and also feel very unwell, with confusion or slurred speech, severe shivering or muscle pain, severe breathlessness, mottled or discoloured skin, or little or no urine, this could be sepsis: call your local emergency number. See your GP or another doctor today if the injected area becomes red, hot and swollen, you have a fever or feel unwell, you have severe pain, or you have trouble moving the area. Do the same if you have sudden severe joint pain and can't move the joint or put weight on it, especially with hot, swollen or red skin: a joint infection can cause this, and fever may be absent. If your GP can't see you today, go to an urgent care clinic or an after-hours GP. Contact the person who gave your injection or your GP if the area stays hot, swollen or painful for more than 24 hours, or if you feel generally unwell. See your GP soon if you have diabetes and can't keep your blood glucose under control after an injection.

Frequently asked questions

Is a corticosteroid the same as an anabolic steroid?

No. A corticosteroid is an anti-inflammatory medicine that works like cortisol, a hormone your body makes naturally. It is not the same as the anabolic steroids used to build muscle. Because it is injected into one area, it is aimed at a single painful spot.

Can I have an injection if I take blood thinners?

Possibly, but tell the doctor who is injecting before you have it. People on blood thinners have a slightly higher risk of bleeding. Your doctor will weigh this up. Don't stop any medicine unless your doctor tells you to.

How many injections can I have in one joint?

It isn't clear yet how many injections, or how far apart, are best. Repeating them has downsides, so your doctor will look at how much each one helped before suggesting another. If an injection hasn't helped, ask about other options rather than simply repeating it.

Further reading

• Guided Therapeutic Injection in the Ultrasound Dept NHS
• Local Steroid Injection NHS
• Musculoskeletal injection treatment NHS
• Common questions about hydrocortisone injections NHS
• Steroid injection referral guide :: Mersey Care NHS Foundation Trust NHS