Your knee injection
Information about your planned knee joint injection. Please read it carefully and use it as a starting point for discussion with your healthcare team.
What is a knee injection?
A common, minimally invasive procedure in which medicine is injected directly into the knee joint. It is usually done in clinic and takes a few minutes.
Before your injection
Please tell us if you take blood-thinning medicines, have diabetes, have any infection or feel unwell, or could be pregnant. Bring a list of your medicines with you.
The procedure
- Preparation: the skin over the knee is cleaned with antiseptic.
- Injection: a fine needle is passed into the knee joint and a mixture of local anaesthetic and steroid is slowly injected (you may feel a brief sting or pressure).
- Finish: the needle is removed and a small plaster applied.
The medicines and what to expect
| Medicine | What it does | Effect |
|---|---|---|
| Local anaesthetic | Numbs | Immediate pain relief, wearing off after about 6 hours. |
| Steroid (corticosteroid) | Strong anti-inflammatory | Takes 1 to 2 weeks to start working; can give longer-term pain relief lasting weeks or months. |
Note: results vary a great deal from one person to another.
If you are thinking about a knee replacement: surgery on the same knee is usually put off for about three months after a steroid injection, because operating sooner is thought to increase the risk of infection.
Benefits
- Targeted pain relief and reduced inflammation.
- Helps confirm whether the knee joint is the source of your pain.
- A steroid injection can relieve pain for weeks or months for some people. It does not slow the arthritis, and for some people it does not help.
Possible risks and side effects
- A temporary flare of pain for 24 to 48 hours after the local anaesthetic wears off.
- Bruising where the needle went in.
- Infection (very rare). Please see a doctor urgently if the joint becomes hot, red, swollen or very painful.
- Steroid side effects: a flushed face, changes in the colour or thickness of the skin where the needle went in, and weakening of the tendons. Repeated injections raise these risks.
- Allergic reaction to the medicines (rare).
- Raised blood sugar for a few days if you have diabetes; monitor it closely.
After your injection
| Driving | You may be able to drive after a knee injection. Check with your insurer, and do not drive if your knee feels numb or weak. |
|---|---|
| Normal activities | Resume light, normal activities as soon as you feel safe and comfortable. |
| Strenuous activity | Avoid strenuous activity or heavy exercise for at least 24 to 48 hours to let the steroid settle. |
| Urgent advice | Seek urgent medical advice if you develop a high fever, severe pain after 48 hours, or increasing redness, swelling or discharge where the needle went in (possible infection). |
If you have any further questions, please discuss them with me or any member of the healthcare team. See the contact page.