Knee injection is a type of procedure in which medications are injected into the knee joint to treat the pain. Types of injections include steroid shots and hyaluronic acid injections. A steroid shot, (or a cortisone knee shot), works by immediately reducing inflammation in your joint. Hyaluronic acid is normally present in healthy knee joints and helps lubricate them. However, people with osteoarthritis (joint inflammation) generally lack enough amounts of this gel-like, elastic fluid in their joints.

Steroid injections are safe if used in appropriate doses. These injections are a common treatment for arthritis, tendonitis, and muscle and joint inflammation. To cure arthritis pain, the dosage of injections shouldn’t be more than four injections every 12 months.

Nevertheless, potential side effects can happen with larger doses and frequent use. Repeated steroid injections can cause arthritis aggravation, weakening of the tendons and bones, and gradual damage to the joint and its cartilage. Hence, their frequent use should be restricted.

We have many skillful specialists that can painlessly perform this procedure. However, you can feel a slight discomfort at the injection site. By necessity, the doctor may inject a syringe into the knee joint and remove a small amount of joint fluid. It will alleviate the pressure and pain in the knee.

Depending on the procedure type, it may take a few days or weeks for you to feel the effect of the injection. The physical nuances of a person also impact the symptom’s improvement. Some people feel instant relief while others should wait a few days. Hyaluronic acid injections, on the other hand, don’t offer instant benefits. Their effects begin roughly around the fourth week, with the maximum pain relief noted by the eighth week.

The effect of a steroid shot usually lasts from 6 to 12 months. The extent of the inflammation and overall health play a vital role in the duration of the injection effects. If you pair the injection with physical therapy or other rehabilitation treatments the relief can be prolonged.

Different outcomes depend on the kind of issue and the injection type. Steroid injections help promptly relieve knee pain and inflammation. You may feel a temporal “steroid flare-up” in pain that can last two days following the injection. Afterward, the discomfort in your joint will reduce, giving you long-standing pain relief. Pain relief can recover your foot functions that have been impaired by inflammation. Another type of knee injection called visco-supplementation injection involves injecting a gel-like fluid called hyaluronic acid into the inflamed knee joint. With this knee injection, you may not feel any immediate benefit. Many patients report some pain relief after several weeks of the course of injections, while others may benefit even months after the first injection. Most patients experience the most significant pain relief between 8 to 12 weeks after starting the treatment. Moreover, you may experience some swelling, heat, redness, itching, rash, bruising around your joint, and a build-up of fluid in your treated knee. These reactions are usually mild and transient.

If there aren’t any issues after the procedure, you are free to go home. You may be advised to:

• Avoid strenuous activity for the next 48 hours, including swimming or running
• Do not take hot tubs
• Avoid exposure to something that can carry infection through the needle track for the next 24 hours
• Monitor for side effects, such as an allergic reaction or an infection
• Take pain relief medication if you feel discomfort

Light activities, like walking, are allowed.

Recovery after a steroid shot does not take much time. It’s highly advised to take a break for at least 24 hours. Resting the joint after the injection is important to allow the inflammation to lessen. Exercises that can strain the joint should be avoided for several days after the injection. It’s best to stay active once you can exercise without feeling the discomfort or pain. However, it’s dangerous to overexert. Overexertion can damage your knee joint, making the whole steroid injection treatment useless.

It’s okay to take a shower the same day. But, it is best to not take a bath, a hot tub, or go to a sauna or pool for at least 48 hours after the injection.

All insurance providers cover steroid injections to some degree depending on policy from 50% to 100%.

JOINT CORTICOSTEROID INJECTION

Patient information: Depo-Medrone (methylprednisolone acetate) with lignocaine (local anaesthetic)

Dr John J. Ryan, MD
Sports Medicine Physician
Fitzwilliam Square, Dublin

Purpose of this sheet
This guide explains why a steroid injection may be offered for shoulder or knee pain, what to expect afterwards, possible risks, and when to seek help. It supplements—not replaces—the discussion with your treating clinician and the consent process.

1. What is the injection?

Depo-Medrone contains methylprednisolone acetate, a corticosteroid medicine that reduces inflammation. It is injected into a joint or, when clinically appropriate, into a nearby inflamed structure such as a bursa. Lignocaine (also called lidocaine) is a local anaesthetic that can numb the area for a short time and may give early relief. The exact site, dose, and whether lignocaine is suitable depend on your diagnosis, examination, medical history and the product being used.

The term “80 mg injection” describes the steroid dose that may be selected for some larger-joint or peri-articular problems; it is not the right dose for every joint or every patient. The product concentration and formulation matter. Your clinician will confirm the preparation, dose and route before treatment. A steroid injection is not a general cure for every cause of joint pain and is not suitable when infection is suspected.

2. Why might an injection be recommended?

A corticosteroid injection may be considered when pain and inflammation are limiting sleep, daily activities, work, rehabilitation or sport, particularly when examination and investigations suggest an inflammatory component. It may be used alongside an overall treatment plan that can include activity modification, physiotherapy, strengthening, weight management where relevant, and appropriate pain relief.

• Reduce inflammation: the steroid may calm inflammation in the joint lining or an inflamed bursa, reducing pain and swelling.
• Improve movement and function: less pain may make it easier to dress, reach, walk, climb stairs or take part in rehabilitation.
• Support rehabilitation: a period of symptom relief may help you perform prescribed mobility and strengthening exercises more comfortably.
• Potentially improve sleep and daily comfort: where pain is the main cause of night waking or activity limitation, improvement may help.

The response varies. Some people experience substantial relief, some partial or short-lived relief, and others little or no benefit. The injection does not repair a torn tendon, replace missing cartilage, reverse osteoarthritis or correct an underlying mechanical problem. Its main role is to reduce symptoms from a steroid-responsive source of inflammation.

3. Shoulder pain: what may improve?

Shoulder pain can arise from several structures, including the rotator cuff tendons, subacromial bursa, glenohumeral joint or acromioclavicular joint. An injection may be considered for selected conditions—for example, a painful inflamed bursa or some forms of inflammatory joint pain—after clinical assessment. The correct target matters: an injection into the joint is not the same as an injection around a bursa or tendon.

If the injection helps, you may notice less pain when lifting your arm, reaching overhead, putting on a jacket or lying on the affected side. The improvement may allow you to progress with a tailored physiotherapy programme. Gentle movement is usually preferable to keeping the shoulder completely still, but heavy lifting, repetitive overhead work and sport should be reintroduced gradually in line with advice.

Not all shoulder pain responds to steroid. A major rotator cuff tear, frozen shoulder, significant arthritis, referred neck pain or another diagnosis may need a different treatment strategy. If pain or weakness persists, your clinician may reassess the diagnosis and consider imaging or specialist referral where appropriate.

4. Knee pain: what may improve?

For the knee, an injection may be considered when inflammation within the joint contributes to pain and swelling, including in selected cases of osteoarthritis with an inflammatory flare or inflammatory arthritis. It may reduce discomfort, stiffness and swelling for a period and help you walk, manage stairs or take part in strengthening exercises more comfortably.

The injection does not regrow cartilage or correct meniscal damage, ligament instability or a change in the mechanics of the knee. A painful, hot, very swollen knee—especially with fever or feeling unwell—needs urgent assessment to exclude infection or another acute condition; it should not simply be treated with a steroid injection.

After symptoms settle, gradual quadriceps, hip and balance strengthening can help improve function. Avoid using early pain relief as a signal to immediately return to running, jumping, heavy leg training or a full sports workload. A sudden increase in activity may aggravate the underlying condition.

5. When will it start working, and how long can relief last?

Lignocaine may begin to numb the area within minutes, but this effect is temporary and usually wears off over a few hours. Early relief from the anaesthetic does not predict with certainty how well the steroid will work. As the anaesthetic fades, the original pain may return.

The corticosteroid effect is slower. Some people notice improvement within 24–72 hours; for others it can take several days, and occasionally around a week or longer. There can be a short-lived increase in soreness during the first 24–48 hours. The duration of benefit is variable: it may last weeks or months in some people, a shorter time in others, or there may be no meaningful benefit.

There is no guaranteed timeline. The result depends on the diagnosis, severity and duration of the problem, the accuracy of injection placement, activity after the procedure and individual response. If there is no improvement after about 7–14 days, contact the clinic for advice rather than assuming that another injection is automatically required.

6. What should I do after the injection?

• Take it relatively easy for the first 24–48 hours. Avoid strenuous exercise, heavy lifting and sport involving the treated joint during this period, unless your clinician gives different instructions.
• Keep the area clean and follow any dressing advice. A small dressing can usually be removed according to the instructions given at the appointment.
• Move the joint gently within comfort. Avoid prolonged complete immobilisation unless specifically advised.
• Return to normal activity gradually as pain allows. Follow the rehabilitation plan provided; do not use temporary pain relief to push through significant pain.
• If you have diabetes, monitor your blood glucose more closely for several days after the injection, as steroid can temporarily raise it. Follow your usual diabetes plan and seek clinical advice if readings are persistently high.
• If you take anticoagulants or antiplatelet medicines, do not stop them yourself. Your clinician should have considered bleeding risk and your medication before the procedure.

A temporary “steroid flare” can cause increased pain or discomfort for a day or two. A wrapped cold pack for 10–15 minutes at a time may help; do not put ice directly on the skin. Use only pain relief that is safe for you and that your clinician has advised.

7. Possible side effects and risks

Most injections are completed without a serious complication, but no injection is risk-free. Discuss your individual risks before proceeding, particularly if you have diabetes, immune suppression, an infection, a bleeding disorder, significant allergies or previous problems after steroid treatment.

• Temporary pain or swelling: soreness or a flare can occur in the first 24–48 hours.
• Bruising or bleeding: minor bruising can occur, with greater concern in people taking blood-thinning medicines.
• Infection: this is uncommon but potentially serious. The joint must be assessed if infection is suspected before injection, and sterile technique is essential.
• Skin or tissue changes: thinning of the skin or soft tissue, a pale patch or a small indentation can occur, especially if steroid reaches tissues near the skin.
• Temporary flushing or other systemic effects: some people experience facial flushing, sleep disturbance, mood changes or a temporary rise in blood pressure or blood glucose. Although injected locally, some steroid can enter the bloodstream.
• Allergy or local anaesthetic reaction: serious reactions are rare but possible.
• Joint and tendon considerations: repeated injections may be associated with harm to cartilage or other tissues, depending on the joint, condition, dose and frequency. Steroid should not be injected into the substance of a tendon. Your clinician will consider these risks when choosing the site and whether an injection is appropriate.

An injection may be unsuitable if there is a suspected or confirmed infection in or around the joint, certain allergies to the preparation, or other clinical contraindications. Tell your clinician if you are pregnant or breastfeeding, have recently had an infection or vaccination, have poorly controlled diabetes, take immune-suppressing medication, or have had a previous unusual reaction to steroid or local anaesthetic.

8. When should I seek urgent medical advice?

Seek urgent medical assessment if you develop any of the following after an injection:

• Severe or rapidly worsening pain, increasing heat or redness, or marked swelling at the joint.
• Fever, chills, or feeling generally unwell, especially with a painful swollen joint.
• New inability to bear weight or move the joint, or a major deterioration rather than gradual improvement.
• Breathing difficulty, swelling of the face or throat, collapse, or another possible severe allergic reaction—call emergency services.

A post-injection infection can initially resemble a flare, so do not wait if pain is severe, worsening, or accompanied by fever or feeling unwell. Contact the clinic for advice if symptoms concern you, even if they do not match the examples above.

9. Might I need a second injection after 6–8 weeks?

Sometimes a further injection is considered when the first injection has produced a meaningful but incomplete or temporary benefit, and symptoms remain troublesome. In selected cases, review at around six to eight weeks may help determine whether the treatment plan needs to change. If a repeat injection is being considered, an interval of at least eight weeks is often a more cautious preference than repeating early—but the timing must be individualised and is not a promise that a second injection will be given.

A repeat injection is not automatic simply because pain remains. Before repeating, your clinician should review how much improvement occurred, how long it lasted, the diagnosis, the joint and injection site, the dose already used, other treatment options and the cumulative risks. If the first injection gave no meaningful benefit, repeating the same procedure may be less useful than reassessing the diagnosis or considering another treatment.

There is no single safe repeat schedule that applies to every joint and every patient. Repeated steroid injections may have local tissue effects, and frequent injections into the same joint are generally avoided. The decision should follow clinical review and relevant product guidance. Tell your clinician about injections you have received elsewhere and the approximate dates.

10. Questions to discuss with your clinician

• What structure is thought to be causing my pain, and what is the intended injection site?
• What improvement is realistic for my condition, and how will we measure it?
• What activity should I avoid, and when can I resume physiotherapy, work or sport?
• What are my personal risks, including any effects on diabetes, medicines or other conditions?
• If the injection does not help, when should I return and what alternatives may be appropriate?

Please ask questions before the procedure. You can decline or postpone an injection while you consider the options. Your treatment plan should be based on your symptoms, examination, goals and preferences.

Key points to remember

• Lignocaine may give quick but short-lived numbness; the steroid usually takes several days to work.
• Benefit varies and is not guaranteed; the injection reduces inflammation and symptoms but does not repair structural damage.
• Rest from strenuous activity for 24–48 hours, then build activity gradually.
• A repeat injection after about eight weeks may be considered in selected cases after review, but is not routine or automatic.
• Severe worsening pain, heat, swelling, fever or feeling unwell requires urgent assessment.

Further information

This sheet is a general patient information resource and cannot cover every circumstance. Your clinician’s advice for your specific condition takes precedence. The product information for Depo-Medrone describes intra-articular use and stresses accurate placement, sterile technique, appropriate dose selection and caution with repeat injections.

References for clinical background (accessed October 2026):

1. Electronic Medicines Compendium (emc), Depo-Medrone 40 mg/ml Suspension for Injection, Summary of Product Characteristics: https://www.medicines.org.uk/emc/product/8957/smpc
2. Electronic Medicines Compendium (emc), Depo-Medrone with Lidocaine, Summary of Product Characteristics: https://www.medicines.org.uk/emc/product/1081/smpc
3. ie, Irish product information for Depo-Medrone: https://www.medicines.ie/medicines/depo-medrone-40-mg-ml-1ml-vial-31806/patient-info