Cortisone Injection for Knee Arthritis Explained by Dr. Mayur Rabhadiya

What Is a Cortisone Injection for Knee Arthritis?

A cortisone injection is an anti-inflammatory medicine placed directly inside the knee joint.

It is also called:

A corticosteroid injection
A steroid injection
An intra-articular corticosteroid injection
A knee cortisone shot

The purpose is to reduce inflammation and provide temporary relief from knee arthritis pain. It does not remove the arthritis or rebuild the damaged joint surface.

Dr. Mayur Rabhadiya considers a cortisone injection only after confirming the likely source of pain and reviewing the patient’s symptoms, examination, X-rays, medical conditions and previous treatment.

Patients comparing different injection options can first read about knee injections for arthritis.

How Does a Steroid Injection Work?

Corticosteroids are powerful anti-inflammatory medicines.

When injected into the knee joint, they may reduce inflammation within the joint lining and decrease:

Pain
Swelling
Stiffness
Discomfort during walking
Pain that prevents exercise

The injection treats inflammation and symptoms. It does not correct the structural cause of osteoarthritis.

A reduction in pain after an injection should not be interpreted as:

Cartilage regeneration
Restoration of lost joint space
Reversal of bone-on-bone arthritis
Correction of bow-leg or knock-knee deformity
Permanent cure of the condition

Symptoms can return as the effect of the medicine wears off.

When May a Cortisone Injection Be Considered?

A cortisone injection may be considered when:

Knee arthritis remains painful despite appropriate initial treatment
The knee has an inflammatory flare with swelling
Oral anti-inflammatory medicines are unsuitable
Medicines cause unacceptable side effects
Pain prevents participation in physiotherapy
Short-term symptom relief is required
Surgery is not currently appropriate
Surgery must be delayed for medical or personal reasons
A previous injection provided useful relief

It should usually support a wider treatment plan rather than become the only intervention.

Pain relief may allow a patient to participate more effectively in:

Strengthening exercises
Physiotherapy
Walking progression
Weight management
Daily activities

Patients should use the period of improvement to build strength and function rather than simply stop all treatment until the pain returns.

Who May Be Less Likely to Benefit?

A steroid injection may provide limited or short-lived benefit when there is:

Severe bone-on-bone arthritis
Major fixed deformity
Marked knee stiffness
Significant instability
Pain arising mainly from the hip or spine
Pain caused by a fracture or another bone condition
Incorrect diagnosis
Several previous injections with diminishing relief
Severe functional limitation requiring surgical assessment

An injection may still occasionally be considered in advanced arthritis when surgery is unsuitable or temporary relief is required. Expectations should remain realistic.

Confirming the Diagnosis Before Injection

Not every painful or swollen knee should receive a steroid injection.

Similar symptoms may result from:

Gout
Inflammatory arthritis
Infection
Meniscal disease
Ligament injury
Tendon problems
Fracture
Referred pain from the hip or spine

A hot, red and rapidly swollen knee may require joint-fluid aspiration and laboratory testing rather than an immediate corticosteroid injection.

Assessment may include:

Symptom history
Examination
Knee alignment
Range of movement
Swelling and tenderness
Ligament stability
Weight-bearing X-rays
Blood tests or joint-fluid analysis when indicated

MRI is not routinely required before a steroid injection when the diagnosis of knee osteoarthritis is already clinically clear.

How Is the Injection Performed?

The patient is positioned so that the knee joint can be accessed safely.

The clinician:

Identifies the injection site.
Cleans the skin using an antiseptic solution.
Uses sterile technique.
Inserts a needle into the knee joint.
Removes excess joint fluid when aspiration is required.
Injects the corticosteroid, sometimes with a local anaesthetic.
Applies a small dressing.

The procedure is usually completed within a few minutes.

The patient may feel pressure or temporary discomfort during the injection.

Is Ultrasound Guidance Necessary?

Many knee-joint injections can be performed accurately using anatomical landmarks.

Ultrasound guidance may be useful when:

The anatomy is difficult to identify
Obesity makes landmarks less clear
A previous injection may have missed the joint
Aspiration of a specific fluid collection is required
The clinician needs direct visual confirmation of needle placement

Ultrasound guidance may improve placement accuracy in selected situations, but it does not guarantee clinical benefit.

Correct diagnosis and appropriate patient selection remain more important than imaging guidance alone.

How Quickly Does Cortisone Begin to Work?

Some patients notice improvement within a few days. Others require longer, and some obtain little or no relief.

When a local anaesthetic is included, temporary improvement may occur immediately. This early numbing effect can wear off before the corticosteroid begins working.

The response should be judged over the following days rather than only during the first few hours.

Temporary worsening of pain during the first one or two days can occur. This is sometimes called a post-injection flare.

How Long Does Relief Last?

Cortisone injections usually provide short-term relief.

The benefit may last:

A few weeks
Approximately two to ten weeks in many patients
Up to around three months in some patients
A shorter or longer period in individual cases

Some patients do not improve.

Duration depends on:

Arthritis severity
Degree of inflammation
Accuracy of diagnosis
Previous injection response
Body weight
Activity
Muscle strength
Deformity
Rehabilitation after the injection

A single successful response does not predict that every future injection will work equally well.

What Should Be Done After the Injection?

After the injection, the patient may be advised to:

Avoid strenuous activity for a short period
Continue gentle knee movement
Avoid running, jumping or heavy exercise immediately
Monitor the injection site
Resume rehabilitation gradually
Follow the prescribed exercise plan
Contact the clinic if pain or swelling worsens substantially

The patient should not test the injection by immediately undertaking a long walk or demanding workout.

When pain improves, activity should be increased gradually.

Cortisone Injection and Diabetes

A steroid injection can temporarily increase blood glucose.

The rise may be more important in patients with:

Poorly controlled diabetes
Insulin treatment
Previous significant glucose elevation after steroid exposure
Multiple medical conditions
An active infection

Patients with diabetes should tell the clinician before the injection.

They may need to:

Monitor glucose more frequently
Follow their diabetes clinician’s instructions
Maintain adequate hydration
Seek advice if readings become unusually high
Avoid changing insulin or diabetes medicines without an agreed plan

The injection is not automatically prohibited in every patient with diabetes, but the expected benefit should justify the metabolic risk.

Blood Thinners and Steroid Injections

Patients taking blood-thinning medicines should disclose them before the procedure.

These may include:

Aspirin
Clopidogrel
Warfarin
Apixaban
Rivaroxaban
Dabigatran
Injectable anticoagulants

Do not stop these medicines independently.

The clinician will consider:

The specific medicine
Reason it was prescribed
Bleeding risk
Kidney function
Previous blood clots
Injection technique

For many patients, stopping anticoagulation unnecessarily may create a greater risk than performing the procedure with an appropriate plan.

Risks and Side Effects

Possible side effects include:

Temporary pain flare
Bruising
Bleeding
Skin irritation
Facial flushing
Temporary blood-glucose elevation
Skin thinning or colour change
Fat loss beneath the skin
Allergic reaction
Failure to improve
Joint infection

Repeated injections may be associated with concern about cartilage and other joint-tissue effects.

The risk from a single appropriately selected injection differs from the risk of repeated injections administered routinely without reassessment.

Infection After a Knee Injection

Joint infection after an injection is uncommon but potentially serious.

Seek prompt medical assessment for:

Rapidly increasing pain
Marked swelling
Spreading redness
Increasing warmth
Fever
Chills
Inability to bear weight
Progressive deterioration after the procedure

A brief period of mild discomfort is different from a knee that becomes progressively more painful, hot and swollen.

Do not wait several days with severe worsening symptoms.

How Often Can Cortisone Injections Be Given?

There is no universal number that is appropriate for every patient.

Many clinicians use a practical limit of approximately three to four injections in one joint during a year, but this is not a target that patients should routinely receive.

The decision should consider:

Duration of relief from the previous injection
Arthritis severity
Diabetes
Infection risk
Skin and tissue effects
Other treatment options
Future surgery plans
Overall functional decline

If each injection provides progressively shorter relief, repeating the same treatment may no longer be reasonable.

A patient who received several weeks of relief once does not automatically require another injection whenever pain returns.

Do Repeated Steroid Injections Damage Cartilage?

Evidence has raised concern that repeated intra-articular corticosteroid exposure may adversely affect cartilage or accelerate structural change in some circumstances.

The clinical significance varies with:

Dose
Frequency
Arthritis severity
Injection formulation
Length of follow-up

This does not mean that every steroid injection inevitably damages the knee.

It means the treatment should be used selectively for a clear short-term objective rather than repeatedly presented as harmless maintenance therapy.

Cortisone Injection Before Knee Replacement

The surgeon should be told about every injection given into the knee being considered for replacement.

Knee replacement is generally avoided for at least three months after a corticosteroid injection into that knee because injections given close to surgery may increase the risk of prosthetic-joint infection.

Patients should therefore not arrange an injection independently when:

Knee replacement is being planned
Preoperative tests have begun
A surgical date is being considered
Another surgeon has already recommended replacement

The timing should be coordinated with the treating knee replacement surgeon.

Can Cortisone Delay Knee Replacement?

A steroid injection may temporarily reduce pain and allow a patient to continue non-surgical treatment.

It may be useful when:

Symptoms remain manageable
Function is reasonably preserved
Surgery is not currently desired
Medical optimisation is required
A temporary delay is clinically appropriate

However, it cannot guarantee avoidance of surgery.

Repeated injections should not be used only to postpone reassessment while:

Walking distance declines
Night pain worsens
Deformity progresses
Independence is lost
Relief becomes increasingly brief

When Should Another Treatment Be Considered?

The treatment plan should be reviewed when:

The injection provides no benefit
Relief lasts only a few days
Each injection works for a shorter period
The knee remains substantially swollen
The diagnosis is uncertain
Diabetes control becomes difficult
The patient requires frequent injections
Functional limitation continues to progress
Knee replacement may now be appropriate

Options may include:

Reviewing exercise and physiotherapy
Reassessing medicines
Weight management where relevant
Considering another appropriate injection category
Reviewing the diagnosis
Discussing surgical treatment

Changing only the steroid brand may not solve the problem if advanced arthritis is the main reason for treatment failure.

Frequently Asked Questions About Cortisone Injections

Is cortisone the same as a steroid injection?

Yes. Cortisone injection, corticosteroid injection and steroid injection are commonly used to describe the same treatment category.

Does a cortisone injection cure knee arthritis?

No. It temporarily reduces inflammation and pain but does not cure structural osteoarthritis.

How quickly does it work?

Some patients improve within a few days. The response may take longer, and not every patient benefits.

How long does relief last?

Relief is usually temporary, commonly lasting several weeks and sometimes up to approximately three months.

Why did my knee hurt more after the injection?

A temporary post-injection flare can occur. Severe or progressively worsening pain requires assessment.

Can cortisone regrow cartilage?

No. Cortisone is not a cartilage-regeneration treatment.

Can it help bone-on-bone arthritis?

It may provide temporary relief in some patients, but benefit may be limited in advanced arthritis with deformity or severe stiffness.

Is the injection painful?

Temporary pressure or discomfort may occur. The experience varies between patients.

Is ultrasound guidance required?

Not for every knee injection. It may be useful when anatomy is difficult or previous landmark-guided placement has been unsuccessful.

Can people with diabetes receive cortisone?

Possibly, but glucose may rise temporarily. Diabetes control and monitoring should be discussed beforehand.

Can I receive an injection while taking blood thinners?

It may be possible with an individual plan. Do not stop blood thinners without medical instructions.

How many injections can I receive?

There is no universal number. Repetition depends on benefit, risks, medical conditions and future treatment plans.

Are three or four injections per year always safe?

No. This is sometimes used as a practical upper limit, not a recommendation that every patient should receive that many.

Can repeated injections damage the knee?

Repeated corticosteroid exposure may have adverse effects on cartilage and surrounding tissues. Injections should be used selectively.

When can I exercise after the injection?

Gentle movement is usually continued, followed by gradual return to exercise according to the clinician’s instructions.

Can I have knee replacement soon after an injection?

Replacement of the injected knee is generally delayed for at least three months to reduce infection risk.

When should I seek urgent help?

Seek prompt assessment for increasing pain, severe swelling, redness, fever, chills or inability to bear weight.

What should I do if the injection stops helping?

The diagnosis, arthritis severity and complete treatment plan should be reassessed rather than automatically repeating the injection.

About Dr. Mayur Rabhadiya

Dr. Mayur Rabhadiya is an Orthopedic & Joint Replacement Surgeon in Mumbai.

His qualifications include MBBS, D’Ortho, DNB Orthopedics, MNAMS Orthopedics and a Fellowship in Robotic & Computer-Navigated Joint Replacement.

His approach to knee injections is evidence-based and patient-specific. Cortisone injections are considered for a defined short-term purpose after confirming the diagnosis and reviewing medical risks, previous treatment and realistic alternatives.

His practice includes knee arthritis assessment, selected GFC therapy, total knee replacement, partial knee replacement, robotic knee replacement, bilateral knee replacement and revision knee replacement.

Last medically reviewed: June 2026.

Book a Knee Arthritis Injection Consultation in Mumbai

Patients considering a cortisone injection or seeking an opinion after previous injections have stopped helping can consult Dr. Mayur Rabhadiya at Ghatkopar East or Ghatkopar West, Mumbai.

Call +91 84249 03913 or +91 96113 30063.

Appointments can also be requested through the orthopedic doctor consultation page.

Medical References

This page is informed by current guidance from the National Institute for Health and Care Excellence and the American Academy of Orthopaedic Surgeons concerning intra-articular corticosteroid injections for knee osteoarthritis.

Medical Disclaimer

This information is intended for general patient education and does not replace clinical examination or personalised injection advice.

Suitability for a corticosteroid injection depends on the diagnosis, arthritis severity, diabetes control, medicines, infection risk, previous response and plans for surgery. Do not stop blood-thinning or diabetes medicines without instructions from the relevant treating clinician.