Cortisone Injection for Knee Arthritis

A corticosteroid or cortisone injection may reduce knee arthritis inflammation and pain for a limited period in selected patients. It is not a cure, does not regrow cartilage and should not be repeated automatically whenever symptoms return. The treatment should have a defined purpose such as supporting rehabilitation or controlling a painful inflammatory flare.

Quick Answer

• Corticosteroid injections are mainly used for short-term symptom relief.

• NICE advises explaining that relief is usually short term, approximately 2 to 10 weeks.

• Benefit varies and may be less predictable in advanced arthritis.

• Diabetes, infection, blood-thinning medicines and planned surgery must be reviewed.

• A poorly effective injection should not be repeated automatically.

What Is Injected?

An anti-inflammatory corticosteroid is placed inside the knee joint. It may reduce synovial inflammation, pain, swelling and stiffness. It does not replace lost cartilage or correct deformity, instability or severe joint-space loss.

Who May Be Considered?

• A painful osteoarthritis flare with inflammation or an effusion.

• Short-term relief to support physiotherapy, walking or an important functional goal.

• A patient who cannot use some oral anti-inflammatory medicines.

• A temporary measure when surgery is unsuitable or must be deferred.

• A patient with a confirmed intra-articular pain source and realistic expectations.

Who May Need a Different Plan?

• Suspected joint or skin infection.

• An uncertain diagnosis or pain mainly from the hip, spine or nerves.

• A previous correctly placed injection with no meaningful benefit.

• Severe deformity, major instability or constant disabling advanced-arthritis pain.

• Planned knee replacement without discussion of injection timing with the surgeon.

Expected Timing and Duration

Relief may begin within several days, although some patients have temporary soreness first. No fixed duration should be promised. Some obtain meaningful short-term benefit, some notice only a brief change and some do not respond. The result should be measured by function as well as pain.

What Happens During the Procedure?

1. The diagnosis, medicines, allergies, diabetes and recent illness are reviewed.

2. The skin is checked for infection, rash or wounds.

3. The site is cleaned using sterile technique.

4. Joint fluid may be aspirated when clinically indicated.

5. The medication is introduced into the joint, with image guidance when useful.

6. The patient receives activity, glucose-monitoring and warning-sign instructions.

Is Image Guidance Always Needed?

Many knee injections can be performed using anatomical landmarks. Ultrasound may be useful when anatomy is difficult, a prior injection failed, a large effusion needs evaluation or precise placement is especially important. Accurate placement does not guarantee clinical benefit because arthritis severity and pain mechanism still matter.

Risks and Precautions

• Temporary post-injection pain or flare.

• A temporary rise in blood glucose, particularly in diabetes.

• Bruising or bleeding, especially with anticoagulant treatment.

• Skin thinning or pigment change near the site.

• Rare joint infection requiring urgent treatment.

• Concern about cumulative cartilage effects with repeated exposure.

• Potential implications for future knee-replacement timing.

Diabetes

Blood glucose may rise temporarily after a steroid injection. Patients with diabetes should discuss monitoring and action thresholds with the clinician managing their diabetes, particularly when control is already poor or both knees are being considered.

Blood Thinners

Disclose aspirin, clopidogrel, warfarin, apixaban, rivaroxaban and other anticoagulants. Do not stop prescribed blood-thinning medicine independently. The decision depends on the specific drug, indication, bleeding risk and procedural plan.

How Often Can It Be Repeated?

There is no automatic safe schedule that applies to every patient. Prior benefit, duration, diabetes, arthritis stage, cumulative exposure, other options and planned surgery all matter. Progressively shorter relief or little functional improvement should prompt reassessment rather than increasingly frequent injections.

Using the Relief Window

Temporary symptom reduction can be used to restart strengthening, improve walking tolerance or address sleep and daily activity. Simply returning to excessive loading may provoke another flare. A rehabilitation plan should continue during the relief window.

Read Physiotherapy for Knee Arthritis.

Cortisone Compared With Other Injections

Cortisone is generally chosen for relatively rapid short-term anti-inflammatory relief. Hyaluronic acid, PRP and GFC have different rationales, evidence, cost and limitations. No option should be marketed as guaranteed cartilage regeneration.

Compare Hyaluronic Acid Injection, PRP Injection and GFC Therapy vs PRP.

When Cortisone Is Unlikely to Be Enough

It is less likely to solve the main problem when severe deformity, major loss of joint space, constant disabling pain, substantial instability or repeated failure of suitable non-surgical treatment is present.

Read When Knee Injections Stop Working.

Aftercare and Response Tracking

Follow the clinician’s instructions about strenuous activity, glucose monitoring and medication. Record pain, swelling, walking distance, sleep and the specific activity chosen as the treatment goal. Brief pain reduction without meaningful functional improvement may not justify repetition.

Warning Signs After Injection

A hot, red, rapidly swollen knee, fever, severe worsening pain or inability to bear weight requires urgent assessment. These symptoms should not be managed at home as a routine injection flare.

Questions Patients Commonly Ask

Can cortisone cure knee arthritis?

No. It may reduce inflammation and pain temporarily but does not reverse cartilage loss.

Will it increase blood sugar?

It can cause a temporary rise, particularly in diabetes. Monitoring may be required.

Can I walk after the injection?

Light activity is commonly possible, but unusually strenuous loading may be limited briefly according to the treating clinician’s instructions.

What if it does not work?

Review the diagnosis, placement, arthritis stage and alternative pain sources rather than automatically repeating it.

How many injections are safe?

There is no universal number. Benefit, interval, individual risk and the wider treatment plan determine whether another injection is reasonable.

Clinical References

NICE NG226: Osteoarthritis in over 16s—diagnosis and management

AAOS Clinical Practice Guideline: Management of Osteoarthritis of the Knee (Non-Arthroplasty)

American College of Rheumatology Osteoarthritis Guideline

About Dr. Mayur Rabhadiya

Dr. Mayur Rabhadiya is an Orthopedic and Joint Replacement Surgeon in Mumbai. Qualifications: MBBS, D’Ortho, DNB (Orthopedics), MNAMS (Orthopedics), FIJR (Robotic & Navigation). Read his professional profile.

Book a Consultation

Consultations are available in Ghatkopar East and Ghatkopar West, Mumbai. Call or WhatsApp +91 84249 03913 or +91 96113 30063, or use the appointment page.

Medical Author and Reviewer

Written and medically reviewed by Dr. Mayur Rabhadiya, MBBS, D’Ortho, DNB (Orthopedics), MNAMS (Orthopedics), FIJR (Robotic & Navigation). Last medically reviewed: 17 July 2026.

Medical Disclaimer

This guide provides general education and does not replace individual examination, injection consent or treatment advice.