Why Injections? The Gap Between Pain Tablets and Surgery
For patients with moderate to advanced knee or hip arthritis, there exists an uncomfortable middle ground: oral pain medications are no longer providing sufficient relief, but the condition has not yet reached the severity that would justify joint replacement surgery. It is in this clinical space — often lasting months or years — that intra-articular injections become highly relevant.
Injections deliver medication directly into the joint space, bypassing the digestive system entirely. This allows for a much higher local concentration of the therapeutic agent at the site of pain and inflammation, with significantly reduced systemic side effects compared to long-term oral NSAIDs.
The right injection at the right time can meaningfully restore function and quality of life — but the wrong one can accelerate the very damage you are trying to slow.
— Dr. Sarish Sharma, MS OrthopaedicsThe two most frequently offered options are Hyaluronic Acid (HA) injections — also called viscosupplementation or joint lubrication therapy — and Corticosteroid (Cortisone) injections. These are not interchangeable. They target entirely different mechanisms of joint pain, work over different timescales, carry different risk profiles, and are appropriate for different patient profiles. Understanding the distinction is essential before consenting to either.
How Each Injection Actually Works
- Hyaluronic acid is a naturally occurring substance found in healthy joint fluid (synovial fluid)
- In arthritic joints, HA concentration drops — causing friction, reduced cushioning, and pain
- Injected HA temporarily restores the viscoelastic properties of joint fluid
- Acts as both lubricant (reduces bone-on-bone friction) and shock absorber
- May also stimulate the joint's own HA production over time
- Has mild anti-inflammatory properties through cytokine modulation
- Cortisone is a synthetic version of cortisol — the body's own stress hormone
- Works by powerfully suppressing the immune and inflammatory response inside the joint
- Reduces swelling, heat, and chemical pain signals within days
- Does not restore joint fluid or cartilage — purely targets inflammation
- Highly effective when inflammation is the dominant driver of pain
- Effect is temporary — does not slow disease progression
The Key Conceptual Difference
Think of it this way: Hyaluronic acid is a structural intervention — it tries to restore the mechanical environment of the joint. Cortisone is a chemical intervention — it suppresses the inflammatory signals that cause pain. One lubricates; the other quiets. A patient with significant cartilage loss and mechanical friction benefits most from HA. A patient with a hot, swollen joint driven by acute synovitis benefits most from cortisone.
Side-by-Side Comparison
| Factor | 💧 Hyaluronic Acid | 🔥 Cortisone |
|---|---|---|
| Mechanism | Lubricates & cushions the joint, restores synovial fluid viscosity | Suppresses joint inflammation & immune response |
| Onset of Relief | Gradual — 2 to 6 weeks Slower | Fast — often within 2 to 5 days Faster |
| Duration of Effect | 6 months to 1 year or more Longer | 4 to 12 weeks Shorter |
| Number of Sessions | 1–3 injections (sometimes a course of 3–5 weekly) | Single injection; can repeat with restrictions |
| Best For | Mild to moderate osteoarthritis; long-term management | Acute flare-ups; significant joint swelling; pre-procedure relief |
| Effect on Cartilage | Protective — may slow cartilage degradation Better | Potentially damaging with repeated use Caution |
| Effect on Blood Sugar | Minimal / none Safer for diabetics | Can spike blood sugar for 1–2 weeks Caution in diabetes |
| Frequency Limit | Can be repeated annually with fewer restrictions | Maximum 3–4 times per year in any one joint |
| Cost | Higher per session | Lower per session |
| Evidence Strength | Strong for moderate OA, variable for severe OA | Strong for acute inflammation; limited long-term data |
| Pre-surgery use | Not recommended within 3 months before surgery | Not recommended within 3 months before surgery |
Who Is Each Injection Right For?
The decision is not simply about which is 'better' — it is about which is more appropriate for your specific situation. These are the clinical profiles where each injection tends to perform best.
- You have mild to moderate osteoarthritis (Grade 1–3 on X-ray)
- Your pain is chronic and ongoing, not an acute flare
- You have tried cortisone before but effects wore off quickly
- You have Type 2 diabetes or need to avoid blood sugar spikes
- You want longer-lasting relief with fewer repeat injections
- You are trying to delay joint replacement surgery
- Your joint fluid is reduced but not severely inflamed
- You are under 65 with an active lifestyle to protect
- Your joint is acutely swollen, hot, and inflamed
- You need rapid relief — an upcoming event, travel, or procedure
- You have severe arthritis with significant synovitis
- You are preparing for physiotherapy and need pain reduction first
- You've had good results from cortisone previously and relapsed
- Budget is a significant constraint in your treatment decision
- You are awaiting surgery and need temporary symptom control
- Inflammatory arthritis (rheumatoid) is contributing to your pain
Combination Approach: In some patients, a cortisone injection is given first to rapidly reduce acute inflammation and swelling, followed several weeks later by a hyaluronic acid injection to provide longer-term lubrication and structural support. This staged protocol is used selectively and only when clinically appropriate.
Risks & Side Effects: What You Must Know
Generally considered very safe. Serious complications are rare.
- → Injection site reaction — temporary swelling, warmth, or mild pain for 24–72 hours (10–20% of patients)
- → Pseudo-septic reaction — rare acute inflammatory flare (1–2%) requiring drainage; not a true infection
- → Infection — very rare (<0.01%) if performed with strict sterile technique
- → Allergy — rare; patients allergic to avian products should confirm non-animal-derived HA formulations are used
- → No effect — some patients (especially with severe Grade 4 OA) may not respond; this is a treatment limitation, not a complication
More potent anti-inflammatory effect comes with a more significant risk profile, especially with repeated use.
- → Blood sugar elevation — can raise glucose levels significantly for 5–14 days; requires close monitoring in diabetics
- → Cartilage degradation — repeated cortisone injections (more than 3–4 per year) are associated with accelerated cartilage loss; this is a major clinical concern
- → Tendon weakening — steroid near tendons increases rupture risk; requires post-injection activity restriction
- → Skin & fat atrophy — depigmentation and thinning of skin at injection site (more common with repeated superficial injections)
- → Infection risk — suppresses local immune response; low but real risk of joint sepsis
- → Steroid flare — paradoxical worsening of joint pain 12–24 hours post-injection in ~10% of patients; usually self-limiting within 48 hours
Critical Warning for Diabetic Patients: Cortisone injections can cause dangerous hyperglycaemia (high blood sugar) lasting up to two weeks. If you have Type 1 or Type 2 diabetes, discuss this explicitly with your doctor before any steroid injection and plan for increased blood sugar monitoring post-procedure. Hyaluronic acid is generally the preferred alternative in this population.
Common Myths About Joint Injections — Debunked
What Happens During & After the Injection?
Many patients feel anxious about joint injections, often imagining them as far more uncomfortable or complex than they are. Here is a clear picture of the process.
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01Assessment & Imaging Review
Your orthopaedic specialist reviews your X-rays or MRI to confirm the grade of arthritis and select the appropriate injection. The injection site and patient position are determined based on the joint being treated.
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02Skin Preparation & Local Anaesthetic
The skin over the injection site is cleaned thoroughly with antiseptic. A small amount of local anaesthetic may be applied to numb the area. For HA injections, this is often mixed directly with the HA formulation.
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03The Injection (30–60 seconds)
The needle is carefully guided into the joint space. If there is significant swelling, joint fluid may first be aspirated (removed) to create space and relieve pressure — this often provides immediate comfort. The medication is then injected. Most patients describe mild pressure rather than sharp pain.
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04Immediate Post-Injection (0–24 hours)
Rest the treated joint for the remainder of the day. Avoid strenuous activity, heavy lifting, and prolonged walking. A mild aching or fullness in the joint is normal. Ice packs (20 minutes, 3–4 times) help reduce soreness. Do not apply heat.
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05Return to Normal Activity (Days 2–7)
Light daily activities can typically resume after 48 hours. For cortisone, blood sugar monitoring should continue for 1–2 weeks in diabetic patients. For HA, gentle movement during the integration period (weeks 2–6) is encouraged to spread the gel through the joint space.
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06Follow-Up Assessment (4–8 weeks)
Your response to the injection is reviewed. This determines whether a repeat injection is needed, whether a different treatment approach should be adopted, and how physiotherapy should be integrated going forward.
When Neither Injection Is the Right Answer
Both HA and cortisone are powerful tools — but they are not always the appropriate intervention. Knowing when to move beyond injections is as important as knowing which one to choose.
- → End-stage arthritis (Grade 4): When cartilage is completely absent and bone rubs directly on bone, HA has limited benefit and the patient should be assessed for joint replacement
- → Active joint infection (septic arthritis): Injecting into an infected joint can be catastrophic — sterilisation and systemic antibiotics are the priority
- → Skin infection at the injection site: Proceeding through infected skin carries a serious risk of introducing bacteria into the joint
- → Planned surgery within 3 months: Both injections increase post-operative infection risk and should be avoided in this window
- → Uncontrolled blood clotting disorders or anticoagulant therapy: Requires careful haematological assessment before proceeding
When injections are not appropriate or have been exhausted, other interventional options — including PRP (Platelet Rich Plasma) therapy, nerve blocks, prolotherapy, or joint replacement surgery — may be considered depending on the patient's clinical profile, age, and functional goals.
The decision between hyaluronic acid, cortisone, PRP, or surgical intervention should always be made through a thorough consultation — reviewing imaging, blood markers, functional assessment, and your personal health priorities together. No injection should be offered as a reflex without proper evaluation.
Not Sure Which Injection Is Right for You?
Book a detailed orthopaedic consultation with Dr. Sarish Sharma. Your X-rays, health profile, and treatment goals will guide the right decision — together.
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