Osteoarthritis is usually a slowly progressive degenerative disease in which the joint cartilage gradually wears away. Your joint cartilage, also called articular cartilage, is a smooth glistening surface that allows your joint to move smoothly with low friction.
Osteoarthritis most often affects middle-aged and older people. However, if can also affect young people if the joint cartilage has been damaged or weaked, such as in an injury.
What Topics are Covered?
What is Knee Osteoarthritis?
Knee osteoarthritis (OA) is a condition where the joint’s smooth cartilage becomes thinner and the surrounding tissues become irritated and inflamed. This leads to activity-related pain, stiffness after rest, swelling, and a feeling of instability on stairs or uneven ground. Symptoms can flare and settle—many people do well with a structured plan.
Common Symptoms
- Pain with activity or after prolonged sitting
- Morning or post-rest stiffness (usually <30–60 minutes)
- Swelling, creaking or grinding (crepitus)
- Reduced confidence with stairs, slopes or uneven ground
- Sleep disturbance during flares
Diagnosis: Getting It Right
Diagnosis is guided by your story and a focused examination. When imaging is needed, we usually start with weight-bearing knee X-rays. An MRI is not routinely required unless a different problem is suspected (e.g., a large locking meniscal tear, stress fracture) or for specific surgical planning.
Important: Pain severity doesn’t always match what scans show. We base decisions on your symptoms, goals and function—not images alone.
All Evidence-Based Treatment Options
International guidelines support a stepwise approach: start with education, activity pacing and physiotherapy; add medicines and supports as needed; consider injections or radiofrequency for persistent pain; and discuss surgery when symptoms remain life-limiting despite best non-operative care.
Foundations for Everyone
Education & Activity Pacing
Understanding OA and pacing activity reduces flares and improves confidence. Regular movement is safe and beneficial for the joint.
Targeted Exercise (Physiotherapy-Led)
- Strength: quadriceps, hips and calf
- Aerobic: brisk walking, cycling, swimming
- Neuromuscular & balance: control, stability and gait work
- Frequency: 2–3 structured sessions/week + daily movement
We can coordinate a program with your preferred physiotherapist or our clinic’s team. Learn more about physiotherapy.
Weight Management
If weight is above the healthy range, losing 5–10% of body weight can significantly reduce knee pain; benefits often increase beyond 10%. We pair nutrition advice with exercise for sustainable change.
Simple Supports
- Topical anti-inflammatory gel for local pain relief
- Heat/ice during flares
- Walking aid (cane in the opposite hand) for confidence
- Bracing: unloader braces for one-sided (unicompartmental) OA; patellofemoral braces for kneecap-pattern pain
- Footwear: supportive shoes; lateral wedge insoles aren’t routinely helpful
Medicines (Use the Smallest Effective Dose)
First-Line
- Topical NSAIDs (e.g., diclofenac gel): strong evidence for knee OA; fewer systemic side-effects than tablets.
Short Courses
- Oral NSAIDs: useful for flares when gels aren’t enough. We review stomach, kidney and heart risks and may add a PPI if appropriate.
Selective Add-Ons
- Duloxetine: can help where pain has a central amplification component or co-exists with low mood/anxiety.
- Paracetamol: limited benefit on its own; may help layered with other measures.
- Opioids: generally avoided for chronic OA pain due to small benefit and higher risk; if used, they’re short-term with a clear stop plan.
Injections (Short-Term Options)
Corticosteroid
Can reduce inflammation and pain for weeks, especially during a hot, swollen flare. We avoid frequent repetition as it does not improve long-term outcomes.
Hyaluronic Acid
May offer small benefit for some people but on average shows limited improvement; not routinely recommended in many modern guidelines.
Platelet-Rich Plasma (PRP)
Emerging evidence suggests PRP can outperform hyaluronic acid at 3–12 months. Protocols vary; access and cost are discussed in advance.
Stem-cell injections: not TGA-approved for knee OA; we recommend participation only within properly approved clinical trials.
Radiofrequency Ablation (RFA) of the Genicular Nerves
Minimally invasive, day-case procedure targeting small sensory nerves that carry pain signals from the knee. Randomised trials show improved pain and function for suitable patients, often lasting several months; the procedure can be repeated.
- Best for: persistent pain after thorough non-operative care, where surgery is not desired or needs to be delayed.
- What it doesn’t do: RFA does not change joint structure.
Surgery: When and Which Operation?
We consider surgery when symptoms remain severe—pain, sleep disturbance, major activity limits—despite best non-operative care and when examination and imaging match your symptoms.
Realignment Osteotomy
For younger, active patients with one-sided OA and malalignment (e.g., bow-leg). Can delay replacement for years.
Partial Knee Replacement
For isolated compartment OA with intact ligaments. Smaller incision and quicker recovery for selected patients.
Total Knee Replacement
For multi-compartment disease. Outcomes in Australia are tracked through the national joint registry, supporting safety and long-term performance.
Quick Comparison: Treatments & Evidence
| Treatment | What it does | Evidence summary | Who it suits |
|---|---|---|---|
| Exercise & weight loss | Reduces pain, boosts strength and function | Core recommendation across major guidelines | Everyone with knee OA |
| Topical NSAIDs | Local anti-inflammatory pain relief | First-line for knee OA | Mild–moderate pain; when tablets are risky |
| Oral NSAIDs | Systemic anti-inflammatory | Effective vs placebo; review risks | Flares not controlled by topicals |
| Duloxetine | Central pain modulation | Conditional recommendation | Persistent pain with mood/sleep overlay |
| Corticosteroid injection | Short-term relief in inflamed flares | Weeks of benefit; avoid frequent repeats | Hot, swollen knees needing quick relief |
| Hyaluronic acid | Lubricant/viscosupplement | Small average benefit; not routine | Selected cases after discussion |
| PRP | Biologic modulation | Often better than HA at 3–12 months | Non-surgical option after basics |
| Genicular RFA | Desensitises pain nerves | Improves pain/function up to 6–12 months | Persistent pain not ready for TKR |
| Arthroscopy | “Clean-out” surgery | Not effective for degenerative OA | Only for true mechanical locking |
| Osteotomy / Partial / Total Knee Replacement | Realign or resurface joint | Reliable long-term relief when indicated | Advanced OA after best non-operative care |
A Practical, Step-by-Step Plan
- Learn & Load Smart — Understand OA, set goals, and keep moving daily.
- Physiotherapy Program — Strength, aerobic, balance and gait training.
- Add Simple Supports — Topical gel, brace if appropriate, heat/ice, walking aid.
- Short Medication Trials — Oral NSAIDs for flares; consider duloxetine when indicated.
- Consider Procedures — Steroid (for inflamed flares), PRP, or radiofrequency ablation.
- Reassess — If pain still limits life, discuss partial/total knee replacement or osteotomy.
Frequently Asked Questions
Is exercise safe for my knee?
Yes. Regular, progressive exercise reduces pain and improves function. We scale your program to your current ability and build gradually.
Do I need an MRI?
Usually no. Most people are diagnosed with history, examination and, if needed, weight-bearing X-rays. We reserve MRI for specific situations.
Are injections mandatory before surgery?
No. Injections are optional for symptom control. If pain remains severe despite best non-operative care, discussing surgery is appropriate.
Can I delay or avoid knee replacement?
Often, yes—through exercise, weight management, supports, medicines, and options like PRP or RFA. When symptoms remain life-limiting, surgery is the reliable next step.
Medical information disclaimer
This page offers general information and does not replace an in-person medical assessment. Your situation may differ; please seek personalised advice.
Ready to Take the Next Step?
If knee pain is limiting your work, family time, or sleep, we can help—starting with a thorough assessment and a clear, personalised plan.
