Treatment of knee osteoarthritis

1. Core treatment for nearly everyone

• Understand that pain can fluctuate and that regular activity is safe when progressed gradually.
• Avoid repeated high-impact loading during painful flares, but do not rest completely.
• Use pacing: split prolonged standing, stair climbing, squatting, or walking into shorter periods.

• This is the main treatment.
• Strengthening of quadriceps, hip abductors, and core muscles.
• Range-of-motion work and low-impact aerobic exercise: walking, cycling, swimming, water exercise, or tai chi.
• Supervised physiotherapy can help with exercise selection, gait, balance, and adherence. AAOS recommends supervised, home-based, and aquatic exercise programs. Miller's Review of Orthopaedics, 9th ed., Table 5.7.
• A recent systematic review also supports physical therapies for pain and function in knee OA (PMID: 41426589).

• Sustained loss of body weight reduces force across the knee and improves symptoms. Even a modest, maintained reduction can help.
• Combine dietary support with strengthening and aerobic activity rather than relying on diet alone.

• A cane in the hand opposite the painful knee can reduce load.
• A tibiofemoral unloading brace may help selected people, particularly with predominantly medial-compartment OA and varus alignment.
• Supportive, cushioned footwear may help comfort. Lateral-wedge insoles are not routinely recommended. Miller's Review of Orthopaedics, 9th ed., Table 5.7.

2. Medicines for pain

• Diclofenac gel or another topical NSAID is often the preferred initial drug treatment, particularly in older adults or those with gastrointestinal risk.
• Apply as directed to intact skin and avoid combining indiscriminately with oral NSAIDs.

• Examples: ibuprofen, naproxen, celecoxib, etoricoxib.
• They can be effective but require caution or avoidance with:
  • Previous stomach ulcer or gastrointestinal bleeding
  • Chronic kidney disease
  • Heart failure, uncontrolled hypertension, or significant cardiovascular disease
  • Anticoagulants
  • Pregnancy
• A clinician may prescribe a proton-pump inhibitor for stomach protection in people at gastrointestinal risk.

• May be tried for short-term, occasional pain, but its average benefit is usually modest. Avoid exceeding the labeled maximum and use particular caution with liver disease or substantial alcohol intake.

• Topical capsaicin may help some people but can cause burning skin irritation.
• Duloxetine can be considered for persistent chronic knee pain, especially where pain sensitization, sleep disturbance, anxiety, or depression coexist. It needs clinician supervision.
• Opioids, including tramadol, are generally poor long-term options because benefits are limited and risks include falls, dependence, constipation, and sedation. AAOS does not recommend routine use. Miller's Review of Orthopaedics, 9th ed., Table 5.7.

3. Injections

• May provide short-term pain relief, particularly during an inflammatory flare with swelling.
• Benefit is temporary, commonly weeks rather than a lasting solution.
• Repeated injections should be limited and individualized. Avoid injection if joint infection is suspected.

• Not routinely recommended by AAOS because average benefit is uncertain or small. Miller's Review of Orthopaedics, 9th ed., Table 5.7.

• These are not standard established treatments. The American College of Rheumatology guidance recommends against PRP and stem-cell injections for knee OA because of insufficient reliable benefit and variability of products, as summarized by the ACR treatment guidance.

4. Procedures and surgery

• Knee washout or debridement for OA alone is not recommended.
• Arthroscopic partial meniscectomy may occasionally be considered for a true symptomatic meniscal tear with mechanical symptoms, but not simply because an MRI shows degenerative meniscal changes. Miller's Review of Orthopaedics, 9th ed., Table 5.7.

• For a younger, active person with disease largely confined to one compartment plus significant varus or valgus malalignment, realignment osteotomy may be an option.

• Consider when pain, disability, disturbed sleep, and reduced quality of life remain severe despite a well-conducted non-surgical program, and imaging plus examination confirm advanced OA.
• A unicompartmental knee replacement may suit selected patients with disease limited to one knee compartment.
• Total knee arthroplasty is appropriate for end-stage symptomatic disease affecting more than one compartment. The AAOS surgical guideline resource covers operative options.

Practical stepped plan

1. Begin or restart a tailored strengthening and low-impact aerobic program.
2. If overweight, add a sustainable weight-loss plan.
3. Use topical NSAID if safe.
4. Add a cane, brace, or physiotherapy assessment when walking is limited.
5. If symptoms persist, discuss oral NSAID suitability, duloxetine, or a corticosteroid injection with a clinician.
6. Seek orthopedic assessment for persistent severe pain and functional limitation despite these measures.

Seek urgent assessment if

• A knee becomes suddenly hot, very swollen, red, and extremely painful
• Fever or feeling unwell accompanies the joint symptoms
• You cannot bear weight after injury
• The calf becomes swollen or painful, or you develop chest pain or breathlessness