What are the treatment options for arthritis in the knees?

Treatment of Knee Arthritis

Start with exercise therapy and weight loss as first-line treatment, add oral NSAIDs or acetaminophen for pain control, and reserve total knee replacement for patients with severe disability who fail conservative management. 1, 2

First-Line Non-Pharmacological Treatments

Exercise is the cornerstone of treatment and must be implemented initially:

• Quadriceps strengthening exercises significantly reduce pain (effect size 1.05) and improve function, with benefits lasting 6-18 months. 3 These exercises can be performed without regular professional supervision. 3

• Low-impact aerobic exercise provides substantial pain relief (effect size 0.52) and reduces disability (effect size 0.46). 1 Aim for 30-60 minutes of moderate-intensity aerobic activity most days of the week. 1

• Neuromuscular training combined with exercise improves function and walking speed. 2

• Manual therapy combined with exercise programs can be used to improve pain and function. 2

Weight loss is strongly recommended for overweight patients:

• Patients with BMI ≥25 kg/m² should achieve at least 5% body weight reduction to significantly improve function. 1 A large cohort study demonstrated that weight loss reduces the risk of developing symptomatic knee osteoarthritis in women. 3

• Combining dietary modification with exercise provides optimal results. 1

Patient education programs are essential:

• Self-management educational programs teaching coping skills and activity modifications reduce pain, though they have limited impact on function. 3, 1 Effective techniques include individualized education packages, regular telephone calls, group education, and spouse-assisted coping skills training. 1

Assistive devices may provide symptomatic relief:

• Walking sticks, insoles, and knee bracing can help, though evidence is relatively weak. 3, 1

• Do NOT prescribe lateral wedge insoles—they are not recommended. 1, 2

Pharmacological Treatment

For mild to moderate pain:

• Try acetaminophen first as the initial oral analgesic. 1 It improves pain and function in knee osteoarthritis. 2

For patients unresponsive to acetaminophen:

• NSAIDs are strongly recommended to improve pain and function when not contraindicated. 2 Use either non-selective NSAIDs with gastroprotective agents or selective COX-2 inhibitors for patients with increased gastrointestinal risk. 1

• Topical NSAIDs should be used to improve function and quality of life when not contraindicated. 2 They have clinical efficacy and are safe. 1

• Topical capsaicin cream may offer some benefit. 1

Important medication warnings:

• Do NOT routinely use tramadol or other opioids—they are not effective for improving pain or function and cause notable increases in adverse events. 2 Tramadol has a poor risk-benefit trade-off. 4

• Naproxen has been shown comparable to aspirin and indomethacin but with fewer gastrointestinal and nervous system side effects. 5

Injectable Treatments

Corticosteroid injections:

• Intra-articular corticosteroid injections are indicated for flares of knee pain, especially when accompanied by effusion. 1 They are effective either as monotherapy or adjunct to systemic therapy. 6

Hyaluronic acid injections:

• Do NOT use hyaluronic acid injections routinely—they are not recommended by the American Academy of Orthopaedic Surgeons. 2 Evidence for their effectiveness is mixed. 1

Platelet-rich plasma:

• PRP may reduce pain and improve function, but evidence is limited. 2 When compared to other injectables, PRP has shown longer-term symptomatic relief than hyaluronic acid and corticosteroid injections. 7

Treatments to AVOID

Do NOT perform these interventions:

• Arthroscopic debridement or lavage should NOT be done routinely for knee osteoarthritis. 2 Multiple high-quality studies have shown no benefit. 4, 8

• Free-floating interpositional devices should NOT be used due to revision rates of 32-62%. 2

Surgical Options

Total knee arthroplasty (TKA):

• Joint replacement should be considered for patients with radiographic evidence of knee osteoarthritis who have refractory pain and disability despite conservative management. 1 All studies report improvements in pain and function compared to baseline. 3

• TKA with 12 weeks of non-surgical treatment improves pain and functionality more than 12 weeks of non-surgical treatment alone at 12 and 24 months follow-up. 7

• Patients with severe symptomatic osteoarthritis require aggressive approaches and may benefit from orthopedic consultation for osteotomy or total joint arthroplasty. 6

Alternative surgical options:

• High tibial osteotomy may be considered for appropriately selected patients with unicompartmental knee osteoarthritis. 2

Additional Adjunctive Therapies

These modalities may provide supplemental benefit:

• Massage as an adjuvant to usual care can improve pain and function. 2
• Transcutaneous electrical nerve stimulation (TENS) may improve pain. 2
• FDA-approved laser therapy can improve pain and function. 2
• Extracorporeal shockwave therapy may improve pain and function. 2
• Denervation therapy can reduce pain and improve function. 2

Treatment Algorithm

Step 1: Initiate exercise (quadriceps strengthening + low-impact aerobic) and weight loss if BMI ≥25. 1

Step 2: Add acetaminophen for pain control. 1, 2

Step 3: If inadequate response, switch to or add oral NSAIDs (with gastroprotection if needed) or topical NSAIDs. 1, 2

Step 4: Consider intra-articular corticosteroid injections for flares with effusion. 1

Step 5: If severe disability persists despite conservative management with radiographic evidence of disease, refer for total knee arthroplasty. 1