Knee osteoarthritis: key treatments and implications for physical therapy

Key points

1. 01Education, exercise, and weight loss (for overweight patients) are the recommended first-line treatments endorsed by all major guidelines
2. 02High-quality evidence confirms exercise improves pain, physical function, and quality of life, with benefits sustained 2-6 months after treatment ends
3. 03A weight reduction of 5-10% in adults with knee OA and BMI 33.6-36.4 kg/m2 significantly improves pain, disability, and quality of life
4. 04Adjunct therapies including thermal modalities, laser, ultrasound, electrical stimulation, and taping have very low or no supporting evidence and most guidelines recommend against them
5. 05Less than 40% of patients with knee OA receive guideline-recommended first-line non-pharmacological treatment

How it was conducted

Design

Narrative masterclass review synthesizing international guidelines and trial evidence

Scope

Non-pharmacological treatments, pharmacological treatments, surgery, and outcome measures for knee OA

Guidelines reviewed

NICE, OARSI, ACR, Ottawa Panel, EULAR

Target audience

Physical therapists and rehabilitation clinicians treating knee OA

Key data source

Data from 9825 patients with hip or knee OA from a 6-week education plus neuromuscular exercise program

What they found

• A 6-week combined education and neuromuscular exercise intervention in 9825 patients with hip or knee OA had beneficial effects on OA symptoms, physical function, medication intake, and sick leave time, with some benefits maintained at one year
• Exercise benefits for pain, physical function, and quality of life are sustained for at least 2-6 months after treatment ends
• A weight reduction of 5.1 kg decreases the risk of developing knee OA by more than 50% in women with BMI above 25.0 kg/m2
• A 5-10% weight reduction in adults with knee OA and mean BMI 33.6-36.4 kg/m2 significantly improved pain, self-reported disability, and quality of life
• Patients who are overweight should aim for at least 7.7% body weight loss to achieve a minimal clinically important improvement in physical function
• Opioids showed only small effects on pain and physical function, and patients using opioids had 3-4 times higher risks of serious adverse effects or drop-out compared to placebo
• One in five patients undergoing total knee replacement is not satisfied with the outcome
• Arthroscopic surgery has low efficacy for pain relief and physical function improvement, and increases chances of subsequent knee replacement surgery

Limitations

• This is a narrative review, not a systematic review or meta-analysis, so selection of evidence may reflect author judgment rather than exhaustive search
• Specific effect sizes and confidence intervals for most interventions are not reported, limiting precise clinical comparisons
• Recommendations for exercise parameters (duration, frequency, intensity) remain largely based on expert opinion rather than high-quality trials
• Adjunct therapy evidence base is heterogeneous and many included studies have methodological limitations

Why it matters

For patients

Patients with knee OA should know that exercise, education, and weight loss are more effective and safer than many popular treatments like ultrasound, laser, or opioids.

For clinicians

Physical therapists should prioritize education, individualized exercise, and weight management as core treatment, and should be cautious about routinely applying adjunct modalities with little or no evidence.

For readers

This masterclass provides a practical, guideline-aligned framework for understanding which knee OA treatments are supported by evidence and which should be abandoned in clinical practice.