Clinical Pearls & Morning Reports
Published January 6, 2021
In recent years, there has been a shift from primarily pharmacologic therapy to nonpharmacologic therapy for osteoarthritis of the knee, owing to the limited benefits of the former and evidence that nonpharmacologic approaches are more likely to relieve symptoms in the long term and to delay or prevent functional decline. Read the NEJM Clinical Practice Article here.
Q: What are some of the risk factors for osteoarthritis of the knee?
A: Factors that have been associated with an increased risk of osteoarthritis of the knee include older age, female sex, overweight or obesity, knee injury, occupational factors (e.g., knee bending, heavy lifting, and squatting), and varus or valgus alignment. Risk is not increased with recreational physical activity.
Q: How is osteoarthritis of the knee typically diagnosed?
A: A medical history and physical examination are typically sufficient to establish the diagnosis of osteoarthritis. Symptoms begin gradually, usually in men in their 40s or older and in women in perimenopause or older. The pain is often dull, involving the whole knee or more localized, increases with joint use, and abates with rest. Findings of osteoarthritis of the knee include crepitus, bony enlargement, reduced knee flexion, flexion contracture, and tenderness. Erythema, warmth, and swelling, if present, are mild. More marked inflammation suggests another process.
A: Exercise is an essential component of the management of osteoarthritis of the knee. Exercise goals include maintaining or improving aerobic fitness, range of motion, and strength and reducing the risk of falls. Studies showing benefit have involved aerobic exercise (e.g., treadmill, track, or community-based walking), strengthening (isokinetic, isometric, or elastic-band exercises), neuromuscular exercise, aquatic activities, balance exercise, and mind–body exercise. In a randomized, single-blind trial comparing tai chi with physical therapy, tai chi led to similar improvements as seen with physical therapy according to a validated osteoarthritis index at 12 weeks and greater improvements in depression and the physical component of quality of life. Exercise therapy is, ideally, initiated and personalized by a physical therapist. In persons with osteoarthritis of the knee who are overweight or obese, weight loss is strongly recommended.
A: A meta-analysis of seven randomized, controlled trials showed a benefit of treatment with topical nonsteroidal antiinflammatory drugs (NSAIDs) similar to that with oral NSAIDs but with fewer adverse effects. Their use should precede use of oral NSAIDs, although they are less practical when more than one joint is involved. When the use of topical NSAIDs is impractical, ineffective, or not preferred, oral NSAIDs are the oral medication of choice in the absence of contraindications; a meta-analysis of nine randomized, controlled trials (excluding trials with very-low-quality ratings) showed small effect sizes for pain and function. Guidelines support the use of nonselective NSAIDs, preferably with proton-pump inhibitors, or cyclooxygenase-2 (COX-2) inhibitors in patients with no coexisting conditions. In patients with cardiovascular coexisting conditions, the use of oral NSAIDs is not recommended. Systematic reviews and meta-analyses of randomized trials of acetaminophen in persons with osteoarthritis of the knee suggest minimal efficacy. Short-term or episodic use of acetaminophen may be considered in persons who cannot use NSAIDs. A recent randomized trial showed that physical therapy was similarly effective in the short term and better in the long term than a glucocorticoid injection. There is insufficient evidence to support a meaningful effect of intraarticular hyaluronic acid; a meta-analysis showed modest effect sizes and a risk of serious adverse events (e.g., injection-site reaction and joint swelling).