By Seema Gupta, MD, MSPH

Clinical Assistant Professor, Department of Family and Community Health, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV

Dr. Gupta reports no financial relationships relevant to this field of study.

SYNOPSIS: In a small, randomized, controlled trial of patients with knee osteoarthritis, those who received physical therapy reported less pain and functional disability at one year than those who received one or more glucocorticoid intra-articular injections.

SOURCE: Deyle GD, Allen CS, Allison SC, et al. Physical therapy versus glucocorticoid injection for osteoarthritis of the knee. N Engl J Med 2020;382:1420-1429.

Knee osteoarthritis (KOA) is the most prevalent form of arthritis and a common cause of disability, the incidence of which increases with age. In the United States, KOA affects between 7% and 33% of the population.1 Often, a comprehensive management plan for KOA may include educational/behavioral training (including weight loss when applicable), psychosocial techniques, and physical interventions, as well as topical, oral, and intra-articular medications. Physical therapy is one of the most important nonpharmacological KOA treatments. It is cost-effective and safe, with demonstrated efficacy in reducing the need for pain medication and improving knee function.2 When it comes to less knee pain, high-quality evidence indicates exercise therapy can provide short-term benefits that can be sustained between two and six months after a patient ends formal treatment.3 Interestingly, the magnitude of this treatment effect has been found to be similar to estimates reported for nonsteroidal anti-inflammatory drugs. However, evidence also indicates lifestyle counseling and physical therapy may be underused in these patients. Meanwhile, pain medication prescriptions are on the rise.4 While intra-articular glucocorticoids injections are used as a common primary treatment for pain relief in KOA, whether there are clinically important benefits of intra-articular corticosteroids after one to six weeks remains uncertain.5 There also are no clear data to recommend use of glucocorticoid injections as an add-on to physical therapy.

To compare their relative efficacy, Deyle et al compared physical therapy to glucocorticoid injections for KOA patients in a U.S. military health system primary care setting. The authors randomly assigned 156 patients with symptomatic and radiographic OA in one or both knees to receive a glucocorticoid injection or to undergo physical therapy over 12 months. The mean age was 56 years, and the primary outcome was the total score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; scores range from 0-240. The higher the score, the worse the stiffness, pain, and function).

Patients who underwent physical therapy reported less pain and functional disability after one year than those who received a glucocorticoid injection. The mean baseline WOMAC scores in the glucocorticoid injection group were 108.8 ± 47.1. In the physical therapy group, the mean baseline WOMAC scores were 107.1 ± 42.4. After one year, the mean scores declined to 55.8 ± 53.8 in the injection group and to 37.0 ± 30.7 in the therapy group (mean between-group difference, 18.8 points; 95% confidence interval, 5.0-32.6).

COMMENTARY

Not surprisingly, physical therapy provided better benefits vs. glucocorticoid injections. The implication is as simple as it is clear: Patients with KOA should be referred for physical therapy as the first step. Intra-articular injections may play a role in acute exacerbations but should not be considered as a substitute for a robust physical therapy program. In fact, this approach is not only likely to produce immediate and lasting benefits, it may even avert using pain medications on some occasions. Aligning payment incentives also may go a long way to change clinician behavior to ensure patients are receiving the best evidence-based care for a common problem.

REFERENCES

  1. Lawrence RC, Felson DT, Helmick CG, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis Rheum 2008;58:26-35.
  2. Juhl C, Christensen R, Roos EM, et al. Impact of exercise type and dose on pain and disability in knee osteoarthritis: A systematic review and meta-regression analysis of randomized controlled trials. Arthritis Rheumatol 2014;66:622-636.
  3. Fransen M, McConnell S, Harmer AR, et al. Exercise for osteoarthritis of the knee: A Cochrane systematic review. Br J Sports Med 2015;49:1554-1557.
  4. Khoja SS, Almeida GJ, Freburger JK. Recommendation rates for physical therapy, lifestyle counseling and pain medications for managing knee osteoarthritis in ambulatory care settings: A cross-sectional analysis of the National Ambulatory Care Survey (2007-2015). Arthritis Care Res (Hoboken) 2020;72:184-192.
  5. Jüni P, Hari R, Rutjes AW, et al. Intra-articular corticosteroid for knee osteoarthritis. Cochrane Database Syst Rev 2015:CD005328.