Physical therapy reduces pain in adults with knee osteoarthritis

1. Physical therapy was shown to significantly reduce pain in patients with knee osteoarthritis compared to the patients who received an intraarticular glucocorticoid injection.

2. Physical therapy significantly improved functionality compared to treatment with an intraarticular glucocorticoid injection for osteoarthritis of the knee.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Osteoarthritis of the knee is a leading cause of disability with current treatments focus on the management of symptoms. One such treatment is an intraarticular glucocorticoid injection; however, reports present conflicting data regarding the extent and duration of symptom relief. Despite guidelines recommending physical therapy, the use of the treatment has declined in favor for glucocorticoid injection therapy. As such, this study compared the effectiveness of glucocorticoid injection to physical therapy in patients diagnosed with osteoarthritis of the knee. Participants were randomized to receive a glucocorticoid injection or to undergo physical therapy. The study concluded that patients undergoing physical therapy had a lower Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, indicating less pain, compared to the glucocorticoid injection therapy. Functional task outcomes for patients who underwent physical therapy was improved compared to those who received glucocorticoid injection.  This randomized trial was limited by the patient selection because patients were active-duty or retired members. Due to the physicality of combat training, the osteoarthritis in the knee can be more severe than that in the general public. As such, these results may not be generalizable to the civilian population. Further, the physical therapy group had more patients with severe osteoarthritis compared to the glucocorticoid injection group. This imbalance of arthritis grade amongst the participants between both groups may undermine the study conclusions. Nonetheless, this study was strengthened by the extended participant follow-up of one year and the functional task data along with the WOMAC score indicating pain. For physicians, these findings provided data to recommend physical therapy and lifestyle changes instead of glucocorticoid injection for patients diagnosed with osteoarthritis of the knee as evidence-based medicine.

Click to read the study in NEJM

Relevant Reading: The Efficacy and Duration of Intra-articular Corticosteroid Injection for Knee Osteoarthritis: A Systematic Review of Level I Studies

In-Depth [randomized controlled trial]: This randomized control trial enrolled 156 patients at two army medical centers in Tacoma, Washington, and San Antonio, Texas. The study population included active-duty, retired service members, and their family members (≥ 38 years of age). Inclusion criteria included: met clinical classification criteria for osteoarthritis of the knee set by the American College of Rheumatology and radiographic evidence of osteoarthritis. Exclusion criteria included: previous glucocorticoid injection or physical therapy for knee pain in the previous 12 months and no radiographic evidence of osteoarthritis. The patients were randomized to physical therapy or intraarticular glucocorticoid injection treatment in a 1:1 ratio. The primary outcome was the total score on the WOMAC at one year ranging from 0 to 240. A higher WOMAC score indicated worse pain and increased stiffness. Additionally, the secondary outcomes included two functional tasks with the Timed Up and Go test and Alternate Step Test. For the primary outcome, patients in the physical therapy group had a mean (± standard deviation) WOMAC score, at one year, of 37.0±30.7. The patients in the glucocorticoid injection treatment had a mean WOMAC score of 55.8±53.8. The mean between-group difference for the WOMAC score of 18.8 points (0.008, 95% confidence interval [CI], 5.0 to 32.6). The secondary outcome measured the time to complete functional tasks in seconds. Both outcomes were measured at baseline and the one-year follow-up visit. The mean between-group difference for the Timed Up and Go test was 0.9 seconds (0.005, 95% CI, 0.3-1.5). The mean between-group difference for the Alternate Step Test was 1.0 second (0.003, 95% CI, 0.3-1.6). On average, in both functional tests the patients in the glucocorticoid injection group took longer to complete the task than the physical therapy group. Taken together, the study concluded physical therapy for patients diagnosed with knee osteoarthritis significantly reduced pain and increased functionality compared to those who received glucocorticoid injection treatment.

Image: PD

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