CLINICAL QUESTION

Is physical therapy (PT) effective for osteoarthritis (OA) knee pain in adults?

EVIDENCE-BASED ANSWER

Exercise therapy with strength, aerobic, or aquatic PT may decrease pain due to knee OA in the short term (6–18 weeks). Improvements may persist for 1 year but typically are diminished by 18 months. (Strength of Recommendation [SOR]: B, systematic review of randomized controlled trials [RCTs], individual RCT.) PT results in greater pain relief for 1 year than glucocorticoid knee injections. (SOR: B, RCT.)

EVIDENCE SUMMARY

A 2019 systematic review and meta-analysis of 77 RCTs (N = 6,472) compared several exercise interventions with usual care for the treatment of hip and knee OA.¹ These interventions focused on strength and aerobic training exercises. Analysis of the aggregated RCTs showed a moderate effect on overall pain at 8 weeks with exercise compared with usual care (38 trials; n = 2,415; effect size = 0.54; 95% CI, 0.40 to 0.67). The effect was greater for knee pain (55 trials; n = 3,750; effect size = 0.64; 95% CI, 0.51 to 0.78) than hip pain (eight trials; n = 703; effect size = 0.17; 95% CI, –0.17 to 0.51). The effect decreased gradually over several months until there was no statistical difference between exercise and usual care at 18 months.