Exercise and Education for Knee Osteoarthritis — An Unusual Randomized Trial

Proving that exercise programs improve symptoms of knee osteoarthritis (OA) is challenging; those interventions can't be blinded in clinical trials, and substantial placebo effects are likely. In this novel randomized trial that involved 206 patients with symptomatic knee OA, researchers sought to isolate the placebo response.

Patients were randomized to an 8-week exercise and education program (with 15 hours of contact with physical therapists) or to 4 intraarticular saline injections, spread over 8 weeks; the latter intervention was considered to be inert placebo. The researchers noted that when saline has been used as a placebo control in randomized trials of injection therapies for knee OA, the magnitude of improvement with saline has be…