The effects of exercise and intra-articular injections versus exercise alone for the treatment of knee osteoarthritis: A scoping review of the evidence

Objective: Current treatment for knee Osteoarthritis (OA) includes exercise and intra-articular injections with corticosteroid (CS), hyaluronic acid (HA), etc., which address OA-related pain and functional limitation. While these interventions can be given together, little is known about the efficacy of a multi-modal approach. The purpose of this scoping review is to examine studies that compare combining exercise and intra-articular knee injections to exercise alone for the management of knee OA. Methods: A search was performed using PubMed, CINAHL, and Clinicaltrials.gov with MeSH terms "knee osteoarthritis" AND "exercise" AND "injections". Abstracts were screened to meet inclusion criteria of both intervention groups including exercise and one group receiving an injection for treatment of knee OA. Full text articles were screened to meet inclusion criteria and rated using the Pedro Scale. Results: 11 studies that met inclusion criteria. The included studies utilized CS, hyaluronic acid (HA), and Bone Marrow Concentrate (BMC), botulinum toxin A, or a combination of dextrose and lidocaine injections. Most studies included supervised exercise interventions with all studies including strengthening of the quadriceps. CS and exercise compared to exercise alone showed similar improvements in pain. The HA injection studies yielded mixed results with two studies finding HA and exercise was not superior than exercise alone while two other studies found that HA and exercise were superior. Conclusion: There was a paucity of literature investigating multimodal approaches. Most of the included studies did not find superior effects of adding a knee injection to exercise compared to exercise alone for knee OA.