Background: Intra-articular (IA) injections are commonly used to treat knee arthritis pain; however, whether their efficacy generalizes to ankle arthritis remains debatable. We aimed to evaluate the evidence for IA therapies in the management of this patient population.
Methods: We performed a literature search for observational and randomized controlled trials (RCTs). Treatments included corticosteroids (CS), hyaluronic acid (HA), platelet-rich plasma (PRP), and mesenchymal stem cells (MSC). We extracted study details, patient demographics, treatment characteristics, efficacy outcomes, and safety. When feasible, data from RCTs were meta-analyzed using a random-effects model and 95% confidence intervals (CIs) were calculated. A P value <.05 was considered statistically significant.
Results: We identified 27 studies (1085 patients). Ankle OA, rheumatoid arthritis (RA), and hemophilic arthropathy populations were examined. The majority of studies were observational (20 studies); the only RCTs were those evaluating HA. Case series demonstrated favorable results in terms of symptomatic relief with CS, HA, PRP, and MSC injections; however, the effects of CS may only be short term and the evidence on MSCs was limited to 1 study with 6 ankle OA patients. Pooled results (3 RCTs, 109 patients) suggested significantly improved Ankle Osteoarthritis Scale scores with HA over saline at 6 months, with a mean difference of 12.47 points (95% CI 1.18-23.77, P = .03).
Conclusion: Evidence from small trials favors HA and PRP injections for the treatment of pain associated with ankle osteoarthritis. However, the relative efficacy of all injectable therapies is far from definitive and warrants further high-quality comparative trials.
Level of evidence: Level III, systematic review.
Keywords: ankle; arthritis; corticosteroids; hyaluronic acid; intra-articular injections; mesenchymal stem cells; meta-analysis; platelet-rich plasma; systematic review; viscosupplementation.