Viscosupplementation Agents

This chapter provides an overview of viscosupplementation, a procedure involving the injection of hyaluronic acid (HA) into joints to alleviate inflammation and pain caused by chondral changes. The rationale behind the use of HA is explored, including its ability to enhance synovial fluid viscoelasticity and to regulate pro-inflammatory factors. Furthermore, a variety of available HA products are discussed, highlighting their differences in origin, preparation, molecular weight, and related rheological characteristics. Moreover, the mechanical and biochemical mechanisms of action of viscosupplementation are outlined, as well as the contraindications and adverse events associated with the procedure. Additionally, the existing evidence regarding the use of HA will be specified, noting the divergent recommendations found in reputable guidelines, as well as emphasizing the conflicting findings in the literature. Finally, the applications of viscosupplementation and their evidence for various joints are summarized. Therefore, this chapter aims to shed a light on the reasoning behind the varying approaches to its use in clinical practice, highlighting the need for high-quality research to assess the effectiveness and clinical benefits of HA in osteoarthritic joints.