title: Hyaluronans: is clinical effectiveness dependent on molecular weight?
abstract: The original rationale for viscosupplementation with hyaluronans was fluid replacement, suggesting that the most viscous materials (eg, those of highest molecular weight [MW]) would provide the most clinical benefits. However, it has become clear that mechanisms of action for osteoarthritis pain management are not only mechanical but also biological. After intra-articular injection, hyaluronans exert a range of biological actions within the joint. Although high- and low- to mid-MW hyaluronans (but not hyaluronans <500 kDa MW) are more or less active (depending on the specific effect examined), it is not known which actions are clinically meaningful. There is no evidence for a difference between hyaluronan products in clinical efficacy measured as pain relief, but investigators in several preclinical studies evaluating joint-structure modification in osteoarthritis models have reported advantages to using low- to mid-MW hyaluronans.
authors.affiliation: Nonoperative Sports Medicine, Rothman Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Vitanzo
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Sennett
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use; D007270:Injections, Intra-Articular; D008970:Molecular Weight; D020370:Osteoarthritis, Knee / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy*; D011956:Receptors, Cell Surface / Q000187:drug effects; D013582:Synovial Fluid / Q000187:drug effects
chemical_list: D000276:Adjuvants, Immunologic; D011956:Receptors, Cell Surface; D006820:Hyaluronic Acid