Viscosupplementation and Synovial Fluid Rheology: A Hidden Risk for Bacterial Biofilm Formation in Joint Infections?

Synovial fluid (SF) plays a critical role in joint lubrication, load distribution, and maintaining homeostasis within the synovial cavity. Its rheological properties, primarily influenced by hyaluronic acid (HA) and other macromolecules, are essential for normal joint function. However, alterations in the physicochemical characteristics of SF can occur due to septic conditions, including septic arthritis (SA) and periprosthetic joint infections (PJIs), which significantly impact joint health. Bacterial colonization in infected joints often leads to the formation of biofilms, microbial aggregates encased in an extracellular matrix, which confer resistance to antibiotics and host immune responses. Biofilm formation in SF-altered environments is a major challenge in treating joint infections, particularly in patients with prosthetic implants. , primarily through intra-articular hyaluronic acid (HA) injections, has been widely used to restore SF viscosity and function in degenerative joint diseases. More recently, polyacrylamide (PAA)-based gels have emerged as an alternative viscosupplementation strategy. However, concerns have been raised regarding the potential impact of viscosupplements on biofilm formation and bacterial adhesion in septic joints, as changes in SF viscosity and composition may influence bacterial colonization and persistence. This review aims to assess the interaction between viscosupplementation and biofilm formation in septic joint pathologies, examining the effects of HA and PAA on SF rheology and bacterial adhesion. Understanding these interactions is crucial for optimizing therapeutic strategies and mitigating the risk of biofilm-associated infections in patients undergoing viscosupplementation.