Intra-articular Hyaluronic Acid Injection for Therapy-resistant Patellofemoral Pain Syndrome

Patellofemoral pain syndrome (PFPS) is the most common overuse injury seen in the athletic population, particularly amongst runners. The standard of care treatment for PFPS is a comprehensive active rehabilitation program. Eighty percent of patients with PFPS report improvement in their symptoms with such a program. Unfortunately, the remaining twenty percent fail to achieve adequate symptom relief with rehabilitation alone. Considering the enormous number of individuals running for fitness, PFPS represents a significant challenge to public health as the investigators strive to encourage active living in our society. A relationship between PFPS and the development of patellofemoral osteoarthritis (PFOA) has been suggested in scientific literature. Given that intra-articular viscosupplementation (hyaluronic acid) injections have shown clinically significant symptom improvement in knee osteoarthritis, and PFPS is likely on the same spectrum, the investigators propose a trial for therapy-resistant PFPS. Hyaluronic acid is a naturally occurring molecule found in the synovial fluid of freely movable joints (such as the knee). It is believed to contribute to lubrication and cushioning in these joints. The composition of synovial fluid within arthritic joints is altered, resulting in reduced fluid viscosity and elasticity. One modern formulation of hyaluronic acid is Hylan G-F 20 (Synvisc-One, Sanofi Canada). This treatment is offered as a single injection and will be utilized in this clinical trial.