A COMPARISON OF TWO LEADING INTRA-ARTICULAR HYALURONIC ACID AGENTS IN ATHLETES WITH CHONDRAL DAMAGE OF THE KNEE

Abstract

Viscosupplementation with hyaluronic acid (HA) is an established intervention for pain control in patients with mild to moderate osteoarthritis (OA) of the hip and knee. It is highly concentrated at the surface of the articular cartilage and the superficial layers of the synovial membrane. In the synovial fluid, HA acts as both a lubricant and a shock absorber. Due to the meshwork it forms with aqueous solutions, it acts as a semi-permeable barrier regulating metabolic exchanges between cartilage and the synovial fluid, and a viscoelastic shield around synoviocytes and adjacent nerve endings. Through its molecular size HA hinders the free movement of lytic enzymes and inflammatory mediators, and enhances chondrocyte metabolism. Osteoarthritis is associated with a decrease in concentration and average molecular weight of native HA in synovial fluid.

The mechanism of action of administered intra-articular HA is not completely understood, but as its clinical benefit exceeds its intra-articular presence, it is thought to perhaps induce native biosynthesis of HA and other extracellular matrix components and in particular suppress the inflammatory response and inhibit substance P, in addition to contributing to shock absorption by means of its viscoelastic properties.

Problems include inconvenience, expense and the logistical problems associated with multiple injections, injection technique and level of skill required by the administering physician, variable clinical response and adverse reactions.

In this independent, prospective, randomized trial, we compare efficacy and complications associated with treatment 100 athletes (112 knees) using durolaneTM and synvisc oneTM using the Visual Analogue Score, SF-36 V2 questionaire, and Oxford knee scores. Range of movement and absence from sporting activity is recorded at each visit. These assessments are repeated at 3, 6, 9 and 12 months. Significant improvement is seen in the VAS, SF 36 V2 and Oxford Knee Scores (p=0.01) and reduction in the use of analgesics and anti-inflammatories is seen with both products at 3 months post injection, with a significant advantage to the duro-lane group (p=0.001). At 6 months, this difference is extended even further. A small but statistical difference is noted in the time taken for the athlete to return to sporting activity following a rest period due to pain. Adverse reactions occur significantly less with the more effective product. We conclude that intra-articular HA a useful intervention in patients with mild to moderate OA of the knee, can produce sustained pain relief at 6 months, and can reduce the requirement for analgesia and anti-inflammatory medication during this time.