Osteoarthritis (OA) is the most common joint disorder, it is a chronic arthropathy of one or more joints characterized by degeneration and loss of joint cartilage, along with other joint changes, including bone hypertrophy.1
A progressive disease that occurs mainly in the latter half of life, OA can be progressively disabling.
Patients mainly seek medical care because of the intractable pain caused by OA.2 It often becomes symptomatic in the fifth and sixth decades of life and is almost universal by age 80.3
In individuals younger than 40 years, OA occurs more frequently in men and is primarily a result of trauma.
Occurrence predominates in women from age 40 to 70 years, after which men and women are equally affected.
The pathogenesis and pathophysiology of OA is complex and affects several systems, beginning with the articular cartilage, which is a complex material synthesized and maintained by its living component, the chondrocyte.5
Water makes up 65% to 85% of cartilage and interacts with matrix proteoglycans, matrix collagens, hyaluronic acid, and other components. Healthy cartilage is balanced between matrix synthesis and matrix degradation.
In OA, regardless of the involved joint, matrix degradation overtakes matrix synthesis. Articular cartilage degradation is associated with abnormal joint stresses over time.
Stresses include obesity, which can place an abnormal load on the knee joint, microfractures in the subchondral bone, and trauma.
Concurrent factors, including normal aging, metabolic diseases, inflammation, and immune system malfunctions, lead to biochemical changes that also result in cartilage degradation.5
Projected burden of osteoarthritis in Australia
The number of people with OA is expected to increase nationally from almost 2.2 million in 2015 to almost 3.1 million Australians in 2030.
Health care costs for OA were estimated to be over $2.1 billion in 2015; by the year 2030, these are forecast to exceed $2.9 billion ($970 for every person with the condition).6
The role of Hyaluronic Acid (HA)
Normal articular cartilage is composed of an extracellular matrix and chondrocytes, the cells that produce and maintain the cartilage.7
Within the matrix, water, collagen fibers, and proteoglycan macromolecules - large molecules containing protein and a type of polysaccharide - are cross-linked into an integrated network.
The backbone of each proteoglycan network is a large molecule of hyaluronic acid, also called hyaluronan or sodium hyaluronate.5
The interaction of these molecules forms the structural network providing cartilage with its most important biomechanical properties, compressibility and elasticity.5
High concentrations of hyaluronic acid are also found in the synovial fluid.8
In healthy joints, this highly viscous, shock-absorbing lubricant is contained within the joint capsule and helps enable articulation of the joint.
The synovial fluid in osteoarthritic joints contains a decreased concentration and molecular weight of hyaluronic acid compared with those found in healthy joints.8
The synovial fluid in osteoarthritic joints does not have the same elastic and viscous qualities as those of a healthy joint.
Viscosupplementation as a treatment of OA
Viscosupplementation with an elastoviscous fluid containing polymers of hylan derivatives of natural glycosaminoglycan hyaluronan is indicated for treating pain of osteoarthritis of the knee that has not responded to or is contraindicated for conservative nonpharmacologic therapy and traditional analgesics. These analgesics include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2 (COX-2) inhibitors.9
A systematic review of meta-analyses comparing Intra-articular HA treatment with other IA therapies and oral NSAIDs concluded HA to be a viable treatment option for knee OA, producing improvements in pain and function that can persist for up to 26 weeks, and demonstrating a good safety profile.10
Monovisc is a newly available Hyaluronic Acid viscosupplement in Australia. It is a single, high dose viscosupplement injection for the treatment of OA in all synovial joints.
Monovisc is manufactured from ultra-pure, high molecular weight sodium hyaluronate produced by bacterial fermentation and is a non-avian HA.11
Preclinical studies suggest that there is an optimal molecular weight of HA required to stimulate native HA production. Monovisc falls into this category of having Optimal molecular weight.12
Monovisc lubricates, cushions and protects the joint, bringing pain relief that lasts up to six months.13
1. Beers MH, Porter RS, Jones TV, Kaplan JL, Berkwits M, eds. Osteoarthritis. The Merck Manual of Diagnosis and Therapy. 18th ed.
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3. Gabriel SE, Crowson CS, O’Fallon WM. Costs of osteoarthritis: estimates from a geographically defined population. J Rheumatol. 1995;22(suppl 43):23-25.
4. Lanes SF, Lanza LL, Radensky PW, et al. Resource utilization and cost of care for rheumatoid arthritis and osteoarthritis in a managed care setting. Arthritis Rheum. 1997;40:1475-81.
5. Mandelbaum B, Waddell D. Etiology and pathophysiology of osteoarthritis. Orthopedics. 2005;28(suppl):S207-S214.
6. Projected Burden of Osteoarthritis and Rheumatoid Arthritis in Australia: A Population-Level Analysis. Ackerman IN, Pratt C, Gorelik A, Liew D. Arthritis Care Res (Hoboken). 2017 Sep 12. doi: 10.1002/acr.23414
7.Moskowitz RW, Kelly MA, Lewallen DG. Understanding osteoarthritis of the knee—causes and effects. Am J Orthop. February 2004;33(2 suppl):5-9.
8. Kaiyama J, Uzuki M. Alteration of hyaluronic acid property in synovial fluid of patient with osteoarthritis. J Iwate Med Assoc. 2006;58:9-21.
9. Arnold W et al. Viscosupplementation: managed care issues for osteoarthritis of the knee. J Manag Care Pharm. 2007 May;13(4 Suppl): S3-19
10. Campbell KA, Erickson BJ, Saltzman BM, et al. Is local viscosupplementation injection clinically superior to other therapies in the treatment of osteoarthritis of the knee: a systematic review of overlapping meta-analyses. Arthroscopy 2015; 31: 2036–2045.
11. Monovisc IFU
12. Smith MM, Ghosh P. The synthesis of hyaluronic
acid by human synovial fibroblasts is influenced by the nature of the hyaluronate in the extracellular environment. Rheumatol Int. 1987;7(3):113-22
13. Dernek B et al Efficacy of single dose HA products with 2 different structures in patients with early-stage knee osteoarthritis. J. Phys Ther. Sci.28:3036-3040,2016