Viscosupplementation

Question 1

What is hyaluronic acid?

Answer 1

• naturally occurring glycosaminoglycan
• provides viscoelastic properties in synovial fluid and cartilage i.e. lubrication, scock absorbtion and metabolic exchange between cartilage and synovial fluid
• the various products have different molecular weights, generally large.

Question 2

Hyaluronic acid

effects

Answer 2

• restore viscoelasticity and flow of synovial fluid
• normalises the metabolic process eithin the joint
• relieves joint pain
• has role in promoting early inflammatory process, formation af granulation tissue and wound healing
• HA fragments can induce inflammation

Question 3

What does OA do to the joint?

Answer 3

• the concentration and molecular weight of endogenous hyaluronic acid are decreased
• synovial fluid becomes fragmented and depolymerised
• biomechanical loading of the joint increases leading to cartilage breakdown and erosion of synovial lining
• the viscoelastic properties of the synovial fluid is reduced

Question 4

What do viscosupplementation do to the joint?

Answer 4

• enhanced HA and proteoglycan synthesis
• reduce production and activity of proinflammatory mediators and metalloproteinases
• altered immune cell function
• inhibition of proteolytic enzyme diffusion into cartilage
• protection of endogenous cartilage proteoglycan
• stimulation of HA from synovial fibroblasts

Question 5

HA

potential use

Answer 5

• provide symptom relief in osteoarthritis
• (may be) slow down progress in osteoarthritis
• use in tendinopathy

Question 6

HA

evidence

Answer 6

• gives similar pain relief to steroids, slower onset longer duration. Best in early OA, non inflamed??
• evidence for long term joint protection minimal
• generally safe and well tolerated

Question 7

HA

indications OA knee

Answer 7

• Medium term pain relief 5-13 weeks
• beneficial effect on weightbearing pain
• beneficial effect on function
• longer term benfits compared to IA steroids
• IA steroids have better short term benefits 0-4 weeks
• comparable efficacy to NSAID

Question 8

HA

other joints

Answer 8

increasing evidence for use in hip ankle and shoulder

Question 9

HA

soft tissue

Answer 9

have been trialed in tendinitis and tendinosis with some benefit

Question 10

HA

after injury

Answer 10

• have been used in sports after soft tissue or joint injury to increase speed of recovery.
• similarly post arthroscophy

Question 11

HA

side effects

Answer 11

• local pain and swelling for 24 hours following injection

Question 12

HA

note

Answer 12

• expensive compared to steroids
• require multiple injections
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