through reducing bone remodeling, promote synthesis of endogenous HA,
and inhibit mediators of inflammation, specifically PGE2 and MMPs. In
comparison with HA in an OA model, PSGAGs were demonstrated to reduce
joint effusion and reduce synovial membrane vascularity and subintimal
fibrosis better than HA,while HA was more protective against cartilage
fibrillation. Neither HA nor PSGAGS improved lameness (Frisbie et al. 2009).
Intra-articular administration has been associated with joint infections due to a
reduction in complement activity in the joint. Intra-articular administration is
now most commonly combined with 125 mg of amikacin or 150 mg gentamicin
to deter any infection, and this practice appears to be effective.
A heparinoid effect has also been documented that may cause acute
hemarthrosis and usage should be avoided after recent joint hemorrhage or
surgery.
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Variable clinical regimes have been suggested:
1. 5 to 7 intra-articular injections over 5 to 7 weeks
2. 1 to 2 intra-articular injections 10 to 14 days apart
3. 1 intra-articular injection followed by a seven week IM course
4. A recent study by Kristiansen and Kold (2007) suggests a favorable
outcome with 3 weekly intra-articular injections of 250 mg PSGAG in
the distal interphalangeal joint combined with an 8-week programme of
stall rest and hand walking followed by a graduated return to exercise.
Polyglycan
Polyglycan®, is a patented formulation comprised of hyaluronic acid,
chondroitin sulfate, and N-acetyl-Dglucosamine, and has been used clinically
in horses intra-articularly for viscosupplementation. This product is currently
used extensively in equine practice though scientific evidence of efficacy is
lacking.
Stanosolol
Stanasolol is an anabolic steroid that reportedly has both anti-inflammatory
and regenerative effects in an ovine model of osteoarthritis (Spadari et al.
2013). In a recent report 78% of Thoroughbred racehorses with joint injuries
that had become unresponsive to other treatments were able to resume their
previous level of performance following intra-articular medication (Ramzan et
al. 2012).
Polyacrylamide Hydrogels
Polyacryl amid hydrogel has also shown beneficial effects in a goat model of
osteoarthritis (Tnibar et al. 2014). The same product has recently been
injected into the distal interphalangeal joints of 12 Sport horses with refractory
osteoarthritis which resulted in 8 horses becoming sound, 2 horses improved
and 2 horses remaining unchanged. The beneficial effects of the intra-articular
hydrogel were thought to arise from the non-degradable nature of the
hydrogel resulting in longer lasting remission of lameness than with other
hydrogels like hyaluronic acid (Janssen et al. 2012).
15-‐18
February
2016
East
London
Convention
Ce ntre,
East
London,
South
Africa
158