Gw. White et al., Evaluation of the efficacy of various preparations of sodium hyaluronate in an induced equine carpitis model, J EQUINE V, 19(5), 1999, pp. 331-337
A study was performed to evaluate the efficacy of three formulations of sod
ium hyaluronate in an induced carpitis model. Sixteen healthy mature Quarte
r Horse type horses free of lameness and carpal disease had carpitis induce
d by injection of Complete Freund's Adjuvant in the left radial carpal join
t, Five days after model induction the horses were assigned to four groups
of four horses each and treated with either placebo, intravenous sodium hya
luronate, intraarticular low molecular weight sodium hyaluronate or intraar
ticular high molecular weight sodium hyaluronate,
Lameness variables and synovial fluid variables were measured prior to mode
l induction, just prior to treatment and across 16 weeks post treatment. Ra
diographs were taken prior to model induction and at six and 16 weeks post
treatment. An attempt to evaluate exercise tolerance was also made, Gross a
nd histopathology were performed on one randomly selected animal from each
treatment group at week 16,
Results confirmed efficacy of all formulations of sodium hyaluronate in the
relief of lameness as compared to placebo. Model induction led to a dramat
ic decrease in synovial fluid hyaluronate concentration and mean molecular
weight. All treatments restored the hyaluronate concentrations to premodel
normal levels and all treatments led to an increase in model induced defici
ts in mean molecular weight of synovial fluid hyaluronate; only the high mo
lecular weight intraarticular preparation restored the mean molecular weigh
t to premodel normal levels.
Statistically significant findings in the lameness data along with trends s
een in synovial fluid parameters support improved efficacy and longer durat
ion of efficacy for the high molecular weight sodium hyaluronate preparatio
n. Statistical weaknesses due to small group sizes and design flaws in the
study prevented definitive conclusions.