Table 5. Comparison of WOMAC score of HA injection vs. NSAID group.

WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index, HMW: high molecular weight, HA: hyaluronic acid, NSAID: nonsteroidal anti-inflammatory drug, SD: standard deviation

WOMAC score	Single intra-articular injection of HMW HA mean ± SD	NSAID group mean ± SD	t-test value	p-value
At week 0	77.9 ± 6.4	80.2 ± 6.2	-1.41	0.334
At week 3	71.3 ± 6.7	74.9 ± 4.8	-2.40	0.019
At week 6	68.3 ± 7.2	72.5 ± 4.9	-2.63	0.044
At week 9	66 ± 7.1	70.2 ± 4.9	-2.67	0.016
At week 12	61.7 ± 6.5	68.2 ± 4.5	-4.52	<0.001