Note 10 - Revenue - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue	$ 39,536	$ 31,694	$ 111,973	$ 97,769
Joint Pain Management Therapies [Member]
Revenue	26,153	18,439	69,790	66,168
Joint Preservation and Restoration [Member]
Revenue	11,193	11,715	35,296	26,233
Manufactured Product, Other [Member]
Revenue	2,190	1,540	6,887	5,368
Product [Member]
Revenue	$ 39,536	$ 31,694	$ 111,973	$ 97,769