Note 11 - Revenue - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 31,694	$ 29,697	$ 97,769	$ 84,838
Joint Pain Management Therapies [Member]
Revenue	18,439	27,581	66,168	77,063
Orthopedic Joint Preservation and Restoration Care [Member]
Revenue	11,715	544	26,233	1,510
Manufactured Product, Other [Member]
Revenue	1,540	1,490	5,368	6,172
Product [Member]
Revenue	$ 31,694	$ 29,615	$ 97,769	$ 84,745