Note 11 - Revenue - Product Revenue by Product Group (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue	$ 30,678	$ 30,418	$ 66,075	$ 55,141
Joint Pain Management Therapies [Member]
Revenue	22,247	26,632	47,730	49,482
Orthopedic Joint Preservation and Restoration Care [Member]
Revenue	6,622	802	14,518	966
Manufactured Product, Other [Member]
Revenue	1,809	2,979	3,827	4,682
Product [Member]
Revenue	$ 30,678	$ 30,413	$ 66,075	$ 55,130