Use in traditional medicine
Tiger bone (Hu Gu) is classified as acrid and salty, entering the Liver and Kidneys. It has traditionally been used in Chinese medicine to dispel wind, ease pain and strengthen the sinews and bones (for example rheumatic and arthritic disorders, atrophy and weakness of the back and legs, spasms of the legs etc.). It was traditionally subdivided into head bones (tou gu), neck bones (jing gu), skeletal bones (shen gu) and bones of the extremities (si zhi gu). The latter, especially the patella and tibia, are the most highly prized. 
1. Chinese Herbal Medicine Materia Medica, 3rd edition, by Dan Bensky, Steven Clavey & Erich Stoger, Eastland Press, Seattle, 2004.