Successful transpedicular lumbar interbody fusion by means of a composite of osteogenic protein-1 (rhBMP‐7) and hydroxyapatite carrier. A comparison with autograft and hydroxyapatite in the sheep spine. - Blattert,T.R.; Delling,G.; Dalal,P.S.; Toth,C.A.; Balling,H.; Weckbach,A. (Spine, 2002)