Collagen-platelet rich plasma hydrogel enhances primary repair of the porcine anterior cruciate ligament. - Murray,M.M.; Spindler,K.P.; Abreu,E.; Muller,J.A.; Nedder,A.; Kelly,M.; Frino,J.; Zurakowski,D.; Valenza,M.; Snyder,B.D.; Connolly,S.A. (J Orthop Res, 2007)