@article {369, title = {The effects of freeze-drying and rehydration on cancellous bone}, journal = {Clin Orthop Relat Res}, year = {1993}, note = {Conrad, E U Ericksen, D P Tencer, A F Strong, D M Mackenzie, A P United states Clinical orthopaedics and related research Clin Orthop Relat Res. 1993 May;(290):279-84.}, month = {May}, pages = {279 - 84}, edition = {34090}, abstract = {Processing technique significantly affects the strength and stiffness of bone for use as a structural alloimplant in reconstructive surgery. The effects of the rehydration of freeze-dried human cancellous bone were studied using 14-mm-diameter cancellous dowels taken from matched cadaveric sites. Three different methods of rehydration were evaluated and compared with unrehydrated freeze-dried and frozen grafts. All samples were biomechanically tested in anatomically matched pair groups to determine compressive strength and stiffness. The strength of each tested graft was expressed as a percentage of its matched pair control. Freeze-dried grafts rehydrated for 24 hours compared with frozen grafts showed no significant difference in mean compressive strength (92.6\% +/- 13.3\% of control). Analysis of in vacuo versus ex vacuo rehydration at one hour showed a 38\% greater mean compressive strength and a 42\% greater mean stiffness for the ex vacuo group. Unrehydrated grafts appeared to be both stronger and stiffer than their rehydrated counterparts. These results suggest that the rehydration of freeze-dried grafts may adversely affect graft strength and stiffness. Rehydration under a negative pressure may proceed more rapidly than the process at atmospheric pressures. These findings limit the acceptability of freeze-dried grafts as structural implants.}, keywords = {*Bone Transplantation, *Fluid Therapy, *Freeze Drying, Adolescent, Adult, Femur, Humans, Middle Aged, Tibia}, issn = {0009-921X (Print) 0009-921X (Linking)}, author = {Conrad,E. U. and Ericksen,D. P. and Tencer,A. F. and Strong,D. M. and Mackenzie,A. P.} }