Lipid oxidation may reduce the quality of a fresh-frozen bone allograft. Is the approved storage temperature too high?

Background International standards indicate that bone allografts for human use should be stored in a -40°C or colder environment and the storage time should be up to 5 years. Bone allografts contain lipids which oxidate and become toxic with time. Material and methods We determined lipid oxidation in femoral head bone allografts by headspace gas chromatography at different storage temperatures and storage times. Results We found that lipid oxidation in fresh-frozen bone allograft was influenced by storage temperature and storage time. Lipid oxidation was significantly more rapid at -30°C than at -70°C. Even at -70°C, however, some oxidation occurred but it was quite minimal after 3 years. Interpretation Because of the negative effects of lipid oxidation, we recommend a storage temperature of -70°C or lower for bone allografts.