Non-cryoconserving storage strategies for fresh osteochondral allografts

The clinical outcome of fresh allogeneic osteochondral allografts (OCA) is greatly dependent on the number of viable chondrocytes at the time of implantation. The selection and preparation of a suitable recipient can be very time-consuming and the number of tissue donors is greatly limited; therefore, the preservation of high allograft viability before transplantation is a focal point of current research. The objective of this review is to give an overview of established storage strategies for OCA and to serve as a decision-making aid for German clinics in the choice of a suitable storage strategy. A search of the literature published between January 2002 and May 2017 was independently performed by two persons with respect to original works on storage strategies of OCA with a focus on storage medium, use of fetal bovine serum, storage temperature and change of medium. A total of 20 suitable studies were selected for this review. Based on the current studies a clearly superior storage solution could not be identified; however, storage at 4 A degrees C seems to give better results with respect to cell viability than storage at 37 A degrees C. High chondrocyte viability rates after 28 days of storage were also achieved using media without the addition of fetal bovine serum. A major difficulty in comparing the relevant studies on storage solutions is that multiple aspects in the study design varied between the studies. Due to this no definite conclusion on what the ideal storage strategy should look like could be drawn. Further studies are needed to conclusively show whether cell culture medium-based storage solutions are truly superior to those based on Ringer-lactate solutions.