Allogenic serum improves cold preservation of osteochondral allografts.

Abstract

Although several types of culture medium have been used for preservation of osteochondral allografts, the viability of chondrocytes decreases with increasing storage duration. We previously showed the University of Wisconsin solution is more suitable for graft preservation than culture medium. We determined whether the addition of allogenic serum to University of Wisconsin solution increases chondrocyte survival during prolonged storage of osteochondral allografts. Osteochondral tissue samples harvested from the distal femora of rats were preserved in University of Wisconsin solution supplemented with 0%, 1%, 10%, and 50% allogenic serum at 4 °C for 14 days. Cell viability and chondrocyte degenerative changes of the samples then were assessed using a tetrazolium assay and histologic methods. We also evaluated time-dependent changes in cell viability and histologic findings of samples preserved for 7, 14, and 21 days in University of Wisconsin solution supplemented with or without 10% allogenic serum. After 14 days of preservation, osteochondral tissue samples maintained in University of Wisconsin solution containing 10% or greater allogenic serum exhibited the highest cell viability and lowest degenerative changes in chondrocytes. In the evaluation of time-dependent changes, we found the chondrocyte degenerative changes were greater in cartilage preserved in University of Wisconsin solution alone than in University of Wisconsin solution containing 10% allogenic serum after day 7 or later. Our results suggest the addition of 10% allogenic serum to University of Wisconsin solution enhances viability of osteochondral tissue samples. The use of allogenic serum-supplemented University of Wisconsin solution is expected to prolong the duration of osteochondral allograft storage and result in higher-quality grafts.