Symptomatic chondral and osteochondral defects affect a large and growing number of patients. A safe and effective surgical treatment for large articular defects is osteochondral allograft (OCA) transplantation. One of the major causes of failure for OCA transplantation is loss of essential chondrocyte viability during the preservation and storage period. It is also possible that metabolic responses of the OCA when transitioning from storage temperature to body temperature may contribute to mechanisms causing failure. The present study was designed to compare MOPS SM -preserved OCAs to those stored using the current standard of care (SOC) method with respect to metabolic responses when rewarmed for transplantation to and maintenance at body temperature (37˚C). It was theorized that grafts stored using the MOPS SM protocol would maintain significantly higher chondrocyte viability and produce significantly lower levels of inflammatory mediators and degradative enzymes, and significantly higher levels of chemokines compared to grafts stored using the SOC protocol. Left over SOC and MOPS SM -stored OCA tissues were collected after surgery, and cartilage explants were cultured for 6 days. Media was analyzed for biomarkers using commercially available assays. Cartilage from SOC grafts released significantly higher levels of PGE2, MMP-1, MMP-2, and MMP-13, and significantly lower levels of IL-8 and Groa, compared to cartilage from MOPS SM -stored grafts. Clinical significance: These data suggest that OCAs stored using the MOPS SM protocol have potentially less detrimental initial inflammatory and degradative responses to re-warming for transplantation compared to OCAs stored using the current tissue bank protocols. ß