An osteochondral allograft is transplant of a plug of bone and cartilage from a donor into a prepared matching defect in the patient.
Viability of allograft plugs
This technique is usually reserved for large cartilage defects, where the cartilage damage is full thickness. Fresh allograft is purchased from a tissue bank as a block of bone and cartilage, from which the surgeon harvests the plug. The success of the procedure depends upon the viability of the fresh cells, which can only be stored for a month or two after any necessary processing.