Methods and devices to process harvested skin tissue and to immediately reintroduce the ground tissue into the patient to repair a tissue defect are disclosed. A hand-held portable tissue grinder comprising a housing and a grinding element are disclosed. The tissue grinder is used for grinding skin and subcutaneous tissue and includes a sterile polymer housing having a first opening adapted to receive the skin and subcutaneous tissue. The tissue grinder also includes a sterile grinding element disposed substantially within the housing. The grinding element includes a plurality of cutting surfaces adapted to operably engage with the housing to provide ground tissue and further includes a handle mechanism coupled to the grinding element to move the grinding element with respect to the housing to grind the skin and subcutaneous tissue, wherein the ground tissue can be removed from the housing.