Osteochondral grafts - Autograft or allograft?

OATS and mosaicplasty are properly called 'osteochondral grafts'. The word 'osteochondral' means that the grafts contain both bone and cartilage.

This table, which compares the various options for cartilage repair, allows you to compare 'OATS' and 'Osteochondral Allografts Resurfacing'. The OATS procedure is an 'osteochondral autograft' which means that the round osteochondral graft is harvested from the patient himself (or herself), while an 'osteochondral allograft' means the donor material is harvested from a cadaver. 

By using allografts there is no harvesting of healthy cartilage from the patient, so the problem of 'harvest site' problems ('morbidity') goes away. The allografts usually take well, too, as cartilage has no blood vessels or nerves to worry about, and the cartilage grafts are not so readily rejected. There is, of course, always a risk as with any fresh transplant that diseases might be transmitted with the grafts.

Allografts used to be restricted to special centres but are becoming more widely used. As they are transplants from a dead donor, however, and the grafts need also to be fresh, there is always the problem of availability. They are of greatest value in traumatic accidents where the knee is so damaged that harvesting the graft from the patient himself (herself) is not feasible. They are also valuable when an OATS or mosaicplasty has failed and there is nowhere else on the patient's knee to harvest further graft material.