Major advances have been made in the repair of knee cartilage. Commercially available full-thickness cartilage tissue called osteochondral allografts have been in use for about the last 10 years. Allograft refers to tissue donated to a tissue bank.
Researchers are exploring storage times for the donated tissue. We know that grafts used in the first 14 days of harvest have good-to-excellent results. In this study, the results of grafts older than 14 days are reviewed.
Nineteen patients with damage to the cartilage and first layer of bone on the femur (thighbone) were included. All were treated with osteochondral allograft and followed for at least two years.
Before and after measurements were taken of function. X-rays and special cartilage-sensitive MRIs were taken before and after to document change. MRIs showed that in general, the thickness of the allograft stayed the same. None of the grafts shifted or moved out of place. The grafts filled in most of the defects.
The longer graft storage times seemed to produce better results compared with fresh grafts. There was less swelling around the graft and better shaping and fill-in by the graft material. The scientists weren’t sure how to explain these results.
The authors comment that there weren’t enough patients in the study to answer some questions. Future larger studies should look at the effects of age and body size on results. Results based on the size and type of lesion should also be assessed. Long-term studies are needed to see if the tissue breaks down over time.