Electron microscopic study on the effects of different preservation methods for meniscal cartilage.

OBJECTIVES: The study was conducted to evaluate different methods for preservation of meniscal cartilage. During the last decade, the use of allografts containing cartilage in various forms, such as: small osteochondral grafts, osteoarticular grafts, or whole joints, has gained popularity. Meniscal allografts in particular, can be used in cases of post-menisectomy syndrome, or in uni-compartmental osteoarthritis of the knee. The preservation methods used for the cartilaginous components of allografts would appear to influence the success rates, which vary between 30% and 85% according to different reports. Some of the methods of preservation currently in use include: deep-freezing in liquid nitrogen, freezing to -80 degrees C, gamma irradiation, and immersion in ethylene oxide. METHODS: In an attempt to find the best technique for cartilage preservation (in terms of preserving the ultra-structural properties prior to implantation), bovine meniscal cartilage was examined after preservation by: a) freezing to-80 degrees C; b) exposure to 2.5 Mrad gamma irradiation; or c) a combination of both. RESULTS: Electron microscopic studies were performed, with fresh menisci serving as controls. Our tests demonstrated that in all techniques, severe cellular damage was caused, whereas the collagen network retained its properties. CONCLUSION: The optimal method for the preservation of cartilage remains to be established.