Preservation and sterilization methods of the meniscal allografts: literature review

Abstract

Nowadays, there are four types of meniscal allografts known: fresh, cryopreserved, deep-frozen and lyophilized ones but only two of them are widely used in clinical practice. Use of different types of meniscal allografts still remains controversial due to preparation method, their biomechanical properties as well as cost which is connected with processing and storage. The main aim of this review is to present the current status of knowledge concerning meniscal allograft preservation and sterilization, especially the advantages and disadvantages of each method. Authors wanted to show a broad spectrum of methods used and conceptions presented by other authors. The second aim is to gather available information about meniscal preservation and sterilization methods in one paper. Deep-frozen and cryopreserved meniscal allografts are the most frequently used ones in the clinical practice. The use of fresh grafts stays controversial but also has many followers. Lyophilized grafts in turn are not applied at present due to some serious drawbacks including reduction of tensile strength, poor rehydration, graft shrinkage and post-transplantation joint effusion as well as increased risk of meniscal size reduction. An application of sterilizing agents make the meniscal allograft free from the bacteria and viruses, but also it may cause serious structure changes. Therefore, choosing just one ideal method of meniscal allograft preservation and sterilization is complicated and should be based on broad knowledge and experience of surgeon performing the transplantation.

Comparison of High‐Hydrostatic‐Pressure Decellularized Versus Freeze‐Thawed Porcine Menisci

“…For a severely damaged and/or defective meniscus, the present gold standard treatment is meniscus allograft transplantation . Four types of menisci are used as meniscal allografts: fresh, cryopreserved, lyophilized, and freeze‐thawed (fresh‐frozen), with the freeze‐thawed meniscus being the most widely used in clinical practice . However, the use of freeze‐thawed menisci has several issues, including disease transmission and immune rejection …”

“…4 Four types of menisci are used as meniscal allografts: fresh, cryopreserved, lyophilized, and freeze-thawed (fresh-frozen), with the freeze-thawed meniscus being the most widely used in clinical practice. 5 However, the use of freezethawed menisci has several issues, including disease transmission 6,7 and immune rejection. [8][9][10] One strategy for overcoming immune rejection is to decellularize the meniscus, which removes the donor's cells while preserving the tissue structure.…”

X-ray microtomography-based measurements of meniscal allografts

“…The study was designed to focus on meniscal allografts potentially intended for transplantation. Usually, when menisci are prepared for transplantation, they are packaged in plastic bags consisting of polyethylene terephthalate/polyethylene and then sterilized using gamma-irradiation [17]. Therefore, removing the plastic foil was not recommended despite the artifacts caused by packaging.…”

Radiation sterilization of tissue allografts: A review

“…It is a suitable method for sterilization of heat sensitive medical products and tissue allografts. Ethylene oxide is a chemical sterilization method which provides both bactericidal and virucidal effects at appropriate concentrations [32] . Ethylene oxide is applied in a gaseous state in mixture with inert diluents such as CO2 [25] .…”

“…The packaging polymer should also not react with the chemical components of tissues during the sterilization process [25] . The efficacy of gamma irradiation is significantly higher when treated in the liquid, hydrated state as compared to tissues in the frozen or freeze-dried state [32,46] . IAEA has actively supported radiation technology for sterilization purposes.…”