Cryopreservation does not alter the ultrastructure of the meniscus

Abstract

Fresh frozen menisci have recently been shown to have an altered meniscal ultrastructure. The cause might be a deterioration of its permeability due to collagen net disarray. The purpose of this study was to evaluate the cryopreserved meniscus in terms of ultrastructure and cellularity. Ten fresh human lateral menisci were harvested. Collagen architecture was evaluated with transmission electron microscopy. The Collagen Meniscal Architecture scoring system was used to assess the degree of meniscal disarray. Cell population, was also evaluated. The fibril collagen diameters of those menisci which had been previously cryopreserved showed an average size in the longitudinal section of 12.6 +/- 1.3 nm, whereas it was 13.4 +/- 2.2 nm in the menisci used as controls (n.s.). In the transverse section, the cryopreserved menisci averaged 15.5 +/- 2.4 and 16.7 +/- 3.5 nm in the controls (n.s.). The study group scored 4.8 points +/- 1.7, whereas the control group did so at 4.1 +/- 1.3 (n.s.). The percentage of cell survival after the cryopreservation ranged from 4 to 54. The fibril diameters and degree of disarray showed a similar distribution in both groups. The results suggest that meniscal cryopreservation does not alter the meniscal ultrastructure. Therefore, an allograft stored in that way would not alter its biomechanical properties, although its cellular viability is highly unpredictable.

Allograft Meniscus Transplantation: A Current Review

“…Therefore, an allograft stored in that way would not have altered biomechanical properties even though its cellular viability is highly unpredictable. 18 Fresh and viable: Fresh menisci, harvested from multiorganic donors, are not a common alternative. The grafts must be used within a short period of time so as to maintain viability and there are concerns relative to the transmission of infectious diseases.…”

Preservation and sterilization methods of the meniscal allografts: literature review

“…Dimethyl sulfoxide and glycerol protect cells against the formation of intracellular ice crystals. According to recent data, the percentage of cell survival after cryopreservation has been established between 4 and 54 % (Gelber et al 2009). Other data indicate a percentage of viable cells after thawing between 10 and 40 % (Milton et al 1990; Jackson and Simon 1992).…”

“…There are two very important issues to be considered before the transplantation: whether the graft has to contain viable, metabolizing cells that are able to divide, and—on the other hand—whether it has to keep its scaffold architecture to function rightly (Gelber et al 2009). Apart from these questions, surgeons performing meniscal transplantation should be aware of the advantages and disadvantages of meniscal allograft preservation and sterilization methods, because the way of the allograft pre-transplantation preparation of the allograft can affect its physical properties and strength.…”

Meniscal Allograft Transplantation: Where are we Standing?

“…Jackson et al demonstrated that within 4 weeks, the donor cells of fresh grafts are replaced by host cells in goats [49]. Gelber et al demonstrated that cryopreservation did not elicit a significant modification in the collagen network by means of degree of disarray and fibril diameter, although the loss of viable cells was unpredictable [50]. In fact, it has been demonstrated that cryopreservation increases cell apoptosis in human menisci [51].…”