Effects of different temperatures and periods of preservation in menisci cellularity in rabbits

Abstract

Purpose: Quantify the progressive decrease of the cellular viability of rabbit meniscus preserved for transplants over a 30 day period at different freezing temperatures.

Methods: 180 menisci were removed from 45 rabbits. Menisci were frozen from 2 to 30 days at -7.2 degrees Celsius -21.4 degrees Celsius and -73 degrees Celsius. Four menisci from each temperature were thawed every two days and the number of present cells was quantified.

Results: On the 14th freezing day at -7.2 degrees Celsius, there were 92.38% mean viable cells. However, as from the 16th day, there has been a significant 12% decrease (p = 0.001), as compared to 14th day mean. Mean cell viability at -21.4 degrees Celsius and -73 degrees Celsius, until the 16th day was statistically similar. As from the 18th day at -21.4 degrees Celsius, there has been significant cell count decrease (p < 0.001), especially from the 28th (54.5%) to the 30th (30%) freezing day. The number of viable cells at -73 degrees Celsius has shown insignificant 2.3% decrease (p = 1.000) from the 28th (40.2%) to the 30th (37.9%) day.

Conclusion: The amount of viable meniscus cells is similar up to the 14th day of preservation, under any of the used temperatures. However, from the 14th day to the 30th day, the amount of viable cells is smaller in lower temperatures.