The influence of the following modes of postmortal storage on tensile strength characteristics and histology of rabbit ligaments were studied: (A) in saline for 5 hours +20°C; (B) in saline for 24 hours +4°C; (C) deep-freezing; (D) in 10 per cent formaldehyde. In each group 8 knees were included. The fresh control material consisted of 14 knees.
The following parameters were employed: (i) the gross shape of the load-elongation curve, (ii) its slope (tan α), (iii) its failure energy, (iv) failure load, (v) elongation at failure, (vi) dips in the recorder's load curve, and (vii) failure site on the bone-ligament-bone preparation.
Standard histological methods were used.
None of the modes of storage proved satisfactory for the preservation of the tensile strength characteristics of the fresh soft connective tissue.
Only storing in formaldehyde (in fact fixing in it) proved satisfactory for histological studies.
These findings are discussed and it is concluded that biomechanical tests on collagenous tissue removed at surgery must be performed with no time lapse.