The right medial collateral ligament of ninety-four adult, female
rabbits was transected operatively. At three, six, fourteen, or forty weeks
after the operation, the uninjured, contralateral (left) medial collateral
ligaments of seventy-eight of the animals were tested biomechanically and
compared with the left medial collateral ligaments of thirty-three normal
female rabbits. The diameters of the mid-substance collagen fibrils in the
medial collateral ligaments were also measured in the uninjured,
contralateral hindlimbs of four animals at each interval and compared with
the fibril diameters in three normal animals at each of three corresponding
intervals. Subtle but significant differences between the uninjured,
contralateral and the normal medial collateral ligaments with regard to
biomechanical properties of collagen fibril diameters were found at all
time-intervals. These results support the notion of a significant effect on
the contralateral ligament after an injury to the medial collateral
ligament and suggest that contralateral ligaments cannot be considered as a
normal control group even in this relatively benign model of knee
injury.