The distinction between lacerations and cuts in ligaments and tendons

In contrast to skin wounds the characteristic forensic features of lesions of ligaments and tendons have rarely been investigated. However, in a suspected homicide the question became crucial whether an isolated discontinuity of the posterior atlanto-occipital membrane was caused by a rupture mechanism or by a cut. In order to reevaluate the associated criteria experimental lesions were made in ligaments and tendons and examined histologically. From these experiments the following criteria could be established: Lacerations exhibit complete destruction of the tissue texture with microruptures and splitting of fibres in the adjacent region. Such would edges have an irregular structure and fibres near the rupture site exhibit variable thicknesses due to traction. Incisions exhibit smooth wound edges with no disturbance of the tissue texture. The thickness of fibres near the rupture site is regular. These results were obtained by light microscopical examination and confirmed using electron microscopy. Under controlled experimental conditions the forces necessary to rupture tendons with a diameter of 1 mm varied between 50-70 Newton (N). In the suspected homicide, the lesion of the posterior atlanto-occipital membrane was examined visually and histologically and was compared with the experimentally established criteria. Based on these criteria the lesion could be identified as an incision which had probably been caused accidentally while severing the medulla during the first autopsy and was therefore not connected with the cause of death.