Early pathomorphologic characteristics of the wound track caused by fragments

Soft-tissue wounds were inflicted on the upper parts of both hind legs of dogs by fragments which were shot with a smooth-bore testing rifle. Three impact velocities were used: "high" (1,500 m/s, six dogs), "middle" (1,000 m/s, eight dogs) and "low" (700 m/s, seven dogs). Debridement and gross examination were carried out 6 hours after wounding. The main conclusions were as follows: 1) Grossly, most of the wound tracks were blind. The primary wound track in the "high"-velocity group looked like a funnel in shape. The wound cavity close to the entrance had the largest diameter. 2) The severity of the tissue damage depended on the impact velocity. The higher the velocity, the larger were the wound cavities, the more tissues damaged, and the wider was the area of tissue damage around the cavity. 3) Based on the gross, light microscopy (LM), and electron microscopy (EM) observations it was found that one of the predominant characteristics of the tissue damage caused by fragments was the irregularity or unevenness. This was especially true in the case of the "high"-velocity group. The distribution of tissue damage seemed to be "jumping" or "mosaic." This probably resulted from the irregularity of the energy delivery from fragments with high velocity and low mass. 4) The differences in morphologic characteristics between wound tracks caused by bullets and those by fragments are discussed.