The injury was caused by an 8 mm. bullet, which entered base foremost and lodged in the calf. The fracture is really an incomplete stellate form, two well-marked transverse fissures extending from the point struck. The position of the bullet suggests its entry into the limb base foremost, and as it is retained low velocity may be assumed.
This fracture was produced by a bullet travelling at a high rate of velocity, which struck the posterior surface of the tibia, and caused a grooving, accompanied by a horizontal fissure through the whole thickness of the bone; later it struck the fibula more directly, and produced an ordinary comminuted fracture two inches above the malleolus. Perforations of the shaft were far more common than in the case of the femur, and I saw them in every part of the length of the bone (plate XXI.). Fig. 57 illustrates a form of peculiar interest as showing the gradual transition of the tunnel to the groove, and also as bringing fractures of the long bones into line with such fractures of the flat bones of the skull as are depicted in fig. 68.
Fig. 57.
(42) Perforation of lower third of Tibia, showing lifting and fissuring of the compact roof of the tunnel. Compare with fig. 68, p. 259, of a fracture of the cranial vault.
Fractures of the fibula offered no special features of importance. Any form might occur. The plate No. XXIII. is of interest as showing a spurious form of perforation, and also the primary form of displacement of the fragments in stellate fractures. It was produced by a reversed ricochet, but undeformed, bullet, still seen in position in the skiagram; the bullet only possessed sufficient force to perforate the bone, and then appears to have turned on its transverse axis. The following plate, No. XXIV., is inserted to show the depth at which the bullet lay, and its distance from the surface of the tibia, which appears in the first plate to be nil. It is also of interest as showing the ease with which a false impression may be obtained from a single picture, as, beyond a spot of transparency, no obvious injury to the fibula, and certainly no displacement, is discernible.
(41a) This skiagram is inserted to show the depth at which the bullet lay from the surface. It is also interesting to note the insignificance of the fracture of the fibula from this aspect. Without the second skiagram the injury might have passed for a simple perforation or a transverse fracture.
Fractures of the bones of the leg possessed an unenviable degree of importance. First, on account of the very severe injuries to the soft parts that often accompanied them, without an apparently correspondingly serious damage to the bone. Secondly, on account of the frequency with which the vessels were implicated in these injuries to the soft parts, either by the bullet or bone fragments. Beyond this, fracture of either articular end of the tibia was certainly more frequently followed by troublesome joint complications than occurred in the case of any other bone.