mass of
callus, and the fracture united, with considerable shortening.]
Plate XIV. offers a good contrast; the fracture here presents a typical
stellate form, and a good result without shortening was readily
obtained. I assume that the difference in character of these two
fractures depended mainly on the rate of velocity with which the bullet
was travelling, since it passed fairly directly across the limb in each.
I think it is clear, however, that the bullet struck the femur rather
nearer the centre of the width of the shaft and therefore more directly,
in the more severe injury.
This brings me to the question of explosive exit wounds in the thigh. In
spite of the great tendency to comminution of the shaft, these were rare
in a severe form. This depended simply on the depth and thickness of the
coverings of the bone, and, as already mentioned, although the skin
openings were often comparatively small, a large cavity or area of
destroyed soft tissues may be contained within the limb. I do not think
I ever saw an exit wound in the thigh exceeding 1-1/2 inch in diameter.
The oblique fracture illustrated by plate XVI. has been already referred
to, and the influence of the weight and movement of the trunk on its
production has been considered.
Plate XV. illustrates an obliquely comminuted fracture of another
character. The bullet has here been stripped of its mantle, which has
undergone fragmentation, but the leaden core is little altered in shape.
This is of much interest, since it shows that the bullet struck the bone
by its side. The effect of such lateral impact on the part of the
projectile is well shown: there is great bone comminution of a less
regular character than usual, and the bullet is retained. Retention in
this case was probably not a result of low velocity of flight, but of
the increased resistance offered by the broad area of bone struck, and
the check exerted on the axial rotation of the bullet by the lateral
contact.
[Illustration: PLATE XIII.
Engraved and Printed by Bale and Danielsson, Ltd.
(31_a_) THE FRACTURE SHOWN IN PLATE XII., SIX MONTHS AFTER RECEPTION OF
THE INJURY
The amount of callus furnished around the loose fragments is very
striking.
The upper end of the bone is shown to have been divided into at least
two fragments, hence one of the difficulties of maintaining the ends in
apposition. The stoppage of the fissuring short of the epiphysis is
characteristic.]
Slighter
|