ck
had been marked, and was probably to some extent dependent on
disturbance of the general nutrition of the tissues of the affected
limb. Beyond this, however, it was in many cases a direct result of the
degree of comminution and displacement of the fragments, which
necessitated the formation of a large amount of provisional callus, and
time for the proper consolidation and contraction of the same. In many
cases a large ball-like mass of callus surrounding the fragments was
developed, into which the actual ends of the broken bone only dipped,
and hence union was weak and insecure. As to those cases in which the
wounds closed by primary union, we must bear in mind in this relation
the tardy union often observed in civil practice, when the irritation of
suppuration and consequent inflammation are absent.

Another peculiarity of a similar nature was the occasional late necrosis
of fragments; the wounds apparently healed well, only to break down
weeks or months later for the discharge of a sequestrum. Such cases were
quite distinct from those in which primary suppuration had occurred. I
saw one or two instances in fractures of the humerus, the trouble
arising with commencing use of the limb, and I suppose that fragments
which suffered death at the time of the injury had been enclosed, and
only caused irritation as foreign bodies when the muscles again came
into action. In the absence both of evident necrosis and suppuration,
however, in some cases the exit portion of the track in the soft parts
was extremely slow in healing. Although no discharge beyond a small
quantity of blood-tinged serum escaped, the wounds remained open for
many weeks, even when the fracture consolidated well. I ascribed this to
slow separation of aseptic sloughs, a point which has already been
mentioned under the heading of wounds in general.

Superabundance of callus, as far as I had an opportunity of judging,
comparatively seldom gave rise to permanent mechanical trouble. This was
no doubt due to the infrequency of extension of the comminuted fractures
beyond the junction of diaphysis and epiphysis.

Lastly, with regard to suppuration, only a small proportion of the
fractures, accompanied by the presence of large wounds, escaped
infection. When infection did occur, the results offered some special
features dependent on the small relative amount of damage to the soft
tissues, compared with that suffered by the bone. In an ordinary
compound fractu