84. Whatever may be the mode and place of the fracture, its diagnosis
presents difficulties which experience and habit may doubtless
overcome, but which too frequently puzzle and embarrass the most
enlightened practitioner. Let us endeavour to diminish them somewhat,
by tracing, in their order of succession, the symptoms which
characterize the accident.
85. At the time of the fall, a sharp pain is felt; sometimes a report
is plainly heard; a sudden inability to move the limb occurs; the
patient cannot rise, a circumstance, however, which does not always
take place. A case is recorded in the fourth volume of the Memoirs of
the Academy of Surgery, where the patient walked home after the fall,
and even rose up on the following day. Some examples of a similar
nature fell under the notice of Desault, one of which he has recorded.
The interlocking of the two fragments formerly mentioned (83), may
serve to explain this fact, which is, however, in general, very rare.
86. A shortening almost always occurs in the broken limb, but this is
more or less perceptible, according as the extremity of the fragments
is retained by the capsule, or as, the division being without the
cavity, no resistance is made to their displacement. The muscular
action, drawing the lower fragment upwards, and the weight of the
trunk, pushing the pelvis and the superior fragment downwards, furnish
here, as in fractures of the body of the bone, the two-fold cause of
this shortening. I will not repeat what has been already said on this
subject (10 ... 14); I will only observe, that, in the present case,
the influence of the muscles is even more considerable, because, the
lower fragment being much longer, is of course attached to a greater
mass of muscular fibres. A slight effort is sufficient, in general,
to remove this shortening, which, however, soon returns, when the
effort ceases. This circumstance Goursault and Sabatier have observed,
not to occur in certain cases, till some time after the accident. A
tumefaction appears in the anterior and upper part of the thigh, almost
always proportioned to its shortening, of which it appears to be the
effect.
87. The projection of the great trochanter is almost entirely removed.
That protuberance, being directed upward and backward, is approximated
to the spine of the ilium. But if it be pushed in the opposite
direction, it readily yields, and then, returning to its proper level,
allows the patient to move the thigh.
88. The knee is a little bent. A severe pain always accompanies the
motions of abduction, when they are communicated to the limb. If, while
the hand is applied to the great trochanter, the limb be made to rotate
on its axis, this bony protuberance is perceived to turn on itself as
on a pivot, instead of describing, as it does in its natural state, the
arch of a circle, of which the neck of the os femoris is the radius.
This sign, which was first observed by Desault, is very perceptible,
when the fracture is at the root of the neck, less, when it is in
the middle, and very little, when it exists towards the head of the
bone; these are circumstances, the cause of which it is unnecessary to
unfold. In rotatory motions, the lower fragment, rubbing against the
upper one, produces a distinct crepitation, a phenomenon which does not
however always occur.
89. The point of the foot is usually turned outwards; a position
which Sabatier, Bruninghausen, and most other practitioners regard as
a necessary effect of the fracture, although Ambrose Pare and Petit
have borne witness that it does not always exist. Two cases, reported
on this subject by celebrated surgeons, have been thought unfounded
by Louis, who has attributed them either to an error in language, or
a mistake of the transcriber. But the practice of Desault has fully
confirmed their possibility. The first patient whom he had under his
care, at the hospital of Charity, after he was appointed surgeon in
chief, laboured under a fracture which presented this phenomenon. Many
other examples occurred to him afterwards, and he believed it might
be laid down as an established principle, that, in fractures of the
neck of the os femoris, the direction of the foot outwards is to that
inwards as 8 to 2.
90. The common opinion is, that this direction outwards is to be
attributed to the muscles that perform rotation. But, were that
the case, 1st, it is evident that it would always exist: 2dly, all
the muscles running from the pelvis towards the trochanter, except
the quadratus, are in a state of relaxation, in consequence of the
approximation of the os femoris to their points of insertion: 3dly,
muscles in a state of contraction would not allow the point of the foot
to be drawn so easily inwards. Is it not more probable, that the weight
of the part draws it in the direction in which it is usually found.
91. From the foregoing considerations, it follows, that none of the
signs of a fracture of the neck of the os femoris, is exclusively
characteristic, that the whole of them, taken separately, would be
insufficient, and that it is their assemblage alone which can throw on
the diagnosis that light which is oftentimes wanting to it, even in
the view of able practitioners. But after all, in the present case, as
in every other one, should any doubt exist, it is right to take the
safe side, and apply the apparatus, which is indeed useless but not
dangerous if the disease does not exist, but indispensably necessary if
it does.
§ XV.