Outline of amputation of fingers, with their metacarpals. (Modified by Matas from Mignon.)
In the lower part of the forearm the flap method furnishes a serviceable stump. As the elbow is approached the circular or elliptical methods are preferable, as illustrated in [Fig. 690].
The Elbow.
—With elbow disarticulations caution should be observed to have flaps of sufficient length. The joint is opened more readily from its radial side. The integument of the back of the elbow region lies closely upon the bone, is thin, and retracts but slightly. Anteriorly there is more muscular covering and consequently a tendency to retraction. Therefore the anterior flap should be made longer than might otherwise seem to be required. Here the ideal scar will be behind the end of the humerus, but it is difficult to obtain because of the tendency to drag it around beneath the end of the bone. An elliptical incision, directed obliquely downward and forward, is the easiest method and furnishes the best stump. The lower end of the posterior part of the flap should be at a distance below the articulation, at least equal to the transverse diameter of the joint itself, i. e., in an adult nearly one hand-breadth from the line of the joint to the point of dissection. (Matas.) ([Fig. 690].)
The Arm.
—The arm furnishes that nearly cylindrical outline best adapted for circular amputations. Here, as at the elbow, the greatest retraction is on the flexor side. With the arm should be saved all that is possible even up to its upper extremity.
Remembering the greater tendency of the flexors to contraction the truly circular method should be modified to a somewhat elliptical incision, in order to compensate for this difficulty, while an external liberating incision is often of assistance. Abrupt transverse division of the muscle down to the bone should be made after the oblique incision of the skin.
Fig. 689
