6. Elliptical or oval incision with long projection on flexor side to compensate for greater retraction of skin and muscles on flexor (ventral side); the longer end of the oval may be advantageously reversed, the long end on the exterior side, when the tissues on the flexor side are injured. Usually, a slightly elliptical circular, with two lateral liberating incisions, cut squarely to the bone with all the soft parts, including the periosteum, is the preferred method in this region.
7. Antero-posterior flap incision for amputation at lower third of forearm; tendinous region.
8. Oval or elliptical incision in typical amputation of the hand (radio-carpal disarticulation).
Fig. 690
Lines of amputation in lower third of forearm, of elbow, and lower third of arm. (Modified from Mignon.)
Circulation being thus controlled, a modified circular operation may be made or a long external and superior flap cut, matching it with another one dissected from the axillary aspect. In the former case the circular incision is made on a level a little below the anatomical axillary border. Then a cuff of skin being raised while the arm is held in adduction, all the soft parts are divided to the bone and separated from it. Now a liberating incision may be made from the anterior border of the acromion to the coracoid process, then over to the deltoid groove, and along it to the first circular incision. Through this all the soft tissues surrounding the glenoid margin are separated, and then the bone is enucleated by opening the capsular ligament, reserving perhaps the detachment of the group of scapular tendons until the last. If one have any fear as to the efficiency of his hemostatic precautions he may secure the axillary vessels so soon as they are divided and then proceed with the disarticulation as above. In some cases it may be preferable to cut a wide flap from the deltoid region, preserving that muscle or not as may be desired, and, after having thus exposed the joint, make the disarticulation, separating the head of the bone sufficiently to allow the passage of an amputating knife behind it and down along the shaft to a distance sufficient to justify turning it abruptly and toward the surface, and then cutting out the axillary flap. The attempt should be to cut all the vessels at right angles rather than obliquely.
[Plates LVII] and [LVIII], prepared by Professor Matas, afford a synoptic view of the more useful lines of skin incision in the principal amputations of the arm and shoulder.