1. The old method in which the limb was lopped off by one sweep, all the tissues being divided at the same level, might be called the true circular. This, however, was soon improved—
A. By Cheselden and Petit, who invented the double circular incision, in which first the skin and fat were cut and retracted, and then the muscle and bone were divided as high as exposed.
B. By Louis, who improved this by making the first incision include the muscles also, the bone alone being divided at the higher level.
C. By Mynors of Birmingham, who dissected the skin back like the sleeve of a coat, and thus gained more covering.
D. Then comes the great improvement of Alanson, who first cut through skin and fat, and allowing them to retract, next exposed the bone still further up by cutting the muscles obliquely so as to leave the cut end of the bone in the apex of a conical cavity.
E. An easier mode, fulfilling the same indications, is found in the triple incision of Benjamin Bell of Edinburgh, who in 1792 taught that first the skin and fat should be divided and retracted, next the muscles, and lastly the bone.
F. A slight improvement on E, made by Hey of Leeds, who advised that the posterior muscles of the limb should be divided at a lower level than the anterior, to compensate for their greater range of contraction.
2. In the progress of the flap operation fewer stages can be defined. Made by cutting from within outwards, after transfixion of the limb, the flaps varied in shape, size, position, and numbers, from the single posterior one of Verduyn of Amsterdam, to the two equal lateral ones of Vermale, and the equal anterior and posterior ones of the Edinburgh school.
Then came the battle of the schools: flap or circular.
Flap.—Speedy, easy, and less painful; apt to retract, and that unequally.