[Illustration: FIG. 81.--Extension applied by means of ice-tong callipers for Fracture of Femur.] Hodgen's splint, bent nearly to a right angle, may also be employed. A careful watch must be kept on the circulation of the limb during the first few days, lest it be interfered with by the pressure of the apparatus. In a considerable number of cases these means of retaining the fragments in apposition prove ineffectual, and it is necessary to have recourse to operative measures for mechanical fixation. Division of the tendo calcaneus (Achillis) is not to be recommended as a means of combating the backward tilting of the distal fragment. In all cases the retentive apparatus must be worn for about four weeks, after which the limb is flexed over a pillow; but massage and movement should be employed as soon as possible, as persistent stiffness of the knee is one of the most troublesome sequelæ of these injuries. Compound and complicated fractures are dealt with on the general principles governing the treatment of such injuries. Amputation may become necessary should gangrene ensue from injury to the popliteal vessels, or if infective complications threaten the life of the patient. Operative interference may be called for to rectify deformities resulting from mal-union. The #T- or Y-shaped fracture# is, as a rule, produced by direct violence, the force first breaking the bone above the condyles and then causing the proximal fragment to penetrate the distal and split it up into two or more pieces. The fracture implicates the articular surface, and the main fissure is usually through the inter-condylar notch; the lower end of the bone is sometimes severely comminuted. The knee is broadened, and pain and crepitus are readily elicited on moving the condyles upon one another or on pressing them together. On moving the patella transversely, it may be felt to hitch against the edge of one or other of the fragments. The shortening may amount to one or two inches. The treatment is carried out on the same lines as in supra-condylar fracture, but as the joint is implicated there is greater risk of subsequent impairment of its functions.