In the _impacted variety_, the shortening seldom exceeds one inch; the eversion is less marked; there is some power of voluntary movement; and crepitus is absent. The broadening of the trochanteric region is greater, and the great trochanter is approximated to the acetabulum.
_Prognosis._--The risks to life in the aged are similar to those of intra-capsular fracture. In youths and healthy adults the chief danger is that the limb may be shortened and its function thereby impaired.
As the periosteum and retinacular ligaments which transmit the blood vessels to the proximal fragments are intact, bony union is the rule. There is always, however, considerable thickening in the region of the trochanter due to displaced fragments and callus, and in a certain number of cases, even with the greatest care in treatment, there is a varying degree of shortening and eversion of the limb. In cases in which the distal fragment lies in front of the proximal there is permanent inversion.
_Treatment._--As this fracture usually occurs in robust patients, there is no danger from prolonged confinement to bed; and as union without deformity can be attained in no other way, this is always advisable. When the shortening and eversion are excessive, they should be completely corrected under anæsthesia before the retentive apparatus is applied, any impaction that exists being undone. When the deformity resulting from impaction is slight, however, it is best to leave it, as it facilitates speedy and firm union.
Extension is obtained by the same appliances as are used in fracture of the shaft, and the limb should be kept in the abducted position.
Fracture of the #greater trochanter# occurring apart from fracture of the neck usually results from direct violence, but may be due to muscular action. The trochanter is displaced by the gluteal muscles, causing broadening of the lateral aspect of the hip. In young persons the _epiphysis_ of the great trochanter may be separated, but this is rare. The treatment consists in retaining the fragments in position by keeping the limb abducted between sand-bags, or by pegs driven in through the skin.
#Fracture immediately below the lesser trochanter# may be produced by direct or by indirect violence, and the displacement depends largely on whether the line of fracture is transverse or oblique. The proximal fragment is kept tilted forward, rotated laterally, and abducted by the ilio-psoas muscle and the lateral rotators inserted in the region of the great trochanter. The lower fragment passes upward, and is rotated laterally by the weight of the limb; the displacement is aggravated by the contraction of the flexor and adductor muscles. The tilting of the proximal fragment may be increased by the displaced distal fragment pushing it forward.