If the condition is not recognised and treated, it is liable to be followed by the development of coxa vara (Royal Whitman) (Fig. 65).
[Illustration: FIG. 65.--Coxa Vara following Fracture of Neck of Femur in a child.]
#Fracture through the Base of the Neck.#--This fracture is usually produced by a fall on the great trochanter, although it is occasionally due to a fall on the feet or knees.
[Illustration: FIG. 66.--Non-impacted Fracture through Base of Neck.]
Although often spoken of as "extra-capsular," the line of fracture is generally partly within and partly without the capsule. The fracture usually lies close to the junction of the neck with the shaft, and in the great majority of cases is accompanied by breaking of one or both trochanters. This is due to the neck being driven as a wedge into the trochanters, splitting them up. When the fragments remain interlocked, the fracture is of the _impacted_ variety (Fig. 67).
[Illustration: FIG. 67.--Fracture through Base of Neck of Femur with Impaction into the Trochanters.]
_Clinical Features._--Although this fracture is commonly met with in strong adults, it may occur in the aged.
The lateral aspect of the hip shows marks of bruising, and there is severe pain and a considerable degree of shock. The limb lies helpless; there is generally marked eversion, with shortening, which, in _non-impacted_ cases, may amount to 1-1/2 or 2 inches, and is evident immediately after the accident; it is due to the distal fragment being drawn up by the muscles inserted into the great trochanter and upper end of the shaft. In a limited number of cases the distal fragment lies in front of the proximal, and there is inversion of the limb.
[Illustration: FIG. 68.--Non-impacted Fracture through Base of Neck. Union has occurred with diminution of angle of neck--Coxa Vara.]
On applying the various tests, the great trochanter is found to be displaced upwards, there is some antero-posterior broadening of the trochanteric region, and the ilio-tibial band is relaxed. On pressing the fingers into the lateral part of Scarpa's triangle, a mass consisting of the bony fragments may be felt, and is tender on pressure. Unnatural mobility with crepitus may be elicited.