Fig. 313
Impacted fractures of necks of femurs.
Signs of fracture of the neck of the femur of special import are history of injury, pain, loss of function, shortening, rotary displacement, usually eversion, crepitus, relaxation of the fascia lata, and disarrangement of the lines of triangulation between the bony prominences of the pelvis and the trochanter. Diagnosis should be attempted with as little manipulation as possible lest impaction be dislodged. The patient should be placed upon a comfortably hard surface. Anesthesia will sometimes afford important aid. It should be ascertained, first, that there had been no previous injury which could produce shortening. If, then, shortening be apparent it is of itself almost a diagnostic sign. Such a limb is practically helpless, and unless the neck be so driven in upon itself as to produce impaction the foot will be usually everted, while the tension of the fascia lata will be relaxed and there will be fulness in Scarpa’s triangle. Absolute inability to use the limb implies fracture without impaction. Should the patient have been able to help himself or work after the injury, impaction may be safely assumed. The parts are exceedingly tender and pain is easily produced. Shortening is to be assumed only after placing the limbs and body in a perfectly symmetrical position (the pelvis being at right angle with the spine), after which the measurement most usually made is from the anterior superior spine to the internal malleolus. Nélaton’s line is the shortest line which can be made to pass around the hip, in one plane, from the anterior superior spine to the tuberosity of the ischium. While the line is curved it should lie in the same plane. Normally this passes just over the great trochanter. If there be real shortening the trochanter should rise above this line to an extent corresponding with the shortening made out by other measurements. Still another method of measurement is to hold a straight edge opposite to the superior spine and perpendicular to the surface upon which the patient is lying; the distance between this edge and the great trochanter should be as much less than the distance found by similar measurement on the other side as the amount of shortening measured by the other methods. This is the easiest way to measure the lines included in Bryant’s iliofemoral triangle. Both are illustrated in [Fig. 314]. Impaction can sometimes be determined by comparing triangles drawn between three points on either side, these points being, respectively, the great trochanters, the anterior spine, and the centre of the pubis, which is common to both. The lower line of the triangle on the injured side should be shorter than on the other, in proportion as the head and the end of the shaft have been driven toward each other.
Fig. 314
Nélaton’s line, dark. Bryant’s iliofemoral triangle, dotted. (Erichsen.)
Crepitus is a sign to be elicited with care and gentleness. Up-and-down movements of the thigh upon the side of the pelvis or gentle rotary movements, combined with circumduction of the knee, will yield it if it is to be easily detected. Every effort of this kind disturbs the injured bone and should be minimized as much as possible. One other sign of considerable value is the fact that if the patient be turned upon his face a fractured femoral neck will permit the leg to be hyperextended to a degree not permitted by the normal condition. In making this test the pelvis should be held firmly; it should be made but once, the intent being to disturb the parts as little as possible.
Diagnosis.
—The diagnosis of fracture is often easy, but in some cases it is accompanied by many difficulties. It would be better to give the patient the benefit of a doubt and treat him for a fracture with rest than to subject him to excessive manipulation. Such an injury is not likely to be mistaken for anything else save a dislocation of the hip, although occasionally separation of the margin of the acetabulum might cause confusion.