This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
Impaction of the other fragment by the neck of the bone is not rare, and firm union may occur. If the fracture is close to the head, the neck is impacted into and penetrates the head, but if the fracture is close to the trochanters the neck penetrates the trochanters, frequently splitting them.
In old people the bone is weakened by atrophy and the neck is often fractured by indirect violence, as by twisting, etc. Then the fracture is a high one; if, however, the fracture is by direct violence, as by falling and striking the hip, then the fracture is apt to be close to the trochanters and the prognosis better. Hence the importance of ascertaining the history of the injury. Fracture also occurs in young adults and children, usually from direct injury.
The injury is treated (1) by widely abducting the thigh, which elevates the lower fragment to the upper; (2) by adhesive plaster extension combined with lateral weight traction pulling the upper part of the thigh out, which renders tense the capsule and so brings the fractured surfaces in apposition; or (3) by Thomas's splint which is of metal and extends from the level of the axilla to below the knee; this ensures immobility and facilitates handling of the patient.
This is almost always the result of a direct injury or blow on the hip. Impaction is almost the rule, the upper fragment being driven into the lower. Shortening and other symptoms are usually not so marked as in the other fractures and almost any method of treatment is followed by good results.
These may be in the upper, middle, or lower third. They all have a common displacement. The upper fragment is displaced forward and outward and the lower fragment backward and usually inward. The foot is usually everted.
The displacement of the upper fragment forward and outward is usually marked. It is caused by the iliacus, psoas, and pectineus pulling it forward and rotating it out and the gluteus minimus and medius abducting it. The lower fragment is pulled in by the adductors and posteriorly by the gastrocnemius and plantaris (Fig. 540). This is a troublesome fracture and is treated either by a double inclined plane or anterior wire splint with the limb in a flexed and abducted position or else the fragments are to be wired or pinned together.
The displacement is the same as in the upper third but to a less extent. It is usually treated by adhesive plaster extension with the leg abducted.
This is a particularly dangerous fracture because the lower fragment is drawn backward by the gastrocnemius and plantaris, and the popliteal vessels and internal popliteal nerve may either be wounded primarily or stretched over its sharp upper edge (Fig. 541). The artery lying deepest is the most liable to injury, then the vein, and finally the nerve. Gangrene necessitating amputation has occurred. Of course in attempting to replace the fragments the knee should be flexed to relax the gastrocnemius and plantaris. Some cases can be treated by ordinary extension with the knee straight, others with the knee flexed, but others may require operation and fixing by pins or wiring. William Bryant divided the tendo Achillis for the purpose of relaxing the pull of the gastrocnemius.
Fig. 541. - Supracondylar fracture of the femur. The lower fragment is seen to be drawn back into the popliteal space by the gastrocnemius and plantaris. The vessels are stretched over the sharp edge of the lower fragment.