The anatomy of the human skeleton / by J. Ernest Frazer.

  • Frazer, John Ernest Sullivan, 1870-1946.
Date:
1920
Catalogue details

Licence: In copyright

Credit: The anatomy of the human skeleton / by J. Ernest Frazer. Source: Wellcome Collection.

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    largely brought about by the extent of development of the strong ridge on the lower and front part of the neck, that acts as a bracket in strengthening the curve. The neck should be looked on as the upper part of the shaft (Fig. 116) incurved, with the muscular trochanters applied to it, but not interfering with the lines of the walls of the shaft : intersecting arcades of cancellous lamellae spring from these walls and support the articular surface. fibres—below and behind, below and in front, and above, internal to the front part of the great trochanter. The last-mentioned is a broad band that~extends in towards the head for some distance beyond the epiphysial line of the trochanter, which (Fig. 117) encroaches here considerably on the upper aspect of the neck. The posterior aspect is usually smooth, because there are here no true transverse fibres in the capsule to gain an insertion on the bone : a few marginal fibres of the circular group are the only ones that have any insertion into the femur, and the synovial membrane is reflected from the bone to the deep surface of the circular zone directly. The line of reflection (Fig. 117) is about half-way up the neck, continued up from the turned-up lower end of the anterior intertro¬ chanteric line. The Obturator externus is closely applied to the lower and back part of the neck, passing to the digital fossa, and the pressure of this muscle moulds the shape of the bone slightly : an indefinite suggestion of an oblique line (Fig. 118) directed outwards and upwards shows the upper limit of the surface affected by this muscle. Below this line the capsule is in relation with the Obturator Fig. 116.—1, Diagram of femur at birth; cartilage is dotted. Upper end shows cartilage to a lower level behind, because the small trochanter is continuous here with great. Observe the short neck. 2, A later condition, in which the shaft (thick lines) has grown in length, carrying the head away from the trochanters and so lengthening the neck. The lower part of the head is formed at first by this shaft, but this is afterwards hidden by epiphysial growth. Trochanters remain as masses applied to the wall of the shaft. 3, A scheme of a section through the small trochanter, showing it applied to the shaft; the part of the wall which carries it is thick and forms the calcar femorale (see Fig. 125). externus, and above it is covered by the Obturator internus and Gemelli, so that the Quadratus femoris has no direct relation with the capsule at all. The existence of a long neck is a necessity in a bone which, like the femur, has a head received in a deep articular cavity for purpose of security : if such freedom of movement as the femur enjoys is to be obtained, the body of the bone must be carried at some distance from the embedded head. Necks are more vertical in long femora. The front of the neck is ridged in its long axis and shows numerous vascular foramina. These occur owing to the fibrous bands with small accompanying vessels that lie under the synovial membrane : the membrane covers the whole of this face of the bone, extending to the anterior intertrochanteric line. The fibrous bands run from the capsular attachment here towards the head : they are termed retinacula, and there are three main collections of these The Great Trochanter (Fig. 118). The great trochanter is a traction epiphysis formed at the attachment of the gluteal muscles, and pulled as a sort of hood over the base of the neck. The descriptive