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behind it, is a hollow, oval pit (fovea capitis femoris) for the attachment of the ligamentum teres. Piercing the floor of this depressionl are seen several foramina
through which vessels pass to supply the head of the bone; the proximal epiphysis thus having a double blood supply, viz., from the neck distally, and through the medium of the ligamentum teres proximally. The circumference of the head forms a lip with a wavy outline, more prominent above and behind than in front.
The head is supported by a stout compressed bar of bone, the collum femoris (neck), which forms with the proximal end of the body an angle of about 125 degrees, and is directed proximally, medially, and a little forwards. Its vertical width exceeds its antero-posterior thickness. Constricted about its middle, it expands medially to support the head, whilst laterally, where it joins the shaft, its vertical diameter is much increased. Anteriorly it is clearly defined from the shaft by a rough ridge which commences above on a prominence, sometimes called the tubercle of the femur, and passes obliquely downwards and medially. This constitutes the upper part of the linea intertrochanterica (intertrochanteric line), and serves for the attachment of the ilio-femoral ligament of the hip-joint. Posteriorly, where the neck unites with the body, there is a full rounded ridge passing from the trochanter major proximally to the trochanter minor distally; this is the crista intertrochan
terica (intertrochanteric crest). A little proximal to the middle of this ridge there is usually a fulness which serves to indicate the proximal limit of attachment of the quadratus femoris muscle, and is called the tubercle for the quadratus.. Laterally the
neck is embedded in the medial surface of the trochanter major, by which, at its upper and dorsal part, it is to some extent overhung. Here is situated the trochanteric fossa, into which the tendon of the obturator externus is inserted. Passing nearly horizontally across the back of the neck there is a faint groove leading into this depression; in this the tendon of the obturator externus muscle lies. Distally the neck becomes confluent with the trochanter minor behind, and is continuous with the medial surface of the body in front. The neck is pierced by many vascular canals, most numerous at the proximal and dorsal part. Some are directed proximally towards the head, whilst others pass in the direction of the trochanter major.
The trochanter major (greater trochanter) is a large quadrangular process which caps the proximal and lateral part of the body, and overhangs the root of the neck above and behind. Its lateral surface, of rounded irregular form, slopes upwards and medially, and is separated from the lateral surface of the body distally by a more or less horizontal ridge. Crossing it obliquely from the posterior superior to the anterior inferior angle is a rough line which serves for the insertion of the
FIG. 239. DORSAL ASPECT OF THE
gluteus medius muscle; both proximal and distal to this the surface of the bone is smoother and is overlain by bursæ. The ventral surface, somewhat oblong in shape, and inclined obliquely from below upwards and medially, is elevated from the general aspect of the body, from which it is separated in front by an oblique line leading upwards and medially to the tubercle at the upper end of the superior part of the intertrochanteric. line. This surface serves for the insertion of the gluteus minimus. The superior border is curved and elevated; into it are inserted the tendons of the obturator internus and gemelli muscles medially and in front, and the piriformis muscle above and behind. The dorsal border is thick and rounded, and forms. the upper part of the intertrochanteric crest. The angle formed by the superior and dorsal borders is sharp and pointed, and forms the tip of the trochanter overhanging the trochanteric fossa, which lies immediately below and medial to its medial surface.
The lesser trochanter (trochanter minor) is an elevated pyramidal process situated at the dorsal side of the medial and proximal part of the body, where that becomes continuous with the distal and dorsal part of the neck. Confluent above with the intertrochanteric crest, it gradually fades away into the dorsal aspect of the body below. The combined tendon of the ilio-psoas is inserted into this process and into the bone immediately below it.
The body (corpus femoris), which is characterised by its great length, is cylindrical in form. As viewed from the front, it is straight or but slightly curved; as seen in profile, it is bent forwards, the curve being most pronounced in its proximal part. The body is thinnest at some little distance proximal to its middle; distal to this it gradually increases in width to support the condyles; its anteroposterior diameter, however, is not much increased distally. Its surfaces are generally smooth and rounded, except behind, where, running longitudinally along the centre of its curved dorsal aspect, there is a rough-lipped ridge, the linea aspera. Most salient towards the middle of the body, the linea aspera consists of a medial lip and a lateral lip, with a narrow intervening rough surface. Proximally, about 2 to 2 inches from the trochanter minor, the linea aspera is formed by the convergence of three lines. Of these the lateral is a rough, somewhat elevated ridge, called the gluteal tuberosity which commences proximally, on the back of the body, lateral to and on a level with the trochanter minor, and becomes continuous distally with the lateral lip of the linea aspera. This serves for the bony insertion of the gluteus maximus, and is occasionally developed into an outstanding process called the trochanter tertius. The medial lip of the linea aspera is confluent proximally with a line which winds round the body proximally and forwards, in front of the trochanter minor, to become continuous with the intertrochanteric line (see p. 240). The whole constitutes what is known as the spiral line, and extends from the anterior part of the trochanter major proximally to the linea aspera distally. Intermediate in position between the spiral line in front and medially, and the gluteal ridge laterally, there is a third line, the pectineal line, which passes distally from the trochanter minor and fades away into the surface between the two lips of the linea aspera. Into this the pectineus muscle is inserted. About the junction of the middle with the distal third of the body the two lips of the linea aspera separate from one another, each passing in the direction of the epicondyle of the corresponding side. The lines so formed are called the medial and lateral epicondylic lines, respectively, and enclose between them a smooth triangular area corresponding to the back of the distal third of the body; this, called the planum popliteum (popliteal surface), forms the floor of the proximal part of the popliteal fossa. The continuity of the proximal part of the medial epicondylic line is but faintly marked, being interrupted by a wide and faint groove along which the popliteal artery passes to enter the fossa of that name. Distally, where the line ends on the proximal and medial surface of the medial epicondyle, there is a little spur of bone called the adductor tubercle, to which the tendon of the adductor magnus is attached, and behind which the medial head of the gastrocnemius muscle takes origin.
The linea aspera affords extensive linear attachments to many of the muscles of the thigh. The vastus medialis arises from the spiral line proximally and the medial lip of the linea aspera distally. This muscle overlies but does not take origin from the medial aspect of the body. The adductor longus is inserted into the medial lip about the middle third of the length of the body. The adductor magnus is inserted into the intermediate part of the line, extending to the level of the trochanter minor, where it lies medial to the insertion of the gluteus maximus, Distally, its insertion passes on to the medial epicondylic ridge, reaching as far as the adductor tubercle. The adductor brevis muscle is inserted into the linea aspera proximally, between the pectineus and adductor longus muscles medially and the adductor magnus laterally. Distal to the insertion of the gluteus maximus the short head of the biceps arises from the lateral lip as well as from the lateral epicondylic line; in front these also serve for the origin of the vastus lateralis muscle. There is frequently a small tubercle which marks the distal attachment of the lateral intermuscular septum on the lateral condylic line, about two inches from the condyle. Immediately proximal to this there is often a groove for a large muscular artery which pierces the septum at this point (Frazer).
The canals for the nutrient arteries of the body, which have a proximal direction, are usually two in number, and are placed on or near the linea aspera--the proximal one about the level of the Junction of the middle and proximal third of the bone, the distal some three or four inches distal
to this usually on the medial side of the body, immediately in front of the medial lip of the . linea aspera.
The anterior and lateral aspects of the body are covered by, and furnish surfaces for, the origins of the vastus lateralis and vastus intermedius. The medial aspect is covered by the vastus medialis.
The distal extremity of the femur comprises the two condyles and epicondyles. The condyles are two recurved processes of bone, each provided with an
HEAD OF GAS
POSTERIOR CRUCIATE ANTERIOR CRUCIATE
articular surface, and separated behind by a deep intercondyloid fossa. United in front, where their combined articular surfaces form an area on which the patella rests, the two condyles differ from each other in the following respects: If the body of the bone is held vertically, the medial condyle is seen to reach a more distal level than the lateral; but, as the femur lies obliquely in the thigh, the condyles are so placed that their distal surfaces lie in the same horizontal plane. Viewed on their distal aspect, the medial condyle is seen to be the narrower and shorter of the two. The lateral condyle is broader, and advances farther forward and to a more proximal level on the anterior surFIG. 241.-POSTERIOR ASPECT OF DISTAL face of the shaft. The intercondyloid fossa reaches PORTION OF THE RIGHT FEMUR WITH forwards as far as a transverse line drawn through ATTACHMENTS OF MUSCLES MAPPED the centre of the lateral condyle. Its sides are formed by the medial and lateral surfaces of the lateral and medial condyles respectively, the latter being more deeply excavated, and displaying an oval surface near its distal and anterior part for the attachment of the posterior cruciate ligament of the knee-joint. On the posterior and proximal part of the medial surface of the lateral condyle there is a corresponding surface for the attachment of the anterior cruciate ligament. The floor of the notch, which is pierced by numerous vascular canals, slopes proximally and dorsally towards the popliteal surface on the back of the body, from which it is separated by a slight ridge (linea intercondyloidea) to which the posterior part of the capsule of the knee-joint is attached.
Epicondyles. The cutaneous aspect of each condyle (i.e. the lateral surface of the lateral condyle and the medial surface of the medial condyle) presents an elevated rough surface called the epicondyle, the medial (epicondylus medialis) projecting more prominently from the line of the body; capped proximally by the adductor tubercle, it affords attachment near its most prominent point to the fibres of the tibial collateral ligament of the knee-joint. The epicondylus lateralis (lateral epicondyle), less pronounced and lying more in line with the lateral surface of the body, is channelled behind lateral ligament by a curved groove, the distal rounded lip of which serves to separate it from the distal articular surface. This groove ends in front in a pit which is placed just distal to the most salient point of the tuberosity; hereto is attached the tendon of the popliteus muscle, which, in the extended position of the joint, overlies the distal lip of the groove, which is often indented for it, but slips into and occupies the groove when the joint is flexed. Dorsal to the most prominent part of the lateral epicondyle, and just proximal to the pit for the attachment of the popliteus, the fibular collateral ligament of the knee-joint is attached, whilst proximal to that there is a circumscribed area for the origin of the tendinous part of the lateral head of the gastrocnemius muscle.
FIG. 242.-DISTAL END OF THE RIGHT FEMUR (Lateral Side).
The articular surface on the distal extremity is divisible into three partsthat which corresponds to the distal surface of the body and is formed by the coalescence of the two condyles in front; and those which overlie the distal and posterior aspects of each of those processes. The former is separated from the latter by two shallow oblique grooves which traverse the articular surface from before backwards, on either side, in the direction of the anterior part of the intercondyloid fossa. These furrows are the impressions in which fit the anterior parts of the medial and lateral menisci of the knee-joint, respectively, when the knee-joint is extended. The anterior articular area or patellar surface is adapted for articulation with the patella. Convex proximo-distally, it displays a broad and shallow central groove, bounded on either side by two slightly convex surfaces. Of the two sides, the lateral is the wider and more prominent, and rises on the front of the bone to a more proximal level than the medial, thus tending to prevent lateral dislocation of the patella. The condylar or tibial surfaces are convex from side to side, and convex from before backwards. Sweeping round the distal surface and posterior extremities of the condyles, they describe a spiral curve more open in front than behind. The medial condylar articular surface is narrower
than the lateral, and when its distal aspect is viewed it is seen to describe a curve around a vertical axis. Along the lateral edge of this, and in front, where it bounds the intercondyloid fossa, is a semilunar articular area, best seen when the bone is coated with cartilage. This articulates with the medial edge of the patella in extreme flexion of the joint. The articular surface of the lateral condyle is inclined obliquely from before backwards and slightly laterally. The surfaces of the condyles proximal to the articular area posteriorly are continuous with the popliteal surface of the shaft. The area from which the medial head of the muscle springs is often elevated in the form of a tubercle placed on the distal part of the popliteal surface of the body, just proximal to the medial condyle.
The proportionate length of the femur to the body height is as 1 is to 3.53-3-92. Arterial Foramina. Numerous vascular canals are seen in the region of the neck, at the bottom of the trochanteric fossa, in the fossa for the ligamentum teres, on the intertrochanteric crest, and on the lateral surface of the greater trochanter. The nutrient arteries for the body pierce the bone in a proximal direction on or near the linea aspera. Both the back and the front of the distal end of the body display the openings of numerous vascular canals, and the floor of the intercondyloid fossa is also similarly pierced.
Connexions. The femur articulates with the hip bone proximally and the tibia and patella distally. The lateral surface of the greater trochanter determines the point of greatest hip width in the male, being covered only by the skin and superficial fascia and the aponeurotic insertion of the gluteus maximus. In the erect position the tip of the trochanter corresponds to the level of the centre of the hip-joint. When the thigh is flexed the trochanter major sinks under cover of the anterior fibres of the gluteus maximus. In women the hip width is usually greatest at some little distance distal to the trochanter, due to the accumulation of fat in this region. The body of the bone is surrounded on all sides by muscles. Its forward curve, however, is accountable to some extent for the fulness of the front of the thigh. The exposed surfaces of the condyles determine to a large extent the form of the knee. In flexion the articular edges can easily be recognised on either side of and distal to the patella.
Sexual Differences.-According to Dwight, the head of the femur in the female is propor tionately smaller than that of the male.
Ossification. The body begins to ossify early in the second month of foetal life, and at birth displays enlargements at both ends, which are capped with cartilage. If at birth the distal cartilaginous end be sliced away, a small ossific nucleus for the distal epiphysis will usually be seen. This, as a rule, makes its appearance towards the latter end of the ninth