1204 SURFACE AND SURGICAL ANATOMY. 
reached it lies 1 in. below the condyles, and in a plane anterior to the posterior 
surface of the lower end of the humerus. The head of the radius, which lies nearly 
1 in. below the external epicondyle, is best manipulated from behind by placing 
the thumb upon it, while the semi-flexed forearm is being alternately pronated 
and supinated. Upon the outer part of the posterior aspect of the extended 
elbow is a distinct dimple, which overhes the radio-humeral articulation; this 
dimple, along with the hollows on either side of the olecranon, becomes effaced in 
synovial thickenings and effusions into the joint. The coronoid process is situated 
too deeply to be distinctly felt. The lower epiphysis of the humerus includes the 
articular portion of the lower extremity and the external condyle; it is, therefore, 
small and almost entirely intra-articular, so that foci of disease in its neighbour- 
hood soon invade the cavity of the joimt. The internal epicondyle ossifies as a 
Vena comes of brachial artery Brachial artery 
Musculo-cutaneous nerve | Median-basilic VAR ; 
Tendon of biceps \ | £ Vena comes of brachial artery 
yPronator radii teres 
< NN / Ulnar vein 
: a 
Median nerve 
: \ Brachialis anticus 
Wa. origin of 
} flexor muscles 
Ulnar nerve 
Musculo-spiral 
nerve 
Internal condyle 
Radial extensors-\ 
Inferior profunda 
artery 
Articular surface of humerus 
/ 
External condyle 
Anconeus Olecranon fossa of humerus 
Fic. 811.—TRANSVERSE SECTION THROUGH THE BEND OF THE ELBOW. 
separate epiphysis which unites with the lower end of the diaphysis. In the com- 
monest dislocation of the elbow, viz. with backward displacement of both bones of 
the forearm, the normal relative position of the bony points is lost, whereas in a 
transverse supracondyloid fracture the normal relations are maintained. In the 
child the head of the radius is relatively smaller, and less firmly kept in position 
by the orbicular ligament than in the adult, so that it is liable to be partially 
dislocated, giving rise to the condition known as “pulled elbow.” To evacuate 
pus from the elbow-joint a vertical incision should be made over the dorsal aspect 
of the joint, immediately external to the olecranon. 
The median vein is seen to bifurcate into median basilic and median cephalic 
+ in. below the middle of the bend of the elbow; opposite the same point, but 
beneath the deep fascia, is the bifurcation of the brachial artery. The median basilic 
and median cephalic veins diverge as they ascend one on either side of the biceps 
tendon; the larger of the two veins, viz. the median basilic, is usually selected for 
the operations of venesection and transfusion. When the elbow is flexed the biceps 
tendon can be traced vertically through the centre of the bend of the elbow almost to 
its insertion. Passing downwards and inwards from the inner edge of the tendon is 
the bicipital fascia, which separates the median basilic vein from the brachial artery. 
If the finger nail be insinuated beneath the inner edges of the fascia the point of the 
finger will rest upon, and feel the pulsations of, the brachial artery. The median 
nerve descends through the space a little internal to the brachial artery. The 
bifurcation of the musculo-spiral nerve takes place in front of the external condyle 
