THE HAND. 



upon the radial border of the base of the hand, which is produced by the tendons of the extensor 

 OSM metacarpus and extensor brevis pollicis muscles. Two centimeters posterio o the" 

 tendons may be easily seen and felt the tendon of the extensor longus pollicis its way to th" 

 These prominences are separated by a fossa, the so-called tabatiere or "snuff-box" 

 which holds an important relation to the course of the radial artery (see page 86). Upon the 

 dorsal surface of the hand may also be noted the network of subcutaneous veins and the extensor 

 tendons which become more prominent when the fingers are moved. As the extensor tendons 

 approach the wrist they disappear from view, since they enter their sheaths in this situation 



Upon the dorsal aspect of the hand the metacarpal bones and the phalanges may be easily 

 palpated, while the palmar surface of these structures is well covered by the soft parts If the 

 >rsal surface of the base of a slightly flexed finger is palpated by the thumb and index-finger of 

 )ther hand, the metacarpophalangeal joint and the thick base of the first phalanx may be 

 easily recognized. In the closed fist the line of this metacarpophalangeal joint js one centimeter 

 ow (i. e., towards the nail) the most prominent portion of the knuckle, and the same statement 

 for all of the interphalangeal joints. This is something that must be felt, if disarticulations 

 ; to be performed at these joints lege artis. If the hand is not too fat, the joint between the 

 rapezmm and the first metacarpal bone (saddle-joint) may be palpated at the base of the thenar 

 nnence by following the course of the metacarpal bone with the finger. If the hand is laid 

 palm downward upon a table and the finger is passed backward in the groove between the second 

 and third metacarpal bones, it reaches the " dorso-radial " fossa (Rotter), which is filled out 

 during dorsal flexion of the hand by the tendons of the extensor carpi radialis longior and brevior. 

 The location of this fossa is important for operative procedures (dorso-radial incision of Langen- 

 beck for resection of the wrist-joint). 



The palmar jascia radiates from the tendon of the palmaris longus and is situated beneath 

 the subcutaneous fat of the palm. It is the fascia which is responsible for Dupuytren's finger 

 contraction. Together with the tough skin of the palm, it forms a dense layer of tissue which resists 

 the spontaneous perforation of inflammatory processes deeply situated in the palm. It divides 

 into five slips which are adherent to the skin at the bases of the fingers and of the thumb; in 

 hands which are not too lean, the skin of the interdigital folds forms small elevations which are 

 due to the projection of the subcutaneous fat between these slips. The transverse ligament runs 

 between and connects the slips passing to the four fingers. The fascia is considerably thinner 

 over the thenar and hypothenar eminences. 



The deep fascia of the forearm is reinforced over the wrist-joint by transverse fibers which 

 form the anterior and posterior annular ligaments. The latter is of interest to the practitioner on 

 account of its relation to the extensor tendons. The posterior annular ligament passes trans- 

 versely from the styloid process of the radius to the styloid process of the ulna and forms six com- 

 partments for the tendons by giving off septa to the radius and ulna. These compartments or 

 tendon-sheaths, though much less frequently affected than the palmar compartment (see page 

 87), are occasionally the seat of tendovaginitis. Passing from the radial to the ulnar side the 

 compartments are as follows: (i) For the tendons of the extensor ossis metacarpi pollicis and of 

 the extensor brevis pollicis; (2) for the tendons of the extensor carpi radialis longior and brevior; 

 (3) for the tendon of the extensor longus pollicis; (4) for the tendons of the extensor communis 



