164 SURGICAL ANATOMY OF THE PALM. 



radialis indicis arteries, metacarpal bone of thumb, tra- 

 pezium, and tendon of flexor carpi radialis. 



In the middle segment of the palm, beneath the central 

 fasciculus of the palmar fascia and the anterior annular 

 ligament, with which the fascia is continuous, lies the 

 superficial palmar arch and its digital branches, the ul- 

 nar and median nerves with their digital branches, the 

 tendons of the flexor sublimis and profundus digitorum, 

 with which latter are associated the lumbricales (these 

 muscles inclosed in their sy no vial sheaths), next a layer 

 of fibrous tissue separating them from the deep arch, the 

 deep branch of the ulnar artery, the adductor of thumb 

 and interossei, whose tendons with those of the lumbri- 

 cales pass into the general dorsal aponeurosis, and lastly, 

 the metacarpus. 



Beneath the palmar fascia of the hypothenar eminence 

 lie the palmaris brevis, some cutaneous vessels and nerves, 

 the abductor and flexor brevis, minimi digiti, commence- 

 ment of superficial palmar arch, with its accompanying 

 ulnar nerve, opponens minimi digiti, deep branch of ul- 

 nar artery and nerve, and fifth metacarpal bone. 



The metacarpal bone of the thumb articulates with 

 the trapezium by a saddle-shaped surface, and its shaft 

 is considerably curved anteriorly; and in amputation at 

 the metacarpo-trapezial joint, the secret of enucleating 

 the bone neatly consists in abducting it forcibly and di- 

 viding the lateral ligaments, of which it is better to cut 

 the inner one first. There are several methods of per- 

 forming this operation, but that should always be chosen 

 which will leave the greatest amount of opposing tissue; 

 as the muscular pad, resulting from the flaps, even 

 though it lose its bony support, is of great importance 

 when the hypothenar mass of muscle is intact, as it will 



