SURGICAL ANATOMY OP THE PALM. 165 



in great measure retain the power of approximation. 

 Care must be taken to avoid wounding the trunk of the 

 radial artery as it passes between the two heads of the 

 first dorsal interosseous muscle, if possible. The meta- 

 carpal bones of the fingers, having a common synovial 

 membrane with their carpal bones, ought, if possible, to 

 be removed without disarticulation, owing to the lia- 

 bility of general suppuration. There is some little diffi- 

 culty attending amputation of the fifth metacarpal bone, 

 owing to its double articulation with the os cuneiforme. 



Abscess in the palm (palmar abscess), unless opened 

 early, is liable to spread up the arm, along the synovial 

 sheaths of the muscles, by passing beneath the annular 

 ligament, the excruciating pain attending it being due 

 to the tenseness of the palmar fascia. In opening col- 

 lections of pus in the palm, the position of the palmar 

 arch must be recollected, and the knife should be entered 

 upon the head or neck of the metacarpal bone, and not 

 between the fingers, so that the bifurcation of the digital 

 artery may be avoided. 



In wounds of the palmar arch, if ligature of the radial 

 and ulnar fail, the circulation is probably carried on by 

 an enlarged anterior interosseous or comes nervi medi- 

 ani, and ligature of the brachial must be had recourse to. 



Bursal tumors are commonly met with in association 

 with the synovial sheaths of the flexor tendons in the 

 palm, and generally communicate beneath the annular 

 ligament, with the continuation of these sheaths in the 

 forearm. 



In the fingers the skin is very thick, particularly on 

 the palmar aspect, highly vascular, and freely supplied 

 with nerve-fibres. The subcutaneous tissue contains a 

 good deal of fat ; beneath this tissue is the sheath or 



