1508 



WRIST-JOINT (ABNORMAL ANATOMY). 



intervenes between the carpus and that bone. 

 These circumstances taken in connection with 

 the remarkable mobility of the lower radio- 

 ulnar articulation sufficiently explain why the 

 ulna so frequently escapes injury from forces 

 which act on the hand, and which suffice to 

 fracture the radius. At the same time it is to 

 be observed, that displacements of the lower 

 extremity of the ulna are by no means unlre- 

 quent accompaniments of fractures of the 

 radius. 



(Benjamin Gco. M' Dowel.) 



WRIST, ABNORMAL CONDITIONS OF. 

 In the following account of the abnormal con- 

 dition of the different structures which enter 

 into the composition of the wrist, we shall 

 consider this region as formed not only by the 

 lower extremities of the bones of the forearm 

 and the wrist-joint, properly so called, but 

 also by the carpus surrounded by its fibrous 

 and fibro-synovial tissues. 



The abnormal condition of the different 

 .structures of this region mav be arranged uu- 



C 1 ./ O 



tier those which we can refer 1st, to conge- 

 nital malformation; 2nd, to accident; and 3rd, 

 to disease. 



CONGENITAL. Congenital dislocation of 

 the bones which constitute the radio-carpal 

 articulation may be considered rare; never- 

 theless, I have seen within these few years 

 thirteen examples of this malformation. One, 

 in which the bones of the forearm were 

 thrown forwards and the carpus backwards. 

 In the remaining twelve cases, the bones of 

 the forearm were placed on the clorsum of the 

 carpus, which they overlapped. 



The history of congenital luxations of the 

 wrist-joint is modern. Cruveilhier, in his 

 Pathological Anatomy (liv. ix., 1833), has 

 published an example of this deformity, al- 

 though he was not himself aware of the true 

 nature of the case. The example he adduces 

 is that of an adult female, concerning whose 

 history, unfortunately, he could learn nothing. 

 In this case the forearm was preternaturally 

 short, and it formed a right-angle with the 

 hand, which besides was inclined to the 

 radial side of the forearm; extension was im- 

 2)ossible ; flexion, to a certain degree, was per- 

 mitted ; the inferior extremities of the radius 

 and ulna were dislocated backwards, and 

 formed a very considerable prominence be- 

 neath the skin posteriorly. 



The extremity of the radius was less salient, 

 and descended much less than that of the ulna. 

 The superior extremity of the carpus could be 

 felt on a plane which was superior and ante- 

 rior to that of the inferior extremity of the 

 bones of the forearm. 



Dissection. The bones of the carpus were 

 found on dissection to be in a state of atrophy, 

 and more or less malformed ; the radius, .short- 

 ened and deformed, scarcely measured five 

 inches; the deformity principally affected its 

 lower extremity, which was large and deeply 

 grooved posteriorly for the reception of the 

 tendons of the extensor muscles; the articular 

 surface for the carpus was placed on the an- 



terior aspect of the bone; the ulna was only 

 six inches and a half in length, its lower ex- 

 tremity, much smaller than normal, descended 

 half an inch below the carpal extremity of the 

 radius. 



Fig. 924. 



Forearm, Cruveilhier's case. 



The carpus was much deformed, particu- 

 larly as to the first row, which was merely, we 

 may say, in a rudimentary state. The pisi- 

 form was the only bone of this first range that 

 was normal. The bones of the second or 

 metacarpal row participated in the deformity. 

 The head of the os magnum was altogether 

 absent, and the unciform was imperfect. 



Cruveilhier published the foregoing case, 

 erroneously supposing it an example of dislo- 

 cation of the wrist-joint, the result of accident. 

 Dupuytren and Marjolin disagreed with Cru- 

 veilhier, but equally mistook the true nature 

 of this case ; they, doubting the possibility of 

 an accidental luxation of the wrist-joint, con- 

 sidered that all the phenomena which the 

 post-mortem examination of the limb presented 

 in Cruveilhier's example, might be accounted 

 for by supposing the case to have been one of 

 fracture of the radius, and consecutive dis- 

 placement of the ulna. 



It must ever appear as a matter of surprise 

 that Cruveilhier could have supposed that this 

 case just adduced was an old accidental luxa- 

 tion left unreduced, because, according to such 

 an hypothesis, neither the arrest of develop- 

 ment as to the length of the forearm (which 

 only measured six inches and a half), nor the 

 abnormal appearances observed in the bones 

 of the carpus, could have been satisfactorily 

 accounted for, or explained. 



It is equally difficult to imagine how it was 

 that Dupuytren, who had his attention so 

 much alive to the subject of congenital luxa- 

 tions, should have overlooked the true nature 

 of Cruveilhier's case, and referred the pheno- 

 mena it presented to the circumstance of the 

 radius having been broken through its lower 

 epiphysis; no one ever heard of shortening of 

 the radius to this amount as the result of frac- 

 ture ; besides, the bones on the carpus were in 

 a state of atrophy, and the ulna, which Du- 



