1520 



WRIST-JOINT (ABNORMAL ANATOMY^). 



extended than before ; the pain disappears, 

 and in about a month after the fracture has 

 occured, if judicious treatment be adopted, the 

 union of the fragments is so perfect, that the 

 passive motion to restore the joints to their 

 primitive suppleness may be commenced. 



Notwithstanding, therefore, the opinions of 

 Dupiiytren, Diday, &e., &c., we think that, as 

 a general rule, in the case of Colics' fracture 

 the prognosis is favourable. 



It may be otherwise, if the styloid process 

 of the radius be elevated much above its 

 natural level, if the hand has quitted, par- 

 tially, the lower end of the ulna, so as to 

 be carried "par un inouvetncnt de totalite " 



outwards, and if the case has not been early 

 recognised. 



Anatomical characters nfthe Fracture. On 

 dissection, it will be found that the hard 

 swelling which occupies the back part of the 

 hand and wrist, is caused by the displacement 

 backwards of the lower fragment of the radius, 

 and the carpus carried with it in this direction. 

 As a consequence of the altered direction of 

 the radius, we find that the aspect of the 

 carpal articular surface of this bone is altered, 

 and instead of being directed, as it normally 

 is *, downwards and somewhat forwards, it is 

 now directed downwards and backwards ( fig. 

 933.) ; the carpus and metacarpus retaining 



Fig. 933. 



their connexion with the broken radius must 

 always thus follow this bone in its derange- 

 ments, and cause the characteristic dorsal 

 convexity above alluded to. The change of 

 direction of the articular surface of the radius 

 is well shown by measuring the length of the 

 broken radius in these cases, both on the 

 palmar and dorsal aspect of this bone longi- 

 tudinally, when it will be found that in Colics' 

 fracture, the posterior measurement is several 

 lines less than the anterior, which is exactly 

 the reverse of what this measurement normally 

 should be. 



We dwell upon this abnormal ob'iquity of 

 the lower articular surface of the radius, for 

 in the treatment of this injury it should be 

 our principal aim to remedy this obliquity, 

 and, as it were, reverse it, and thus make the 

 aspect of the articular surface look as it 

 should normally do, downwards and forwards. 



The change of direction of the articular 

 surface is caused by the extensor muscles 

 of the carpus, and of the thumb, and by 

 their tendons, which pass along the posterior 

 surface of the ratlins in sheaths, firmly con- 

 nected with the inferior extremity of this 

 bone, to which deviation in the direction of 

 the lower fragment the action of the supinator 

 longus muscle and its tendons may also some- 

 what contribute. 



Professor Smith, who has investigated labo- 

 riously the anatomy of the bones in this injury, 

 says he has discovered nothing to invalidate 

 the truth of the general proposition first main- 

 tained by Voillemicr, namely, that when the 

 radius is broken within an inch of its lower 

 extremity, the direction of the fracture is 

 usually transverse; but we find that he differs 

 entirely from this last-named author upon the 

 doctrine of the fracture of the radius in ques- 

 tion, being one by impaction. It is very true, 

 he says, that in every instance of the ordinary 



fracture of the carpal extremity of the radius, 

 which he had an opportunity of examining 

 anatomically long after the occurrence of the 

 injury, he found upon making a section of the 

 bone, from before backwards, a line of com- 

 pact tissue continuous with the posterior wall 

 of the shaft, extending to a greater or less dis- 

 tance into the reticular texture of the lower 

 fragment; but he cannot agree with Voillemier, 

 that this appearance affords evidence of im- 

 paction of the upper fragment into the lower. 

 In the only recent specimen Mr. Smith had an 

 opportunity of examining, the lower fragment 

 was displaced backwards, the superior pro- 

 jecting one-eighth of an inch in front of it. 

 There was no impaction whatever in this re- 

 cent specimen, of either fragment into the 

 other, nor any line of compact structure pene- 



trating 



the reticular tissue of the lower frae- 



O 



ment. 



If the doctrine of impaction were true, the 

 shortening of the radius in cases of fracture of 

 its lower extremity, should be much greater 

 than it ever is, for there is a second cause of 

 shortening in operation, i.e. the alteration in 

 the direction of the articulating surface, in 

 consequence of which the posterior surface of 

 the radius (naturally longer than the anterior) 

 becomes the shorter of the two. Now, if to 

 the degree of shortening produced by this 

 cause we add that arising from impaction, we 

 should have an amount of shortening much 

 greater than ever occurs in the case of Colles' 

 fracture; indeed, after adducing other argu- 

 ments against the theory of Voillemicr, as to 

 this being a case of fracture by "penetration" 

 Mr. Smith further remarks, that as long as the 

 ulna remains unbroken and the ligamentons 

 connexion between the two bones uninjured, 

 it is scarcely possible for either fragment to 



* We always take it as understood that the 

 patient is in the erect posture. 



