1518 



WRIST-JOINT (ABNORMAL ANATOMY). 



take place at a point which is below the level Cooper, who asserts that in this fracture a 

 of this line, and any displacement, the result very powerful extension is required to brin^ 



^A* /* n A.. . 1*1 _ nr A\ i I A L A! i I . i r* . i i" 



of fracture, cannot readily affect the breadth 

 of the interosseous space, placed above the 

 line of the fracture. 



Fig. 931. 



It is only in cases where the fracture is 

 situated so high as an inch and a half, or 

 more, above the joint, that any abnormal ap- 

 proximation of the bones towards each other, 

 and ultimate obliteration of the interosseous 

 interval is to be dreaded. 



Although therefore, as a result of Colles' 

 fracture, we observe the forearm assume, near 

 the wrist-joint, a cylindroidal form, there may 

 be no real narrowing whatever, but the ap- 

 pearance of it may be attributed rather to an 

 increase, in the antero-posterior diameter of 

 the region of the wrist, than to any real 

 diminution which occurs transversely. 



Malgaigne has, however, adduced an example 

 to explain how, in certain rare cases, a diminu- 

 tion of the transverse diameter of the forearm 

 may occasionally take place, and by the 

 action of the pronator quadratus not on the 

 inferior, but on the upper fragment of the 

 radius. (/. 932.) 



It is said by some, that crepitation, caused 

 by the movements of the fragments of the 

 broken radius on each other, can always be 

 elicited, and that this sign is diagnostic of 

 fracture ; moreover, that the deformity is 

 easy to reduce by extension, but liable to 

 return when the extending force is removed. 

 Such observations, no doubt, may sometimes 

 be made with truth. For our own parts, we 

 do not think that crepitation can, except in a 

 very few cases, be elicited in Colles' fracture 

 of the radius. We have found it to be an 

 injury attended with a deformity which can, 

 it is true, be removed by extension, but our 

 experience corresponds with that of Sir A. 



the broken ends of the radius into apposition. 

 Fig. 932. 



After Malgaigne. 



Diagnosis, In many cases, a fracture of the 

 radius in the immediate vicinity of the wrist- 

 joint is attended with so much deformity, and 

 accompanied with such characteristic appear- 

 ances, that the observation of Pouteau appears 

 well founded, that it can be recognised at the 

 first "coup d'oeil ;" but on the other hand, 

 there are some cases in which very little ex- 

 ternal evidence of any fracture can, without 

 careful examination, be detected. The un- 

 dulating curve, which has been compared to 

 that represented by a silver fork, cannot exist 

 without fracture, and the elevation from the 

 level of the back part of the radius of the 

 common extensor tendons is another feature, 

 which we believe with Velpeau to be peculiar 

 to fracture ; we know that in the normal 

 state the tendons of the extensor carpi radialis 

 longior and brevior remain applied as longi- 

 tudinal bands, lying flat on the posterior 

 surface of the radius, and no interval whatever 

 exists between these two bands and the back 

 part of this bone near to the wrist. Now, 

 when there is a fracture of the radius here, 

 this bone is rendered somewhat concave on its 

 posterior surface, and these tendons must, of 

 necessity, abandon the bony surface, and be 

 raised up several lines from 'it, so as to repre- 

 sent a cord, more or less tense, but easy 

 to depress. If, for example, the hand of 

 the patient being a little flexed, the surgeon 

 in examining these cases, places his finger or 

 thumb three or four lines above the level of 

 the wrist-joint, on the posterior surface, and 

 near to the external border of the radius, he 

 will, if fracture exist, recognise beneath the 



