1516 



puytren having failed at the first attempt, he 

 succeeded in reducing the luxation by inclin- 

 ing the hand forcibly to the radial side, and 

 pushing with his two thumbs, united the dis- 

 placed extremity of the ulna inwards and 

 backwards. By this process the reduction 

 was affected. The patient cried out at once, 

 " I am well." All deformity had disappeared, 

 and the motion of pronation and snpination 

 were restored. (Gazette Medical, Malgaigne.) 



Such cases as these, says Dupuytren, ought 

 to be recorded by every surgeon when he 

 meets with them, in consequence of their 

 rarity and importance. 



Luxation of the bones of the carpus. The 

 bones of the carpus are united to each other 

 so solidly, and their movements are so limited, 

 that without experience, we should be dis- 

 posed to pronounce luxation of any of these 

 bones impossible. Nevertheless, the head of 

 the os magnum may be dislocated from the 

 cavity formed for it by the scaphoid and semi- 

 lunar bones. The first range of the bones of 

 the carpus is articulated with the bones of the 

 second range in such a manner that slight 

 gliding movements of flexion and extension of 

 the hand are permitted, which augment a little 

 the movements of flexion aud extension of 

 the hand upon the forearm, and add some- 

 what, as Cruveilhier sajs, to the grace of the 

 movements of this portion of the upper ex- 

 tremity. In flexion, the head of the os mag- 

 num, which is somewhat inclined backwards, 

 raises up the thin capsule which surrounds 

 its articulation, and if this movement be 

 carried very far, the capsule and accessory 

 fibres which support the bone posteriorly are 

 broken, and the os magnum escapes from the 

 cavity in which it is naturally placed ; the dis- 

 location cannot be called complete, yet the 

 os magnum passes somewhat the level of the 

 posterior surface of the other bones of the 

 carpus. 



The accident is more common in women 

 than in men, no doubt because the ligaments 

 are weaker and the bones enjoy greater 

 motion in the former, than in the latter. The 

 luxation backwards of the os magnum, the 

 only one which can occur, is always the result 

 of a forced and violent flexion of the wrist, 

 such, for example, as a fall on the back of the 

 hand would produce. We recognise the lux- 

 ation of the os magnum by the history of the 

 accident, and by the deformity produced. We 

 perceive a hard, circumscribed tumour, which 

 has suddenly appeared on the back of the 

 hand, in the situation which corresponds to 

 the head of the bone. This tumour becomes 

 more prominent when the hand is flexed, and 

 diminishes when it is extended : we can make 

 it disappear entirely by a slight compression. 

 This luxation causes but little inconvenience ; 

 but the head of the os magnum always remains 

 more salient when the hand is flexed, and 

 forms a tumour, more or less marked, accord- 

 ing to the extent of the displacement. 



We can easily reduce this luxation by ex- 

 tending the hand, or by exercising a slight 

 pressure on the head of the os magnum ; but, 



WRIST-JOINT (ABNORMAL ANATOMY). 



although it is easy to make the bone resume 

 its position in the cavity formed for it by the 

 scaphoid and semi-lunar bones, it is very dif- 

 ficult to maintain it there, and the incon- 

 venience and deformity resulting from the 

 luxation are so trivial, that few persons will 

 submit with patience to the means usually 

 recommended. 



Fractures of the lower extremity of the radius 

 in the immediate vicinity of the wrist-joint. 

 We believe that the first important effort to 

 direct attention to the peculiarities which the 

 fracture of the lower extremity of the radius 

 presents, was made by the late professor of 

 surgery, of the College of Surgeons, in Dublin, 

 Dr. A" Colles, in the year Isi4-.* Subse- 

 quently, we find Sir A. Cooper, in London, 

 and Dupuytren, in Paris, each pointing out 

 the importance, in a practical point of view, 

 of our studying this accident, and distin- 

 guishing the case of fracture of the radius 

 with displacement backwards of the carpus, 

 from true dislocation backwards of the hand 

 at the wrist-joint. 



Velpeati followed these, concurring with 

 them in the opinion that a transverse frac- 

 ture of the lower extremity of the radius 

 was a very common injury, and frequently 

 mistaken for a dislocation. He seemed to be 

 even more positive than his predecessors in 

 maintaining the doctrine that no accidental 

 luxation of the wrist-joint could occur with- 

 out a fracture of some of the bony processes, 

 or laceration of the integuments. 



This fracture is rarely attributable to any 

 direct cause ; it appears, however, that Hub- 

 lier communicated to the Academy of Medi- 

 cine the case of a young girl, who having had 

 the wrist caught between the pole of a car- 

 riage and a wall, had gotten a transverse frac- 

 ture of the lower extremity of the radius. In 

 this case there was combined with the above 

 mentioned transverse fracture, another vertical 

 one at right angles with it, dividing into two 

 the lower fragment, constituting what in 

 other articulations we have elsewhere in this 

 book (vide KNEK, ELBOW) denominated a 

 T fracture. This species of fracture by direct 

 violence, corresponds much to the cases de- 

 scribed by Dupuytren as " Fracture par ecrase- 

 ment." Fractures of the radius may be caused 

 by falls on the back of the hand, but by far 

 the most frequent sources of the fracture in 

 question are falls on the palm. 



Malgaigne asks, by what mechanism are 

 these fractures of the lower extremity of the 

 radius specially produced. In reply he ad- 

 duces the following experiment by Nelaton : 

 The latter amputated the forearm of a dead 

 body at the elbow, and cut off the olecronon 

 at a level with the head of the radius. He 

 then applied the palm of the hand of the sub- 

 ject on a solid plane, the forearm being at 

 the same time directed vertically; he now 

 with a mallet struck a heavy blow directly on 

 the superior extremity of the two bones of 



* Vide Edinb. Mod. and Surgical Journal, vol. x. 

 1814. 



