WRIST-JOINT (ABNORMAL ANATOMY). 



1521 



penetrate the other, even to the extent of half 

 an inch. 



We agree with Velpeau, Smith, &c., in 

 thinking that in this injury, Colles' fracture, 

 there is scarcely any diminution of the trans- 

 verse diameter of the forearm. The cylin- 

 droidal form which the arm acquires being 

 owing partly to an effusion among the flexor 

 tendons, but principally to the increase of the 

 antero-posterior diameter of the forearm at the 

 seat of the fracture, consequent on the back- 

 ward displacement of the lower fragment. 



I have never seen the case, spoken of by 

 many, of transverse fracture of the radius, with 

 displacement forwards of the hand and lower 

 fragment, which accident is said to be pro- 

 duced by a fall on the back of the hand. 



Fracture of the lower extremity of the Ulna. 

 A fracture of the lower extremity of the 

 ulna is rather a rare accident, because, per- 

 haps, of the great elasticity of this long and 

 slender bone, and the mobility of its lower 

 end, by which it, as it were, eludes the force 

 which might otherwise cause its fracture. In- 

 deed the ulna, it will be recollected, is not 

 directly connected with the hand as the 

 radius, the " manubrium manus," is : and 

 hence, when a patient falls on the palm of the 

 hand, the whole force of the weight and im- 

 pulse are sustained by the radius ; but if this 

 last bone gives way, and a transverse fracture 

 occurs, with displacement backwards of the 

 hand and lower fragment, then, as a secondary 

 consequence, a fracture of the ulna, near the 

 wrist-joint, may follow. In the vast majority 

 of cases, however, of fracture of the radius 

 close to the wrist, which occur, for example, in 

 Colles' fracture, the ulna remains unbroken. 



Fracture of the lower extremity of the ulna 

 may also be the effect of direct violence. 



When the ulna is broken alone, without 

 being accompanied by any simultaneous frac- 

 ture of the radius, it may be recognised by the 

 pain felt by the patient when direct pressure 

 is made on "the broken part of the ulna, and by 

 the difficulty he experiences whenever he 

 attempts to pronate or supinate the forearm. 

 When the surgeon takes hold of the lower 

 fragment of the ulna, and moves it backwards 

 and forwards, crepitation can be felt. 



Fracture of the lower extremity of the ulna 

 is an accident which requires much attention 

 from the surgeon, as sometimes, if the sepa- 

 rated fragment be small, as, for. example, con- 

 sisting merely of the styloid process of the 

 ulna, no union may occur, and permanent 

 weakness of the wrist-joint may follow. 



Disjunction of the lower J^pip/ii/sis of the 

 Radius. This must be considered rather a 

 rare accident ; it is, however, occasionally to 

 be met with ; and the history of the art of 

 surgery furnishes us with well-marked ex- 

 amples of it, as the three following cases 

 sufficiently prove: 



CASE!. "I have," says Cloquet, " ob- 

 served one case of the disjunction of the 

 lower epiphysis of the radius, in a young lad 

 twelve years of age, who fell from a consi- 

 derable height from a tree to the ground. 



VOL. IV. 



Besides the injury done to the radius, he 

 received, at the time of the fall, a wound of 

 the head which in three days proved fatal to 

 him." 



Dissection. The epiphysis of the right 

 radius was entirely separated, and a great 

 quantity of blood was effused in the deeper 

 palmar region, behind the tendons of the deep 

 flexor muscles of the fingers (Diction, de 

 Medecine, 1824). 



CASE 2. Rognetta has adduced a similar 

 case of a lad at fifteen years (Gazette Medi- 

 cale, 1834.). 



CASE 3. In December 1 5th, 1838, the 

 writer laid a case before the Pathological 

 Society of Dublin, which was a true speci- 

 men of a disjunction of the lower epiphysis of 

 the radius. 



The patient, having been above eighteen 

 years of age, had attained to a more mature 

 time of life than any other example of this 

 special injury affecting the wrist hitherto 

 recorded ; a representation of the external 

 appearance which the lower part of the fore- 

 arm and carpus presented in this case have 

 been preserved by a plaster cast ; and after 

 the death of the patient, the actual condition 

 of the parts having been ascertained anato- 

 mically, these circumstances, in the writer's 

 opinion, make this case valuable. 



A. B., aet. eighteen, a mason, fell from a scaf- 

 fold which was attached to the front of a lofty 

 house at its third story. By the fall he re- 

 ceived a severe injury of the head, which 

 rendered him immediately insensible, and in 

 this condition was admitted into the Richmond 

 Hospital. Besides the injury of the head, we 

 noticed in this case a remarkable lesion ; the 

 right wrist had suffered a derangement, accom- 

 panied with a deformity that at first sight we 

 might suppose would be produced by a dislo- 

 cation of the carpus and hand backwards on 

 the dorsum of the forearm (fig. 93k). The 

 plane of the hand and carpus were placed fully 

 three quarters of an inch behind the plane of 

 the rest of the forearm ; and from the external 

 appearances there seemed no doubt but that 

 there was an abrupt transverse solution of 

 continuity of the forearm, close to the wrist- 

 joint, which equally affected both radius and 

 ulna. 



On viewing the limb laterally, the peculiar 

 curve which Velpeau compared to the hack of 

 a silver dinner fork, was exaggerated beyond 

 what we noticed in the ordinary fracture of the 

 radius in this situation; and the tendons of the 

 extensors, particularly those of the extensor 

 carpi, were thrown remarkably into relief. 

 The anterior, or palmar surface of the fore- 

 arm presented a longer and more uniform 

 curve than the posterior ; the depth of the 

 antero-posterior diameter of the wrist in the 

 seat of injury was much increased : so that 

 this and the bilateral measurement seemed 

 equal. 



Thus the accident presented many of the 

 appearances of the dislocation, backwards, of 

 the hand and carpus ; but the longitudinal 

 measurement, taken from the highest part of 



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