CASE of congenital luxation of the wrist-joint of both bones of the left fore arm backwards.
The writer exhibited to a meeting of the Surgical Society of Dublin, on March 20th, 1847, the cast of the left forearm of an adult female, who had been born with a luxation of the carpal extremity of both the bones of the left forearm backwards. The lower ex tremities of the radius and ulna were placed completely on the dorsum of the carpus, while the hand was, consequently, situated in the front of these bones.
This remarkable cast of congenital luxa tion of the wrist-joint was sent across the Atlantic by Dr. R. MacDonnell, now holding, as a surgeon of the Montreal Hospital, a distinguished place in British America.
We observe that in the casts (figs. 928. and 929., the representations of Dr. H. MacDon nell's case), the hand is well formed, but that the forearm is much shorter than it should be, being very little longer than the hand ; the whole length of the forearm is not eight inches, while that of the hand, measured in its greatest length, amounts to six inches and one half. The forearm in its upper part is round and muscular ; as we examine it towards the hand , it assumes a well marked quadrilateral form, and we observe a projection on the dorsum of the carpus posteriorly, obviously formed by the lower extremities of the radius and ulna, which are dislocated backwards. The lower extremity of the forearm at the wrist here exhibits a very oblique termination, the ulna having passed, by fully an inch, the carpal ex tremity of the radius.
When we place the forearm on its palmar aspect, as on a table, and view the ulnar side of it, we notice that the ulna rides conspi- cuously on the back of the carpus, being its ts level about an inch ; and at the same time that the ulna has passed so far downwards on the back of the carpus as to reach even to the upper extremity of the metacarpal bone of the little finger (see fig.
929.). The radius at its lowest part, besides being thus shorter than the ulna, is much less salient on the dorsum of the carpus.
The upper extremity of the carpus and the hand are placed, as has been mentioned, an teriorly to, and somewhat above, the lowest extremity of the radius and ulna, and conse quently the measurement of the antero-pos terior diameter of the wrist is much increased ; the whole forearm is somewhat bowed, pre senting on its anterior aspect a concavity in the longitudinal direction. Near the wrist joint the tendons of the flexor carpi ulnaris on the inner side, and of the flexor carpi ra dialis on the outer, or radial side, are thrown into strong relief, and thus contribute to give the quadrilateral form to the wrist above alluded to.
Since the writer made this communication to the Surgical Society of Dublin, he has seen other cases of congenital luxation at the wrist-joint of both the bones of the forearm backwards on the dorsum of the carpus. They so strongly resembled the cases just now adduced, that he refrains from entering into particulars. From all these last men tioned, the individuals practically suffered little from the defect.
From the cases the writer has seen or in vestigated, he may draw the following conclu sions : 1st. That the case of D. O'Neil, brought before the Pathological Society of Dublin, Dec. 15th, 1838, by the writer, was the first example laid before the profession with the intention of proving that such a lesion as a congenital luxation of the wrist-joint existed.
2nd. That Cruveilhier's case, adduced five years previously, as a case of an old unreduced luxation of the wrist-joint, and considered by Dupuytren as a fracture of the radius and dislocation of the ulna, and since misinter preted by others, must hereafter be looked upon as an excellent example of congenital luxatiou of both the bones of the forearm backwards at the wrist-joint.
3111. That the case sent to Dublin by Dr. MacDonnell of Montreal, is another exam ple of a congenital luxation of the bones of the fore-arm at the wrist-joint backwards.