e. Congenital or original luxation of the superior extremity of the radius backward. Dupuytren is the first pathologist who has spoken of the congenital luxation of the radius; he met with a case of the kind in dissection, and described it in his lectures. Ile found that the superior extremity of each radius had abandoned its natural situation, and was found situated behind the inferior extremity of the humerus, having passed this extremity an inch at least. This disposition being absolutely the same on each side of the body, there existed no difference between these two luxations, which were probably conge nital. It is also stated that Dupuytren had mentioned that about twenty or twenty-five years before he dissected the case now alluded to, he had seen a case nearly similar, but he was unwilling to speak positively on these cases, as the history was unknown, and acci dent or disease might have produced similar results.
Cruveilhier, in his very valuable work on Pathological Anatomy, quotes the above ob servations from Dupuytren's lectures, and seems to disagree entirely with the celebrated surgeon of theOtel-Dieu advancing it as his'opinion, that it would be much more na tural to suppose that the cases described by Dupuytren were not congenital, but rather very old luxations, a long time left unre duced.
It is very true that Dupuytren speaks with hesitation about the matter, as he appears to have met with but two eases, nor can any one speak with certainty on this subject, until ob servation on the living, and anatomical in vestigations, shall be combined to elucidate the matter ; but we think that already enough can be adduced to spew, that we have strong grounds for believing that such a congenital defect as luxation of the upper extremity of the radius backwards may be occasionally met with, and this is an opinion we think our selves authorised to advance, because of the facts and reasons we can adduce to support it.
In the Museum of the Royal College of Sur geons in Ireland, there is a specimen, which the writer considers to be one of congenital lux ation of the upper extremity of the left radius backwards; fig. 44 is a representation of it. The outer condyle of the humerus exists, but in front of it there is no rounded bead or eapitulum for the radius, or any trace of the usual convex articular surface ever having existed. The coronoid process and great sig moid cavity of the ulna are unusually large transversely, and stretch almost the whole way across the lower articular extremity of the humerus, which is entirely formed into one single trochlea wider than natural. The head of the radius, which seems never to have been adequately developed, is situated behind the plane of the outer condyle of the humerus. The tubercle of the radius is much enlarged, and leans against the lesser sigmoid cavity of the ulna, while the neck of the radius, directed somewhat backward, is twice its natural length, and instead of reaching merely to the level of the lesser sigmoid cavity of the ulna, stretches as high up along the ulna as to reach near to the level of the summit of the olecranou pro cess, while the carpal extremities of the radius and ulna are, in their natural state, on an even line with each other.
There is scarcely any interosseous interval, the bones seem so closely connected with each other. Indeed, from the inspec tion of this preparation, we may justly infer that the fore-arm during life had remained much in a state of semifiexion on the arm, and of rigid pronation, and that the movement of supination was nearly impracticable. This defective formation, or atrophy of the capitu lurn and increased dere lopement of the trochlea of the humerus, which was so formed to ac commodate itself to the unusual breadth acquired by the coronoid process and the whole of the ulna, must not be con sidered unprecedented. We find, by referring to the beautiful work of Sandifort, (the Museum Anatomicum, table ciii. fig. 3,) a case similar to Tlie above delineated (fig. 45). In referring to it, the author states that the bones of the fore-arm wereanchylosed, That the form of the ca pitulum was lost, that the head of the radius was luxated completely backwards, and that the ulna alone remained in articulation with the hu the parallelism between these two cases will be still more fully seen, when, speaking of the lower articular extre mity of the humerus, we find that he says," Figura ergo capi tul i periit.Rotula unica, sed major forma tur;" and of the ulna, " insignem acquisivit am plitudinem et totam infe-, riorem ossis humeri par-` tern admittere potuit." In examining very lately the splendid col lection of morbid specimens contained in the Museum of Guy s Hospital, the writer's attention was caught by observing a pre paration of the radius and ulna, belonging, he is certain, to the same class of diseases now under consideration, namely, congenital luxations of the radius. In this preparation there is a very oblique relative position of the bones of the fore-arm to each other. While their carpal extremities are exactly upon a line with each other below, the neck of the radius is elongated upwards, and the head of this bone is displaced much backwards, and is situated behind and below the outer eondyle of the humerus, and reaches nearly to the summit of the olecranon. The coronoid pro cess and great sigmoid cavity of the ulna have acquired much breadth, and what is remark able in this case, and in which it differs from any other we have seen, is, that a process of caries had been going on in the articulation. Cruveilhier has given four drawings of two cases of complete luxation backward of the radius, which he however does not consider to be congenital. Nor is it in our power abso lutely to prove that they are specimens of congenital luxations backwards, although we feel persuaded that all the cases we have re ferred to, these inclusive, are very curious specimens of this congenital deformity of the radio-humeral articulation.