There is at this moment in the Richmond Hospital a young woman who met with this oblique fracture of the external condyle of the humerus near the elbow, when she was only five years of age. The outer condyle and capitulum of the humerus were detached ob liquely from the shaft of the bone and thrown backwards, carrying with them the head and upper extremity of the radius ; she now has very good use of her arm, but in consequence of the accident much deformity exists, parti cularly when she extends the fore-arm. The obtuse angle salient internally, which the fore arm forms with the arm in the natural state when it is fully extended, and the hand supi natcd, does not exist. On the contrary, in this case the salient angle is external, and corres ponds to the outer condyle and head of the radius, and the retiring angle is placed inter nally. (See Jig. 40.) The internal condyle of the humerus is fre quently broken obliquely from the body of the bone, and the symptoms by which the accident is known are the following : when the fore-arm is extended on the arm, the ulna projects be hind the humerus; the lower end of the hume rus, too, advances on the ulna, so that it can be easily felt on the anterior part of the joint ; on flexing the fore-arm on the arm, the ulna resumes its usual position ; by grasping the condyles and bending and extending the fore arm, a crepitus is perceived at the internal con dyle: this accident usually occurs in youth, although it may be seen in those advanced in life. It is an injury very likely to be mis taken for a dislocation.
2. Fractures which engage the upper extre mity of the bones of the fore-arm are chiefly confined to the ulna, for the radius very seldom suffers. Sometimes the olecranon process at the ulna is broken off, and occasionally a frac ture of the coronoid process occurs, the con sequences of which last accident are sometimes very serious. Sir A. Cooper gives us the fol lowing history: "A gentleman came to London for the opinion of different surgeons upon an injury he had received in his elbow. Ile had fallen on his hand whilst in the act of running, and on rising lie found his elbow incapable of being bent, nor could he entirely extend it ; he applied to his surgeon in the country, who upon examination found that the ulna pro jected backwards when the arm was ex tcnded,but it was without much difficulty drawn forwards and bent, and the deformity was then removed. It was concluded that the coronoid process was detached from the ulna, and that thus during extension the ulna slipped back behind the inner condyle of the humerus." A preparation of an accident, supposed to be similar, is preserved in the Museum of St. Thomas's Hospital ; the coronoid process, which had been broken off within the joint, had united by ligament only, so as to move readily upon the ulna, and thus alter the sigmoid cavity of the ulna so much as to allow in extension that bone to glide backwards upon the condyles of the humerus.
Fracture of the olecranon.—This process of the ulna is not unfrequently broken off; and the accident is attended by symptoms which render the injury so evident that the nature of the case can hardly be mistaken. Pain is felt at the back of the elbow, and a soft swelling is soon produced there, through which the surgeon's finger readily sinks into the joint ; the olecranon can be felt in a detached piece elevated sometimes to half an inch and some times to two inches above the portion of the ulna from which it has been broken. This elevated portion of bone moves readily from side to side, but it is with great difficulty drawn downwards ; if the arm be Kent, the separation between the ulna and olecranon be conies much greater.
The patient has scarcely any power to extend the fore-arm, and the attempt produces very considerable pain, but he bends it with facility, and if the limb be left undisturbed it is prone to remain in the semiflexed position. For se veral days after the injury has been sustained, much swelling of the elbow is produced, there is an appearance of ecchymosis to a consider able extent, and an effusion of fluid into the joint ensues; but the extent to which these symptoms proceed depends upon the violence which produced the accident. The rotation of the radius upon the ulna is still preserved ; no erepitus is felt unless the separation of the bone is extremely slight. Fractures of the upper extremity of the ulna are sometimes very com plicated. Thus Mr. Samuel Cooper informs as that there is a preparation in the Museum of the London University, illustrating a case in which the ulna is broken at the elbow, the posterior fragment being displaced backwards by the action of the triceps ; the coronoid process is broken off; the upper head of the radius is also dislocated from the lesser sigmoid cavity of the ulna, and drawn upwards by the action of the biceps.
Luxations.—The bones of dui fore-arm are liable to a great variety of lusations at the elbow-joint ; the following arrangement will pro bably be found to comprehend most of those accidents as yet known and described.
1. Luxations of both bones backwards; 2. Luxations of both bones laterally, complete and incomplete ; 3. Luxations of both bones laterally and posteriorly ; 4. Luxation of the ulna alone backwards; 5. Luxation of the radius alone forward ; 6. Luxation of the ra dius externally and superiorly ; 7. Complete luxation of the radius backwards ; 8. Sub-lux ation of the radius backward ; 9. Congenital luxation of the radius.