A female, mt. 47, was admitted into the Richmond Hospital, under the care of the late Dr. Macdowell, for an injury of the hu merus, the result of a fall upon the shoulder. The case has been merely entered in the Hospital Case-Book, " a fracture of the humerus." Five years afterwards, the wo man was admitted into the same hospital, under the care of Mr. Adams, for another in jury, a fracture of the thigh, of which she died. Post mortenz, the shoulder was care fully examined. The arm was slightly short ened. The contour of the shoulder was not as full nor as round as that of its fellow, and the acromion process was more prominent than natural. Upon opening the capsular ligament, the head of the humerus was found to have been driven into the cancellated tis sue of the shaft, between the tuberosities, so deeply as to be below the level of the summit of the great tubercle ; this process had been split and displaced outwards; it formed an ob tuse angle with the outer surface of the shaft of the bone. The distance to which the su perior fragments bad penetrated into the shaft is well seen in the wood-cut (fig. 432.) Nelaton and Smith* have alluded to cases pf intra-capsular fractures of the head of the humerus, in which the detached head of the bone became inverted on itself, and was thus impacted into the shaft of the humerus. Nela ton observes :—" Dr. Dubled showed me a specimen, in which the cap which the summit of the head of the humerus forms had been broken from the shaft, and afterwards in yerted on itself, so that the broken surface of the upper fragments looked upwards and in wards, while the smooth polished articular part looked downwards, and in this position was buried into the shaft or inferior fragment. Notwithstanding this displacement, consoli dation had taken place." The superior frag ment was enveloped by stalactiform produc tions, which had sprung up from the shaft of the humerus.
In the year 1843, Dr. Robert Smith laid before a meeting of the Pathological Society of Dublin, a remarkable specimen of a frac ture of the neck of the humerus, in which the head of this bone was driven into the shaft, splitting asunder the bone in the situation of the tuberosities. The subject of the observa tion was a woman, mt. 40, who, many years before her death, had met with the accident. On proceeding to make the post-mortem ex amination of this case, it was remarked that the acromion process was prominent ; the del toid flattened ; the arm was shortened ; the glenoid cavity could not be felt ; the shaft of the humerus was drawn upwards and invvards, so as to be almost in contact with the cora coid process ; the motions of the joint were limited ; and the capsular muscles atrophied.
Dissection.— When the soft parts were re moved, and the capsular ligament was opened, the traces of a fracture having long ago passed through the anatomical neck of the humerus were obvious. The head of the humerus was solidly united to the shart. But, upon ex
amining further, what struck Dr. Smith as very remarkable was, that the head of the humerus was found reversed, or turned up side down, in the articulation ; or, in other words, the fractured surface was turned up wards towards the glenoid cavity', and the cartilaginous articulating surface turned down wards, as in Nelaton's case, towards the shaft. The only explanation of this circumstance which can be given is, that the. head of the bone, at the time of the accident, had been completely separated from the shaft by a frac ture through the anatomical neck ; that thus rendered free in the interior of the joint, the head of the bone became inverted on itself, and was thus subsequently driven into the cancellated structure, between the tubercles.
It appears that in the Museum of the Col lege of Surgeons of Dublin, a third specimen of th's complete inversion of the upper frag ment of the brok' n humerus is to be found.* 2. Extra-capsular fracture through the tuber cies. —The fracture may be extra-capsular ; passing through the tuberosities beneath the anatomical neck of the humerus, yet above the line of the junction of the epiphysis, with the shaft of the bone.
This fracture is usually the consequence of severe falls on the outside of the shoulder ; it may occur at all ages, but is most frequently met with in elderly persons. The line of the lesion may be transverse, but usually the bone is broken into many fragments. There is some shortening of the arm, but very little if any transverse displacement of the bony fragments The long tendon of the biceps, in front, and the strong fibres proceeding, from the bony attachment of the capsular ligament and capsular muscles, will retain the fragments in their place. The shortening is the result of the mutual impaction into each other of the super:or and inferior fragments. As the fracture thus generally exists without any very obvious displacement of the fragments, and as it is usually accompanied by much swell ing of the shoulder joint, the diagnosis may be very obscure.
Symptoms.— The patient will coniplain of severe pain in the shoulder, which is much increased by the least pressure, or by commu nicating any movement whatever to the arm ; and Ile cannot, by any voluntary effort of the muscles of the injured arm, elevate it ; on making a methodical examination soon after the accident has occurred, crepitus can be elicited. As to the degree of power which the patient possesses of moving his arm in these cases, some variety may be noticed, par ticularly if some day s have elapsed since the receipt of the injury.
The following case of fracture through the tuberosities of the humerus was very recently under observation at the Richmond Hospital, and may be here adduced, to show the diffi culty that may occur in making our diagnosis if the case is not seen soon after the occur rence of the accident.