ON A CASE 
OP 
HUMAN CONGENITAL MALFORMATION 
(Perobrachia), 
By HARRISON ALLEN, M.D., 
Prof, of Physiology University of Penn'a. 
[Proceedings American Philosophical Society, Vol. XXI, 1883, p. 4.13.) Dec. 21,1883.] 
413 
[Allen. 
On a Case of Human Congenital Malformation. By Harrison Allen, M. D. 
{Read before the American Philosophical Society, December 21, 18S2.) 
I desire to place upon record the facts in the case of a man born with 
rudiments of the superior extremities. Similar cases, it is true, have been 
recorded, and in a sense, this history lacks the claim of a positive contri- 
bution to knowledge. But it is well to record each example of unusual 
conformation, when novel facts pertaining to the adult state, to habit and 
to acquired deformity, can be demonstrated.* 
The case is one of a group denominated Perobrachia and is embraced 
in the following account: 
John E. Casey, aged sixty-four years, one of a family of seven well- 
formed children of healthy parentage was examined Nov., 188:3. The 
subject was four feet and seven inches in height. In the place of the left 
superior extremity a small pedunculated lobule one inch in length was 
suspended from the axilla a short distance behind the group of axillary 
hairs. This lobule retained a slender rod of bone which could easily be 
determined, and which doubtless was homologous with the bones of the 
normal left superior extremity. 
The right superior extremity was a small unidigitate member, bent at 
the middle so as to resemble a letter L and when at rest so disposed to 
the trunk as to correspond in length to the side of the thorax. 
The humerus was apparently dislocated upon the dorsum of the scapula 
on an outward extension of the glenoid cavity, and the bone was thus 
held in an exceptional relation to the scapula. The shaft of the humerus 
was bent at the distal third so as to present a convexity outward and 
yielded a short distance above the elbow to its lateral side, a small spine 
which while detected, with ease, did not form an elevation of the skin. 
The position of the olecranon and that of the elbow-joint could be read- 
ily determined. The remaining portion of the extremity represented ele 
ments in a single axis excepting at the terminal phalanx. Within this 
axis the hones of the forearm, of the metacarpus, and the two phalanges 
of one digit could be identified. 
The bones of the left shoulder-girdle were small but complete. 
Of the right elements it was found that those of the shoulder-girdle were 
unusually well developed. Both scapulas were elevated, and the clavicles 
obliquely placed, the sternal ends determining the lowest, and the eleva- 
•A somewhat similar specimen to the one described is reported by Otto 
(Monstru. Tab. xvi, figs. 7, 8, p. 138). The condition was symmetrical, the radius 
absent, and the single linger was identified as the fifth, since the ulnar nerve 
passed to it. The subject was an unviable female foetus, of the seventh month. 
Forster (Mlssbildungen) refers to several cases; references imperfect and not 
reliable. See also Anger (Nouveaux Elements de l’Anat. Chirurgicale, 573, 574). Allen. 
414 
[Dec. 21, 
tion of the scapulas (through the agency ot the trapezii, rhomboidei and 
elevators of the angle of the highest levels. 
Fig. 1. 
Fi®. 1 —Front view of a case of Perobrachia, showing the rudiment of the left 
upper extremity, and the undigitable right upper extremity. 1883.| 
415 
(Allen. 
Fig. 2. 
Fio. 2. Hack view of a case of Perobrachia, showing tlie rudiment of the left 
upper extremity, the disproportion between the scapulas, the deviation of the 
vertebral column, and the relaxation of the muscles of the buttock. 416 
Allen.] 
[Dec. 21, 
The measurements were as follows : 
Left Side. 
The length of the spine of scapula 5".3'" 
Greatest length of scapula 5''.6"' 
Distance from angle to tip of acromion 6".G!" 
Length of clavicle 3".6'" 
Right Side. 
The length of spine of scapula 5". 6"' 
Greatest length of scapula 5". 6"' 
Distance from angle to coracoid process 6//.9,,/ 
Length of clavicle G/,.0/// 
Length of humerus 10".O'" 
Distance from proximal border of exostosis to the 
elbow 4,/.0'" 
Distance from elbow joint to wrist-joint 2".O'" 
Length of first phalanx 
Length of second phalanx 07/. 1>,,/ 
The motions of the left extremity were confined to upward traction of 
the scapula as already mentioned, and backward traction of the lobule, 
the latter apparently through the agency of a pannicular muscular sheet. 
The motions of the right extremity embraced the powerful effects of the 
tractors of the scapula, and the flexors and extensors of the forearm. The 
shoulder-joint being anchylosed, the extrinsic muscle of the shoulder- 
girdle, the trapezius, the serratus magnus, the levator anguli scapula, and 
the serratus magnus, and possibly the sub-clavius, were mainly effective in 
moving the extremity. The pectoralis major was also powerful. Abduc- 
tion of the arm (probably rhomboidal) was associated with marked median 
(i. e. vertebral) deviation of the scapula ; adduction (pectoral) with equally 
marked lateral deviation. Abduction was limited, the arm not being 
carried out from the trunk beyond an angle of 45°. Adduction on the 
other hand was powerful and complete. 
The motion of the elbow permitted all the portion of the limb placed 
distally to the joint to be moderately extended. At the end of extension 
the elbow was distinctly angulated. At the end of flexion the forearm 
and hand are doubled up to the median side of the humerus. The termi- 
nal phalanx when the limb was at rest was strongly adducted, and a re- 
entering angle was formed between the median border of the first and the 
second phalanx. When the limb was flexed this angle was direcled up- 
ward and outward; but when the limb was extended it was directed out- 
ward. From this circumstance it may be said that the flexion and ex- 
tension at the elbow-joint was accompanied with sub-rotation. 
Together with the primal or congenital defects numerous acquired ones 
were present. The most conspicuous of these was a lateral deviation of 
the vertebral column to the right, the result probably, of the unantagon- 
ized traction of the muscles of the right side, and in part also to imperfect 1883 ] 
417 
[Allen 
ossification in the hones comprising the column. As a result of this devia- 
tion the scapula of the left side was displaced and the angle lodged behind 
the upper border of,the ilium. It thus appeared to be wedged down in the 
pelvis. A second acquired defect was found in the muscles of the buttock 
and the back of the thigh. The gluteus maximus of each side was feeble, 
and in no position of the body became tense. The entire labor of holding 
the trunk erect wTas thrown upon the hamstrings which, particularly the 
biceps flexor, was on each side of enormous size. 
Under the head of habith, the result of the defects described, may be in- 
cluded the manner by which the subject could attend to acts of the toilet 
and to the handling of tools, etc. Like most persons whose arms are either 
defective or absent, the toes and lips become highly functionalized, and 
the methods of their use are in this case no different from others recorded. 
Casey has supported himself, honorably, as a farm laborer and peddler; 
and has, for a period of years extending beyond the average longevity, 
preserved good health and character. For many years he was em- 
ployed as a driver of oxen. The guiding staff was held by the powerful 
pectoral muscles between the arm and the chest. A nail can be driven 
with accuracy and force by placing the handle of the heavy hammer be- 
tween the arm and the chest wall, holding the nail upright between the 
first and second toe of the left foot, and while standing erect on the loot 
of the opposite side, he flexes the left leg at the knee. In this position the 
body is supposed to be standing on the right leg, the left leg flexed and the 
left foot raised upon a bench or stool. The motion of striking the blow 
is secured by throwing the trunk suddenly forward from a position of back- 
ward traction or extension ; the shoulder-muscle being occupied keeping 
the hammer in position between the arm and the trunk. The act of 
writing is accomplished by holding the pen between the flexed arm and 
the side of the head, the lips being used in guiding the pen. Other acts 
such as dressing, shaving, etc , are possible. 
Remarks.—The modern method of studying congenital defects, as for- 
mulated by Meckel and St. Hiliare, father and son, is based upon the 
assumption that every embryo exhibiting an aberrant disposition of parts 
is an example of perverted or arrested development. The school of St. 
Hiliare accepts the conclusions that such perversions and arrests are exhi- 
bitions of and reversions to the characteristics of lower animals.* 
While these statements cannot be in all respects controverted, an error 
is prevalent as to the systematic value of aberrant structures. An exam- 
* “These (specimens) compose organic entities perfectly characteristic, amen- 
able to law hut placed in another kind of regular arrangement. When mon- 
sters are thus rigorously determined, I propose to group them after the zoologi- 
cal method and to determine for them genera and species.’’ (Etienne Geoffroy 
St. Hiliare, Ann. Sc. Nat. xiv, 1828,108.) 
“An animal exhibiting anomaly which is essentially the same in structure as 
a part normally developed in a lower form, may be said to be degraded, and 
thus to have taken on the characters of creatures lower in the scale than itself.” 
(Isodore Geoffroy St. Hiliare, Propositions, etc., 6i.) 
PItOC. AMEK. PHILOS. SOC. XXI. 115 3a. PRINTED APRIL 8, 1884. 418 
[Jan. 18, 
pie in the form above described, of a solidungulate extremity would sug- 
gest to the evolutionist a comparison with the foot of the horse ; the single 
unguis, the nearly straight though multi articulate axis from the unguis 
to the elbow, the main lines of motion, are identical in the two instances. 
But it is equally like the wing of a bird, and an analogy might be instituted 
with that limb: the extreme degree of tiexion possible between the two main 
segments, the presence of two hones in the forearm, are the same in both. 
Such a method of comparison is no more conclusive than the likeness of 
clouds to camels and to whales. We can say with Polonius, such things 
are very like, and yet be no nearer in the end to a conclusion than in the 
beginning. The real comparison and only comparison which is profitable 
to make is with the general history of the superior extremity studied as 
a distinct subject, no matter what special form of limb may he differen- 
tiated in various animals. The presence of the exostosis upon the humerus 
is in this way comparable to other spinous outgrowths such as are seen in 
long slender shafts (as in the ribs of fish and of birds), and in many ex- 
amples of diseased and perverted action in the long hones of man. 
While such strictures are applicable to the various regions of the body, 
they cannot he made to apply to the subdivisions of a given anatomical 
system. The variations in the muscular system of man, for example, are 
often precise instances of reversion to the normal arrangement as met 
with in lower forms. In this way the study of minute variations in the 
shape of a muscle, or in the distribution of a nerve or a blood vessel, is 
more valuable for the purpose of the student of evolution than is the inves- 
tigation of monstrous deformations.