DESCRIPTION 
AND 
PRACTICAL DEMONSTRATION OF THE WORKING 
OF 
ROBERTS’ 
Improved Electro-Osteotome, 
NEW ELECTRICAL ILLUMINATING APPARATUS, 
AND A NEW FORM OF PORTABLE 
STORAGE BATTERY. 
by 
Milton Josiah Roberts, M. D., 
Professor of Orthopedic Surgery and Mechanical Therapeutics in 
the New York Post-Graduate Medical School and 
Hospital; Visiting Orthopedic Surgeon to the 
City Hospitals on Randall's Island. 
Reprinted from The New York Medical Monthly for October, 1886. 
New York : 
DE LEEUW, OPPENHEIMER & MYERS, PRINTERS,' 
108 and 110 DUANE STREET. 
1886. DESCRIPTION 
AND 
PRACTICAL DEMONSTRATION OF THE WORKING 
OF 
ROBERTS’ 
Improved Electro- Osteotome, 
NEW ELECTRICAL ILLUMINATING APPARATUS, 
AND A NEW FORM OF PORTABLE 
STORAGE BATTERY. 
BY / 
Milton Josiah Roberts, M. D./ 
Professor of Orthopedic Surgery and Mechanical Therapeutics in 
the New York Post-Graduate Medical School and 
Hospital j Visiting Orthopedic Surgeon to the 
City Hospitals on Randall's Island. 
Reprinted from The New York Medical Monthly for October, 1886. 
New York : N 
DE LEEUW, OPPENHEIMER & MYERS, PRINTERS, 
108 and 110 DUANE STREET. 
i886. DESCRIPTION 
AND PRACTICAL DEMONSTRATION 
OF THF. WORKING OF 
Roberts Improved Electro-Osteotome, 
NEW ELECTRICAL ILLUMINATING APPARATUS, 
AND A NEW FORM OF PORTABLE 
STORAGE BATTERY. 
IN whatever direction we extend observation and research so as 
to harmonize facts, it always happens that the information 
thus acquired opens up an entirely new field for discovery. 
Hand in hand with the successive glimpses thus gained of new 
knowledge to be acquired comes the demand for better and more 
thoroughly elaborated instruments of scientific research. It thus 
happens that in many instances discovery comes to depend upon 
invention. The reverse of this statement is also true ; invention 
frequently depends upon discovery. There is, then, a reciprocal 
relationship existing between invention and discovery ; for, while 
freshly correlated facts, pointing out new truths of nature, serve 
as a basis or stimulus to invention, further progress in knowledge 
may, at any time, become extremely slow or absolutely impossible 
without invention, or, in other words, until some one makes a new 
application of correlated facts. Discovery and invention, then, 
are the handmaids of science. There is probably no stronger ally 
to the acquisition of verifiable knowledge than new and improved 
instruments. 
The range of usefulness of our senses may be enormously in- 
creased by the invention of a new instrument or the improvement 
of an old one. The electrical telephone, the compound micro- 
scope, the telescope, the spectroscope, the microphone, the laryn- 
goscope, the stethoscope, the aesthesiometer, the thermometer, the 
ophthalmoscope, and many other instruments might be named in 
support of this statement. 
Instruments not only extend the range of our senses so that 
we can see, hear and feel what could not be seen, heard or felt 
without them, but they are also of the greatest possible aid in de- 4 
termining the limitations of our sensory impressions, or, in other 
words, reducing to definite terms differences or similarities which 
we perceive by our unaided senses, or by the use of instruments. 
Under this head might be mentioned all instruments of precision, 
so called, such as, for instance, linear mensuration instruments, 
which enable us to determine the distance between two points ; 
the difference in length between two limbs ; or again such an 
instrument as will enable us to determine in definite terms the 
difference in the temperature of various parts of the body ; or 
still again an.instrument which will enable us to determine in de- 
grees the extent of bodily deformities.* ' 
New applications of force or development of increased power 
may result from the invention of new instruments. In illustra- 
tion of this fact the hydraulic press may be cited, by the aid of 
which enormous powrer was developed, which, when applied to 
the compression of gases, resulted in the discovery of a new law, 
the law of the compressibility of gases. In surgery the osteo- 
clast is an instrument by the use of which the surgeon is enabled 
to exert great power—sufficient to fracture a bone at a given 
point for the correction of deformity. 
Then, again, the invention of a new instrument often facilitates 
the execution of work so enormously that new and greater under- 
takings not only become possible, but are made absolutely practi- 
cable. The locomotive engine and the steamship furnish us with 
facilities for travel which enable one to complete with ease and 
comfort a journey in the course of a few days or weeks which 
prior to their introduction would have required many weeks or 
months. 
Were I to detail all the ways in which invention aids discovery 
and promotes the acquisition of knowledge, I would have to write 
a very large volume. My only object in referring to the subject 
on the present occasion is to call attention to the proper relation- 
ship which exists between the acquisition of verifiable knowledge 
and invention. I do this because I have so frequently heard it re- 
marked by medical gentlemen, that though they were continually 
using instruments they found no occasion for the invention or 
elaboration of others than those in general use ; that whatever 
work could be done at all could be as well done with the existing 
armamentarium' as by the use of any of the so-called improve- 
* I have called attention to three instruments of precision, designed with special refer- 
ence to diastrophometric (Sia<7Tpo<|>i), a distortion, and p.erpoi', a measure) observations, in a 
recent paper entitled, “Anatomical Geometry and Toponomy ; an Introduction to the 
Scientific Study of Deformities, with a description of New Mathematical Instruments.” 
Read before the Medical Society of the State of New York, February 3, 1885. 5 
merits ; and furthermore that the only motive which they believed 
most inventors had was to devise or modify some instrument in 
order that it might bear their name. 
This is indeed a poor apology for making no endeavor to ad- 
vance knowledge and increase our resources for the relief of hu- 
man suffering by invention. The indications for invention in med- 
icine are nowhere more clearly seen than in the department of 
bone surgery. We are still almost wholly dependent upon hand 
power and hand implements for cutting bone, while in other me- 
chanical arts a great variety of machines have been invented for 
working hard materials of every kind. The surgeon of the pres- 
ent day who, in the face of a full knowledge of the existence 
and daily advantageous use in the arts of varied forms of ma- 
chines impelled by other force than muscular power, and de- 
signed for the rapid and accurate cutting of hard substances un- 
der all sorts of conditions, continues to execute his conservative 
operations upon bone by the use of drills, trephines, saws and 
chisels, all exclusively worked by his own muscular power, would, 
from a machinal standpoint, seem to be almost comparable to the 
primitive man who, looking with superstitious awe upon the forces 
of nature as manifested by the lifeless activity about him, con- 
tinued to propel his boat with poles and oars for ages before 
he dared venture to utilize the force of the wind, by spreading a 
sheet before it, to waft his boat along ; who ground his grain be- 
tween stones and turned his mill by muscular effort for ages 
more before he overcame his timidity sufficiently to utilize for 
this purpose the force of the flowing water in the babbling brook 
as it rushed on its way to join some mighty river. 
There are, however, some extenuating statements to be made 
other than the necessary expenditure of time and money in ex- 
planation of the tardiness of invention, by surgeons, of machines 
impelled by other forces than their own muscular effort, and de- 
signed for operating on the bones of living human beings. In 
the first place, there is a mistaken tendency on the part of recog- 
nized medical authorities to represent our knowledge as assuming 
an approximately complete character, forgetting as has already 
been stated, that each new correlation of facts opens up new fields 
for investigation. Then, again, the surgeon rarely begins his work 
with a thorough knowledge of mechanics, and this deficiency not 
being made up in after years, he is necessarily slow in taking the 
first step towards invention, viz., in the recognition of the need 
of improvement; and he is still slower in taking the second step, 
which it is essential he should take before he even makes the first 6 
attempt at improvement, viz., that the bringing of this about is a 
feasible undertaking. 
If we for a moment compare our surgical armamentarium for 
operating in soft parts with that in general use for operating in 
hard tissues the disparity between the two is at once strikingly 
manifest. It is to describe and make a demonstration of the 
practical working of an instrument which, in my judgment, will 
help to make good this disparity that I have come before you to- 
night. The instrument referred to is what I have called the elec- 
tro-osteotome. The attention of the medical profession was first 
publicly directed to this instrument by a short communication to 
the North-Western Medical and Surgical Society of this city, Oc- 
tober 17, 1883.* 
The instrument as originally described (see Fig. 1., which rep- 
resents it as it ap- 
pears when sus- 
pended and 
grasped by the 
hand of the sur- 
geon ready for ac- 
tion) consists of a 
small electro-mo- 
tor, supplied with 
electricity through 
insulated wires, 
from a powerful 
ten-cell primary 
zinc carbon bat- 
tery, and carrying a 
circular saw that 
revolves in a plane 
parallel with that 
of the central shaft. 
A hollow cylinder 
with a collar-like 
base is firmly 
screwed to the 
end plate of the 
motor. Upon this 
a soft rubber hand-piece, fashioned like that of a carpenter’s 
chisel, is slipped and fastened in position, forming the handle of 
Fig. 1. 
* The Electro-osteotome ; a newjnstrument for the performance of the operation of 
osteotomy, and a New Form of Retractor. New York Medical Record, October 27, 1883. 7 
the instrument, and enabling the surgeon to control it when oper- 
ating. The central shaft of the motor is continuous through the 
hollow cylinder. At its distal end a right-angle miter-gearing 
connects it with the saw-bearing point. A metal shield guards 
the proximal aspect of the serrated blade. Shields are provided 
for each size of saw. Four sizes of circular saws, viz.: 32 (i]/\ 
inch), 41 (1 inch), 51 (2 inches), and 63 (2*4 inches) millime- 
ters in diameter were originally provided. 
Upon the plate opposite the end of the motor to which the 
hand-piece is attached are two binding-posts, which receive the 
ends of the insulated wires connecting the instrument with the 
battery. 
When using the electro-osteotome it is suspended by a solid 
rubber cord, six or seven millimeters in diameter, from the cross- 
bar of an adjustable crane screwed to the edge of the operating 
table. In this way all weight is removed from the hand of the 
surgeon, leaving the instrument as thoroughly at his command 
as if it were a delicate probe. 
In order to protect the soft parts when operating, a protecting 
retractor of the form 
shown in Fig. 2 was em- 
ployed. Two such instru- 
ments as are here repre- 
sented form a pair. They 
are introduced one at a 
time through the linear 
incision in the soft parts, 
carried down to the bone and passed around it much after the 
fashion of applying obstetric forceps. When in position they are 
pressed apart, so as to make room for the circular blade of the os- 
teotome. By their use there is no possibility of injuring any of 
the soft parts while operating. The retractor here illustrated is 
provided with a double curve at each end, one large, the other 
small, so as to adapt it to large and small bones. 
This was my invention as originally brought to the notice of 
the profession in October, 1883. In it I found myself the pos- 
sessor of a machine that enabled me to make cross, oblique and 
linear sections of bone with exceeding ease, astonishing rapidity 
and great accuracy as to direction and extent of cut. 
But its range of action was too narrow. Already I could see 
wider fields of usefulness pending its further elaboration and de- 
velopment. And now for the improvements which have been 
made up to the present time. 
Fio. 2. 8 
By reference to Fig. 1, it will be seen that the motor is en- 
tirely exposed. I soon learned that this was a source of peril to 
the operator ; for, while intently watching the section of bone 
which was being made, if perchance he brought his head or face 
Fig. 3. 
close to the instrument, he was in very great danger of losing part 
of his beard or the hair of his head by having it caught in the 
rapidly revolving armature of the motor. I soon came to realize 9 
the importance of overcoming this objection ; for on three oc- 
casions while operating I lost a goodly portion of the beard on the 
left side of my face. The objection referred to was first over- 
come by placing a thin and narrow ferrule of hard rubber over 
each end of the motor, so as to entirely shut out from view the 
revolving armature. Subsequently these were replaced by a sec- 
tion of large thin hard rubber tubing, which was passed over the 
motor, covering it entirely (see Fig. 3 on opposite page). 
Another objection which demanded immediate attention per- 
tained to- the guards used to cover the proximal aspect of the 
saws, the object of which was to pre- 
vent blood from being thrown into the 
face of the operator and to avoid con- 
tact with the rapidly revolving saw 
blade. These guards originally con- 
sisted of two thin sheets of steel, sepa- 
rated by a narrow but thicker piece of 
metal at their proximal margin to which 
they were riveted (see Fig. 4, dotted 
line, which represents the position and 
width of the piece referred to). The 
guard passed over the saw and covered 
in nearly one-half of it. It was se- 
cured in position by means of a screw 
passed through its shank. The deep recess thus left between the 
two sides of the saw-guard served as a receptacle for blood and 
Fig. 4. 
Fig. 5 
bone dust. The difficulty of cleaning such a cavity can readily be 
appreciated. In fact, it was practically impossible to keep it sur- 10 
gically clean. To overcome this objection the saw-guard was 
made in two pieces (see Fig. 5, a and b). Only one of the sides 
of the saw-guard was riveted to the thick, narrow piece of metal 
on its proximal aspect (see Fig. 5, a). Three steady pins project- 
ing from the thick narrow piece of metal served to keep the two 
parts of the guards in proper relationship with each other while 
being handled. A screw passing through the shank of the guard 
into the hand-piece served to hold both of them in place when in 
use. This arrangement answered for a time, but ultimately one 
plate was removed entirely, and the other cut down to -a narrow 
strip. The thick piece of metal between the plates was entirely 
done away with. In its place a narrow rim was fixed at right an- 
gles to the side strip so as to pre- 
vent the centrifugal force of the 
revolving saw blade throwing blood 
into the face of the operator (see 
Fig. 6). Practical tests have shown 
this form of saw-guard very satis- 
factorily. 
A third objection to the instru- 
ment was the necessity of having an 
assistant to lower the battery plates 
into the fluid when it was desired 
to start the motor and to draw 
them out in order to stop it. To 
overcome this objection a simple 
switch was attached to the plate on 
the free end of the motor so that it could be opened and closed at 
pleasure. This increased the independence of the operator, for 
after the battery plates were lowered into the fluid the instrument 
was not set in motion until the desired moment, when by the use 
of his free hand (one being employed to grasp the handle of the 
motor) the operator closed the circuit by means of this switch, 
and the motor was set in motion. Upon completing a section 
of bone, the operator, without waiting for the battery plates to be 
withdrawn from the fluid, can open the circuit by means of the 
switch and stop the instrument. These improvements added 
greatly to the ease and facility of using the osteotome. 
Ambitious to widen the range of usefulness of my instrument 
I determined to so alter it that I would be able to use drills, burrs 
and trephines as well as circular saws. To this end the circular 
saw mountings were unscrewed from the free extremity of the 
hand-piece, exposing the beveled gear on the extreme end of the 
Fig. 6. 11 
extended shaft of the motor. I devised and adapted a head-piece 
provided with a clutch to fit into the beveled gear when it was 
secured in position on the end of the hand-piece (see Fig. 7). 
Tests with 
this head- 
piece proved 
conclusively 
that drills and 
trephines could be driven through bone with great ease and ra- 
pidity. An ordinary trephine, one-half of an inch in diameter, of 
pattern shown in Fig. 8, was adapted to my instrument. With it 
I was enabled to remove a button of bone from the skull in eight 
seconds, the thickness of the bone at the point of operation being 
a full quarter of an inch. The curves and teeth in these tre- 
phines are filed by hand, and are therefore not very regular. The 
consequence was that though bone wTas readily cut with it the in- 
strument did not work as smoothly as was desirable. I therefore 
had one constructed of the pattern shown in Fig. 9, which is a 
Fig. 7. 
very great improvement on the old one. The sides of this tre- 
phine are perfectly parallel, and the teeth all slant in one direc- 
tion. With an instrument of this pattern, of an inch in diame- 
ter, I removed a button of bone in five seconds, the skull at the 
point of operation being fully as thick as above stated. The pas- 
sage of the trephine through the bone is accomplished with such 
ease that the position of the cutting edge can be accurately esti- 
mated by the operator. In propelling a trephine by muscular 
power so much force is required to be exerted by the operator 
that tactile sensibility is practically annulled. 
All this was very satisfactory, but in operations requiring the 
use of both circular saws and drills, I found myself seriously em- 
barrassed in making the necessary changes incident to the alter- 
nate use of these instruments. The time consumed in making 
these changes almost precluded the use of circular saws and drills 
in the same operation. It was necessary to remove six small 
screws to rid the instrument of the circular saw attachment, and 
Fig. 8. 
Fig. 9. 12 
to introduce four small screws to secure the attachment of the 
head-piece for carrying the drills. The embarrassment expe- 
rienced in consequence of this defect in the osteotome led to my 
elaborating interchangeable head-pieces which could be alter- 
nately screwed to the end of the shaft of the instrument. See 
Figs, io and n, which represent the two views of the circular saw 
head-piece, and Fig. 12, which represents the head-piece for car- 
rying the drills, 
trephines a n d 
burrs. The 
dotted lines in 
Fig. 1 o represent 
the position of 
the improved 
saw-guard illus- 
trated in Fig. 6. 
The dotted lines 
in Fig. 11 and 
Fig. 12 represent 
the end of the 
hand-piece with 
h e projecting 
beveled gear on the end shaft of the motor which 
passes through the hand-piece. In Fig. 11 there is 
a dotted line indicating the blade of the circular saw. 
Their construction is apparent from an examination of 
Fig. io. 
Fid. i1. 
the cuts. Six sizes of circular saws, ranging from 
one to three inches in diameter, are now provided 
for the instrument, instead of four, the former number. 
Finally, the motor is provided with a small electric 
light mounted on a pedestal, which is screwed into the 
edge of the end plate to which the hand-piece is at- 
tached (see Fig. 3). Behind the lamp is a reflector, 
which projects the rays of light directly upon the site of opera- 
tion. This addition to the instrument was found desirable on 
account of insufficient light for operations late in the day. When 
Fig. 12. 13 
it is desired to use the light all that is necessary is to give a half- 
turn to a little thumb-screw indicated at a. Two cells of the bat- 
tery are reserved for lighting purposes, and are connected with 
the lamp by independent insulated wires. The circuits for the 
lamp and the motor being entirely independent, either one alone 
or both at a time can be brought 
into use as desired. A very in- 
genious electric light has been de- 
vised by my friend, Dr. William 
C. Jarvis (see Fig. 13). It was 
especially designed for laryngo- 
logical work, being attached to an 
ordinary head mirror. I think, 
however, it is well adapted for 
general lighting purposes. 
The form of retractor origi- 
nally used (see Fig. 2) had several 
objections, the most prominent of 
which was that of being sharp at 
both ends. In placing them in position the operator was likely 
to cut his hand unless he exercised unusual care. Fig. 14 shows 
the different forms of protecting retractors, which 1 now use ; 
Fig. 13. 
Fig. 14. 
a and b, Fig. 14, represent two pairs of retractors of different 
curves, one designed for large and the other for small bones. 14 
The form of retractors shown at c, d, e and / are used singly. It 
will be seen that they are provided with a longer blade, the curv- 
atures being adapted to the different sizes of circular saws. They 
are introduced in precisely the same manner as described for the 
retractors shown in Fig. 3. 
In conclusion I wish briefly to call your attention to a new 
form of storage battery. There is nothing novel in the construc- 
tion of the storage cells ; the novelty is simply in the form of the 
battery (see Fig. 15 and Fig. 3). In Fig. 3 the battery is repre- 
Fig. 15. 
sented as it appears when in use. It contains twelve cells, all of 
which are so connected that they can be brought into the circuit 
for driving the motor. Two of the cells, however, are connected 
independently, and are designed to be used for lighting purposes. 
By means of the switch, however, which is connected with the 
motor circuit, the two cells ordinarily used for the lamp circuit 
can be cut out of the lamp circuit and brought into play for driv- 
ing the motor. The switch-board is provided with two levers, by 
means of which in case a single cell in the battery is at fault it can 
be readily picked out from the others. As shown in Fig. 15, the 
cells of the battery can be exposed for inspection by the simple 
turn of a key. 
Before closing I wish to say that I look upon the electro-osteo- 
tome, even in its present state of development, as making it feasi- 15 
ble to perform successfully several new operations in bone sur- 
gery, which with the existing armamentarium it is not practicable 
to undertake. New operations are not only rendered practicable 
by using the electro-osteotome instead of the ordinary hand in- 
strument, but in my judgment the vast majority of operations 
that are now performed upon bones can be executed with it, not 
only with greater dispatch and precision, but with far less shock 
to the patient and consequent risk of life. 
io5 Madison Avenue, New York.