US 2443363 A
Description (OCR text may contain errors)
June 15, 1948. K. TOWNSEND ET AL- 2,443,363
. BONE PLATE Filed A ril 13, 1942 a I fi r anei' z, .Zbzqnsend WGZEZZWENTORS Patented June 15, 1948 BONE PLATE? Kenneth Townsend and iCharlesrw-nGilfillama-g Hollywood, Calif.
Application April 13, 194258crialfNoi438i838 2 Glaimsa (Cl. 1284-9929 Our invention relates to the art of bone setting, and-*has among its obj-eets and advantages -s.
theprovisionM an-improved 'b'o'ne plate.-"=--- In accompanying drawing Figure- 1 is a View of afi-"a'c'tl ired iemurillu's-fi trating ourinvention applied-thereto Figure 2 is a face.viewvofe-the-bone plate structure applied to the femur of Figure 1;
Figure -3 is a sectionalview -taken along the Figure 4 is a perspective-wievc-of-porti'ons of two overlapping bone plates.
Iii theembodiment seleeted iot illhstratingthe drawing illustrates two overlapping bone plates l secured to the fractured femur 42 by means of screws M. The plates I5 are identical. Our bone plate is made of austenitic (hardened by cold working) stainless steel. The non-corrosive alloy prefer-ably contains eight per cent of nickel and eighteen per cent of chromium. The bone plate is 20 cm. in length, 1.4 cm. in width and 0.4 cm. in thickness. A series of slots It for the screws I4 is provided along the longitudinal medial line of the plate, which slots are 1 cm. in length with widths slightly larger than the 6-32 or 6-20 machine screw. The slots are spaced 1 cm. apart.
The two marginal side edges of the plate are deformed to provide V-shaped contours l8 wherein the outside flanges 20 are considerably wider than the inside flanges 22 so as to bring the flanges 20 into bone engagement with the body of the plate spaced from the bone.
In operation, the plate may be cut at the operating table to the desired length. If necessary, the plate may then be molded or contoured to the bone contour through the aid of pliers. While an assistant approximates the fragments with bone-holding forceps, the plate is applied to the exposed bone, and holes (#36 drill) are drilled in the middle of the slots l6, through both cortices, and the screws inserted. The screws M are of the fluted type, which renders the screws self-tapping.
The longitudinal slots l6 are characterized by many advantages over the conventional round or countersunk screw holes. The fracture need not be in apposition when the plate is applied. The ends of the fracture may be more than one quarter inch apart. The screws are sunk to light contact with the plate, pressure is then applied above and below on the fractured member, the fracture thereby being accurately reduced. The screws are then tightened. After muscle tone has been restored postoperatively, the pull only 5.4% The =plate f isxtcorrugated longitudinally [to the":
contour 'ofi-ia :mo'difiedeMr-in crossrarsectionywhich allows maximum strength inia. plate of relatively thin auge metalsii The corrugated" cross section is of uch contourcasito iallowon-ly the -two outer" a flan es:.-.-to comexinanwntact with: .the 1 bone, thus havingrelativelysmall b'one contact;:.which allows tends to furthers reduce: thearlfra'ctured-r surfaces promoting quichenhealingn Plastermasts-areeune' nece-ssary,- light-suspension: or;traction-- beingused "A for a short-period, tor walkingcalipers:
new bone to form unclercthearbody of the plate: Tli'e corrugated contour ofrthetplate wheri, ap-
plied te th convexisurface of theszboneyatends to:
maintain the original longitudinal axis of the fractured bone fragments. The plate action prevents lateral stresses on the shafts of the screws used to hold the plate, which helps to prevent loosening of the screws. Figures 1 and 2 illustrate two stacked plates, such stacking being desirable in connection with femurs, large humeri and tibiae. For double fractures of the femur, tibia or humerus, i. e., where fractures involve the upper third and lower third of the bone, thereby producin a free fragment, the plates may be overlapped and staggered end-wise to maintain a continuous metal truss. In connection with conventional plates, this type of fracture necessitates two plates without continuous metal bridging. The corrugated contour allows the plates to be stacked or nested for additional strength as needed. Such stacking of the plates provides a leaf spring action, which counteracts sudden stresses in the fractured member, caused by sudden muscle contracture or spasm, falling of the patient, or undue early weight bearing of the patient. Because of the overlapping coaction of nested plates, one or more free fragments of bone may be completely bridged with a metal truss. The thin gauge of the plate allows it to be cut at the time of the operation, when the exact length has been decided upon. Thus many plates of diiferent lengths are not required as is necessary with the conventional bone plates.
' The plate is easily bent to the longitudinal contour of the bone, even to right angles, without danger of breaking the plate. This is done at the time of the operation with the field exposed.
The slots through which the screws l4 pass allow the muscle pull to more closely approximate the fracture surfaces. In connection with conventional plates, the cortex on the plate side is often held apart while the opposite cortex is closely approximated, thus permitting undue strain on the plate. Whether the plates are used singly or in nested relationship, the cross sectional end contour and the slotted feature function in the same manner. The combined strength of the two plates is greater than two individual plates because of the leaf spring action. The fluted end of the screw M has an eccentric point formation and the fluted formation extends a considerable distance longitudinally of the screw. Such a screw allows a smaller hole to be used in the bone with greater holding power, and with about forty percent greater tapping ease.
Without further elaboration, the foregoing will so fully illustrate our invention, that others may, by applying current knowledge, readily adapt the same for use under various conditions of service.
1. A combination brace for fractured bones comprising a plurality of comparatively thin elongated plates in laminated relation providing a leaf spring-like brace, each of said plates having the same shape in cross section providing nesting thereof, and each of said plates having a centrally disposed flat web with inverted V-shape flanges at the edges and with the outer legs of said V-shape flanges longer than the inner legs providing means spacing the centrally disposed Web from a plane across the outer edges of the outer legs of the flanges, said centrally disposed webs having spaced elongated centrally positioned screw receiving slots therein adapted to register with the plates nested with the ends aligned and also with the plates staggered.
2. A connecting plate for fractured bones comprising an elongated strip of material having spaced slots therein extending continuously throughout the length thereof, and in which the said strip, in cross section, comprises a flat intermediate area in which. the slots are positioned, with the sides of the strip at the edges of the flat area extending upwardly and then downwardly assuming V-shapes with the extreme edges positioned below the plane of the said flat area thereby spacing the flat area from a plane corresponding with the said extreme edges providing a springy gripping action of the said plate with a bone on which it may be secured by screws through the said slots.
CHARLES W. GILFILLAN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,018,452 Slaughter Feb. 27, 1912 1,025,008 Miner Apr. 30, 1912 1,105,105 Sherman July 28, 1914 2,133,859 Hawley Oct. 18, 1938 FOREIGN PATENTS Number Country Date 19,736 Great Britain Sept. 9, 1902 OTHER REFERENCES Bickhams Operative Surgery, 1924, vol. 2, pp. 362 and 369.