US2388482A - Surgical screw - Google Patents

Description

H. H. HAYNES SURGICAL SCREW Nov. 6, 1945.

Filed Jan. 16, 1945 Patented Nov. 6, 1945 UNITED. STATES PATENT OFFICE SURGICAL SCREW Herbert H. Haynes, Clarksburg, W. Va.

Application Jan!!! 16, 1943, Serial No. 472,649

2 Claims. (Cl. -140) This invention relates to surgical apparatus and has for its primary object to provide a simplified means for firmly securing skeletal splints, such as shown in my United States Patent #2,238,8'70, in position in an expeditious manner.

More specifically, it is an object of the invention to provide a skeletal'screw which is adapted to pierce the outer cortex of the bone, cross the medullary canal, and. imbed its point in the opposite cortex, without the necessity of using finders. flanged sleeves, etc.

Another object of the invention resides in the provision of a skeletal screw having drilling and self-tapping features, whereby the screw can be firmly anchored in the bone in a'single operation, thus reducing the time involved in applying the splint, which is of course a major factor.

A further object of the invention consists in providing a skeletal screw havim the foregoing features, and which is also so constructed as to provide for the discharge of the fine particles cut engaging portion 8 for use in rotating the shaft when the screw is to be applied to a bone.

Formed on the lower end ofshaft 5 is a drill portion I, the widest dimension of which is somewhat less than the diameter ofshaft 5, as shown in Figure 3. Spaced slightly above the drill I are four radial arms 8 separated by longitudinal grooves 9. The outer ends of the arms 8, are provided with threads III which are interrupted by the grooves 9; these threaded'sections serving as taps to cut threads in the bone to receive the continuous threads ll formed on theshaft 5 immediately above the thread-tapping porion.

The grooves 9 extenddownwardly below the tapping sections 8-8. and provide passages for the upward travel of the cuttings to prevent their entrance into the medullary canal, and also to prevent clogging of the screw; the grooves 9 are of sufficient length to receive the bone cuttings from the bone by the drill, thereby not only re- Figure 2 is an enlarged fragmentarysection.

one of the screws in through a bone and showing its final position.

Figure 3 is an enlarged elevational view of the lower portion of one of the screws.

Figure 4 is a view similar tol 'lgure 3, but taken at a 90. angle, and l Figures 5 and 6 are enlarged horizontal sectional views taken on line H and 8-6 respectively of Figure 3.

Referring to the drawing in more detail and particularly to Figure 1, the numerals I and 2 indicate the two sections of a broken bone which is to be set," and the numeral 3 indicates the splint blocks. These blocks, which form a part of the ambulatory splint described in the abovementioned patent, are firmly secured to the bone fragments I and 2 by means of the novel selftapping screws 4.

Each screw 4 comprises a shaft portion I on the upper end of which may be formed a tooland permit the exit of some of them, thereby leav. ing the tap threads Ill free to out clean and well defined threads in the bone structure.

The lower portions of the arms 8 are preferably tapered downwardly as indicated by the numeral H to facilitate movement of the screw into the bone.

The operation and advantages of the novel screw are believed to be apparent. After an incision is made in the flesh at the desired point the drill point is inserted and then rotated by an implement attached at the point 6. This rotation, with the desired pressure, causes the drill 'I to initiate an opening in the outer cortex of the bone, such opening being of slightly smaller diameter than theshaft 5. Continued rotation of the shaft causes the interrupted threads on the arms or tapping portion 8 to cut threads on the walls of the opening provided by the drill 1. The threads II onshaft 5 are then readily received in the opening upon continued rotation of the shaft. The rotation of the shaft is continued until the point of the drill is imbedded slightly in the remotecortex of the bone as shown in Figures 1 and 2. This final position of the screw becomes apparent to the surgeon through increased resistance presented to the screw when the drill contacts the opposite cortex of the bone.

' The partial imbedding of the drill point in the or the usual ilnders, flanged sleeves. and the like which were deemed necessary in the ordinary attaching means. Moreover, the longitudinal grooves I provide for the outward discharge or cuttings produced by the drilling and thread-cutting operations, and the screw is in.

stalled in sterile condition and in a minimum of time. I v 1 In accordance with the patent statutu I have described what I now believe to be the preferred form of construction, but inasmuch as various changes may be made in the structural details without departing from .the spirit of the invention it is intended that all such changes he included within the scope of the appended claims.

What I claim is:

l. A device of the character described comprising a surgical screw for securing skeletal splints, said surgical screw including a shaft, a drill portion formed on an end of the shaft, said drill portion provided with relatively shallow grooves and terminating in a tapered point, screw threads i'ormed on the shaft above the drill portion and extending a suiiicient distance to permit the threads to engage the adjacent cortex of a bone when the drill point is lmbedded ln-the opposite aeeaaaa 2. A device or the character described comprisportion provided with relatively shallow grooves and terminating in a tapered point, screw threads i'ormedonthesbaitabovethedrlllportionand adapted to engage the adiacent cortex when the drill point is imbedded in the opposite cortex 01' a bone, the threads adjacent the drill portion being interrupted to provide a self-tapping POI- tion,andoneormorelongitudina1groovesin said shaft. said groove or grooves being parallel totheaxisottheshattandterminatingina surtace having a radiu of curvature. the interrupted thread of the self-tapping portion being formed by said longitudinal groove or grooves, said groove or grooves extending to the drill portion on the end 0! the shait.

- HERBERT H. HAYNES.

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