Title:
Orthopedic pin identification means
United States Patent 3915162
Abstract:
Surgical pins for connecting osseous tissue wherein the pins are readily separable and identifiable under Xray conditions by reason of the inclusion on the shank of the pin in addition to all of the operating elements of the pin of additional three dimensional markings such as screw threads with different such markings for each of the pins which may be used at a particular location so that the pins may be readily identified and segregated.
Application Number:
05/442107
Publication Date:
10/28/1975
Other Classes:
606/102, 606/912
International Classes:
A61B17/86; A61B19/00; A61B17/68; A61B19/00; (IPC1-7): A61F5/04
Field of Search:
128/92BA,92BB,92R,92B,83 85
Primary Examiner:
Gaudet, Richard A.
Assistant Examiner:
Yasko J.
Attorney, Agent or Firm:
Ostrolenk, Faber, Gerb & Soffen
Claims:
The embodiments of the invention in which an
exclusive privilege of property is claimed are defined as follows
1. A method of detecting any incorrectly placed orthopedic pin in a set of orthopedic pins inserted in osseous tissue, which comprises providing a set of orthopedic pins wherein each said pin has a threaded end, a shank, and a head for receiving a turning tool and wherein the shanks of said pins are provided with a pin identification member spaced from the threaded end of the respective pin, said members being visibly different so as to be individually identifiable in an X-ray radiograph; inserting said pins in osseous tissue; providing an X-ray radiograph of said tissue with the pins inserted; and examining said radiograph to compare pin locations by means of said differing members to detect an incorrectly located pin.
2. A method as set forth in claim 1, wherein said identification members are integral with the material of said pin shanks and encompass the respective shanks.
3. A method as set forth in claim 1, wherein said identification members are comprised of an increasing number of screw threads from pin to pin and said threads being capable of screwing into osseous tissue and matching the pitch of the threaded ends of respective pins.
4. A method as set forth in claim 1, including in said set a pin having a shank without an identification member so as to be thus distinguishable by X-ray radiograph from the other pins of said set.
Description:
The present invention relates to orthopedic pins used for the purpose of securing and immobilizing fractured bone elements with respect to each other, interconnecting separate ossification centers or otherwise interengaging bone tissue either temporarily or permanently while the bone sets, mends or heals in the integrated position created by the utilization of the pins.
One of the major problems which arises in connection with the utilization of such pins is one of identification. Where two or more pins are used in the operation of interconnecting bone elements then, in order to identify the particular pin by means of an Xray it may be necessary in the simplest circumstances to take two or more Xray exposures but in the more usual circumstances it may be necessary to advance one or more of the pins in order to identify it by its change in location. This unnecessarily increases the time that a patient must spend in the operating room and under anesthetic and increases the difficulty of the surgeon and orthopedist who perform this operation. It thus becomes extremely desirable to reduce the amount of time involved in any such procedure.
The present invention contemplates that the pins themselves carry identification which may be distinguishable by Xray and/or radiograph and for this purpose the invention contemplates the utilization of an extra thread, two threads or three threads or as many more additional threads as are needed on the body of the pin so that each pin may be distinguished from the other.
While the number of threads actually used will be obvious to the surgeon who is operating at the time it also becomes desirable to place an identification number corresponding to the number of threads on another and highly visible portion of the pin. While this identification will not be visible under Xray the additional threads will be visible and thus will serve as a simplified identification means so that the location of each pin may readily be determined by Xray and the pins may readily be distinguished from each other under Xray conditions without the need for taking a plurality of Xray exposures at different angular positions in order to attempt to locate the pins and to determine which pin may require some particular action and without the necessity for further operation or for extension of the time of surgical operation to the detriment of the patient as well as the personnel participating in the operation.
Thus the primary object of the present invention is the provision of simplified means for identification of orthopedic pins by the utilization of Xrays without the need for a plurality of Xray radiographs and without the need for movement of the pins themselves changing their relative location in order to be able to identify a particular pin.
A further object of the present invention is the utilization of such identification means which may be visible in an Xray radiograph such as, as herein more specifically disclosed, the utilization of extra threads or extra extensions or three-dimensional markings on the pin itself so that it may readily be identified.
The foregoing and many other objects of the present invention will become apparent in the following description and drawings in which:
FIG. 1 is a side view of one of the pins of the present invention.
FIG. 2 is a side view of another pin of a set of which FIG. 1 is a part having an identification marking thereon in the form of a single 360° turn of a screw thread.
FIG. 3 is a view corresponding to that of FIGS. 1 and 2 showing a third pin of the set having an identification marking thereon in the form of two screw threads.
FIG. 4 is a view corresponding to FIGS. 1, 2 and 3 but completing the set, which includes the said other members, and having an identification marking thereon in the form of three screw threads.
FIG. 5 is a view of a pin of the type previously used corresponding essentially to that of FIG. 1 having an extension which facilitates handling thereof and which extension may be snapped off by an appropriate implement.
Referring now to the Figures it will be seen that each of the pins 10, 11, 12, 13, 14 of FIGS. 1-5 is provided with a principal shank 20, a screw thread 21 and a relatively pointed end 22 which will permit the pin to make its entry under appropriate force exerted by the surgeon.
Each of the pins is provided at the end of the shank opposite the screw thread 21 with a hex nut formation 25 integral or integrated with the shank 20 so that an appropriate tool may be utilized thereon in order to drive the point 22 and the screw thread 21 of each pin through the bone tissue into the proper position. Each of the pins may, if desired, have additional extensions 30 as shown in FIG. 5 which may facilitate handling of the pins and may facilitate positioning of them while an operation is taking place and which may be clipped off at the hex nut 25 at the appropriate time.
The identification means provided for the pin is the utilization of the single screw thread 35 shown on the pin 11 of FIG. 2, the double screw thread 36 on pin 12 of FIG. 3 and the triple screw thread 37 on pin 13 of FIG. 4. These screw threads are remote from the operative portion of the pin which first enters and is driven into the bone, to wit the pointed end 22 of screw thread 21; but each of the additional screw threads 35, 36, 37 of FIGS. 2, 3 and 4, because they are three dimensional and therefore highly visible and will cast an appropriate shadow in an Xray radiograph, will serve readily to identify each of the pins.
Where actual screw threads are used as shown in FIGS. 2, 3 and 4 the pitch thereof will be the same as the operative screw threads 21 so that there will be no problem with respect to operation if any of the pins is driven deep into the osseous tissue.
In those cases where it is not expected that the pins will be driven deep into the osseous tissue it is possible instead of using screw threads 35, 36, 37 to use concentric rings. It is preferred however that the screw threads 35, 36, 37 be used for such identification purposes. Where it is possible that identification may be impeded by the fact that one screw thread, two screw threads and three screw threads are used for separate pins, then various different arrangements of screw threads may be used such as one or two additional screw threads on the shank of the pin for the second pin to be identified; four such screw threads on the shank of the third pin and six such screw threads on the shank of the fourth pin and so on. This will obviate any possible ambiguity that might arise from the fact that a single screw thread may in one particular aspect convey the impression on one side of the shank as being composed of two turns rather than one. This variation is however merely to enhance the facility and exactness of identification.
By this means therefore any extension of time of an operation which may be needed to identify the separate pins is obviated and any further operation which may be required to move one or more pins in order to identify a particular pin is also obviated; it will also become unnecessary to take a plurality of Xray radiographs from different aspects in order to determine the exact location and function of each pin.
In the foregoing the present invention has been described solely in connection with illustrative preferred embodiments thereof. Since many variations and modifications of the present invention will become apparent to those skilled in the art it is preferred that the scope of this disclosure be determined not by the specific illustrative embodiments herein contained but only by the appended claims.