The present invention relates to orthopaedic devices, and, more specifically, to templates and methods of making same for orthopaedic implants.
The field of orthopaedics has been towards sterile options regarding the equipment used during surgical procedures. This trend has as its objective, lower risk of infection, insured product integrity and potential improvement efficiency of care.
One aspect experiencing increased attention is in the area of a template or trial that is used for sizing orthopaedic implant devices used to repair a trauma or other problem with bone material. The templates are used to select the proper size implant during a surgical procedure to avoid contamination of a very expensive implant device, if it proves to be not the right size for a particular application. Currently, such templates are manufactured from machined, stainless steel or a 1000 grade aluminum templates that are anodized. Both template types are relatively expensive but less costly than the implant. With the trend toward a total sterile environment for orthopaedics, the existing templates require re-sterilization and indefinite use, thereby increasing the total cost of the medical procedure.
What is needed in the art therefore is an orthopaedic implant template that is manufactured with sufficiently reduced cost to economically justify a one use option for the template.
The present invention provides a low cost template with sufficient economy of manufacturing to enable a single use.
In one form, the invention is an orthopaedic template formed from a metal sheet by photo chemical machining to cut through the metal sheet for the template outline, hole positions and length marks. The thin metal sheet is also photo etched to provide product information.
In another form, the invention is a method of making an orthopaedic implant template from a metal sheet by applying a photo sensitive sheet to at least one face of the metal sheet. A photo negative pattern is supplied to the photo sensitive sheet with the pattern being configured to the outline of the template and to any openings. The sheet is exposed to a light source to harden the exposed pattern and the non-hardened portions are chemically removed to form the final pattern. The resultant sheet metal is etched to form the outline of the templates and the openings.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates one embodiment of the invention and such exemplifications is not to be construed as limiting the scope of the invention in any manner.
Referring specifically to
The template 10 has a longitudinal axis A and an additional reference axis B extending tangentially with respect to axis A within the proximal section 16. A plurality of holes 24 and 26 are provided in the proximal section 18. As observed in
The template 10 is also provided with informational indicia on both faces 12 and 14 of the template 10. These indicia include whether it is for a right or left bone as indicated at 40 or right 42. It should be noted that the
In accordance with another aspect of the present invention, the template 10 is formed by photo chemical machining and photochemical etching. This process enables significant reductions in manufacturing costs and reduces the unit cost of template 10 to the point where it is economically feasible to provide the template 10 in a one use package. The process begins with providing a sheet of bio-compatible metallic material, typically stainless steel used in surgery. A photo sensitive sheet with an adhesive back is rolled preferably on both sides of the sheet and then a machine loads a photo negative of the material of the ultimate configuration in a glass press and this is done on both sides. Subsequently, both sides are exposed to a light source such as ultraviolet to harden the exposed portion of the template configuration, namely what is contained outside of the negative. The material that has not been hardened is then stripped by a bath which immerses the sides in a chemical that strips the exposed areas away, leaving the configuration of the part as shown in
On the portion of the template on which the indicia regarding information is placed, the etching is only on one side, since the etching goes through more than half of the thickness of the template 10. Accordingly, the photo negative used to manufacture the template 10 is set up so that the indicia are positioned on opposite sides of the longitudinal axis A and the transverse axis B to prevent any breakthrough, while providing sufficient depth to the indicia. This enables sufficient optical contrast to easily read the various indicia placed on the template 10.
The templates 10 may be placed in an array 52 shown in
The thickness of the templates 10 can be up to 1.5 mm and preferably is 0.3 mm. They are formed from stainless steel suitable for surgical applications. The thickness is thick enough for the lettering on the indicia to show but thin enough to flex so that they may be bent to conform to the bone structure. Preferably, they are made from spring tempered material so that they may be reused if necessary.
The templates will in
The use of photo chemical machining and etching to manufacture the templates 10 provides a cost of manufacturing that is sufficiently reduced to make the templates 10 available in a one use application. For this application, a template 10, or an array of templates would be prepackaged and sterilized by subjecting them to gamma rays, for example.
In contrast to previous methods of machining and forming expensive materials, the photo chemical machining and etching enables a significant flexibility without the excess manufacturing cost associated with prior methods. In addition, the templates 10, because they are etched on both sides, allow a right and left presentation in a single element. Because the templates 10 are made of spring steel, they may flex to accommodate an orthogonal projection of the implant they represent. In this case, the shape of the template is not the actual configuration of the implant but a projection of the shape onto a plane that is not parallel to the plane of the implant. This feature enables a surgeon to see in an X-ray or other image if the actual template is the appropriate size when muscle tissue and other body components proven presentation of the template in the X-ray in a plane parallel to the plane of the implant in the human anatomy. In addition, the template 10 may have indications of the trajectory of the screws fastening the implant to a bone. As one example of this purpose, a pair of tabs 66 and 68 (show by dashed lines in
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
Number | Date | Country | |
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Parent | 14169744 | Jan 2014 | US |
Child | 15818070 | US |