Abstract:
A method of marking a surgical article is described that includes the steps of providing a surgical article having a surface; engraving a portion of the surface to create an engraved surface; darkening an area of the surface that includes the engraved surface; and removing the marking on that area of the surface that does not include the engraved surface.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a surgical article and a method for making a surgical article having one or more identification marks that function to identify information about the article, such as color, size, catalog number and the like, or are used as intra-operative indicia such as angle markings, scale markings or graduated scales. 
       DESCRIPTION OF THE RELATED ART 
       [0002]    Surgical articles, such as devices and instruments, often bear a number of identification markings that serve various purposes. Often the articles bear identification markings that identify, for example, the article product code, serial numbers or batch/lot codes, size, weight or volume of the article, the name of the article, or the name of the manufacturer, etc. The article may also include markings that facilitate the use of the article during a surgical procedure such as angle markings, scale markings or graduated scales. 
         [0003]    Because surgical articles are washed and sterilized after use, it is desirable to mark markings directly on the surface of the surgical articles. Moreover, the shapes of surgical articles are not uniform and portions in which markings are created are not always flat. Accordingly, the markings must be created by a method that does not require the article to be flat, yet in a manner that permits the markings to be read regardless of the shape of the surface. 
         [0004]    In the past, those skilled in the art have engraved or etched markings on surgical articles. However, these methods are not optimal as both engraved markings and laser markings are not always easy to read, especially under poor lighting conditions. In addition, laser markings can wear off due to abrasion, can cause article discoloration, and is difficult to control from a batch-process perspective. 
         [0005]    Those skilled in the art have also attempted to fill engraved markings with a colored epoxy to make it more readable. The method of filling the engravings with epoxy is not easily controlled, however, and the epoxy-stainless-steel bond often fails. 
         [0006]    It is therefore desirable to provide markings for a surgical article that are easy to read, yet durable enough to survive multiple sterilization processes, and relatively inexpensive to manufacture. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a surgical article that has a surface. The surface of the article has markings that have been formed by engraving. As a result, the engraved surfaces do not lie on the same plane as the remaining surfaces of the article. The engraved surfaces are darkened by oxidizing the engraved surfaces by either a chemically marking, laser marking, or another oxidation process. 
         [0008]    A method of manufacturing a surgical article is also provided. The method includes the steps of providing a surgical article having a surface; engraving a portion of the surface to create an engraved surface; darkening an area of the surface that includes the engraved surface; and removing the darkening on that area of the surface that does not include the engraved surface. 
         [0009]    These and other objects, features and advantages of the present invention will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0010]      FIGS. 1A-1C  are perspective views of the sequence of steps of the process of enhancing marking on a representative surgical articles; and 
           [0011]      FIG. 2  is a plan view of a representative surgical article having enhanced marking contrast. 
       
    
    
     DETAILED DESCRIPTION  
       [0012]    Referring now to  FIGS. 1A through 1C  the process of creating a marking on a surgical article, generally referred to as reference numeral  10 , is depicted. Surgical article  10  can be an implant that is left in the body at the completion of surgery or it can be a surgical instrument or device for use in facilitating the surgical procedure. By way of non-limiting example, an implant can be a component of a shoulder, knee or hip implant, a spinal cage, a plate, or any other device that one can leave within a body. Also by way of non-limiting example, surgical instruments or devices can include cutting blocks, rasps, reamers, drills, scissors, cutters, graspers, staple applicators, clip applicators, laser devices, viewing (optical) devices, illuminating devices, and any combination of these. Typically, surgical article  10  is formed of a metal. In some embodiments, surgical article  10  can be formed of stainless steel. 
         [0013]    As is shown in  FIG. 1A , Article  10  has a surface  20  upon which a marking is to be formed. Surface  10  is shown as a flat surface but it may be curved or any combination of different types of surfaces. The first step in the method of marking surgical article  10  is to use an engraver  30  to engrave an engraved surface  31  in surface  20 . Engraved surface  31  does not lie in the same plane as the surfaces adjacent to engraved surface  31 . As a result, engraved surface has a three dimensional component defined by the amount of material removed during the engraving step. Engraved surface  31  has a depth relative to surface  20 , and thus has side walls and a bottom surface. In the depicted embodiment, engraved surface  31  is shown as a straight line. Optionally, article  10  is grit blasted to remove any sharp edges and to clean surface  20  and engraved surface  31 . 
         [0014]    In the next step, depicted in  FIG. 1B , engraved surface  31  and an area preferably surrounding engraved surface  31 , hereinafter referred to as area  33 , are treated to darkening area  33  and engraved surface  31  by a darkening device shown as reference numeral  40 . Area  33  can be darkened in a number of ways without without filling engraved surface  31  with a colored or black liquid. Among the known methods, one can laser mark area  33 , black oxidize area  33  or chemically etch area  33 . In each case, area  33  of surface  20  is treated with a process known in the art to darken area  33 . While darkening device  40  is depicted as a pad that might be used to deliver a chemical or an oxidizing agent, it is understood that it may be any device used by one skilled in the art to darken a surface, including a laser. 
         [0015]    Finally, as is shown in  FIG. 1C , that part of area  33  that is not engraved surface  31  is treated to remove the darkening, thereby leaving engraved surface  31  as the darkened portion of surface  20 . The darkening may be removed by a limishing or polishing or grinding step, for example, to remove the darkening. In either case, as little as the top few microns of surface  20  are removed, but in any event a thickness that removes that portion of surface  20  that was darkened during the darkening step or at least lightens the darkened portion of surface  20  relative to the darkened engraved surface  35 . 
         [0016]    Optionally, surface  20 , including engraved surface  31  may be passivated at any point during the process or at multiple points during the process. 
         [0017]    In this manner engraved surface  31  is darkened relative to the surrounding surface area to leave a darkened engraved surface shown as  35  in  FIG. 1C . As a result, the contrast of the darkened marking with the surrounding surface area is increased, thereby making the marking more readable at all angles and under different lighting conditions. Furthermore, the combination of steps produces a darkened marking that will survive even if article  10  is subjected to multiple sterilization processes. 
         [0018]    An example of the resulting article  10  with a darkened engraved surface  35  is shown in  FIG. 2 . That figure shows that surface  20  is engraved in text that reads “L 753” and R 357”. The contrast between the text of article  10  and the area surrounding the text is enhanced by the darkening as compared with text that had no darkening. 
         [0019]    Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments and that various other changes and modifications may be effected herein by one skilled in the art without departing from the scope or spirit of the invention.