Tissue measuring and suturing device
FIELD OF THE INVENTION 
     The invention generally relates to devices for sizing and measuring body tissue, and more specifically relates to devices for sizing the diameter and measuring the length of such tissue as well as for suturing the ends of such tissue at fixed predetermined locations. 
     BACKGROUND OF THE INVENTION 
     In certain orthopaedic reconstruction procedures such as a semitendinosus gracilis composite graft or a mid-third patellar tendon graft, it is necessary to remove a piece of tendon from a patient&#39;s knee area. After the tendon has been removed, it is used to replace either the anterior or posterior cruciate ligament. These tendons and ligaments are illustrated in FIG. 1. The semitendinosus gracilis composite graft is illustrated as element 12, and the mid-third patellar tendon graft is illustrated as element 14. The anterior and posterior ligaments are illustrated as elements 16 and 18. 
     The anterior and posterior ligaments 16, 18 are generally cylindrical ligaments. Therefore, when tendon grafts are taken to reconstruct these cruciate ligaments, it is desirable for the grafts to be uniformly cylindrical. It is also important to be able to determine the precise diameter of the tendon graft as well as the length of the graft. It is necessary to know these dimensions in order to drill a tunnel 20 (FIG. 2) through a patient&#39;s tibia and fibula which approximates the diameter of the tendon graft. 
     It is important that the diameter of the tunnel 20 is well matched with the diameter of the tendon graft so that the tendon is securely imbedded when inserted in the tunnel. If the tunnel is too large, irritation of the tendon may occur. This irritation may particularly occur in the area where the tibia and fibula meet and rub against each other as a patient flexes his knee. It is also important to know the precise length of the tendon in order to determine the appropriate length of the tunnel to be created. It is necessary that this tunnel be positioned to produce the optimal isometric configuration to accommodate the harvested graft. 
     In the past, relatively awkward devices were used to measure the diameter of a tendon graft. These devices consisted of a series of cylindrical tubes that ranged in diameter from six to fourteen millimeters in one millimeter increments. Each of these tubes were approximately two inches in length. After a tendon graft had been harvested, the graft was forced into a tube to determine if the graft had the same diameter of the tube. 
     Many grafts did not have uniform diameters throughout the length of the graft. Therefore, it was possible to obtain a misreading of the diameter of the graft since a portion of the graft may appear to fit snugly within the tube and comply with the sizing tube. The tubes were awkward to work with because the tendon grafts are pliable and can be difficult to insert in a tube without deforming the graft. Therefore, a need existed to develop a single device which was relatively easy to handle and could easily measure the diameter of a tendon. 
     As discussed above, it is also important to be able to determine the precise length of a tendon graft. In the past, a separate device, such as a simple ruler, was used to measure the length of the graft. This required that medical personnel have both a series of measuring tubes and a separate measuring tape or ruler available in the operating room to size the diameter and measure the length of a graft. 
     After the size of the diameter and length of a graft has been determined, a plurality of sutures are generally inserted in each end of the graft. The sutures are used to pull the graft through the tunnel and position anchor screws 22 at each end of the graft after the graft has been located in the tunnel. Generally, three sutures are placed in each end of the graft to accomplish these tasks. It is desirable that these sutures be evenly distributed at each end of the graft. This is particularly important in a bone-to-bone, mid-third patellar procedure. In the past, it has been difficult to hold the end of a bone plug while the sutures were inserted in the graft without either accidentally dropping the graft or pricking the finger of the medical personnel holding the graft. Therefore, a need existed to develop a device which held the end of a graft in a fixed position while a series of sutures were being placed in the graft without deforming or dropping the graft. 
     The subject invention is a single device which meets all of the needs described above. In addition, the subject invention allows medical personnel to fixate, measure, size, and suture a tendon graft or bone plug without contaminating the graft or plug or exposing it to other damage. 
     Thus, it was a primary object of the subject invention to provide a device for easily determining the diameter of a tendon graft or bone plug. 
     It was also an object of the invention to provide a device for measuring the length of a tendon graft or bone plug. 
     It was still another object of the invention to provide a device which may maintain the end of a tendon graft or bone plug in a fixed position while a plurality of sutures are inserted therethrough. 
     It was yet another object of the invention to provide a single device which accomplishes each of the tasks described above and which is easy to manipulate by medical personnel. 
     Other objects and many of the attendant advantages of the subject invention will become apparent from the detailed description that follows with the accompanying drawings. 
     SUMMARY OF THE INVENTION 
     A device for measuring the diameter of an object is provided. The device includes first and second arms. Each arm has a series of semicircular sizing sleeves in which each sleeve is positioned to mate with another identically sized sleeve on the other arm. The semicircular sizing sleeves mate to form circular sleeves when the arms are brought together in a closed position, in which the arms are in parallel juxtaposition with one another. In the preferred embodiment, a series of semicircular sizing sleeves are provided on each arm and the sleeves have diameters which range from six to fourteen millimeters in one millimeter increments. 
     In the preferred embodiment, the arms are hinged together at the proximal end of each arm with a hinge means. A gripping means is provided at the distal end of each arm to allow medical personnel to open and close the arms without touching the portion of the arms that contain the semicircular sizing sleeves. 
     A locking mechanism is also provided in the preferred embodiment at the distal end of each arm that interlocks when the arms are in the closed position. The locking mechanism allows the device to be maintained in the closed position without the use of additional force. 
     Measurement indicia indicating the diameter of each sizing sleeve is located on the device. This indicia allows medical personnel to easily determine the diameter of a tendon graft or bone plug. Also provided in the preferred embodiment is an unique length measurement indicia. The length measurement indicia extends from the distal end of one arm to at least a portion of the proximal end of the other arm and allows medical personnel to measure the length of a graft that is longer than the length of a single arm. In the preferred embodiment, the arms open outward in a &#34;butterfly&#34; fashion to form a straight line along the outer surface of each arm; the unique length measurement indicia is located along the outer surface of each arm. 
     Also included in the preferred embodiment of the subject invention is at least one cavity which extends through each of the arms at one or more of the semicircular sizing sleeves. This cavity has an axis which is perpendicular to the axis of the sizing sleeve to allow a puncturing device or suture to be inserted through the cavity and through a tendon graft or bone plug located in a sizing sleeve. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There follows a detailed description together with accompanying drawings of a preferred embodiment of the invention. However, it is to be understood that the invention is capable of numerous modifications and variations apparent to those skilled in the art that are within the spirit and scope of the invention. 
     FIG. 1 is a perspective view of a patient&#39;s knee area illustrating the anterior and posterior ligaments as well as the mid-third patellar mid-section and the semitendinosus gracilis; 
     FIG. 2 is a perspective view of a patient&#39;s knee area illustrating a reconstructed tunnel configuration; 
     FIG. 3 is a perspective view of the preferred tendon sizing and measuring device; 
     FIG. 4 is a perspective view of the arm portions of the preferred embodiment of the invention when the arms are in a closed position; 
     FIG. 5 is another perspective view of the arm portions of the device illustrating diameter measuring indicia; 
     FIG. 6 is a perspective view of the subject device in which the arms are in a fully opened, butterfly position; 
     FIG. 7 illustrates another embodiment of the invention in which a ratchet means is used to maintain the arms of a device in a closed position; and 
     FIG. 8 illustrates a chamfered edge of a suture cavity. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Refer now to FIG. 3 which is a perspective view of the preferred embodiment of the subject device 24. As can be seen in the figure, the device 24 includes first and second arms 26, 28. Each arm has an inner surface 30, an outer surface 32, a proximal end 34, and a distal end 36. The inner surface 30 of each arm 26, 28 is provided with a series of semicircular sizing sleeves 38. Each sleeve is positioned to mate with another identically sized sleeve on the inner surface 30 of the other arm to produce a circular sizing sleeve when the first and second arms 26, 28 are placed in closed parallel juxtaposition with one another. 
     The circular sizing sleeves are illustrated in FIG. 4 which is a perspective view of a portion of the preferred embodiment of the subject invention. As can be seen in FIG. 4, a series of semicircular sizing sleeves are provided in which the diameter of each sleeve is incrementally larger than the diameter of an adjacent sleeve. In the preferred embodiment of the invention, the sleeves range in diameter from six to fourteen millimeters in increments of one millimeter. 
     In the preferred embodiment of the invention, the semicircular sizing sleeve having the smallest diameter is located at the proximal end 34 of each arm, and the sleeve having the largest diameter is located at the distal end 36 of each arm. This allows medical personnel to manipulate the arms without having to open the arms to an excessive amount to insert a relatively large tendon graft or bone plug in the largest sizing sleeves. 
     A hinge means 40 is provided at the proximal end 34 of each arm to join the proximal ends together. The arms can be opened and closed in a &#34;scissor-like&#34; fashion to allow medical personnel to insert a section of tendon graft or bone plug in any of the semicircular sleeves. The arms then can be closed together to determine if the tissue is the same size as the sleeve 38 by gently pulling the tissue through the sleeve 38. If the tissue is the same approximate size as the sleeve 38, a slight resistance will occur as the tissue is pulled through the sleeve. This allows medical personnel to easily determine the proper size of a drill to be used in creating a tunnel through a patient&#39;s fibula and tibia. 
     One of the features of the subject invention is the ability to shape a bone plug using the semicircular sleeves 38 to compress the plug into a more uniform diameter. The device can be also used to remove or scrape small portions of meaty substance from a tendon graft or bone plug by pulling the graft or plug through an appropriately sized sleeve. 
     In the preferred embodiment of the invention, a gripping means 42 is also provided at the distal end 36 of each of the arms. The gripping means allows medical personnel to open and close the arms without touching the portion of the arms that contain the semicircular sizing sleeves 38. In the preferred embodiment, the gripping means includes a loop handle 44 at the distal end 36 of each of the arms. Medical personnel can insert a finger or thumb through each loop handle 44 to open and close the arms with a single hand. This allows a medical personnel to easily grip the tendon graft or bone plug in one hand while manipulating the subject device with the other hand to determine the size of the diameter of a graft or plug. 
     In one embodiment of the invention, a locking means 46 is provided to stabilize the arms in a closed position. The locking means 46 allows medical personnel to close the arms of the device and maintain the arms in a closed position without the use of additional force. In the preferred embodiment of the invention, the locking means 46 includes a spring-loaded pin 48 at the distal end 36 of one of the arms 28 and a mating orifice 50 at the distal end of the other of the arms 26. The pin 48 and the orifice 50 interlock with each other when the arms are in a closed position. 
     In another embodiment of the invention, a ratchet means such as those commonly used with hemostats may be provided to lock the device in a closed position. Such a ratchet means is illustrated in FIG. 7. 
     Refer now to FIG. 5 which is another perspective view of the preferred embodiment of the subject invention. As can be seen in the figure, diameter measurement indicia 52 is provided to indicate the diameter of each semicircular sizing sleeve. In the preferred embodiment of the invention, the measurement indicia 52 includes a numerical indication 54 of the diameter of each sleeve on one of the arms and an indication of the unit of numerical measurement 56 on the other of the arms. 
     Also, in the preferred embodiment, the measurement indicia is laser engraved on each of the arms. The advantage of laser engraving the indicia is that it creates a smooth engraved etching which can be readily sterilized by a variety of means. The laser engraving is also beneficial in that it provides a smooth surface texture which can be easily read by medical personnel and is not subject to fading or general wear. 
     The subject invention also includes a unique method of measuring the length of a tendon graft or bone plug. This can be seen in FIG. 6, which is a perspective view of the subject invention in which the arms are in a completely open or &#34;butterfly&#34; position. As can be seen in the figure, the arms of the subject device can be moved from a closed position in which the inner surfaces 30 are closed upon one another to an open, butterfly position in which the outer surfaces 32 extend to form a straight line. The outer surfaces 32 are provided with linear measurement indicia 58 that extend continuously from a distal end 36 of one arm to at least a portion of a proximal end 34 of the other arm. Thus, the linear measurement indicia 58 can be substantially longer than the length of a single arm. By opening the arms to a completely open butterfly position, it is possible to provide a measuring device which can measure tendon grafts or bone plugs that are up to twice as long as the length of a single arm. 
     The subject invention is unique in that it uses the outer surfaces of each arm to provide a means of measuring the length of a bone plug or tendon graft while it uses the inner surface of each arm to measure the diameter of the same plug or graft. Thus, a single device can be used to perform functions that were previously performed by multiple devices. This greatly simplifies the sizing and measuring of a bone plug or tendon graft during a medical procedure. This device also improves the accuracy of measurement and enhances the ability of medical personnel to handle a graft or plug without damaging or dropping the tissue. 
     As can be seen in FIG. 7, one of the features of the subject invention is that the sizing sleeves can be used to hold body tissue in a fixed position. This is accomplished by inserting the tissue in a sizing sleeve which is slightly smaller than the diameter of the tissue to be held. When the arms are in a closed position, the tissue is snugly held in the sizing sleeve through compressive forces. 
     This ability to hold tissue snugly in a sizing sleeve is very important. It allows medical personnel to insert sutures into one end of the tissue without exposing the medical personnel&#39;s hands to the possibility of needle sticks. This is important in view of the desire to prevent transmitting AIDS or other communicable diseases through accidental needle sticks. The ability to snugly hold tissue while inserting sutures is also important in preventing accidental droppage of the tissue which would prevent it from being used for reconstructive purposes and would considerably complicate the outcome of the procedure. 
     In the preferred embodiment of the invention, means are provided for enhancing the ability of medical personnel to insert sutures in the ends of relatively impermeable body tissue, such as tendon grafts and bone plugs. Specifically, at least one cavity 60 is provided which extends through each of the arms at a semicircular sizing sleeve. The cavity has an axis which is perpendicular to the axis of the sizing sleeve. Medical personnel can insert a puncturing device through the cavity and through any tissue located in the sizing sleeve. This cavity provides a means for accurately locating the position of a suture in the end of a tendon graft or bone plug. 
     In the preferred embodiment of the invention, a series of three cavities 62 extend through each of the arms in vertical alignment at each semicircular sizing sleeve. The cavities are spaced apart from each other at a predetermined distance to provide a highly accurate method of locating a series of sutures at each end of a bone plug or tendon graft. In the preferred embodiment, the cavities are located 3/16ths of an inch apart from one another. 
     As discussed above in the Background of the Invention, the sutures are used to pull a tendon graft or bone plug through a tunnel and position each end of the graft or plug. The sutures are used to pull on the opposite ends of the graft or plug once it has been inserted in the tunnel to create a desired amount of tension on the graft or plug prior to permanent anchoring of the graft or plug. The sutures can then be wrapped around anchoring screws to provide additional security in maintaining the implanted tissue in the proper location. 
     In the preferred embodiment of the invention, the cavity is chamfered at the interface between the inner surface of each arm and the cavity 64 to provide a guide for centering a puncturing device. This forces a puncturing device toward the center of each cavity when it is inserted through the cavity. This is illustrated in FIG. 8. 
     A variety of materials can be used to manufacture the subject device. In general, it is desired that the material be of a high corrosion resistant composition. In the preferred embodiment of the invention, a 316 U.S. standard steel grade was chosen. 
     While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.