Tissue press and system

Abstract

A tissue press for shaping or compressing a piece of tissue comprises first and second members movable relative to each other. A first forming element of a predetermined shape is selectively engageable on the first member. A second forming element of predetermined shape is selectively engageable on the second member. The first and second forming elements are positionable on opposite sides of the piece of tissue. The first and second members are relatively movable between a first spaced apart condition and a second condition in which the piece of tissue is held between the first and second forming elements. Means are preferably provided for monitoring and controlling the amount of pressure applied to the piece of tissue, in order to maintain the tissue in a viable living condition. Means may also be provided for draining off fluid from compressed. tissue, so that the tissue can be implanted in a compressed state and imbibe fluid from the host site. A retainer, which may be expandable, can be used to maintain the tissue graft in a compressed condition.

I claim:  
     
         1 . A tissue press for shaping a piece of tissue to a particular overall shape for implantation, comprising: 
 first and second relatively movable members connected with each other;    said first member having a surface portion receiving a selected one of a plurality of first forming elements of predetermined shapes, said first forming element having a first forming surface for providing a first portion of the overall shape of the reshaped tissue,    said second member having a surface portion receiving a selected one of a plurality of second forming elements of predetermined shapes, said second forming element having a second forming surface for providing a second portion of the overall shape of the reshaped tissue,    said first and second forming elements being positionable on opposite sides of the piece of tissue to be shaped, and    actuator means connecting said first and second relatively movable members and operable to move said second forming element toward said first forming element to engage and shape the piece of tissue between the first and second forming elements.    
     
     
         2 . A tissue press as defined in  claim 1  wherein each one of said plurality of first forming elements is removably received on said surface portion of said first member.  
     
     
         3 . A tissue press as defined in  claim 2  wherein each one of said plurality of second forming elements is removably received on said surface portion of said second member.  
     
     
         4 . A tissue press as defined in  claim 1  comprising means for draining off fluid from between said first and second forming elements.  
     
     
         5 . A tissue press as defined in  claim 1  comprising means for monitoring the amount of pressure applied to the piece of tissue in order to minimize tissue necrosis.  
     
     
         6 . A tissue press as defined in  claim 1  comprising means for limiting the amount of pressure applied to the piece of tissue in order to minimize tissue necrosis.  
     
     
         7 . A tissue press as defined in  claim 1  wherein said first and second forming elements when brought together define between them an open forming chamber.  
     
     
         8 . A tissue press as defined in  claim 1  wherein said first and second forming elements when brought together define between them a closed forming chamber.  
     
     
         9 . A tissue press for shaping a piece of tissue to a particular overall shape for implantation, comprising: 
 a first forming element having a first forming surface for providing a first portion of the overall shape of the reshaped tissue;    a base member supporting said first forming element and including surface means for supporting said base member and thereby said apparatus on an external support surface;    a second forming element having a second forming surface for providing a second portion of the overall shape of the reshaped tissue, said first and second forming elements being positionable on opposite sides of the piece of tissue to be shaped;    a manually engageable member connected with said base member and supporting said second forming element, said manually engageable member being movable relative to said base member to move said second forming element toward said first forming element to reshape the piece of tissue between the first and second forming elements; and    means for blocking application to the piece of tissue of pressure in excess of a predetermined amount.    
     
     
         10 . A tissue press as defined in  claim 9  comprising means for draining off fluid which may be expressed from the piece of tissue.  
     
     
         11 . A tissue press for compressing a piece of tissue, comprising: 
 a base member;    a first compressing part on said base member for receiving the piece of tissue thereon;    a movable member connected with said base member and movable relative to said base member;    a second compressing part on said movable member, said first and second compressing parts being positionable on opposite sides of the piece of tissue when the piece of tissue is received on said first compressing part; and    said movable member being movable toward said base member to move said second compressing part toward said first compressing part to compress the piece of tissue between the first and second compressing parts.    
     
     
         12 . A tissue press as defined in  claim 11  wherein said base member includes surface means for supporting said base member and thereby said apparatus on an external support surface, said movable member being pivotally supported by said base member.  
     
     
         13 . A tissue press as defined in  claim 11  wherein said first and second compressing parts each include a cylindrical surface portion and cooperate to compress tissue into a cylindrical shape.  
     
     
         14 . A tissue press as defined in  claim 11  comprising means for monitoring the amount of pressure applied to the piece of tissue.  
     
     
         15 . A tissue press as defined in  claim 14  wherein said means for monitoring pressure comprises a pressure sensor in one of said first and second compressing parts for sensing the amount of pressure on the piece of tissue.  
     
     
         16 . A tissue press as defined in  claim 14  wherein said means for monitoring pressure comprises display means for displaying the amount of pressure applied by said first and second compressing parts.  
     
     
         17 . A tissue press as defined in  claim 11  comprising means for limiting the amount of pressure applied to the piece of tissue in order to minimize tissue necrosis.  
     
     
         18 . A tissue press as defined in  claim 17  wherein said means for limiting comprises a pressure relief mechanism for blocking movement of said second compressing part, toward said first compressing part, upon the application of pressure to said piece of tissue in an amount above a predetermined amount.  
     
     
         19 . A tissue press for compressing a piece of tissue, comprising: 
 first and second relatively movable support members connected with each other;    said first support member having a surface portion receiving a selected one of a plurality of first compression members having predetermined forms, said first compression member adapted to receive the piece of tissue thereon,    said second support member being movably connected with said first support member and having a surface portion receiving a selected one of a plurality of second compression members having various forms,    said first and second compression members being positionable on opposite sides of the piece of tissue to be compressed,    said first and second support members being relatively movable to move said second compression member toward said first compression member to engage and compress the piece of tissue between the first and second compression members;    means for draining off fluid which may be expressed from the piece of tissue to be compressed; and    means for limiting the amount of pressure applied to the piece of tissue in order to minimize tissue necrosis.    
     
     
         20 . A tissue press for shaping a piece of tissue, comprising: 
 first and second members;    a plurality of first forming elements of different predetermined shapes selectively engageable on said first member,    a plurality of second forming elements of different predetermined shapes selectively engageable on said second member,    said first and second forming elements when on said first and second members being positionable on opposite sides of the piece of tissue, and    said first and second members being relatively movable between a first spaced apart condition and a second condition in which said piece of tissue is held between said first and second forming elements.    
     
     
         21 . A method of reshaping tissue for use as graft material comprising the steps of: 
 determining the shape which the tissue should possess as graft material;    providing a tissue press;    selecting forming elements adapted to press tissue approximately to the desired shape;    placing the forming elements on the tissue press;    placing the tissue in the tissue press between the forming elements;    operating the tissue press to shape the tissue between the forming elements to give the tissue the desired shape; and    controlling the pressure on the tissue during said shaping step to minimize damage to or necrosis of the tissue.    
     
     
         22 . A method of preparing tissue for use as graft material comprising the steps of: 
 determining the shape and size which the tissue should possess as graft material;    placing the tissue in a tissue press having forming elements adapted to press tissue approximately to the shape and size desired;    compressing the tissue in the tissue press to give the tissue the shape and size desired;    controlling the pressure on the tissue during the compressing step to minimize damage to or necrosis of the tissue; and    draining off fluid expressed during said compressing step.    
     
     
         23 . A method as set forth in  claim 22  further comprising the step of implanting the compressed tissue as graft material in a body opening in a compressed and defluidized condition whereby the compressed tissue will imbibe bodily fluids and form a mechanical interlock with the surface defining the body opening.  
     
     
         24 . A method as set forth in  claim 23  further comprising the step of placing a retaining member on the compressed tissue to maintain the compressed tissue in a compressed condition prior to implantation of the compressed tissue as graft material.  
     
     
         25 . A tissue press for compressing or shaping a piece of tissue, comprising: 
 a first member, and a first forming element on said first member;    a second member connected with said first member, and a second forming element on said second member;    said second member being movable toward said first member to move said second forming element toward said first forming element to compress or shape the piece of tissue between the first and second forming elements; and    means for selectively controlling the temperature of the piece of tissue while it is being compressed or shaped.    
     
     
         26 . A tissue press as set forth in  claim 25  wherein said means for selectively controlling the temperature of the piece of tissue comprises means for heating the piece of tissue.  
     
     
         27 . A tissue press as set forth in  claim 25  wherein said means for selectively controlling the temperature of the piece of tissue comprises means for cooling the piece of tissue.  
     
     
         28 . A tissue press for compressing or shaping a piece. of tissue, comprising: 
 a first member, and a first forming element on said first member;    a second member connected with said first member, and a second forming element on said second member;    said second member being movable toward said first member to move said second forming element toward said first forming element to compress or shape the piece of tissue between the first and second forming elements; and    means for selectively removing excess tissue from the piece of tissue after it is compressed or shaped.    
     
     
         29 . A pneumatic press for compressing or shaping a piece of tissue, comprising: 
 a first member, and a first forming element on said first member;    a second member connected with said first member, and a second forming element on said second member;    said second member being movable, upon the application to said press of fluid under pressure, toward said first member to move said second forming element toward said first forming element to compress or shape the piece of tissue between the first and second forming elements.    
     
     
         30 . A tissue press for compressing or shaping a piece of tissue, comprising: 
 a first member, and a first forming element on said first member;    a second member connected with said first member, and a second forming element on said second member;    said second member being movable toward said first member to move said second forming element toward said first forming element to compress or shape the piece of tissue between the first and second forming elements; and    a non-stick coating on at least one of said first and second forming elements to limit adhesion of the piece of tissue while it is being compressed or shaped.    
     
     
         31 . Apparatus for shaping a piece of tissue, comprising: 
 first and second relatively movable members;    a plurality of first forming elements of different predetermined shapes selectively engageable on said first member;    means for connecting a selected one of said first forming elements with said first member;    a plurality of second forming elements of different predetermined shapes selectively engageable on said second member;    means for connecting a selected one of said second forming elements with said second member;    said first and second forming elements when connected with said first and second members being positionable on opposite sides of the piece of tissue; and    said first and second members being relatively movable between a first spaced apart condition and a second condition in which said piece of tissue is shaped between said first and second forming elements.    
     
     
         32 . Apparatus as set forth in  claim 31  wherein said means for connecting comprises respective surface portions on said forming elements and said members for slidably receiving said forming elements on said members.  
     
     
         33 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into a flat shape.  
     
     
         34 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into a cylindrical shape.  
     
     
         35 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into an oblong shape.  
     
     
         36 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into a square shape.  
     
     
         37 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into a triangular shape.  
     
     
         38 . Apparatus as set forth in  claim 31  wherein said first and second forming elements include surface means for shaping the tissue into a semicircular shape.  
     
     
         39 . A method of preparing composite tissue graft material, comprising the steps of: 
 placing body tissue and at least one other element in a tissue press having forming elements adapted to press tissue approximately to the shape and size desired;    compressing the body tissue and the other element in the tissue press to form a composite tissue graft having the shape and size desired; and    controlling the pressure on the body tissue during the compressing step to minimize damage to or necrosis of the tissue.    
     
     
         40 . A method as set forth in  claim 39  wherein the body tissue is bone and the other element is tendon.  
     
     
         41 . A method as set forth in  claim 39  wherein the body tissue is bone and the other element is fibrin.  
     
     
         42 . A method as set forth in  claim 39  wherein the body tissue and the other element are multiple smaller pieces of the same type of body tissue to be compressedly formed into one larger piece.  
     
     
         43 . A method as set forth in  claim 39  wherein the body tissue is skin graft tissue and the other element is a retaining member therefor such as a retaining mesh.  
     
     
         44 . A method as set forth in  claim 39  wherein the other element is selected from the group consisting of antibiotics, bone growth enhancers, tri-calcium phosphate, hydroxyapatite, allografts and autografts.  
     
     
         45 . A method comprising the steps of obtaining fibrin as a component from body tissue and using the fibrin as an adhesive.  
     
     
         46 . A method as set forth in  claim 45  further comprising the step of compressing the fibrin prior to using it as an adhesive.  
     
     
         47 . A surgical implant made at least partially of a material which expands when it comes into contact with body fluids upon implantation into the body.  
     
     
         48 . An implant as defined in  claim 47  wherein said material is PEEK.  
     
     
         49 . An implant as defined in  claim 47  wherein said implant is a joint replacement part.  
     
     
         50 . An implant as defined in  claim 47  wherein said implant is a surgical stabilization element such as a plate, rivet, or screw.  
     
     
         51 . A surgical implant as defined in  claim 47  comprising a coating of a material which expands when it comes into contact with body fluids upon implantation into the body.  
     
     
         52 . Apparatus for maintaining tissue graft material in a compressed condition, comprising a retainer for placement around the compressed tissue graft material prior to implantation of the compressed tissue graft material in the body.  
     
     
         53 . Apparatus as defined in  claim 52  wherein said retainer is a cage.  
     
     
         54 . Apparatus as defined in  claim 52  wherein said retainer is a mesh.  
     
     
         55 . Apparatus as defined in  claim 52  wherein said retainer is biodegradable.  
     
     
         56 . Apparatus as defined in  claim 52  wherein said retainer is made of a polymer.  
     
     
         57 . Apparatus for maintaining tissue graft material in a compressed condition, comprising a retainer for placement around the compressed tissue graft material prior to implantation of the tissue graft material in the body, said retainer expanding after implantation in the body.  
     
     
         58 . Apparatus as defined in  claim 57  wherein said retainer is made of a material which is itself compressed prior to implantation in the body and which expands upon implantation into the body..  
     
     
         59 . Apparatus as defined in  claim 57  wherein said retainer is made of a material which expands when it comes into contact with body fluids upon implantation into the body.  
     
     
         60 . Apparatus as defined in  claim 59  wherein said material is PEEK.  
     
     
         61 . Apparatus as defined in claim  60  wherein said material is a desiccated biodegradable.