Method for production of bone plates, in particular of plates for vertebral osteosynthesis

Abstract

A method for producing bone plates includes the following steps: using a sheet ( 1 ) of titanium or of titanium alloy having a thickness of 1.7 to 2 mm; determining the direction of the fibres of this sheet ( 1 ) and cutting out portions ( 3 ) of sheet ( 1 ) parallel to the direction of the fibres of this sheet ( 1 ); cutting out, from each portion ( 3 ) of sheet, bone plates or bone plate blanks ( 4 ), in such a way that a longitudinal direction of these plates or blanks ( 4 ) is parallel to the direction of the fibres of the sheet ( 1 ); curving the sheets, plates or blanks in a suitable manner and then finishing the plates or blanks ( 4 ).

1 . Method for producing bone plates, in particular plates for vertebral osteosynthesis, characterized in that it comprises the following steps:
 a) using a sheet ( 1 ) of titanium or of titanium alloy having a thickness of 1.7 to 2 mm;   b) determining the direction of the grain flow of this sheet ( 1 );   c) cutting out portions ( 3 ) of sheet ( 1 ), parallel to the direction of the grain flow of this sheet ( 1 ), sized so as to make it possible to obtain a plurality of bone plates, these portions ( 3 ) of sheet in particular being in the form of strips;   d) performing, in any order, operations d1, d2 and d3 below:   d1) shaping the portions ( 3 ) of sheet, or plates or blanks ( 4 ) obtained by operation d2, in particular by rolling or cold bending, in order to form a curvature of the portions ( 3 ) of sheet or of the plates or blanks ( 4 ) in the transverse direction and/or the longitudinal direction, in order to obtain one or several curvatures suited to the shape of the vertebrae and/or the lordosis of the vertebrae for which the plates being manufactured are intended;   d2) cutting out, in each portion ( 3 ) of sheet, bone plates or bone plate blanks ( 4 ), such that a longitudinal direction of these plates or blanks ( 4 ) is parallel to the direction of the grain flow of the sheet;   d3) piercing and, if necessary, cutting out or machining portions ( 3 ) of sheet, or plates or blanks ( 4 ) obtained by operation d2;   e) finishing the plates or bone plate blanks ( 4 ).   
   
   
       2 . Method according to  claim 1 , characterized in that the determination of the grain flow of the sheet ( 1 ) in step b) is done through a macrographic analysis of the surface of this sheet ( 1 ). 
   
   
       3 . Method according to  claim 1 , characterized in that the cut-outs of the portions ( 3 ) of sheet or of the plates or blanks ( 4 ) in steps c) and d2) are done using a pressurized water jet machine, in particular of the numerical control type. 
   
   
       4 . Method according to  claim 1 , characterized in that the transverse curvature produced in step d1 is generated by a radius of 80 mm and the longitudinal curvature is generated by a radius of 300 to 400 mm. 
   
   
       5 . Method according to  claim 1 , characterized in that, in step d2, the cutout blanks ( 4 ) comprise protruding legs ( 4   b ) allowing them to be immobilized on a suitable machine in order to perform all or some of the operations of step d3) and step e); the finishing operations of step e) then include the elimination of these protruding legs ( 4   b ) after performing the other finishing operations. 
   
   
       6 . Method according to  claim 5 , characterized in that said suitable machine is a four- or five-axis shaping machine (the three Cartesian axes and one or two axes of rotation). 
   
   
       7 . Method according to  claim 1 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in   step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).   
   
   
       8 . Method according to  claim 1 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): shaping of the portions ( 3 ) of sheet in the transverse direction and in the longitudinal direction;   step d3);   step d2);   step e).   
   
   
       9 . Method according to  claim 1 , characterized in that it comprises, after step d1 or d4, the performance of a macrographic analysis of the surface of at least one of the sides of said portion ( 3 ) of sheet, or of said plates or blanks ( 4 ). 
   
   
       10 . Method according to  claim 2 , characterized in that the cut-outs of the portions ( 3 ) of sheet or of the plates or blanks ( 4 ) in steps c) and d2) are done using a pressurized water jet machine, in particular of the numerical control type. 
   
   
       11 . Method according to  claim 2 , characterized in that the transverse curvature produced in step d1 is generated by a radius of 80 mm and the longitudinal curvature is generated by a radius of 300 to 400 mm. 
   
   
       12 . Method according to  claim 3 , characterized in that the transverse curvature produced in step d1 is generated by a radius of 80 mm and the longitudinal curvature is generated by a radius of 300 to 400 mm. 
   
   
       13 . Method according to  claim 2 , characterized in that, in step d2, the cutout blanks ( 4 ) comprise protruding legs ( 4   b ) allowing them to be immobilized on a suitable machine in order to perform all or some of the operations of step d3) and step e); the finishing operations of step e) then include the elimination of these protruding legs ( 4   b ) after performing the other finishing operations. 
   
   
       14 . Method according to  claim 3 , characterized in that, in step d2, the cutout blanks ( 4 ) comprise protruding legs ( 4   b ) allowing them to be immobilized on a suitable machine in order to perform all or some of the operations of step d3) and step e); the finishing operations of step e) then include the elimination of these protruding legs ( 4   b ) after performing the other finishing operations. 
   
   
       15 . Method according to  claim 4 , characterized in that, in step d2, the cutout blanks ( 4 ) comprise protruding legs ( 4   b ) allowing them to be immobilized on a suitable machine in order to perform all or some of the operations of step d3) and step e); the finishing operations of step e) then include the elimination of these protruding legs ( 4   b ) after performing the other finishing operations. 
   
   
       16 . Method according to  claim 2 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).   
   
   
       17 . Method according to  claim 3 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).   
   
   
       18 . Method according to  claim 4 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).   
   
   
       19 . Method according to  claim 5 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).   
   
   
       20 . Method according to  claim 6 , characterized in that comprises the following steps:
 step a);   step b);   step c);   step d1): formation of the portions ( 3 ) of sheet only in the transverse direction;   step d2);   step d3);   step d4): shaping of the plates or blanks ( 4 ) obtained in step d2) in order to form a curve in the longitudinal direction, suitable for the lordosis of the vertebrae for which the bone plates are intended;   step e).