the above object is achieved in accordance with the present invention by means of the surgical instrument shown in the attached drawings of which fig2 is a transverse section along line ii -- ii of fig1 fig3 is a transverse section along line iii -- iii of fig1 fig4 is a transverse section along line iv -- iv of fig1 fig5 is a perspective view of a portion of section b of the instrument , fig6 a is a perspective view of section a of the instrument inserted into a surgical drill , fig6 b is a perspective view of section c of the instrument inserted into a surgical drill , fig7 shows how the instrument is used to obtain a specimen of corium for transplantation , fig8 shows how the instrument containing corium is inserted under the skin for transplantation , and fig9 shows how sections a and c are broken off and the transplantation of corium is completed . referring now to fig1 of the drawings , the surgical instrument of the present invention consists essentially of a cannula open on one end comprising three sections a , b and c rigidly joined to one another . section a is tubular in shape and designed in the form of a scalpel device . its open end ( 1 ) is sharpened , and the other end is marked by an annular notch ( 4 ) in the wall of the cannula . the open , sharpened end ( 1 ) is preferably provided with a cylindrical edge . by means of a surgical drill into which the instrument can be inserted with its section a ( fig6 a ) or with its section c ( fig6 b ), it is made to rotate , thus being ready for cutting or drilling in order to sever the epidermis at the donor removal point . the advancement of the cannula takes place parallel to the surface of the skin . the centrally located section b of the instrument consists of one or several channels or shells rigidly connected to sections a and c , respectively . section b is formed as a result of the end of section b that is situated opposite section a likewise marked with an annular notch 4 &# 39 ; and comprising two or more separating seams 2 and 2 &# 39 ; ( fig3 ) extending over the entire length of section b parallel to the longitudinal axis of the cannula in the walls thereof . section b preferably comprises two separating seams 2 and 2 &# 39 ; situated on opposite sides , resulting in two half shells 5 ( fig5 ) being formed . the separating seams between the half shells 5 and 5 &# 39 ; are 0 to 0 . 5 mm wide . after the instrument has fully advanced , the tissue sample extracted in cylindrical form will be located between the shells 5 and 5 &# 39 ;. after sections a and c are broken off at annular notches 4 and 4 &# 39 ;, after the instrument has been appropriately introduced into the skin at one point and withdrawn again at another point , section b remains in the form of one or more shells separated from one another ( fig5 ) below the surface of the skin of the treated part of the body . section c of the instrument is constructed of solid material and tapers to form a pyramidal or conical sharpened needle 3 . the transition points from section a to b and from section b to c , respectively , are marked by annular notches 4 and 4 &# 39 ; in the wall of the cannula . the purpose of these notches is to indicate the end of the scalpel section a , the middle section b and section c which is made of solid material . these notches assume the form of rectangular , wedge - shaped , square or semicircular recesses in the wall of the cannula and provide the predetermined breaking points as a result of cross - sectional reduction . prior to removal of the instruments from the skin , sections a and b are broken off , so that only the tissue - filled shells 5 and 5 &# 39 ; forming the middle section b remain . by slight radial lifting and axial removal of the individual shell segments , the tissue located between the shells remains in the introduced position and is merely smoothed by trimming the ends . fig2 through 4 are , as indicated above , cross sections of the surgical instrument at various points thereof . fig5 is a perspective view of a half shell of the instrument after sections a and c have been broken off . the length of the various sections of the instrument are as follows : section a -- 5 to 20 mm ; section b -- 20 to 150 mm ; section c -- 10 to 50 mm . the preferred length of the various sections are the following : a -- 2 cm ; b -- 10 cm ; and c -- 2 cm . depending upon the intended use and the nature of the tissue to be removed , the inside diameter of the cannula may be from 1 to 20 mm . in general , a cannula the inside diameter of which is 1 . 5 mm is sufficient for performing skin transplantations . the width of the separation seams with 2 and 2 &# 39 ; which extend parallel to the axis of the cannula and form the shells of the middle section b as shown in fig5 may be 0 to 0 . 5 mm , depending on the intended use of the instrument . besides being useful for the removal and transplantation of endogenic tissue , such as corium , fat or cartilage , the instrument according to the present invention can also be employed for implanting foreign substances , that is , alloplastic material such as collagens or silicone . thus , by introducing the instrument beneath the skin of the body parts undergoing treatment , exact placement of the material is possible . the instrument is preferably constructed of stainless materials , such as stainless steel , titanium , glass or plastic . the following is an example of how the instrument of the present invention is used for the transplantation of corium . section c of the instrument is clamped into the chuck of a surgical drill ( fig6 b ). after a local anesthetic has been given at a point where corium is as thick as possible , preferably in the lateral gluteal region , and following a minimal stab incision , the instrument is advanced at low speed closely beneath the epithelium parallel to the surface of the skin ( fig7 ). the corium is excised without epithelium and fat and is deposited inside the lumen of the instrument . after sufficient corium has been deposited , the instrument is then ejected through the epithelium . the transplantation instrument containing the corium in the lumen is now removed from the drill chuck and withdrawn from the hypodermis . the material present inside the lumen of the instrument can , if desired , be compacted with either a mandrin or a larding bore needle , and the process can be repeated . in this way more material is obtained which is also compressed inside the lumen . for implantation of the recovered lumen , section a of the instrument is clamped into the chuck of the surgical drill ( fig6 a ). following disinfection , the fold or scar undergoing treatment is provided with a local anesthetic , and the tip of section c of the instrument enters the skin at the point where the fold or defect commences ( fig8 ). with the tip c rotating at low speed , the dense fibrous tissue is loosened from the terminal muscle fibers that merge into the depth of the fold . at the end of the fold the epidermis is pierced again from underneath to emerge above the skin . the drill is then disconnected from the instrument . the predetermined breaking points , that is , annular notches 4 and 4 &# 39 ;, are located outside the epidermis at both the entry and exit points of the drilling channel ( fig8 ). sections a and c of the instrument are now broken off at the predetermined breaking points 4 and 4 &# 39 ; using the fingers or two clamps ( fig9 ). the exposed half shells of section b are easily removable , leaving the implanted corium in place . while the present invention has been illustrated with the aid of certain specific embodiments thereof , it will be readily apparent to others skilled in the art that the invention is not limited to these particular embodiments , and that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims .
a surgical instrument for the removal , transplantation or implantation of corium , fat , cartilage or alloplastic material is composed of three mutually severable adjacent sections , the first of which is a cylindrical hollow scalpel , the second is a hollow tube in communication with the hallow scalpel , and the third is made of solid material which is tapered to form a sharp needle . the tubular second section has longitudinally extending separating seams to permit its separation into two half shells after the first and third sections have been severed therefrom .