Patent ID: 8439846

Claim:
A bone biopsy device ( 1 ) comprising: an outer cannula ( 2 ) consisting of a cylindrical hollow tube ( 20 ) having a first outer diameter (φ 1 ) and a first inner diameter (φ 2 ), said cannula ( 2 ) being provided with a mouth ( 21 ) with a sharp cutting edge ( 27 ) to section a frustule of spongy bone, said mouth ( 21 ) being a hollow cylinder having a second outer diameter (φ 3 ) and a second inner diameter (φ 4 ), the second outer diameter (φ 3 ) being equal to the first outer diameter (φ 1 ); a plate ( 4 ) mounted slidably inside the cannula ( 2 ) and provided with a semi-cylindrical portion ( 41 ) at a distal end of the plate ( 4 ), said plate ( 4 ) being constructed and arranged to be initially disposed inside the outer cannula ( 2 ) in a compact mode corresponding to an orientation of the bone biopsy device ( 1 ) during bone perforation, and a stylet ( 7 ) mounted slidably inside the plate ( 4 ) and provided with a pointed tip ( 70 ) which protrudes from the mouth of the cannula ( 2 ) to pierce a compact part of the bone, wherein said sharp cutting edge ( 27 ) of the mouth ( 21 ) has a profile with a plurality of adjacent arcs of a circle, so as to define a plurality of tips ( 28 ) able to scratch and cut the bone thus resecting a cylindrical frustule of spongy bone, and wherein said mouth ( 21 ) of the cannula has on an inside portion a narrowing ( 23 ) and said semi-cylindrical part ( 41 ) of the plate has at the distal end at least a pair of opposed circumferential sets of teeth ( 42 , 43 ) adapted to be bent radially inwards when they encounter said narrowing ( 23 ) of the mouth, so as to clasp firmly the base of the frustule previously sectioned by the cannula ( 2 ) as jaws and allow extraction of the frustule via the plate ( 4 ) whilst the cannula ( 2 ) is kept at the operating site.