BONE BIOPSY INSTRUMENT AND METHOD

• US 3,850,158 A
• Filed: 07/09/1973
• Issued: 11/26/1974
• Est. Priority Date: 07/09/1973
• Status: Expired due to Term

• Current Assignee: Elias George Elias, Youssef George Elias
• Original Assignee: Elias George Elias, Youssef George Elias
• Inventors: Elias, Elias George, Elias, Youssef George
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US05/377,652
• Time in Patent Office: 505 Days
• Field of Search: 128/2B,2R,310
• US Class Current: 600/567
• CPC Class Codes: A61B 10/025 for taking bone, bone marrow or cartilage samples

Abstract

A bone biopsy instrument comprising an obturator in the form of a rod-like member having an enlarged head at one end and a wedge shaped cutting and scraper blade at its opposite distal end slidably fitted into a tubular sheath of lesser overall length formed at its distal end to provide a conical tip converging toward the distal end to define an annular cutting edge in alignment with the passage defining wall and provided at its opposite proximal end with an enlarged head in end butting contact with the head of the obturator. The length of the tubular sheath is such that the bladed distal end of the assembled obturator protrudes from the distal end of the tubular sheath with the annular cutting edge of the tubular sheath surrounding the base of the wedge shaped cutting and scraper blade to provide an instrument the composite distal end of which may enter through a minimal length skin incision to pierce the soft subcutaneous tissue and dispose the bladed distal end of the obturator in contact with the underlying bone segment to be biopsied and permit the tubular sheath to be then advanced relative to the obturator to contact the bone severing the surrounded soft subcutaneous tissue and delimit a bone segment of finite diameter to be removed as a sample for pathological and diagnostic study. Upon removal of the obturator, the tubular sheath is rotated while applying a light axial forward pressure to advance the annular cutting edge into the bone to sever the delimited bone segment, a helical thread being preferably formed on the conical tip of the tubular sheath to feed the sheath cutting edge into the bone structure.

Claims

1. A biopsy instrument for securing optimal samples of bone for pathological and diagnostic studies comprising an elongated, tubular sheath defining a cylindrical, axial through passage, said tubular sheath at its proximal end having a head portion and at its opposite distal end having an external conical wall portion converging toward the distal end to define with the axial passage wall an annular cutting edge;

and a rod-like obturator slide fitted into said sheath passage, said obturator at its proximal end having a head portion engaging the opposed end face of said sheath head portion and a distal end protruding beyond the distal end of said sheath and comprising oppositely facing flats extending from said annular cutting edge and converging toward the distal end of the obturator to define a diametrically directed wedge shaped blade.

2. The bone biopsy instrument of claim 1 wherein the conical wall portion of said tubular sheath is provided with a helical screw thread the lead end of which is coterminous with said annular cutting edge and adapted to enter the bone outwardly of said annular cutting edge when said sheath is advanced relative to said obturator to initiate entry of said annular cutting edge into the bone and thereafter, upon rotation of said sheath, to self thread into the surrounding bone to advance the annular cutting edge into the bone and sever an annular bone segment of the desired thickness to be removed.

3. The method of securing an optimal sample of bone from human beings and animals for use in pathological and diagnostic studies using an instrument comprising a cylindrical rod-like obturator the distal end of which is formed to provide a wedge shaped cutting edge extending diametrically fitted into a cylindrical sheathing the distal end of which is externally tapered to define an annular cutting edge encircling the base circle of the wedge shaped obturator distal end, comprising the steps of making a small skin incision over the area to be biopsied;

entering into the incision the wedge shaped, cutting blade end of the obturator;

advancing the obturator and sheathing as a unit through said incision until the tip of said wedge shaped cutting blade engages the bone thereby cutting through and parting the subcutaneous soft tissue overlying the bone area to be biopsied to permit entry of the sheathing distal end;

slidingly advancing the sheathing relative to said obturator to advance the annular cutting edge through the parted soft tissue subtended by the annular cutting edge thereby severing the soft tissue within the annular cutting edge;

rotating the obturator to scrape the bone area within the annular cutting edge and free the severed soft tissue from said bone area;

retracting the obturator from the sheathing;

applying axial pressure to the sheathing while rotating the sheathing to enter the annular cutting edge into the bone to a desired depth thereby severing the bone segment within the annular cutting edge from the surrounding bone structure;

applying a rocking movement to the sheathing to free the severed bone segment from the underlying bone structure; and

retracting the sheathing through the incision with the dislodged and severed bone segment therein.

4. The method of claim 3 wherein the tapered distal end of the cylindrical sheathing is provided with a helical thread and the axial pressure is applied momentarily to the sheathing to initiate entry of the thread into the surrounding bone structure and thereafter rotation of the sheathing is continued to effect threaded self feeding of the annular cutting edge through the bone to minimize splintering of the bone and bone sample as the annular cutter completes its bone cutting action.

5. The steps of obtaining an optimal bone biopsy sample comprising the steps of making a line incision of finite lengTh through the skin layer into the subcutaneous soft tissue;

piercing the subcutaneous soft tissue to a depth inward to the bone along the full length of the incision while spreading the pierced tissue defining the sides of the incision by a wedging action to form an inverted truncated opening defining at the entrance of the incision a circle the diameter of which equals the original incision length;

severing the subcutaneous soft tissue subjacently related to said circle to the bone in a circular area to form a cylindrical opening having a diameter equal to said circular area;

removing the severed soft tissue from the bone by a rotating scraping action;

cutting through the bone by a rotating cutting action to smoothly sever in situ a bone disc biopsy sample of said finite diameter;

breaking the bone disc sample loose from the subjacent bone structure; and

retracting the intact bone disc sample from the incision.