SE518056C2 - A surgical instrument for internal machining of holes - Google Patents

Abstract

The present invention relates to a surgical instrument (1) for internal working of holes (31) in bone tissue (30), said instrument (1) having a longitudinal direction (A) which is axial and a transverse direction (B) which is radial, and said instrument (1) comprising a first upper end (2), a first lower end (3) and an instrument shaft (4), said instrument shaft (4) having a second upper end (5), a second lower end (6), a first cross-sectional surface (C) and a first external diameter (D), with means (7; 47) which are arranged at said second upper end (5) and are inteded for cutting work, and, at said first lower end (3), with a construction for axial rotation of said instrument (1), said means (7; 47) for cutting work comprising a cutting surface (8; 48), which cutting surface (8; 48), during the internal cutting work, is partially situated outside said first cross-sectional surface (C) in relation to the transverse direction (B).

Description

518-- next wherein the dimensions of the tool vary axially to produce holes with a certain diameter at the inside and a larger diameter at the end at the mouth hole in the bone.

DESCRIPTION OF THE INVENTION We have developed a new surgical instrument for internal processing of holes in bone tissue. Through the internal processing with said instrument, holes in bone tissue can be created which holes have a diameter which is larger inside than at their mouth in the bone tissue. Said instrument comprises an instrument shaft and a cutting surface, said cutting surface, during internal cutting machining, being partly located outside a first cross-sectional area of the instrument shaft of the instrument with respect to the transverse direction of the instrument. The fact that the cutting surface of said instrument is partly located outside said first cross-sectional surface with respect to the transverse direction, enables a created hole to be widened internally and thereby holes having a larger diameter inside than at the mouth of the hole can be obtained. Holes in bone tissue that have been internally processed with said instruments have many possible applications in different areas of use. An example is when using devices for fixing an object to a hole in bone tissue, for example when using a device that we have developed. Said device, which we have developed, has a special design and can in compressed form be inserted axially into a hole and then regain normal shape in the hole if there is space when the compression ceases. When the compression ceases and the device returns to normal shape, the device can be kept engaged in the hole by the outer diameter of the device being larger than the orifice diameter of the hole. This device is suitably inserted into holes which have been enlarged internally with a surgical instrument according to the present invention as with said instruments one can create holes which have a distinct approach internally. For example, said hole may be enlarged internally in spongy bone tissue which is soft and lies within harder cortical bone tissue.

Said surgical instruments can also be used in, for example, dentistry. A small entrance hole minimizes mechanical impact on the tooth's enamel as the caries attack is mainly inside the tooth's enamel. Furthermore, said surgical instrument may be useful e.g. in the case of skeletal damage, or for the removal of unwanted tissue or foreign material which tissue / material is mainly located under cortical bone tissue.

In addition, said instrument could, for example, be used for intramedullary administration of drugs.

Said surgical instrument is thus in that in the case of internal cutting machining partly located outside a first cross-sectional area of the instrument's instrument axis with respect to the transverse direction of the instrument very useful in the enumerated applications, but also other optional and suitable applications are included in the instrument's scope. The internally machined holes that can be created with said instruments according to the present invention thus offer opportunities for new and better solutions in surgery.

The present invention relates to a surgical instrument for internal processing of holes in bone tissue, said instrument having a longitudinal direction which is axial and a transverse direction which is radial, and said instrument comprises a first upper end, a first lower end and an instrument shaft, said instrument shaft having a second upper end, a second lower end, a first cross-sectional area and a first outer diameter, said instrument comprising a means for cutting machining at said second upper end and at said first lower end being arranged a structure for axial rotation of said instrument, wherein said means for cutting machining comprises a cutting surface, which cutting surface during internal cutting machining is partly located outside said first cross-sectional surface with respect to the transverse direction.

Said orthopedic instruments may, for example, be of stainless steel or of other corrosion-resistant material and are suitably of a material with good cutting properties. Said longitudinal direction extends from the first lower end of the instrument to the first upper end of the instrument, and said transverse direction extends across said longitudinal direction. Furthermore, said first cross-sectional area suitably has a substantially circular shape.

A further embodiment according to the present invention relates to an instrument wherein said cutting surface in internal cutting machining has a first extent, which first extent is said part's largest extent, in internal cutting machining, in said transverse direction outside said first cross-sectional area. Furthermore, there is a first ratio between said first extent and said first diameter, said first ratio being at least 0.15. Further embodiments according to the present invention relate to instruments, said first ratio being at least 0.20, 0.25, 0.30, 0.35, 0.40, 0.45 or 0.50. Another embodiment according to the present invention relates to an instrument wherein said means for cutting processing comprises a cutting surface, said cutting surface being constituted by a plane formed between said first extent and a first direction which is oriented at a first angle, wherein in an embodiment according to the present invention said first angle is less than 90 ° to said first cross-sectional area. That said first angle is less than 90 ° towards said first cross-sectional surface means that said means for cutting machining is tapered towards the first upper end of the instrument.

Furthermore, said means for cutting machining may have a design which means that said instrument does not become self-feeding. Such a design according to the present invention can be achieved, for example, by said means comprising said cutting surface, which cutting surface is constituted by a plane formed between said first extent and said first direction as before, and said cutting surface comprises an outermost part having a second angle which Sia »cis-s 5 is 90 ° to said first cross-sectional area. The fact that the said instrument is not self-feeding means that unintentional extensive felling can be avoided during the internal processing.

Another embodiment according to the present invention relates to an instrument in which said first angle is less than 80 °. Furthermore, further embodiments of said instrument are meant where said first angle is less than 70 ° or 60 °. Another embodiment according to the present invention relates to an instrument in which said means for cutting machining have a first length, in internal cutting machining, which extends from said second upper end to said first upper end, i.e. from the upper end of the instrument shaft to the upper end of the instrument, there being a second ratio between said first length and said first outer diameter of the instrument shaft, which second ratio is at least 0.1.

Furthermore, instruments according to the present invention are referred to, wherein said second ratio is at least 0.2, 0.4, 0.8, 1.6 or 3.2.

Said means for cutting machining may comprise one or more of the cutting edges with the same or different cutting edges. Another embodiment according to the present invention relates to an instrument wherein said cutting surface is fixedly arranged with said instrument at said second upper end. When said cutting surface is fixedly arranged with said instrument, said means for cutting machining may have a shape which consists of modifications of cut, half round bar, prism or another geometric shape, said shape giving a large common surface with said first cross-sectional surface. A further embodiment according to the present invention relates to an instrument in which said means for cutting machining is pivotally arranged at said second upper end. This embodiment means that said means due to centrifugal force will swing out when the instrument rotates about the instrument axis. The means can be pivotally arranged by fastening the means with, for example, a pin which is placed in the transverse direction of the instrument through the instrument shaft at said second upper end and asymmetrically through the means. The attachment of the means can suitably be carried out so that a milling in the instrument shaft provides space and control for the means both in the retracted and flared position. Yet another embodiment according to the present invention relates to an instrument wherein said instrument shaft is arranged with a measuring scale. The fact that the instrument shaft is arranged with a measuring scale means that it is possible to determine how deep a occupied hole should be and at what depth in bone tissue an internal processing should be performed.

Another embodiment according to the present invention relates to an instrument in which said instrument shaft is arranged with, for example, a sleeve which is adjustable in said longitudinal direction. With the adjustable sleeve, it is possible to set the depth in bone tissue for internal processing. The sleeve has a through hole where the instrument shaft can rotate and run freely in the longitudinal direction of the instrument. The sleeve has a third upper end and from said third upper end the upper part of the sleeve extends with a second outer diameter, which second outer diameter is smaller than a hole taken up in bone tissue, and a first height, which enables said third upper end to be passed a hole in bone tissue to a depth corresponding to said first height. Said first height is equal to or less than the thickness of the cortical part of the bone tissue. By adjusting the second outer diameter, a perfect centering of the instrument shaft is achieved during internal machining.

Furthermore, the sleeve has a third outer diameter which is larger than the diameter of the hole in the bone tissue and thus the sleeve fits well with the hole. The sleeve also has a largest part with a fourth outer diameter and a second height, said largest part making the sleeve easy to grip. Due to its design, the sleeve provides good control of the instrument shaft of the surgical instrument during internal processing. When the surgical instrument is used in internal cutting processing of a heel in bone tissue, for example in internal cutting processing of the spongy part of the bone tissue, the sleeve abuts the cortical part of the bone tissue. When rotating the instrument shaft at the same time as it is pulled longitudinally, the means for cutting processing will cut the spongy part of the bone tissue. When the means for cutting processing reaches the cortical part of the bone tissue, a greater torque is required for the rotation. A larger torsional moment can be noticed by an operator who can then interrupt the internal cutting processing and measure the thickness of the cortical part of the bone tissue with a measuring scale. In the cutting operation, the sleeve centers the instrument shaft, whereby a rotationally symmetrical cavity is obtained inside the spongy part of the bone tissue. When processing is complete, the sleeve is removed from its location at the hole in the bone tissue and the surgical instrument can be removed. Another embodiment according to the present invention relates to an instrument, wherein said construction for axial rotation of said instrument comprises a handle. The handle can have a shape and / or size that facilitates axial rotation, and can be made of plastic, metal or other material that can handle the necessary cleaning or sterilization, for example autoclaving.

A further embodiment according to the present invention relates to an instrument, wherein said construction for axial rotation of said instrument comprises a fastening part for fastening in a machine. Said machine can be a manually or mechanically driven drilling machine which is driven by, for example, air or electricity. i 15 15 25 25 30 sis-css 8 Furthermore, an embodiment according to the present invention is referred to in which said instrument is autoclavable. As the instrument consists of fl your parts, all parts of the instrument can handle the necessary cleaning or sterilization, for example autoclaving.

Said instruments can be manufactured by chip-cutting machining alone, or in combination with welding or forging. Chip machining can be, for example, turning, milling or grinding.

DESCRIPTION OF FIGURES Figure 1a shows a plan side view of an embodiment of a surgical instrument according to the present invention, said instrument being shown here without both sleeve and construction for axial rotation.

Figure 1b shows a partial enlargement of a portion of the surgical instrument, 1, according to Figure 1a.

Figure 2 shows a plan side view of the instrument in figure 1a, the instrument being rotated 90 ° about the longitudinal direction of the instrument.

Figure 3 shows a plan view from above of the embodiment of the surgical instrument in Figure 1a, Figure 4 shows a side section of a sleeve, which sleeve is included in an embodiment of a surgical instrument according to the present invention.

Figure 5 shows a side sectional view of an embodiment of a surgical instrument according to the present invention and bone tissue, said instrument, which comprises a sleeve, internally processing said bone tissue, Figure 6a shows a planar side view of a surgical instrument according to the present invention wherein said means for cutting processing is pivotally arranged.

Figure 6b shows a plan side view of the surgical instrument according to Figure 6a.

Figure 6c is a partial enlargement of a portion of the surgical instrument of Figure 6b.

Figure 6d shows a plan view from above of the surgical instrument according to Figure 6a.

EMBODIMENT EXAMPLE 1a shows a planar side view of a surgical instrument, 1, having a longitudinal direction, A, and a transverse direction, B, and comprising a first upper end, 2, a first lower end, 3, and an instrument shaft, 4. The instrument shaft , 4, which here has not been drawn in its entire length, has a second upper end, 5, a second lower end, 6, a first cross-sectional area (C is not visible in Figure 1a) and a first outer diameter, D. In said second upper end, 5, is provided with means, 7, for cutting machining and at said first lower end, 3, a structure for axial rotation of said instrument, 1, can be attached. Said means, 7, for cutting machining comprises a cutting surface, 8, fixedly arranged with said instrument, 1, which cutting surface, 8, is located outside said first cross-sectional area (C is not visible in Figure 1 a), of said instrument shaft, 4, with respect to the transverse direction, B. Said cutting surface, 8, has a first length, H, in internal cutting machining, extending from said second upper end, 5, to said first upper end, 2. Furthermore, the instrument shaft, 4, is arranged with a measuring scale, 10.

Figure 1b shows a partial enlargement of the surgical instrument, 1, according to Figure 1a, which clarifies that said cutting surface, 8, consists of a plane formed between a first extent (X is visible in Figure 2 but not in Figure 1a or 1b), and a first direction, E, which is oriented at a first angle, F, towards said first cross-sectional area (C is visible in Figure 3 but not visible in Figure 1a or 1b). Said first angle, F, constitutes the cutting angle of the instrument and is here 60 °. Furthermore, the instrument, 1, has a design which prevents it from becoming self-feeding in that said cutting surface, 8, comprises an outermost part, 9, which has a second angle, G, which is 90 ° towards said first cross-sectional area (C).

Figure 2 shows a planar side view of the instrument in Figure 1a, in which the instrument, 1, has been rotated 90 ° transversely, B, and the first outer diameter of the instrument shaft, D, has also been indicated here around the longitudinal direction of the instrument, A. the instrument. Said cutting surface, 8, consists of the plane formed between said first extent, X, and said first direction, E (visible in Figure 1b), and said cutting surface, 8, comprises said outermost part, 9.

Figure 3 shows a plan view from above of the design of the surgical instrument, 1, from Figure 1a. Thus one sees the first upper end of the instrument, 2, comprising instrument shaft, 4, with its second upper end, 5, with said first outer diameter, D, and means, 7, for cutting machining, the means, 7, comprising one with said instrument, 1, fixed cutting surface, 8.

Furthermore, the part of the instrument cross-section's first cross-sectional area, C, which is not covered by the means, 7, for cutting machining is seen. Further, said cutting surface, 8, is partially located outside said first cross-sectional area, C, with respect to the cross-direction, B. Said cutting surface, 8, comprises a first extent, X, in said cross-direction, B, outside said first cross-sectional area, C, said first extent, X, is the largest extent of said cutting surface, 8, in the transverse direction, B, outside said first cross-sectional area, C.

Figure 4 shows a side section of a sleeve, 20, which is included in an embodiment of the surgical instrument. 4, the slurry 11 can freely rotate and run in the longitudinal direction, A. The sleeve, 20, has a third upper end, 22, and from said third upper end, 22, extends the upper part of the sleeve, 23, with a second outer diameter, J, (which is smaller than a current hole in bone tissue) and a first height, K, both of which enable said third upper end to be inserted into a hole in bone tissue to a depth corresponding to said first height, K .

Said first height, K is equal to or less than the thickness of the cortical part of the bone tissue. By adjusting the second outer diameter, J, a perfect centering of the instrument shaft is achieved during internal machining. Furthermore, the sleeve, 20, has a third outer diameter, M, M, is larger than the diameter of the hole in the bone tissue and thus the sleeve, 20, fits well with the hole. The sleeve, 20, also has a largest part, 24, with a fourth outer diameter, N, and a second height, P, which third outer diameter, which largest part, 24, makes the sleeve, 20, grip-friendly. Due to its design, the sleeve, 20, provides good control of the instrument shaft of the surgical instrument during internal processing.

Figure 5 shows a side section of a surgical instrument, 1, with an instrument shaft, 4, and a means, 7, for cutting processing and of bone tissue, 30, with holes, 31, said instrument, 1, comprising a sleeve , 20, internally processes a spongy portion, 32, of said bone tissue, 30. Said sleeve, 20, abuts a cortical portion, 33, of said bone tissue, 30. Upon rotation of the instrument shaft, 4, at the same time as it is pulled longitudinally the means, 7, for cutting machining, will cut machining spongy part, 32, of the bone tissue, 30. When the means, 7, for cutting machining when cortical part, 33, of the bone tissue, 30, a larger torque is required for the rotation. A larger turning moment can be noticed by an operator who can then interrupt the internal cutting machining and measure the thickness of the cortical part, 33, of the bone tissue, 30, with the measuring scale, 10. In the cutting machining, the sleeve, 20, the instrument shaft, 4, wherein a rotationally symmetrical cavity is obtained internally in the spongy part, 32, of the bone tissue, 30.

When processing is complete, the sleeve, 20, is removed from its location at the siis - oiss 12 hole, 31, in the bone tissue, 30, and the surgical instrument, 1, can be removed.

Figure 6a shows a planar side view of a surgical instrument, 1, said means, 47, for cutting machining being pivotally arranged at said second upper end, 5. Here the means, 47, for cutting machining is seen in the swung-out position. The embodiment that the means, 47, is pivotally arranged means that the means, 47, due to centrifugal force, will pivot out when the instrument, 1, rotates about the instrument axis, 4. The means, 47, is pivotally arranged in that the means, 47, is asymmetrically mounted with a pin, 40 which is placed through the instrument shaft, 4, at said second upper end, 5. Furthermore, a first extent, X, is seen in the transverse direction, B, which constitutes the largest of the cutting surface (48 is shown in Figure 6b but not in Figure 6a). the extent in the transverse direction, B, outside the first cross-sectional area, C.

Figure 6b shows a planar side view of the surgical instrument, 1, according to Figure 6a where the instrument, 1, has been rotated 90 ° about the longitudinal direction of the instrument, A and one sees a cut-out, 41, in the instrument shaft, 4, which provides space and control for the means , 47, for cutting machining in both recessed and flared positions. Here is also seen the cutting surface of the instrument, 48, Figure 6c is a partial enlargement of a portion of the surgical instrument, 1, according to fi gur 6b which clarifies that said cutting surface, 48, consists of a plane formed between a first extent (X is visible in fi gur 6a but not in 6c), and a first direction, E, which is oriented at a first angle, F, towards said first cross-sectional area, C. Said first angle, F, constitutes the cutting angle of the instrument and is here 60 °. Furthermore, the instrument, 1, has a design which prevents it from becoming self-feeding in that said cutting surface, 48, comprises an outer part, 49, which has a second angle, G, which is 90 ° towards said first cross-sectional surface, C. Figure 6d shows a plan view from above of the surgical instrument, 1, according to Figure 6a, the entire said cutting surface, 48, being visible and the first extent, X.

Claims (12)

10 15 20 25 30 519 us 14 PATENT CLAIMS A surgical instrument (1) for internal processing of holes (31) in bone tissue (30), said instrument (1) having a longitudinal direction (A) which is axial and a transverse direction (B) which is radial, and said instrument (1) comprises a first upper end (2), a first lower end (3) and an instrument shaft (4), said instrument shaft (4) having a second upper end (5), a second lower end (6), a first cross-sectional area (C) and a first outer diameter (D), and at said second upper end (5) is provided means (7; 47) for cutting machining and at said first lower end (3) is arranged a structure for axial rotation of said instrument (1), characterized in that said means (7; 47) for cutting machining comprises a cutting surface (8; 48), which cutting surface (8; 48) during internal cutting machining is partly located outside said first cross-sectional surface ( C) with respect to the transverse direction (B). An instrument (1) according to claim 1, characterized in that said cutting surface (8; 48) in internal cutting machining has a first extension (X) in said cross-direction (B) outside said first cross-sectional surface (C) and that there is a first ratio (X / D) between said first extent (X) and said first diameter (D), said first ratio (X / D) being at least 0.15. An instrument (1) according to any one of the preceding claims, wherein said cutting surface (8; 48) has a first extension (X) in said transverse direction (B) outside said first cross-sectional area (C), characterized in that said cutting surface (8; 48) is a plane formed between said first extent (X) and a first direction (E) oriented at a first angle (F), which first angle (F) is less than 90 ° to said first cross-sectional area (C). 10 15 20 25 30 518-056 '15 An instrument (1) according to claim 3, characterized in that said cutting surface (8; 48) comprises an outermost part (9; 49) having a second angle (G) which is 90 ° to said first cross-sectional area (C) . An instrument (1) according to any one of the preceding claims, wherein said means (7; 47) for cutting has a first length (H), in internal cutting, extending from said second upper end (5) to said first upper end (2) and there is a second ratio (H / D) between said first length (H) and said first outer diameter (D) of the instrument shaft, which second ratio (H / D) is at least 0.1. An instrument (1) according to the preceding claim, characterized in that said cutting surface (8) is fixedly arranged with one of said instruments (1) at said second upper end (5). 7. A characterized in that said means (47) for cutting machining instruments (1) according to any one of claims 1 to 5, is pivotally arranged at said second upper end (5). 8. A feature of said instrument shaft (4) is provided with a measuring scale (10). instrument (1) according to any one of the preceding claims, An instrument (1) characterized in that said instrument shaft (4) is arranged with a sleeve (20) according to any one of the preceding claims, which is adjustable in said longitudinal direction (A). An instrument (1) according to any one of the preceding claims, characterized in that said structure for axial rotation of according to said instrument comprises a handle. 51311561- 16 An instrument according to any one of the preceding claims, characterized by said axial construction || rotation of said instrument comprises a fastening part for fastening in a machine. An instrument (1) according to any one of the preceding claims, characterized in that said instrument can handle the necessary cleaning or sterilization, for example autoclaving.