Abstract
A surgical milling cutter designed to remove bone and/or cartilage tissue includes a shaft which extends along a longitudinal axis, can rotate about same, and can be releasably connected to a drive device and which has a proximal end that can be rotationally fixed to a drive unit and a distal end lying opposite the proximal end. A milling surface circumferentially surrounds the shaft (2) and extends on the distal end along the longitudinal axis of the shaft. The milling surface protrudes radially from the shaft and has a milling surface maximum radius. The surgical milling cutter prevents unwanted damage to delicate body structures via an atraumatic design having a protective assembly provided on the distal end. The protective assembly has a distal support surface and a protective assembly maximum radius in order to form a protective ring which surrounds the milling surface maximum radius in a circular manner.
Claims
1.-28. (canceled)
1.-26. (canceled)
29. A surgical milling cutter designed for the removal of bone and/or cartilage tissue comprising a shaft which defines a longitudinal axis and which is rotatable about an axis of rotation and which has a nominal diameter and a proximal end which can be non-rotatably connected to a drive unit and a distal end opposite the proximal end, wherein provided at the distal end is a milling head having a milling surface which circumferentially surrounds the shaft and extends along the longitudinal axis of the shaft, wherein the milling surface is delimited by a proximally disposed milling surface proximal end and a distally disposed milling surface distal end and a milling surface maximum radius (R1), wherein it is of an atraumatic configuration, the milling surface is also proximally operative, the milling surface is enlarged in the distal direction radially beyond the nominal diameter of the shaft, that a protective arrangement is provided at the distal end, the protective arrangement is provided distally from the milling surface distal end, the protective arrangement has a distal contact surface and a protective arrangement maximum radius (R2) for forming a protective ring which surrounds the milling surface maximum radius (R1) in an annular configuration so that the protective arrangement upon rotation of the milling cutter defines around the milling surface a circumferentially surrounding protective zone extending from the protective arrangement maximum radius (R2) to the milling surface distal end.
30. A surgical milling cutter according to claim 29, wherein the protective ring narrows radially outwardly.
31. A surgical milling cutter according to claim 30, wherein the protective ring is wedge-shaped.
32. A surgical milling cutter according to claim 31, wherein the protective ring includes a proximal wedge surface which includes a proximal wedge angle (.sub.1) with a straight line extending through the milling surface maximum radius (R1).
33. A surgical milling cutter according to claim 31, wherein the protective ring includes a distal wedge surface which includes a distal wedge angle (.sub.2) with a straight line extending through the milling surface maximum radius (R1).
34. A surgical milling cutter according to claim 32, wherein the protective ring includes a proximal wedge angle (.sub.1) and a distal wedge angle (.sub.2).
35. A surgical milling cutter according to claim 34, wherein the proximal wedge angle (.sub.1) and the distal wedge angle (.sub.2) are of substantially the same size.
36. A surgical milling cutter according to claim 34, wherein the proximal wedge angle (.sub.1) and the distal wedge angle (.sub.2) are of different sizes.
37. A surgical milling cutter according to claim 34, wherein the distal wedge angle (.sub.2) is negative or positive.
38. A surgical milling cutter according to claim 29, wherein the milling surface is of a conical configuration from the milling surface proximal end to the milling surface distal end.
39. A surgical milling cutter according to claim 29, wherein the milling surface includes cutting edges.
40. A milling cutter according to claim 29, wherein the milling surface is adapted to act exclusively proximally.
41. A milling cutter according to claim 29, wherein the protective arrangement maximum radius (R2) corresponds at least to the milling surface maximum radius (R1) plus the upper predetermined limit deviation plus ten times the predetermined concentricity.
42. A milling cutter according to claim 29, wherein the protective arrangement maximum radius (R2) is markedly larger than the milling surface maximum radius (R1).
43. A milling cutter according to claim 29, wherein the protective arrangement includes a protective cap which forms a distal contact surface and extends to the protective arrangement maximum radius (R2).
44. A milling cutter according to claim 29, wherein the protective arrangement includes a protective girdle which extends in the proximal direction over the protective arrangement maximum radius (R2).
45. A milling cutter according to claim 29, wherein the protective arrangement can be connected to the milling head by way of a connector.
46. A milling cutter according to claim 45, wherein the connector is adapted for releasable connection.
47. A milling cutter according to claim 45, wherein the connector includes a seat provided distally from the milling surface.
48. A milling cutter according to claim 45, wherein the connector includes a stem-mounted coupling ball at a first counterpart joint member, which can be releasably fitted into a corresponding recess having an undercut portion or a constriction at a second counterpart joint member.
49. A milling cutter according to claim 45, wherein the connector is adapted to permit relative displacement between the milling head and the protective arrangement.
50. A milling cutter according to claim 45, wherein the connector includes a screw connection.
51. A milling cutter according to claim 50, wherein the screw connection includes a threaded pin provided distally from the milling surface and which can be connected to the protective arrangement.
52. A milling cutter according to claim 51, wherein the protective arrangement includes a female thread for connection to the threaded pin.
53. A milling cutter according to claim 52, wherein the protective arrangement can be connected to the threaded pin by way of a nut and the protective arrangement includes a nut receiver for the nut.
54. A milling cutter according to claim 29, wherein the protective arrangement is of a resistance-reducing nature.
55. A milling cutter according to claim 29, wherein the protective arrangement is at least partially elastic.
56. A milling cutter according to claim 45, wherein at least the connector is elastic.
Description
[0164] FIG. 1 shows a side view of a first embodiment of a milling cutter according to the invention,
[0165] FIG. 2 shows a plan view of the milling cutter of FIG. 1,
[0166] FIG. 3 shows a cross-section of the milling cutter of FIG. 1,
[0167] FIG. 4 shows an enlarged perspective view of the milling head of the milling cutter of FIG. 1,
[0168] FIG. 5 shows a side view of a second embodiment of a milling cutter according to the invention,
[0169] FIG. 6 shows a plan view of the milling cutter of FIG. 5,
[0170] FIG. 7 shows a cross-section along line B-B in FIG. 6,
[0171] FIG. 8 shows an enlarged perspective view of the milling head of the second embodiment,
[0172] FIG. 9 shows the protective zone formed by the configuration according to the invention of the milling head, the protective zone surrounding the adjacent vulnerable tissue in the milling operation,
[0173] FIG. 10 shows an enlarged isometric plan view of the milling head of a third embodiment with the protective cap removed,
[0174] FIG. 11 shows an isometric side view of the third embodiment from below,
[0175] FIG. 12 shows an isometric side view of the third embodiment,
[0176] FIG. 13 shows a shortened side view of the third embodiment,
[0177] FIG. 14 shows an enlarged cross-section of the milling head of the third embodiment,
[0178] FIG. 15 shows an enlarged isometric plan view of the milling head of a fourth embodiment with the protective ring removed,
[0179] FIG. 16 shows a perspective view of the fourth embodiment from below,
[0180] FIG. 17 shows an enlarged cross-section of the milling head of the fourth embodiment with the fitted protective ring,
[0181] FIG. 18 shows a side view of the fourth embodiment,
[0182] FIG. 19 shows an enlarged isometric plan view of a fifth embodiment with the protective cap removed,
[0183] FIG. 20 shows an enlarged isometric view of the fifth embodiment with the protective cap removed from below,
[0184] FIG. 21 shows an enlarged lateral sectional view of the fifth embodiment with the protective cap fitted,
[0185] FIG. 22 shows a shortened side view of the fifth embodiment,
[0186] FIG. 23 shows an isometric side view of the fifth embodiment,
[0187] FIG. 24 shows a side view of a sixth embodiment with a spherical milling head and a protective girdle,
[0188] FIG. 25 shows a side view of a seventh embodiment of a milling head with flattened protective cap and protective girdle,
[0189] FIG. 26 shows an enlarged isometric side view of a milling head of an eighth embodiment with the protective cap removed,
[0190] FIG. 27 shows an enlarged isometric view of the milling head of the eighth embodiment from below,
[0191] FIG. 28 shows another enlarged isometric plan view of the eighth embodiment with the protective cap fitted,
[0192] FIG. 29 shows an enlarged cross-section of the milling head of the eighth embodiment in centred orientation of the protective cap in relation to the milling head,
[0193] FIG. 30 shows a reduced-scale cross-section of the milling head of the eighth embodiment with the protective cap in displaced orientation in relation to the milling head,
[0194] FIG. 31 shows a side view of the eighth embodiment,
[0195] FIG. 32 shows an enlarged side view of a milling head of a ninth embodiment with a flat top side on the protective ring,
[0196] FIG. 33 shows an enlarged side view of a milling head of a tenth embodiment with a disc-shaped protective ring with identical curvature on the top side and the underside,
[0197] FIG. 34 shows an enlarged side view of a milling head of an eleventh embodiment with a protective ring with an only slightly curved underside and a more greatly curved top side,
[0198] FIG. 35 shows an isometric view from below of a twelfth embodiment with a threaded pin at the distal end of the milling surface, which can be turned into a threaded opening arranged centrally in a protective ring,
[0199] FIG. 36 is an isometric cross-section of the eleventh embodiment of FIG. 35,
[0200] FIG. 37 is an isometric plan view of a thirteenth embodiment with a threaded pin which projects distally from the milling surface and on to which a protective arrangement in the form of a protective cap can be screwed,
[0201] FIG. 38 shows a side view of the thirteenth embodiment of FIG. 37 with the protective cap removed,
[0202] FIG. 39 shows an isometric plan view of a fourteenth embodiment with a protective arrangement in the form of a protective ball with a contact surface which is flattened at the top side, which can be screwed on to the threaded pin of the milling cutter, that projects distally from the milling surface,
[0203] FIG. 40 shows a side view of the fourteenth embodiment of FIG. 39,
[0204] FIG. 41 shows an isometric longitudinal section of a fifteenth embodiment with a protective cap which is closed at the front side and which can be screwed with a central threaded hole on to the threaded pin projecting distally from the milling surface,
[0205] FIG. 42 shows an isometric longitudinal section of a sixteenth embodiment with a protective arrangement in the form of a protective ring, which preferably comprises ceramic and can be fixed by way of a nut to the threaded pin projecting distally from the milling surface, wherein provided for receiving same at the distal lower end is a nut receiving means functioning as a seat for the nut,
[0206] FIG. 43 shows an isometric longitudinal section of a seventeenth embodiment with a disc-shaped protective arrangement having a threaded pin on the proximal top side, which can be screwed into a threaded hole at the distal end of the milling cutter,
[0207] FIG. 44 shows a side view of an eighteenth embodiment with a protective arrangement screwed into the threaded hole on the milling head, with a slightly convexly curved distal contact surface,
[0208] FIG. 45 shows an isometric longitudinal section of a nineteenth embodiment with a disc-shaped protective arrangement and a concavely curved distal protective surface, which can be screwed by means of a proximal threaded pin into the threaded hole at the distal end of the milling cutter,
[0209] FIG. 46 shows an isometric longitudinal section of a twentieth embodiment with a protective arrangement in the form of a protective ring, which can be screwed fast to the distal end of the milling head by means of a threaded pin which in the installation position is accommodated in a distal mounting opening in the protective ring,
[0210] FIG. 47 shows an enlarged side view of a twenty-first embodiment with a protective ring projecting distally from the milling surface maximum radius and projecting radially beyond same and which is snap-engaged on a corresponding seat at the distal end of the milling cutter,
[0211] FIG. 48 shows an isometric plan view of a twenty-second embodiment with a protective ring which is snap-engaged on to the distal end of the milling cutter distally from the milling surface maximum radius by engagement on to a seat,
[0212] FIG. 49 shows an isometric longitudinal section of a twenty-third embodiment with a protective attachment which is fixed distally to the milling surface by way of a fixing bolt with a hexagonal socket and which has a first disc-shaped portion adjoining the milling surface maximum radius of the milling surface, which forms a protective ring around the milling surface maximum radius with doubling of the outside radius thereof and which is adjoined extending distally by a protective collar of an arcuate configuration at the outward side for centrally receiving the fixing bolt, which is of a radial extent of approximately the milling surface maximum radius,
[0213] FIG. 50 shows a longitudinal section of a milling cutter according to the invention to illustrate the terms and angles used, and
[0214] FIGS. 51 to 55 show side views of the use of a milling cutter according to the invention in an operating procedure according to the invention at two cervical vertebral arches (lamina), for example a Frykholm's operation, interlaminar windowing and hemilaminectomy.
[0215] All embodiments are of a rotationally symmetrical configuration relative to the centre line of the milling cutter.
[0216] The milling cutter shown in FIG. 1 accordingly primarily comprises the shaft 2 having a top proximal end for non-rotatable connection to a known drive device and a complex milling head 4 at the front distal end which is of a complex geometry.
[0217] The milling head 4 includes a proximally oriented or operative sharp milling surface 4.1 (here with a tooth arrangement) which from the outer peripheral surface of the shaft 2 enlarges in the distal direction to a maximum periphery where there is a protective ring 4.2 surrounding the maximum periphery in an annular configuration and projecting markedly radially outwardly beyond the maximum periphery. Provided at the distal front end of a somewhat reduced radius is a distal convex protective cap 4.3 which is set back or recessed in relation to the protective ring 4.2.
[0218] As can be clearly seen the milling surface 4.1 extends only to the maximum periphery and then goes into the rounded protective ring 4.2 which surrounds that maximum periphery in an annular configuration in the form of a radial ring. In an operation that protective ring 4.2 can be pushed without causing injury into the tissue, more specifically even when the milling cutter is rotating, because the protective ring 4.2 like all other surfaces apart from the milling surface is edge-free and of a rounded configuration.
[0219] Like the first embodiment shown in FIGS. 1 to 4 the second embodiment shown in FIGS. 5 to 8 of the milling cutter is also provided with a milling head 6 of an alternative configuration, but this milling cutter is also in the form of a one-piece turned part. In this second embodiment the protective cap 6.3 however is of a convex mushroom-shaped configuration, in contrast to the first embodiment this is larger and extends continuously without a recess from the outer edge of the protective ring 6.2, whereby the protective cap 6.3 and the protective ring 6.2 therefore form a continuous segment of a ball with a larger distal contact surface than the first embodiment.
[0220] FIG. 9 shows an enlarged side view of a milling cutter introduced in an operation between diagrammatically indicated tissue 8 and bone structures 10 for illustrating the three-dimensional protective zone 12 formed by the protective ring 6.2 of the protective arrangement. That three-dimensional protective zone 12 is shown in black and is defined radially at the outside by the connecting line from the outside edge of the protective ring 6.2 or the protective cap 6.3 to the proximal end of the milling surface 6.1 and at the inside by the milling surface 6.1 itself. The rotational body of that region forms the three-dimensional protective zone 12 around the milling surface 6.1, in relation to the surrounding tissue or the bone 10, into which no tissue 8 passes. In other words: the protective arrangement is such that the protective zone 12 is always free from tissue 8 during the operation. The further the protective ring 6.2 or the protective cap 6.3 projects beyond the milling surface 6.1 or the larger the maximum diameter thereof is, the correspondingly further is the maximum periphery of the milling surface 6.1 enlarged and correspondingly larger is the protective zone formed around the milling surface 6.1.
[0221] It is possible to clearly see how the protective cap 6.3 can be applied to the tissue and thus with enlargement when applying pressure the surface pressure applied to the tissue is reduced in that way but at the same time the milling cutter can be used with its milling surface 6.1 operating exclusively in a proximal relationship in order to proximally removed the adjoining bone 10.
[0222] The protective function produced by the geometrical configuration is clearly apparent in FIG. 9. In order carefully to push aside or separate the tactile soft tissue pieces from the bone pieces 10 to be milled away and at the same time to ensure good bonding to the bone the geometry of the milling head can be mushroom-shaped in accordance with the second embodiment, in which case the distal surface of the protective cap 6.3 and the protective ring 6.2 is polished smooth or is coated in such a way that, by virtue of the protective ring 6.2, all edges are rounded off and the sharp working surface ends in proximal relationship with the lateral edge of the protective ring 6.2 before the region of the maximum radial extent.
[0223] FIGS. 10 to 14 show various views of a third embodiment of a milling cutter in which the milling head 14 is again provided in one piece at the lower end of the shaft 2 and, forming the milling surface 14.1, extends in a continuously enlarging configuration from the outer peripheral surface of the shaft 2 to a lower maximum periphery, and there goes into an upper circular plate 14.2, wherein distally spaced therefrom by way of a reduced undercut portion there is provided a lower circular plate 14.2 so that there is a peripherally extending groove between the circular plates 14.2 and 14.3. The protective cap 16 which comprises plastic with a PTFE/Teflon coating and which is of a toroidal configuration can be inserted into that groove, the protective cap being convexly curved on the proximal and distal sides, like a flying saucer. The outside radius of the protective cap 16 is approximately twice as great as the maximum radius of the milling surface 14.1 at the distal end. On the top side the protective cap 16 has an insertion opening 16.1 of corresponding configuration, with a peripherally extending, inwardly projecting elastic edge 16.2 so that the lower circular plate 14.5 can be fitted into the insertion opening 16.1 and the edge 16.2 in the installed position engages into the peripheral groove in the milling head 14 and thus connects the protective cap 16 releasably but captively to the milling head 14, wherein in this embodiment the distal end of the protective cap 16 forms the contact surface.
[0224] In the fifth embodiment shown in FIGS. 16 to 18 the milling surface 18.1 of the milling head 18 is as in the fourth embodiment, but the fixing end which is provided distally from the milling surface 18.1 is of a somewhat different configuration, more specifically with a more greatly convexly curved distal contact surface 18.3 and an undercut configuration which proximally adjoins same and which is reduced in size in relation thereto, to form the seat for the protective ring 20 which can be snap-engaged into place, which in this fifth embodiment therefore forms the protective arrangement, in conjunction with the distal contact surface 18.3. That protective ring 20 is in turn in the form of a toroidally closed ring body having a central insertion opening 20.1, the inside diameter of which is smaller than the maximum diameter of the distal contact surface 18.3 which is formed on the milling cutter in one piece distally beneath the milling surface 18.1. That configuration means that the elastic protective ring 20 can be snap-engaged captively but releasably on to the seat of the milling head 18, formed by the undercut configuration. In this embodiment the contact surface 18.3 with the protective ring 20 fitted thereon forms the distal contact surface of the protective arrangement.
[0225] FIGS. 19 to 23 show various views of the sixth embodiment with a protective arrangement in the form of a protective cap 22 in which the distal contact surface is in the form of a spherical cap 22.3. At the proximal end the protective cap 22 has a stem-mounted coupling ball 22.4 which is formed in one piece and which can be inserted releasably and captively in latching engagement into an insertion opening 24.5 of corresponding configuration at the distal front end of the milling head 24. At the distal end of the milling surface 24.1 the milling head 24 has a circular plate 24.4 forming the milling surface maximum radius of the milling surface 24.1. In the installation position that circular plate 24.4 engages into an annular seat 22.5 of corresponding configuration on the proximal end of the protective cap 22. Provided on the protective cap 22 radially outwardly and annularly surrounding the seat 22.5 is a protective ring 22.6 which projects in the proximal direction beyond the circular plate 24.4 and thus embraces same at the outside in the installation position.
[0226] FIGS. 24 and 25 show the seventh and eighth embodiments of the atraumatic milling cutter, the milling surfaces 26.1; 28.1 of which are each spherical.
[0227] In the seventh embodiment shown in FIG. 24 the milling surface 26.1 and the protective cap 26.3 are both spherical, wherein the proximal milling surface 26.1 is coated with diamonds and the distal protective cap 26.3 extends proximally upwardly beyond the maximum radius to form a peripherally surrounding protective girdle 26.4.
[0228] The eighth embodiment shown in FIG. 25 also provides that the milling head 28 is spherical at least on the proximal milling surface 28.1 and is coated with diamonds. The distal contact surface 28.3 is however flattened in relation to the seventh embodiment, and therefore involves a markedly larger radius than the proximal milling surface 28.1 of the milling head 28, but is also in the form of a smooth protective cap 28.3 which peripherally completely embraces the distal end and extends proximally beyond the maximum radius of the milling head 28 once again to form a protective girdle 28.4.
[0229] The ninth embodiment shown in FIGS. 26 to 31 primarily differs from the fifth embodiment shown in FIGS. 20 to 23 in terms of the connecting means between the protective arrangement in the form of the protective cap 32 and the milling head 30. Provided at the distal end of the milling head 30 distally from the maximum radius 30.2 of the milling surface 30.1 is an insertion opening 30.3 into which a stem-mounted coupling ball 32.4 can be releasably inserted, therefore being a coupling ball 32.4 formed in one piece by way of a stem on the proximal surface of the protective cap 32. A certain oversize of the insertion opening 30.3 with respect to the outside diameter of the coupling ball 32.4 allows a relative displacement between the protective cap 32 and the milling head 30, preferably in the region of 0.5 to 1 mm. That relative displacement permits a possible deviation in the coaxial relationship of the protective arrangement from the axis of rotation of the milling cutter and thus provides improved adaptability, in particular in tight anatomical conditions.
[0230] FIGS. 32 to 34 then show various embodiments of milling heads 34, 36, 38 with protective rings 34.2; 36.2; 38.2 which are of different configurations and which are formed thereon in one piece, and with distal contact surfaces 34.3; 36.3; 38.3, which project radially beyond the respective milling surface maximum radius of the distal ends of the milling surfaces 34.1; 36.1; 38.1. The differences here substantially concern the geometrical configuration of the protective arrangements, in particular the proximal top sides of the protective rings 34.2; 36.2; 38.2 which surround the milling surfaces 34.1; 36.1; 38.1 in a plate shape.
[0231] The embodiments of FIGS. 35 to 47 represent various embodiments in which the connecting means between the milling head and the protective arrangement are in the form of a screw connection.
[0232] The embodiments of FIGS. 35 to 42 are in the form of male screw connections, in which provided at the distal end of the milling head, being the lower end in the Figures, is a threaded pin projecting along the central axis of rotation and on to which either the protective arrangement can be directly screwed with a female thread of complementary configuration, or, in accordance with the FIG. 42 embodiment, provided at the distal lower end of the annular protective ring is a nut receiving means, therefore being a receiving opening which is complementary to the nut and in which the nut non-rotatably fits and at the same time is shielded by the surrounding protective arrangement from the surrounding tissue to prevent unintended injury.
[0233] In contrast the embodiments shown in FIGS. 43 to 46 show the female configuration of the screw connections, in which a respective threaded peg or threaded pin is provided on the protective arrangements at the top sides which are proximal in the installation position, which peg or pin can be screwed into a threaded opening of complementary configuration at the inside of the distal lower end of the milling head. The embodiment of FIG. 46 is especial in that respect because therein the connection is made by way of a separate nut which is fitted enclosed in a distal pin receiving means in the protective arrangement.
[0234] FIGS. 51 to 55 show various views to illustrate the operating procedure according to the invention using a milling cutter 40 according to the invention. The milling cutter 40 includes a milling surface 40.1 which enlarges conically continuously from the milling surface proximal end to the milling surface distal end, with spiraled cutting edges, as well as a disc-shaped protective arrangement 40.2 which approximately doubles the milling surface maximum radius at the milling surface distal end.
[0235] In FIG. 51 the milling cutter is arranged before the beginning of the intervention between an upper lamina 42 and a lower lamina 44 adjoining same. Firstly the surgeon pushes the milling cutter 40 laterally into the interlaminar gap between the upper lamina 42 and the lower lamina 44.
[0236] Then as shown in FIG. 52 the lower end of the upper lamina 42 is milled away, in which case the protective arrangement 40.2 penetrates into the interlaminar gap, with the proximal support surface and the distal contact surface of the protective arrangement 40.2 being guided at the upper lamina 42 and the lower lamina 44.
[0237] In the FIG. 53 view the lower end of the upper lamina 42 has been milled away and the milling cutter 40 can then be further pushed into the interlaminar gap in order to use the protective arrangement as a lever and to enlarge the interlaminar gap and in order then to be able to continue milling in accordance with the views in FIGS. 54 and 55.
[0238] It is to be noted that the Figures shown in the sequence of FIGS. 51 to 55 are shown on an exaggerated scale and do not reproduce the actual dimensions.
[0239] In regard to the materials it is to be noted that the milling cutter or the milling head preferably comprises high-quality steel, which can also be the case with the protective arrangements. They can however also comprise plastic, in particular polyetheretherketone (PEEK) or PTFE/Teflon. When the protective arrangement is in the form of a protective ring which is fixed to the threaded pin by way of a nut (embodiment of FIG. 42 or FIG. 46) it has proven to be particularly attractive from the economic point of view for the protective ring to be made of ceramic, being particularly easy to clean and can be used more frequently.
[0240] Embodiments provide that the protective arrangement can be deformed by virtue of the geometrical configuration, the selection of an elastic material or a combination of both, in order to be better adapted to the anatomical conditions (for example the narrow gap).
[0241] That can be implemented by selecting an elastic material (preferably PTFE/Teflon, a biocompatible type of silicone or another elastic biocompatible material) and/or the geometrical configuration of the protective arrangement itself, in particular in the region of the above-mentioned intermediate portion. That elastic deformation can involve both the external shape of the protective arrangement and also the position of the protective arrangement with respect to the axis of rotation and the milling surface maximum radius R1 in all three axes. In that respect the elasticity can occur both at the outer peripheral surface of the protective arrangement, or however also due to a partially elastic connection between the protective arrangement and the milling cutter or the seat for connecting the protective arrangement to the milling cutter, for example by the elastic configuration of the coupling means, in particular the coupling ball.
[0242] Although the proposed milling cutter is particularly suitable for surgery the milling surface which is operative exclusively proximally and the distal protective arrangement can also be used in other areas in milling technology so that protection is also claimed for same.
[0243] FIG. 50 once again clearly shows the individual geometries/radii of a milling cutter according to the invention by way of example. Therein the notations are as follows: [0244] R1: milling surface maximum radius [0245] R2: protective arrangement maximum radius [0246] r: radius of the rounded configuration at the radially outer edge at the protective arrangement maximum radius [0247] L: length of the protective arrangement [0248] : wedge angle of the protective arrangement [0249] 1: wedge angle of the proximal surface of the protective arrangement [0250] 2: wedge angle of the distal surface of the protective arrangement [0251] : profile angle of a conical milling surface
[0252] The subject-matter of the present invention involves not only the subject-matter of the individual claims but also the combination of the individual claims with each other. All features and information disclosed in the documentsincluding the Abstract, in particular the spatial configuration illustrated in the drawings, are claimed as being essential to the invention, insofar as they are novel individually or in combination, over the state of the art.
Surgical Milling Cutter
LIST OF REFERENCES
[0253] 2 shaft [0254] 4 milling head [0255] 4.1 milling surface [0256] 4.2 protective ring [0257] 4.3 protective cap [0258] 6 milling head [0259] 6.1 milling surface [0260] 6.2 protective ring [0261] 6.3 protective cap [0262] 8 tissue [0263] 10 bone [0264] 12 three-dimensional protective zone [0265] 14 milling head [0266] 14.1 milling surface [0267] 14.2 upper circular plate [0268] 14.3 lower circular plate [0269] 16 protective cap [0270] 16.1 insertion opening [0271] 16.2 edge [0272] 18 milling head [0273] 18.1 milling surface [0274] 18.3 distal contact surface [0275] 20 protective ring [0276] 20.1 insertion opening [0277] 22 protective cap [0278] 22.3 spherical cap [0279] 22.4 coupling ball [0280] 22.5 seat [0281] 22.6 protective ring [0282] 24 milling head [0283] 24.1 milling surface [0284] 24.4 circular plate [0285] 24.5 insertion opening [0286] 26 milling head [0287] 26.1 milling surface [0288] 26.3 protective cap [0289] 26.4 protective girdle [0290] 28 milling head [0291] 28.1 milling surface [0292] 28.3 protective cap [0293] 28.4 protective girdle [0294] 30 milling head [0295] 30.1 milling surface [0296] 30.2 milling surface maximum radius [0297] 30.3 insertion opening [0298] 32 protective cap [0299] 32.4 coupling ball [0300] 34 milling head [0301] 34.1 milling surface [0302] 34.2 protective ring [0303] 34.3 distal contact surface [0304] 36 milling head [0305] 36.1 milling surface [0306] 36.2 protective ring [0307] 36.3 distal contact surface [0308] 38 milling head [0309] 38.1 milling surface [0310] 38.2 protective ring [0311] 38.3 distal contact surface [0312] 40 milling cutter [0313] 40.1 milling surface [0314] 40.2 protective cap [0315] 42 upper lamina [0316] 44 lower lamina
