DEVICE FOR APPLYING BONE REPLACEMENT PASTES
20170311998 · 2017-11-02
Inventors
Cpc classification
A61B17/8805
HUMAN NECESSITIES
A61B17/8816
HUMAN NECESSITIES
A61B17/8822
HUMAN NECESSITIES
International classification
Abstract
Device (1) for applying bone replacement pastes or bone cements, wherein the device (1) comprises: A) a container-like base part (4) with a first end (5), a second end (6) and a cavity (7), which defines a first longitudinal axis (3), is closed at the first end (5) and is open at the second end (6); and B) a filling piston (8) which can be inserted slidably into the cavity (7) and has a second longitudinal axis (10) and two or more hollow spaces (9) which extend through the filling piston (8) coaxially or parallel to the second longitudinal axis (10) and into which the cannula (13) of the applicator (2) can optionally be inserted.
Claims
1. A device for applying bone replacement pastes or bone cements comprising: A) a container-like base part having a first end, a second end and a cavity, which defines a first longitudinal axis, is closed at the first end and is open at the second end; and B) a filling piston that is slidably insertable into the cavity, which has a second longitudinal axis, and which has two or more hollow spaces that extend through the filling piston coaxially or parallel to the second longitudinal axis.
2. The device according to claim 1, wherein the device further comprises an applicator device, which has a cannula with a lumen, and an applicator piston that is configured to be inserted in the lumen of the cannula.
3. The device according to claim 1, wherein the cavity has a cross-sectional area Q perpendicular to the first longitudinal axis, each hollow space has a cross-sectional area q perpendicular to the second longitudinal axis, and a ratio between a sum of the cross-sectional areas q and the cross-sectional area Q is between 0.25 and 0.95.
4. The device according to claim 1, wherein the filling piston comprises more than two hollow spaces, which penetrate the filling piston coaxially or in parallel to the second longitudinal axis.
5. The device according to claim 1, wherein each of the hollow spaces has a volume v, wherein the cavity has a volume V, and wherein a ratio between the volume v and the volume V of the cavity amounts to at least 0.05.
6. The device according to claim 1, wherein the hollow spaces each have hollow space axes parallel to the second longitudinal axis, which are arranged in angles of a regular polygon located perpendicular to the second longitudinal axis.
7. The device according to claim 1, wherein the cavity perpendicular to the first longitudinal axis and the filling piston on an outside perpendicular to the second longitudinal axis have a non-circular cross-sectional area.
8. The device according to claim 1, wherein a grip is attached to the filling piston.
9. The device according to claim 1, wherein the base part is made in a funnel shape at the second end.
10. The device according to claim 1, wherein venting slots are arranged at a rear end of the filling piston.
11. The device according to claim 1, wherein the filling piston has a longitudinal section with a reduced cross-sectional area.
12. The device according to claim 1, wherein each of the hollow spaces has a diameter of at least 3 mm.
13. The device according to claim 1, wherein each of the hollow spaces has a diameter of at most 8.5 mm.
14-15. (canceled)
16. The device according to claim 2, wherein the cannula has a front end and is curved forward in an area of the front end at an angle of between 5° and 50°.
17. The device according to claim 2, wherein the cannula has a front end and wherein an area of the front end is flexible over a length of greater than 0 mm up to 70 mm.
18. The device according to claim 2, wherein the cannula has a lumen that does not have any constrictions at a front end of the cannula.
19. The device according to claim 2, wherein the cannula is opaque to x-rays, throughout or only at a front end.
20-21. (canceled)
22. The device according to claim 1, wherein the hollow spaces in the filling piston have a front end that is of a flat or concave shape.
23. The device according to claim 1, wherein the hollow spaces in the filling piston have a front end that is of a concave shape, which is deeper by 0.4 mm to 1.20 mm in an area of the second longitudinal axis.
24. (canceled)
25. The device according to claim 1, wherein the cavity has a depth T in a direction of the first longitudinal axis, wherein the filling piston has a height H in a direction of the second longitudinal axis, and wherein the height H is just as large as or larger than the depth T.
26. The device according to claim 2, wherein the cannula of the applicator device is configured to be slidably insertable into the hollow spaces of the filling piston.
27. The device according to claim 1, wherein the device further comprises a spatula including a spatula blade and a shaft.
28. The device according to claim 27, wherein the spatula blade has a base area which is geometrically similar to at least one part of a cross-sectional area of the cavity perpendicular to the first longitudinal axis of the base part.
29. The device according to claim 27, wherein the spatula blade has play relative to the cavity at the circumference.
30. The device according to claim 9, wherein the funnel-shaped second end of the base part has at least one rib on an inside.
31. The device according to claim 9, wherein the funnel-shaped second end of the base part tapers inwardly with a low angle against the cavity.
32. The device according to claim 2, wherein the applicator device does not comprise injection needles.
33. The device according to claim 1, wherein the base part further includes an outer sleeve that is connected with the second end of the base part by a flange-like broadening of the base part and which extends in a direction of the first longitudinal axis beyond the first end of the base part to a lower end of the sleeve.
34. The device according to claim 1, wherein the filling piston has a bonnet-type grip, which extends in a direction of the second longitudinal axis toward a front end over a section of a height H of the filling piston.
35. The device according to claim 1, wherein the first end of the base part has a small venting hole in an area of the longitudinal axis.
36. The device according to claim 1, wherein the two or more hollow spaces are non-conical in shape.
37. A kit for application of bone replacement pastes comprising a device according to claim 1 and, additionally, at least one more applicator device.
38. The kit according to claim 37, wherein the kit further comprises at least one filling piston.
39. The kit according to claim 38, wherein: a) the hollow spaces of a first filling piston are shaped differently as compared to the hollow spaces of a second filling piston; b) a cannula of a first applicator device has an external shape conforming to the hollow spaces of the first filling piston; and c) a cannula of a second applicator device has an external shape conforming to the hollow spaces of the second filling piston.
40-47. (canceled)
Description
[0069] These show:
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[0086] The embodiment of the device 1 according to the invention shown in
[0087] In addition, in an alternative embodiment the hollow spaces 9 in the filling piston 8 may be prismatic in form and for example have a polygonal (e.g., triangular, rectangular, trapezoidal or rhomboidal) cross-section. The cavity 7 has a depth T measured in the direction of the first longitudinal axis 3, and the filling piston 8 measured in the direction of the second longitudinal axis 10 has a height H, where the height H is greater than the depth T. At the first end 5 of the base part 4, a blade 27 is arranged, which perpendicular to the first longitudinal axis 3 has a larger cross-sectional area than the next higher section of the base part 4 and defines a support surface. Furthermore at the rear end 16 of the filling piston 8 a grip 14 is arranged. The applicator device 2 comprises a cannula 13 with a lumen 17 and an applicator piston 18 that can be inserted into the lumen 17 of the cannula 13. Optionally the cannula 13 may be slidably inserted into one of the three hollow spaces.
[0088] In
[0089] The filling piston 8 likewise comprises three plain-cylindrical hollow spaces 9, which penetrate the filling piston 8 in parallel to the second longitudinal axis 10. The hollow spaces 9 point toward hollow space axis 11 parallel to the second longitudinal axis 10 and placed in the corners of an equilateral triangle positioned perpendicular to the second longitudinal axis 10. The outer shape of the filling piston 8 is formed such that around each hollow space 9—viewed in cross-section—a lug with a periphery in the shape of a circular arc is formed, so that the hollow space axis 11 of each circular cylindrical hollow space 9 is arranged in the center of the circular arc-shaped periphery of a lug. Here the diameters of the circular arc-shaped periphery of the lugs and the hollow spaces are selected such that the wall strengths of the outer and intermediate walls guarantee adequate stability of the device 1. As is apparent in
[0090] In
[0091] In the following, examples of dimensions of the cavity 7 in the base part 4 and the hollow spaces 9 in the filling piston 8 are shown for two different embodiments of the device 1 according to the invention.
First Illustrative Embodiment
[0092] The device 1 comprises a cavity 7 of circular cylindrical form in the base part 4 and three hollow spaces 9 in the filling piston 8 (
[0093] The diameter of the lumen 17 in the cannula 13 of the applicator 2 and thus also the minimum length of the cannula 13 depends on the wall thickness of the cannula 13. Additional examples of dimensions are: [0094] the hollow spaces 9 can have lengths between 50 and 150 mm for diameters between 3 and 10 mm and lengths between 50 and 100 mm for diameters between 4 and 10 mm; [0095] the cavity 7 can have lengths between 30 and 100 mm for diameters between 5 and 50 mm and lengths between 40 and 80 mm for diameters between 10 and 20 mm; and [0096] the cannula 13 can have lengths between 50 and 300 mm for lumen diameters between 3 and 10 mm and lengths between 100 and 200 mm for lumen diameters between 4 and 10 mm.
[0097] Typically the lumen 17 has a diameter of 5.2 mm and the cannula 13 a length of 200 mm.
Second Illustrative Embodiment
[0098] A most compact arrangement of the hollow spaces 9 in the filling piston 8 can be achieved with 7 hollow spaces 9 wherein a central hollow space 9 is surrounded by 6 additional hollow spaces 9, the hollow space axes 11 of which—in a cross-sectional area of the filling piston 8 perpendicular to the longitudinal axis—are arranged in the corners of a hexagon, wherein the diameter of the cavity 7 amounts to little more than three times the diameter of a hollow space 9. The hollow spaces 9 in the filling piston 8 each have a diameter of 8 mm and thus each have a cross-sectional area q of 50.25 mm.sup.2, while the cavity 7 in the base part 4 may have a diameter of 26 mm and thus a cross-sectional area Q of 531 mm.sup.2. For a volume V of the cavity 7 of 24.5 cm.sup.3, the cavity 7 has a depth T of at least 46 mm. For a volume v of a hollow space 9 of 3.5 cm.sup.3, a height H of the filling piston 8 of at least 70 mm results. The ratio between the volume v of a hollow space 9 and the volume V of the cavity 7 then amounts to 0.14. In the case of such a tight arrangement a ratio between the sum of the cross-sectional areas q of the hollow spaces 9 and the cross-sectional area Q of cavity 7 of 0.66 is obtained.
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[0111] An additional embodiment of the device 1 according to the invention is shown in
[0112] The filling piston 8 is welded at its lower end 16 by ultrasound into a recess 34 in the cap 30. The cap 30 and the filling piston 8 form a unit for the user. Alternatively the connection between the back end 16 of the filling piston 8 and the receiver 34 in the cap 30 can also be designed as an irreversible press fit connection or an irreversible snap connection. In other embodiments the cap 30 and the filling piston 8 can also be made of one piece.
[0113] The cap 30 and the sleeve 32 are designed such that the outer shape of the cap 30 expands from the back end 16 of the filling piston 8 toward the lower end 31 of the cap 30 and the external shape of the sleeve 32 expands from the second end 6 of the base part 4 toward the lower end 33 of the sleeve 32.
[0114] The cap 30 and the sleeve 32, in an illustrative and non-limiting example, each have a cross-sectional area orthogonal to the first longitudinal axis 3 and the second longitudinal axis 10, having the shape of a bulging triangle similar to a Reuleaux triangle and a contour made up of three flattened circular arcs with rounded corners. This shape makes it possible for the cap 30 and/or the sleeve 32 on one hand to be ergonomically suited for manual use and on the other hand not to roll away if one of the parts or the assembled device 1 falls on its side surface.
[0115] When the filling piston 8 is inserted completely into the cavity 7 of the base part 4, the lower end 31 of the cap 30 lies on the second end 6 of the base part 4. The edges at the lower end 31 of the cap 30 and at the second end 6 of the cap 4 are rounded so as not to damage the user's glove. The cap 30 and the sleeve 32 have a slight widening to prevent slippage of the hand. The sleeve 32 also has a 3-dimensional structuring on its outer surface to prevent slipping of the glove.
[0116] The front end 15 of the filling piston 8 is shown, in an illustrative and a non-limiting example, as concave, wherein the concave shaped front end 15 of the filling piston 8 is indented by 0.4 mm to 1.2 mm in the area of the longitudinal axis 10. Alternatively the front end 15 of the filling piston 8 can also be made flat. Furthermore the first end 5 of the base part 4 has a small venting hole 29 in the area of the first longitudinal axis 3.
[0117] In analogy to the embodiment shown in
Intraoperative Preparation of the Bone Replacement Paste and Filling of the Applicator Device (FIGS. 1 and 5 to 9)
[0118] 1) Mixing the materials required for preparation of the bone replacement paste. [0119] The dry powder mixture is stirred with liquid using a spatula 12. This step is omitted in the case of ready-to-use products without application aids; [0120] 2) Filling the base part 4 with the prepared bone replacement paste. [0121] The prepared bone replacement paste is filled into the bottom part of the loading unit using spatula 12 (preferably using the funnel function); [0122] 3) Pressing the bone replacement paste firmly into the cavity 7 of the base part 4. [0123] The spatula blade 21 can be used to “tamp down” the compound into the base part 4; [0124] 4) Inserting and pressing the filling piston 8 into the cavity 7 of the base part 4, so that the hollow spaces 9 of the filling piston 8 are filled with bone replacement paste; [0125] As soon as all of the compound has been filled into the base part, the filling piston with the 3 hollow cylinders is manually pressed onto the base part. In this way the hollow spaces of the filling piston are filled. In such cases the cross sectional areas are likewise optimized such that the smallest possible application of force results. [0126] 5) Inserting the cannula 13 of an applicator device 2 into one of the hollow spaces 9 of the filling piston 8 filled with bone replacement paste so that the bone replacement paste present in the hollow space 9 of the filling piston 8 is advanced into the lumen 17 of the cannula 13. [0127] Preferably in this process the filling piston 8 is pressed against the base part 4 using the gripping element 14 so that the filling piston 8 is not raised by the pressure on the bone replacement paste in the cavity 7 of the base part 4. The bone replacement paste can be pushed off by slightly rotating the applicator device 2. [0128] 6) Introducing the bone replacement paste into the bone defect using the applicator device 2.
[0129] Steps 5) and 6) can be repeated as needed until the entire bone defect is filled with bone replacement paste.
[0130] One embodiment of the kit in accordance with the invention comprises, in addition to a device 1 according to one of the embodiments shown in
[0131] Although, as described in the preceding, various embodiments of the present invention exist, these are to be understood such that the various features can be used both individually and in any desired combination.
[0132] Therefore this invention is not simply limited to the above-named, particularly preferred embodiments.