Source: https://patents.google.com/patent/AU669999B2/en
Timestamp: 2019-08-20 19:32:22
Document Index: 136860006

Matched Legal Cases: ['art 2', 'art 3', 'art 1', 'art 2', 'art 1', 'art 3', 'art 2', 'art.\n6', 'art.\n7', 'art.\n8', 'art.\n9']

AU669999B2 - Medullary drill head - Google Patents
AU669999B2
AU669999B2 AU70337/94A AU7033794A AU669999B2 AU 669999 B2 AU669999 B2 AU 669999B2 AU 70337/94 A AU70337/94 A AU 70337/94A AU 7033794 A AU7033794 A AU 7033794A AU 669999 B2 AU669999 B2 AU 669999B2
AU70337/94A
AU7033794A (en
1993-09-15 Priority to CH277493A priority Critical patent/CH687228A5/en
1993-09-15 Priority to CH2774/93 priority
1994-08-19 Application filed by AO Technologies AG filed Critical AO Technologies AG
1995-04-13 Publication of AU7033794A publication Critical patent/AU7033794A/en
1996-06-27 Publication of AU669999B2 publication Critical patent/AU669999B2/en
Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Synthes AG, Chur Actual Inventor(s): Christof Muller Peter Christen Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: MEDULLARY DRILL HEAD Our Ref 380680 POF Code: 44501/171481 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 11316.A65 MEDULLARY DRILL HEAD Field Of The Invention The invention relates to a drill or reamer head for bone surgery and in particular to a drill or reamer head for use in drilling the medullae of long bones.
Background Of The Invention In osteosynthetic treatment of fractured tubular bones, prior to the implantation of a medullary nail, the medullary space must be drilled or reamed out. To this end first a reamer guide or mandrel is fitted through the medullary segments of the individual bone fragments, over which a hollow, flexible drilling shaft with a solid drilling head is then fitted. A pneumatic drill is normally used to drive the drill shaft. After that a flexible shaft with replaceable heads having exterior diameters of differing sizes is inserted to do the final reaming out of the medullary space. Medullary drill heads can be attached securely onto the flexible shaft, and released from it by means of a simple coupling.
Since according to the state of the art the medullary drill heads (apart from the hollow shaft for the reamer guide which is fully occupied by the guide) are solid, during the drilling procedure a considerable metaphyseal and radial pressure is generated within the medulla of the distal fracture fragment.
Peak values for pressure of up to 1500 mm Hg can be produced.
The enormous increase in pressure causes a squeezing of the medullary fat into the transcortical vessels, which is disadvantageous to fracture healing, because the transcortical vessels are impaired in their function not only be the drilling procedure but also by the shifting of the medullary fat. Also, a pressure-induced infiltration of fat into the draining vein system may lead to fat embolisms.
In addition, the temperature rise that accompanies the drilling procedure (with peak values up to 500C) is undesirable.
Summary of the Invention According to the invention there is provided a drill head for drilling out the medulla of a tubular bone including a hollow body of revolution having a front part, a middle part and a rear part, each of the front and rear parts having an opening, the .:15 rear part having coupling means for attachment to a drill and the front and rear parts having spiral slots wherein the spiral slots are provided with a cutting edge.
An advantage of the invention, is provided by a hollow drill head which permits dispersal of hydraulic pressure in the distal fracture fragment during drilling of the medulla, thus avoiding the difficulties experienced with prior drilling devices.
-'20 Preferably, the front and rear parts have the shape of truncated cones.
T */JPO C tW1tVIORO ACQUEL'BFCceLE70337CUI. Cl,, T 0 By using a drill head according to the invention, the pressure that is engendered in front of the drill head during the drilling procedure can be dispersed backward through the openings provided for this purpose in the hollow drill head.
In the drawinQs: Fig. 1 is a perspective view of a medullary drill or reamer head according to the invention; Fig. 2 is a schematic top plan view of the reamer head of Fig. 1 indicating the angular positioning and size of the openings which are shown symbolically; V Fig. 3 is a schematic top plan view of a variant of the drill head of Fig. 2; and Fig. 4 is a schematic simplified side elevational view of the drill head of Figs. 1 and 2 indicating the inclination of an opening to the axis of the head.
Description Of A Preferred Embodiment eoeee Referring to Fig. 1 of the drawings, a medullary drill head essentially consists of a hollow body of revolution with a truncated conically shaped front part i, a middle part 2, a truncated conically shaped rear part 3 and a coupling piece 4 attached to the rear part, for releasable attachment to a flexible, drivable drill shaft (not shown). The wall thickness of the hollow body of revolution is most advantageously about 1 mm.
In front part 1 as well as the section of middle part 2 which adjoins part 1, in the shell 6 of the hollow body of revolution, three openings 5 in the form of spirally shaped slots, are placed 1200 apart; that is, as shown in Fig. 2, the angular distance a, from the same point on one slot, for example the upper tip or the center, to the same point on adjacent slots, S is 1200. In rear part 3, as well as in the adjoining section of middle part 2, approximately symmetrical with the slots in the front part, three openings 5' in the form of spiral slots, are arranged 1200 apart. As shown in Fig. 2, the slots 5, 5' extend over a sector P of about 60°-100 preferably about 80°-100 and S most preferably about 90 At their lower ends the slots in the rear part are preferably enlarged as at 11 to prevent clogging of the drill head.
As indicated in Fig. 4, the pitch angle, i.e. the angle of inclination of the helically shaped slots to the longitudinal axis of the head is from about 20 to about 400, preferably about to about 35 most preferably about Instead of the three slots displaced by 1200, as shown in Fig. 3, two slots displaced by 180 may be used.
The slots 5, 5' are configured so as to have cutting edges similar to a grater. Preferably the edges 10 which are oriented toward coupling piece 4 are raised up, for example, by bending them bac:.
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1. A drill head for drilling out the medulla of a tubular bone including a hollow body of revolution having a front part, a middle part and a rear part, each of the front and rear parts having an opening, the rear part having coupling means for attachment to a drill and the front and rear parts having spiral slots wherein the spiral slots are provided with a cufftting edge.
2. A drill head according to claim 1 wherein the cutting edges of the spiral slots are facing away from the coupling means.
3. A drill head according to any one of the preceding claims wherein the front part has the shape of a truncated cone. :15 4. A drill head according to any one of the preceding claims wherein the rear part has the shape of a truncated cone.
5. A drill head according to any one of the preceding claims wherein ihe front part includes two spiral slots extending into the middle part, about 1800 apart.
6. A drill head according to any one of the preceding claims wherein the rear part includes two spiral slots extending into the middle part, about 1800 apart.
7. A drill head according to any one of claims 1 to 4 wherein the front part has three slots about 120' apart extending into the middle part.
8. A drill head according to any one of the claims 1 to 4 or 7 wherein the rear part has three slots, about 1200 apart extending into the middle part.
9. A drill head according to any one of claims 4 to 6 wherein the spiral slots are inclined to the axis of the drill head at an angle of about 200 to about 400. JPD' WINWORUIACUE LIBFNOEL,70337CLM DOC A drill head according to any one of claims 4 to 6 wherein the spiral slots are inclined to the axis of the drill head at an angle of about 25° to
11. A drill head according to any one of claims 4 to 6 or 8 or 9 wherein the spiral slots occupy a sector of the body of revolution of about 600 to about 1000.
12. A drill head according to claim 11 wherein the sector is about 800 to about
1000. 13. A drill head according to any one of the preceding claims wherein the body of revolution includes a shell from about 0.5 to about 2mm thick. 14. A drill head according to any one of claims 1 to 12 wherein the shell is from about 0.8 to about 1.2 mm thick. i 15. A drill head according to any one of the preceding claims including openings in the front part and in the coupling part for receiving a guide wire. 16. A drill head according to any one of the preceding claims wherein at least 50% of the total volume of the body of revolution is hollow. 17. A drill head according to any one of claims 1 to 15 wherein at least 70% of the total volume of the body of revolution is hollow. 18. A drill head substantially as hereinbefore described and illustrated. Dated: 1 May, 1996 PHILLIPS ORMONDE FITZPATRICK Attorneys for: SYNTHESAG, CHUR RA'JA O E337L CC TVN 0 JPO S.''IPIP.C)JAZ.,ELI3FN0CE LE.70337CLM.CC Abstract A drill head for medullary drilling is formed as a hollow body of revolution having cutting slots in its surface. S* S. S. S SS 8
AU70337/94A 1993-09-15 1994-08-19 Medullary drill head Ceased AU669999B2 (en)
CH277493A CH687228A5 (en) 1993-09-15 1993-09-15 Drill head.
CH2774/93 1993-09-15
AU7033794A AU7033794A (en) 1995-04-13
AU669999B2 true AU669999B2 (en) 1996-06-27
AU70337/94A Ceased AU669999B2 (en) 1993-09-15 1994-08-19 Medullary drill head
AU (1) AU669999B2 (en)
CH (1) CH687228A5 (en)
NO (1) NO943416L (en)
DE102016115634B4 (en) 2016-08-23 2019-05-23 G. Michael Hess Surgical tool
RU187344U1 (en) * 2018-06-14 2019-03-01 Руслан Маратович Вахитов-Ковалевич The device for intraosseous osteosynthesis of long bones
AU2653977A (en) * 1976-03-16 1979-01-04 Nied Dr. Nied Dent. Hans Schricker Dr. Dental implant with multiple roots
AU7022591A (en) * 1990-02-02 1991-08-08 Howmedica Osteonics Corp. Surgical reamer
1993-09-15 CH CH277493A patent/CH687228A5/en not_active IP Right Cessation
1994-08-19 AU AU70337/94A patent/AU669999B2/en not_active Ceased
1994-08-20 ES ES94113033T patent/ES2142367T3/en not_active Expired - Lifetime
1994-08-20 EP EP19940113033 patent/EP0648477B1/en not_active Expired - Lifetime
1994-08-20 DE DE1994509035 patent/DE59409035D1/en not_active Expired - Lifetime
1994-09-07 CA CA 2131610 patent/CA2131610C/en not_active Expired - Lifetime
1994-09-09 JP JP24088794A patent/JP3325402B2/en not_active Expired - Fee Related
1994-09-14 NO NO943416A patent/NO943416L/en unknown
1994-09-15 FI FI944270A patent/FI944270A/en unknown
1996-01-25 US US08/599,505 patent/US5690634A/en not_active Expired - Lifetime
ES2142367T3 (en) 2000-04-16
AU7033794A (en) 1995-04-13
NO943416L (en) 1995-03-16
DE59409035D1 (en) 2000-02-03
US5690634A (en) 1997-11-25
FI944270A (en) 1995-03-16
FI944270D0 (en)
CH687228A5 (en) 1996-10-31
CA2131610A1 (en) 1995-03-16
FI944270A0 (en) 1994-09-15
NO943416D0 (en) 1994-09-14
EP0648477B1 (en) 1999-12-29
JP3325402B2 (en) 2002-09-17
JPH0779984A (en) 1995-03-28
CA2131610C (en) 2000-11-14
EP0648477A2 (en) 1995-04-19
EP0648477A3 (en) 1995-09-13
US5484438A (en) 1996-01-16 Intramedullary nail with screw-receiving solid insert
CA2360860C (en) 2008-11-04 Device for removing bone grafts
ES2208569T3 (en) 2004-06-16 intervertebral implant shaped cage.