US2121193A - Fracture clamping apparatus - Google Patents

Description

ilune P. G, E. HANlcKE 2,121,193 l FRACTURE CLAMPING APPVARATUS Original Filed Dec. 2l, 1952 2 Sheets-Sheet 1 BY faz/z y ATTORNEY' P'. G. E. HAN|KE 2,121,193

FRACTURE CLAMPING APPARATUS l June 21, 1938.

Original Filed Dec. 2l, 1932 2 Sheets-Sheet 2 4 l i BY ATTORNEY o the cutting of such a vlarge amount of muscular tap so as to provide a tapping anchoring means 40 Patented Junez1,193s 2,121,193- l UNITED STATES PATENT OFFICE Paul Gustav Erich Hanicke, Kansas City, Mo.

Application necemter 21, 1932, serial No. 648,225

Renewed October 27, 1937 claims. (cl. 12a- 92j My invention relates to apparatus for xing area, that is, the head of'the femur with lpart reduced fractures of bones, and a newand imof the neck and the trochanteric section of the proved method of fixing fractures ofthe neck shaft with part of the neck, which means isi'loof the femur or upper human leg bone. cated internally of the bone, and which is so The surgical neck 'of the femur being a rather constructed as to guarantee complete fixation weak connection between the shaft of the femur and complete stabilization of the entire bone. and the head portion thereof, which articulates More particularly it is a purpose of my invenwith the acetabulum forming the hip joint'is tion to provide a device for the internal fixation subject to frequent and dangerous strains. and of the bones by the use of compression means,

o shocks due to sudden falls or 4other sudden. jerks which Aholds them in close unity and exerts pres- 10 to the hips. In elderly or old persons such sudsure on the fractured portions of the bone toward den shocks or strains usually result in a fraceach other. ture of the neck of the femur. This type of frac- My improved apparatus also includes means ture has been treated by innumerable methods, to prevent rotation of-the head of the femur t5 but the results are not uniformly successful and around its axis relative to the neck of the femur 15 are frequently very disappointing. The purpose tofprevent separation and shifting of the fragof all the methods of 4treatment is to get a union ments. l

of the fractured bone as soon as possible. This It is a further purpose of my invention to prois only possible when bothv fracture sites are vide a device of the above mentioned character,

brought into close contact withv each other and which will permit of impaction of the bone after 2Q held firmly for a certain length of time.- Thev the compression means has been applied, and proper union of the fractured bone also depends which will permit further adjustment thereof largely upon the constitution of the patientand 'so as to press both parts of the bone tightly to whetherv the bone'cells regenerate and form new gether after such impaction, and retain the same 5 bone tissue around the fractured area.V Therleg in such engagement for a suflicientlength lof 25.

has to be kept from contracting, from inward time for a firm union of the vparts to be accomand outward rotation, as well as adduction and plished. abduction and other dangerous movements, which One of the mostimportant features of the usually cause complete dislocation Vand permainvention is the provision of a combination an- I nent deformity of the hip, resulting in what is choring device and coupling device and headed 30 known as a marked limb, etc. .In order to immember vcooperating therewith so that the anmobilize both the hip and the leg, extensive plaschoring member and the headed member operter-of-Paris casts or splints or braces have been ate tofirmly clamp the parts of the bone toapplied in previously used methods, but with a gether, said anchoring member comprising a porsmall number of good results, the possibility of tion having a coarse thread of steep pitch and 35 any satisfactory result at all depending largely a portion of smaller diameter than said coarsely on the patients condition. lTreatment of such Y threaded portion, having a fine thread of relaa fracture has also been tried by open reduction, tively much smaller pitch, the coarsely threaded which, due to the 'large incision necessaryand portionbeing so constructed that it serves as a I tissue, as well as the method of fixation used ffor threading into the bone that will be held after exposure of the bone, proves to be such a firmly vin place against axial movement after begreat shock to the patient as to be unsatisfactory ing threaded into position. By using the fine in most Casesi v thread of much less steep pitch than the tapping It is a purpose of my invention to avoid the anchoring portion for connecting the headed 45 difficulties encountered by the previous methods, member with the anchoring member, said headed of attempting to rmlystabilize a fractured bone member may be threaded on the anchoring memof the above mentioned character, by accurate ber without tending to turn the tapping an.

means and facilities and to accomplish this withchoring portion thereof in the thread formed outI the use of the extensive plaster-of-Paris thereby in the bone, and thus the head of said casts, and also without the necessity of a major headed member engaging the outer face of the operation causing shock to the patient and necesfemur at the incisionwill serve toV draw this porsitating large incisions in the leg'of the patient. tion of thefemur toward the head thereof to It is particularly a purpose of my invention vcause a close engagement between the fractured to lprovide means for immobilizing the fractured surfaces as said headed member is rotated by a 55 anchoring member in the bone, and it is also a purpose of my invention to provide suitable means for limiting the turning of the anchoring member during the tapping operation beyond the /point at which the thread has reached the extent it has been previously determined is the most desirable. This is determined by X-ray, and before the tapping is done an opening is drilled vthat will be coaxial with the thread that is subsequently tapped. The drilling means is also provided with suitable means for limiting the inward movement thereof, and my invention also contemplates the provision of suitable means for withdrawing the entire device, should the bone in which the thread is tapped be found to be of such a quality that the thread will not hold, or to remove the anchoring member after it has served its purpose, even though a break should occur in the finely threaded portion thereof, or in case such a break should occur in the finely threaded portion thereof during the operation of placing the same in position or during the operation of tightening down the threaded member thereon.

Other objects and advantages of my invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or described, except asV v Fig. 2 isa view partly in longitudinal sectionl and partly in elevation of my improved clamping andcompressing means.

Fig. 3 is a face view of the head portion of the headed element of said clamping means.

Fig. 4 is an end view of the anchoring element as viewed from the entering end thereof.

Fig. 5 is a side elevation of the drill and stop means therefor used in carrying out my improved method.

Fig.'6 is a view partly in elevation and partly ln section of the wrench used for tapping a thread with lthe anchoring member and inserting the anchoring member in position in the bone, and showing the stop` element -separate from the wrench. Y

Fig. 7 is a view in side elevation showing the wrench in engagement with the tapping anchoring member in the relationship which the same assume in the thread tapping operation of placing the anchoring member in position, and showing the stop means in engagement with the wrench.

Fig. 8 is a view similarito Fig. 6 of the tool of the nature of a screw driver used for threading the headed member on the anchoring member, and also for removing the headed member from the anchoring member, showing the headed member separated from said tool.

Fig. 9 is a view showing the screw driver-like tool in elevation as viewed substantially at right angles to Fig.V 8, and showing the same in engagement with the stop means on the anchoring member for rendering the tool inoperative.

Fig. 10 is a fragmentary sectional view similar to Fig. l, showing the impacting member in operative position and the hammer used in conjunction therewith.

Fig. 11 is a view partly in elevation and partly. in longitudinal section of the apparatus for removing a broken anchoring member from the bone, and showing the elements thereof comprising the removing tool and the coupling member for engagement by said tool spaced from each other and spaced from the broken anchoring member with the parts in the relative position they Would assume just prior to connection with each other.

Fig. 12 is a view in side elevation of a removing tool for removing the clamping means as a Yunit in case the anchoring member fails to hold,

and

Fig. 13 is an elevational view taken at right angles to Fig. 12, showing the removing tool in engagement with the head of the headed element diagrammatically, the headed element being partly broken away.

Referring in detail to the drawings, my irnproved apparatus comprises a clamping or compressing device comprising a pair of elements, Which are screw-threadedly connected together. One of said elements may be referred to as an anchoring element 20, and the other as a headed element 2|. The anchoring element comprises a combined anchoring and tap portion 22 and a threaded stem portion 23, the threaded stem portion 23 being of materially smaller diameter than the tap or anchoring portion 22. The tap or anchoring portion 22, as will be evident from Fig. 4, is made upA of a plurality of spaced cutter blades 24, which are spirally arranged and which have a steep pitch, and which are also spaced a substantial distance apart so that the same will cut acoarse thread of steep pitch.

In order to leave as much of the bone as possible the forward or entering faces of the cutter blades 24 are only inclined relative to the axis of the device as indicated at 25, while the rear faces 26 of the cutter blades are substantially 1 perpendicular to said axis at all points, the thread thus cut being a spiral that instead of being V-shaped in cross section, as is the case with an ordinary screw thread, have a cross section that is substantially only half of a V, that is, the rear face of the thread at any cross section through the same is substantially perpendicular to the axis of the thread, while the forward face is inclined in a similar manner to that in which both ofthe faces of a V-shaped thread would be.

The angularity of the inclined face to the substantially perpendicular face is made as acute as it can be so as to still have suflicient strength in the metal of the tapping portion to prevent breakage thereof. 'I'his leaves a maximum thickness of the bone between each turn of the thread cut in the bone and the next adjacent turn. The entering end of the anchoring member 20 is rounded, as at 21, to provide a reduced cutting portion thereon gradually increasing ln diameter from slightly greater than the shank portion 28 of the tap to the diameter of the cutter 'sleeve-like body portion,

- blades 24. The stem portion 23 is also threaded.

polygonal axial projection or head 29 thereon, which'is smaller in diameter than the threaded stem portion 23 and may be of any suitable shape to engage with a suitable Asocket of similar shape on a wrench member to be described below, which is shown as being square.

Cooperating with the anchoring member 2|) is the, headed member 2|, which has a tubular which is internally threaded with a thread corresponding in size and pitch to the thread provided on the stem 23, and I which has the head 30 thereon, which is provided with a transverse slot 3| therein on the outer face thereof, and which has a rounded top face 32 and a curved wall portion 33 connecting with the sleeve-like body portion of said member 2| and a rounding peripheral edge 34 joining the top face 32 and the curved portion 33 in a smooth curve so that there are no sharp projections thereon. All edges are rounded even at the points where the bottom of the slot 3| joins the peripheral wall of the head, as shown at 35. The corner 31 at the junction of the side wall of the sleeve-like portion l2| and the end edge thereof is also rounding, these edges being all rounded to prevent all possibility of injury to the patient in the use of the device. An opening 38 is provided in the headed member, running from the internally threaded opening 38 in the sleeve-like member to the slot 3| so as to provide a passage between said threaded opening 39, and said Referring now to Fig. l, it will be noted that a portion of the femur and lilium of the patient having the fractured neck portion of the femur is shown therein, and some of the surrounding esh and bone, more orless diagrammatically, to indicate the manner inf which my improved apparatus is used and for the explanation of the method of xing the fracture devised byme. In said figure the head of the femur is indicated by the numeral 40, the socket portion of the ilium in which the head 4|) operates is indicated at 4|, and the broken neck portion is indicated by the numeral 42, the fractured faces\of the bone or sites of the fracture are indicated by the numerals 43 and`"44the tissue and flesh overlying the femur at thepoint where the incision is made is indicated diagrammatically at 45, andjthe .incisionis shown at 46.

In carrying out the method the patient 4should be placed on an operating table, a fracture table cf the Albey type being preferred. Both legs are abducted as much as possible and thoroughly inverted. Care has to be taken not tobe guided by toeing in of the feet alone, but the patella or Y knee cap points markedly toward the inner side.

This places the neck of the femur in a sub-V this purpose, accuracy is highly essential to obtain a neat and clean result.v The patientV is,

placed on an all aluminum spica box with a crotch `post. The pelvic plate of the table above referred to is lowered sufliciently to allowv the X-ray pictures to be taken, when the cassette must be placed under the hip, without moving the patient. The i patient should not be moved for any reason after the iirst X-ray and the following X-ray pictures are taken. The lateral pictures to obtain the horizontal angle of the fractured neck of the femurand its position are taken diagonally through the hip from above the crest of the ilium toward the perineum.4 The patient may have to be manipulated and the fracture reduced to its normal position by manipulation thereof during observation by means of the fluoroscope. Either a local or 4straight anaesthetic can be given. An incision of from 2 to 3 inches is made taking the gluteal ridge as a guide.` Starting 1 inch below this point and l/fg inch from the anterior margin/ ofthe femur a guide wire, known as aA Kirchner wire, is drilled into the femur in a direct transverse plane toward the head of the femur, theA length of the wire being such that it'extends Well into the head portion 40 and will project a substantial distance outwardly from the exposed face 41 of the femur at the incision 46, this Wire being indicated by the numeral 48.

. `Another wireA 49 of substantially the same length as the wire 48 is then drilled in a substantially parallel direction to the wire 48 at a point about l'inch below the first wire, these wires 48 and 49 drilling their own openings in a well known manner. The wires 48 and 49 are of `such length that they project about 'l1/ inches outwardly` beyond the exposed face of the bone. A 'small marker may be attached to each wire to identify the same in the X-ray pictures, which are taken subsequent to the insertion of these wires. Anterior, posterior and lateral X-ray pictures are now taken; ShouldI the wires 48 and 49 be found to be in unsatisfactory places after taking these X-ray pictures, new wires are used and the others withdrawn. The wires 48 and49 serve as line markers and guides and as pins for temporarily xing the head of the femur relative to the shaft thereof 'so as to prevent turning of the/head around on its own axis when the apparatus for clamping the two parts of the fractured neck of the femur is inserted. After the exact angle of the neck and the exact location of l the fracture are determinedA from these X-ray pictures, the length of the neck of the femur, that is from about inch inwardly from the 'anterior face 36 of the head 40 to the outer face 41 of the cortex, is then measured from 'these pictures, the distortion being calculated carefully so that the exact length thereof is positively determined. A ychart of magnification is preferably used for this purpose. lIn this manner the distance that the. drill, which is to be used to provide the-opening for the clamping apparatus, is to enter the bone can be positively determined, so that the opening that is drilled will enter sufciently into the head of the femur to firmly anchor the apparatus in position,\but will not approach dangerously' close to the anterior face 36 of said head portion. A

For drilling this opening or passage the drill 50 is used. VThis drill is an ordinary metal drill, such as is used for aluminum having a dove-tail point 5|. 'I'he drill preferably is of a size to drill .curved X-ray cassette holder incorporated in the -erably about 1% of an inch less, than the disa hole 1A inch in diameter and is provided with a stop member, which is made up of a tapered sleeve-like member 52, having a knurled flange 53 thereon, which member is slotted at a plurality of points, as indicated at 54, and which is externally threaded to be engaged by the internal threads on the knurled nut 55.

It will be obvious that the stop member 52 can be adjusted to any position on the drill 58 desired, and the nut 55 screwed up toward the head 53 to firmly clamp thevstop member 52 in adjusted position. The stop member 52 is placed in a position on the drill 50 such that the hole drilled thereby will be of a depth fig of an inch greater than the distance from the outer face 41 of the femur at the incision to the extreme forward end of the'tap member 2U when in final position in the bone.y This adjustment is made in order that the anchoring screw or tap portion of the anchoring member at its forward end or entering end 21 will not beinserted to the end of the hole.

In drilling the main hole with the drill 50 the drill is guided by the projecting wires 48 and 49, and is directed toward the presumed location of the head of the femur as determined from the X-ray pictures. A drill with a dove-tailed center point is preferably used to prevent splintering of the bone. It may be either driven by hand or electrically, the speed preferably being about 500 revolutions per minute. The drill is pulled out gently as soon as the control stop reaches the outer face of the bone 41. Y

The anchoring member 20. is next inserted in position. This is done by means of a wrench 56 having a cross piece 51 thereon serving as a handle, the handle portion being preferably made of round rod and has rounded ends, while the shank portion of the wrench 56 is also made of round vrod or similar material and has a rounded end at 58, and is gradually tapered at 59 to the diameter of the reduced forward end portion 60 thereof, which is provided with a socket 6| therein, which has a polygonal bottom portion 62 corresponding in shape to'that of the hea`d portion or projection 29 on the anchor member20.

The portion 60 of the shank of the Wrench is made of substantially the same diameter as the drill 50 so as to be freely rotatable in the opening drilled in the bone by means of the drill 50. The

`control stop 5'2, previously described, is again utilized to limit the inward movement of the tap and wrench at the desired point so that the stop 52 will engage the'outer face 41 of the exposed portion of the bone at the incision when the anchoring member has reached the desired final position therefor, this being determined by previous measurement, the stop being preferably set on the reduced forward portion 60 of the shank of the wrench in such a position that with the projection or head 29 seated in the polygonal bottom 62 of the socket 6| the distance from the forward face of the stop 52 to the extreme forward or entering end of the tap member on the anchoring member 20 will be slightly less, preftance from the forward end of the drill to said stop member 52.

The opening or passage drilled by the drill 5!) is indicated by the numeral 63 in Fig. 1 and is of uniform size throughout, except for the small projection 84 formed at the forward end thereof or inner end thereof by the dove-tail point 5| on the drill. In inserting the anchor member 28 in the bone the anchor member 20 is pushed into the socket of the wrench and lodges itself in the polygonal portion 92 thereof firmly. This makes the anchor member and the socket wrench operate'substantially as a unit, which can be handled readily with one hand. Care 'has to be taken to start the anchoring member 20 straight into the bone and it can be readily guided by the two guide wires, or Kirchner wires 48 and 49, and the direction determined therefrom to maintain the cor' rect angle for the location of the head of the femur as determined from the X-ray pictures.

The cutting teeth 24 of the tap portion of the anchoring member 20 will cut a thread in the wall of the previously drilled passage 63 in the bone, this thread being indicated by the numeral 65. The extent of the thread tapping operation is determined by the position of the stop member 52 and the position of the anchor member 20 is also determined thereby, as theinward movement of this member and the extent of the thread cut thereby is limited by the engagement of the stop member 52 with the exposed face 41 of the bone. A screw threaded connection having thus been established between 'the bone and the anchoring member 20, the wrench can be readily removed by merely pulling outwardly thereon.

'I'he headed member or cap member 2| is next inserted. The external diameter of the tubular sleeve-like portion of the member 2| is such that it will readily pass through'the opening or passage 63 made by the drill'without any danger of binding, and While the thread 65 extends over the entire portion of the opening that has been drilled in which the tubular portion of the member 2| is located when in its final position, this is immaterial as far as the operation of the apparatus is concerned. The headed member 2| is inserted by hand first, making contact with the rst few turns of the threaded stem portion 23 of the member 20. This is done by hand so that the operator can feel the engagement of the threads to make sure that the internal thread on the member 2| is engaging with the external thread on the member 23. n

A tool for turning the headed member 2 I, which tool is shown in Figs. 8 and 9, is next utilized. Said tool is provided with a shank portion 66, which is substantially'circular in cross section and which has a handle portion 61 also made of material substantially circular in cross section, and the ends of the handle portion B1 and of the shank portion 86 are preferably rounded in a similar manner to that of the wrench 56. The

shank portion v68 is provided with flattened converging faces 68 that form a substantially flat narrow blade portion 69 similar to that of a screw driver, from which a rounded projection 10 extends in a forward direction, the diameter of the projection 10 being slightly less than that of the opening 38 in the headed member 2|, and the thickness and width of the blade portion 68 being such asto nicely fit the slot 3| in the head 30.

"The relativeposition of the member 2| and the screw driver-like tool is shown in Fig. 8 just prior to insertion of the tool vinto engagement with the head of the member 2|; With the forward. edge of the blade 68 seated in the bottom of the slot 3| and the'p'rojecton 10 in the opening 38 and extending into the passage of larger diameter within the member'2l having the internal threads 39, the tool is in position for rotation of the sleeve-like headed member 2|, and the length of the stem portion 23 and of the tubular portion of the member 2| is preferably such that the head will engage the outer surface 41 of period of time before the sleeve-like member 2| has been screwed down tight on the member 23. Should an error be made in calculations and should the person carrying out the method tighten the sleeve-like member down on the stem 23 until it reaches substantially the limit of rotation thereon, the actual reaching of this limit of rotation is prevented due to the fact that the polygonal projection 29 on `the stem 23 will reach such a position in the member 2| that it will engage' with the forward projection on the tool to force the'same out of the slot 3|, as shown in Fig. 9, so as to disengage the blade 69 of the tool'from the slot 3| to warn the operator that further rotation. of the sleeve-like headed member 2| must not be attempted, as such further rotation might cause the members and 2| to turn together and the thread to be cut deeper than intended, possibly causing breakage of the member 2U due tothe fact that the tap-like portion 22 thereof will strike the end of the drilled opening 63.

While it is possible that the two fractured surfaces 43 and 44 can be drawn into such intimate contact by means of the headed member 2| and the anchoring member 20 that no further steps may be necessary in the method of fixing the fracture, preferably the bone is impacted in the manner shown in Fig. 10. After the clamping member is in position, as shown in Fig. 1, the wires 4i* and 49 are withdrawn ahd the impactor 1| having a head portion 12 thereon, which is adapted to be engaged by a hammer 13, and havouter surface 41 of the bone, surrounding the headed member 30, andthe bone is impacted by means of said impactar 1| and the hammer 13 to force the broken surfaces 43 and 44 into snug engagement. After such impacting has been done the internally screw-threaded headed member 2| ris tightened up on the externally threaded memimpacting and tightening up of the clamping member may be repeated, should it be found necessary. f L

This completes theoperation and the clamping means remains in position for the required length of time for the surfaces 43 and 44 of the bone to knit together. The members 2|) and 2| are made out of stainless steel, and -the screw driver-like tool and the wrench can also be made out of stainless steel if desired, although the thing of greatest importance is that the clamping member, which remains in the bone for a considerable period of time, be made o f such non-corrosive material. When the two broken portions of the neck/of the femur have again firmly grown together the clamping means is removed by first unscrewing theheaded member 2|, after which the wrench 56 can' be utilized to unscrew the screw-threaded. member 2li from the screwthreaded opening in the bone by reverse rotation thereof, th`e screw thread being a right-handed thread so that the rotation of the tool during the4 thread tapping action of said member 20 is in a clockwise direction. while during the removal the rotation of the tool is in -a counter-clockwise direction.

It might sometime .happen that during the removal of the anchoring member 20 from the bone,

or during the insertion thereof, breakage thereof occurs in the relatively small finely threaded portion 23, and in Fig. 11 such a broken member 20 is shown, together with the apparatus for removing the same from the bone, said means comprising a sleeve 16 having a knurled flange 11 on one end thereof, and having an internally screwthreaded passage 18 extending entirely therethrough, said screw-threaded passage 18 being of the same pitch and size as the thread on the externally threaded stem portion 23 of the member 20, and a wrench-like member 19 having a transversely extending handle member 80 and `anexternally screw-threaded elongated shank portion 8| cooperates with the sleeve-like member 16 to remove theineii'fbei:l 20 from the bone.

The sleeve-hkenjieinber 16 istturned down on the externally .threaded portion 23 of the member `2|) until iti'eaohes the end of the thread on said externally threaded portion 23, which makes 'a thread tapped therein will not hold the anchoring member in fixed position and when this is the case the only thing that can be done is to remove the entire device comprising the anchoring member 20 and the sleeve-like member 2|.

An extracting' tool for this purpose is shown, which has a shank 83, which is provided with converging faces 84 and 85 to provide a wide end thereon, which is bifurcated to provide a pair of curved hooks 86 with a slot 81 therebetween of suflicient size to receive the tubular body portion of the member 2| with the head 38 seated on the concave side of the curved portions 86. This is shown in Fig. 13. The curved hook-like members can be inserted under the head 30 by unscrewing the Vsleeve-like member 2| suflicientlythat such insertion can be made between the outer face of the bone and the head 30 and the entire clamping means comprising the members 2|) and 2| can be withdrawn by an outward pull on theextracting tool by means of the cross handle 88.

1. An apparatus of the character described comprising an elongated member having an elongated thread tapping holding portion of substantially uniform diameter-from end `to end and a reduced threaded portion thereon and a tubular, headed member having a threaded portion adapted to engage the threaded portion of said elongated member.

2. An `apparatus of the character described comprising an elongated member having a thread tapping holding portion. a reducedthreaded portion -extending endwise from one end of 'said thread tapping holding portion and Awrench receiving means formed on the end thereof and a tubular, headed member having a threaded portion adapted to engage the threaded portion of said elongated member and receive said wrench receiving means therein.

3. An apparatus of the character described comprising an elongated member having a thread tapping holding portion and a reduced threaded portion and a tubular, headed member having a threaded portion adapted lto engage the threaded portion of said elongated member, and having a transverse groove in the head thereof intersectingthe passage in said tubular member.

4. An apparatus of the character described comprising an elongated member having a thread tapping holding portion, a reduced threaded portion and wrench receiving means thereon and a tubular, headed member having a threaded portion adapted to engage the threaded portion f said elongated member, and having a transverse groove in the head thereof intersecting the passage in said tubular member.

5. Means for clamping the broken surfaces of a bone in intimate contact comprising a member having means thereon for anchoring itself against longitudinal movement in said bone at one side of the break therein and a headed member mounted for longitudinal movement in an opening in said bone on `the othery side of Isaid break with the head thereon outermost and engaging the outer surface of said bone, said members being telescopically related and having cooperating threaded means thereon adapted to draw said members together.

6. An apparatus of the character described comprising an anchoring member having a tap portion provided with a plurality of spirally arranged cutter blades each having an inclined forward face and a rear face substantially perpendicular to the axis of said tap portion, said tap portion being of greater diameter than any other portion of said anchoring member, a threaded stem portion of smaller diameter ythan said tap portion and a polygonal formation on said stem portion adapted to be engagedv by a wrench.

7. An apparatus of the character described comprising an anchoring member having a tap portion provided with a plurality of spirally ar ranged cutter blades each having an inclined forward face and a rear face substantially perpendicular to the axis of said tap portion, said blades being widely spaced axially of said tap portion and being of steep pitch, said tap por-4 tion being of greater diameter than any other portion of said anchoring member, a threaded stem portion of smaller diameter than said tap portion, the thread on said stem portion being much finer and of much less pitch than the thread formed by said tap portion and a polyg onalformation on said stemportion adapted to be engaged by a wrench.

8. An apparatus of the 'character described comprising an anchoring member having a tap portion provided with a plurality of spirally arranged cutter blades each having an inclined forward face and a rear face -substantially perpendicular to-the axis of said tap portion, a threaded stem portion of smaller diameter than said tap portion and a polygonal formation on said stem `portion adapted to be engaged by al wrench, -and an internally threaded sleeve-like.'

member having an axial opening through the same from end to end, and having a head on one end thereof, the internally threaded portion of said sleeve-like member engaging the threaded stem portion on said anchoring member. g

9. An apparatus of the character described comprising an anchoring member having a tap portion provided with a plurality of spirally ai'u ranged cutter blades each lhaving an inclined forward face and a rear face substantially perpendicular to said axis of said tap portion, said blades being widely spaced axially of said tap portion and `being of steep pitch, a threaded stem portion of smaller diameter than said tap portion, the thread on said stem portion being much finer and of much less pitch than the thread formed by said tap portion and a polygonal formation on said stem portion adapted to be engaged by a wrench, and an internally threaded sleeve-like member having an axial opening through the same from end to end, and having a head on one end thereof, the internally threaded portion of said sleeve-like member Aengaging the threaded stem portion on said anchoring member, said head having a transverse groove therein intersecting the axial passage in said sleeve-like member. v

10. Apparatus for clamping two portions of a fractured bone together comprising an anchoring member having a tap portion, a threaded stem portion of smaller diameter than said tap portion and a polygonal formation on said stem portion, and a wrench engaging said polygonal formation, said wrench having an elongated tubular shank portion of substantially uniform diameter smaller than said tap portion 4embracing said threaded portion and a stop member of larger diameter than Said tap portion adjustable on said shank portion to limit the forward `movement of said tap portion in the bone.

11. An apparatus of the character described comprising an anchoring member having a coarsely threaded portion of steep pitch adapted to tap its own thread in a bone, a finely threaded stem portion of smaller diameter than said coarsely threaded portion, and a polygonal end portion of smaller diameter tha'n said 'nely threade'dportion, and a sleeve-like headed member having an axial passage therethrough threaded to receive said stem portion, said head having a tool receiving slot therein, said stem portion being of such length relative to said sleeve-like member that said polygonal end will reach said slot before said sleeve-like member has been screwed onto said stern to the limit of the thread thereon.

A12. An apparatus of the character described comprising an anchoring member having a coarsely threaded portion of steep pitch adapted to tap its own thread in a bone,ja finely threaded stem portion of smaller diameter` than said coarsely threaded portion, and a polygonal end portion of smaller diameter than said finely threaded portion, asleeve-like headed member having an axial passage therethrough threaded to receive said stem portion, said head having a tool'receiving" slot therein, and a tool having a flat, narrow blade adapted to engage said slot to turn said sleeve-like member and provided with a centralv forward projection, entering the axial passage in 4said sleeve-like member, said l stem portion being of such length relative to said sleeve-like member that said polygonal end will engage said projection to disengage said blade from said slot before said sleeve-like member has been screwed onto said stem to the limit of the thread thereon.

1,3. The method of clamping together the fractured faces of a bone of such character as to be capable of holding a threaded member therein, comprising making a small incision adjacent a readily accessible portion of the bone on one side of the fracture, aligning the fractured portions of the bone, inserting a pair of members through said portion of the bone across said fracture and into the portion of the bone on the other side of said fracture to hold said portions of the bone against relative rotation, drilling a hole from said incision into said bone across and a substantial distance beyond said fracture, -insetting a self-tapping anchoring member into said opening to screw-threadedly anchor said member in the'portion of the bone remote from said incision, said member being adapted to have screw-threaded engagement with a headed member, inserting a headed member into said opening and threading the same onto said anchoring member to draw said head down on the outer surface of said bone at said incision` and draw the fractured surfaces of the bone toward each other. i

14. The method f clamping together the fractured faces of a bone of such character as to be capable of holding a threaded member therein, comprising making a small incision adjacent a readily` accessible portion of the bone on one side of the fracture,aligning the fractured porthrough said portion of the bone across said fracture and into the portion of the bone on the other side of said fracture to hold said portions of the bone against relative rotation, drilling a hole from said incision into said bone across and a substantial distance beyond said fracture, inserting a selfftapping anchoring member into said opening to screw-threadedly anchor said member in the portion of the bone remote from said incision, said member being adapted to have screw-'threaded engagement with a headed member, inserting a headed member into said opening and threading the same onto said anchoring member to draw said head down on the outer surface of said bone at said incision and draw the fractured surfaces of the bone toward each other, impacting said bone at said incision around said head, and screwing said headed member further onto said anchoring member to draw up the slack after impaction of said bone.

ping holding portion adapted to engage the threaded portion of said elongated member.

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