US3002514A - Hip setting pin - Google Patents

Description

Oct. 3, 1961 w. M. DEYERLE 3,002,514

HIP SETTING PIN Filed Jan. 24, 1958 2 Sheets-Sheet 1 IN VENTOR Oct. 3, 1961 w. M. DEYERLE 3,002,514

HIP SETTING PIN Filed Jan. 24, 1958 2 SheetsSheet 2 1N VENTOR mam/110 6 116 5% M? W ATTORNEYS ,r 3,0h2,5l4 I E Patented Oct. 3, 1961 3,002,514 HIP SETTING PIN William Minor Deyerle, 2222 Monument Ave, Richmond, Va. Filed Jan. 24, 1e58, Ser. No. 711,016 Claims. (Cl. 128-92) The present invention relates to methods and attachments for fixation of fractures in the upper extremity of the femur, slipped epiphyses, and the like.

A number of techniques have been heretofore devised using special devices for securing fixation of the upper portions of the femur so as to prevent displacement of the head of the femur relative to the shaft. These are designed for fractures which occur in the head or neck of the femur or in the intertrochanteric region. For example, the Smith-Peterson nail having three longitudinal and radially projecting fins joined along the longitudinal axis of the nail and inclined at 120 to, each other has been devised to provide a measure of fixation of the fracture. The Smith-Peterson nail is designed to be driven into the neck and head of the femur from the outside of the femur shaft at an angle of approximately 135 with the axis of the femur shaft. Various modifications of the Smith-Peterson nail have also been devised all of which depend solely upon the center nail for fixation. The degree of fixation which is available with fixation nails of this type has never been adequate to allow partial or total weight bearing by the fracture patient until the bone healing was complete, as the torsion resistant and shear resistant forces embodied by the Smith-Peterson nail on the coacting bone surfaces was inadequate to prevent any slipping or rotation of the neck or head fracture.

In connection with intertrochanteric fractures, it has been proposed that a thin metal plate be secured to the shaft of the femur below the fracture area by hip screws, and three bone screws fitted in spaced apertures in the plate be threaded into the femur through the neck and into the head of the bone. The bone screws are designed to be directed along inwardly converging axes, and, when viewed in side elevation one of the screws crosses the other two screws in the area of the femur head. This arraugement was primarily designed only for fractures in the intertrochanteric region, and not in the neck region of the femur, and does not act in conjunction with a firm fixation nail such as the Smith-Peterson nail nor does it allow for massive fixation of the head of the femur relative to the shaft.

It has also been proposed to drive several fixation pins of very small diameter from the outside of the femur shaft through the neck and head of the femur and into the proximal cortex of the head. This, however, has not been proposed in conjunction with a fixation nail, the fixation pins are merely inserted through the fracture area individually without carefuly defined relation to each other and in no orderly method, and are not attached to anything that secures the fixation at the lateral cortex or outside of the shaft. Further, if any absorption or impaction of the fracture occurs, the points of such fixation pins may be driven through the proximal cortex and cartilage sheath on the head of the femur and produce grating and pain at the hip joint.

In each of the above systems of fixation, the fixation has been such that it has been necessary to avoid any weight bearing on the affected limb until the bone healing is complete, frequently involving periods of as long as six months.

The medical profession has long known that weight bearing causing contact compression at the fracture site, where the bones could be mechanicaly held so as to allow for the contact compression, was beneficial in stimulating bone growth. The prior art techniques described above,

however, involve primarily holding devices only, and weight bearing is discouraged for a period of approximately six months. Any inadvertent weight bearing in these types of holding devices could cause disaster.

An object of the present invention, therefore, is the provision of a novel method and means for fixation of bone fractures in weight bearing bones, wherein the disadvantages of the above described prior techniques are minimized or entirely eliminated.

Another object of the present invention is the provision of a novel method and means for fixation of fractures in the upper regions of the femur, specifically in the neck, head and intertrochanteric regions of the femur, for absolutely immobilizing the fracture against shearing and torsion forces while allowing for absorption at the fracture site and contact compression exerted by the weight and the muscles of the body.

Another object of the present invention is the provision of a novel method and means for fixation of fractures in the upper regions of the femur which immobilizes the fracture to encourage partial early weight bearing and ambulation of the patient, and thereby stimulate growth of new bone and reduce occurrence of nonunion or aseptic necrosis.

Another object of the present invention is the provision of a novel fixation device for fixation of fractures in the upper regions of the femur, which precisely maintains the fixation elements at the desired predetermined angle even under early partial weight bearing while allowing for relative displacement of the proximal and distal sides of the fracture.

Other objects, advantages and capabilities of the pres ent invention will become apparent from the following detail description, taken in conjunction with the accompanying drawings illustrating several preferred forms of the invention.

In the drawings,

FIGURE 1 is a fragmentary diagrammatic view of the upper portions of a femur having a fracture in the neck thereof, illustrating the manner of guiding a drill through the lateral cortex in properly oriented relation to the axis of the femur shaft, in accordance with the present invention;

FIGURE 2 is a similar diagrammatic view of the fractured femur, illustrating the manner of insertion of the fixation nail in cooperation with the nail plate, the nail plate being shown in vertical section;

FIGURE 3 is a diagrammatic view illustrating the fixation nail, pins and nail plate in final position on the fractured femur, parts being shown in vertical section and parts in elevation, and the nail plate and pin assembly being slightly modified relative to the form shown in FIGURE 2;

FIGURE 4 is a transverse section view taken along the line 4-4 of FlGURE 3;

FIGURE 5 is a perspective view of a modified form of a fixation nail and plate which may be used in practicing the method of the present invention;

FIGURE 6 is a diagrammatic view of a fractured femur with another form of fixation, apparatus disposed in final positon on the femur;

FIGURE 7 is a diagrammatic view illustrating the manner of guiding the fixation nail and fixation pins of the form show in FIGURE 6 into the femur in proper alignment with the femur shaft and with each other;

FIGURE 8 is a transverse section View taken along the line 8-8 of FIGURE 7; and

FIGURE 9 is a fragmentary section view taken along the line 9-9 of FIGURE 8.

The present invention is concerned primarily with the fixation of fractures in .the upper regions of the femur.

Referring to the fragmentary illustrations of the femur in FIGURES l, 2, 3, 6 and 7 of the drawings, the principal structural features of this portion of the femur are the shaft 10, the trochanter ill, the constricted neck 12, which extends along an axis usually inclined at about 135 to the axis of the shaft 16, and a head 13 which forms one element of the hip joint. For purposes of illustration of the specific application of the present in vention, it will be assumed that the femur fracture, indicated by the reference character 14, occurs across the constricted neck 12.

Referring specifically to FIGURES 3 and 4 of the drawings, the fixation assembly, indicated generally by the reference character 15, which is preferably formed of stainless steel or other metal of suitable strength adaptable to be placed under the flesh without adverse effects, includes a nail plate 16 which is a vertically elongated body having an enlarged upper or head portion 17, preferably of about one-half inch thickness, and a thin lower or leg portion 18. The nail plate 16, when considered in transverse section, is slightly concave along the proximal surface 19 thereof facing the femur to conform substantially to the curvature of the femur shaft 10, and the proximal surface 19 of the nail plate 16 when considered in side elevation is substantially straight conforming more or less to the profile of the outer side or lateral cortex of the femur shaft 10. The leg portion 18 of the nail plate 16 is provided with a plurality of vertically spaced holes 20 through which hip screws 21 may be projected and threaded into the shaft 10 of the femur to securely anchor the nail plate 16 to the femur shaft.

Extending inwardly from the proximal surface 19 of the nail plate 16 into the head portion 17 and along an axis inclined at about 135 to the vertical axis of the nail plate 16 is a cylindrical socket 22 terminating within the head portion 17 in an annular shoulder 23 lying perpendicular to the axis of the socket 22 for-reception of a fixation nail 24 of the Smith-Peterson type or the like. The base of the fixation nail 24 is designed to butt against the annular shoulder 23 and the adjacent surfaces of the nail 2.4 register with the cylindrical surface of the socket 22 so as to incline the .nail 24 at the angle of approximately 135 to the vertical axis of the nail plate 16. An obvious alternative would be to form the fixation nail 24 integrally with the nail plate 16 locating the nail 24 in the same angular relation to the nail plate 16 as is shown in FIGURE 3. An opening 25 extends toward the distal surface 26 of the nail plate 16 and communicates with an enlarged bore 27 opening through the distal surface 26 of the nail plate 16. The opening 25 is designed to receive the threaded shaft of an anchoring bolt 28 to permit the threaded shdt to extend into the threaded socket "in the base of the Smith-Peterson type fixation nail 24 for anchoring the base of the fixation nail 24 against the annular shoulder 23, the bore 27 being .of sufiicient diameter to accommodate the head of the anchoring bolt 28.

A plurality of holes 29, usually 8, extend through the head portion 17 of the nail plate 16 in radially spaced relation to the axis of the socket 22, the holes 23 being preferably disposed in a square pattern centered on the axis of the socket 22. The holes 29 form guide holes arranged along parallel axes inclined at approximately 135 to the vertical axis of the nail plate 16 and are of a size to just accommodate conventional fixation pins 30, which are usually of about Ms inch or inch diameter, to hold the pins 30 on parallel axes. The fixation pins 30 are preferably of the type having threaded shanks adapted to receive tapered tapes 31 thereon.

The form of assembly illustrated in FIGURE 2 is substantially identical to that illustrated in FIGURE 3, except that the cylindrical socket 22' opening through the proximal surface 19 of the nail plate 16 for receiving the base of the fixation nail 24 extends continuously through the entire thickness of thenail plate 16 to permit rela'e tive axial movement of the nail 24, the unaltered elements of the modified assembly 15' illustrated in FIG- URE 2 being designated by the same reference characters applied in connection with FIGURE 3.

A modified form of assembly, designated by the reference character 32;, is illustrated in FEGURE 5. In the modified form of assembly, the fixation nail and nail late are an integral unit, the nail, indicated by the reference character 3.3, having a cylindrical base portion 34 and three axially elongated fins 35 inclined at to each other and radiating from the axis of the fixation nail 33. integrally joined to the base of the nail 33 is a nail plate portion 36 having a thickened head 37 shaped like the head portion 17 in FIGURE 3 and a depending leg 38. The head 37 is centrally apertured and tapped, as indicated at 39, for connection with a driver and is provided with a group of guide holes 40 of a size to slidably receive conventional fixation pins 30. The depending leg 38 of the nail plate portion 36 is provided with vertically spaced openings 41 for hip screws 21 for anchoring the leg 38 to the shaft 10 of the femur. The axes of the nail 33 and the holes 40 are inclined at approximately to the plane .of the head 37 and the head 37 arranged in axial alignment with the leg 33, the axial extent of the holes 40 due to the thickened nature of the head 37 accurately holds the fixation pins in the desired pattern and axial alignment.

Still another form is disclosed in FIGURE 6, wherein the fixation nail is removably secured to the nail plate. In this form, the nail plate, indicated by the reference character 42, includes a disk like head 43 and a depending leg 44, the head 43 being centrally apertured to receive an anchoring bolt 45 for securing the base of the Smith-Peterson type nail 24 to the head 43 and having holes 46 in the same pattern as is shown in FIGURE 5 for receiving a plurality, for example eight, conventional fixation pins 30. The leg 44 is provided with spaced apertures 46 for receiving bone screws or nails 47 for anchoring the same to the shaft 10 of the femur.

A director or jig, indicated by the reference character 5% and illustrated in FIGURES l, 7, 8 and 9, is provided to effect orderly insertion and precise location and parallelism of the fixation pins 30. The director 50 comprises a cylindrical body 51 having an inner face 52 inclined at approximately 135 .to the axis of the cylindrical body 51 and an outer face 53 disposed normal to the axis of the cylindrical body 51. The body 51 has a central guide bore 54 of slightly over one-half inch in diameter for slidably accommodating a Smith-Peterson type fixation nail 24, and a plurality of holes 55 of just over one-eighth inch in diameter and spaced radially from the axis of the guide bore 54 in parallelism with the axis thereof to form guide openings for the fixation pins 30.

The length of the director 50 along the axis thereof is sufiicient to provide fixation pin guiding holes 55 of sufficient length to insure that the fixation pins 30 will be driven in substantial precise parallelism with each other.

As illustrated in FIGURE 9, the director 50 may also be provided with a removable obturator sleeve 56 having an inclined inner end 57 corresponding to the inclination of the inner face 52 of the director 50. The obturator sleeve 56 has an outer diameter corresponding substantially to the diameter of the central guide bore 54 of the director 5%} to provide a sliding fit therewith, and an inner diameter corresponding substantially to the diameter of a standard threaded driver shank, or an inner diameter of about %2 of an inch. In the latter case, a headless threaded screw or shaft, indicated generally at 58, which slidably fits into the obturator sleeve 56 would be employed to be threaded into the threaded socket at the base of the Smith-Peterson type nail 24. The other ing to maintain the screw or shaft 58 centered in the guide bore 54 of the director 50 to maintain proper control over the axis along which the fixation nail is driven.

In applying the fixation assembly of the present invention to a fractured femur, a one-half inch drill is first drilled into the hard cortical bone at a point between one and one-half inches below the greater trochanter. Such a drill is schematically illustrated in FIGURE 1 and identified by the reference character 60. The drill hole is designed to pierce only the hard cortical bone to allow the sharpened lead edge of the Smith-Peterson type fixation nail 24 to be introduced into the softer inner portions of the femur. The axis of the drill hole may be conveniently set to the approximately 135 angle of the axis of the constricted neck 12 by employing the director or the nail plate 16' as a guide. In such instances, the proximal surface or face of the director or nail plate will be disposed against the outer side of the femur shaft at the proper point below the greater trochanter whereupon the axis of the guide bore 54 or socket 22' will be approx mately properly oriented at the desired angle. The separate Smith-Peterson type fixation nail 24, or the fixation nail, for example 33, integrally associated with a nail plate, is then inserted manually into the drill hole and inserted in a fish-tail fashion almost to but not through the fracture site 14. Since the interior of the bone is relatively soft and sponge like, it is possible to manually drive the fixation nail 24 beyond the point of maximum penetration of the drill to the desired point of penetration, by means of a driver of the type illustrated in FIGURE 2 and noted by the reference character 61. By inserting the fixation nail in this manner, the hard cortical bone tends to maintain the fixation nail within the confines of the bone and guide the same to the proper axis of the penetration.

If the fixation nail is not integral with the nail plate, the nail plate of the type shown at 16 or 16 in FIGURES 3 and 2 should then be assembled onto thenail 24 or the director 50 should be slipped over the base portion of the nail 24. In the assembly of the nail plate 16 to the nail 24, it is merely necessary to seat the base of the fixation nail 24 in the cylindrical socket 22 against the annular shoulder 23 thereof, and thread the anchoring bolt 23 through the bore 27 and into the threaded socket in the base of the fixation nail 24.

An X-ray is made at this point to determine Whether the positioning of the fixation nail is proper. If the position is satisfactory, at least one and preferably two fixation pins 30 should be inserted with a drill or other driving implement through the guide holes 29 in the nail plates 16, 16, or the guide holes 55 in the director 5G, and through the constricted neck 12, the fracture site 14 and into the hard cortical bone of the head 13. If desired, these first fixation pins may be driven on through the surface of the head 13 and into the solid pelvic bone. The purpose of driving these first one or two fixation pins 30 before projection of the fixation nail 24 through the fracture site and into the head 13 is to transfix the head temporarily and prevent separation of the proximal side of the fracture from the distal side when the fixation nail 24 is driven on through the fracture site.

In case the fixation apparatus of the type shown in FIGURES 2 and 3 are being used, in which case the nail plate 16 is either bolted to the fixation nail 24 or the plate 16' is slipped onto the base portion of the nail, the nail is then driven on through the fracture site and into the femur head 13 to within one-half to three-quarter of an inch of the proximal cortex of the femur head. The remainder of the fixation pins 3% may then be inserted through the unoccupied holes Zfi of the nail plates 16 or 16' to complete the massive fixation of the fracture. Each of the fixation pins 30 is driven as near to the surface of the femur head 13 as possible, the leg being wobbled after each fixation pin is inserted fully to be sure that no grating is produced at the joint. The taps 31 are then threaded onto the fixation pins 30 until they abut the distal surface of the nail plate 16 or 16', the taps being provided to prevent proximal migration of the pins into the hip joint, and the projecting portions of the fixation pins 30 extending outwardly from the taps 31 are sheared ofi.

In the case of the nail and plate unit 32 of the type shown in FIGURE 5 wherein the enlarged head 37 is coplanar with the depending leg 38, the guide holes 40 are of sufficient length to effect precise alignment of the fixation pins 39 with the fixation nail 24-. If a shallower plate were used providing holes of insufficient length to insure precise pin alignment the director 50 may be butted against the plate with the bore Ed in alignment with the tapped opening 39 to guide the pins.

In the case of the fixation assembly illustrated in FIGURES 6 and 7, the director 50 is telescopically supported over the projecting base portion of the nail 24 in the manner illustrated in FIGURES 7 and 9 so as to proxide a precise guide for aligning the first one or two fixation pins 30 to be inserted through the neck 12 and into the head 13. The fixation nail 24- may then be driven on through the fracture site and into the head 13 either with the director 5% still fitted on the base portion of the nail 24 or with the director 50 removed. In any event, the director may be properly registered in axial alignment with the fixation nail 24 when the nail is driven to its final position within the femur illustrated in FIGURE 6, by means of the threaded screw or shaft 53 threaded into the base socket of the fixation nail 24 and the obturator sleeve 56, which serves as an exposed extension of the fixation nail to maintain proper alignment of the director 56 therewith. Following insertion of the remaining fixation pins 30, the separable nail plate 42 may then be fitted onto the fixation pins 30 and bolted onto the projecting end of the nail 24. The taps 31 may then be threaded onto the fixation pins 30 and the leg of the nail plate 42 anchored to the shaft 10 of the femur.

The method and fixation assembly described above provides a massive fixation of the fracture site by the combination of the fixation nail and the centered group of accurately placed, parallel fixation pins 30, all of which are rigidly fixed and maintained in the cortex by the nail plate anchored to the shaft of the femur to maintain the rigidity at the shaft site as well as in the head. This provides sufiicient immobilization to permit rapid weight hearing by the patient. In each of the forms herein shown, wherein the fixation nail 24 is either bolted to or integral with the nail plate, or is axially slidable within the socket 22' in the case of the nail plate 16, the absolute immobilization is adequate to resist shearing or torsional forces which would adversely affect the reduction of the fracture so as to permit early weight bearing, but allowance is made by absorption and continued contact compression to stimulate bone growth. in the case of the forms shown in FIGURES 3, 5 and 6 wherein the fixation nail 24 is immovable relative to the nail plate, the one-half to three-quarters inch clearance between the proximal end of the fixation nail 2d and the surface of the head of the femur is sufficient to accommodate absorption and yet maintain the proper angle with the cortex and not allow for any loosening in the distal cortex. In the case of the form shown in FIGURE 2, sliding fixation is permitted by the sliding coupling of he fixation nail 24 in the socket 22' of he nail plate 16 to accommodate absorption at the fracture site.

In summary, the apparatus of the present invention affords a means of fixation of fractures of the femur which securely fixes up to eight fixation pins in the proximal cortex of the head of the femur and securely maintains them in the cortex by a nail plate and fixation nail in one or two piece combinations which attaches to the shaft of the femur. This maintains the proper angle with the cortex, avoids any loosening in the distal cortex, and gives absolute immobilization against shearing as well as torsion forces while still allowing for absorption at the fracture site and continued contact compression asserted by the weight and muscles of the body, decreasing the possibility of nonunion and aseptic necrosis and permitting early ambulation of the patient.

The director 50 is also of particular advantage in connection with bone grafts. in the case of slipped epiphysis, where it is desirable to accurately fix the slipped epiphysis at the epiphyseal site rather than reducing the slipped epiphysis, the director or a nail plate of the type illustrated in FIGURE 2 may be of definite ad vantage as a guide for the drill 69 which is required to drill a large hole through the neck 12 of the femur and across the epiphyseal line to permit placement of a large cancellous bone graft across this line. Some fixation may be achieved by inserting four to eight fixation pins 3t) into the femur and penetratim the slipped epiphysis, as guided and precisely positioned by the holes 55 or 29 of the director 50 or nail plate 16', respectively. Then, the nail plate 16' or a nail plate of the type indicated at 42 in FIGURE 6 may be employed to fix the distal ends of the fixation pins 30.

While several embodiments of the present invention have been particularly shown and described, it is apparent that various modifications may be made therein without departing from the spirit and scope thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and are'set forth in the appended claims.

What is claimed is:

1.. An instrument for use in the fixation of fractures in the upper region of the femur comprising an elongated fixation nail adapted to project through the distal surface of the femur and the neck of the femur approximately along the axis of the neck and into the head thereof to a selected distance from the proximal surface of the femur head spacing the end of the nail therefrom sulficiently to accommodate absorption at the fracture site, said nail having a base to project outwardly from the distal surface of the femur, a vertically elongated nail plate having a head portion at the upper end thereof adjacent said base of said nail and a depending leg portion to be fixedly mounted on the distal surface of the femur shaft immediately below the trochanter, said nail being held by said nail plate against displacement from a pre selected angular relation to the vertical axis of said nail plate to maintain a selected angle between the nail and the femur shaft, said head portion having a plurality of holes extending along axes parallel to and spaced symmetrically radially of the nail axis, and a plurality of fixation pins slidably extending through said holes to project inwardly of said nail plate through the neck of the femur and terminate in the proximal cortex of the femur head, said fixation pins being slidably held by the bounding surfaces of said holes to resist angular displacement of the fixation pins in the distal cortex from axes paralleling said nail axis, whereby said nail, nail plate and fixation pins coact to provide massive fixation of the fracture immobilizing the fracture against shearing and torsion forces while accommodating absorption at the fracture site and contact compression thereon.

H 2. An instrument for use in the fixation of fractures in the neck of the femur and adjoining regions comprising an elongated fixation nail of the type having a plurality of longitudinal and radial fins adapted to be projected through the distal lat ral cortex of the femur and the neck of the femur approximately along the axis of the neck to space the inner end of the nail a selected dis tance from the proximal surface of the femur head, said nail having a cylindrical base portion to project outward- Iyfrom the distal lateral cortex of the femur, a vertically elon ated nail plate having a thickened head portion at the upper end thereof adjacent said base of said fixation nail and a depending leg portion to be fixedly anchored to the distal lateral cortex of the femur shaft immediately below the trochanter and intimately abutting the lateral cortex over a substantial vertical extent, said nail being held by said nail plate against angular displacement from a preselected angular relation to the vertical axis said nail plate to maintain a selected angle between the nail and the femur shaft, said thickened head portion having a plurality of guide holes extending therethrough and lying in a regular geometric path centered on said nail axis, and a plurality of fixation pins slidably supported for axial movement in said holes to project inwardly of said nail plate through the neck of the femur and terminate in the proximal cortex of the femur head, the axial length of said guide holes being several times the diameter of said fixation pins said fixation pins being held by the bounding surfaces of said holes on parallel axes paralleling the fixation nail by the bounding walls of said guide holes to resist angular displacement of the fix Ion pins in the distal lateral cortex and being free to slide axially within said holes to accommodate absorp tion at the fracture site and contact compression thereon.

3. An instrument for use in the fixation of fractures in the neck of the femur and adjacent regions comprising an elongated fixation nail adapted to project through the distal lateral cortex of the femur and the neck of the femur approximately along the axis thereof and into the head of the femur, said fixation nail having a plurality of longitudinal and radial fins to be disposed within the femur and. a cylindrical base portion to project outwardly from the distal lateral cortex of the femur having a threaded central opening therein opening through the base wall of the nail, a vertically elongated nail plate hav' ing a thickened head portion at the upper end thereof and a depending leg portion to be anchored to the distal latteral cortex of the femur shaft immediately below the trochanter, said head portion of said plate having a bore extending entirely therethrough along an axis inclined at a selected angle to the vertical axis of the nail plate corresponding substantially to the angular relation between the axes of the femur neck and shaft and complementing the cross-section of the base of said nail slidably receiving the base of said nail therein with the surface of said bore holding the same at said selected angle, said head portion having a plurality of diametrically spaced pairs of guide holes extending therethrough along axes parallel to and spaced symmetrically relatively to the axis of said bore, a plurality of fixation pins slidably supported in said guide holes to project inwardly of said nail plate, through the neck of the femur and terminate in the proximal cortex of the femur head, the axial length of said guide holes being several times the diameter of said fixation pins said fixation pins being held by the bounding walls of said guide holes to resist angular displace-' ment of the fixation pins in the distal lateral cortex and being slidably supported for axial displacement, whereby said nail, nail plate and fixation pins coact to provide massive fixation of the fracture immobilizing the fracture against shearing and torsion forces while the nail plate accommodates relative axial displacement of said nail and fixation pins in response to absorption at the fracture site and contact compression thereon.

4. An instrument for use in the fixation of fractures in the neck of the femur and adjacent regions comprising an elongated fixation nail adapted to project through the distal lateral cortex of the femur and the neck of the femur approximately along the axis thereof and into the head of the femur, said fixation nail having a plurality of longitudinal and radial fins to be disposed within the femur and a cylindrical base portion to project outwardly from the distal lateral cortex of the femur having a threaded central opening therein opening through the base wall of the nail, a vertically elongated nail plate 9 having a thickened head portion at the upper end thereof and a depending leg portion to be anchored to the distal lateral cortex of the femur shaft immediately below the trochanter, said head portion of said plate having a socket forming a seat for the base of said nail extending through the face thereof adjacent the femur along an axis inclined at a selected angle to the vertical axis of the nail plate and a bore opening through the opposite face of the plate in axial alignment with said socket and an annular constriction between said bore and said socket having an opening communicating said bore with said socket, a threaded bolt extending through said bore and said last-mentioned opening and into said threaded opening in said nail fixing said nail to said plate, said head portion having a plurality of diametrically spaced pairs of guide holes extending therethrough along axes parallel to and spaced symmetrically relative to the axis of said bore, a plurality of fixation pins slidably supported in said guide holes to project inwardly of said nail plate through the neck of the femur and terminate in the proximal cortex of the femur head, said fixation pins being held by the bounding walls of said guide holes to resist angular displacement of the fixation pins in the distal lateral cortex and being slidably supported for axial displacement, whereby said nail, nail plate and fixation pins coact to provide massive fixation of the fracture immobilizing the fracture against shearing and torsion forces while the nail plate accommodates relative axial displacement of said nail and fixation pins in response to absorption at the fracture site and contact compression thereon.

'5. An instrument for use in the fixation of fractures in the neck of the femur and adjacent regions comprising an elongated fixation nail adapted to project through the distal lateral cortex of the femur and the neck of the femur approximately along the axis thereof and into the head of the femur, said fixation nail having a plurality of longitudinal and radial fins to be disposed within the femur and a cylindrical base portion to project outwardly from the lateral distal cortex of the femur, a vertically elongated nail plate having a thickened head portion at the upper end thereof integrally joined to the base of said nail and a depending leg portion to be anchored to the distal lateral cortex of the femur shaft immediately below the trochanter, the axis of said nail being inclined to the vertical axis of said nail plate at a selected angle corresponding substantially to the angular relation between the axes of the femur neck and shaft, said head portion having a plurality of guide holes extending therethrough and lying in a regular geometric path centered on said nail axis, said guide holes extending along axes parallel to and spaced in symmetrically arranged pairs relative to the axis of said nail, and a plurality of fixation pins slidably supported in each of said guide holes to project inwardly of said nail plate through the neck of the femur and terminate in the proximal cortex of the femur head, said fixation pins being held by the bounding walls of said guide holes to resist angular displacement of the fixation pins in the distal lateral cortex and being free to slide axially within said holes to accommodate absorption at the fracture site and contact compression thereon.

6. The combination recited in claim 2, wherein there are eight of said guide holes and said eight guide holes are arranged in a square pattern centered upon the axis of said nail, and one of said fixation pins is located in each of said guide holes.

7. The combination recited in claim 3, wherein there are eight of said guide holes and said eight guide holes are arranged in a square pattern centered upon the axis of said nail, and one of said fixation pins is located in each of said guide holes.

8. The combination recited in claim 4, wherein there are eight of said guide holes and said eight guide holes are arranged in a square pattern centered upon the axis aooasis 10 of said nail, and one of said fixation pins 'is located in each of said guide holes.

9. An instrument for use in the fixation of fractures in the neck of the femur and adjacent regions comprising an elongated fixation nail adapted to project through the distal lateral cortex of the femur and the neck of the femur approximately along the axis thereof and into the head of the femur, said fixation nail having a plurality of longitudinal and radial fins to be disposed within the femur and a cylindrical base portion to project outwardly from the lateral distal cortex of the femur, a vertically elongated nail plate having a thickened head portion at the upper end thereof integrally joined to the base of said nail and a depending leg portion to be anchored to the distal lateral cortex of the femur shaft immediately below the trochanter, the axis of said nail being inclined to the vertical axis of said nail plate at a selected angle corresponding substantially to the angular relation between the axes of the femur neck and shaft, said head portion having eight guide holes extending therethrough and arranged in a square pattern centered on said nail axis, said guide holes extending along axes parallel to and spaced in symmetrically arranged pairs relative to the axis of said nail, and a fixation pin slidably supported in each of said guide holes to project inwardly of said nail plate through the neck of the femur and terminate in the proximal cortex of the femur head, said fixation pins being held against angular displacement in the distal lateral cortex by the bounding walls of said guide holes and being free to slide axially within said holes to accommodate absorption at the fracture site and contact compression thereon.

10. An instrument for use in the fixation of fractures in the neck of the femur and adjacent regions comprising a vertically elongated anchoring plate having a thickened head portion at the upper end thereof of substantially rectangular configuration and a depending leg portion to be fixedly mounted on the distal lateral cortex of the femur shaft immediately below the trochanter, said head and leg portions having a continuous concave cylindrical surface portion adapted to substantially conform to and abut the lateral cortex over a substantial vertical extent, said head portion having a substantially centrally located bore extending entirely therethrough along an axis inclined at a selected angle to the vertical axis of the anchoring plate corresponding substantially to the angular relation between the axes of the femur neck and shaft and eight guide holes arranged in a square pattern substantially centered on said head portion, said guide holes extending along axes parallel to and spaced in symmetrically arranged pairs relative to the center of said head portion, a plurality of fixation pins slidably supported in at least the majority of said guide holes to projeot inwardly of said anchoring plate through the neck of the femur and terminate in the proximal cortex of the femur head, the square pattern of guide holes including two transversely spaced rows of guide holes spaced apart a distance corresponding substantially to the radius of a femur neck, said head portion being of sufiicient thickness so that the axial length of said guide holes is several times the diameter of one of said fixation pins, and said fixation pins being held by the bounding walls of said guide holes to resist angular displacement of said fixation pins in the distal lateral cortex and being slidably supported for axial displacement to accommodate absorption at the fracture site and contact compression thereon whereby the anchoring plate and fixation pins coaot to provide massive fixation of the fracture immobilizing the fracture against shearing and torsion forces while the anchoring plate accommodates relative axial displacement of the fixation pins in response to absorption and contact compression.

(References on following page) V 11 Refsxenus Cited in. the file of this patent UNITED STATES PATENTS Friddle Ian.23,1940

Longfellow Jan. 28, 1947 5 McKibbon Mar. 14, 1950 Lorenzo Oct. 24, 1950 95-658 '12, Longfellow -b Jan. 9, 1951 Bambara et a1. Nov. 29, 19.55 Pohl Dec. 4, 1956 FOREIGN PATENTS I Sweden May 9, 1939

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