WO2007023101A1

WO2007023101A1 - Proximal femur nail

Info

Publication number: WO2007023101A1
Application number: PCT/EP2006/065218
Authority: WO
Inventors: Frank Orschler; Olaf Meyer; Arnd Ehrhardt; Ulrich Finger; Matthias Bock; Erich Orschler
Original assignee: Königsee Implantate und Instrumente zur Osteosynthese GmbH
Priority date: 2005-08-23
Filing date: 2006-08-10
Publication date: 2007-03-01
Also published as: DE102005039854A1; DE102005039854B4; DE102006032814A1

Abstract

The invention relates to a proximal femur nail (1) comprising a femur neck supporting element fixed in a bore. The inventive supporting element is embodied in the form of support screw (5). Said support screw comprises a through slot (9) extending along a longitudinal section and to the support screw end opposite to a self-cutting screw and into the threaded bore (13) which extends in the longitudinal axis direction and is used for receiving a compression screw provided with an external thread complementary to the threaded bore. Said bore is used for receiving a locking pin (8) in a longitudinal direction of the nail head until the reception area of the support screw is guided. Said locking pin, in the inserted state thereof, penetrates into the through slot and ensures the anti-rotational locking of the support screw which abuts, by the action of the compression screw, against the part thereof which is located in the through slot in such a way that it makes it possible to produce a relative movement between the neck of the femur supporting screw and the femur nail.

Description

Proximal femoral nail

description

The invention relates to a proximal femoral nail with a femoral neck member received in a bore, according to the preamble of claim 1.

Proximal femoral nails are known in the art for stabilizing pertrochanteric, intertrochanteric or high subtrochanteric fractures. Known femoral nails have a larger diameter proximal end and a distal nail end which may have some flexibility to minimize stress concentrations. It is also previously known that the femur nail expediently has an angle adapted to the anatomy of, for example, 6 ° over the longitudinal axis.

The head of a known femoral nail is closed by a screw, which at the same time is able to secure a nail-cutting self-tapping hip screw against rotation or displacement. A correspondingly large internal bore receives the femoral neck screw necessary for stabilizing the fracture, which is normally designed to be self-tapping. The hip slide screw represents a rotation safety relative to the femoral neck screw. Usually, the femoral neck screws still have a slip-through protection.

At the distal end of the nail holes are introduced, which serve to receive at least one locking bolt. The femoral nail explained briefly above is surgically inserted as deeply as possible into the femur opening, with subsequent introduction of the hip slide screw and the femoral neck screw with the aid of drilling templates. This insertion is accomplished by the use of guidewires, with direction and position controlled via appropriate image rendering technique during the execution of this operative step. After a determination of the lengths of the hip and femoral neck screw, they are screwed in using a special key. In the case, that compression of the fracture is required, it is possible in known solutions to provide a compression nut on the target bow attachment. With the help of this compression nut then the fracture can be compressed via the femoral neck screw. After removal of the aiming arm attachment, however, a compression is no longer possible with these known nails. The prior art explained is based on the PFN fenemail offered and sold by Synthes.

The TARGON PF femur nail, manufactured and sold by the company Aeskulap, consists of the intramedullary nail, a self-tapping screw and a support sleeve into which the support screw can telescope. In addition, another screw is provided which blocks unwanted rotation of the femoral neck screw. The femoral neck screw can slide in this variant of the prior art in intramedullary nail in its longitudinal direction, which should allow sintering of the fracture.

However, with this femoral nail design, it is not possible without additional application of special target devices to effect a defined compression of the fracture.

From the above, it is therefore an object of the invention to provide a further developed proximal femoral nail with a femoral neck member received in a bore, this femoral nail on the one hand to have the possibility of an integral compression of the fracture and on the other hand has the ability to easily cause a rotation assurance, and without having to provide a separate Hüftgleitschraube with additional bore in the bone.

The object of the invention is achieved with a proximal femur nail according to the feature combination according to claim 1, wherein the dependent claims represent at least expedient refinements and developments.

According to the invention, the proximal femoral nail and the femoral neck support element are characterized in that the femoral neck support element is min. Having at least partially extending in the longitudinal direction, extending into the bore and / or in the bore projecting into shape and / or fastening elements suitable form for forming a rotational security for the femoral neck support element.

This basic idea according to the invention can be realized by various embodiments. In a first embodiment, the femoral neck support element has an edged profile shape, in particular a cross profile, and the bore has an angular bore profile, in particular a cross slot profile, for a sliding, rotationally secured insertion of the femoral neck support element. This embodiment can be implemented without additional fastening means and makes use of a simple positive connection between the support element and the bore in the proximal femoral nail.

The femoral neck support member is preferably formed in this embodiment as a femoral neck nail. This is driven along the profile form closure through the hole of the proximal femoral nail sliding into the bone tissue.

In another embodiment, the femoral neck support member is a self-tapping femoral neck support screw received into the bore and the femur nail has a locking pin insertable at the proximal end in the nail head longitudinal direction and at least one locking bore provided at the distal end. In this case, the support screw has a passage section extending over a longitudinal section. At the opposite end of the self-tapping screw of the support screw this has a longitudinal axis extending threaded bore for receiving a compression screw with a threaded bore complementary external thread.

The bore for receiving the locking pin is guided in Nagelkopflängsrichtung to over the area for receiving the support screw, wherein the locking pin penetrates the through slot in the inserted state and thereby causes a rotational securing of the support screw. When the compression screw is actuated, it comes into abutment with the part of the securing pin located in the passage slot, so that a relative movement between the femoral neck support screw and the femoral nail can be achieved in the sense of compression.

The inventive femoral nail has in an advantageous embodiment of the invention, a continuous cannulation.

Likewise cannulated throughout is the support screw.

At the end of the support screw which serves to receive the compression screw, the support screw has a bevel.

The locking pin is designed as a pin with conical tip and stepped diameters, wherein in the region of the external thread a blind hole with internal polygon for receiving a tool, e.g. a Allen key is formed.

Preferably, the compression screw is designed as a grub screw. By a provided at the distal end slot as a locking hole dynamic locking is given, i. the femoral nail can still glide distally over a given area before seating on the distal locking screw.

In terms of application, the femoral nail is inserted proximally into the medullary cavity of the femur. Thereafter, the support screw is screwed through the nail in the femoral head and aligned so that the inclination of the screw is parallel to the axis of the nail head. For this purpose, a special Eindrehinstrument is used.

Subsequently, the locking pin is screwed in the longitudinal direction of the nail through the slot of the support screw in the nail. With the introduction of the locking pin on the one hand, the support screw is secured against rotation. On the other hand, the sliding path of the support screw in the nail is limited to the length of the passage slot. An emigration from the nail is excluded. The support screw remains dynamic, ie movable, whereby the perforation of the femoral head during sintering of the fracture zone is effectively prevented.

A desired intraoperative compression of the fracture gap can be done with the aid of the compression screw, which is supported on the locking pin. The desired compression pressure is maintained according to the position of the compression screw.

In one embodiment of the invention, the support screw in the region of its inclination has a groove of predetermined depth, in which the Eindrehinstrument is inserted and guided in the manner of a screwdriver.

The invention will be explained below with reference to an embodiment and with the aid of figures.

Hereby show:

Fig. 1 different views of the proximal femoral nail;

Fig. 2 side view and sectional view of the self-tapping leg ha Istragschraube;

Fig. 3 is a view of the locking pin;

Fig. 4 is an illustration of the compression screw;

5 shows a representation of the femoral nail with already introduced bearing screw.

Fig. 6 is an illustration of the proximal Femurnagels with support screw and imminent introduction of the locking pin and Fig. 7 is an illustration of the proximal femoral nail with support screw, introduced locking pin and impending screwing the compression screw in the associated internal threaded portion of the support screw.

8 is an illustration of a femoral neck nail with a cross profile in a side view and in cross section,

9 is an adapted to receive the femoral neck nail of FIG. 8 embodiment of the proximal femur nail with profile bore,

10 is an illustration of the Femurnagels of FIG. 9 with an introduced support nail of FIG .. 8

The proximal femur nail 1 according to the figurative representations has an angling or curvature 2 corresponding to the anatomical conditions of the femur.

In the lower region of the femoral nail 1, a bore for the distal locking, introduced in the embodiment in the form of a slot 3.

In the nail head area is another hole 4, which serves to receive a femoral neck support screw 5.

The angular course of the bore 4 to the longitudinal axis of the nail 1 is also selected according to the anatomical conditions.

The femur nail according to the illustration of FIG. 1 has a continuous cannulation. 6 At the proximal end of the femoral nail 1, a bore 7 is introduced with internal thread. This bore 7 with internal thread serves to receive a securing pin 8 (see FIG. 3).

As can be seen in particular from FIGS. 1, 6 and 7, the bore 7 for receiving the securing pin 8 is guided in the longitudinal direction of the nail head over the region of the receptacle of the carrying screw 5, wherein the securing pin 8 in the inserted state penetrates the through-slot 9 within the carrying screw.

Above the bore 7 with internal thread is a blind hole 10, also located with an internal thread, which serves to receive a screw plug, not shown.

The internal thread of the bore 7 need not extend over the entire bore length, but only over a partial area, in particular preferably towards the proximal end.

The support screw according to FIG. 2 has the aforementioned passage slot 9, a continuous cannulation 11 and an end with self-tapping thread 12.

At the opposite end of the self-tapping screw 12 of the support screw 5 a running in the longitudinal direction of the threaded bore 13 is introduced, which serves to receive a compression screw 14 (see FIG. 4).

The self-tapping thread 12 opposite end of the support screw 5 has a slope 15.

In the region of the slope 15, a groove 16 is introduced, which serves to receive a special screwing tool (not shown). The locking pin 8 according to FIG. 3 has a substantially pin shape with a conical tip 17.

Over the length of the locking pin 8 may have a stepped diameter.

In the area of the external thread 18 of the securing pin 8, a blind bore with internal polygon 19 is introduced, specifically for receiving a tool, in particular in the form of a hexagon socket wrench.

The compression screw 14 according to FIG. 4 preferably has a maggot screw shape and likewise has a blind bore with internal polygon 20 for receiving a screwing-in tool.

FIG. 5 shows how the femoral neck support screw 5 was introduced into the bore 4 of the femoral nail 1. After the femoral neck support screw 5 has been screwed into the femur head, not shown, and aligned so that the bevelled end 15 extends substantially parallel to the proximal cylindrical nail, the insertion of the securing pin 8 via the associated hole 7 in the nail first

With the introduction of the locking pin 8, the femoral neck support screw 5 is secured against rotation on the one hand. On the other hand, the sliding path of the support screw 5 is limited to the length of the passage slot 9. An emigration from the nail is excluded.

The support screw 5 remains movable, whereby the perforation of the femoral head during sintering of the fracture zone and the associated shortening of the bone during healing can be prevented.

After the locking pin 8 has been introduced into the bore of the nail 1 as shown in FIG. 7, the compression screw 14 is inserted into the threaded hole 13. The desired intraoperative compression of the fracture gap is with the help of the compression screw 14, which is supported on the locking pin 8 secured.

In summary, the locking pin in conjunction with the transverse slot or the passage slot in the support screw causes a rotation lock, wherein further a sliding path of the support screw is maintained in consideration of the length of the passage slot.

With the help of the compression screw, it is also possible to achieve a relative movement between the bearing screw and nail, with the compression screw on the locking pin, which is already screwed, supported.

Fig. 8 shows a support nail 21 with a Tragnagelspitze 22 and a Tragnagelkopf 23. The support nail has a profiled shaft 24 which is formed in this case in the form of a cross profile. The cross profile is shown in the adjacent cross section. Although not shown in the figure shown here, the support nail may additionally have the passage slot 9 already mentioned. The support pin 21 thus formed corresponds to the embodiment of the femur nail shown in FIG. 9 with a profile bore 25 in the form of a cross slot.

The femur nail has in the embodiment shown in Fig. 9 in addition to the already mentioned cannulation 6, the bore 7 with the corresponding internal thread and the blind hole 10 and therefore can additionally receive the locking pin 8. In the case of a through slot introduced into the support nail, the securing pin in this case does not serve to prevent rotation, but to prevent slipping of the support nail or to limit the sliding path in the cross-slot bore of the femoral nail.

The support nail shown in Fig. 8 is inserted and guided in the Phillips hole and driven in the thus secured against rotation manner through the Phillips hole. Fig. 10 shows an inserted into the corresponding profile bore 25 Tragnagel 21 with its profile shank 24th The illustrated embodiments can be modified within the scope of expert action. Further exemplary embodiments emerge in particular from the subclaims.

LIST OF REFERENCE NUMBERS

1 Femurnagei

2 curvature

3 slot

drilling

Thigh ha Istrag screw

Cannulation in the nail

Bore with internal thread

safety pin

Through slot

10 blind hole with internal thread

11 Cannulation of the carrier screw

12 self-tapping thread

13 threaded hole

14 Compression screw 5 Bevel 6 Groove 7 Conical tip 8 External thread 9,20 Inner polygon 1 Support nail 2 Trennagelspitze 3 Tragnegelkopf 4 Profilschaft 5 Profilbohrung

Claims

claims

1. Proximal femoral nail (1) with in a bore (4) recorded self-tapping Henkelhalstragschraube (5) and insertable at the proximal end in Nagelkopflängsrichtung locking pin (8) and at least one provided at the distal end locking bore, characterized in that the support screw (5) a passage slot (9) extending over a longitudinal section and at the end of the support screw (5) opposite the self-tapping thread (12) have a threaded bore (7) extending in the longitudinal axis direction for receiving a compression screw (14) with an external thread complementary to the threaded bore (7) has, the bore for receiving the locking pin (8) in Nagelkopflängsrichtung over the area for receiving the support screw (5) is guided, wherein the locking pin (8) in the inserted state penetrates the through slot (9) and thereby a rotational securing of the support screw (5 ) causes, with pressing the compression screw (14) into abutment with the part of the securing pin (8) located in the passage slot (9), so that a relative movement between the femoral neck support screw (5) and the femoral nail (1) can be generated.

2. femoral nail according to claim 1, characterized in that it has a continuous in Nagelkopflängsrichtung bore (6).

3. femoral nail according to claim 1 or 2, characterized in that the support screw (5) has a through bore (11).

4. femur nail according to one of the preceding claims, characterized in that the support screw (5) at the end for receiving the compression screw (14) has a slope (15).

5. femur nail according to one of the preceding claims, characterized in that the locking pin (8) has a pin shape with a conical tip (17) and stepped diameter, wherein in the region of the external thread (18) has a blind hole with Innenvielkant (19, 20) for receiving a tool is formed.

6. femur nail according to one of the preceding claims, characterized in that the compression screw (14) is designed as a grub screw.

7. femur nail according to any one of the preceding claims, characterized in that the locking hole provided at the distal end is formed as a slot (3).