WO2008061802A1

WO2008061802A1 - Orthopaedic securing device and device for correcting a spinal column deformation

Info

Publication number: WO2008061802A1
Application number: PCT/EP2007/010260
Authority: WO
Inventors: Peter Brehm
Original assignee: Peter Brehm
Priority date: 2006-11-24
Filing date: 2007-11-26
Publication date: 2008-05-29
Also published as: DE102006055599B4; DE102006055599A1

Abstract

The invention relates to an orthopaedic securing device that can be secured to the vertebra and which comprises a cable guide that is configured for guiding and fixing a first cable part, and a cable clamp that is configured for clamping said cable part to the second end. Said cable clamp can comprise a cable guide for an additional cable part. Said orthopaedic securing device can be used in a device for correcting a spinal column deformation and comprises cable parts, that can be pretensed between, respectively two orthopaedic securing devices.

Description

ORTHOPEDIC MOUNTING DEVICE AND DEVICE FOR CORRECTING SPINAL DEFORMITY

The present invention relates generally to devices that may be used in orthopedic surgery, and more particularly to devices for correcting spinal deformity.

In patients with vertebral deformity, it may be necessary to surgically transform the spine into a physiological form. Spinal deformity may be in the form of scoliosis, i. a deformity with fixed sideward deflection, torsion of the vertebrae and rotation of the axis organ, as well as in the form of a kyphosis, i. an excessively pronounced dorsal convex shape of the spine.

In an operation to correct scoliosis, initially the curved spinal segments are straightened. The spinal segments are stiffened by creating a bone wound. By attaching bone material then creates a firm bony structure of the spinal column segment, which can withstand mechanical stress and thereby prevent re-curvature of the spine. If the stiffening is performed on the thoracic spine or the upper lumbar spine, this is usually perceived by patients to be less restrictive, since the mobility of the healthy spine in this area is restricted by the thorax. Stiffening of the spinal column in the area of the lower lumbar spine can be partially compensated by the mobility of the hip joint.

Metal implants may be used to stabilize the correction made during surgery, especially in the initial phase during which bony union occurs.

Such prior art metal implants may include rods that are secured along the patient's spine. Often the metal rods are used in pairs, with a bar attached to each of the right and left sides of the spine. The attachment of the rods may be by hooks, transpedicular screws or sublaminar wires connected to the spine. During the operation, the spine of the patient must be aligned as straight as possible and the implant adjusted so that it keeps the spine as straight as possible, otherwise it can lead to a crooked merging of the stiffened spinal segments and thus to a new deformity of the spine. For this purpose, it has been proposed to provide the rods with a thread. On each rod fasteners, which are equipped with a matching mating thread, can be screwed. The fasteners are then connected by screws or other fasteners to the vertebral bones of the patient. Depending on how far the fasteners are threaded onto the threaded rod, suitable distances between the vertebral bones to which the fasteners are attached may be adjusted to straighten the spine. As a result, a scoliosis can be corrected and / or a kyphosis can be set to a physiologically acceptable value. As an alternative to implants with a threaded rod, it has been proposed to use smooth metal rods to which clamp-shaped fasteners can be clamped, which in turn can be connected by screws or other fasteners to the vertebral bones.

A disadvantage of the prior art implants is that the distances between the vertebral bones must be adjusted in a predetermined order, along the rods, in the direction from the hip of the patient to his head, in the opposite direction or from the Stabmitte starting in hips or head direction. If the position of a central connecting element, on the two sides of which other connecting elements were already attached and connected to vertebral bones, were subsequently changed, this would result in a simultaneous change of distances between vertebrae on both sides of the connecting element. For example, if the distance between the vertebra to which the connector is attached and an inferior vertebra were reduced by sliding the connector along the rod, the distance to another superior vertebra would increase simultaneously. A correction of a faulty arrangement of vortices on one side of the connecting element would thus result in a correct arrangement of the vortices on the other side being lost. Therefore, in implants of the prior art, the positions of the vertebrae are sequentially defined along the rods, which may lead to lack of flexibility and severely limited possibilities for error correction. Another disadvantage of the prior art implants is that the placement of the fasteners along threaded rods may be cumbersome and may require great manual skill of the surgeon. In the case of implants with smooth rods, correct positioning of the connecting elements can be simpler than with implants with threaded rods, but it can occur with such implants that the connecting elements slip during or after the operation along the rods.

It is an object of the present invention to provide devices with the aid of which the abovementioned disadvantages can be avoided.

According to one aspect of the present invention, this object is achieved by an orthopedic fastening device which is attachable to a vertebral bone and a cable guide, which is designed to guide a first cable piece and a cable clamp, which is designed for clamping a second cable piece comprises.

To correct a spinal deformity, the fastening device can be attached to a vertebral bone. Through the cable guide and the cable clamp ropes can be tensioned to other fastening devices that are attached to other vertebral bones. Through the rope clamp while a length of a tensioned rope can be determined. Because of the deformability of the rope in the transverse direction, the rope in the rope clamp can be stably clamped without the risk of slipping of the rope. Further, a pre-bending, as is the case with bars, is not necessary. The fastening device according to the present invention makes it possible, in particular, to tension a rope piece in each case between a pair of vertebral bones. For this purpose, a piece of rope can be passed through the cable guide of a fastener and clamped in the cable clamp of a second fastener to another vertebra. In the cable guide of the second fastener, a second rope piece can be inserted and stretched to a third fastener to another vortex. The arrangement of two vertebral bones can be adjusted by setting the length of a piece of rope that connects these two vertebral bones together. Thus, the relative orientation of the two vertebral bones can be independent of the relative orientation of other pairs of vertebral bones. The relative alignment of two vertebral bones can be subsequently corrected by loosening a cable clamp and changing the clamped cable length, without the alignment of other vertebral bones already being lost being lost. Alternatively, a einziαes - A -

continuous rope piece between two or more fastening devices are tensioned, wherein the rope piece is inserted into the cable guide of a fastening device and clamped in the cable clamps of the other fastening devices.

Suitably, the fastening device comprises a first screw which can be screwed into the vertebral bone. The first screw allows a stable and permanent connection between the fixation device and the bone.

The first screw may in some embodiments of the invention comprise a screw head having a recess. The fastening device comprises a component which can be inserted into the recess and fixable in the recess. The cable guide comprises an opening in the component, which is designed to pass through the first cable piece. Since in such embodiments the cable guide can be accommodated in a space-saving manner in the screw head, the fastening device requires only a relatively small volume in the body of the patient. As a result, adverse effects of the fastening device on adjacent organs of the patient can be reduced. In addition, so the rope can be fastened close to the vertebral bones, so that leverage forces that can lead to a loosening of the fastener can be reduced.

The cable clamp may comprise a groove formed in the component and a second screw. The second screw is in a direction perpendicular to a direction in which the groove in the recess in the component is perpendicular, screwed into a thread in the screw head of the first screw threaded. This construction makes it possible to attach the cable clamp at a small distance to the vertebral bone, whereby leverage can be reduced and a space-saving design of the fastening device can be achieved.

The thread may be attached to side surfaces of the recess in the screw head of the first screw, so that the component is fixed when screwing the second screw of the second screw in the recess. This allows a fixation of the component and a clamping of the rope in the cable clamp take place simultaneously, whereby the time required for insertion of the fastening device into the body of the patient work can be reduced.

Suitably, a thread of the second screw is formed such that a normal direction to a surface of the thread on the in the Recess inserted component side facing away from an axis of the thread of the second screw is inclined. By such a shape of the thread, a force acting from the component to the screw, so transferred to the thread in the screw head of the first screw, that substantially no force component is formed, which presses apart the two parts of the screw head side of the recess. As a result, it can be prevented that the screw head is spread apart and the second screw slips out of the screw head of the first screw.

According to another aspect of the present invention, a spinal deformity correcting device comprises at least two fastening devices, wherein at least a first one of the fastening devices is a fastening device having the features described above. Furthermore, the device comprises a first cable piece, wherein the first cable piece can be guided by the cable guide of the first fastening device and can be tensioned to a second of the at least two fastening devices.

By using rope pieces, some flexibility of the device can be maintained when the device is mounted in the body of a patient. This may be advantageous when, in addition to the device according to the present invention, another device is used, e.g. an implant in which spacings between fasteners mounted in vertebral bones are adjusted by rigid rods. In this case, the device according to the present invention can be used to provisionally stabilize the spine. When inserting the implant, the spine is then already aligned, so that the alignment of the vertebrae no longer has to be carried out with the help of rigid rods.

In some embodiments, the device comprises at least three attachment devices and a second cable section, wherein the second cable section can be clamped by a third of the attachment devices to the first attachment device and clamped by the clamping device of the first attachment device. By using two or more pieces of rope, each clamped between a pair of fasteners, an individual adjustment of the distances between the fasteners is made possible. This allows a particularly precise straightening of the spine. Suitably, the first rope piece has an anchor adapted to prevent slippage of one end of the first rope piece through the rope guide. As a result, the cable piece can be tensioned without it having to be separately fixed to the first fastening element. This can simplify the insertion of the device.

Suitably, all fasteners are fasteners of the type described above. This can reduce the expense of manufacturing the vertebral deformity correcting device because fewer different parts need to be made.

Each piece of rope may have at one end an anchor adapted to prevent slippage of the end of the rope through the rope guides of the attachment elements. As a result, the tensioning of the rope pieces can be simplified.

The anchor may comprise a mushroom-shaped member which is connected to the rope piece.

Each piece of rope can have, in addition to the anchor, a structure which can be latched in the cable guide. The latchable structure makes it possible to temporarily fix the end of the rope piece to which the anchor is attached in the rope guide so that it can not slip back while the other end is fastened in the rope clamp of another fastening element. This can reduce the risk of errors during the operation.

In some embodiments of the invention, each rope piece may comprise a wire rope and the latchable structure may include a pinch of the wire rope.

The device for correcting a spinal deformity may additionally comprise one or more supplements, wherein each of the supplements is attachable to a vertebral bone and has an opening through which one of the attachment devices can be guided. The supplements allow a force acting from the fasteners on the vertebral bones to be distributed over a larger area. As a result, a mechanical load on the bone can be reduced. In addition, the openings may define appropriate positions of the fasteners, thereby simplifying attachment of the fasteners. Each of the supplements may have at least one second opening, through which a further fastening device can be guided. Thereby, in embodiments of the present invention in which in addition to the device with cables a rigid rod implant is used, a relative arrangement of the fastening devices according to the present invention and the further fastening devices can be specified. This can reduce the risk of errors during the operation.

The openings may comprise a spherical bearing surface for a portion of the fastening device passed through the opening. Thereby, a direction in which the fastening devices are inserted into the vertebral bones can be varied. This allows individual adaptation of the fastening device to the anatomy of the patient.

Each of the supplements may include one or more staples that can be wrapped in the vertebral bones. As a result, the risk of slippage of the inserts before the onset of the fastening devices can be reduced.

Each of the supplements may have a side which can be placed on the vertebral bone, wherein the side which can be placed on the vertebral bone is convex in a first direction and concave in a second direction, wherein the supplements are fixable to the vertebral bone such that the first direction is in a spinal axis direction runs and the second direction is in a vortex circumferential direction. This allows a good adaptation of the shape of the inserts to the shape of the human vertebral bone can be achieved.

The openings of the inserts may be adapted to guide the fasteners in directions skewed towards each other. As a result, it can be prevented that a fastening device, when inserted into the vertebral bone, strikes another fastening device inserted in the same vertebral bone.

According to a further aspect of the present invention, a device for correcting spinal deformity comprises at least two attachment devices, each of the attachment devices being attachable to a vertebral bone and a first cable section. The first rope piece can be tensioned by a first of the at least two fastening devices to a second of the at least two fastening devices. Through the use of ropes to correct spinal deformity, a degree of flexibility of the device can be achieved which can be beneficial in deploying a second device that may contain rigid rods. In addition, rope pieces can be fixed more stably than smooth bars due to their deformability in the transverse direction.

In some embodiments, the device comprises at least three attachment devices and a second cable element that can be tensioned by the second attachment device to a third attachment device. By using individual lengths of rope tensioned between each two of the attachment devices, the distance between each pair of attachment devices can be made independently of the setting of the distances between other pairs. Also, the surgeon is not bound to a particular order of fixation of the vertebral bones. As a result, an improved accuracy of the alignment of the spine can be achieved.

In other embodiments, the device comprises at least three attachment devices, and the first cable piece is tensionable from the first attachment device to all other of the at least three attachment devices. Thereby, the handling of the device can be simplified because the surgeon must handle with fewer items than in embodiments in which a separate piece of rope is stretched between each pair of fasteners.

Further embodiments of the present invention will be described with reference to the accompanying drawings. Show it:

1a is a schematic perspective view of a device for correcting spinal deformity according to an embodiment of the present invention;

Fig. 1b is a schematic cross-sectional view of the device shown in Fig. 1a;

Fig. 1c is a schematic plan view of the apparatus shown in Figs. 1a and 1b;

FIG. 2a shows a schematic perspective view of a component of a fastening device used in the device shown in FIGS. 1a to 1c; FIG.

2b is a schematic cross-sectional view of a screw which is used in the device shown in FIGS. 1a to 1c. 3 is a schematic perspective view of a supplement that may be used in a device according to an embodiment of the present invention; and

Fig. 4 is a schematic perspective view of a supplement which may be used in a device according to another embodiment of the present invention.

FIG. 1 a shows a schematic cross-sectional view of a device 100 for correcting a spinal deformity according to an embodiment of the present invention. A schematic cross-sectional view of the device 100 and a schematic plan view of the device 100 are shown in FIGS. 1b and 1c.

The device 100 has a plurality of fastening devices 101, 102, 103 and cable pieces 113, 114. The structure of the fastening devices 101, 102, 103 will be explained using the example of the fastening device 102. The fastening device 102 comprises a first screw 107 with a screw head 124 and a thread 160. The first screw 107 can be screwed into a vertebral bone of a patient, for example into a vertebral body. For this purpose, the thread 160 may comprise the configuration of a thread of a bone screw of a type known to those skilled in the art.

In the screw head 124, a recess 125 is provided, into which a component 108 can be inserted. The component 108 may have an elongated shape and protrude laterally beyond the edge of the screw head 124. As a result, a rotatability of the component 108 inserted into the recess 125 relative to the first screw 107 can be substantially prevented. In side surfaces 150, 151 of the recess 125, a second thread is cut into which a second screw 109 can be screwed. When the second screw 109 is screwed into the second thread, the component 108 is fixed by the second screw 108 in the recess 125.

A schematic perspective view of the component 108 is shown in FIG. 2a. The component 108 has on its side surfaces on a first projection 140 and a second projection 141. The projections 140, 141 may have a rounded shape, which is adapted to an inner diameter of the second thread in the recess 125. Thus, the component can be inserted from above into the recess 125, wherein the projections 140, 141 transverse to the thread of the second thread through the second Threaded and prevent accidental slipping out of the component 108 in the lateral direction of the recess 125.

The component 108 further comprises an opening 143, which is provided in the form of a through bore through the component 108 and for the passage of one of the cable pieces 113, 114, for example, the cable piece 114, is formed. Thus, the opening 143 forms a cable guide 119 which is adapted to guide the cable 114. Above the opening 143 there is a bore 147 which extends through the component 108 substantially parallel to the opening 143. In a middle region of the component 108 there is a recess 146, which intersects the bore 147, so that the bore 147 continues in the region of the recess 146 in the form of a groove 142 at the bottom of the recess 146. Laterally of the recess 146, the bore 147 extends through parts 144, 145 of the component 108.

When the component 108 is inserted into the recess 125 in the screw head 124 of the first screw 107, an axis of the thread cut in the side surfaces 150, 151 of the screw head 124 is perpendicular to a direction of the groove 142, so that the second screw 109 when screwed into the thread is guided into the recess 146 in the component 108 and strikes the groove 142.

The second screw 109 and the groove 142 form a cable clamp 120, which is designed for clamping one of the cable sections 113, 114, in particular of the cable section 113. For this purpose, the cable piece 113 can be inserted through the bore 147 so that it lies in the region of the recess 146 in the groove 142. The areas of the bore 147 which pass through the parts 144, 145 of the component 145 thereby guide the cable piece 113 and prevent the cable piece 113 from falling out of the groove 142. Subsequently, the second screw 109 can be screwed into the screw head 124 of the first screw 107 and tightened. In this case, an end of the second screw 109 facing the component 108 presses on the part of the cable piece 113 lying in the groove 142 and thus clamps the cable piece 113 firmly.

At the same time, the second screw 109 prevents the component 108 from being able to be removed upward from the recess 125 in the screw head 124 of the first screw 107 and thus fixes the component 108 in the recess 125. The second screw 109 thus serves both for clamping the cable piece 113 as well as for fixing the component 108. Advantageously, thereby the number of to assemble the Device 100 required for the correction of a spinal defect can be reduced.

However, in other embodiments of the present invention, the fixation of the member 108 and the clamping of the cord 113 may be accomplished by means of various screws. For this purpose, a third screw can be inserted into the component 108, which strikes the groove 142 when screwed in, thereby clamping the cable piece 113.

In some embodiments of the present invention, the fasteners 101, 103 may be constructed substantially the same as the fastener 102 described above. Specifically, in such embodiments, the fastener 101 includes a first screw 104 having a screw head 152 including a recess 154 into which Component 105 can be used and fixed with a second screw 106, and a cable guide 117 and a cable clamp 118. The fastening device 103 comprises a first screw

110 with a screw head 153 having a recess 155 in which a component

111 can be used and fixed with a second screw 112. In addition, the fastening device 103 has a cable guide 122 and a cable clamp 123.

In other embodiments, the device 100 may include various attachment devices. For example, in a first of the fastening devices 101, 102, 103, e.g. the fastening device 101, the cable clamp are omitted and in a last of the fastening devices 101, 102, 103, e.g. the fastening device 103, the cable guide are omitted. In further embodiments, instead of the cable guide 117, a permanent attachment of the cable section 113 to the fastening device 101 may be provided. For example, the cable piece 113 may be welded to the fastening device 101.

FIG. 2b shows a schematic cross-sectional view of the second screw 109 of the fastening device 102 in an embodiment of the present invention. The second screw 109 includes an external thread 160 having a thread 161. The thread 161 has a first surface 165 on a side remote from the component 125 inserted into the recess 108 and a second surface 166 on a side facing the inserted component 108. A normal vector n of the first surface 165 is to an axis 162 of the external thread 160 inclined. The thread in the screw head 125 of the first screw 107 is formed as a counter thread to the thread of the second screw 109.

When a force F acts on the second screw 109 in the direction from the member 108 to the second screw 109 due to, for example, the tension of a cord inserted in the cable guide 119 or the cable clamp 120, the force F has a force component Fs parallel in one direction to the first surface 165, and a force component Fp acting in the direction of the normal vector n. The force component Fp is transmitted from the second screw to the thread in the screw head 125 of the first screw, but not the force component Fs. When the normal vector n is inclined toward the axis of the thread 160, the force component Fp also acts in this direction. Thereby, the side surfaces 150, 151 of the recess 125 are attracted to the second screw 109. Thus, it can be avoided that the side surfaces 150, 151 are spread apart, which could lead to a relaxation or even a loosening of the second screw 109.

The second screw 109 may have a bore 163 in its center, with an axis of the bore 163 coinciding with the axis 162 of the thread 160. Inside the bore projections 164 may be provided. Thus, a suitably shaped screwdriver can be inserted into the bore 164 and used to loosen and tighten the second screw 109.

In embodiments of the invention, the cable pieces 113, 114 may comprise a wire rope. The first screws 104, 107, 110, the second screws 106, 109, 112 and the components 105, 108, 111 may be formed of titanium or a titanium alloy, for example Ti6Al4V.

The cord 113 may, in some embodiments of the present invention, comprise at one end an anchor 115, which may for example be provided in the form of a mushroom-shaped member attached to the end of the cord 113. In embodiments of the present invention in which the rope piece 113 comprises a wire rope, the anchor 115 may be welded to the rope piece 113. The armature 115 may have a diameter which is greater than the diameter of the cable guides in the fastening devices 101, 102, 103.

When the cable piece 113 is guided by the cable guide of one of the fastening devices 101, 102, 103, for example by the cable guide 117 of Fixing device 101, the anchor 115 prevents the end of the rope piece 113, on which the anchor 115 is mounted, slipping through the cable guide. Thus, the cable piece 113 can be inserted through the cable guide of one of the fastening devices 101, 102, 103 and stretched to another of the fastening devices 101, 102, 103, where it can be clamped in the cable clamp of the other fastening device.

Similar to the rope piece 113, the rope piece 114 also has an anchor 116, which may be provided in the form of an anchor fastened to one end of the rope piece 114. Thus, the rope piece 114 can also be tensioned by one of the fastening devices 101, 102, 103 to another of the fastening devices 101, 102, 103.

In addition to the anchors 115, 116, the cable pieces 113, 114 may have structures which can be latched into the cable guides 117, 119, 122 of the fastening devices. The structures can be designed such that the latching is reversible. In embodiments of the present invention in which the cable pieces 113, 114 comprise wire ropes, the snap-in structure of a cable piece 113, 114 in the form of a pinch of the cable piece 113, 114 can be provided. As those skilled in the art know, a pinch of a wire rope can be made by compressing a portion of the rope piece with a high pressure so that the rope piece plastically deforms in that part.

In the crimped area, the rope piece 113, 114 may have a smaller dimension in the direction in which it was squeezed than a diameter of a non-crimped portion of the rope piece 113, 114, while a dimension of the rope in a direction perpendicular to the crimping direction may be greater than the diameter of the non-crimped portion of the rope piece 113, 114 may be. When the diameter of non-crimped portions of the cord 113, 114 is designed to fit straight through the cable guides 117, 119, 122, insertion of the crimped portions of the tows 113, 114 into the cable guides 117, 119, 122 may become elastic Deformation of the cable pieces 113, 114 lead in this area, are pressed by the parts of the crimped areas against the inner walls of the cable guides 117, 119, 122. In this case, frictional forces occur, which hinder the passage of the bruises through the cable guides 117, 119, 122, so that the bruises engage and prevent unintentional slipping back of the cable sections 113, 114. With a However, certain bruises can be removed from the cable guides 117, 119, 122 again, so that the latching is reversible.

The present invention is not limited to embodiments in which, as described above, between each of a pair of Befestigungsvoπrichtungen 101, 102, 103, a piece of rope is stretched. In other embodiments, instead of the two cable pieces 113, 114 a single piece of rope may be provided. The single rope piece may have at one end an anchor similar to the anchors 115, 116 of the first rope piece 113 and the second rope piece 114. In addition to the armature, a structure which can be latched into a cable guide can furthermore be provided, for example in the form of a pinch of the individual cable piece.

The single rope piece can be inserted into the cable guide of one of the fastening devices 101, 102, 103, for example into the cable guide 117 of the fastening device 101. The end of the individual cable piece, which is not equipped with an anchor, can then pass through the cable clamps of one or more further fastening devices, such as the cable clamps 120, 123 of the fastening devices 102, 103 inserted and clamped in this by tightening the second screws 109, 112.

The number of attachment devices in a vertebral deformity correction device need not be three, as shown in Figs. 1a to 1c. In other embodiments of the present invention, a larger number of fasteners may be provided. In such embodiments, more than two rope pieces may be provided, wherein the number of rope pieces may be one less than the number of fastening devices, so that each of the rope pieces can be tensioned between two of the fastening devices. The number of fastening devices may be greater than or equal to the number of vertebrae in the vertebral column portion to be stiffened, so that at least one fastening device can be inserted into each of the vertebrae.

In embodiments of the present invention in which a single rope piece is used instead of the rope pieces 113, 114, two or more attachment devices may be provided, wherein the number of attachment devices may be greater than or equal to the number of vertebrae in the spinal column portion to be stiffened. The length of the individual rope piece can be adapted to the length of the spinal column portion to be stiffened, wherein in the Stiffening a larger spine section using a larger number of fasteners, using a longer length of rope than using a short spine section using only a short length of rope.

Device 100 may be used to correct spinal deformity, such as scoliosis, in the following manner. First, access to the patient's spine is created. Depending on the area in which the spine is crooked, the procedure can be performed via a ventral access (on the ventral side) or a dorsal approach (on the back side). In some cases, a combination of a ventral and a dorsal procedure may also be used. Ventral procedures are often used to correct thoracolumbar spine deformity, while dorsal procedures are performed for lumbar interventions. Subsequently, the spine of the patient is exposed and the vertebral arch joints in the area to be stiffened are cartilaginous. Thereafter, the device according to the present invention can be used.

First, the first screws 104, 107, 110 of the fastening devices 101, 102, 103 are screwed into the vertebral bones of the patient. Depending on the size of the region of the spinal column to be corrected, it is possible to use a different number of fastening devices, it being possible to attach a fastening device to each vertebra in the vertebral column portion to be corrected. A tool for screwing in the first screws 104, 107, 110 can be applied either in the recesses 154, 125, 155 or at flattened attachment points, which can be provided along peripheral surfaces of the screw heads 152, 124, 153.

After inserting the first screws 104, 107, 110, the components 105, 108, 111 can be inserted into the recesses 154, 125, 155 and fixed with the second screws 106, 109, 112 and the cable pieces 113, 114 can be inserted between the fastening devices 101, 102, 103 are stretched.

For this purpose, first a piece of rope, for example, the rope piece 113, inserted through the cable guide 117 a fastening device, such as the fastening device 101 and pulled through this until the armature 115 rests against the component 105 and further movement of the rope piece 113 through the cable guide 117th prevented. The latchable structure can thereby engage in the cable guide 117, so that the cable piece 113 is provisionally fixed to the fastening device 101 and unintentional slipping back of the cable piece 113 is prevented.

Thereafter, the end of the rope piece 113 not equipped with the anchor 115 may pass through the cable clamp 120 of another attachment device, e.g. the fastening device 102 are inserted. The second screw 109 of the fastening device 102 can not be completely tightened or even deployed at this stage, so that the cable piece 113 can be moved through the cable clamp 120. Then, the rope piece 113 can be fixed provisionally by tightening the second screw 109.

Similar to the rope piece 113, further rope pieces can be tensioned between the fastening devices 102, 103. For example, the cable piece 114 can be guided through the cable guide 119 of the fastening device 102 and temporarily fixed in the cable clamp 123 of the fastening device 103.

The patient's spine can then be straightened, e.g. by the surgeon or an assistant moving the patient. In patients with a severely deformed spine, a less curved spinal column may be used instead of straightening the spine to avoid overstretching the spinal cord and resulting neurological complications.

After the desired alignment of the spine is adjusted, the second screws 109, 112 of those fastening devices 102, 103, in the cable clamps rope pieces 113, 114 were clamped, loosened or loosened, so that the ends of the cable pieces 113, 114 in the cable clamps 120th , 123 can be moved. The rope pieces can be pulled so far through the cable clamps 120, 123, that they are taut at the desired orientation of the spine and then clamped by tightening the second screws 109, 112.

Alternatively, the cable pieces 113, 114 may also be inserted into the cable clamps 120, 123 after the desired alignment of the patient's spine has been adjusted. As a result, the provisional fixing of the cable pieces 113, 114 is unnecessary. The cable pieces 113, 114 prevent movements of the spine of the patient, in which the distance between the fastening devices 101, 102, 103 increases, so that a train on the cable pieces 113, 114 is exercised. Movements in the opposite direction, in which the distance between the fastening devices 101, 102, 103 increases and lateral movements, however, may still be possible. An arrangement of the fastening devices 101, 102, 103 may be chosen such that the device 100 prevents a deformation of the spine in the deformed state. Alternatively, several devices according to the present invention may be used to stabilize the spine in multiple directions. For example, one device 100 may be deployed on the left side of the spine and another device 100 on the right side of the spine such that the spine is stabilized against lateral deflections such as occur with scoliosis.

If it is determined in a subsequent control of the shape of the spine that the deformation of the spine has not been corrected as desired, the cable clamps in one or more of the fastening devices 101, 102, 103 by loosening one or more of the second screws 106, 109, 112 are opened and the rope clamped in the cable clamps to be repositioned to improve the correction of the deformation. However, pieces of rope that are in parts of the spine where the deformation has already been corrected sufficiently may remain clamped. Thus, the correction of the deformation in individual sections of the spine can be specifically improved.

When the deformation of the patient's spine has been corrected as desired, a prior art implant can be used in which the patient's vertebral bones are connected by rigid rods. Since the patient's spine is already held in the desired shape by the device 100 according to the present invention, it is no longer necessary to align the spinal column of the patient with the aid of the implant.

As already explained above, even after the attachment of the cable sections 113, 114, a certain mobility of the vertebral bones connected to the device 100 may exist, since the cable sections 113, 114 only prevent movements of the spinal column in which the distance between the fastening elements 101, 102, 103 enlarged. This residual mobility of the spine may facilitate insertion of the implant. After insertion of the implant, the device 100 according to the present invention may be removed. For this purpose, first the second screws 106, 109, 112 can be loosened and removed. Subsequently, the cable pieces 113, 114 and the components 105, 108, 111 can be removed. Finally, the first screws 104, 107, 110 can be unscrewed from the patient's vertebral bones.

Alternatively, the first screws 104, 107, 110 may remain in the body of the patient. In such embodiments, the device 100 may include rigid rods that may be inserted into the recesses 154, 125, 155 instead of the components 105, 108, 111 and the cable pieces 113, 114. An attachment of the rigid rods can be done by tightening the second screws 106, 109, 112.

In still other embodiments of the present invention, the cable pieces 113, 114 may be configured to remain in the body of the patient. In such embodiments, the cable pieces 113, 114 may include implant steel, titanium, or a titanium alloy.

As the experts know, bone chips can be inserted into the cartilaginous areas of the vertebral arch joints. The bone chips can be removed, for example, from the iliac crest of the patient. This can accelerate the ossification of the patient's spine in the area where the deformation has been corrected. This can further enhance the stiffening of certain portions of the patient's spine caused by the implant. Finally, the access to the patient's spine is closed and sutured.

The first screws 104, 107, 110, in some embodiments of the invention, may be configured to be inserted into the vertebral bones of the patient without inserts being placed between the screw heads 152, 124, 153 and the vertebral bones. However, inserts may be used in other embodiments.

FIG. 3 shows a schematic perspective view of a supplement 300 that may be used in a vertebral deformity correction device according to the present invention.

The supplement 300 comprises a plate 301, which is designed to rest on a vertebral bone of a patient. For this purpose, the plate 301 on a bottom, the facing away from the viewer in the perspective of Fig. 3, have a shape that is adapted to the shape of a human vertebral bone. Thus, the plate can be designed to be convex parallel to the spine axis and concave in the direction of the vortex circumferential direction.

Clamps 306, 307, 308, 309 adapted to be wrapped in the vertebral bones of the patient may be attached to the plate 301. As a result, the supplement 300 can be fixed on the vertebral bone, so that unintentional slipping of the supplement 300, in particular during assembly of the device 100, can be avoided.

An opening 302 is formed in the plate 301, the diameter of which is such that one of the first screws 104, 107, 110 can be guided through the opening 302 and screwed through the opening 302 into the vertebral bone of the patient.

On an upper side of the plate 301, which faces the observer in the perspective of FIG. 3, a spherical bearing surface 303 for the fastening devices 101, 102, 103 may be provided. When one of the first screws 104, 107, 110 is passed through the opening 302 and screwed into the patient's vertebral bone, the portion of the screw head 152, 124, 153 facing the vertebral bone rests on the spherical bearing surface 303. Because of the symmetry of the spherical bearing surface, the screw head 152, 124, 153 can rest on the spherical bearing surface 303 at different orientations of the first screw 104, 107, 110. As a result, an orientation of the first screw inserted into the opening 303 can be varied. As a result, the arrangement of the first screw in the vertebral bone can be adapted flexibly to the individual anatomy of the patient.

In other embodiments of the present invention, instead of the spherical bearing surface 303, a planar support surface may be provided. In such embodiments, the opening 302 may be configured to guide a first screw of one of the fastener devices 101, 102, 103 inserted into the opening 302 in a predetermined direction relative to the shim 300. This may help prevent incorrect insertion of the first screw in the supplement 300 to avoid. The plate 301 of the shim 300 may have a recess in the vicinity of the opening 302. This allows the head of a. placed in the insert 300 at a closer distance to the patient's vertebral bone than in embodiments of the present invention in which the insert 300 is not recessed.

In some embodiments, the garnish 300 may include bores 304, 305 that pass from the top of the garnish 300 to the underside thereof, for example, to receive an instrument to position the garnish.

4 shows a schematic perspective view of a supplement 400 that according to another embodiment of the present invention can be used in a device for correcting spinal deformity. The insert 400 comprises a plate 401. On an underside of the plate 401, which faces away from the viewer in the perspective of FIG. 4, brackets 407, 408, 409 and another, in Fig. 4 hidden by the plate 401 clip attached , Each of the clamps may be attached to a corner of the plate 401. The staples may be insertable into a vertebral bone and configured to fix the insert 400 to the vertebral bone. A shape of the underside of the plate 401 may, as in the embodiment described above with reference to FIG. 3, be adapted to the shape of a human vertebral bone to improve mechanical contact between the sheath 400 and the vertebral bone.

In the plate 401, a first opening 405 and a second opening 406 may be provided. One of the openings, for example the first opening 405, can be designed to insert one of the first screws 104, 107, 110 of the device 100. The other opening, such as the second opening 406, may be configured to pass through an attachment screw of an implant that is implanted in the patient's body after device 100 has been applied. For example, the implant may include rigid rods that firmly connect the patient's vertebral bones. In some embodiments of the present invention, a diameter of the implant fastening screws may be substantially identical to the diameter of the first screws 104, 107, 110 of the device 100, such that the first aperture 405 and the second aperture 406 may be substantially the same diameter , In such embodiments of the present invention, one of the first screws 104, 107, 110 may be selectively inserted into the first opening 405 or the second opening 406. In other embodiments, a diameter of the first screws 104, 107, 110 may differ from a diameter of the fastening screws of the implant. In such embodiments, the openings 405, 406 may have a different diameter such that the first screws 104, 107, 110 of the device 100 first used in the course of the operation only fit through the larger of the openings 405, 406. This may help to prevent erroneous insertion of the first screws 104, 107, 110.

The openings 405, 406 may have spherical bearing surfaces 402, 403. This allows screws to be screwed in different directions into the patient's vertebral bone. In other embodiments, a planar support surface may be provided instead at one of the openings 405, 406 or at both openings 405, 406.

The openings 405, 406 may be configured to guide the screws inserted into the openings 405, 406 in directions skewed toward each other. For this purpose, the openings 405, 406 may be provided in the form of substantially cylindrical bores, with straight lines running along the axes of the openings 405, 406 being skewed towards each other. It can thereby be ensured that screws which are inserted into the openings 405, 406 and screwed into the vertebral bones do not meet inside the bone, which could prevent a complete screwing in of the last inserted screw.

Claims

An orthopedic fixation device attachable to a vertebral bone and comprising a cable guide adapted to guide a first cable and a cable clamp adapted to clamp a second cable.

2. An orthopedic fastening device according to claim 1, comprising a first screw which can be screwed into the vertebral bone.

3. An orthopedic fastening device according to claim 2, wherein the first screw comprises a screw head having a recess, and wherein the fastening device further comprises a component which is insertable into the recess and fixable therein, wherein the cable guide comprises an opening in the component , which is designed for the passage of the first piece of rope.

The orthotic fastening device of claim 3, wherein the cable clamp comprises:

a groove formed in the component;

a second screw, which is screwed in one direction into a thread insertable in the screw head of the first screw, which is perpendicular to a direction in which the groove runs in the component inserted into the recess.

5. An orthopedic fastening device according to claim 4, wherein the thread is provided on side surfaces of the recess in the screw head of the first screw, so that the component is fixed when screwing the second screw of the second screw in the recess.

6. An orthopedic fastening device according to any one of claims 4 and 5, wherein a thread of the second screw is formed such that a direction normal to a surface of the thread on the side facing away from the component inserted into the recess to an axis of the thread of the second screw inclined is.

7. Apparatus for correcting spinal deformity, comprising: at least two fastening devices, wherein at least a first one of the fastening devices is a fastening device according to one of claims 1 to 6; and

a first rope piece, wherein the first rope piece can be guided by the cable guide of the first fastening device and can be tensioned to a second of the at least two fastening devices.

8. Device for correcting spinal deformity according to claim 7, comprising at least three attachment devices, additionally comprising a second cable section, wherein the second cable section can be clamped by a third of the attachment devices to the first attachment device and clamped by the clamping device of the first attachment device.

The vertebral deformity correcting device according to claim 7 or 8, wherein the first rope has an anchor adapted to prevent slippage of one end of the first rope through the rope guide.

A vertebral deformity correcting device according to any one of claims 7 to 9, wherein all the fixing devices are fixing devices according to any one of claims 1 to 6.

A vertebral deformity correcting device according to claim 10, wherein each rope piece has at one end an anchor adapted to prevent the end of the rope from slipping through the rope guides of the fastening elements.

The vertebral deformity correcting device according to any one of claims 9 and 11, wherein the armature comprises a mushroom-shaped member connected to the cord.

13. An apparatus for correcting spinal deformity according to any one of claims 11 and 12, wherein each piece of rope next to the anchor has a snap-in structure in the cable guide.

The vertebral deformity correction device of claim 13, wherein each rope piece comprises a wire rope and the latchable structure comprises a pinch of the wire rope.

15. The spinal deformity correction device of claim 7, further comprising one or more supplements, wherein each of the supplements is securable to a vertebral bone and has an opening through which one of the fixation devices is passable.

16. A spinal deformity correction device according to claim 15, wherein at least one of the supplements has a second opening through which a further attachment device can be guided.

A vertebral deformity correction device according to any one of claims 15 and 16, wherein the apertures comprise a spherical bearing surface for a portion of the fastener passed through the aperture.

The spinal deformity correction apparatus of any one of claims 15 to 17, wherein each of the supplements comprises one or more staples impactable in the vertebral bones.

19. Device according to one of claims 15 to 18, wherein each of the supplements has an attachable on the vertebral bone side, wherein on the vertebral bone can be placed side in a first direction convex and concave in a second direction, wherein the inserts so on the Fastening of the vertebral bone is that the first direction is in a spinal axis direction and the second direction is in a vertebral circumferential direction

20. The spinal deformity correction device of claim 16, wherein the apertures of the at least one shim are configured to guide the securement elements in directions skewed toward each other.

21. A spinal deformity correction device comprising:

at least two attachment devices, each of the attachment devices attachable to a vertebral bone; and

a first rope piece, which can be tensioned by a first of the at least two fastening devices to a second of the at least two fastening devices.

22. Spinal deformity correction device according to claim 21, having at least three fastening devices, additionally comprising a second rope piece, which can be tensioned by the second fastening device to a third of the fastening devices.

23. An apparatus for correcting spinal deformity according to claim 21, comprising at least three fastening devices, wherein the first cable piece can be tensioned by the first fastening device to all other of the at least three fastening devices.