SK279305B6 - Apparatus for correcting spinal deformations - Google Patents

Abstract

An apparatus contains at least two segments that are fixed to vertebras being mutually interconnected. Each segment (1) is attached at least to one vertebra by means of at least one gripping element (3) containing at least one spring (4) by means of which it is connected-via force closing-to at least one more segment (1') that is attached to at least one more vertebra. Connecting line of the spring's (4) ends forms an angle of 45 ° with the vertical axis of the vertebra in both frontal and saggital plane; in ventral and/or dorsal direction. Action of the force between particular segments, actuated thereupon by means of the spring (4), are transmitted to vertebras in the area of their deformations thus correcting thereof. The spring (4) might be firmly attached to both the segments or the firm attachment is provided on one segment only whereas the second, which is located in bearing case (5), has a pre-set movement.

Description

Technical field

The invention relates to a device for correcting the deformities of the spine based on metal implants, which is applied surgically.

BACKGROUND OF THE INVENTION

Spinal deformities are further understood to include scoliosis (spinal deflection in the frontal plane) and pathological kyphosis and lordosis (deflection in the sagittal plane). Operational correction of spinal deformities using metal implants, made of special stainless steel biocompatible steels and titanium alloys, is the most effective way of treating spinal deformities and at the same time a medical-technical problem that has been topical for nearly a century and has not been satisfactorily solved.

Several principal design solutions for implants for the treatment of spinal deformities are currently known, but each has a number of drawbacks in addition to certain advantages. The whole set of known solutions can be divided into three basic groups, which can be characterized as follows.

The first group is represented by a set of solutions that can be characterized as rigid systems. An essential feature of these systems is that they comprise at least one rod or plate which is operatively introduced into the spine deformation point substantially parallel to it and connected along its length to at least two vertebra vertebrae by differently shaped clamping elements (hooks, jaws, screws) , wire loops, etc.) mounted on it that attach to the vertebral body or projections. In general, two rods are used which are interconnected at at least two locations and are operatively installed on the sides of the spine, with more or all of the vertebral vertebrae attached thereto at the point of its deformity. From a functional point of view, the deformity is corrected by acting on the long vertebral spine of the transverse tensile and / or compressive forces on the deformed vertebrae, utilizing the rigidity of the bar or the bar. bars. These systems usually correct well and at the same time stabilize the spine in all three planes, but do not allow movement and growth of stabilized segments. When applied, the joints are therefore surgically abolished and bone grafts are applied to induce spinal growth (spondylodesis) at the site of deformity, thus locally preventing its growth and nullifying mobility. At present it is possible to include here as representatives eg. Wisconsin instrumentation [Drummond D. S. et al., J. Pediatr. Orthop., 4, 1984, 397-404; Drummond D. S., The Orthop. Clin. of North Am., 2, 1988, 281-289], Cotrel-Dubousset [Cotrel Y., Dubousset J., Rev. Chir. Orthop., 1984, 70, 489-495; Cotrel Y., Dubousset J., Orthop. Trans., 9, 1985, 118], TSRH, Isola system using rod in combination with splint [Asher MA et al. Isola dirt implant system: Principles and practice, AcroMed, Cleveland, 1991], Central-Stab-System, Luque instrumentation [Luque ER, Cardoso A., Orthop. Trans., 1, 1977,136; Luque E. R. Tailoring surgery to switch pathology, In Segmental Switching Instrumentation. Thorofare, N.J., Slack Co., 1984] and others. Internal fixators can also be included in this group (eg Socon [Socon-Fixateur Interne-Aesculap, Prospectus Nr. C-627 1091/3, Germany), Kluger fixator [DE P321957.3; Diek W. et al., Paraplegia 23, 1985, 225

232), Matzen Fixator [Intemal Fixator for the Lumbar Spine acc. to Matzen, Ulrich HS / de 16/4/92 derer / ematzen.pm.3] and others).

The second group consists of systems which can be characterized as semi-rigid. These instruments are characterized by the following:

(a) from a bar equipped at least at its ends with appropriately shaped clamping elements which is operatively applied from the concave or convex side of the deformity and the clamping elements are attached while maximally compensating for vertebral deformity in the vertebrae at the beginning and end of the deformity; to correct for deformity by acting with the long spine of the parallel spreader force on its concave side or the compressive forces on its convex side,

b) a coil spring provided with suitable clamping elements at the ends, which is operatively applied from the convex side of the deformity and the clamping elements are attached to the vertebrae at the beginning and end of the deformation while stressing the longitudinal axis spine of parallel compressive forces on its convex side,

(c) a combination of elements according to the two preceding points, which may also be interconnected, functionally correcting the spinal deformity by applying parallel compressive forces to its convex side while simultaneously applying parallel expansion forces to its concave side.

The instrumentation belonging to the group of semi-rigid systems suitably corrects the spinal deformities and significantly or completely limits the movement in the spinal deformity region only in the direction of the corrective forces. The spine never stabilizes in all three planes (external corset fixation is always necessary when applied), but limits its growth, as joints are surgically disrupted and spondylodesis induced. This group includes e.g. Allanov [Allan F.G., J. Bone Joint Surgeon, 37 / B, 1955, 92-96] and Kazmin's Distractor, Gruc Spiral Springs [Gruca A., Beitr. Orthop. u. Traumatol., 5, 1958, 1-11; Gruca A., J. Bone Joint Surg., 40 / A, 1958, 570-584], their modification according to Weis [Weiss M., Bentkowsky Z., Clin. Orthop., 1974, 103-109], Harrington distraction, compression system [Harrington P. R., J. Bone Joint Surg., 44 / A, 1962, 591-610; Harrington P.R., Orthop. Clin. of North Am., 3, 1972, 49-67] and others.

The third group can be characterized as telescopic systems, which are characterized by:

(a) a constant-length bar on which suitable clamping elements are attached such that the position of at least one element is adjustable in the direction of the long spine axis;

b) of two telescopic rods (the telescopic rod is designed as a rod inserted into the coaxial tube with one end) at both ends interconnected, with clamping elements situated mostly at the ends of the bars, the length of the bars and thus the position of at least one clamping element in the direction of the long spine axis.

Said instruments are operatively applied to the sides of the spinal deformity and, through their clamping elements, ensure the transmission of correction forces to the deformed vertebral vertebrae. In the instrumentation according to a), it is possible to change the position of the at least one clamping element at any time in the periodically repeating surgical interventions of the local range so as to align it with the growth of the spine.

The instrumentation according to b) is spontaneously modified in length in accordance with the growth of the spine. An essential advantage of these instrumentations is the minimization of the extent of irreversible changes on the spine and the use of only one and only once operatively applied instrumentation for the spine growth period. However, they still have the disadvantage characteristic of all the other solutions mentioned so far, i.e. substantial limitation of spinal mobility. Currently, this group includes Harrington's distraction instrumentation [Moe J. H., Orthop. Clin. of North Am., 3, 1972, 17-48] using a rack or screw that does not provide rotational stability and therefore external spinal fixation with a corset is required. The latest system is the Ulmer-Teleskop-Stab instrumentation used in neuromuscular scoliosis, which stabilizes the spine in all three planes (eliminating the need for corset stabilization), correcting deformity while telescoping following its longitudinal axis growth.

It is clear from the above that all known solutions of the device for correcting the deformation of the spine have two significant disadvantages, namely:

1) substantial restriction, resp. complete elimination of motility and spine growth at least in the area of its deformity,

2) the need for multiple surgical interventions when applied to a growing spine, which represents a significant burden on the patient.

It is an object of the present invention to provide medical practice with such instrumentation that suppresses or eliminates these drawbacks to the maximum extent possible.

SUMMARY OF THE INVENTION

The spine deformation correction device according to the invention consists of at least two segments which are fixed to the vertebral vertebra and interconnected with each other, the essence of the invention being that each segment consists of a segment body connected to at least one clamping element (e.g. in the form of a hook) , jaws, sleeves, screws, wire loops, etc.) by which the segment is fixed to at least one vertebra vertebra in the region of its deformity and at the same time comprises at least one spring tongue whose length is substantially greater than its other dimensions and through which it is a force bond associated with at least one additional segment fixed to at least one other vertebral vertebra. The line passing through the beginning and the end of the spring tongue has an angle of up to 45 ° with the vertical axis of the vertebra in the frontal plane as well as in the sagittal plane in the ventral and / or dorsal direction.

In the solution according to the invention, two basic alternatives for attaching the spring tongue are possible. In the first case, each end of the spring tongue is firmly attached (eg by being an integral part of the body of the segment, or fixed to it by welding, screw connection, etc.) on another segment, thereby creating a bridging between them to ensure transmission forces from one segment to another. In the second case, one end of the spring tongue is fixedly fixed to one segment and the other segment is provided with a recess in the form of a recess or an opening in the body of the other segment in which the other end of the spring tongue is received. The seating sleeve, when applying the device according to the invention, isolates the point of contact of the spring tongue with the segment from the surrounding tissues and thus prevents them from being damaged when the free end of the spring element is moved due to spine bending. The bearing sleeve is substantially in the form of a ring or part of a ring with a circular, elliptical or rectangular opening, respectively. a circular, elliptical or rectangular aperture formed in the body of the segment, wherein the transverse dimensions of the aperture are at least 0.01 mm larger than the corresponding dimensions of the free end of the elastic element.

From a production and application point of view, it is suitable that the segments are unified, i. if each segment comprises a resilient element attached thereto and at the same time an abutment sleeve. When applying the segments to the deformity of the spine, it is necessary that the forces applied by the segments to the individual vertebrae in the deformation region have a differentiated magnitude, i. that the spring tongues attached to the individual segments have differentiated mechanical properties. This is preferably achieved in that the individual spring tongues are made of a different material and / or have different transverse cross-sections with respect to their longitudinal axis, and / or differ in shape and / or are held in different positions on the individual segments, in terms of the location of their attachment to the segment as well as their inclination relative to the vertebral vertical axis.

In view of the unification required in the manufacture of the segments and the ease of their application to the spine, it is particularly advantageous for the segment body to be provided with a ball-shaped projection in which a threaded hole is formed at its apex and the spring tongue end is also formed into a hollow section. a sphere having an inner radius substantially equal to the radius of said projection, but a height of at least 0.01 mm, at which a through hole is formed at its apex. The segment also comprises a fixation pad having a ball-shaped recess having a diameter substantially equal to the outer radius of said end of the spring tongue, and at the apex of said recess a circular opening is formed, said spring tongue end concave on said projection and on its convex side said fuser pad removal is stored. The relative position of these elements is fixed by means of a screw having a diameter of at least 0.01 mm smaller than the diameter of the holes in the spring tongue and the fixing washer through which it is screwed and screwed in the thread located at the top of said projection on the body of the segment. An essential advantage of such a segment construction is that, with a minimal variety of flexible tongues and segments, the relative simplicity of their shape and manufacture, and the ease of assembly when applied to the vertebrae, respectively. By varying the rotation of the spring tongue, within a range of angles determined by the characteristic of the deformity and the particular design of the segment (particularly with respect to the ratio of the screw diameter and the hole size at the end of the spring tongue), a wide variety of force actions can be achieved.

In cases where it is necessary to create such a high force bond between the segments to correct significant spinal deformity, especially in a dorsal direction, that there is a real risk of damaging the vertebral vertebra on which they are attached, it is particularly advantageous if the segment is substantially as described, but with the exception that a through hole opening at its top is formed in said spherical projection on the body of the segment. A hollow bolt, which is screwed into the vertebra, preferably through a pedicle in the vertebral vertebra of the vertebra, passes through this opening and inside which a threaded hole is provided for attaching a screw fixing the relative position of the individual parts of the segment. With such a constructional solution, it is possible to significantly distribute the force load on the vertebra at the point of attachment of the segment and thus significantly reduce the possibility of its damage.

For the latter two alternatives of the segment construction, it is advantageous if it comprises a bearing sleeve in the form of one side of the open recess formed in the body of the segment, the bearing sleeve being covered from its open side by a fixing pad. On the one hand, complete stripping of the end of the tongue from the tissues in its vicinity is achieved and at the same time the application of the segments on the vertebral vertebrae is substantially simplified, since the second segment can be installed without the force linkage. by additionally inserting the end of the spring tongue into the bearing bush, its position in the bushing being secured by the fixing pad of the second segment simultaneously with the fixation of its own spring tongue.

If the spring tongue is fixed on only one segment and its free end is inserted in the seating sleeve of the next segment, there is a real danger that the loose end of the tongue may slip out of the seating sleeve due to the limited length of the backbone. damage to surrounding tissues associated with the need for further surgery. Said hazard is eliminated by the design of the spring tongue and the bearing sleeve according to the invention, in which the spring tongue comprises at its free end at least part of the circumference an extension and at the end of the bearing bush farther from the segment on which said spring tongue is fixed the length of the groove into which it snaps when the spine is bent excessively. The groove in the seating sleeve is preferably designed so that it allows not only a linear movement but also a rotary movement of the spring tongue in the seating sleeve within a given range.

From the point of view of applying the segment to the vertebrae of the vertebrae, it is advantageous if the segment comprises a clamping element in the form of a shaped clamp provided with a fixing screw at the ends of the arms which allows the ends of the shaped clamp arms to be pulled together. The aperture of the shaped clamp here corresponds to the shape of the vertebral vertebra to which the segment will be attached, preferably it has a cross-sectional shape of the vertebral arch at a location between the mandrel and the vertebra pedicle.

In addition to the advantages of the prior art, the backbone correction device of the present invention has a significant advantage over prior art solutions in that, due to the flexible interconnection of its segments, it allows the patient to bend the spine to the extent necessary for daily life, even during intense growth a spine that does not limit and at the same time the force bond between the segments is so strong that no brace is required. The presented solution is so structurally and applicationally flexible that it can be easily adapted to a particular type of spinal deformity and due to a limited number of necessary surgical interventions (usually one or two surgical interventions will suffice) represents minimal burden on the patient's organism. blood loss.

Overview of the figures in the drawing

For a better understanding of the invention, the solution is shown in the attached drawing, where:

Fig. 1 is a schematic view of three segments situated on three vertebra vertebrae; FIG. 2 is a view of two segments interconnected by one spring tongue fixedly fixed on both segments; FIG. 3 is a schematic view of three segments showing the vertebral vertebrae on which they are mounted, FIG. 4 is a view of a segment with a shaped clamp and a partial cross-section of the bearing sleeve, FIG. 5 is a cross-sectional view of the A-A segment of FIG. 4, FIG. 6 is a cross-sectional view of a spring tongue with a washer and a screw, FIG. 7 is a cross-sectional view of a segment fixed to the vertebra by means of a hollow screw.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Segments 1, 1 ' and 1 ' 1 are made of stainless steel according to ISO 5832/211, the segment 1 fixed on the vertebra 7 consisting of a segment body 2 and a clamping element 3 formed as a shaped clamp, the arms of which are tightened to each other by a clamping screw 6. 4, the other end of which is housed in the seating sleeve 5 'of another segment 1', which is designed as a through hole. Other segments 1 ', 1' are provided with the same clamping elements 3 ', 3' made as a shaped clamp, each of said segments '1' being designed to be mounted on one vertebrae 7 ', 7' spine. When the spinal deformation correction device of FIG. 1, the segment 1 is first fastened to the vertebral vertebrae 7 by means of its clamping element 3, the end sleeve 5 'of the segment 1' is slid onto the end of its spring tongue 4, which is adjusted by a suitable instrumentation to a position ensuring 'and is attached to the vertebra vertebra 7' by its clamping element 3 '. The third segment 1 "is fastened to the vertebra vertebrae 7" by means of its clamping element 3 "and then, by means of suitable instrumentation, is set to the position necessary to create the desired force action on the segment 1 ', in this position the spring tongue 4 'and its end is fixed to the segment 1' by a screw 8 '.

Example 2

Segments 1.1 ’as shown in FIG. 2 are made of stainless steel according to ISO 5832/211, the segment 1 comprising a clamping element 3 designed as a hook. In the body 2 of the segment 1, a spring tongue 4 is mounted and fixed by a screw 8, the other end of which is fixed by the screw 8 'in the seating sleeve 5' of another segment 1 ', which is designed as a through hole. A longitudinal opening is formed in the spring 4 at its end through which the screw 8 'passes and by means of which the distance of the two segments can be continuously adjusted as the spine grows. The second segment 1 'is provided with a clamping element 3 ’formed as a groove on the surface of the clamping element 3 do in which, during application of the segment to the spine, a wire loop is inserted to fix it to the respective vertebra. Each of said segments 1, 1 'is designed to be attached to only one vertebral vertebra.

Example 3

The spinal deformation correction device of FIG. 3 is made of titanium alloy Ti - 6A1 - 7Nb and consists of three segments 1, 1 ', 1', of which only the first segment 1 is attached to two vertebrae vertebrae 7, 7 'by a shaped clamp 3 and others are fixed in the same way on one vertebra. Two spring tongues 4.1, 4.2 are fastened to segment 1, of which the first tongue 4.1 has a constant rectangular cross-section in length, is made of stainless steel according to ISO 5832/1 and is fastened to segment 1 by means of a screw 8 passing through the bearing bush 5 and a seating bush 5.1 '', also formed as a rectangular recess in the third segment 1 ', in which a groove 17 is provided to prevent the tongue 4.1 from being disposed, provided with a protrusion 16 from the bushing 5.1' 'at the end. The second spring tongue 4.2 is an integral part of the segment 1, has a constant circular cross-section along its length and is fastened by the other end in the second seating sleeve 5.2 ”of the third segment 1”, which is designed as a circular bore.

Example 4

The segment of the spine correction device of FIG. 4 consists of a clamping element 3 formed as a shaped clamp and a body of the segment 2 on which a spherical-shaped projection 9 (see section AA in FIG. 5) with a threaded hole 10 is formed. A protruding end 11 of the spring tongue 4 with a through hole 12 (see FIG. 6) is mounted on the protrusion 9 and there is a fixing pad 13 provided with a semicircular recess 14 with a through hole 15 at its top, the relative position of said elements being fixed by means of a screw 8 extending through said holes 12, 15 and screwed into the threaded hole 10. The seating sleeve 5 is formed as a one-sided open recess in the body 2 of the segment, in which a groove 17 is formed on one side about half of its length. The housing 5 accommodates the free end of the spring tongue 4 'firmly attached to the previous segment. The end position of the spring tongue 4 'in the seating sleeve 5 is provided by a fixing washer 13 closing the open side of the housing 5. The spring tongue 4' is held in a position so that it presses against the segment body 2 under pressure and pushes it to a position to correct the spinal deformity.

Example 5

The segment of the spine correction device according to Example 4 distinguished by comprising (see Fig. 6) a spring tongue 4 attached to the body 2 of the segment which is not rectilinear but longitudinally shaped so that even with limited possibilities of changing its position with respect to the segment body 2 can, due to its curvature, achieve the necessary force action on the following vertebra.

Example 6

The segment of the spine correction device according to Example 5 is distinguished by the fact that a projection 9 has a through hole 16 (see Fig. 7) in which a hollow screw 8.1 is located. Said hollow screw 8.1 is threaded on its outer surface and a threaded bore 10 is formed therein, its end screwed in the set 7 being divided into at least two parts by longitudinal cuts. In the threaded bore 10 there is a fixing screw 8 which, when screwed into the threaded bore 10, squeezes the individual longitudinal portions of the hollow screw 8.1 and thus increases the gripping strength thereof in the set 7.

The examples of the spinal deformation correction device according to the invention given are merely illustrative of specific embodiments, which in no way limit the scope of the invention defined in the claims.

Industrial usability

Due to its structural design, the device according to the invention can be advantageously applied to all known expensive spinal deformities.

Claims (10)

PATENT CLAIMS A spine correction device comprising at least two segments which are fixed to the vertebral vertebra and interconnected, characterized in that each segment (1) consists of a body (2) provided with at least one clamping element (3) which is fixed to the at least one vertebral vertebra and the at least one spring tongue (4), by means of which it is coupled by force bonding to at least one other segment (l ') fixed to at least one other vertebra vertebra, an angle up to 45 ° in the frontal plane and an angle up to 45 ° in the sagittal plane in the ventral and / or dorsal direction. Device according to claim 1, characterized in that one end of the spring tongue (4) is rigidly connected to one segment (1) and the other end is rigidly connected to the other segment (1 '). Device according to claim 1, characterized in that one end of the spring tongue (4) is fixedly fixed to one segment (1) and the expensive segment (1 ') is provided with a recessing sleeve (5) in the form of a recess or hole in the body (2). ') a segment in which the second end of the spring tongue (4) is accommodated, the transverse dimensions of the opening being at least 0.01 mm larger than the corresponding dimensions of the end of the spring tongue (4). Device according to claim 3, characterized in that each segment (1, 1 ') comprises at least one spring tongue (4) and at least one bearing bush (5) at the same time. Device according to one of Claims 1 to 4, characterized in that in the segments (1) to be applied to different spinal deformities, the spring tongues (4) differ in their dimensions and / or the material from which they are made and / or a fixation point on the body (2) of the segment and / or shape, and / or angle that clamp with the vertical axis of the vertebra (7). Device according to one of Claims 3 to 5, characterized in that a spherical projection (9) is formed on the segment body (2), in which a threaded bore (10) is formed at the top thereof, (11) the spring tongue (4) is formed into a hollow sphere section with an inner radius substantially equal to the projection radius (9), but at a height of at least 0.01 mm, at which a through hole (12) is formed at its apex wherein the segment (1) comprises a fixation pad (13) with a spherical recess (14) having a diameter substantially equal to the outer radius of the end (11) of the spring tongue (4) and a through hole (15) is formed at the apex of the recess (14) ), wherein the end (11) of the spring tongue (4) is concave on the projection (9), its convex side accommodates a recess (14) of the fixing pad (13) and the relative position of these elements is fixed by a screw (8) a diameter of at least 0,01 m m smaller than the diameter of the holes (12, 15) through which it passes and is screwed into the threaded hole (10). Apparatus according to claim 6, characterized in that a through-hole (16) is formed at the top of the spherical-shaped projection (9) and a hollow bolt (8 ') is located inside the hole (10). threaded and screwed through the pedicle into the vertebral vertebrae body. Apparatus according to claim 6 or 7, characterized in that the segment (1) comprises an abutment sleeve (5) in the form of a one-side open recess formed in the segment body (2), which is covered by a fixing pad (13). Device according to one of claims 3 to 8, characterized in that the spring tongue (4) comprises at its free end at least a part of the circumference an extension (16) and a groove (17) formed at the end of the seating sleeve (5) of the second segment (4). 1 ') further from the first segment (1) on which the spring tongue (4) is fixed. Device according to one of Claims 1 to 9, characterized in that the clamping element (3) is a shaped clamp provided with a clamping screw (6) at the ends of the arms, the internal opening of the clamping element (3) having the cross-sectional shape of the between the mandrel and vertebra pedicle.