Spinal column deformity correction device

Abstract: The procedure includes: Fastening of a bar (1) by means of end pincers (2), joined to connectors (3). Union by means of metallic wires (4) of each intermediate pincer (2) with a wire-bar connector (5). Pulling of the wires (4) from their free ends. The device for putting the procedure into practice consists of: Pincers (2) attached to the vertebras with double claw (fixed and mobile). Pincer-bar connectors (3) with an orifice (15) through which the bar (1) passes and a cylindrical prolongation (13) for joining the pincer. Wire-bar connectors (5) passing through an orifice (21) with two paths and a curved joint (22) through which the wire passes. Wires (4) with an end butt (23) able to be pulled by its free end.

Description: The purpose to which the invention refers consists of a Spinal column malformation correction device. The malformations for the correction of which both the procedure and the device are applied consist of curvature of the longitudinal axis of the spine when this should be anatomically straight, with both (procedure and device) being apt for correcting any malformation, pathological or traumatic, whatever its origin. On the other hand, the claimed device admits slight variants that do not alter or impair its essentiality, thus constituting "a group of inventions interrelated in such a way that they integrate a unique general inventive concept". HISTORY Different attachment techniques of the attaching elements posterior to the vertebras are known, which make up the spinal column malformation correction systems by means of lateral displacement of the vertebras. The preferential fastening of said attaching elements is located on the vertebral laminas as these are the most resistant mooring places of the posterior area of the rachis and, furthermore, the less affected by the osteoporosis processes that weaken the bone structure. The failure of various types of instrumentation usually occurs either due to pull-out of the attaching elements or due to the excessive magnitude of the loads applied to the rachis. The known and most used attaching elements are the following: Transpedicular screws: The placing of the screws through the vertebral peduncles implies a high risk of neurological damage as the peduncle can break, damaging the nearby nervous roots or the spinal cord itself. On the other hand, the strength required to remove them is relatively little. Sublaminar wires: These do not permit the transmission of axial loads to the tying bars, thus causing sliding along them when compression, lateral inclination and flexion displacements are made. Due to the reduced contact surface between the wire and the bone they tend to cut the vertebral laminas. Claws: These give rise to a connection that is unable to resist flector and torsion moments as they allow turning movements, although they provide resistance to posterior removal and longitudinal traction-compression forces. US-A-4 269 178 discloses an apparatus useful for the treatment of scoliosis. This apparatus comprises two metallic rods which are placed on either side of the curvature of the spinal column. One of the rods acts as a distraction system, the other rod acts as a compression system. Each rod is provided with hooks which penetrate into the inter-articular space and act as anchoring devices. In the peak region of the scoliotic curvature, both rods may be connected by a transverse tensioning device to achieve a better correction of the curvature. DE-A-2 854 647 refers to a device for correcting scoliotic malformations. The device comprises a rotatable rod which is attached to the spinal column on the concave side of the curvature. The rod is provided with a wire which is fixed to a vertebra located in the peak region of the curvature. Upon rotation, the wire is wound around the rod, thus straightening the curvature. The wire is fixed to a vertebra by using a screw. The rotatable rod is affixed to the spinal column by means of wire brackets. DESCRIPTION OF THE INVENTION The purpose of the invention constituting the object of this Patent consists in overcoming the inconvenience characteristic of the known procedures and devices for spinal column malformation correction by means of lateral moving of the vertebras described above. It has been conceived and designed specifically for this priority purpose. The procedure is of the type used for application to longitudinal metallic bars that serve as a support when nearing to them the elements attached to the vertebras, thus obtaining their lateral displacement. It includes the following operations: Fastening of a longitudinal metallic bar on the concave side of the spinal column curvature by means of pincers attached to the laminar or pedicular zone of the vertebras and linked to lateral bar-pincer connectors located on top and beneath the deformation, near the ends of the bar. Union by means of independent metallic wires of each intermediate pincer with a wire-bar connector linked to the bar, retaining an end of each wire at the corresponding pincer by means of prisoner screws and passing the opposite end through the connector. Progressive traction of all the wires from their free ends that have passed through the connectors, by means of tighteners anchored on the wire-bar connectors, until obtaining approximation of the intermediate pincers and the vertebras to which they are attached to the longitudinal bar, thus completing correction of the curvature. Mounting of a second longitudinal bar on the convexity side of the curvature to bilaterally stabilize the spinal column, attaching this second bar to the vertebras by means of other pincers. Replacement of the wires by lateral pincer-bar connectors when this is possible due to the proximity of the pincer to the bar. The device for putting the described procedure into practice consists of the following elements: Pincers attached to the vertebras through their laminar or pedicular zone, formed by two curved claws with opposite concavities, one of which forms part of the body of the pincer and the other independent, with a cylindrical lateral prolongation which on passing tightly through the body of the pincer allows it to make axial or turning displacements to adapt the relative position of the two claws to the shape and sizes of the zone of the vertebra where it is fastened. There is a prisoner screw for immobilization of the movable claw in the suitable position, as well as another prisoner screw to retain insertion of the connecting prolongation of the pincer-bar connectors and tautening wire through-orifice for lateral displacement of the vertebras. Pincer-bar connectors that have an orifice or groove for tight housing of the bar with a prisoner screw for its immobilization in the suitable position and a lateral cylindrical prolongation for connection to the corresponding'pincer. Longitudinal metallic bar held on its ends by pincer-bar connectors. Wire-bar connectors formed by a polyhedral body with beveled edges, crossed by a groove or longitudinal orifice through which the bar passes and to which it is attached by means of a prisoner screw, and by an orifice with two paths (side inlet and upper outlet), joined by curved transition through which the wire passes and a prisoner screw to retain it. This layout facilitates surgical access to the free end of the wire so that it can be tautened. Braided metallic wires thanks to the progressive pulling of which by means of conventional tighteners the approximation stress of the vertebras to the bar is caused. For this purpose a low cylindrical butt is provided on the end projecting through the body of the pincer. BRIEF DESCRIPTION OF THE DRAWINGS To complete the description of the invention and facilitate the interpretation of its formal, structural and functional characteristics, attached are drawings in which the different aspects of a preferred performance of the device for putting into practice the spinal column malformation correction procedure constituting the object of this Patent. In said drawings: Figure 1 presents a longitudinal section of a pincer fastened to the vertebras. Figure 2 represents a perspective view of the union between the bar and pincer by means of a connector. Figure 3 represents a perspective view of the union of a wire-bar connector to the bar; figure 4 a transversal section of the same through a vertical plane that diametrically cuts the wire through-orifice; and figure 5 the active position of a wire-bar connector mechanically joining the bar and pincer by means of a wire. Figure 6 is a general perspective of the correcting device, showing the relative positions of the end pincers linked to the bar by means of pincer-bar connectors and of the intermediate pincers mechanically joined to the bar by means of respective wires through wire-bar cables. Figure 7 schematically represents the connection of the longitudinal to the column by means of end pincers and pincer-bar connectors. Figure 8 shows the application of the procedure by means of the device, with correction of the curvature already obtained through lateral displacement of the vertebras and their approximation to the bar, thanks to the pulling of the wires on the intermediate pincers. Figure 9 shows bilateral stabilization of the column with a second longitudinal bar. DESCRIPTION OF A PREFERRED PERFORMANCE In order to clearly show the nature and scope of the advantageous application of the Spinal column malformation correction device, constituting the object of the invention as described in claim 1, the following is a description of its application and structure, making reference to the drawings which, on representing a preferred performance of the device and its components for information purposes, must be considered in the widest sense and not limitative of the application and content of the claimed invention. The correction is of the type that uses, for its application, longitudinal metallic bars serving as a support for nearing the elements attached to the vertebras to them. It includes the following operations: Fastening of a longitudinal metallic bar (1) on the concave side of the spinal column curvature by means of pincers (2) attached to the laminar or pedicular zone of the vertebras and linked to lateral bar-pincer connectors (3) located on top and beneath the deformation, near the ends of the bar (1). Union by means of independent metallic wires (4) of each intermediate pincer (2) with a wire-bar connector (5) linked to the bar (1), retaining an end of each wire at the corresponding pincer by means of prisoner screws (6) and passing the opposite end through the connector (5). Progressive traction of all the wires (4) from their free ends that have passed through the connectors (5), by means of tighteners anchored on the wire-bar connectors, until obtaining approximation of the intermediate pincers (2) and the vertebras to which they are attached to the longitudinal bar, thus completing correction of the curvature. means of other pincers. Replacement of the wires (4) by lateral pincer-bar connectors (3) when this is possible due to the proximity of the pincer to the bar. The device for putting the described procedure into practice consists of the following elements: Pincers (2) attached to the vertebras, formed by two curved claws with opposite concavities, one of which (7) forms part of the body (8) of the pincer and the other (9) independent, with a cylindrical lateral prolongation (10) which on passing tightly through the body (8) of the pincer allows it to make axial or turning displacements to adapt the relative position of the two claws to the shape and sizes of the zone of the vertebra where it is fastened. There is a prisoner screw (11) for immobilization of the movable claw (9) in the suitable position, as well as another prisoner screw (12) to retain insertion of the connecting prolongation (13) of the pincer-bar connectors (3) and tautening wire (4) through-orifice (14) for lateral displacement of the vertebras. Lateral pincer-bar connectors (3) that have an orifice or groove (15) for tight housing of the bar with a prisoner screw (16) for its immobilization in the suitable position and a lateral cylindrical prolongation (13) for connection to the corresponding pincer (2). Wire-bar connectors (5) formed by a polyhedral body (18) with beveled edges, crossed by a groove or longitudinal orifice (19) through which the bar (1) passes and to which it is attached by means of a prisoner screw (20), and by an orifice (21) with two paths (side inlet and upper outlet), joined by curved transition (22) through which the wire (4) passes and a prisoner screw (17) to retain it. Braided metallic wires (4) the progressive pulling of which nears the pincers (2) and the vertebras to which these are attached to the bar (1). For this purpose a low cylindrical butt (23) is provided on the end projecting through the body (8) of the pincer (2).

Claims: Device for use in a procedure for the correction of spinal column malformation, comprising one or two longitudinal metallic bars and a plurality of anchoring means which are detachably connected to each of said bars and which can be attached to the vertebras, characterized in that it comprises pincers (2) serving as said anchoring means, wherein each of said pincers is formed by a pair of curved claws with opposite concavities, and wherein one claw (9) of said pair of claws is moveable and can be tightened against the other claw (7) which is fixed; pincer-bar connectors (3) suitable for connecting a first group of said pincers to said bar(s), wherein said pincer-bar connectors and said first group of pincers serve to fasten said bar(s) to the spinal column; wire-bar connectors (5) serving to connect a second group of pincers to said bar(s) by means of metallic wires (4) fixed to said pincers and passing through said connectors, thus allowing the application of traction forces on said wires and pincers for correcting the curvature of the spinal column. Device in accordance with claim 1, characterized in that said pincers are attachable to the laminar or pedicular zone of the vertebras. Device in accordance with claim 1 or 2, characterized in that said moveable claw (9) comprises a cylindrical lateral prolongation (10) passing tightly through the body (8) of the pincer, thus allowing this claw to make axial or turning movements to adapt the relative positions of the two claws to the shape and sizes of the vertebras. Device in accordance with claim 3, characterized in that said pincer comprises a locking screw (11) for immobilizing the movable claw in a suitable position. Device in accordance with any one of the preceding claims, characterized in that the body of said pincers is provided with a bore (14) through which wire (4) passes, and the end of wire (4) which projects through said bore of the body is provided with a cylindrical butt (23), and said wire is a braided metallic wire. Device in accordance with any one of claims 1 to 4, characterized in that the body of said pincers is provided with a bore (14) through which wire (4) passes, and a locking screw (6) for retaining the end of the wire in a fixed position. Device in accordance with any one of the preceding claims, characterized in that a bore is provided in the body of said pincer for inserting a connecting prolongation (13) which extends from one of said pincer-bar connectors, and a second locking screw (12) is provided in the body of the pincer for immobilizing the pincer in a suitable position on said prolongation. Device in accordance with any one of claims 1-6, characterized in that said pincer-bar connectors (3) are provided with an orifice or groove (15) suitable for receiving the bar (1), and with a locking screw (16) for immobilizing the pincer-bar connector in a suitable position on said bar (1). Device in accordance with claim 8, characterized in that said pincer-bar connectors are provided with a connecting prolongation (13) which passes through a bore provided in the body (8) of a pincer attached to said connecting elongation, and a second locking screw (12) is provided in the body of the pincer for immobilizing the pincer in a suitable position on said connecting elongation. Device in accordance with any one of the preceding claims, characterized in that said wire-bar connector comprises a longitudinal orifice or groove (19) formed in the body (18) of said connector, said orifice or grove being suitable for receiving the bar (1); a third locking screw (20) by which bar (1) passing through said orifice or groove can be fixed in a suitable position; a tube-like, curved channel (22) which is formed inside the body (18) of said connector and which serves to receive wire (4) passing through the inlet and outlet (21) openings of said channel; a locking screw (17) for retaining wire (4) in a fixed position. Device in accordance with any one of the preceding claims, characterized in that said wire-bar connector comprises a polyhedral body (18) with bevelled edges. Device in accordance with any one of the preceding claims, characterized in that each pincer-bar connector is connected to a pincer (2); a plurality of wire-bar connectors (5) attached to the intermediate portion of said bar which lies between said end portions, wherein each wire-bar connector is connected to a pincer by means of a wire or cable (4). Device in accordance with claim 12, characterized in that it is affixed to a spinal column which exhibits a curvature, such that said metallic bar (1) is fastened on the concave side of the curvature of the spinal column, the upper end portion of the bar being located on top of the curvature and the lower end portion of the bar being located underneath the curvature; at least one pincer-bar connector is attached, in use, to the upper end portion of said bar (1), each pincer-bar connector being connected to a pincer (2); at least one pincer-bar connector is attached, in use, to the lower end portion of said bar (1), each pincer-bar connector being connected to a pincer (2); a plurality of wire-bar connectors (5) is attached to the intermediate portion of said bar which lies between said end portions, wherein each wire-bar connector is connected to an intermediate pincer by means of a wire or cable (4) which passes through the connector; said pincers being able to be anchored to vertebras of the spinal column. Device in accordance with any one of the preceding claims, characterized in that it comprises a pair of longitudinal bars (1), each having a plurality of pincer-bar connectors and a plurality of wire-bar connectors attached thereto, wherein each of said connectors is connected to a pincer. Device in accordance with claim 14, characterized in that both bars (1) are joined together mechanically.

Inventors: ATIENZA VICENTA CARLOS M, FORRIOL PICO JOAQUIN, MAS GOMEZ FRANCESC J, MOLLA DOMENECH FERNANDO, PEREZ MILLAN LUIS, ATIENZA VICENTA, CARLOS M., FORRIOL PICO, JOAQUIN, MAS GOMEZ, FRANCESC J., MOLLA DOMENECH, FERNANDO, PEREZ MILLAN, LUIS, Atienza Vicenta, Carlos M., C/. Villa de Bilbao 40, Forriol Pico, Joaquin, C/. Villa de Bilbao, 40, Mas Gomez, Francesc J., C/. Villa de Bilbao, 40, Molla Domenech, Fernando, C/. Villa de Bilbao, 40, Perez Millan, Luis, C/. Villa de Bilbao, 40
Applicants: LAFITT SA, LAFITT, S.A.
Application year: 2000
Main classification: A61B17
IPC codes: A61B17