Patent Description:
In a normal condition of a spine, the spine is generally straight when viewed from the back, cervical vertebrae and lumbar vertebrae curve forward and thoracic vertebrae and sacral vertebrae curve backward when viewed from the side. In this way, the spine shows an approximately S-shaped appearance. Spinal deformity causing abnormality at the spine is a disease with the deformed spine, and includes scoliosis, kyphosis, and kyphoscoliosis, for example. Scoliosis is a disease in which the spine is twisted while being curved laterally. Kyphosis is a disease in which the angle of thoracic kyphosis becomes extremely large, or lumbar lordosis is lost to be deformed toward kyphosis. Kyphoscoliosis is a disease caused by a combination of scoliosis and kyphosis.

For treatment of such types of spinal deformity, spinal deformity correction and fusion surgery is widely conducted. The spinal deformity correction and fusion surgery is an operation for correcting a deformed spine to a normal state or a state close to the normal state and then fixing the corrected spine using a spinal deformity correction and fusion system (self-contained member, which is what is called an implant) described later. Posterior correction and fusion surgery or anterior correction and fusion surgery is employed for such operation. In particular, the posterior correction and fusion surgery is conducted as follows. For implementation of the posterior correction and fusion surgery, a patient is positioned on an operating table in a prone position. Then, an operative wound or a percutaneous surgical wound using minimally invasive technique is placed along the median line of the patient's back, and posterior elements of the spine are unfolded. Subsequently, a spinal deformity correction and fusion system described later (see patent literature <NUM>, for example) is mounted on the spine to three-dimensionally correct the spinal deformity. The spine is fixed in this state.

Generally, a system to be employed as the spinal deformity correction and fusion system includes: a plurality of screw members each to be screwed into a vertebral body through a pedicle of each vertebra of a spine; a hook member to be hooked on a pedicle, a vertebral arch, or a transverse process, for example, of each vertebra; rod members in a pair to be coupled to a top-opened groove of each screw and that of each hook member, extending along an axis direction of the spine, and arranged at an interval in a crosswise direction of a patient, etc..

For example, when a patient with scoliosis is subjected to posterior correction and fusion surgery conducted to correction and fusion of spinal deformity by mounting the above-described spinal deformity correction and fusion system on a spine, the screw member and the hook member are first fixed to each of a plurality of vertebrae to be corrected. Next, the rod member is engaged with the top-opened groove of the screw member and that of the hook member. At this time, the rod member extends linearly while the spine is deformed to make it quite difficult to engage the rod member with the top-opened groove of the screw member and that of hook member. In response to this, an operator uses a dedicated surgical instrument to give a curve to the rod member along the scoliosis deformity of the spine. Then, the curved rod is engaged with the top-opened groove of the screw member and that of the hook member fixed to each vertebra. Then, in order to prevent the rod member from coming off the top-opened groove of each screw member and that of each hook member, set screws are temporarily tightened in these top-opened grooves.

Next, the outer peripheral surface of the rod member is sandwiched with a dedicated surgical instrument corresponding to a pair of pliers and this surgical instrument is rotated about <NUM>° to rotate the rod member about <NUM>° about its axis. In this way, operation of correcting the scoliosis deformity including twisting of the spine is performed. Operation of correcting the scoliosis deformity of the spine is also performed by applying compressive load or tensile load between members such as a plurality of screw members arranged in the axis direction (cranio-caudal direction) of the spine and screw members arranged adjacent to each other in the axis direction of the spine, for example, using a dedicated surgical instrument. After implementation of such operation for the correction, the set screws are fully tightened to form firm coupling of the rod member with each screw member and each hook member, thereby correcting and fixing the spine.

According to the conventional correction and fusion method using the spinal deformity correction and fusion system, the rod member is engaged with the top-opened groove of each screw member and that of each hook member while being curved along the scoliosis deformity of the patient. As the spine is under the scoliosis deformity including twisting, however, it becomes quite difficult to engage the rod member, even in the curved state, with the top-opened groove of each screw member and that of the hook member. Additionally, as a range of the correction and fusion using the spinal deformity correction and fusion system becomes longer, it becomes more difficult to engage the rod member with the top-opened groove of each screw member and that of the hook member.

According to the conventional correction and fusion method using the spinal deformity correction and fusion system, operation of correcting the scoliosis deformity including twisting of the spine is performed by sandwiching the outer peripheral surface of the rod member firmly with a dedicated surgical instrument corresponding to a pair of pliers (such as a rod gripper) and by rotating the rod member about <NUM>°. If the rod member curved along the scoliosis deformity of the patient is rotated about <NUM>° about its axis, however, this curvature of the rod member is replaced with backward curvature and forward curvature of the patient. However, as this curvature of the rod member does not conform to the physiological backward curvature and forward curvature of the patient, another trouble might be caused.

Furthermore, according to the conventional correction and fusion method using the spinal deformity correction and fusion system, the outer peripheral surface of the rod member is sandwiched firmly with a dedicated surgical instrument corresponding to a pair of pliers and is rotated <NUM>°. This causes a risk of damage on the outer peripheral surface of the rod member at positions sandwiched with the surgical instrument corresponding to a pair of pliers. Additionally, as the set screws are temporarily tightened in the top-opened groove of each screw member and that of each hook member, rotating the rod member also causes a risk of damage on the outer peripheral surface of the rod member at positions of contact with the set screw. As a result, many of such damaged positions become causes for breakage of the rod member after indwelling inside a body.

The present invention has been made in view of the foregoing issues, and is intended to provide a corrective appliance capable of properly assisting in correction of spinal deformity by a spinal deformity correction and fusion system while limiting damage on a rod member when the spinal deformity is subjected to the correction and fusion by the spinal deformity correction and fusion system.

These methods do not form part of the claimed invention The embodiments and/or examples of the following description which are not covered by the claims, are provided for illustrative purpose only and are only intended to assist the reader in understanding the present invention. However, such embodiments and/or examples which are not covered by the claims do not form part of the present invention that is solely defined by the claims. The aspects of the invention described below exemplify the configuration of the present invention, and are described separately by items in order to facilitate the understanding of various configurations of the present invention.

When the spinal deformity is subjected to the correction and fusion by the spinal deformity correction and fusion system, the corrective appliance described in the item (<NUM>) is capable of assisting in the correction using the clamp member and the corrective member. Specifically, after the vertebra fixing tool is fixed to each vertebra, the clamp member is attached to each vertebra fixing tool and the corrective member is attached further to each clamp member. Next, the corrective member is operated to correct the spinal deformity properly though each clamp member and each vertebra fixing tool and the corrected state is retained. Next, the rod member is coupled to each vertebra fixing tool to fix a spine in the corrected state. Then, the corrective member and each clamp member are detached from each vertebra fixing tool and taken out of a body. During the correction and fusion of the spinal deformity in this way by the spinal deformity correction and fusion system, unlike in the conventional case, it is not necessary to engage the rod member of the spinal deformity correction and fusion system with each vertebra fixing tool fixed to each vertebra under scoliosis deformity including twisting, or to perform operation of giving a curve to the rod member of the spinal deformity correction and fusion system using a dedicated surgical instrument or operation of firmly sandwiching the rod member and rotating (turning) the rod member using a dedicated surgical instrument. As a result, it becomes possible to limit damage on the rod member as a self-contained member. Furthermore, using the corrective appliance allows the rod member of the spinal deformity correction and fusion system to be easily engaged with (coupled to) each vertebra fixing tool. As a result, correction of the spinal deformity becomes easier to facilitate implementation of a surgery itself, thereby contributing to reduction in a duration of the surgery.

The corrective appliance described in the item (<NUM>) is used effectively, particularly if the correction and fusion by the spinal deformity correction and fusion system covers a long range. Specifically, if the range of the correction and fusion by the spinal deformity correction and fusion system is long, the clamp member is attached selectively to the vertebra fixing tool fixed to each vertebra, the corrective member is attached to each clamp member, a deformed spine is corrected partially, and the corrected state is retained using these clamp member and corrective member. Then, the rod member is coupled to each vertebra fixing tool. By doing so, the spine can be fixed in the corrected state.

(<NUM>) The corrective appliance described in the item (<NUM>) is characterized in that the clamp member includes a groove, and the corrective member is an auxiliary rod member configured to be engaged with the groove of the clamp member.

In the corrective appliance described in the item (<NUM>), the auxiliary rod member can be given a curve along scoliosis deformity and can be engaged with the groove of each clamp member fixed to each vertebra, instead of the rod member of the spinal deformity correction and fusion system (self-contained member). The auxiliary rod member can be used for correcting spinal deformity through the clamp member and the vertebra fixing tool. Then, the correction using the corrective appliance is completed and the correction is retained. In this state, the rod member as the self-contained member is coupled to each vertebra fixing tool, thereby allowing retention of the corrected state of the spinal deformity by the spinal deformity correction and fusion system. As a result, it becomes possible to limit damage on the rod member as the self-contained member, thereby reducing the occurrence of breakage of the rod member easily after the rod member indwells in a body.

(<NUM>) The corrective appliance described in the item (<NUM>) or (<NUM>) is characterized in that the clamp member includes supporting pieces in a pair movable closer to and farther from each other to support a head of the vertebra fixing tool in such a manner as to sandwich the head.

In the corrective appliance described in the item (<NUM>), the clamp member can be attached to support the head of the vertebra fixing tool in such a manner as to sandwich the head using the supporting pieces in a pair of the clamp member. Furthermore, a top-opened groove provided at the top face of the head of the vertebra fixing tool and used for engagement with the rod member can be exposed to the outside. As a result, after correction of spinal deformity and retention of the corrected state using the clamp member and the corrective member, the rod member can be engaged easily with the top-opened groove of each vertebra fixing tool. Furthermore, the vertebra fixing tool can be supported firmly from opposite lateral sides of the head using the supporting pieces in a pair of the clamp member. Thus, force of the correction applied from the clamp member can be transmitted properly to a vertebra through the vertebra fixing tool, making it possible to correct the spinal deformity properly.

(<NUM>) The corrective appliance described in the item (<NUM>) or (<NUM>) is characterized in that the clamp member includes a ring-like member to support a head of the vertebra fixing tool in such a manner as to surround an outer periphery of the head.

In the corrective appliance described in the item (<NUM>), the clamp member can be attached to support the head of the vertebra fixing tool in such a manner as to surround the outer periphery of the head using the ring-like member of the clamp member. This allows the head entirely of the vertebra fixing tool to be supported firmly using the ring-like member of the clamp member. Thus, force of the correction applied from the clamp member can be transmitted properly to a vertebra through the vertebra fixing tool, making it possible to correct spinal deformity properly.

(<NUM>) The corrective appliance described in any one of the items (<NUM>) to (<NUM>) is characterized in that the clamp member includes a fixing tool for fixing the auxiliary rod member to the groove of the clamp member.

In the corrective appliance described in the item (<NUM>), by operating the auxiliary rod member while the auxiliary rod member is temporarily tightened to the groove of each clamp member using the fixing tool, it becomes possible to correct spinal deformity easily through each clamp member. The auxiliary rod member is fixed firmly to the groove of each clamp member using the fixing tool. By doing so, the spinal deformity can be retained in the corrected state using the clamp member and the auxiliary rod member.

(<NUM>) The corrective appliance described in the item (<NUM>) or (<NUM>) is characterized in that the clamp member includes stopper pawl sections in a pair for sandwiching the head of the vertebra fixing tool.

In the corrective appliance described in the item (<NUM>), the stopper pawl sections in a pair can be used for fixing the clamp member to the vertebra fixing tool firmly. As a result, force of the correction applied from the clamp member can be transmitted properly to a vertebra through the vertebra fixing tool, making it possible to correct spinal deformity properly.

(<NUM>) The corrective appliance described in any one of the items (<NUM>) to (<NUM>) is characterized in that the corrective appliance is configured as a surgical instrument detachable from the vertebra fixing tool to be taken out of a body while the spinal deformity is corrected and fixed by the spinal deformity correction and fusion system.

As the corrective appliance described in the item (<NUM>) functions as a surgical instrument, it is not required to be made of a material having excellent biocompatibility such as titanium alloy or cobalt-chromium alloy. This imposes no limitation on a material to be used, leading to cost reduction.

(<NUM>) The corrective appliance described in any one of the items (<NUM>) to (<NUM>) is characterized in that the auxiliary rod member has an outer diameter same as that of the rod member.

The corrective appliance described in the item (<NUM>) can entirely be given a compact configuration.

(<NUM>) The corrective appliance described in any one of the items (<NUM>) to (<NUM>) is characterized in that the head of the vertebra fixing tool is provided with concaved sections for supporting tips of the stopper pawl sections.

In the corrective appliance described in the item (<NUM>), the stopper pawl sections of the clamp member are engaged with the concaved sections at the vertebra fixing tool. This makes it possible to minimize backlash of the clamp member relative to the vertebra fixing tool occurring during attachment of the clamp member to the vertebra fixing tool.

The corrective appliance according to the present invention is capable of properly assisting in correction of spinal deformity by a spinal deformity correction and fusion system while limiting damage on a rod member when the spinal deformity is subjected to correction and fusion by the spinal deformity correction and fusion system.

Embodiments for carrying out the present invention will be described below in detail on the basis of <FIG>.

A corrective appliance 1A according to a first embodiment of the present invention will be described first in detail on the basis of <FIG>.

The corrective appliance 1A according to the first embodiment of the present invention is to assist in correction and fusion when spinal deformity is subjected to the correction and fusion by a spinal deformity correction and fusion system <NUM> (see Fig. <NUM>(f)). The spinal deformity correction and fusion system <NUM> briefly includes: a plurality of screw members <NUM> (see <FIG> and <FIG>) each to be screwed into a vertebral body through a pedicle of each vertebra of a spine; a plurality of hook members <NUM> (see <FIG>) each to be hooked on a pedicle, a vertebral arch, or a transverse process, for example, of each vertebra; and a rod member <NUM> (see <FIG>) to be coupled to a groove <NUM> of each screw member <NUM> and to a groove <NUM> of each hook member <NUM> and extending along an axis direction of a spine. These screw members <NUM> and hook members <NUM> correspond to a vertebra fixing tool. The spinal deformity correction and fusion system <NUM> further includes another constituting member such as a connector member (not shown in the drawings) provided to bridge the rod members <NUM>, <NUM> in a pair. A plurality of the screw members <NUM> and the rod members <NUM>, <NUM> in a pair of the spinal deformity correction and fusion system <NUM> are shown in Fig. <NUM>(f).

The screw member <NUM>, the hook member <NUM>, and the rod member <NUM> are made of a material of excellent biocompatibility such as titanium alloy. As shown in <FIG>, the rod member <NUM> is formed into a circular shape in a section. The length of the rod member <NUM> is set appropriately in response to a degree of spinal deformity of a patient. As shown in <FIG> and <FIG>, the screw member <NUM> is to be screwed into a vertebral body through a pedicle of each vertebra from the back of a spine. The screw member <NUM> is generally called a pedicle screw. The screw member <NUM> includes a rod receiving section <NUM> (head) with a groove <NUM> to receive the rod member <NUM>, and a screw portion <NUM> coupled to the rod receiving section <NUM> and to be screwed into a vertebral body through a pedicle of a vertebra.

The rod receiving section <NUM> is formed into a block-like shape in a plan view with planar portions <NUM>, <NUM> in a pair and arc-like portions <NUM>, <NUM> in a pair. The rod receiving section <NUM> is provided with the U-shape groove <NUM> opened on the opposite side of the screw portion <NUM> and extending in an axis direction of the rod member <NUM>. The groove <NUM> is formed in such a manner as to penetrate the planar portions <NUM>, <NUM> in a pair. The groove <NUM> is configured to receive the rod member <NUM>. The rod receiving section <NUM> has walls with inner wall surfaces facing each other across the groove <NUM> at which corresponding female threads <NUM>, <NUM> are formed. A set screw <NUM> is screwed into the female threads <NUM>, <NUM>. The planar portions <NUM>, <NUM> of the rod receiving section <NUM> are provided with concaved sections <NUM>, <NUM> in a pair formed at positions close to the respective tops of the planar portions <NUM>, <NUM>. The arc-like portions <NUM>, <NUM> of the rod receiving section <NUM> have outer peripheral surfaces where engagement grooves <NUM>, <NUM> extending in a peripheral direction are formed at positions close to the respective tops of the arc-like portions <NUM>, <NUM>. The screw portion <NUM> is coupled to the rod receiving section <NUM> in such a manner as to be swingable relative to the rod receiving section <NUM> in a direction in which the groove <NUM> extends. A range of the swinging motion of the screw portion <NUM> relative to the rod receiving section <NUM> is within <NUM>° from the center to each side (a total swinging range of about <NUM>°).

As shown in <FIG>, the hook member <NUM> is to be engaged with a vertebra by being hooked on a pedicle, a vertebral arch, or a transverse process, for example, of the vertebra from the back of a spine. The hook member <NUM> includes a rod receiving section <NUM> (head) with a groove <NUM> to receive the rod member <NUM>, and a hook portion <NUM> integrally connected to the rod receiving section <NUM>. The rod receiving section <NUM> is formed into a block-like shape in a plan view with planar portions <NUM>, <NUM> in a pair and arc-like portions <NUM>, <NUM> in a pair. The rod receiving section <NUM> is provided with the U-shape groove <NUM> opened on the opposite side of the hook portion <NUM> and extending in the axis direction of the rod member <NUM>. The groove <NUM> is formed in such a manner as to penetrate the planar portions <NUM>, <NUM> in a pair. The U-shape groove <NUM> is configured to receive the rod member <NUM>.

The rod receiving section <NUM> has walls with inner wall surfaces facing each other across the groove <NUM> at which corresponding female threads <NUM>, <NUM> are formed. A set screw <NUM> is screwed into the female threads <NUM>, <NUM>. The planar portions <NUM> of the rod receiving section <NUM> are provided with concaved sections <NUM>, <NUM> in a pair formed at positions close to the respective tops of the planar portions <NUM>. The arc-like portions <NUM>, <NUM> of the rod receiving section <NUM> have outer peripheral surfaces where engagement grooves <NUM>, <NUM> extending in a peripheral direction are formed at positions close to the respective tops of the arc-like portions <NUM>, <NUM>. In some cases, the hook member <NUM> includes a sandwiching part <NUM> arranged in such a manner as to face the hook portion <NUM> and to be movable in an axis direction. The sandwiching part <NUM> and the hook portion <NUM> can be used for firmly sandwiching a transverse process, etc..

A corrective appliance 1A according to the first embodiment of the present invention will be described next in detail on the basis of <FIG> and <FIG>. For the convenience of description, the following explanation is given on the assumption that, in <FIG> and <FIG>, the screw portion <NUM> of the screw member <NUM> shown in <FIG> is on a lower side and the rod receiving section <NUM> of the screw member <NUM> is on an upper side (on the opposite side of the screw portion <NUM>). The corrective appliance 1A according to the first embodiment of the present invention functions as a surgical instrument to be taken out of a body after spinal deformity is subjected to correction and fusion by the spinal deformity correction and fusion system <NUM> (see <FIG>). As shown in <FIG>, the corrective appliance 1A according to the first embodiment includes a clamp member 50A to be attached detachably to the rod receiving section <NUM> (head) of the screw member <NUM> and to be arranged close to the rod receiving section <NUM> of the screw member <NUM>, and an auxiliary rod member <NUM> as a corrective member to be attached detachably to the clamp member 50A and to be used for correcting spinal deformity.

As shown in <FIG>, in the present embodiment, the clamp member 50A of the corrective appliance 1A according to the first embodiment is attached to the rod receiving section <NUM> of the screw member <NUM>. The clamp member 50A is also attachable to and detachable from the rod receiving section <NUM> of the hook member <NUM> shown in <FIG>. The auxiliary rod member <NUM> is formed into a circular shape in a section. The auxiliary rod member <NUM> has an outer diameter substantially the same as that of the rod member <NUM> of the spinal deformity correction and fusion system <NUM>.

As shown in <FIG> and <FIG>, the clamp member 50A used in the corrective appliance 1A according to the first embodiment includes: a screw support <NUM> with supporting pieces <NUM>, <NUM> in a pair spaced apart from each other to support the rod receiving section <NUM> of the screw member <NUM>; a rod receiving section <NUM> with a U-shape groove <NUM> with an opened upper surface; a first gear <NUM> arranged in the rod receiving section <NUM>, a second gear <NUM> in meshing engagement with the first gear <NUM> extending from the interior of the screw support <NUM> to the interior of the rod receiving section <NUM>; and a rotary member <NUM> in meshing engagement with the second gear <NUM> and rotatably supported in such a manner as to bridge respective tips of the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM>. The supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> and the rotary member <NUM> correspond to a ring-like member.

The screw support <NUM> and the rod receiving section <NUM> are each composed of a single part. As understood from <FIG>, the screw support <NUM> and the rod receiving section <NUM> are connected integrally to each other in such a manner as to overlap each other partially, and are arranged side by side in a top-bottom direction in a plan view. The rod receiving section <NUM> has the U-shape groove <NUM> with the opened upper surface. The groove <NUM> is formed in a direction in which the rod member <NUM> extends. One of walls defined across the groove <NUM> of the rod receiving section <NUM> is formed into an arc-like wall <NUM> having an arc-like outer peripheral surface. The other of the walls defined across the groove <NUM> is formed into a block-like wall <NUM> having a shape like a block as a whole. A surface of the arc-like wall <NUM> and that of the block-like wall <NUM> facing each other are provided with corresponding female threads <NUM>, <NUM>. A set screw <NUM> (see <FIG>) is screwed into the female threads <NUM>, <NUM>. The set screw <NUM> corresponds to a fixing tool.

While not shown in the drawings, the bottom of the groove <NUM> of the rod receiving section <NUM> is provided with a circular concaved section opened at the bottom, and a through hole formed concentrically with the bottom of the circular concaved section. The first gear <NUM> (see <FIG>) is rotatably supported in the circular concaved section. As understood from <FIG>, a polygonal hole <NUM> penetrating the first gear <NUM> is formed at the center of the first gear <NUM> in a radial direction. The first gear <NUM> can be rotated by fitting a dedicated surgical instrument in the polygonal hole <NUM> and operating the fitted surgical instrument. A C-ring <NUM> is arranged on the first gear <NUM>. The C-ring <NUM> projects slightly from the bottom surface of the groove <NUM> of the rod receiving section <NUM>.

The block-like wall <NUM> is composed of a block body <NUM> and a supporting wall <NUM> projecting upward from the block body <NUM>. The above-described female threads <NUM> are formed in a range from the supporting wall <NUM> to the block body <NUM>. As understood from <FIG>, a surface of the block body <NUM> close to the screw support <NUM> is provided with a supporting cavity <NUM> for supporting one of the arc-like portions <NUM> of the rod receiving section <NUM> of the screw member <NUM> (see <FIG>). The supporting cavity <NUM> has a bottom surface where an engagement convex <NUM> is formed that is to be engaged with the engagement groove <NUM> (see <FIG>) provided at the outer peripheral surface of the arc-like portion <NUM> of the rod receiving section <NUM> of the screw member <NUM>. Poles <NUM>, <NUM> in a pair are formed across the supporting cavity <NUM> in such a manner as to extend in a direction in which the groove <NUM> extends, and the poles <NUM> are provided with female screw holes (not shown in the drawings) with opened upper surfaces. A fixing screw member <NUM> described later is threadedly engaged with each of the female screw holes. The supporting wall <NUM> having a substantially trapezoidal shape in a plan view is provided between the female screw holes of the block body <NUM> in such a manner as to project upward from the block body <NUM>.

A tiny gap <NUM> (see <FIG>) is provided between the block body <NUM> and the supporting wall <NUM> and close to the screw support <NUM>. A plate-like stopper member <NUM> is arranged in the gap <NUM>. The stopper member <NUM> is fixed in the gap <NUM> using two screw members <NUM>, <NUM>. The stopper member <NUM> is formed into a shape elongated in the direction in which the groove <NUM> extends in a plan view. The stopper member <NUM> has opposite ends as viewed in its lengthwise direction where concaved stoppers <NUM>, <NUM> are provided each arranged in such a manner as to block a tiny area around the female screw hole of the block body <NUM>. By doing so, even if the fixing screw member <NUM> described later is rotated excessively in a direction of being pulled out, male threads <NUM> of the fixing screw member <NUM> interfere with the concaved stopper <NUM> of the stopper member <NUM>, thereby preventing the fixing screw member <NUM> from coming off the corresponding female screw hole of the block body <NUM>.

As shown in <FIG> and <FIG>, the poles <NUM>, <NUM> of the block body <NUM> are provided with corresponding supporting spaces <NUM>, <NUM> rectangular in sections extending upward diagonally from outside toward the supporting cavity <NUM> in such a manner as to intersect the corresponding female screw holes and to penetrate the corresponding poles <NUM>, <NUM>. The supporting space <NUM> is formed in such a manner as to open the pole <NUM> on a side close to the screw support <NUM>. By referring further to <FIG>, a stopper pawl section <NUM> is supported in each of the supporting spaces <NUM> in such a manner as to be movable back and forth. The stopper pawl section <NUM> has a plate-like shape and is formed into a substantially rectangular shape in a plan view. The stopper pawl section <NUM> is provided with a long hole <NUM> extending in a lengthwise direction in such a manner as to penetrate the stopper pawl section <NUM>. The fixing screw member <NUM> described latter is passed through the long hole <NUM>. The stopper pawl section <NUM> has a tip where a pawl <NUM> is formed at an end thereof as viewed in a width direction in such a manner as to project in a lengthwise direction. The stopper pawl section <NUM> is configured to allow the pawl <NUM> at the tip of the stopper pawl section <NUM> to go into and out of the supporting cavity <NUM> of the block body <NUM>, as will be described later.

As shown in <FIG>, the fixing screw member <NUM> is composed of a hexagonal hole head <NUM>, and a shaft <NUM> with male threads <NUM>. The shaft <NUM> is composed of a small-diameter shaft section <NUM>, the male threads <NUM>, a large-diameter shaft section <NUM>, a tapered shaft section <NUM>, and a minimum-diameter shaft section <NUM> arranged in this order as viewed from the head <NUM> toward a tip. The small-diameter shaft section <NUM> has an outer diameter less than the outer diameter of the male threads <NUM>. The large-diameter shaft section <NUM> has an outer diameter less than the outer diameter of the male threads <NUM> and greater than the outer diameter of the small-diameter shaft section <NUM>. The tapered shaft section <NUM> is formed in such a manner that the outer diameter thereof is reduced gradually from the large-diameter shaft section <NUM> toward the minimum-diameter shaft section <NUM>.

As shown in <FIG>, the male threads <NUM> of the fixing screw member <NUM> are screwed into the female screw hole of the pole <NUM> of the block body <NUM> and the tapered shaft section <NUM> of the fixing screw member <NUM> is passed through the interior of the long hole <NUM> of the stopper pawl section <NUM> arranged in the supporting space <NUM> of each pole <NUM>. As the fixing screw member <NUM> is screwed in and is moved in the axis direction, the fixing screw member <NUM> is moved while the tapered shaft section <NUM> of the fixing screw member <NUM> is in contact with the inner wall surface of the long hole <NUM> of the stopper pawl section <NUM>. This allows the stopper pawl section <NUM> to go into and out of the supporting cavity <NUM> of the block body <NUM>.

As understood from <FIG>, the screw support <NUM> includes: a gear housing <NUM> connected to the rod receiving section <NUM> in such a manner as to overlap the rod receiving section <NUM> in the top-bottom direction, and the supporting pieces <NUM>, <NUM> in a pair provided integrally with the gear housing <NUM> and extending like branches from the gear housing <NUM>, and each provided integrally with and extending from a lower end portion of each of the poles <NUM>, <NUM> of the block body <NUM> of the rod receiving section <NUM>. The gear housing <NUM> has an opened lower section and the second gear <NUM> (see <FIG>) is housed in the gear housing <NUM>. Each of the supporting pieces <NUM>, <NUM> in a pair is provided with a housing cavity (not shown in the drawings) having an opened lower section. The rotary member <NUM> is arranged in the housing cavities in the supporting pieces <NUM>, <NUM> in a pair in such a manner as to cross the gear housing <NUM>. A substantially C-shaped cover member <NUM> is arranged at the screw support <NUM> in such a manner as to cover the second gear <NUM> in the gear housing <NUM> and to cover the rotary member <NUM> in the supporting pieces <NUM>, <NUM> in a pair from below.

By referring to <FIG>, the cover member <NUM> is provided with a projection <NUM> projecting outward in a radial direction toward the opposite side of the opened part thereof in the radial direction. The second gear <NUM> is supported rotatably on a support pin <NUM> standing from the projection <NUM>. The second gear <NUM> is arranged to cover an area from the gear housing <NUM> of the screw support <NUM> to a position adjacent to the first gear <NUM> in the bottom of the rod receiving section <NUM>, and is in meshing engagement with the first gear <NUM>. The second gear <NUM> is also in meshing engagement with a gear <NUM> of the rotary member <NUM>. A distance between the supporting pieces <NUM>, <NUM> in a pair is set to a distance that allows the planar portions <NUM>, <NUM> in a pair at the rod receiving section <NUM> of the screw member <NUM> to come into abutting contact with the supporting pieces <NUM>, <NUM> in a pair and to be fitted therebetween.

The rotary member <NUM> is formed into a C-shape. The rotary member <NUM> extends in the housing cavities in the supporting pieces <NUM>, <NUM> in a pair in such a manner as to cross the gear housing <NUM>, and is rotatably supported in such a manner as to bridge the tips of the supporting pieces <NUM>, <NUM> in a pair. The rotary member <NUM> has an outer peripheral surface where the gear <NUM> is formed. The gear <NUM> is in meshing engagement with the second gear <NUM>. The inner diameter of the rotary member <NUM> is substantially equal to an outer diameter defined by the arc-like portions <NUM>, <NUM> in a pair of the rod receiving section <NUM> of the screw member <NUM> (see <FIG>). Rotating the first gear <NUM> using a dedicated surgical instrument allows the second gear <NUM> and the rotary member <NUM> to rotate. The resultant rotation of the rotary member <NUM> makes it possible to open and close the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> relative to each other.

By referring to <FIG> and <FIG>, for attachment of the clamp member 50A to the rod receiving section <NUM> of the screw member <NUM>, a dedicated surgical instrument (not shown in the drawings) is fitted in the polygonal hole <NUM> of the first gear <NUM> arranged in the bottom of the groove <NUM> of the rod receiving section <NUM> and is then rotated to one direction, thereby rotating the first gear <NUM>, the second gear <NUM>, and the rotary member <NUM> to open the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> relative to each other. Next, while one of the arc-like portions <NUM> of the rod receiving section <NUM> of the screw member <NUM> is located in the supporting cavity <NUM> provided at the block body <NUM> of the block-like wall <NUM> at the rod receiving section <NUM> of the clamp member 50A, the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> of the clamp member 50A are brought into abutting contact with the planar portions <NUM>, <NUM> in a pair of the rod receiving section <NUM> of the screw member <NUM> at positions below the groove <NUM>. Locating the one arc-like portion <NUM> of the rod receiving section <NUM> of the screw member <NUM> in the supporting cavity <NUM> at the rod receiving section <NUM> of the clamp member 50A engages the engagement groove <NUM> (see <FIG>) provided at the outer peripheral surface of the one arc-like portion <NUM> of the rod receiving section <NUM> of the screw member <NUM> with the engagement convex <NUM> provided at the supporting cavity <NUM> of the rod receiving section <NUM> of the clamp member 50A (see <FIG>). By doing so, the movement of the clamp member 50A in the top-bottom direction relative to the screw member <NUM> is regulated.

Next, the dedicated surgical instrument (not shown in the drawings) is fitted again in the polygonal hole <NUM> of the first gear <NUM> arranged in the bottom of the groove <NUM> of the rod receiving section <NUM> and is then rotated to the opposite direction, thereby rotating the first gear <NUM>, the second gear <NUM>, and the rotary member <NUM> to close the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> relative to each other using the rotary member <NUM>. As a result, the inner peripheral surface of the rotary member <NUM> is brought into abutting contact with the outer peripheral surface of the other arc-like portion <NUM> at the rod receiving section <NUM> of the screw member <NUM>. By doing so, while the rod receiving section <NUM> of the screw member <NUM> is held using the rotary member <NUM>, the groove <NUM> of the screw member <NUM> (rod receiving section <NUM>) is exposed to the outside.

Next, a dedicated surgical instrument (not shown in the drawings) is fitted in the hexagonal hole head <NUM> of each fixing screw member <NUM> and the surgical instrument is rotated to one direction. By doing so, each fixing screw member <NUM> is screwed in to cause each fixing screw member <NUM> to move forward in the axis direction. At this time, each fixing screw member <NUM> moves forward while the tapered shaft section <NUM> of each fixing screw member <NUM> contacts the inner wall surface of the long hole <NUM> of each stopper pawl section <NUM>, thereby causing each stopper pawl section <NUM> to move forward toward the interior of the supporting cavity <NUM> of the block body <NUM>. As a result, the pawl <NUM> of each stopper pawl section <NUM> presses the concaved section <NUM> at each planar portion <NUM> of the rod receiving section <NUM> of the screw member <NUM>. By doing so, the rod receiving section <NUM> of the screw member <NUM> is sandwiched and fixed firmly from the sides of the planar portions <NUM>, <NUM> in a pair with the stopper pawl sections <NUM>, <NUM> in a pair. In this way, by attaching the clamp member 50A to the rod receiving section <NUM> of the screw member <NUM>, the clamp member 50A is located close to the rod receiving section <NUM> of the screw member <NUM>.

For detaching the clamp member 50A from the rod receiving section <NUM> of the screw member <NUM>, like in the case of attaching the clamp member 50A, a dedicated surgical instrument (not shown in the drawings) is fitted in the hexagonal hole head <NUM> of each fixing screw member <NUM> and the surgical instrument is rotated to the opposite direction, thereby causing each fixing screw member <NUM> to move backward in the axis direction. This causes the tapered shaft section <NUM> of each fixing screw member <NUM> to move backward to cause each stopper pawl section <NUM> to move slidably under its own weight inside the supporting space <NUM>. As a result, the pawl <NUM> of each stopper pawl section <NUM> is separated from the concaved section <NUM> at each planar portion <NUM> of the rod receiving section <NUM> of the screw member <NUM>, thereby releasing the rod receiving section <NUM> of the screw member <NUM> from the sandwiching action exerted by each stopper pawl section <NUM>.

Furthermore, a dedicated surgical instrument (not shown in the drawings) is fitted in the polygonal hole <NUM> of the first gear <NUM> arranged in the bottom of the groove <NUM> of the rod receiving section <NUM> and is rotated to one direction, thereby rotating the first gear <NUM>, the second gear <NUM>, and the rotary member <NUM> to open the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> relative to each other. In this state, the clamp member 50A becomes detachable from the rod receiving section <NUM> of the screw member <NUM>.

The following describes a method (not claimed) of assisting in correction and fusion using the corrective appliance 1A according to the first embodiment when spinal deformity is subjected to the correction and fusion by the spinal deformity correction and fusion system <NUM> on the basis of <FIG> and <FIG> and by also referring to <FIG> and <FIG>, if appropriate. While the spinal deformity correction and fusion system <NUM> in <FIG> and <FIG> simply performs correction and fusion of the spinal deformity by using only a plurality of the screw members <NUM> and the rod members <NUM> in a pair, this is intended to facilitate understanding of the method of assisting in the correction and fusion using the corrective appliance 1A according to the first embodiment. In some actual cases, a member such as the hook member <NUM> or a connector member (not shown in the drawings) is used as well as the screw member <NUM>, or another rod member is used in addition to the rod members <NUM>, <NUM> in a pair, if necessary.

As shown in <FIG>, in response to spinal deformity such as scoliosis, the screw member <NUM> is first screwed into a vertebral body through a pedicle of each of vertebrae (ten vertebrae in the drawing, for example) in a range of correction and fusion of a spine from the back of the spine. Next, in response to a case such as a single curve like the one shown in <FIG>, for example, the clamp member 50A is attached to the rod receiving section <NUM> of the screw member <NUM> screwed into each of vertebrae that may be five vertebrae within a range from the apex to the vicinity of the apex of the curve, for example. In this method (not claimed) the clamp member 50A is attached in such a manner that the rod receiving section <NUM> of this clamp member 50A is arranged external to the rod receiving section <NUM> of the screw member <NUM> as viewed in a crosswise direction of a patient. The explanation of the method of attaching the clamp member 50A to the rod receiving section <NUM> of the screw member <NUM> is omitted here as it has already been given above.

Next, one auxiliary rod member <NUM> is prepared and the auxiliary rod member <NUM> is curved using a dedicated surgical instrument (not shown in the drawings) along a curve of the scoliosis of the spine. Then, as shown in <FIG>, the auxiliary rod member <NUM> is engaged with the groove <NUM> of the rod receiving section <NUM> of each clamp member 50A. Next, the set screw <NUM> is screwed into the female threads <NUM>, <NUM> of the rod receiving section <NUM> of each clamp member 50A using a dedicated surgical instrument (not shown in the drawings) to temporarily tighten the auxiliary rod member <NUM>. At this time, when the auxiliary rod member <NUM> is pressed with the set screw <NUM> against the bottom surface of the groove <NUM> of the rod receiving section <NUM> of each clamp member 50A, the C-ring <NUM> on the first gear <NUM> presses the first gear <NUM> against the bottom of the circular concaved section of the rod receiving section <NUM>. By doing so, the rotation of the first gear <NUM> is regulated, so that the rod receiving section <NUM> (head) of the screw member <NUM> is continuously held using the rotary member <NUM>.

Next, in the state of <FIG>, operation is performed using a dedicated surgical instrument (not shown in the drawings) to grasp and rotate the auxiliary rod member <NUM> or to move the clamp members 50A in a direction of getting closer to or farther from each other, thereby correcting the spinal deformity including twisting. Next, as shown in <FIG>, the set screw <NUM> of the corrective appliance 1A according to the first embodiment is fully tightened to fix the auxiliary rod member <NUM> firmly to the groove <NUM> of the rod receiving section <NUM> of each clamp member 50A. In this way, it becomes possible to correct the spinal deformity and to retain the corrected state using the corrective appliance 1A according to the first embodiment. Next, as shown in <FIG>, the rod member <NUM> is engaged with the grooves <NUM> of the rod receiving sections <NUM> of all the screw members <NUM> (ten screw members <NUM>) on the left side without the attached clamp member 50A. Then, using a dedicated surgical instrument (not shown in the drawings), the set screw <NUM> is screwed into the female threads <NUM>, <NUM> of the rod receiving section <NUM> of each screw member <NUM> (see <FIG>) and fully tightened, thereby fixing the rod member <NUM> firmly to the groove <NUM> of the rod receiving section <NUM> of each screw member <NUM>. At this time, the rod member <NUM> may be curved slightly in such a manner as to conform to (physiological) normal backward curvature and forward curvature of the patient, if necessary, and the rod member <NUM> in this state may be engaged with the grooves <NUM> of the rod receiving sections <NUM> of all the screw members <NUM> (ten screw members <NUM>).

Next, as shown in <FIG>, the rod member <NUM> is engaged with the grooves <NUM> of the rod receiving sections <NUM> of all the screw members <NUM> (ten screw members <NUM>) on the right side on which the clamp members 50A are attached. Furthermore, the set screw <NUM> is screwed into the female threads <NUM>, <NUM> of the rod receiving section <NUM> of each screw member <NUM> (see <FIG>) and fully tightened, thereby fixing the rod member <NUM> firmly to the groove <NUM> of the rod receiving section <NUM> of each screw member <NUM>.

Next, as shown in <FIG>, the set screw <NUM> is detached from the rod receiving section <NUM> of each clamp member 50A and the auxiliary rod member <NUM> is detached from each clamp member 50A. Then, each clamp member 50A is detached from the rod receiving section <NUM> of each screw member <NUM>. By doing so, the correction and fusion of the spinal deformity by the spinal deformity correction and fusion system <NUM> (a plurality of the screw members <NUM> and the rod members <NUM> in a pair) is completed. The explanation of the method (not claimed) of detaching the clamp member 50A from the rod receiving section <NUM> of the screw member <NUM> is omitted here as it has already been given above.

In the method (not claimed) shown in <FIG> and <FIG>, the clamp member 50A is attached in such a manner that the rod receiving section <NUM> of this clamp member 50A is arranged external to the rod receiving section <NUM> of the screw member <NUM> as viewed in the crosswise direction of the patient. Alternatively, the clamp member 50A may be attached to the rod receiving section <NUM> of the screw member <NUM> in such a manner that the rod receiving section <NUM> of this clamp member 50A is arranged internal to the rod receiving section <NUM> of the screw member <NUM> as viewed in the crosswise direction of the patient. In the method shown in <FIG> and <FIG>, the clamp member 50A is attached to the rod receiving section <NUM> of each screw member <NUM> on the right side as viewed in the crosswise direction of the patient. Alternatively, the clamp member 50A may be attached to the rod receiving section <NUM> of each screw member <NUM> on the left side as viewed in the crosswise direction. Still alternatively, the clamp member 50A may be attached to the rod receiving section <NUM> of each screw member <NUM> on the both sides as viewed in the crosswise direction.

As described above, in addition to the method (not claimed) shown in <FIG> and <FIG>, correction and fusion of spinal deformity by the spinal deformity correction and fusion system <NUM> may be assisted in response to an intention by an operator by attaching the clamp member 50A to the rod receiving section <NUM> of the selected screw member <NUM> and performing operation for correction using the attached clamp member 50A and the auxiliary rod member <NUM>. In summary, the corrective appliance 1A according to the first embodiment is applicable not only to the method shown in <FIG> and <FIG> but to a method (not claimed) different from the method shown in <FIG> and <FIG> responsive to an intention by an operator.

As described above, the corrective appliance 1A according to the first embodiment of the present invention includes: the clamp member 50A to be attached detachably, for example, to the rod receiving section <NUM> of the screw member <NUM> of the spinal deformity correction and fusion system <NUM> and to be arranged close to the rod receiving section <NUM> of the screw member <NUM>; and the auxiliary rod member <NUM> to be attached detachably to the rod receiving section <NUM> of the clamp member 50A and to be used for correcting spinal deformity.

In this configuration, the clamp member 50A is attached to each of a plurality of the screw members <NUM>, and the auxiliary rod member <NUM> is attached further to the groove <NUM> of the rod receiving section <NUM> of each clamp member 50A. Next, the auxiliary rod member <NUM> is operated, making it possible to correct the spinal deformity properly through each clamp member 50A and each screw member <NUM> and to retain the corrected state. Then, the rod member <NUM> is coupled to the groove <NUM> of the rod receiving section <NUM> of each screw member <NUM> to fix a spine in the corrected state. Next, the auxiliary rod member <NUM> and each clamp member 50A are detached from each screw member <NUM> and then taken out of a body.

During the correction and fusion of the spinal deformity in this way by the spinal deformity correction and fusion system <NUM>, unlike in the conventional case, it is not necessary to engage the rod member <NUM> of the spinal deformity correction and fusion system <NUM> with each screw member <NUM> or each hook member <NUM> fixed to each vertebra under scoliosis deformity including twisting, or to perform operation of giving a curve to the rod member <NUM> of the spinal deformity correction and fusion system <NUM> along the scoliosis deformity or operation of firmly sandwiching the rod member <NUM> and rotating the rod member <NUM> using a dedicated surgical instrument such as a pair of pliers. As a result, it becomes possible to limit damage on the rod member <NUM> as a self-contained member. Furthermore, using the corrective appliance 1A according to the first embodiment allows the rod member <NUM> of the spinal deformity correction and fusion system <NUM> to be easily engaged with (coupled to) the groove <NUM> (<NUM>) of the rod receiving section <NUM> (<NUM>) of each screw member <NUM> (hook member <NUM>). As a result, correction of the spinal deformity by the spinal deformity correction and fusion system <NUM> becomes easier to facilitate implementation of a surgery itself, thereby contributing to reduction in a duration of the surgery.

The clamp member 50A used in the corrective appliance 1A according to the first embodiment of the present invention includes, as a ring-like member to support the rod receiving section <NUM> of the screw member <NUM> in such a manner as to surround an outer periphery of the rod receiving section <NUM>, the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM>, and the rotary member <NUM> rotatably supported in such a manner as to open and close respective tips of the supporting pieces <NUM>, <NUM> in a pair relative to each other. This allows the groove <NUM> provided at the rod receiving section <NUM> of the screw member <NUM> and used for engagement with the rod member <NUM> to be exposed to the outside. As a result, while spinal deformity is corrected and the corrected state is retained using the clamp member 50A and the auxiliary rod member <NUM>, the rod member <NUM> can be engaged easily with the groove <NUM> of each screw member <NUM>.

The clamp member 50A used in the corrective appliance 1A according to the first embodiment of the present invention further includes the set screw <NUM> to be used for fixing the auxiliary rod member <NUM> to the groove <NUM> of the rod receiving section <NUM> of the clamp member 50A. By operating the auxiliary rod member <NUM> while the auxiliary rod member <NUM> is temporarily tightened to the groove <NUM> of each clamp member 50A using the set screw <NUM>, it becomes possible to correct spinal deformity easily through each clamp member 50A. After the correction, the auxiliary rod member <NUM> is fixed firmly to the groove <NUM> of the rod receiving section <NUM> of each clamp member 50A using the set screw <NUM>. By doing so, the spinal deformity can be retained in the corrected state using the clamp member 50A and the auxiliary rod member <NUM>.

The clamp member 50A used in the corrective appliance 1A according to the first embodiment of the present invention further includes the stopper pawl sections <NUM>, <NUM> in a pair for sandwiching the rod receiving section <NUM> of the screw member <NUM>, in addition to the supporting pieces <NUM>, <NUM> in a pair of the screw support <NUM> and the rotary member <NUM> rotatably supported in such a manner as to open and close respective tips of the supporting pieces <NUM>, <NUM> in a pair relative to each other. The stopper pawl sections <NUM>, <NUM> in a pair can be used for fixing the clamp member 50A to the screw member <NUM> more firmly. As a result, force of the correction applied from the clamp member 50A can be transmitted properly to a vertebra through the screw member <NUM>, making it possible to correct spinal deformity properly.

Furthermore, the planar portion <NUM> of the screw member <NUM> is provided with the concaved section <NUM> for supporting the tip of the pawl <NUM> of the stopper pawl section <NUM> of the corrective appliance 1A according to the first embodiment of the present invention. When the clamp member 50A is attached to the screw member <NUM>, the stopper pawl section <NUM> of the clamp member 50A is engaged with the concaved section <NUM> of the screw member <NUM>. This makes it possible to minimize backlash of the clamp member 50A relative to the screw member <NUM> occurring during attachment of the clamp member 50A to the screw member <NUM>.

The corrective appliance 1A according to the first embodiment uses the auxiliary rod member <NUM> as a corrective member to be engaged with the groove <NUM> of the rod receiving section <NUM> of the clamp member 50A. This corrective member may be a shaft member, for example, to be attached detachably to the clamp member 50A and to extend from the clamp member 50A toward the outside of a body. If such a shaft member is used, spinal deformity can be corrected properly by causing an operator to grasp and operate each shaft member projecting to the outside of the body or to operate the shaft member using a surgical instrument. A member such as that for retention of correction for retaining a corrected state may be mounted on a tip of each shaft member.

While the corrective appliance 1A according to the first embodiment functions as a surgical instrument to be taken out of a body after spinal deformity is subjected to correction and fusion by the spinal deformity correction and fusion system <NUM>, it can indwell as it is in the body. In this case, like the screw member <NUM>, the hook member <NUM>, the rod member <NUM>, etc., of the spinal deformity correction and fusion system <NUM>, the corrective appliance 1A according to the first embodiment is required to be made of a material of excellent biocompatibility such as titanium alloy. This allows improvement of the rigidity of the spinal deformity correction and fusion system <NUM> as a whole, making it possible to reduce the occurrence of breakage of the rod member <NUM>, for example.

A corrective appliance 1B according to a second embodiment of the present invention will be described in detail on the basis of <FIG>. In describing the corrective appliance 1B according to the second embodiment, only a difference from the corrective appliance 1A according to the first embodiment will be described. In the corrective appliance 1B of the second embodiment, the configuration of a clamp member 50B used in the corrective appliance 1B differs from that of the clamp member 50A used in the corrective appliance 1A according to the first embodiment. Thus, in the following, the configuration of the clamp member 50B will be described in detail.

As shown in <FIG>, <FIG>, and <FIG>, the clamp member 50B includes: supporting pieces <NUM>, <NUM> in a pair movable closer to and farther from each other to support the rod receiving section <NUM> of the screw member <NUM>; a rod receiving section <NUM> connected integrally to the one supporting piece <NUM> of the supporting pieces <NUM>, <NUM> in a pair and having a U-shape groove <NUM> with an opened upper surface; and a wedge slide member <NUM> to move in the top-bottom direction to make the other supporting piece <NUM> of the supporting pieces <NUM>, <NUM> in a pair movable closer to and farther from the one supporting piece <NUM>. In other words, the clamp member 50B is formed by coupling and integrating a main body unit <NUM> shown in <FIG>, a secondary body unit <NUM> shown in <FIG>, the wedge slide member <NUM> shown in <FIG>, an operative screw member <NUM> shown in <FIG>, and a regulating plate member <NUM> shown in <FIG> each configured using a single part.

As shown in <FIG>, the main body unit <NUM> is formed by connecting the one supporting piece <NUM>, a main body unit section <NUM>, and the rod receiving section <NUM> integrally to each other. The one supporting piece <NUM> extends from the lower end of the main body unit section <NUM> in a direction substantially orthogonal to a direction in which the groove <NUM> of the rod receiving section <NUM> extends. The one supporting piece <NUM> extends from the lower end of the main body unit section <NUM>, which corresponds to one end side as viewed in the direction in which the groove <NUM> of the rod receiving section <NUM> extends. The main body unit section <NUM> has a front side (a side closer to the one supporting piece <NUM>) where an arc-like screw abutting surface <NUM> is provided in such a manner as to be continuous with the one supporting piece <NUM>. One of the arc-like portions <NUM> provided at the rod receiving section <NUM> of the screw member <NUM> shown in <FIG> is to abut on the screw abutting surface <NUM>. The main body unit section <NUM> has a back side (a side on the opposite side of the one sporting piece <NUM>) to which the rod receiving section <NUM> is integrally connected.

A housing hollow section <NUM> is formed in the main body unit section <NUM>. The housing hollow section <NUM> has an opened upper surface having an arbitrary shape, is opened at the other end side as viewed in the direction in which the groove <NUM> of the rod receiving section <NUM> extends, and has an opened front side (a side closer to the one supporting piece <NUM>) having a substantially rectangular shape as viewed in the direction in which the groove <NUM> of the rod receiving section <NUM> extends. A secondary body unit section <NUM> of the secondary body unit <NUM> and the wedge slide member <NUM> described later in detail are housed in the housing hollow section <NUM> while a wedge projection <NUM> provided at the wedge slide member <NUM> is engaged with an inclined space <NUM> provided at the secondary body unit section <NUM>. A housing cavity <NUM> is formed at the upper surface of the main body unit section <NUM> and at one end of the main body unit section <NUM> closer to the one supporting piece <NUM>.

The rod receiving section <NUM> has the U-shape groove <NUM> with the opened upper surface. The groove <NUM> is formed in the direction in which the rod member <NUM> extends (see <FIG>). Walls <NUM>, <NUM> facing each other across the groove <NUM> of the rod receiving section <NUM> have inner wall surfaces at which corresponding female threads <NUM>, <NUM> are formed. A set screw <NUM> shown in <FIG> is screwed into the female threads <NUM>, <NUM>. The set screw <NUM> corresponds to a fixing tool for fixing the auxiliary rod member <NUM> to the groove <NUM> of the clamp member 50B.

The rod receiving section <NUM>, specifically, the wall <NUM>, <NUM> thereof project more upward than the upper surface of the main body unit section <NUM> as shown in <FIG>, and more upward than the regulating plate member <NUM> fixed in such a manner as to cover the upper surface of the main body unit section <NUM> as shown in <FIG>. This allows a rod-like surgical instrument (not shown in the drawings), used for assisting in the operation of inserting the auxiliary rod member <NUM> (see <FIG>) into the groove <NUM> of the rod receiving section <NUM>, to be mounted at its tip on the projecting portions of the walls <NUM>, <NUM>. As shown in <FIG>, the bottom surface of the groove <NUM> of the rod receiving section <NUM> is located above the one supporting piece <NUM>. As shown in <FIG>, the secondary body unit <NUM> is formed by connecting the other supporting piece <NUM> and the secondary body unit section <NUM> to each other integrally. The other supporting piece <NUM> extends from the lower end of the secondary body unit section <NUM> in a direction substantially orthogonal to the direction in which the groove <NUM> of the rod receiving section <NUM> extends. The other supporting piece <NUM> extends from the lower end of the secondary body unit section <NUM>, which corresponds to the other end side as viewed in the direction in which the groove <NUM> of the rod receiving section <NUM> extends.

The secondary body unit section <NUM> includes: a plate-like body <NUM> having a plate-like shape of a predetermined width and extending in a standing position in the direction in which the groove <NUM> of the rod receiving section <NUM> extends; and a large inclination piece 175A and a small inclination piece 175B in a pair connected integrally to the back surface (a surface on the opposite side of the other supporting piece <NUM>) of the plate-like body <NUM>. An arc-like screw abutting surface <NUM> is provided spaced from and below the plate-like body <NUM> of the secondary body unit section <NUM> in such a manner as to be continuous with the other supporting piece <NUM>. One of the arc-like portions <NUM> at the rod receiving section <NUM> of the screw member <NUM> shown in <FIG> is to abut on the screw abutting surface <NUM>. The inclined space <NUM> of a predetermined width inclined downward toward the other supporting piece <NUM> (toward the other end) is formed between the large inclination piece 175A and the small inclination piece 175B in a pair. The thickness of the small inclination piece 175B on one end side is smaller than that of the large inclination piece 175A on the other end side. The wedge projection <NUM> provided at the wedge slide member <NUM> (see <FIG>) is engaged with the inclined space <NUM>.

As shown in <FIG>, the wedge slide member <NUM> includes a plate-like section <NUM> and a cylindrical section <NUM> connected integrally to one end portion of the plate-like section <NUM>. The wedge slide member <NUM> is housed in its entirety in the housing hollow section <NUM> at the main body unit section <NUM> of the main body unit <NUM>. The plate-like section <NUM> is provided in a standing position, and has a front side where the wedge projection <NUM> projects at the other end on the opposite side of the cylindrical section <NUM>. The wedge projection <NUM> is formed into a shape like a parallelogram in a front view having a predetermined width and inclined downward toward an attachment bolt <NUM> (toward the other end). The wedge projection <NUM> is engaged with the inclined space <NUM> at the secondary body unit <NUM> and has a width substantially equal to that of the inclined space <NUM>. The cylindrical section <NUM> has an inner peripheral surface provided with female threads (not shown in the drawings). Male threads <NUM> of the operative screw member <NUM> are threadedly engaged with these female threads.

The operative screw member <NUM> is composed of a head <NUM> having an upper surface with a hexagonal hole <NUM>, and the male threads <NUM> provided continuously in an axis direction from the head <NUM>. The male threads <NUM> are threadedly engaged with the female threads provided at the inner peripheral surface of the cylindrical section <NUM> of the wedge slide member <NUM>. The head <NUM> of the operative screw member <NUM> is housed in the housing cavity <NUM> provided at the upper surface of the main body unit section <NUM> of the main body unit <NUM>. The regulating plate member <NUM> for regulating the movement of the operative screw member <NUM> in the top-bottom direction is arranged on the head <NUM> of the operative screw member <NUM>. Specifically, as shown in <FIG>, the head <NUM> of the operative screw member <NUM> is sandwiched between the housing cavity <NUM> of the main body unit <NUM> (main body unit section <NUM>) and the regulating plate member <NUM> to support the operative screw member <NUM> rotatably while being unmovable in the top-bottom direction.

The regulating plate member <NUM> is provided with an opening <NUM> formed at a position corresponding to the head <NUM> of the operative screw member <NUM> so as to expose the hexagonal hole <NUM> at the head <NUM> of the operative screw member <NUM> to the outside. As shown in <FIG>, the regulating plate member <NUM> is fixed to the main body unit <NUM> with the attachment bolt <NUM> in such a manner as to cover the upper surface of the main body unit section <NUM> of the main body unit <NUM> and the head <NUM> of the operative screw member <NUM>. As described above, as the opening <NUM> is formed at the regulating plate member <NUM>, the hexagonal hole <NUM> at the head <NUM> of the operative screw member <NUM> is exposed to the outside.

While the wedge projection <NUM> at the wedge slide member <NUM> is engaged with the inclined space <NUM> at the secondary body unit <NUM>, the secondary body unit section <NUM> of the secondary body unit <NUM> and the wedge slide member <NUM> are arranged in the housing hollow section <NUM> of the main body unit <NUM>. In this state, the wedge slide member <NUM> is housed movably in the top-bottom direction and the secondary body unit <NUM> is housed movably in the direction in which the groove <NUM> of the rod receiving section <NUM> extends. As a result, as shown in <FIG>, the one supporting piece <NUM> of the main body unit <NUM> and the other supporting piece <NUM> of the secondary body unit <NUM> are arranged in such a manner as to face each other.

The male threads <NUM> of the operative screw member <NUM> are arranged in the housing hollow section <NUM> of the main body unit <NUM> while being threadedly engaged with the female threads at the cylindrical section <NUM> of the wedge slide member <NUM>. The head <NUM> of the operative screw member <NUM> is housed in the housing cavity <NUM> of the main body unit <NUM> (main body unit section <NUM>), and the upper surface of the head <NUM> and the upper surface of the main body unit <NUM> (main body unit section <NUM>) except the housing cavity <NUM> are arranged on substantially the same plane. Furthermore, the regulating plate member <NUM> is arranged in such a manner as to cover the upper surface of the main body unit section <NUM> of the main body unit <NUM> and the head <NUM> of the operative screw member <NUM>, and is fixed with the attachment bolt <NUM> to the main body unit <NUM>. In this way, the clamp member 50B used in the corrective appliance 1B according to the second embodiment is completed.

For attachment of the clamp member 50B of the corrective appliance 1B according to the second embodiment to the rod receiving section <NUM> of the screw member <NUM>, a dedicated surgical instrument not shown in the drawings is fitted in the hexagonal hole <NUM> of the head <NUM> of the operative screw member <NUM> and the dedicated surgical instrument is operated to one direction, thereby rotating the operative screw member <NUM> to the one direction. As a result, as the operative screw member <NUM> is supported in such a manner as to be unmovable in the top-bottom direction, the wedge slide member <NUM> is moved upward. This produces wedge effect between the wedge projection <NUM> at the wedge slide member <NUM> and the large inclination piece 175A and the small inclination piece 175B in a pair at the secondary body unit section <NUM> of the secondary body unit <NUM> to move the other supporting piece <NUM> of the secondary body unit <NUM> in a direction of getting father from the one supporting piece <NUM> of the main body unit <NUM>.

Next, the clamp member 50A is arranged in such a manner as to locate the supporting pieces <NUM>, <NUM> in a pair thereof at positions on the planar portions <NUM>, <NUM> in a pair of the rod receiving section <NUM> of the screw member <NUM> below the groove <NUM>. At this time, one of the arc-like portions <NUM> of the rod receiving section <NUM> of the screw member <NUM> comes into abutting contact with the screw abutting surface <NUM> belonging to the main body unit <NUM> of the clamp member 50A and with the screw abutting surface <NUM> belonging to the secondary body unit <NUM>.

Next, the dedicated surgical instrument not shown in the drawings is fitted again in the hexagonal hole <NUM> of the head <NUM> of the operative screw member <NUM> and the fitted dedicated surgical instrument is rotated to the opposite direction, thereby rotating the operative screw member <NUM> to the opposite direction. As a result, the wedge slide member <NUM> moves downward to produce wedge effect between the wedge projection <NUM> at the wedge slide member <NUM> and the large inclination piece 175A and the small inclination piece 175B in a pair at the secondary body unit section <NUM> of the secondary body unit <NUM>, thereby moving the other supporting piece <NUM> of the secondary body unit <NUM> in a direction of getting closer to the one supporting piece <NUM> of the main body unit <NUM>.

As a result, it becomes possible to firmly clamp the screw member <NUM> at positions on the planar portions <NUM>, <NUM> in a pair of the rod receiving section <NUM> below the groove <NUM> in such a manner as to clamp the screw member <NUM> from opposite lateral sides using the supporting pieces <NUM>, <NUM> in a pair of the clamp member 50B. At this time, as the screw member <NUM> is sandwiched at the positions on the planar portions <NUM>, <NUM> in a pair of the rod receiving section <NUM> of the screw member <NUM> below the groove <NUM> using the supporting pieces <NUM>, <NUM> in a pair of the clamp member 50B, the groove <NUM> of the screw member <NUM> (rod receiving section <NUM>) can be exposed to the outside.

Claim 1:
A corrective appliance (1A, 1B) for assisting in correction and fusion when spinal deformity is subjected to the correction and fusion by a spinal deformity correction and fusion system (<NUM>) including a vertebra fixing tool (<NUM>, <NUM>) to be fixed to each vertebra of a spine and a rod member (<NUM>) to be coupled to the vertebra fixing tool (<NUM>, <NUM>), the corrective appliance (1A, 1B) comprising:
a clamp member (50A, 50B) to be attached detachably to the vertebra fixing tool (<NUM>, <NUM>) and to be arranged close to the vertebra fixing tool (<NUM>, <NUM>); and
a corrective member (<NUM>) to be attached detachably to the clamp member (50A, 50B) and to be used for correcting the spinal deformity,
characterized in that the clamp member (50A, 50B) includes supporting pieces (<NUM>) in a pair movable closer to and farther from each other to support a head of the vertebra fixing tool (<NUM>, <NUM>) in such a manner as to sandwich the head.