Not Applicable.
This invention relates to spinal surgery methods and associated apparatus.
Spinal surgery for spinal deformities, such as scoliosis and kyphosis, is often performed on children who have not finished growing. Scoliosis surgery usually includes correction of the deformity, and a variety of techniques are used to correct the curve. In the majority of cases, the surgery is done using the posterior approach by fixing either pedicle screws or hooks, that is fixation devices, into the vertebrae. These fixation devices are used to correct the spinal deformity by either: (1) using precontoured rod(s) to reduce the spinal deformity to the contoured rod through the fixation devices; or (2) bending the rod(s) to fit into the fixation devices and then correct the curve by rotating the rod(s) and/or rotating the spine around the rod(s) and/or distraction/compression between the fixation devices along the rod(s); or (3) a combination of the above two techniques. In all these cases, the fixation needs to span from above the deformity to below the deformity.
For curves that are primarily in the lumbar spine, an anterior approach has been used to directly derotate the apex of the curve by first inserting vertebral screws into the vertebral body, putting in a contoured rod into the tulip shaped heads of the screws, and then rotating the rod in the tulip shaped heads of the screws.
The anterior approach does not need fixation above and below the deformity and therefore, the length of the fusion would be shorter than if the posterior methods discussed above are used. However, the anterior approach has its issues including limited number of levels that can be instrumented from a single approach, and the complications associated with the anterior approach such as intercostal neuritis and abdominal hernia.
Therefore, what is needed is an improved method and apparatus to manipulate the curvature of the spine.
The present invention meets the foregoing needs. In one aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises a connector comprising a rod having a first end section and a second end section wherein the rod is dimensioned to connect a pair of pedicle screws, and a fastener attached to the rod wherein the fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod. In one embodiment, the fastener is located at the first end section of the rod. In one embodiment, the fastener is located between the first end section and the second end section of the rod.
In one embodiment, an additional fastener is attached to the rod wherein the additional fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod. The fastener can be located at the first end section of the rod, and the additional fastener can be located at the second end section of the rod.
The bone surgical apparatus can further comprise a plurality of additional fasteners attached to the rod, wherein at least one of the additional fasteners comprises a head including spaced apart walls defining a recess for receiving an alignment rod.
The bone surgical apparatus can further comprise a second fastener attached to the rod wherein the second fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod, and a third fastener attached to the rod wherein the third fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod, wherein the fastener is located at the first end section of the rod, wherein the second fastener is located at the second end section of the rod, and wherein the third fastener is located between the first end section and the second end section of the rod.
In one embodiment of the bone surgical apparatus, a longitudinal axis of the head of the fastener is polyaxial with respect to a longitudinal axis of the rod.
The bone surgical apparatus can further comprise a pair of pedicle screws configured to attach to a vertebra and dimensioned to receive the rod of the connector.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector, a second connector comprising a second rod having a first end section and a second end section wherein the second rod is dimensioned to connect a pair of pedicle screws, and a second fastener attached to the second rod wherein the second fastener comprises a head including spaced apart walls defining a recess for receiving the alignment rod, and a second pair of pedicle screws configured to attach to a second vertebra, the second pair of pedicle screws being attached to the second rod of the second connector.
The bone surgical apparatus can further comprise an alignment rod connected to the fastener of the rod and the second fastener of the second rod. In one embodiment, the fastener is located between the first end section and the second end section of the rod, and the second fastener is located between the first end section and the second end section of the second rod.
The bone surgical apparatus can further comprise a first additional fastener attached to the first end section of the rod. The bone surgical apparatus can further comprise a second additional fastener attached to the second end section of the rod. The bone surgical apparatus can further comprise a second alignment rod connected to the first additional fastener and the second additional fastener, and a third alignment rod connected to the first additional fastener and the second additional fastener.
In one embodiment, the fastener is located at the first end section of the rod, and the second fastener is located at the first end section of the second rod.
The bone surgical apparatus can further comprise a first additional fastener attached to the second end section of the rod, a second additional fastener attached to the second end section of the second rod, and a second alignment rod connected to the first additional fastener and the second additional fastener. In one embodiment, the first additional fastener comprises a head including spaced apart walls defining a recess for receiving the second alignment rod, and the second additional fastener comprises a head including spaced apart walls defining a recess for receiving the second alignment rod.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector; an additional pedicle screw configured to attach to a second vertebra, the additional pedicle screw being connected to a fusion rod; and an angled rod, wherein the fastener is located at the first end section of the rod, and wherein the angled rod is connected to the fastener and the fusion rod.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector; an additional pedicle screw configured to attach to a second vertebra, the additional pedicle screw being connected to a fusion rod; and an angled rod, wherein the fastener is located at the first end section of the rod, and wherein the angled rod is connected to the fastener and the fusion rod.
In one embodiment, the first end section of the rod and the second end section of the rod are connected by a hinge. A first section of the hinge can be attached to the first end section of the rod, a second section of the hinge can be attached to the second end section of the rod, and the hinge can include a locking device for locking the hinge in one of a plurality of relative positions between the first section of the hinge and the second section of the hinge.
In one embodiment, the first end section of the rod and the second end section of the rod are connected by an adjustment mechanism structured to retain the first end section of the rod and the second end section of the rod at any of a plurality of distances between the first end section of the rod and the second end section of the rod thereby providing for variable lengths of the rod. The adjustment mechanism can be connected by a hinge to at least one of the first end section of the rod and the second end section of the rod.
The bone surgical apparatus can further comprise a first pedicle screw and a second pedicle screw configured to attach to a first vertebra, the rod of the connector being attached to the first pedicle screw, the fastener being located at the first end section of the rod; a third pedicle screw and a fourth pedicle screw configured to attach to a second vertebra; and a fixator having a first end section and a second end section, the first end section of the fixator being attached to the fastener and the second pedicle screw, and the second end section of the fixator being attached to the fourth pedicle screw. In one embodiment, the first end section of the fixator comprises an alignment rod, a first end of the alignment rod is received in the recess of the fastener for attachment to the fastener, and a second end of the alignment rod is received in a recess in a head of the second pedicle screw for attachment to the second pedicle screw. A method for manipulating a curvature of a spine of a subject can include the steps of (i) surgically implanting the bone surgical apparatus into a subject such that the first pedicle screw and the second pedicle screw are attached to the first vertebra and the third pedicle screw and the fourth pedicle screw are attached to the second vertebra; (ii) moving the fixator to achieve a desired alignment of the first vertebra and the second vertebra; (iii) removing the connector from the first pedicle screw; and (iv) attaching an alignment rod to the first pedicle screw and the third pedicle screw.
In another aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises a connector comprising a rod having a first end section and a second end section wherein the rod is dimensioned to connect a pair of pedicle screws, and a fastener attached to the rod wherein the fastener comprises sections for clamping a band. In one embodiment, the fastener is located at the first end section of the rod.
The bone surgical apparatus can further comprise a second fastener attached to the rod wherein the second fastener comprises sections for clamping a second band, wherein the fastener is located at the first end section of the rod, wherein the second fastener is located between the first end section and the second end section of the rod.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector, a second connector comprising a second rod having a first end section and a second end section wherein the second rod is dimensioned to connect a pair of pedicle screws, and a second fastener attached to the second rod, wherein the second fastener comprises a sections for clamping a band; a second pair of pedicle screws configured to attach to a second vertebra, the second pair of pedicle screws being attached to the second rod of the second connector, and a band connected to the fastener and the second fastener. In one embodiment, a first additional fastener attached to the rod between the first end section and the second end section of the rod; a second additional fastener attached to the second rod between the first end section and the second end section of the second rod; a second band connected to the first additional fastener and the second additional fastener; and a sheath surrounding the second band.
In another aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises a connector comprising a rod having a first end section and a second end section wherein the rod is dimensioned to connect a pair of pedicle screws, and a latch attached to the first end section of the rod wherein the latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop. In one embodiment, an additional latch is attached to the second end section of the rod wherein the additional latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop. In one embodiment, the first wall has a first terminal end, the second wall has a second terminal end, the first terminal end and the second terminal end are positioned to define a space between the first terminal end and the second terminal end, the latch includes a movable barrier for opening and closing the space between the first terminal end and the second terminal end, the portion of the loop is received in the interior region when the space is open, and the portion of the loop is retained in the interior region when the space is closed.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector, a second connector comprising a second rod having a first end section and a second end section wherein the second rod is dimensioned to connect a pair of pedicle screws, and a second latch attached to the first end section of the second rod wherein the second latch comprises a first wall and a second wall defining an interior region for receiving a portion of the loop, a second pair of pedicle screws configured to attach to a second vertebra, the second pair of pedicle screws being attached to the second rod of the second connector, and a loop having a first portion retained in the interior region of the latch and a second portion retained in the interior region of the second latch. In one embodiment, the loop is dimensioned such that the loop is tensioned when retained in the interior region of the latch and retained in the interior region of the second latch.
The bone surgical apparatus can further comprise a first additional latch attached to the second end section of the rod, wherein the first additional latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop, a second additional latch attached to the second end section of the second rod, wherein the second additional latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop, and a second loop having a first portion retained in the interior region of the first additional latch and a second portion retained in the interior region of the second additional latch.
The bone surgical apparatus can further comprise a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the rod of the connector; a second connector comprising a second rod having a first end section and a second end section wherein the second rod is dimensioned to connect a pair of pedicle screws, and a fastener attached to the second rod wherein the fastener comprises a head including spaced apart walls defining a recess for receiving a rod; a second pair of pedicle screws configured to attach to a second vertebra, the second pair of pedicle screws being attached to the second rod of the second connector; a third connector comprising a third rod having a first end section and a second end section wherein the third rod is dimensioned to connect a pair of pedicle screws, and a second latch attached to the first end section of the third rod wherein the second latch comprises a first wall and a second wall defining an interior region for receiving a portion of the loop, the third rod being attached to the fastener of the second connector; and a loop having a first portion retained in the interior region of the latch and a second portion retained in the interior region of the second latch. In one embodiment, the loop is formed from a band of material. In one embodiment, the loop is formed from a tubular material.
The bone surgical apparatus can further comprise a fastener attached to the second end section of the rod wherein the fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod.
The bone surgical apparatus can further comprise a fastener attached to the rod between the first end section and the second end section, wherein the fastener comprises a head including spaced apart walls defining a recess for receiving an alignment rod.
In one embodiment, the first end section of the rod and the second end section of the rod are connected by a hinge. A first section of the hinge can be attached to the first end section of the rod, a second section of the hinge can be attached to the second end section of the rod, and the hinge can include a locking device for locking the hinge in one of a plurality of relative positions between the first section of the hinge and the second section of the hinge.
In one embodiment, the first end section of the rod and the second end section of the rod are connected by an adjustment mechanism structured to retain the first end section of the rod and the second end section of the rod at any of a plurality of distances between the first end section of the rod and the second end section of the rod thereby providing for variable lengths of the rod. In one embodiment, the adjustment mechanism is connected by a hinge to at least one of the first end section of the rod and the second end section of the rod.
In another aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises a latch connector comprising a rod adapter dimensioned to attach to a fusion rod, a central section attached to the rod adapter wherein the central section is dimensioned to attach to a head of a pedicle screw, and a latch attached to the central section wherein the latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop. In one embodiment, the first wall has a first terminal end, the second wall has a second terminal end, the first terminal end and the second terminal end are positioned to define a space between the first terminal end and the second terminal end, the latch includes a movable barrier for opening and closing the space between the first terminal end and the second terminal end, the portion of the loop is received in the interior region when the space is open, and the portion of the loop is retained in the interior region when the space is closed.
The bone surgical apparatus can further comprise a fusion rod; a first connector comprising a first rod having a first end section and a second end section wherein the first rod is dimensioned to connect a pair of pedicle screws, and a first fastener attached to the first rod wherein the first fastener comprises a first head including spaced apart walls defining a first recess, the fusion rod being positioned in the first recess and being connected to the first head; a first pair of pedicle screws configured to attach to a first vertebra, the first pair of pedicle screws being attached to the first rod of the first connector; a second connector comprising a second rod having a first end section and a second end section wherein the second rod is dimensioned to connect a pair of pedicle screws, and a second fastener attached to the second rod wherein the second fastener comprises a second head including spaced apart walls defining a second recess, the fusion rod being positioned in the second recess and being connected to the second head; a second pair of pedicle screws configured to attach to a second vertebra, the second pair of pedicle screws being attached to the second rod of the second connector; a third connector a third rod having a first end section and a second end section wherein the third rod is dimensioned to connect a pair of pedicle screws, and a second latch attached to the first end section of the third rod wherein the second latch comprises a first wall and a second wall defining an interior region for receiving a portion of the loop; a third pair of pedicle screws configured to attach to a third vertebra, the third pair of pedicle screws being attached to the third rod of the third connector; and a loop having a first portion retained in the interior region of the latch and a second portion retained in the interior region of the second latch, wherein the rod adapter of the latch connector is attached to the fusion rod, and the central section of the latch connector is attached to the second head of the second fastener.
In one embodiment, the rod adapter of the latch connector is attached to the fusion rod by a set screw. In one embodiment, the central section of the latch connector surrounds the second head of the second fastener to engage the second head of the second fastener when the latch connector is attached to the second head of the second fastener.
In another aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises an adjustment mechanism comprising a first rod section having an inner end and an outer end, a second rod section having an inner end and an outer end having an outer surface shape, and a hinge attached to the inner end of the first rod section and to the inner end of the second rod section, wherein the outer end of the first rod section comprises a wall defining a recess dimensioned for receiving a rod end section having a perimeter shaped the same as the outer surface shape of the outer end of the second rod section. A first section of the hinge can be attached to the inner end of the first rod section, a second section of the hinge can be attached to the inner end of the second rod section, and the hinge can include a locking device for locking the hinge in one of a plurality of relative positions between the first section of the hinge and the second section of the hinge.
The bone surgical apparatus can further comprise a second adjustment mechanism comprising a third rod section having an inner end and an outer end, a fourth rod section having an inner end and an outer end having an outer surface shape, and a second hinge attached to the inner end of the third rod section and to the inner end of the fourth rod section, wherein the outer end of the third rod section comprises a wall defining a recess dimensioned for receiving the outer end of the second rod section. The hinge can include a ratchet for controlling motion in both of a first rotational direction and an opposite second rotational direction of the hinge.
The bone surgical apparatus can further comprise a first pedicle screw configured to attach to a first vertebra, the first rod section being attached to the first pedicle screw; and a second pedicle screw configured to attach to a second vertebra, the fourth rod section being attached to the second pedicle screw, wherein the outer end of the second rod section is received in the recess in the outer end of the third rod section. In one embodiment, the outer end of the second rod section is secured in the recess in the outer end of the third rod section by a set screw. In one embodiment, the outer end of the second rod section is secured in the recess in the outer end of the third rod section by an interference fit. In one embodiment, a first section of the second hinge is attached to the inner end of the third rod section, a second section of the second hinge is attached to the inner end of the fourth rod section, and the second hinge includes a locking device for locking the second hinge in one of a plurality of relative positions of the second hinge between the first section of the second hinge and the second section of the second hinge. In one embodiment, the hinge is locked in one of the plurality of relative positions of the hinge by a first set screw, and the second hinge is locked in one of the plurality of relative positions of the second hinge by a second set screw.
The bone surgical apparatus can further comprise a fusion rod; a first pedicle screw configured to attach to a first vertebra, the fusion rod being attached to the first pedicle screw; a second pedicle screw configured to attach to a second vertebra, the second rod section being attached to the second pedicle screw, wherein an end of the fusion rod is received in the recess in the outer end of the first rod section. In one embodiment, the end of the fusion rod is secured in the recess in the outer end of the first rod section by a set screw.
In another aspect, the disclosure provides a bone surgical apparatus for manipulating a curvature of a spine. The bone surgical apparatus comprises a first pedicle screw and a second pedicle screw configured to attach to a first vertebra; a third pedicle screw and a fourth pedicle screw configured to attach to a second vertebra; and a fixator having a first end section and a second end section, the first end section of the fixator including a hinged rod attached to the first pedicle screw, and the second end section of the fixator being attached to the fourth pedicle screw. In one embodiment, a first end of the hinged end is received in a recess in a head of the first pedicle screw for attachment to the first pedicle screw, a second end of the hinged end is received in a recess in a head of the second pedicle screw for attachment to the second pedicle screw and the second end section of the fixator is received in a recess in a head of the fourth pedicle screw for attachment to the fourth pedicle screw. A method for manipulating a curvature of a spine of a subject can include the steps of (i) surgically implanting the bone surgical apparatus into a subject such that the first pedicle screw and the second pedicle screw are attached to the first vertebra and the third pedicle screw and the fourth pedicle screw are attached to the second vertebra; (ii) moving the fixator to achieve a desired alignment of the first vertebra and the second vertebra; (iii) removing the hinged end from the recess in the head of the first pedicle screw; and (iv) attaching an alignment rod to the first pedicle screw and the third pedicle screw.
The present disclosure provides a bone surgical apparatus with or without a hinge/ratchet that can be used to correct spinal deformity with or without spinal fusion.
The present disclosure provides an approach using devices that use intravertebral inter-pedicle-screw rod(s) with fasteners (that can have a tulip-shaped section) at the ends such that short fusion can be done using the posterior approach without the complications associated with the anterior approach. In this approach, each vertebra at the apex of the deformity is individually fixed to pedicle screws and the device is placed into the two pedicle screws of each vertebra. Then each vertebra is directly manipulated using a combination of rotational, compression, and distraction forces such that the curve is corrected. The correction does not require precontoured rod(s) between the vertebrae. However, once the correction is achieved, a precontoured rod can be used to hold the curve correction.
If the same correction forces, such as rotational forces, are applied directly to the pedicle screws, then the screw would just rotate in the pedicle and the vertebra would not be manipulated. Rotational forces would cause the hooks to move or come out of their insertion sites. Therefore, direct manipulation of each vertebra requires one or more devices of the invention.
Another benefit of the device is that corrective forces are applied and the stress of the forces would be shared by the two pedicle screws in the same vertebra. Therefore, greater corrective forces can be applied.
Another benefit is that since each vertebra is manipulated directly, one can also directly adjust lordosis and kyphosis.
In certain embodiments, the connector rod can be a straight rod, or have a connector in the middle to allow for variable length of the rod or have a hinge within the rod or a combination of variable length as well as a hinge.
This process, which can be referred to Direct Vertebral ReAlignment (DVRA), allows surgeons to directly address the spinal deformity at its apex without extending the spinal construct to above and below the deformity. Therefore, shorter fusions can be done. For example, one of the more common fusions for adolescent idiopathic scoliosis is done from T4 to L1 for a total of ten levels. Typically, this type of curve can be corrected by manipulating and fusing four to seven vertebrae.
This is even more important in very young children who need “growing” rods for their scoliosis. Most current “growing rods” rely on distraction across the deformity with instruments above and below the deformity. Using DVRA, the surgeon can directly manipulate the apex of the curve and allow the rest of the spine to grow. The concept is similar to the Shilla technique except in the Shilla technique, the apex is fused and the rest of the spine is allowed to “grow” over the two rods. In this method, the growth is not inhibited by or limited to the rods.
The present invention provides a method and apparatus that overcome the aforementioned issues by directly correcting the curve of the spine by tethering of the convexity of the curve rather than distracting the spine. Scoliosis surgery often includes correction of the deformity and a variety of techniques are used to correct the curve. In majority of cases, they can be divided into two categories: one is to use precontoured rod(s) to reduce the spinal curvature to the contoured rod; and the second is to stabilize the curve above and below the curve with contoured rod(s) and then correct the curve by rotating the rod(s) and/or rotating the spine around the rod(s). In both of these cases, the fixation needs to span from above the deformity to below the deformity.
For curves that are primarily in the lumbar spine, an anterior approach can be used to directly derotate the apex of the curve by first inserting vertebral screws, putting in a contoured rod into the fastener heads of the screws and then rotating it in the fastener heads of the screws. In all these cases, the correction involves using precontoured rods and/or fixation that spans to above and below the deformity. In addition, in the anterior approach has its issues including limited number of levels that can be instrumented from a single approach.
In the approach of the present invention, the apex of the deformity is directly re-aligned without relying on a contoured rod and using a posterior approach. The reason the rod is necessary in the prior approaches discussed above is that trying to manipulate the vertebrae through the screws without the rod would result in the pedicle screws turning rather than correction of the curve. To directly realign the vertebrae, the solution is to place a rod between a pair of pedicle screws within the same vertebra, that is between the screws in the right and left pedicle of a single vertebra. Then using the devices of the present invention that are used to derotate the vertebra, each vertebra can be directly realigned. Once realigned, an external fixation system that can clamp on the rod can be used to hold the desired alignment.
A next step may be to free up the fastener heads of the pedicle screws on one side so that a rod can be placed for the fusion. In one version of this invention, the rod has a hinge so that it can bend in one plane. The pedicle screws in the same vertebra tend to converge and so the tulip shaped heads are not colinear. The hinged rod can be bent so that the rods on the two sides of the fastener head each can fit exactly into each fastener head; this is much more difficult with solid rods when non-polyaxial screws are used.
If the hinge is aligned so that the rod can bend in a plane parallel to the fastener head of the pedicle screw, then, once the external fixation is applied to the rod on the one side of the hinge (called the first side) to hold the alignment in place, then the set caps on the other side (called the second side) can be removed and the rods can be bent at the hinges so that they are out of the tulip shaped heads of the second side. Then a rod can be placed into the fastener heads on the second side and stabilized with set caps. Then the external fixator can be removed followed by the set caps on first side followed by removal of the hinged rods. Then another rod can be placed into the empty tulip shaped heads of the first side to complete the instrumentation.
Hinged rods of the present invention can also be used for correction of spinal deformity including scoliosis and kyphosis. A rod with multiple hinges can be used to reduce the scoliosis as well as it can provide rotational force to correct the rotational deformity.
Scoliosis is a complex rotational deformity and so these hinged rods can be designed with a male component on one end and female component on the other end so that they can be interlinked and so that the male component can freely rotate until locked in placed using set screws. This would allow for multiplanar correction of the spinal deformity scoliosis. In a similar fashion, kyphosis can be corrected as well.
These and other features, aspects and advantages of various embodiments of the present invention will become better understood with regard to the following description, appended claims and accompanying Figures.
Like reference numerals will be used to refer to like parts from Figure to Figure in the following detailed description.
Embodiments of the invention may further be understood with reference to the Figures. Referring to
Referring to
With continued reference to
Yet other embodiments of the present disclosure include pedicle screws that enable essentially only one degree of freedom of motion with respect to the screw shaft, which is a more restricted form of motion. In still other embodiments, the pedicle screw comprises a screw and head formed as a monolithic component. In this case, the head is no longer polyaxial, but is rather fixed relative to the screw head and shaft. The head of the pedicle screw may also be convertible from polyaxial to monoaxial using structures described in PCT Patent Application Publication No. WO 2017/035186. Although various structures and methods for restraining vertical movement of a polyaxial head that is separate from a screw head have been described herein, it is understood that additional or alternative structures and/or methods may be utilized in alternative embodiments.
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In the connector 210, the hinge 224 can be freely moving or lockable, The hinge 224 can be locked in place by a set screw 225. Alternatively, a hex nut can be turned to lock separate parts of the hinge together. A captured screw can also be used to lock separate parts of the hinge together.
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Another embodiment of the invention is particularly advantageous for non-fusion scoliosis surgery. In this embodiment of the invention, there is a clamp at the end of the rod. These rods can be placed such that the clamps are along the convexity of the curve and a band is placed in the clamps such that the convexity of the curve is prevented from lengthening while the concavity of the curve continues to lengthen, resulting in a decrease of the curve. Turning to
Referring now to
One potential problem with posterior tethering is that the spine can go into extension as posterior growth is potentially reduced more than anterior growth. To limit this effect, one can use a rod 820 with a clamp in the middle as well as a clamp 840 along the convexity of the curve as shown in
The present invention also provides for Direct Vertebral ReAlignment (DVRA) using an IVIP rod with a latch for posterior short fusion and non-fusion treatment of scoliosis. Because the two pedicle screws provide two points of fixation in the vertebra, IVIP rods can convert compression force to rotational force that alters the vertebral tilt. IVIP rods can serve as levers such that less force is needed when the force is applied lateral to the pedicle than at the pedicle. The advantages of DVRA include (1) shorter fusions and shorter operative time and blood loss; (2) more anatomic correction; (3) DVRA can also be used in congenital scoliosis instead of growing rods; and (4) the concept is to use the posterior approach but use the concepts for the anterior approach without the risks of the anterior surgery.
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The latch does not need to have a space providing an opening. One option is to have a tensioning device similar to bands used for spinal fusion. The anchor would be placed on one wall of the latch and a band would go around the limb of the adjacent latch. Another option is to have a way of fusing or suturing or tying the band so that the band can be placed in the adjacent latch without the need for an opening.
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With growth, the convexity is tethered and its growth limited. The concavity will continue to grow, accelerated secondary to distraction, to correct the vertebral tilt between two vertebrae; as the angle between the two vertebrae is corrected at each level, the scoliosis is also corrected. Compare
One of the challenges of tethering has been the risk for overcorrection as the convexity of the spine is tethered. A rod with a latch on both ends can be used to prevent overcorrection. Looking at
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As the concavity grows, the loop 1010 on the left (previous concave side would become taut). As this loop 1010 is the same length as the loop 1010 on the right side, when both sides are at equal length, the tension in the loops 1010 should also be equal, preventing growth on the left side and overcorrection. See
In addition, in patients with kyphosis, if instrumentation is done with a rod with two ring latches and bands on each side with equal tension as shown in
In some clinical situations, the treatment of the spine involves a combination of fusion linked to tethering. This approach allows for limited fusion in spines with little to no growing potential. The present invention also allows for fusion of the primary curve and tethering of the secondary curve. One method to accomplish this is to place the latch in the side limb, rather than at the end. The rod portion would be used for fusion and a band can be placed in the rings for tethering. Turning to FIG. 20, there is shown an embodiment of a bone surgical apparatus according to the invention. A connector 1210 includes a rod 1220 having a first end section and a second end section wherein the rod 1220 is dimensioned to connect a pair of pedicle screws 24. A latch 1230 is attached to the first end section of the rod 1220 wherein the latch 1230 comprises a first wall 1231 and a second wall 1232 defining an interior region 1237 for receiving a portion of a loop. The first terminal end and the second terminal end are positioned to define a space (like 960 in
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Another option is a latch connector device that includes multiple parts. A first part is a latch attached to a central section wherein the latch comprises a first wall and a second wall defining an interior region for receiving a portion of a loop. A second part is a central section that fits around a fastener and the rod in the fastener. A third part is a rod adapter sits around the rod and can be fastened to the rod, for example, by an interference screw. Referring to
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The loop 1010 placed into the latches 930, 1330 can tether the convexity of the curve using the lever advantage of the rods 520, 920.
Another variation of the invention is a rod with a latch and a polyaxial fastener. The fastener could be at the end of the rod or the middle of the rod. The rod portion can have a hinge with variable angle and/or a telescoping rod making the length adjustable as in
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Thus, there are at least three applications of IVIP rods of the invention: (1) fusion for pediatric and young adult spinal deformity; (2) special situations such as extension of fusion; and (3) non-fusion scoliosis surgery, often described as “tethering”, using a posterior approach to the spine (tethering for scoliosis has been almost exclusively done anteriorly).
The advantage of the rods of the invention is that it also acts as a lever. For example, the center of rotation between adjacent vertebrae is at the center of the disc. Using current techniques, the forces are applied at the pedicles.
The first rod section 1511 and the second rod section 1521 of the adjustment mechanism 1510 are assembled to pairs of pedicle screws 24 in vertebrae 10 using set screws 40 in the general arrangement shown in the embodiment of
In an alternative embodiment in
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Thus, the present invention provides a bone surgical apparatus and method for manipulating a curvature of a spine.
In light of the principles and example embodiments described and illustrated herein, it will be recognized that the example embodiments can be modified in arrangement and detail without departing from such principles. Also, the foregoing discussion has focused on particular embodiments, but other configurations are also contemplated. In particular, even though expressions such as “in one embodiment”, “in another embodiment”, “in embodiments”, or the like are used herein, these phrases are meant to generally reference embodiment possibilities, and are not intended to limit the invention to particular embodiment configurations. As used herein, these terms may reference the same or different embodiments that are combinable into other embodiments. As a rule, any embodiment referenced herein is freely combinable with any one or more of the other embodiments referenced herein, and any number of features of different embodiments are combinable with one another, unless indicated otherwise.
Although the invention has been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be used in alternative embodiments to those described, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.
This application is based on, claims benefit of, and claims priority to U.S. Application No. 63/236,652 filed on Aug. 24, 2021, which is hereby incorporated by reference herein in its entirety for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2022/041340 | 8/24/2022 | WO |
Number | Date | Country | |
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63236652 | Aug 2021 | US |