Methods for correcting spinal deformities
The present application discloses methods for treating spinal deformities. One embodiment includes inserting an elongated corrective member into the patient. During insertion, the corrective member is operatively attached to a first vertebral member that applies a first corrective force to correct a first vertebral member alignment. The corrective member is further inserted into the patient and subsequently operatively attached to a second vertebral member that applies a second corrective force to correct a second vertebral member alignment. The corrective member is further inserted and subsequently operatively attached to a third vertebral member that applies a third corrective force to correct a third vertebral member alignment. The embodiment may further include operatively attaching the corrective member to additional vertebral members to correct further misalignment. In one embodiment, a second member is attached to the vertebral members after they have been aligned to maintain the alignment.
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The present application is directed to methods for correcting spinal deformities and, more particularly, to methods of applying a corrective force to one or more of the vertebral members.
The spine is divided into four regions comprising the cervical, thoracic, lumbar, and sacrococcygeal regions. The cervical region includes the top seven vertebral members identified as C1-C7. The thoracic region includes the next twelve vertebral members identified as T1-T12. The lumbar region includes five vertebral members L1-L5. The sacrococcygeal region includes nine fused vertebral members that form the sacrum and the coccyx. The vertebral members of the spine are aligned in a curved configuration that includes a cervical curve, thoracic curve, and lumbosacral curve. Intervertebral discs are positioned between the vertebral members and permit flexion, extension, lateral bending, and rotation.
Various deformities may affect the normal alignment and curvature of the vertebral members. Scoliosis is one example of a deformity of the spine in the coronal plane, in the form of an abnormal curvature. While a normal spine presents essentially a straight line in the coronal plane, a scoliotic spine can present various lateral curvatures in the coronal plane. The types of scoliotic deformities include thoracic, thoracolumbar, lumbar or can constitute a double curve in both the thoracic and lumbar regions. Scoliosis may also include abnormal translation and rotation in the axial and sagittal planes. Schuermann's kyphosis is another example of a spinal deformity that affects the normal alignment of the vertebral members in one or more planes. Further, a fracture of one or more of the vertebral members may cause misalignment along the spine. The term “deformity” and the like is used herein to describe the various types of spinal misalignment.
SUMMARYThe present application discloses methods for treating spinal deformities. One embodiment of a method includes inserting a longitudinal corrective member into the patient. During insertion, the corrective member is operatively attached to a first vertebral member that applies a first corrective force to correct a first vertebral member alignment. The corrective member is further inserted into the patient and subsequently operatively attached to a second vertebral member that applies a second corrective force to correct a second vertebral member alignment. The corrective member is further inserted and subsequently operatively attached to a third vertebral member that applies a third corrective force to correct a third vertebral member alignment. The embodiment may further include operatively attaching the corrective member to additional vertebral members to correct further misalignment. In one embodiment, a second member is attached to the vertebral members after they have been aligned to maintain the alignment.
The present application is directed to methods for correcting a spinal deformity. One embodiment of the method includes initially attaching anchors to the vertebral members positioned along a length of a deformed spine. The anchors are positioned along the deformed spine in a first lateral row. An elongated corrective member is than inserted into the patient and through each of the anchors sequentially along the deformed spine. The corrective member is manipulated sequentially to move the vertebral members into alignment. The shape of the corrective member and the movement to fit within the anchors produces a corrective force. This movement sequentially translates the vertebral members at the various spinal levels to treat the spinal deformity. In one embodiment, a second member is inserted into the patient through a second lateral row of anchors. The second rod is secured to the anchors thus causing the vertebral members to remain in the aligned position.
Correction of the spinal deformity initially requires placing anchors within the vertebral members 90.
In one embodiment, a pair of anchors 20 is positioned within each of the vertebral members 90 along the deformed section of the spine. In another embodiment, a single anchor 20 is positioned within one or more of the vertebral members 90. The single anchor 20 is positioned within either pedicle location.
An extender 30 may be connected to one or more of the anchors 20 along one of the rows A, B. The extenders 30 may function both as a reduction device, as well as a translation and rotation device as will be described in detail below.
The distal end 31 includes a pair of opposing legs 39 that connect to the head of the anchor 20. The legs 39 form an opening that aligns with the receiver 23 to form a window 36. The distal end 31 may further include threads adapted for threading engagement with a corresponding portion of the bone anchor 20, or to an element coupled to one or more bone anchors 20. The threads couple the extender 30 to the anchor 20. In a specific embodiment, the threads are engaged with a threaded projection associated with a bone screw, such as, for example, an externally threaded nut used with a pedicle screw. One embodiment of a pedicle screw is used in association with the CD-Horizon Legacy Spinal System manufactured by Medtronic Sofamor Danek of Memphis, Tenn.
A sliding member 34 is movably positioned on the exterior of the tubular element 33 and located in proximity to the distal end 31. Sliding element 34 includes contact edges 35 that form an upper edge of the window 36. The proximal end 32 includes a fitting 38 that is operatively connected to the sliding element 34. Rotation of the fitting 38 in first and second directions causes the sliding element 34 to move downward and upward respectively along the tubular element 33. One example of an extender 30 is the Sextant Perc Trauma Extender available from Medtronic Sofamor Danek of Memphis, Tenn.
A corrective rod 50 is then sequentially inserted along the spine and attached to the anchors 20 at the various spinal levels. The corrective rod 50 may be inserted in a top-to-bottom direction or a bottom-to-top direction.
The corrective rod 50 includes a pre-bent shape to apply specific corrective forces to the individual vertebral members 90. In one embodiment, the shape of the corrective rod 50 is determined by studying the flexibility of the spinal deformity prior to the procedure. The shape of the rod 50 corresponds to the needed displacement to translate and/or rotate the vertebral members 90 into alignment. A greater amount of bend at the tip 51 allows for a greater amount of translation and rotation of the vertebral members 90. Rod 50 may be bent in one, two, or three dimensions depending on the amount of correction needed for the vertebral members 90 in the coronal, sagittal, and axial planes.
The curvature of the rod 50 may be more pronounced within a first plane than in a second plane.
The corrective rod 50 may be attached to an inserter 60 for insertion and positioning within the patient. As illustrated in
The corrective rod 50 is inserted into the patient P as illustrated in
This process continues as the tip 51 is moved sequentially through a third window formed at the third extender 30C, and through a fourth window formed at the fourth extender 30D. The insertion of the tip 51 into each window and the accompanying rotation of the corrective rod 50 applies a corrective force to that vertebral member 90 to translate and/or rotate the vertebral member 90 into alignment.
In one embodiment as illustrated in
In one embodiment, the windows 36 formed at the various anchors 20 by the extenders 30 are in the open orientation prior to and during insertion of the corrective rod 50. In one embodiment, the window 36 is moved to the closed orientation once the tip 51 has moved through the window. The reduction includes rotating the fitting 38 on the proximal end 32 of the extender 30. As best illustrated in
In one embodiment, the corrective rod 50 is rotated at each spinal level as part of the insertion process of moving the tip 51 through each anchor 20. As illustrated in
In another embodiment, the corrective rod 50 remains substantially within the same rotational position during insertion into the patient. Once the rod 50 is positioned through each of the anchors 20, the rod 50 is rotated to apply the additional corrective force to the vertebral members 90 due to the curvature of the rod 50.
The corrective rod 50 is next inserted through a third window formed by anchor and extender 20/30C attached to a third vertebral member 90C as illustrated in
The corrective rod 50 is than moved in a manner to insert the tip 51 through the fourth window of anchor/extender 20/30D attached to the fourth vertebral member 90D as illustrated in
The extenders 30 attached to the anchors 20 are also used during the sequential process to apply forces to the vertebral members 90. Once the corrective rod is inserted through the first two windows formed by anchors/extenders 20/30A and 20/30B as illustrated in
The windows may be closed or opened sequentially at each vertebral member 90 prior to rotation of the corrective rod 50. As illustrated in
The corrective rod 50 aligns the vertebral members 90 as schematically illustrated in
With the corrective rod 50 remaining within one of the anchor rows A, B, a second rod 60 is inserted within the second row. In one embodiment, prior to insertion of the second rod 60, extenders 30 are attached to the anchors 20 of the second row. In one embodiment, attachment of the extenders 30 to the second row of anchors 20 may occur prior to insertion of the corrective rod 50. In another embodiment, the extenders 30 are attached after the corrective rod 50 has been inserted and alignment of the vertebral members 90.
The second rod 60 maintains the vertebral members 90 within their new alignment. The process of inserting the second rod 60 may be similar to insertion of the corrective rod 50. The surgeon percutaneously inserts the second rod 60 into the patient and moves the second rod 60 through each of the anchors 20. For anchors 20 with associated extenders 30, the windows 36 are reduced in size towards the closed orientation after insertion of the second rod 60.
Once the second rod 60 is positioned, set screws may be attached to the anchors 20 to maintain the position of the rod 60. In anchors 20 with extenders 30, the set screws may be inserted through the interior of the extenders 30. The set screws engage with threads on the anchors 20 and maintain the second rod 60 attached to the anchors 20. In one embodiment, the set screws may include threads that engage with the head portions of the bone anchors 20 via a driving tool to maintain the rod 60 in engagement with the anchors 20. In one embodiment, a driving tool is inserted through the interior of the extenders 30. The tool includes a drive shaft including a distal end portion that is positioned within a tool receiving recess in the set screw, and a handle for imparting rotational force onto the drive shaft.
In one embodiment, the corrective rod 50 remains within the patient after the surgical procedure. The corrective rod 50 maintains the alignment of the vertebral members 90.
In another embodiment, once the second rod 60 is attached along one anchor row, the corrective rod 50 may be removed. Removal may initially require one or more of the windows 36 to be moved towards the open orientation. Removal requires the surgeon to manipulate the handle 62 and pull the corrective rod 50 from each anchor 20 and from the patient P. In one embodiment, a third rod 70 is then inserted to replace the corrective rod 50. Third rod 70 is shaped to maintain the vertebral members 90 in proper alignment. The insertion and attachment method is similar to that described above with reference to the second rod 60.
In one embodiment as described above, the corrective rod 50 is rotated after initial insertion to provide an additional amount of corrective force to be applied to the vertebral members 90. In another embodiment, threading the corrective rod 50 through the windows 36 provides an adequate amount of corrective force and aligns the vertebral members 90. In this embodiment, the corrective rod 50 is not rotated to a second rotational position.
In the embodiment described above, extenders 30 are attached to one or more of the anchors 20. The extenders 30 may be attached to each of the anchors 20 along one or both anchor rows A, B, or along less than each anchor 20. In one embodiment, no extenders 30 are attached to the anchors 20 and the one or more rods are inserted directly into the receivers 23 in the anchors 20.
In the embodiments of
In one embodiment, rods 60, 70 are attached to the vertebral members 90 to maintain the alignment. Various other members may be used to maintain the alignment of the vertebral members 90. The members may include but are not limited to a plate, bar, cable, tether, or other suitable elongate implant capable of maintaining the vertebral members 90 in the corrected alignment.
In one embodiment, the rods 50, 60, 70 are formed of a biocompatible material, such as, for example, stainless steel or titanium. However, other materials are also contemplated, including, for example, titanium alloys, metallic alloys such as chrome-cobalt, polymer based materials such as PEEK, composite materials, or combinations thereof. In one embodiment, one or more of rods 50, 60, 70 include an injectable construction that is inserted into the patient and afterwards filled with a hardening polymer.
Rods 60, 70 may be substantially straight within the plane illustrated in
In the embodiment described above, the extenders 30 include sliding members 34 to adjust the size of the windows 36. In another embodiment, extenders 30 are cylindrical tubes that do not include sliding members 34. A distal end of the tubes may be threaded to engage with the anchors 20, and the interior be substantially open to insert a set screw.
The devices and methods may be used to treat various abnormal spinal curvatures such as scoliosis. The devices and methods may also be used to treat other spinal deformities including kyphotic deformities such as Scheurmann's kyphosis, fractures, congenital abnormalities, degenerative deformities, metabolic deformities, deformities caused by tumors, infections, trauma, and other abnormal spinal curvatures.
In one embodiment, the devices and methods are configured to reposition and/or realign the vertebral members 90 along one or more spatial planes toward their normal physiological position and orientation. The spinal deformity is reduced systematically in all three spatial planes of the spine, thereby tending to reduce surgical times and provide improved results. In one embodiment, the devices and methods provide three-dimensional reduction of a spinal deformity via a posterior surgical approach. However, it should be understood that other surgical approaches may be used, including, a lateral approach, an anterior approach, a posterolateral approach, an anterolateral approach, or any other surgical approach.
The anchors 20 described above are some embodiments that may be used in the present application. Other examples include spinal hooks configured for engagement about a portion of a vertebral member 90, bolts, pins, nails, clamps, staples and/or other types of bone anchor devices capable of being anchored in or to vertebral member 90. In one embodiment, anchors 20 include fixed angle screws.
In still other embodiments, bone anchors may allow the head portion to be selectively pivoted or rotated relative to the threaded shank portion along multiple planes or about multiple axes. In one such embodiment, the head portion includes a receptacle for receiving a spherical-shaped portion of a threaded shank therein to allow the head portion to pivot or rotate relative to the threaded shank portion. A locking member or crown may be compressed against the spherical-shaped portion via a set screw or another type of fastener to lock the head portion at a select angular orientation relative to the threaded shank portion. The use of multi-axial bone anchors may be beneficial for use in the lower lumbar region of the spinal, and particularly below the L4 vertebral member, where lordotic angles tend to be relatively high compared to other regions of the spinal column. Alternatively, in regions of the spine exhibiting relatively high intervertebral angles, the anchors 20 may include a fixed angle.
In one embodiment, the treatment of the deformity is performed percutaneously. In other embodiments, the treatment is performed with an open approach, semi-open approach, or a muscle-splitting approach.
Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc and are also not intended to be limiting. Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
Claims
1. A method of treating a patient with a spinal deformity comprising the steps of:
- inserting an elongated corrective member into the patient;
- moving the corrective member through a first anchor attached to a first vertebral member;
- further inserting the corrective member into the patient and moving the corrective member through a second anchor attached to a second vertebral member and applying a first corrective force to align the second vertebral member with the first vertebral member; and
- further inserting the corrective member into the patient and moving the corrective member through a third anchor attached to a third vertebral member and applying a second corrective force to align the third vertebral member with the first and second vertebral members.
2. The method of claim 1, further comprising attaching the anchors at a common position to each of the first, second, and third vertebral members prior to inserting the corrective member.
3. The method of claim 1, wherein the steps of moving the correcting member through the second and third anchors comprises laterally moving the corrective member and rotating the corrective member within the patient.
4. The method of claim 1, wherein the step of moving the corrective member through the second anchor comprises moving the corrective member through a window formed between the second anchor and an extender.
5. The method of claim 4, further comprising reducing a size of the window to apply the first corrective force to the second vertebral member.
6. The method of claim 1, wherein the step of applying the first corrective force to align the second vertebral member with the first vertebral member causes translation and rotation of the second vertebral member.
7. The method of claim 1, further comprising inserting a second member into the patient after aligning the vertebral members and attaching the second member to the vertebral members to maintain the alignment.
8. The method of claim 1, further comprising removing the corrective member from the patient after aligning the vertebral members.
9. The method of claim 1, wherein the step of inserting the elongated corrective member into the patient is performed percutaneously.
10. A method of treating a patient with a spinal deformity comprising the steps of:
- inserting an elongated corrective member into the patient;
- operatively attaching the corrective member to a first vertebral member and applying a first corrective force to correct a first vertebral member alignment;
- subsequently operatively attaching the corrective member to a second vertebral member and applying a second corrective force to correct a second vertebral member alignment; and
- subsequently operatively attaching the corrective member to a third vertebral member and applying a third corrective force to correct a third vertebral member alignment.
11. The method of claim 10, wherein the step of correcting the first, second, and third vertebral member alignment includes applying a rotational force to at least one of the vertebral members.
12. The method of claim 10, wherein the step of correcting the first, second, and third vertebral member alignment includes applying a translational force to at least one of the vertebral members.
13. The method of claim 10, wherein the step of percutaneously inserting the corrective member into the patient comprises rotating the corrective member.
14. The method of claim 10, wherein the step of percutaneously inserting the corrective member into the patient comprises laterally moving the corrective member.
15. The method of claim 10, further including attaching a second member to the vertebral members after applying the third corrective force to correct the third vertebral member alignment.
16. The method of claim 10, further comprising attaching an anchor to each of the vertebral members prior to percutaneously inserting the corrective member.
17. A method of treating a patient with a spinal deformity comprising the steps of:
- inserting an elonated corrective member into the patient; and
- sequentially attaching the corrective member to a plurality of vertebral members forming a spinal segment and aligning the vertebral members by applying a different corrective force to each of the vertebral members.
18. The method of claim 17, further comprising rotating at least one of the plurality of vertebral members.
19. A method of treating a patient with a spinal deformity comprising the steps of:
- inserting an elongated corrective member into the patient;
- applying a first corrective force to a first vertebral member by moving the corrective member through a first anchor attached to the first vertebral member;
- applying a second corrective force to a second vertebral member by moving the corrective member through a second anchor attached to the second vertebral member;
- applying a third corrective force to a third vertebral member by moving the corrective member through a third anchor attached to the third vertebral member;
- after applying the third corrective force, inserting a second member into the patient and attaching the second member to each of the vertebral members to maintain a corrected alignment of the vertebral members.
20. The method of claim 19, further comprising removing the corrective member from the patient after attaching the second member to each of the vertebral members.
21. The method of claim 19, further comprising moving the corrective member through a window formed between the first anchor and an extender attached to the first anchor.
22. A method of treating a patient with a spinal deformity comprising the steps of:
- inserting an elongated corrective member into the patient;
- applying a first corrective force at a first spinal level by inserting the corrective rod a first amount and moving the corrective member along a first spinal segment;
- applying a second corrective force at a second spinal level by inserting the corrective rod a second amount and moving the corrective member along a second spinal segment; and
- applying a third corrective force at a third spinal level by inserting the corrective rod a third amount and moving the corrective member along a third spinal segment;
- wherein each of the first, second, and third corrective forces are different.
23. The method of claim 22, further comprising attaching the corrective rod to at least one vertebral member within each of the first, second, and third spinal segments.
Type: Application
Filed: Apr 25, 2007
Publication Date: Oct 30, 2008
Applicant: Warsaw Orthopedic, Inc. (Warsaw, IN)
Inventors: Mark Benedict Dekutoski (Rochester, MN), John Durward Pond (Germantown, TN)
Application Number: 11/739,919
International Classification: A61B 17/70 (20060101);