METHODS FOR CORRECTING SPINAL DEFORMITIES
The present application is directed to devices and methods for correcting a spinal deformity. A spacer is positioned between processes that extend outward from a pair of vertebral members. A force applicator is operatively connected to apply a force to the vertebral members. The spacer then acts as a fulcrum with the force causing the vertebral members to pivot about the spacer and become aligned in a more desired orientation to eliminate or reduce the deformity.
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The present application is directed to methods for correcting spinal deformities and, more particularly, to methods that apply 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. Schuermann's kyphosis is another example of a spinal deformity that affects the normal alignment of the vertebral members.
SUMMARYThe present application discloses methods for treating a spinal deformity. One method includes inserting a spacer between adjacent first and second vertebral members. A force applicator is then operatively connected to the vertebral members to apply a corrective force. The positioning of the spacer and the force applicator may vary depending upon the context of use. The applicator applies a force that causes the vertebral members to pivot about the spacer and become aligned to reduce the spinal deformity.
The present application is directed to methods for correcting a spinal deformity.
Spacer 30 also acts as a positioning device to reduce the load placed onto specific areas of the vertebral members 90. Prior art methods have included tethering that place an abnormally large load on the facet joints. This may cause the facet joints to experience excessive wear resulting in damage to the vertebral members 90, and/or pain to the patient. Spacer 30 absorbs all or a part of the load to reduce and/or eliminate wear on the facet joints and pain to the patient.
Spacer 30 may include a variety of shapes and sizes.
The spacer 30 may be formed for a variety of biocompatible polymeric materials, including elastic materials, such as plastics, metals, elastomeric materials, hydrogels or other hydrophilic-polymers, or composites thereof. The nature of the materials employed to form the spacer 30 may be selected to exhibit a sufficient stiffness to space apart the spinous processes 92a. The term stiffness is used to refer to the resistance of an elastic body to deflection by an applied force.
The spacer 30 may also be fully or partially constructed from bio-absorbable material. Bio-absorbable material provides the positioning and/or stiffness functions for a limited time after the spacer 30 is implanted and is then eventually absorbed by the body. In one embodiment, the bio-absorbable material is gradually absorbed by the body. During this initial period, the body may heal to an extent that the spacer 30 is adequate to support the vertebral members 90 and/or the body is able to position the spacer 30. In one embodiment, the bio-absorbable material is replaced with tissue, such as fibrous tissue and fibrous scar tissue. The bio-absorbable material may be formed from a wide variety of natural or synthetic materials including fibrin, albumin, collagen, elastin, silk and other proteins, polyethylene oxide, cyanoacrylate, polylactic acid, polyester, polyglycolic acid, polypropylene fumarate, tyrosine-based polycarbonate and combinations thereof. Other suitable materials include demineralized bone matrix. In one embodiment, bio-absorbable material may be a woven fabric.
Various embodiments of spacers 30 are disclosed in U.S. patent application Ser. Nos. 11/341,233 and 11/341,200 each filed Jan. 27, 2006 and each entitled “Interspinous Devices and Methods of Use”. These applications are hereby incorporated by reference. Another embodiment of a spacer is the DIAM Spinal Stabilization System available from Medtronic Sofamor Danek of Memphis, Tenn., also hereby incorporated by reference.
In one embodiment, the force applicator 40 applies a compressive force to the convex side 90b of the vertebral members 90.
Various types of tethers 42 may be used to apply the force.
In some embodiments, the tether 42 is constrained to the anchors 41. Other embodiments may include the tether 42 being unconstrained or semi-constrained connections. Still other embodiments may include connections that are combinations of the above. An example of a semi-constrained connection is a ball joint that allows at least some range of articulation of the construct relative to the anchor, or float within a neutral zone. Examples of constrained or semi-constrained connections include a construct that is wrapped around, crimped, clamped or penetrated by a portion of the anchor or a set screw or cap engageable to the anchor. Such constrained connections fix the construct to the anchor so that there is no or minimal relative movement therebetween
Tether material can include but is not limited to polymers, such as polyester and polyethylene; superelastic metals, such as nitinol; shape memory alloy, such as nickel titanium; resorbable synthetic materials, such as suture material, metals, such as stainless steel and titanium; synthetic materials, allograft material; and bioelastomer material. U.S. Patent Application Publication 2003/0088251 discloses various types of anchors and tethers and is herein incorporated by reference.
The spacer 30 may be positioned at different locations relative to the vertebral members 90. In the embodiment of
Some embodiments include a single spacer 30. This usually occurs when the tether 42 extends between two adjacent vertebral members 90.
In the embodiment illustrated in
In one embodiment, a single force applicator 40 and spacer 30 are attached to a single level of the spine, such as at the apex of the deformity. Using
It should be understood that the spinal deformity depicted in
The devices and methods may be used to treat spinal deformities in the coronal plane, such as a scoliotic spine illustrated in
One embodiment includes accessing the spine from an anterior approach. Other applications contemplate other approaches, including posterior, postero-lateral, antero-lateral and lateral approaches to the spine, and accessing various regions of the spine, including the cervical, thoracic, lumbar and/or sacral regions.
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 force applicator 40 may apply a force to arrest or minimize growth of the convex side 90b of the vertebral members 90, or alternatively, to simply prevent further deformity of the spine. 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
1-30. (canceled)
31. A method for treating a spinal deformity, comprising the steps of:
- distracting adjacent vertebral bodies; and
- compressing the adjacent vertebral bodies.
32. A method as recited in claim 31, wherein the step of distracting the adjacent vertebral bodies comprises applying a distraction force by inserting a spacer between the adjacent vertebral bodies.
33. A method as recited in claim 32, further comprising pivoting the adjacent vertebral bodies and deforming the spacer.
34. A method as recited in claim 31, wherein the step of distracting the adjacent vertebral bodies comprises applying a distraction force by inserting a spacer between the adjacent vertebral bodies such that the spacer engages a transverse process of each of the adjacent vertebral bodies.
35. A method as recited in claim 31, wherein the step of compressing the adjacent vertebral bodies comprises applying a compression force by attaching a force applicator to an exterior of each of the adjacent vertebral bodies.
36. A method as recited in claim 35, wherein the exterior of each of the adjacent vertebral bodies is a posterior section of each of the adjacent vertebral bodies.
37. A method as recited in claim 35, wherein the step of attaching the force applicator to the exterior of each of the adjacent vertebral bodies comprises mounting an anchor in the exterior of each of the adjacent vertebral bodies, the force applicator being constrained to the anchors.
38. A method as recited in claim 37, wherein at least one of the anchors is resorbable.
39. A method as recited in claim 31, wherein:
- the step of distracting the adjacent vertebral bodies comprises applying a distraction force by inserting a spacer between the adjacent vertebral bodies such that the spacer engages a transverse process of each of the adjacent vertebral bodies;
- the step of compressing the adjacent vertebral bodies comprises applying a compression force by attaching a force applicator to an exterior of each of the adjacent vertebral bodies.
40. A method as recited in claim 39, wherein the step of distracting the adjacent vertebral bodies occurs at the same time as the step of compressing the adjacent vertebral bodies.
41. A method as recited in claim 39, wherein:
- the compression force causes the adjacent vertebral bodies to move about the spacer and treat the spinal deformity; and
- moving the adjacent vertebral bodies about the spacer causes the adjacent vertebral bodies to pivot and deform the spacer.
42. A method as recited in claim 39, wherein the compression force is applied to the transverse processes.
43. A method for treating a spinal deformity, comprising the steps of:
- distracting adjacent vertebral bodies; and
- compressing the adjacent vertebral bodies,
- wherein the step of distracting the adjacent vertebral bodies occurs at the same time as the step of compressing the adjacent vertebral bodies.
44. A method as recited in claim 43, wherein:
- the step of distracting the adjacent vertebral bodies comprises applying a distraction force by inserting a spacer between the adjacent vertebral bodies such that the spacer engages a transverse process of each of the adjacent vertebral bodies;
- the step of compressing the adjacent vertebral bodies comprises applying a compression force by attaching a force applicator to an exterior of each of the adjacent vertebral bodies; and
- the force applicator is spaced apart from the spacer.
45. A method as recited in claim 44, further comprising pivoting the adjacent vertebral bodies and deforming the spacer.
46. A method as recited in claim 44, wherein the compression force causes the adjacent vertebral bodies to move about the spacer and treat the spinal deformity.
47. A method for treating a spinal deformity, comprising the steps of:
- distracting adjacent vertebral bodies by application of a distraction force between processes of adjacent vertebral bodies; and
- compressing the adjacent vertebral bodies by application of a compression force on the processes of the adjacent vertebral bodies.
48. A method as recited in claim 47, wherein the processes of the adjacent vertebral bodies are transverse processes.
49. A method as recited in claim 47, wherein:
- the distraction force is created by inserting a spacer between the adjacent vertebral bodies such that the a transverse process of each of the adjacent vertebral bodies is disposed in a gap defined by arms of the spacer; and
- the compression force is created by attaching a force applicator to an exterior of a posterior section of each of the adjacent vertebral bodies by mounting an anchor into the exterior of each of the adjacent vertebral bodies.
50. A method as recited in claim 49, wherein:
- the step of distracting the adjacent vertebral bodies occurs at the same time as the step of compressing the adjacent vertebral bodies;
- the compression force causes the adjacent vertebral bodies to move about the spacer and treat the spinal deformity; and
- moving the adjacent vertebral bodies about the spacer causes the adjacent vertebral bodies to pivot and deform the spacer.
Type: Application
Filed: May 21, 2014
Publication Date: Sep 11, 2014
Applicant: Warsaw Orthopedic, Inc. (Warsaw, IN)
Inventor: Fred J. Molz, IV (Birmingham, AL)
Application Number: 14/283,931
International Classification: A61B 17/02 (20060101);