US5474558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Procedure and system for spinal pedicle screw insertion
Assignee: SDGI Holdings Inc
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Filing: 1994-07-18
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Granted: 1995-12-12
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Expires: 2014-07-18
Abstract
Abstract Pedicle screws are inserted in spinal vertebrae in a manner to reduce the likelihood of nerve damage caused by improper screw placement. A screw opening is started in part of a skeletal region, e.g., a pedicle of a lumbar vertebra and an electric potential of a certain magnitude is applied to the inner surface of the opening while the patient is observed for nervous reactions such as leg twitching. The opening continues to be formed while the electric potential is applied until a desired hole depth is obtained in the absence of nervous reaction to the potential. The direction in which the screw opening is being formed is changed to a direction other than the last direction, after observing patient reactions to the electric potential when the screw opening was being formed in the last direction. A system for carrying out the procedure includes a tool handle and a probe member extending from the handle with a tip for working an opening in bone tissue. An electrical stimulator in the form of a self-contained nerve stimulator unit, or circuitry provided inside the tool handle, produces an electric potential at a selected level. The potential is applied to the tip of the probe member while the tool handle is manipulated and the tip is directed toward the bone tissue.
Inventors
- 👤 Seth L. Neubardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:26
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8875; A61B17/16; A61B17/1613; A61B17/1626; A61B17/1655; A61B17/1662; A61B17/1671; A61B17/17; A61B17/1703; A61B17/68; A61B17/70; A61B2017/00017; A61B2017/00022; A61B2017/00039
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
184 words
A surgical tool system for forming and working openings in a patient's bone having nerve tissue in the region of the openings to be formed, comprising: an elongate tool handle shaped to be held and twisted by a surgeon when forming openings in the patient's bone; a first probe member arranged to extend from an end of the tool handle and including a probe shaft; electrically conductive tip means at a free end of said probe shaft, said tip means being suitably shaped and having sufficient strength for forming an opening in a selected bone when urged against the bone by said tool handle; and stimulator circuit means coupled to the tip means on said probe shaft for producing an electric stimulation potential of at least a first level at said tip means when the tip means is forming said opening; wherein said first level of the electric stimulation potential corresponds to a potential at which a predetermined nerve response is induced in the patient when said tip means is in proximity to said nerve tissue while forming said opening in the patient's bone.
Claim 2
Dependent Claim
184 words
A surgical tool system for forming and working openings in a patient's bone having nerve tissue in the region of the openings to be formed, comprising: an elongate tool handle shaped to be held and twisted by a surgeon when forming openings in the patient's bone; a first probe member arranged to extend from an end of the tool handle and including a probe shaft; electrically conductive tip means at a free end of said probe shaft, said tip means being suitably shaped and having sufficient strength for forming an opening in a selected bone when urged against the bone by said tool handle; and stimulator circuit means coupled to the tip means on said probe shaft for producing an electric stimulation potential of at least a first level at said tip means when the tip means is forming said opening; wherein said first level of the electric stimulation potential corresponds to a potential at which a predetermined nerve response is induced in the patient when said tip means is in proximity to said nerve tissue while forming said opening in the patient's bone.
Claim 3
Dependent Claim
38 words
A surgical tool system according to claim 1, wherein said stimulator circuit means includes means for selecting one of a number of different levels for the electric stimulation potential applied at said tip, means including said first level.
Claim 4
Dependent Claim
73 words
A surgical tool system according to claim 2, wherein said stimulator circuit means includes means for producing an electric stimulation potential of a second level at said tip means in accordance with operation of said selecting means, said second level corresponding to a potential at which a predetermined nerve response is induced in the patient when said tip means is in contact with a nerve or a nerve root in the patient's bone.
Claim 5
Dependent Claim
46 words
A surgical tool system according to claim 3, wherein said stimulator circuit means includes means for producing an electric stimulation potential of a third level at said tip means in accordance with operation of said selecting means, said third level being greater than said first level.
Claim 6
Dependent Claim
30 words
A surgical tool system according to claim 2, wherein said selecting means includes a number of switch button means each corresponding to a different level of said electric stimulation potential.
Claim 7
Dependent Claim
45 words
A surgical tool system according to claim 5, including means coupled to each of said switch button means for disabling the operation of said stimulator circuit means from producing said electric stimulation potential when more than one of the switch button means are operated simultaneously.
Claim 8
Dependent Claim
42 words
A surgical tool system according to claim 1, including socket means at one end of said tool handle for accepting an attachment end of said probe member, and for enabling the probe member to be detached from the tool handle when desired.
Claim 9
Dependent Claim
54 words
A surgical tool system according to claim 7, wherein said socket means includes ratchet means for enabling a probe member accepted in the socket means to be turned operatively by the tool handle in only one sense of rotation when the tip of the probe member is forming an opening in the patient's bone.
Claim 10
Dependent Claim
40 words
A surgical tool system according to claim 7, comprising a set of at least two different probe members including said first probe member, wherein each probe member has an attachment end to fit the socket means of the tool handle.
Claim 11
Dependent Claim
27 words
A surgical tool system according to claim 9, including a second probe member having a head end opposite its attachment end for driving a pedicle screw member.
Claim 12
Dependent Claim
19 words
A surgical tool system according to claim 1, wherein said stimulator circuit means is contained in said tool handle.
Claim 13
Dependent Claim
213 words
A surgical tool system for use in forming and working openings in a patient's bone having nerve tissue in the region of the openings to be formed, in combination with an elongate probe member having a conductive shaft, a handle at one end of the shaft, and a working part at the other end of the shaft to be placed in electrical contact with said bone when or after said openings are formed; said tool system comprising: a stimulator circuit body including sleeve means for fitting on the shaft of said probe member in electrical conducting relation; stimulator circuit means contained in said body and coupled to said sleeve means, for producing an electric stimulation potential of at least a first level along the shaft of said probe member when the stimulator circuit body is fitted on the shaft of the probe member, said shaft conducting said electric stimulation potential to the working part while the working part of the probe member is forming said openings; wherein said first level of the electric stimulation potential corresponds to a potential at which a predetermined nerve response is induced in the patient when said working part of the probe member is in proximity to said nerve tissue while forming said openings in the patient's bone.
Claim 14
Dependent Claim
213 words
A surgical tool system for use in forming and working openings in a patient's bone having nerve tissue in the region of the openings to be formed, in combination with an elongate probe member having a conductive shaft, a handle at one end of the shaft, and a working part at the other end of the shaft to be placed in electrical contact with said bone when or after said openings are formed; said tool system comprising: a stimulator circuit body including sleeve means for fitting on the shaft of said probe member in electrical conducting relation; stimulator circuit means contained in said body and coupled to said sleeve means, for producing an electric stimulation potential of at least a first level along the shaft of said probe member when the stimulator circuit body is fitted on the shaft of the probe member, said shaft conducting said electric stimulation potential to the working part while the working part of the probe member is forming said openings; wherein said first level of the electric stimulation potential corresponds to a potential at which a predetermined nerve response is induced in the patient when said working part of the probe member is in proximity to said nerve tissue while forming said openings in the patient's bone.
Claim 15
Dependent Claim
38 words
A surgical tool system according to claim 12, wherein said stimulator circuit means includes means for selecting one of a number of different levels for the electric stimulation potential applied at said working part, including said first level.
Claim 16
Dependent Claim
73 words
A surgical tool system according to claim 13, wherein said stimulator circuit means includes means for producing an electric stimulation potential of a second level at said working part in accordance with operation of said selecting means, said second level corresponding to a potential at which a predetermined nerve response is induced in the patient when said working part is in contact with a nerve or a nerve root in the patient's bone.
Claim 17
Dependent Claim
46 words
A surgical tool system according to claim 14, wherein said stimulator circuit means includes means for producing an electric stimulation potential of a third level at said working part in accordance with operation of said selecting means, said third level being greater than said first level.
Claim 18
Dependent Claim
30 words
A surgical tool system according to claim 16, wherein said selecting means includes a number of switch button means each corresponding to a different level of said electric stimulation potential.
Claim 19
Dependent Claim
45 words
A surgical tool system according to claim 16, including means coupled to each of said switch button means for disabling the operation of said stimulator circuit means from producing said electric stimulation potential when more than one of the switch button means are operated simultaneously.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-11 | 1999-06-12 | 1999-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-11 | 2003-06-12 | 2003-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-11 | 2007-06-12 | 2007-12-12 | $7700.00 | Window Closed / Lapsed |