Rod reducer instruments and methods
Rod reducers for use in orthopedic surgery are disclosed that include a fastener engaging member and a reducing member coupled together by an actuator assembly. The fastener engaging member can be secured to a fastener engaged to bone or tissue of the patient. The actuator assembly moves the reducing member such that its distal end contacts a rod and moves it toward the fastener.
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This application is a reissue of U.S. Pat. No. 6,440,133 B1, issued on Aug. 27, 2002, which is hereby incorporated by reference, as if fully set forth herein. U.S. Pat. No. 6,440,133 B1 matured from U.S. application Ser. No. 09/898,626, filed Jul. 3, 2001.
FIELD OF THE INVENTIONThe present invention concerns surgical instrumentation for moving one part of a surgical implant into adjacent position or contact with another. In particular, the invention contemplates rod reducer instruments for use in placing or moving an orthopedic rod toward a bone fixation element.
BACKGROUND OF THE INVENTIONIn the field of orthopedic surgery, and particularly spinal surgery, it is well known to correct an injury, malformation, or other defect by use of an implanted rod affixed to the body part to be corrected. For example, rod systems have been developed for correcting the positioning of and stabilizing the spine, and for facilitating fusion at various levels of the spine. In one such system, the rod is disposed longitudinally along a length of the spine. The rod is preferably bent, either prior to or during surgery, to correspond to the normal curvature of the spine in the particular region being instrumented, or to such other curvature as the surgeon may deem appropriate to correct the defect. For example, the rod can be bent to form a normal kyphotic curvature for the thoracic region of the spine, or to form a normal lordotic curvature for the lumbar region. The rod is engaged to a number of fixation elements fixed to or engaged with the vertebrae along the segment of the spinal column.
A variety of fixation elements can be provided that are configured to engage the vertebrae. For instance, one such fixation element is a laminar hook, configured to engage a lamina of the vertebra. Another prevalent fixation element is a spinal screw which can be threaded into a pedicle or other portion of vertebral bone. Examples of such spinal screws are seen in U.S. Pat. No. 5,005,562 to Cotrel, the disclosure of which is incorporated herein by reference. An alternative type of fixation element is a multi-axial bone screw, such as that as disclosed in U.S. Pat. Nos. 5,797,911 and 5,879,350 to Sherman et al., each of which is also incorporated herein by reference in its entirety. Further types of bone screws, hooks, bolts, or other fixation elements are known in the art.
In one typical spinal procedure, an elongated implant (e.g. a rod) is coupled to two or more fixation elements (e.g. bone screws) that are fixed to opposite sides of the spine or spinous processes. The bone screws are first threaded into a portion of several vertebral bodies, such as the pedicles of these vertebrae. The rod is coupled to the bone screws to provide corrective and stabilizing forces to the spine. Affixing a rod to a bone screw generally requires the rod to be in close adjacent position or in contact with the screw. For example, with respect to bone screws as disclosed in the Cotrel '562 patent and the Sherman '911 and '350 patents identified above, a rod and an implanted screw must be moved with respect to each other so that the rod occupies space within a channel or other opening in the screw. The rod is then coupled to the implanted bone screw using a set screw, plug or other appropriate fastener. The process of placing a rod within or adjacent to an implanted fixation element so that they can be coupled together is termed “reducing” the rod.
Rod reduction is commonly performed by a surgeon using his or her hands and/or rigid tools as pliers, levers or other instrumentation adaptable to create the necessary pushing and/or pulling forces on the implanted screw and rod. Such procedures generally require the surgeon to place the rod directly over the implanted fixation element, intersecting a longitudinal axis of the fixation element. Consequently, access to the rod and the implanted fixation element along that axis, i.e. directly above the opening in the fixation element into which the rod is to be placed, is necessary or at least highly desirable. However, such access can be difficult depending on such factors as the malformation to be corrected and the overall physiology of the patient, and can be very difficult in procedures in which surgical invasiveness is to be minimized, as a result of the small ports or incisions of such procedures. Additionally, with use of mono-axial screws, the physiology of the patient can require that the screw be placed at an angle such that the surgeon would have difficulty accessing and exerting force in the necessary orientation on the rod and/or fixation element. With multi-axial fixation devices, the orientation of an unsecured rod-receiving part of the fixation element can be even more varied with respect to the rod and/or the surgeon. Consequently, the surgeon is still frequently faced with the task of reducing a rod from an awkward angle.
Various attempts in the prior art have been made in providing rod reducing instruments, such as described in U.S. Pat. No. 6,036,692 to Burel et al.; U.S. Pat. No. 5,910,141 to Morrison et al.; and U.S. Pat. No. 5,720,751 to Jackson; each of which is incorporated herein by reference in its entirety. However, needs remain in the industry for rod reducing instruments that can be used efficiently, safely and securely in rod reduction procedures and for rod reduction instruments that can be used in both minimally invasive and open surgical approaches to the site of rod attachment.
SUMMARY OF THE INVENTIONThe present invention provides instrumentation for rod reduction during orthopedic surgery that are efficient and convenient to use. The instruments eliminate the need for direct application of manual force to a rod to position it in a desired location relative to a fastener. The instruments can also facilitate attachment of the rod to the fastener, and have application in both open surgical procedures and minimally invasive surgical procedures.
Aspects, objects, advantages, features, embodiments, and benefits of the present invention will be evident upon consideration of the following written description and the accompanying figures, which illustrate embodiments of the invention.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any such alterations and further modifications in the illustrated device, and any such further applications of the principles of the invention as illustrated therein, are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to
Rod reducer instrument 50 includes a fastener engaging member 80 and a reducing member 100 coupled together by an actuator assembly 51 such that reducing member 100 is movable proximally and distally with respect to fastener engaging member 80. Fastener engaging member 80 is engageable to fastener F and reducing member 100 is movable to contact rod R and push it toward fastener F. In the illustrated embodiment, reducing member 100 is slidably disposed about fastener engaging member 80, and rod R is captured in fastening engaging member 80 when reducing member 100 is in a retracted position as shown in
With further reference to
Body 84 also includes first and second flex arms 90 and 92. In the illustrated embodiment, flex arms 90 and 92 have slots 91 and 93 extending therebetween. Slot 91 includes a relieved portion 91a and slot 93 includes a relieved portion 93a to facilitate flexion of flex arms 90 and 92 away from one another as distal portion 88 is positioned over yoke Y of fastener F. In the illustrated embodiment, distal portion 88 includes prongs 94 and 96 through which slots 91 and 93 extend. Each prong 94, 96 includes a rod channel 94a, 96a in communication with slots 91, 93 and configured to receive rod R therein. Flex arms 90 and 92 can be apart in their natural state, so that they can be squeezed together by reducing member 100 contacting the enlarged distal portion 88 to hold a fastener F therein, and released to move apart from each other and release fastener F. Alternatively, flex arms 90, 92 can be together in their natural state, so that they can be forced apart by insertion of a fixation element or other application of force, and will naturally clamp on or around fastener F.
Prongs 94 and 96 are substantially identically configured, and therefore they will both be described by reference to prong 96 as shown in
It will be understood that fastener engaging member 80 need not include flex arms 90, 92, but rather be a formed from a substantially solid body having an appropriately-shaped socket distal end for engaging fastener F and including a rod channel which receives rod R. Such a solid body could also include spring-loaded protrusions that allow passage of the distal end over yoke Y until the protrusions engage in the corresponding indentations. Furthermore, such a distal end could include only a pair of protrusions on the inner wall oriented toward rod channels 94a, 94b and engage indentations or holes formed on corresponding locations of yoke Y of fastener F, such as shown in the aforementioned '911 patent. Other means for connecting fastener engaging member 80 to fastener F are also contemplated, including a snap rings, set screws, or an interference fit, to name a few.
Proximal end 87 of fastener engaging member 80 further includes a lateral extension 98 having a hole 98a formed therein. As shown in
Rod reducer instrument 50 further includes reducing member 100 positioned about fastener engaging member 80. Referring now to
Passage 102 can include distal portion 102a defined by an extension portion 104a of body 104. Passage 102 also includes a proximal portion 102b in communication with distal portion 102a and opening at proximal end 106. Distal portion 102a is larger in diameter than proximal portion 102b and is sized to receive enlarged distal portion 88 of fastener engaging member 80 therein. A lip 102c is defined between distal portion 102a and proximal portion 102b and contacts enlarged rim 88a to limit the distance of distal movement of reducing member 100 with respect to fastener engaging member 80. The length L2 of passage 102a and extension 104a of reducing member 100 can vary from 0 millimeters up to 20 millimeters or more, thus allowing the surgeon to select a rod reducer instrument 50 having an extension 104a/distal passage 102a of appropriate length for the distance of rod reduction beyond distal end 89 that is desired. It is further contemplated that proximal portion 102b can include a further inwardly stepped portion or other means for contacting or reducing the spacing between fastener engaging member 80 and reducing member 100 to limit the amount of wobble or play of reducing member 100 with respect to fastener engaging member 80.
In procedures using multiple fasteners F along the spine, yokes Y can have extended lengths from the head of fastener F that allows rod R to be spaced at various distances from each fastener F. The ability to select from rod reducer instruments having different extension lengths L2 enables the spacing between each fastener F and rod R in yoke Y to be controlled and varied, such as would be desirable in a spondylolisthesis reduction technique. After the desired rod position in the extended yoke Y is obtained, a set screw is placed through passage 82 and into yoke Y to maintain rod R at this desired position.
In another form, rod reducer instrument 50 has a passage 102 with a distal portion 102a that is sized to engage enlarged distal portion 88 of fastener engaging member 80. Distal end 88 contacts enlarged rim 88a to limit the amount of distal displacement of reducing member 100. Proximal portion 102b fits closely around fastener engaging member 80 to limit or eliminate wobble or play of reducing member 100 with respect to fastener engaging member 80. In order to adapt this form of rod reducer instrument 50 for spondylolisthesis procedures, an extension member 500 is provided as shown in
Actuator assembly 51 includes a first arm 52 and a second arm 54, and is operable to selectively move reducing member 100 proximally and distally along fastener engaging member 80 with longitudinal axes 86 and 116 substantially aligned. Contact between the distal ends 58, 59 of arms 52, 54 of actuator assembly 51 prevent reducing member 100 from being retracted too far proximally. As reducing member 100 is moved distally, its distal end 108 contacts rod R and moves it distally towards fastener F. The surgeon can then insert the set screw or cap through passage 82 of fastener engaging member 80 to secure rod R in yoke Y. Passage 82 can be sized and configured to closely fit with the driver used to install the set screw to ensure proper alignment between the set screw and the yoke. Reducing member 100 can be provided with slots 114, 115 that are alignable with slots 91, 93 of fastener engaging member 80. This allows the surgeon to visualize passage 82 and the internal portion of yoke Y during rod reduction and set screw placement to verify proper alignment and positioning. Extension member 500 could also be provided with slots 514 through its body 504 to allow such visualization when it is used.
First ear 110 can be provided with a female receptacle 111 into which one end of a first link 120 of actuator assembly 51 can be placed. Sirilarly, second ear 112 can be provided with a female receptacle 113 into which one end of a second link 122 of actuator assembly 51 can be placed. First and second links are identical, and will be described further with reference to first link 120 shown in
Second hole 128 of link 120 is pivotally connected to a first offset pivot arm 130 of actuator assembly 51 by pin 127, and the identical second hole of second link 122 is pivotally coupled to second offset pivot arm 140 of actuator assembly 51 by pin 129. Referring now to
Referring now to
As shown in
Referring now to
First arm 52 has a medially extending male connector 62 defining a hole 62a therethrough. Second arm 54 has a medially extending female connector 64 defining a receptacle (not shown) in communication with holes 64a. The receptacle of female connector 64 is sized to receive male connector 62, and a pin 65 extends through holes 64a and 62a to pivotally couple first arm 52 and second arm 54 to one another.
Rod reducer instrument 50 includes a locking mechanism that holds actuator assembly 51 in a closed position such as shown in
Proximal end 57 of second arm 54 further includes a tip 66 that is stepped down to a reduced thickness from that of second arm 54. Tip 66 includes a hole 66a formed therein and a finger 66b extending proximally therefrom and pointing laterally away from-first arm 52. Proximal end 56 of first arm 52 has a hole 60 formed in a medial side thereof into which ratchet bracket 68 (
Rod reducer instrument 50 further includes a leaf spring 72 extending between and engaged to the medial sides of first arm 52 and second arm 54 to provide a biasing force that normally biases actuator assembly 51 to an open position. Leaf spring 72 includes a first end 72a extending through ratchet bracket 68 and away from first arm 52 to contact an inclined end wall 70f of ratchet 70 to normally bias medial end 70g of ratchet 70 in the distal direction. When actuator assembly 51 is closed, first arm 52 is adjacent second arm 54 as shown in
To facilitate disengagement of ratchet 70 and finger 66b, a thumb release lever 74 is provided that is pivotally coupled to tip 66. Lever 74 has a hole 74a through which a pin may be placed to pivotally couple lever 74 to hole 66a of tip 66. Lever 74 includes a press member 74b and an opposite nub 74c. When arms 52, 54 are in their closed position as shown in
A method for using rod reducer instrument 50 will now be described. The surgeon has positioned fastener F into vertebra V1 and placed rod R in the proximity of yoke Y of fastener F. Rod reducer instrument 50 is in its normally biased open position of
With rod R in rod channels 94a, 96a and distal portion 88 secured to yoke Y, arms 52, 54 are moved towards one another against the bias of spring 72 until ratchet 70 engages finger 66b. As arms 52, 54 of actuator assembly 51 are moved toward one another, reducing member 100 moves distally along fastener engaging member 80 to push or reduce rod R into yoke Y a sufficient distance to allow attachment of a set screw or cap to yoke Y.
The distal movement of reducing member 100 is effected by distal ends 58, 59 of arms 52, 54, respectively, moving away from one another, which thereby pivots lateral offset pivot arms 130, 140 about fastener 99 so that proximal ends 134, 144 move away from one another and distal ends 132, 142 move towards one and distally, thereby pushing first and second links 120, 122 distally and effecting distal movement of reducing member 100 through the pivotal connection between ears 110, 112 and links 120, 122. Reducing member 100 also engages the enlarged distal portion 88 of fastener engaging member 80 thereby increasing the grip of prongs 94, 96 on yoke Y. The locked actuator assembly 51 holds rod R in its reduced position as the surgeon installs the set screw in yoke Y through passage 82 of fastener engaging member 80. The lateral offset provided by pivot arms 130, 140 facilitate surgeon access since arms 52, 54 are positioned away from the proximal end opening of fastener engaging member 80. Once the set screw is firmly seated in yoke Y, and preferably seated against rod R, lever 74 is pressed to release ratchet 70 from finger 66b so arms 52, 54 and reducing member 100 return to their open position of
Referring now to
Rod reducer instrument 150 further includes an adjustment mechanism 250 that allows fine control over movement of first arm 152 and second arm 154 relative to one another. Adjustment mechanism 250 include a thumb nut 252 coupled to a threaded shaft 254. Threaded shaft 254 is pivotally coupled to the medial side of first arm 152 and extends through a hole provided through second arm 154. Thumb nut 252 is positioned on the lateral side of second arm 154. In order to move first arm 152 and second arm 154 towards one another, thumb nut 252 can be threadingly advanced along threaded shaft 254 towards first arm 152. In order to move first arm 152 and second arm 154 away from one another, thumb nut 252 can be threadingly retracted along threaded shaft 254 away from first arm 152.
Referring to
Rod reducer instrument 350 includes a fastener engaging member 380 and a reducing member 400 coupled together by an actuator assembly 351 such that reducing member 400 is movable proximally and distally with respect to fastener engaging member 380. Fastener engaging member 380 is engageable to fastener F and reducing member 400 is movable to contact rod R and push it toward fastener F. In the illustrated embodiment, reducing member 400 is slidably disposed about fastener engaging member 380, and rod R is captured in fastening engaging member 380 when reducing member 400 is in a retracted position as shown in
With further reference to
Body 384 also includes first and second flex arms 390 and 392. In the illustrated embodiment, flex arms 390 and 392 have slots 391 and 393 extending therebetween. Slots 391 and 393 facilitate flexion of flex arms 390 and 392 away from one another as distal portion 388 is positioned over yoke Y of fastener F. In one embodiment, the distal end opening is tapered at angle B (
Flex arms 390 and 392 can each further include an inner profile sized and shaped to match the profile of the portion of yoke Y of fastener F that is positionable therein. Extending inwardly from flex arms 390 and 392 are protrusions 394 and 396, respectively. Protrusions 394 and 396 have a size, shape and depth that allows insertion into an indentation or hole formed in yoke Y of fastener F. For example, the multi-axial bone screw disclosed in U.S. Pat. No. 5,797,911 includes two diametrically opposed indentations in its exterior portion. However, it should be understood that flex arms 390 and 392 can be configured to fit other sizes, shapes or depths of indentation, or otherwise to connect to other bone fixation elements.
It will be understood that fastener engaging member 380 need not include flex arms 390, 392, but rather be formed from a substantially solid body having an appropriately-shaped socket distal end for engaging fastener F and including a rod channel to receive rod R. Such a solid body could also include spring-loaded protrusions that allow passage of the distal end over yoke Y until the protrusions engage in the corresponding indentations. Furthermore, such a distal end could include four protrusions as described above with respect to rod reducer instrument 50. Other means for connecting fastener engaging member 380 to fastener F are also contemplated, including snap rings, set screws, or an interference fit, to name a few.
Fastener engaging member 380 further includes a first ear 396 extending laterally therefrom having a hole 396a formed therethrough and a second ear 398 extending laterally therefrom having a hole 398a formed therethrough. As shown in
Referring now to
As reducing member 400 is moved distally, its distal end 408 contacts rod R and moves it distally towards fastener F. The surgeon can then insert the set screw or cap through passage 382 of fastener engaging member 380 to secure rod R in yoke Y. Passage 382 can be sized and configured to closely fit with the driver used to install the set screw to ensure proper alignment between the set screw and the yoke. To prevent reducing member 400 from being extended too far proximally, proximal end 387 of fastener engaging member 380 has a stop member 430, shown also in
As shown in
As shown in
Referring now to
Each of the arms 352, 354 has a medially extending female connector 362, 365 defining a hole 362a, 365a therethrough and a receptacle 362b, 365b in communication with hole 362a, 365a. Receptacles 362b, 365b are each sized to receive the proximal end of a respective one of the first and second links 420, 422. Pins 367, 369 extend through through-holes 362a, 365a to pivotally couple first arm 352 and second arm 354 to first link 420 and second link 422, respectively. While not required, rod reducer instrument 350 can include a locking mechanism (not shown) which holds actuator assembly 351 in its reduced position shown in
It is further contemplated that the rod reducer instruments of the present invention can be inserted through an access tube used in minimally invasive procedures to install fasteners F and perform other procedure on the spine. In
Rod reducer instrument 350 includes a laterally extending member 355, 357 extending from each of the arms 352, 354 to contact the proximal end of access tube 450 to limit the insertion depth of rod reducer instrument 350 therein. It should be understood that such laterally extending members could be provided with the other rod reducer instruments described herein, and located on other components thereof such as on fastener engaging members 80, 380.
A method for using rod reducer instrument 350 will now be described. The surgeon has positioned fastener F into vertebra V1 and placed rod R in close proximity to yoke Y of fastener F. Rod reducer instrument 350 is in its normally biased open position of
The rod reducer instruments of the present invention are preferably made of a sturdy biocompatible material such as stainless steel using standard fabrication techniques for medical grade instruments. However, other biocompatible materials are also contemplated.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
Claims
1. A surgical instrument for reducing a rod toward a bone fastener, comprising:
- a fastener engaging member extending between a proximal end and a distal end, a distal portion of said fastener engaging member being adapted to receive a portion of the rod therein and being further adapted to engage the bone fastener;
- a reducing member movably disposed about said fastener engaging member, said reducing member having a distal end and a longitudinal axis oriented in its direction of movement; and
- an actuator assembly pivotally coupled to said fastener engaging member and pivotally coupled to said reducing member, said actuator comprising a first arm and a second arm, wherein said actuator assembly is operable to move said reducing member distally with respect to said fastener engaging member when proximal ends of said first and second arms are biased together, whereby, with biasing together of said first and second arms, said distal end of said reducing member contacts the rod to move the rod distally, relative to said fastener engaging member, toward the bone fastener,
- wherein a plane along which said first and second arms move is offset from the longitudinal axis.
2. The instrument of claim 1, wherein said actuator assembly includes a lateral offset to position a proximal portion of said actuator assembly is offset away from a proximal end opening of a passage extending through said fastener engaging member.
3. The instrument of claim 1, wherein said actuator assembly includes a first arm is pivotally coupled to a said second arm.
4. The instrument of claim 3, wherein:
- said first arm includes a joint between a proximal end and a distal end of said first arm, said joint defining a proximal portion and a distal portion of said first arm;
- said second arm includes a joint between a proximal end and a distal end of said second arm, said joint defining a proximal portion and a distal portion of said second arm; and
- said proximal portion of said first arm and said proximal portion of said second arm are each pivotal about a respective one of said joints to orient said proximal portions transversely to said distal portions.
5. The instrument of claim 1, wherein said actuator assembly includes a locking mechanism to hold said reducing member in a reduced position.
6. The instrument of claim 1, wherein said actuator assembly is spring biased to a reducing member retracted position.
7. The instrument of claim 1, wherein said fastener engaging member includes a pair of flex arms extending proximally from said distal end thereof.
8. The instrument of claim 7, wherein said fastener engaging member includes a prong at the distal end of each of said flex arms, each of said prongs defining a channel for receiving the rod therein.
9. The instrument of claim 8, wherein said reducing member is positionable over at least a portion of said prongs.
10. The instrument of claim 7, wherein said fastener engaging member includes a pair of elongated slots extending between said flex arms opening at said distal end.
11. The instrument of claim 10, wherein said reducing member includes at least one slot through a sidewall thereof in communication with one of said elongated slots of said fastener engaging member.
12. The instrument of claim 1, wherein said fastener engaging member and said reducing member are reciprocally slidably coupled.
13. The instrument of claim 1, wherein said reducing member and said fastener engaging member each include a generally circular cross-section.
14. The instrument of claim 1, wherein:
- said fastener engaging member has a longitudinal axis extending proximally and distally therethrough; and
- said reducing member has a longitudinal axis extending proximally and distally therethrough, said longitudinal axis of said reducing member being generally positioned along said longitudinal axis of said fastener engaging member.
15. The instrument of claim 1, wherein said actuator assembly includes:
- a first link having a distal end pivotally coupled to a first side of said reducing member;
- a first pivot arm having a distal end pivotally coupled to a proximal end of said first link, said first pivot arm having a medially extending connector pivotally coupled to said fastener engaging member;
- a first arm having a distal end pivotally coupled to a proximal end of said first pivot arm, said first arm having a proximal portion extending proximally from a medially extending connector;
- a second link having a distal end pivotally coupled to a second side of said reducing member opposite said first side;
- a second pivot arm having a distal end pivotally coupled to a proximal end of said second link, said second pivot arm having a medially extending connector pivotally coupled to said medially extending connector of said first pivot arm and also pivotally coupled to said fastener engaging member; and
- a second arm having a medially extending connector pivotally coupled to said medially extending connector of said first arm, said second arm having a distal end pivotally coupled to a proximal end of said second pivot arm, said second arm further having a proximal portion extending proximally of said medially extending connector of said second arm.
16. The instrument of claim 1, wherein said actuator assembly includes:
- a first link having a distal end pivotally coupled to said reducing member;
- a first arm having a distal end pivotally coupled to said fastener engaging member, said first arm extending to a proximal end, said first arm further being pivotally coupled between said proximal and distal ends to a proximal end of said first link;
- a second link having a distal end pivotally coupled to said reducing member opposite said first link; and
- a second arm having a distal end pivotally coupled to said fastener engaging member opposite said first arm, said second arm extending to a proximal end and being pivotally coupled between said proximal and distal ends to a proximal end of said second link.
17. The instrument of claim 16, further comprising a stop member at said proximal end of said fastener engaging member to limit proximal movement of said reducing member.
18. A surgical instrument for reducing a rod toward a bone fastener, comprising:
- a fastener engaging member having a passage extending between a proximal end and a distal end, a distal portion of said fastener engaging member being adapted to receive a portion of the rod therein and being further adapted to engage the bone fastener, the passage having a longitudinal axis;
- a reducing member movably disposed with respect to said fastener engaging member, said reducing member having a distal end;
- an actuator assembly coupled between said fastener engaging member and said reducing member and, said actuator including a proximal portion, extending proximally of said reducing member and said fastener engaging member, a first arm and a second arm, wherein: said actuator assembly includes a lateral offset portion to locate said proximal portion of said actuator assembly away from a proximal end opening of said passage of said fastener engaging member; and said actuator assembly is operable to move said reducing member distally with respect to said fastener engaging member whereby said distal end of said reducing member contacts the rod to move the rod toward the bone fastener; and
- proximal ends of said first and second arms are biased together to move said reducing member distally relative to said fastener engaging member to move the rod toward the bone fastener; and
- a plane along which said first and second arms move is offset from the longitudinal axis.
19. The instrument of claim 18, wherein said reducing member is positioned about said fastener engaging member and slidable with respect thereto in response to operation of said actuator assembly.
20. The instrument of claim 19, wherein said distal end of said fastener engaging member includes a pair of prongs forming a rod passage.
21. The instrument of claim 20, wherein said reducing member and said distal end of said fastener engaging member are configured such that said reducing member exerts inward pressure on at least one of said prongs when said reducing member is positioned over said prongs.
22. The instrument of claim 18, wherein:
- said fastener engaging member has a longitudinal axis extending proximally and distally therethrough; and
- said reducing member has a longitudinal axis extending proximally and distally therethrough, said longitudinal axis of said reducing member being generally positioned along said longitudinal axis of said fastener engaging member.
23. The instrument of claim 18, wherein said actuator assembly includes:
- a first link having a distal end pivotally coupled to a first side of said reducing member;
- a first pivot arm having a distal end pivotally coupled to a proximal end of said first link, said first pivot arm having a medially extending connector pivotally coupled to said fastener engaging member;
- a first arm having a distal end pivotally coupled to a proximal end of said first pivot arm, said first arm having a medially extending connector;
- a second link having a distal end pivotally coupled to a second side of said reducing member opposite said first side;
- a second pivot arm having a distal end pivotally coupled to a proximal end of said second link, said second pivot arm having a medially extending connector pivotally coupled to said medially extending connector of said first pivot arm and also pivotally coupled to said fastener engaging member; and
- a second arm having a medially extending connector pivotally coupled to said medially extending connector of said first arm, said second arm having a distal end pivotally coupled to a proximal end of said second pivot arm.
24. The instrument of claim 18, wherein said actuator assembly includes:
- a first link having a distal end pivotally coupled to said reducing member;
- a first arm having a distal end pivotally coupled to said fastener engaging member, said first arm extending to a proximal end, said first arm further being pivotally coupled between said proximal and distal ends to a proximal end of said first link;
- a second link having a distal end pivotally coupled to said reducing member opposite said first link; and
- a second arm having a distal end pivotally coupled to said fastener engaging member opposite said first arm, said second arm extending to a proximal end and being pivotally coupled between said proximal and distal ends to a proximal end of said second link.
25. The instrument of claim 18, wherein said actuator assembly includes a first arm pivotally coupled to a second arm.
26. The instrument of claim 25, wherein:
- said first arm includes a joint between a proximal end and a distal end of said first arm, said joint defining a proximal portion and a distal portion of said first arm;
- said second arm includes a joint between a proximal end and a distal end of said second arm, said joint defining a proximal portion and a distal portion of said second arm; and
- said proximal portion of said first arm and said proximal portion of said second arm are each pivotal about a respective one of said joints to orient said proximal portions transversely to said distal portions.
27. The instrument of claim 25, wherein said first arm and said second arm are spring biased away from one another.
28. The instrument of claim 18, wherein said actuator assembly includes a locking mechanism to hold said reducing member in a reduced position.
29. The instrument of claim 18, wherein said fastener engaging member includes a pair of flex arms extending proximally from said distal end thereof.
30. The instrument of claim 29, wherein each of said flex arms includes a prong at a distal end thereof, each of said prongs defining a channel for receiving the rod therein.
31. The instrument of claim 30, wherein said fastener engaging member includes a pair of elongated slots extending between said flex arms to said distal end.
32. A surgical instrument for reducing a rod toward a bone fastener, comprising:
- a fastener engaging member extending between a proximal end and a distal end, a distal portion of said fastener engaging member being adapted to engage the bone fastener;
- a reducing member disposed about said fastener engaging member, said reducing member having a longitudinal axis oriented in its direction of movement;
- an actuator assembly coupled between said fastener engaging member and said reducing member and operable to move said reducing member about said fastener engaging member between a reduced position and a retracted position, wherein said actuator assembly includes: a first link having a distal end pivotally coupled to a first side of said reducing member; a first pivot arm having a distal end pivotally coupled to a proximal end of said first link, said first pivot arm having a medially extending connector pivotally coupled to said fastener engaging member; a first arm having a distal end pivotally coupled to a proximal end of said first pivot arm, said first arm having a medially extending connector; a second link having a distal end pivotally coupled to a second side of said reducing member opposite said first side; a second pivot arm having a distal end pivotally coupled to a proximal end of said second link, said second pivot arm having a medially extending connector pivotally coupled to said medially extending connector of said first pivot arm and also pivotally coupled to said fastener engaging member; and a second arm having a medially extending connector pivotally coupled to said medially extending connector of said first arm, said second arm having a distal end pivotally coupled to a proximal end of said second pivot arm,
- wherein proximal ends of said first and second arm are biased together along a plane offset from the longitudinal axis to move said reducing member distally relative to said fastener engaging member to move the rod toward the bone fastener.
33. The instrument of claim 32, wherein:
- said first arm includes a joint between a proximal end and a distal end of said first arm, said joint defining a proximal portion and a distal portion of said first arm;
- said second arm includes a joint between a proximal end and a distal end of said second arm, said joint defining a proximal portion and a distal portion of said second arm; and
- said proximal portion of said first arm and said proximal portion of said second arm are each pivotal about a respective one of said joints to orient said proximal portions transversely to said distal portions.
34. The instrument of claim 32, wherein said first arm and said second arm are spring biased away from one another.
35. The instrument of claim 32, wherein said actuator assembly includes a locking mechanism at the proximal ends of said first and second arms to hold said reducing member in a reduced position.
36. The instrument of claim 32, wherein said first pivot arm and said second pivot arm each include a lateral offset to locate a proximal portion of the actuator assembly away from a proximal end opening of said fastener engaging member.
37. A surgical instrument for reducing a rod toward a bone fastener, comprising:
- a fastener engaging member extending between a proximal end and a distal end, a distal portion of said fastener engaging member being adapted to engage the bone fastener;
- a reducing member disposed about said fastener engaging member, said reducing member having a longitudinal axis oriented in its direction of movement;
- an actuator assembly coupled between said fastener engaging member and said reducing member and operable to move said reducing member about said fastener engaging member between a reduced position and a retracted position, wherein said actuator assembly includes: a first link having a distal end pivotally coupled to said reducing member; a first arm having a distal end pivotally coupled to said fastener engaging member, said first arm extending to a proximal end, said first arm further being pivotally coupled between said proximal and distal ends to a proximal end of said first link; a second link having a distal end pivotally coupled to said reducing member opposite said first link; and a second arm having a distal end pivotally coupled to said fastener engaging member opposite said first arm, said second arm extending to a proximal end, said second arm further being pivotally coupled between said proximal and distal ends to a proximal end of said second link,
- wherein proximal ends of said first and second arm are biased together along a plane offset from the longitudinal axis to move said reducing member distally relative to said fastener engaging member to move the rod toward the bone fastener.
38. The instrument of claim 37, wherein said actuator assembly, said reducing member, and said fastener engaging member have a common central axis.
39. The instrument of claim 37, wherein said first arm and said second arm each include a laterally extending blocking arm for contacting a proximal end of an access tube and limiting the insertion depth of the surgical instrument therein.
40. A surgical instrument for reducing a rod toward a bone fastener, comprising:
- a fastener engaging member extending between a proximal end and a distal end, a distal portion of said fastener engaging member being adapted to receive a portion of the rod therein and being further adapted to engage the bone fastener;
- a reducing member having (1) a longitudinal axis oriented in a direction of movement of said reducing member, and (2) a body movably disposed about said fastener engaging member, said body having an extension portion extending proximally from a distal end of said reducing member; and
- an actuator assembly, comprising a first arm and a second arm, operable to move said reducing member distally with respect to said fastener engaging member when proximal ends of said first and second arms are biased together, whereby, with biasing together of said first and second arms, said distal end of said reducing member contacts the rod to move the rod distally, relative to said fastener engaging member, toward the bone fastener, wherein said reducing member can be moved distally so that said extension portion is positioned distally of said distal end of said fastener engaging member,
- wherein a plane along which said first and second arms move is offset from the longitudinal axis.
41. The instrument of claim 40, wherein said reducing member defines a passage extending between a proximal end and a distal end thereof.
42. The instrument of claim 41, wherein said passage has a distal portion defined by said extension portion and proximal portion extending from said distal portion to said proximal end of said reducing member, said reducing member defining a lip between said proximal and distal portions of said passage.
43. The instrument of claim 42, wherein said fastener engaging member has an enlarged rim about its distal end, said rim contacting said lip to establish a predetermined reduction distance for said extension portion with respect to said fastener engaging member.
44. A method of reducing an elongated implant member in orthopedic surgery, comprising:
- fixing a fastener to a patient;
- placing an elongated implant member adjacent said fastener;
- providing a rod reducer instrument having a first arm and a second arm;
- inserting said rod reducer instrument through an access tube providing access to said fastener and said elongated implant member;
- placing a distal portion of a fastener engaging member of said rod reducer instrument over said elongated implant member;
- engaging said distal portion of said fastener engaging member to said fastener; and
- moving a reducing member distally about the fastener engaging member so that said reducing member contacts said elongated implant member and forces said elongated implant member toward said fastener, said moving step comprising biasing together proximal ends of said first and second arms to move the reducing member distally to force said elongated implant member toward said fastener,
- wherein said reducing member has a longitudinal axis oriented in a reducing direction and said first and second arms are biased together along a plane offset from the longitudinal axis to move said reducing member.
45. The method of claim 44, further comprising:
- moving said reducing member to position said elongated implant member at a first location in the yoke of the fastener; and
- engaging said elongated implant member in said yoke with a set screw inserted through a passage defined by said fastener engaging member.
46. A method of reducing an elongated implant member in orthopedic surgery, comprising:
- fixing first and second fasteners to a patient;
- placing an elongated implant member adjacent said first and second fasteners;
- providing a rod reducer instrument having a first arm and a second arm;
- placing a distal portion of a fastener engaging member of said rod reducer instrument over said elongated implant member;
- engaging said distal portion of said fastener engaging member of said rod reducer instrument to said fastener;
- moving a reducing member of said rod reducer instrument distally with respect to said fastener engaging member so that said rod reducer instrument contacts said elongated implant member and forces said elongated implant member a first distance toward said first fastener;
- securing said elongated implant member to said first fastener;
- modifying said rod reducer instrument;
- placing the distal portion of the fastener engaging member of the modified rod reducer instrument over said elongated implant member;
- engaging said distal portion of said fastener engaging member of said modified rod reducer instrument to said second fastener;
- moving said reducing member of said modified rod reducer instrument distally with respect to said fastener engaging member so that said modified rod reducer instrument contacts said elongated implant member and forces said elongated implant member a second distance toward said second fastener, said second distance being different than said first distance; and
- securing said elongated implant member to the second fastener,
- wherein said reducing member has a longitudinal axis oriented in a reducing direction and, to move said reducing member distally to force said elongated implant member toward a fastener, said first and second arms are biased together so as to move along a plane offset from the longitudinal axis.
47. The method of claim 46, wherein securing said elongated implant member includes engaging said elongated implant member in a yoke of said first and second fasteners with a set screw inserted through a passage defined by said fastener engaging member of each of said rod reducer instrument and said modified rod reducer instrument.
48. The instrument of claim 1, wherein said surgical instrument includes a viewing area for visualization of the rod and bone fastener when said reducing member brings the rod into contact with the bone fastener.
49. The instrument of claim 18, wherein said surgical instrument includes a viewing area for visualization of the rod and bone fastener when said reducing member brings the rod into contact with the bone fastener.
50. The instrument of claim 1, wherein said first and second arms are actuated about a common pivot axis located between proximal and distal ends of said first and second arms.
51. The instrument of claim 1, wherein a longitudinal axis of said reducing member intersects a pivot axis about which said first and second arms pivot.
52. The instrument of claim 1, wherein said fastener engaging member defines a passage, along a longitudinal axis, having first and second openings aligned with the longitudinal axis, with said first opening of said passage being at said distal portion of said fastener engaging member, and
- wherein said first and second arms are pivotally coupled to each other at a position along said instrument spaced proximally from said second opening.
53. The instrument of claim 1, wherein said first arm is pivotally coupled to said second arm,
- said fastener engaging member and said reducing member are reciprocally slidably coupled,
- said first and second arms are actuated about a common pivot axis located between proximal and distal ends of said first and second arms, and
- said reducing member moves the rod in a longitudinally oriented direction with respect to the bone fastener.
54. The instrument of claim 53, wherein said fastener engaging member includes a pair of flex arms extending proximally from said distal end thereof, and wherein said reducing member and said fastener engaging member each include a generally circular cross-section.
55. The instrument of claim 18, wherein said first and second arms are actuated about a common pivot axis located between proximal and distal ends of said first and second arms.
56. The instrument of claim 18, wherein a longitudinal axis of said reducing member intersects a pivot axis about which said first and second arms pivot.
57. The instrument of claim 18, wherein said passage extends along a longitudinal axis of said fastener engaging member, between said proximal end opening and a distal end opening, said openings aligned with the longitudinal axis, and
- wherein said first and second arms are pivotally coupled to each other at a position along said instrument spaced proximally from said proximal end opening.
58. The instrument of claim 18, wherein said first arm is pivotally coupled to said second arm,
- said fastener engaging member and said reducing member are reciprocally slidably coupled,
- said first and second arms are actuated about a common pivot axis located between proximal and distal ends of said first and second arms, and
- said reducing member moves the rod in a longitudinally oriented direction with respect to the bone fastener.
59. The instrument of claim 58, wherein said fastener engaging member includes a pair of flex arms extending proximally from said distal end thereof, and wherein said reducing member and said fastener engaging member each include a generally circular cross-section.
60. The instrument of claim 39, wherein said surgical instrument includes a viewing area for visualization of the rod and bone fastener when said reducing member brings the rod into contact with the bone fastener.
61. The method of claim 44, further comprising viewing said elongated implant member and said fastener during said moving step when said elongated implant member and said fastener are brought into contact.
62. The method of claim 44, wherein said sub-step moves the rod in a longitudinally oriented direction with respect to said fastener.
63. The method of claim 62, wherein said first and second arms are actuated about a common pivot axis located between proximal and distal ends of said first and second arms.
64. The method of claim 44, wherein a longitudinal axis of a reducing member of said rod reducer instrument intersects a pivot axis about which said first and second arms pivot.
65. The method of claim 44, wherein said fastener engaging member defines a passage, along a longitudinal axis, having first and second openings aligned with the longitudinal axis, with said first opening of said passage being at said distal portion of said fastener engaging member, and
- wherein said first and second arms are pivotally coupled to each other at a position along said instrument spaced proximally from said second opening.
3604487 | September 1971 | Gilbert |
3844291 | October 1974 | Moen |
4411259 | October 25, 1983 | Drummond |
5020519 | June 4, 1991 | Hayes et al. |
5113685 | May 19, 1992 | Asher et al. |
5308357 | May 3, 1994 | Lichtman |
5314431 | May 24, 1994 | Graziano |
5330472 | July 19, 1994 | Metz-Stavenhagen |
5364397 | November 15, 1994 | Hayes et al. |
5389099 | February 14, 1995 | Hartmeister et al. |
5392978 | February 28, 1995 | Velez et al. |
5423855 | June 13, 1995 | Marienne |
5449361 | September 12, 1995 | Preissman |
5458608 | October 17, 1995 | Wortrich |
5466243 | November 14, 1995 | Schmieding et al. |
5588580 | December 31, 1996 | Paul et al. |
5616143 | April 1, 1997 | Schlapfer et al. |
5720751 | February 24, 1998 | Jackson |
5782830 | July 21, 1998 | Farris |
5782831 | July 21, 1998 | Sherman et al. |
5810878 | September 22, 1998 | Burel et al. |
5855311 | January 5, 1999 | Hamblin et al. |
5899901 | May 4, 1999 | Middleton |
5910141 | June 8, 1999 | Morrison et al. |
5944720 | August 31, 1999 | Lipton |
6036692 | March 14, 2000 | Burel et al. |
6042582 | March 28, 2000 | Ray |
6063088 | May 16, 2000 | Winslow |
6261296 | July 17, 2001 | Aebi et al. |
6440133 | August 27, 2002 | Beale et al. |
6790209 | September 14, 2004 | Beale et al. |
6830570 | December 14, 2004 | Frey et al. |
7156849 | January 2, 2007 | Dunbar et al. |
7470279 | December 30, 2008 | Jackson |
7611517 | November 3, 2009 | Lim |
7625376 | December 1, 2009 | Brumfield et al. |
20040267275 | December 30, 2004 | Cournoyer et al. |
20050192570 | September 1, 2005 | Jackson |
20050192579 | September 1, 2005 | Jackson |
20050228400 | October 13, 2005 | Chao et al. |
20060036244 | February 16, 2006 | Spitler et al. |
20060074418 | April 6, 2006 | Jackson |
20060111712 | May 25, 2006 | Jackson |
20060173454 | August 3, 2006 | Spitler et al. |
20070270867 | November 22, 2007 | Miller et al. |
20070270868 | November 22, 2007 | Dewey |
20070276379 | November 29, 2007 | Miller et al. |
20080077139 | March 27, 2008 | Landry et al. |
20080091213 | April 17, 2008 | Jackson |
20080234678 | September 25, 2008 | Gutierrez et al. |
20080234765 | September 25, 2008 | Frasier et al. |
4238339 | May 1994 | DE |
995769 | February 1983 | RU |
- Sofamor, “Introducteur Conteur De Tige” (Engineering Drawings, Jan. 1, 1994.
- Sofamor, “Introducteur—Contreur De Tige” (schematic drawings), Jan. 1, 1994.
- Laufer and Bowe, CD Horizon Spinal System, Surgical Technique, 1996, Sofamor Danek.
- TSRH-3D Vertebral Body Reduction Instrumentation, 2001, Medtronic Sofamor Danek.
- Shufflebarger et al., Taking Spinal Instrumentation to a New Dimension, 1995.
- Laufer and Bowe, CD Horizon Spinal System, Surgical Technique, 1999, Sofamor Danek.
- Moss® Miami 3-Dimensional Instrumentation Product Catalogue, 1995, Depuy Motech, Inc.
- Pediatric Isola® Spinal System, Ordering Information for Implants and Instruments, 1998, AcroMed Corporation.
- Orthopedic Sourcebook, Instruments for Surgeons, Section K, 1999, Medic.
- Z Spinal Instrumentation, Section D, 1987, Zimmer, Inc.
- Sofamor Rod Reducer (1994).
Type: Grant
Filed: Mar 20, 2008
Date of Patent: Jun 11, 2013
Assignee: Warsaw Orthopedic, Inc. (Warsaw, IN)
Inventors: Jeffrey W. Beale (Bartlett, TN), John Stewart Young (Memphis, TN)
Primary Examiner: Pedro Philogene
Application Number: 12/052,438
International Classification: A61B 17/56 (20060101);