WO2015059590A1 - Low profile fixation device - Google Patents

Abstract

Low profile screws include a screw body which houses a rod end and any other internal components, such as locking pins, at a height that does not project upward significantly beyond the screw body.

Description

LOW PROFILE FIXATION DEVICE

CROSS REFERENCES TO RELATED APPLICATIONS

This application is related to and claims priority from commonly owned U.S. Provisional Patent Application Serial No. 61/893,910, entitled: LOW PROFILE ATTACHMENT OF ROD TO SCREWS, filed October 22, 2013, the disclosure of which is incorporated by reference in its entirety herein.

TECHNICAL FIELD

The present invention is directed to orthopedic screws in which rods are secured, in order to connect the screws.

BACKGROUND

Pedicle screws are used in spinal fixation and fusion surgery as anchor points in the vertebrae, for supporting a rod, that is connected between pedicle screws. For example, pedicle screws attach to the vertebrae at the pedicles. The pedicle screws are. placed at two, three or more spine segments (sometimes consecutively), and then a rod is connected to the screws. This arrangement prevents motion at the vertebrae that are being fixated or fused.

In the case of fusion, after the bone graft grows, and the vertebrae are securely fused, the screws and rods are not needed anymore for stability and may be safely removed with a subsequent back surgery. However, most surgeons do not recommend removal unless the pedicle screws cause discomfort for the patient (5% to 10% of cases).

Conventional pedicle screws include a threaded shaft, for placement in the pedicle, and a head, for example, of a tulip shape, which receives a rod. The rod is top™ loaded into the tulip of the head. The rod is locked in place when the surgeon has obtained optimal correction of the spine segments operated on. The locking is carried out by placing set screws into the tulips (which have complementary threads) to force the rod into the tulip cradle and fixate the rod in the tulip by turning the set screw.

The set screw is positioned above (beyond) the rod. To allow this position, the walls of the tulip have been elongated to house an inner thread (or other mechanical interface) and allow positioning and tightening by the set screw. Thus, the set screw, upon being tightened into the tulip, projects above the rod. This projection is

unacceptable, especially in young patients with spinal defonnities, such as scoliosis, as it is uncomfortable, especially when sitting, and can be felt under their skin, as the spinal soft tissues are scant.

SUMMARY

The present invention lowers the profile of set screws by providing a low profile fixation device, for housing a rod edge (end) and any other internal components, such as locking pins, at a height that does not project upward beyond the body of the set screw, or to a height: even with or slightly beyond the set screw body of the fixation device.

Moreover, the set screw body and the uppermost surface of the rod and or other internal components terminate at approximately the same plane.

Embodiments of the present invention are directed to an orthopedic apparatus. The apparatus comprises a shaft portion for engaging a bony structure, including, for example, a vertebrae, and, a body in communication with the shaft portion. The body includes an area for receiving and retaining a connector rod and arj engagement mechanism for communication with a rod. The engagement mechanism is moveable between a first position for receiving the rod, and, a second position where the rod is secured by a frictional contact in a locking engagement in the body.

Optionally, the body includes a first edge and a second edge, oppositely disposed from each other, the second edge defining an upper surface, and when the engagement mechanism is in the second position, the engagement mechanism, the rod, and the upper surface of the body are at least substantially coplanar with respect to each other.

Optionally, the body includes an upper surface and the rod extends to a point which is not beyond the upper surface.

Optionally, the engagement mechanism includes at least one locking pin, the at least one locking pin disposed on a lateral side of the body, the lateral side adjacent both the first edge and the second edge.

Optionally, the engagement mechanism includes locking pins, the locking pins disposed on opposite lateral sides of the body, the lateral sides adjacent both the first edge and the second edge. Optionally, the at least one locking pin is configured to rotate around the rod, and defines at least a portion of the area.

Optionally, the locking pins are configured to rotate around the rod.

Optionally, the locking pins include a curved inner surface to receive and rotate around a rod of a circular shaped cross section.

Optionally, the engagement mechanism includes at least one locking cam, the at least one locking cam disposed on a lateral side of the body, the lateral side adjacent both the first edge and the second edge, the locking cam movable between the first position and the second position by rotating the locking cam.

Optionally, the engagement mechanism includes locking cams, the locking cams disposed on opposite lateral sides of the body, the lateral sides adjacent both the first edge and the second edge, the locking cams movable between the first position and the second position by rotating the locking cams.

Optionally, the at least one locking pin is configured to move linearly along and in frictional contact with the rod.

Optionally, the locking pins are configured to move linearly along- and in frictional contact with the rod.

Optionally, the shaft is attached to the body at the first edge.

Optionally, the shaft is pivotally mounted to the body.

Optionally, the area extends through the body.

Embodiments of the invention are directed to a body for an orthopedic apparatus. The body comprises an area extending through the body for receiving and retaining a connector rod and an engagement mechanism for frictional communication with the connector rod. The engagement mechanism is moveable in the area between a first position for receiving a connector rod, and, a second, position, where the engagement mechanism wedges the connector rod in the area to lock the connector rod therein.

Optionally, the engagement mechanism defines at least a portion of the area.

Optionally, the body additionally comprises a shaft including threading for engaging a bony structure, for example, a vertebrae.

Other embodiments of the present invention are directed to a method for connecting a connector rod. The method comprises obtaining an orthopedic apparatus. The orthopedic apparatus comprises a shaft portion for engaging a bony stmcture, and, a body in communication with the shaft portion, The body includes an area for receiving and retaining a connector rod and an engagement mechanism for communication with a rod. The engagement mechanism is moveable between a first position, for receiving the rod, and, a second position, where the rod is secured by a frictional contact in a locking engagement in the body. At least the shaft portion is then placed into a bony structure. The connector rod is inserted into the receiving area of the body when the engagement mechanism is in the receiving position; and, the engagement mechanism is moved in the area to the second position, to lock the connector rod in the area of the body.

Optionally, bony structure includes a pedicle of a vertebrae.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described belo w. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Attention is now directed to the drawings where like numerals or characters represent like or corresponding components. In the drawings:

FIG. 3 is a perspective view of an apparatus in accordance with an embodiment of the invention;

FIG. 2 A is a cross-sectional view of the apparatus of FIG. 1 taken along line 2-2 of FIG. 1, showing the locking pins in a first or receiving position;

FIG. 2B is a cross-sectional view of the apparatus of FIG. 1 taken along line 2-2 of FIG. 1, showing the locking pins in a second or locking position;

FIG. 3 A is a perspective view of a representative locking pin used in the apparatus of FIGs. 1, 2A and 2B;

FIG. 3B is a perspective view of an alternative locking pin for use in the apparatus of FIGs. l , 2A and 2B;

FIG. 4A is a side view of an alternative rod for use with the apparatus of the disclosed embodiments;

FIG. 4B is a perspective view of the alternative rod of FIG. 4A;

FIG. 5 A is a perspective view of an apparatus in accordance with another embodiment of the invention;

FIG. 5B is a perspective view of a representative locking cam used in the apparatus of FIGs. 5 A, 6 A and 6B;

FIG. 5C-1 and 5C-2 are top and bottom perspective views, respectively, of alternative cams used in the apparatus of FIGs. 5A, 6A and 6B;

FIG. 5C-3 is a top view of the alternative cams used in the apparatus of FIGs. 5 A, 6 A and 6B;

FIG. 6A is a cross-sectional view of the apparatus of FIG. 5A taken along line 6-6 of FIG. 5A, showing the locking cams in a first or receiving position;

FIG. 6B is a cross-sectional view of the apparatus of FIG. 5A taken along line 6-6 of FIG. 5A, showing the locking cams in a second or locking position;

FIG. 7 is a cross sectional view of an alternative embodiment of the apparatus of FIG. 5A, 6A and 6B;

FIG. 8 is a perspective view of an apparatus in accordance with another embodiment of the invention;

FIG. 9A-1 is a cross-sectional view of the apparatus of FIG. 8 taken along line 9-1 - 9-1 of FIG. 8, showing the locking pins in a first or receiving position;

FIG. 9A-2 is a cross-sectional view of the apparatus of FIG. 8 taken along line 9-2 - 9-2 of FIG. 8, showing the locking pins in a first or receiving position;

FIG. 9B is a cross-sectional view of the apparatus of FIG. 8 taken along line 9-1 - 9-1 of FIG. 8, showing the locking pins in a second or locking position;

FIG. 9B-2 is a cross-sectional view of the apparatus of FIG. 8 taken along line 9-2 - 9-2 of FIG. 8, showing the locking pins in a second or locking position; and,

FIG. 10 is a perspective view of the apparatus of FIG. 8 with an alternative shaft.

DETAILED DESCRIPTION OF THE DRAWINGS Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

Throughout this document, references to directions and orientations, such as upward, downward, upper, lower, up, down, top, bottom, inward, outward, lateral, and the like, are made. These references are exemplary, for describing and explaining the present invention, and embodiments thereof, and are not limiting in any way.

Attention is now directed to FIGs. 1, 2A, 2B, 3 A and 3B. There is shown an apparatus 100 in accordance with an embodiment of the present invention. The apparatus 100 is an orthopedic apparatus, such as a spinal or other fixation apparatus, for example, a screw, including a pedicle screw. The apparatus 100 includes a shaft 102 and a body 104. The body 104 includes an upper surface or edge 104x, a lower surface or edge 104y, lateral or side surfaces or edges 104zl, 104z2, front side surfaces or edges 1.04f and rear side surfaces of edges 104r, and an interior area or channel 106, which, for example, extends through the body 104, for receiving a rod 1 10 and where the rod 1 10 is secured in place, by locking pins 112a, 1 12b. The locking pins 112a, 1 12b are movably maintained in slots 1 13a, 1 13b on the body 104, so as to confine their movement to rotational- upward and downward, between a first or receiving position, shown in FIG. 2A, and a second or locking position, as shown in FIG. 2B. In this locking position, the rod 110 is secured in the body 104.

The shaft 102 and body 104, are, for example, integral, but may be formed from multiple pieces. The shaft 102 is typically threaded, at one or more pitches, so as to be screwed into bone or bony structures, hard tissue, for example, vertebrae, and in particular, the pedicles of the vertebrae. The shaft 102 may terminate in a blunt point (such as point 302p in FIG. 8), or at a point to be self-tapping (302y in FIG. 10), A central cannula (bore) 114, for example, extends through the center of the shaft 102 and may extend into the body 104. This central cannula 1 14 is, for example, parallel to the longitudinal axis LAI extending through the apparatus 100. The apparatus 100, shaft 02, body 104, and locking pins 112a, 112b, are made of materials such as stainless steel, titanium, surgical grade metals and the like, by conventional techniques.

The body 104 includes oppositely disposed shoulders 130a, 130b on opposite lateral sides 104a, 104b of the body 104. The shoulders 130a, 130b define an end of the apparatus 100, or upper portion of the body 104. The shoulders 130a, 130b each include interior walls 132a, 132b, which are, for example, curved to accommodate the curvature of the locking pins 112a, 112b, with the space therebetwen defining being part of the channel 106. The channel 106 extends through the body 104. Recesses 136a, 136b form the lower portion of the body 104. The recesses 136a, 136b, which may also be formed of indentations and apertures or other mechanical interface, are bounded on an upper side by an outwardly tapered wall 138a, 138b of the shoulder 130a, 130b, and on a lower side by a base wall 140a, 140b, which is, for example, perpendicular to the longitudinal axis LAI of the apparatus 100. The outwardly tapered walls 138a, 138b meet the respective curved interior walls 132a, 132b at a point 141a, 141b, which is, for example, rounded.

The recesses 136a, 136b are open on the lateral sides (lateral side surfaces 104zl, 104z2), allowing the operator access to the locking pins 112a, 112b, for moving the locking pins 1 12a, 112b, between the first receiving position (FIG. 2A) and second locking position (FIG. 2B). The body 104 and locking pins 1 12a, 112b, are for example, symmetric with respect to the longitudinal axis LAI of the apparatus 100.

The locking pins 1 12a, 112b include a first or upper portion, formed of a curved element 150 and a second or lower portion, formed of a flange 152. The flange 152 includes a cut-out portion 154, to enable grapping and movement of the locking pin 112a, 1 12b, between the first and second positions, by a finger, tool, or the like. The flange 152 includes an inner surface 152a, extending from the cut-out potion. 154 to the inner surface 150a of the curved element 150.

The inner surface 150a of the curved element 150 is of a curvature corresponding to that of the curvature of the rod 1 10. For example, the radius of curvature of the inner surface 150a is of a radius of curvature equal to or slightly greater the radius of curvature of the rod 3 10, to allow for frictional movement, e.g. rotation, of the locking pin 1 12a, 112b with respect to the rod 1 10, when the locking pin 1 12a, 112b moves between the first and second positions. The outer surface 150b of the curved element 150 is of a curvature con-esponding to the curvature of the interior walls 132a, 132b of the body 104. For example, the radius of curvature of the outer surface 150b is equal to or slightly less that the radius of curvature of the interior walls 132a, 132b, to allow frictional movement, e.g., rotation of the locking pins 112a, 112b with respect to the interior walls 132a, 132b of the body 104,

The outer surface 150b of the curved element 150, coupled with an intermediately located groove 158 (of a curvature corresponding to the curvature of the points 141 a, 141b), and the outer surface 152b of the flange 152, corresponds to the shape of the inner surface 160a, 160b of the shoulders 130a, 130b (the inner surfaces 160a, 160b formed of the interior walls 132a. 132b coupled with the points 141a, 141b and the outwardly tapered walls 138a, 138b of the shoulders 130a, 130b). This arrangement serves to limit the rotation or travel of the locking pins 112a, 1.2b, when, moved, for example, outward, and upward, so as to rotate the locking pins 112a, 1 12b into the second or locking position (FIG. 2B), to maintain a frictionally tight locking of the rod 110, by wedging the rod 10 between the locking pins 112a, 112b, specifically, wedging the rod 110 between the curved elements 150 of the locking pins 112a, 112b, as shown in FIG. 2B. Also in this locking position, the edges of the flanges 152c are, for example, either inside the body 104 or flush with the lateral side surfaces or edges 104zl, 104z2 of the body 104. Remaining in FIG. 2B, the locking of the rod 1 10 in the body 104 by the locking pins 112a, 112b is such that the highest point of the rod 110, and/or the ends 1 12ax, 1 12bx of the locking pins 112a, 1 12b are coplanar or approximately coplanar, slightly above or below, the plane formed by the upper surface or upper edge 104 x of the body 104. The body 104, and hence, the apparatus 100, has a "low profile" as little, if any of the rod 1 10 and/or locking pins 1 12a, 112b, extend above or beyond the body 104 (e.g., the upper surface 104x of the body 104), and little if any of the body 104 extends above or beyond the rod 3 10 and/or locking pin ends 112ax, 112bx.

FIG. 3 A shows the locking pins 112a, 112b, represented by the locking pin 112b, formed of a single curved element 150. Alternatively, as shown in FIG. 3B, a locking pin 1 12b' with multiple aligned curved portions 150' may be used as the locking pins and 1 12a and 1 12b.

Other alternative locking pins may be of cross sectional shapes other than rounded or curved, and may include rectangular or other cross-sectional shape, and may be implemented as a wide, flat bolt or plate. Furthermore, the cross-sectional dimensions may vary along the length of the locking pin, for example, having a wide region for contacting the rod to distribute wedging/clamping forces over a relatively large area, while having a narrower shaft used to actuate and/or guide motion of the locking pin(s).

The rod 110 is, for example, straight or curved (with an anatomical curvature such as lordosis). The rod 1 10 is also known as a connector rod, as a single rod 110 is used to connect at least two apparatus 100 (as well as apparatus 200, 200' and 300 detailed below). The rod 110 may be smooth or may have ridges 172, for example, as shown in the rod 1 lO' of FIGs. 4A and 4B, such that the ridges 172 coincide with the locking pins 112a, 1 12b. The shape of the ridges 172 increases the contact surface (interface) between the rod 1 10' and the locking pins 112a, 12b, inhibits loosening of the rod 1 10' when locked in the body 104, and also prevents axial motion of the rod 110' along the body 104. While the rod 110 is used with the apparatus 100, and 200, 200' and 300 (detailed below), the alternative rod 110' is also usable with these apparatus 100, 200, 200', 300. Both rods 1 10, HO' are made from stainless steel, titanium or other surgical grade metals by conventional techniques.

In an exemplary operation of the apparatus 100, the locking pins 1 12a, 1 12b are in a first position, for receiving a rod 110, as shown in FIG. 2 A. The locking pins 1 12a, 1 12b are positioned where the flanges 152 are close to and typically abutting the base walls 140a, 140b.

With the rod 1 10 having been placed in the body 104, the locking pins 112a, 112b are moved upward, as the flanges 152 are moved (outward and toward the upper surface or edge 104x) upward (and outward) by an instrument, by engaging the cut out portions 154 of the respective flange 152. The locking pins 1 12a, 1 12b are moved upward (toward the upper surface 104x) with their curved portions 150 rotating and converging around the rod 110 (pushing the rod 1 10 slightly downward in the direction of the lower surface 104y, for example, so as to wedge it in the area 106). Coupled with the frictional engagement with the rod 1 10, the locking pins 112a, 1 12b, via the curved portions 150, wedge the rod 110 in the body 104, as the locking pins 1 12a, 1 12b have moved into a second, secured or locked position, in the body 104, as shown in FIG. 2B. Also in this second position, the flange 152 outer walls 152b abut the respective recess tapered walls 138a, 138b. in moving from the first position to the second locking position, the locking pins 112a, 112b are moved upward (in the direction toward the upper surface 104x) either individually or simultaneously.

This process can be reversed, by moving the flanges 152 downward, for example, in the direction toward the lower surface 104y. For example, this may be performed with instrumentation capable of moving the flanges 152 in the respective recesses 136a, 336b.

Alternatively, the apparatus 100 is operable with only one locking pin. In other alternative embodiments, two or more locking pins may be used, and they may be on the same or different sides of the body 104. In the case where pins are on different sides of the body 104, they are positioned in directly opposing pairs. Alternately, these multiple pins on different sides of the body 104 may be staggered in alternating relation between the two sides of the rod 110.

With respect to the locking pins 1 12a, 112b, it should be noted that there are not any limitations on the particular cross-sectional shape or proportions of the locking pin, which may be implemented with round, rectangular or other cross-sectional shapes, and may be implemented as a wide, flat bolt or plate. Furthermore, the cross-sectional dimensions may vary along the length of the locking pin, for example, having a wide region for coming in contact with the rod 110 so as to spread wedging and/or clamping forces over a relatively large area while having a narrower shaft used to actuate and/or guide motion of the locking pins.

FIGs. 5A, 5B, 6A, and 6B detail another embodiment of the invention. FIGs. 5A, 6 A and 6B show an apparatus 200. The apparatus 200 is an orthopedic apparatus. For example, the apparatus 200 includes a spinal or other fixation apparatus, for example, a screw, such as a pedicle screw. The apparatus includes a shaft 202 (for example, with a central cannula 214 extending therethrough), and a body 204. The body 204 includes an upper surface or edge 204x, a lower surface or edge 204y, lateral side surfaces or edges 204zl, 204z2, a front side surface or edge 204f, and a rear side surface or edge 204r. The body 204 is symmetric with respect to its longitudinal axis LA2, at its lateral sides, 204a, 204b, and includes an interior area or channel 206 for receiving a rod 110 and where the rod 1 10 is secured in place, by locking cams 212a, 212b. The locking cams 212a, 212b are positioned in the body 204 in the lateral sides 204a, 204b, which are, for example, inwardly tapered (upward).

A central cannula 214, for example, extends through the shaft 202 and typically a portion of the body 204. This central cannula 214 is, for example, parallel with the longitudinal axis LA2. The apparatus 200 and components thereof are of the same or similar materials to those of the apparatus 100 and components, and made by the techniques disclosed for apparatus 100.

As shown in FIG. 5B, each cam 212a, 212b, represented by the cam 212b, includes a base 273, which is, for example, oval in shape, such that platforms 273x extend along the longitudinal axis LAC, from a head portion 274. The head portion 274 protrudes from the base 273. The head portion 274 mcludes a threaded outer surface 276 and an indentation 278 for, example, hexagonal in shape, for receiving a hexagonal tool.

FIGs. 5C-1, 5G-2 and 5C-3 show an alternative cam 212', known for example as a "one sided" cam, which may be used as cams 212a, 212b, with the apparatus 200, 200'. The cam 212' is similar to cams 212a, 212b, except that the base 273' is of a single platform 273x', extending on one side of the cam 212'. This cam 212' is such that corresponding structures to cams 212a, 212b are similarly numbered and in accordance with the descriptions above. The half platform 273x' extends along the longitudinal axis LAC from a head portion 274. The head portion 274 includes a threaded outer surface 276 and an indentation 278 for, example, hexagonal in shape, for receiving a hexagonal tool.

Turning to FIGs. 6A and 6B, the body 204 includes recesses 216a, 216b for accommodating the cams 212a, 212b in a moveable and frictional engagement. The recesses 216a, 216b, include tube portions 217a, 217b, corresponding to the shape of the head portion 274 of the cams 212a, 212b, and which are correspondingly threaded to the threading 276 the head portion 274. The recesses 216a, 216b also include slots 218a, 218b, for accommodating the platforms 273x of the base 273 of the cams 212a, 212b. The body 204 is dimensioned to provide a gap 219a, 219b, for the platforms 273 of the base 273, between the body 204 and the rod 1 10.

FIG. 6A, shows the body 204 in a first or receiving position for the rod 110, with the cams 212a, 212b aligned such that the longitudinal axis LAC is, for example, perpendicular or substantially perpendicular to the longitudinal axis LA2 of the apparatus 200 (a "perpendicular orientation"). The cams 212a, 212b, are moveable, for example, by rotating them with an instrument inserted into the indentation 278 of the head portion 274.

This rotation moves the cams 212a, 212b, from the first position, to a second or locking position, where the rod 110 is secured in the body 104. The rotation of the cams 212a, 212b moves them inward in the recesses 216a, 216b (toward the center of the body 204), in accordance with the threading. This inward movement and rotation places the platforms 273x of the base 273 of the respective cams 212a, 212b in the gap 219a, 219b and the slots 218a, 218b. This rotation results in maximum contact between the base 273, i.e., platforms 273x, and the rod 110, for example, where the longitudinal axis LAC of the cams 212a, 212b is parallel or substantially parallel with the longitudinal axis LA2 of the apparatus 200 (a "parallel orientation").

The rotation, coupled with the inward movement of the cams 212a, 212b, results in a wedging force on the rod 110, that engages and locks the rod 110, securely in the body 204, as shown in FIG. 6B. This second locking position in the apparatus 200 is similar to that of the second locking position of the apparatus 100, in that the apparatus 200 is "low profile", as the locking cams 212a, 212b, and/or rod 110, are coplanar or approximately coplanar, slightly above or below, the plane formed by the upper surface or upper edge 204x of the body 204.

The aforementioned process of moving from the first receiving position to the second locking position is reversible. For example, from the second or locking position, the cams 212a, 212b can be rotated oppositely, to move the cams 212a, 212b outward and back to the perpendicular orientation, so as to return to the first or receiving position of FIG. 6A.

Depending on the pitch of the threading, the aforementioned parallel orientation of the cams 212a, 212b, can be achieved with various rotations of the cam 212a, 212b. For example, these rotations to reach the parallel orientation of FIG. 6B may range from approximately 5 to approximately 90 degrees from the perpendicular orientation of FIG. 6 A. Should cam 212' be used as the cams 212a, 212b, these rotations to reach the parallel orientation of FIG. 6B may be up to approximately 1.80 degrees from the perpendicular orientation of FIG. 6 A.

FIG. 7 shows an alternative apparatus 200', which is similar to the apparatus 200 in construction and materials (with element numbers being the same except where indicated), except that the shaft 202' is a separate piece from the body 204. The shaft 202' terminates in a sphere 280. The sphere 280 is movably mounted in the body 204 in a chamber 290, at a lower end of the body 204. As a result of this attachment, the shaft 202' is moveable in multiple directions, so as to be polyaxial with respect to the body 204.

Alternatively, the apparatus 200, 200' is operable with only one locking cam. In other alternative embodiments, two or more locking cams may be used, and they may be on the same or different sides of the body 204. In the case where cams are on different sides of the body 104, they are positioned in directly opposing pairs. Alternately, these multiple cams on different sides of the body 204 may be staggered in alternating relation between the two sides of the rod 110.

FIGs. 8, 9A-1, 9A-2, 9B~1 and 9B-2 detail another embodiment of the invention, an apparatus 300. FIG. 8 shows an apparatus 300. The apparatus 300 is an orthopedic apparatus. The apparatus 300 is, for example, spinal or other fixation device, such as a screw, including a pedicle screw. The apparatus 300 includes a shaft 302, which for example terminates at a blunt point 302p, and a body 304. The body 304 includes an upper surface or edge 304x and a lower surface or edge 304y, lateral side surfaces or edges 304zl, 304z2, a front side surface or edge 304f and a rear side surface or edge 304r. The body 304 includes an interior area or channel 306 for receiving a rod 110 (for example, as shown in FIG. 9A-1, without the rod 110 and in FIG. 9A-2 with the rod 110), and where the rod 110 is secured in place, by locking pins 312a, 312b (FIGs. 9B-1 and 9B~2). A central cannula 314, for example, extends through the apparatus 300, parallel to the longitudinal axis LA3.

The locking pins 312a, 312b are positioned in the body 304 to contact the rod 110 laterally and at an inward angle, to wedge the rod 1 10 in a locked, position when the locking pins 312a, 312b are moved upward, in slots 313a, 313b in the lateral sides 304a, 304b of the body 304. The slots 313a, 313b are, for example, inwardly tapered (upward in the direction of surfaces 304x). As shown in FIG. 9A-2, the tapering of the slots 313a, 313b and the orientation of the locking pins 312a, 312b is at an angle Θ with respect to the longitudinal axis LA3. For example, angle Θ is approximately 5 to 35 degrees. The apparatus 300 and components thereof are of the same or similar materials to those of the apparatus 100 and components, and made by the techniques disclosed for apparatus 100.

The lower or projecting end 312ay, 312by, of each locking pin 312a, 312b connects to a respective flange 352, which is movable, for example, by sliding, on a track 316b on opposite lateral sides of the slots 313a, 313b (only one track shown on side 304b with the tracks not shown on side 304a) in the body 304, between a first or lower position, where the locking pins 312a, 312b are in a receiving position, as shown in FIG. A-2, and a second or upper position, where the locking pins 312a, 332b are in a position in contact with the rod 110, such that the rod is wedged in frictional contact in a secured and locked position in the body 304, as shown in FIGs. 9B-1, 9B-2.

The flanges 352 each include an indentation 354, which can be gripped by an instrument, finger or the like, to move the flanges 352, and ultimately the locking pins 312a, 312b, between the first rod receiving position (FIG. 9A-2) and second rod locking position (FIGs. 9B-1, 9B-2). This second locking position in the apparatus 300 is similar to that of the second locking position of the apparatus 100, in that the apparatus 300 is "low profile", as the locking pin upper ends 312ax, 312bx, and/or rod 1 10, are coplanar or approximately coplanar, slightly above or below, the plane formed by the upper surface or upper edge 304x of the body 304.

Additionally, as shown in FIGs. 9A~1_? 9A-2, 9B-1 and 9B-2, the locking pins 312a, 312b, body 304 and flanges 352 are symmetric with respect to the longitudinal axis LA3.

Alternatively, the apparatus 300 is operable with only one locking pin. In other alternative embodiments, two or more locking pins may be used, and they may be on the same or different sides of the body 304. In the case where pins are on different sides of the body 304, they are positioned in directly opposing pairs. Alternately, these multiple pins on different sides of the body 304 may be staggered in alternating relation between the two sides of the rod 110.

FIG. 10 shows the apparatus 300 with a self-tapping shaft 302'. The shaft 302' is considered to be self-tapping as it is tapered inward, the threading 302x extends to the tip 302y, and there is a cut 302z in the tip 302y.

While the apparatus 100, 200, 200' and 300 have been described with rods 110, 110a extending through the bodies 104, 204, 304, one of the front 104f, 204f, 304f or rear 104r, 204r, 304r sides could be closed, to serve as a capping member for an end segment.

While the apparatus 100, 200, 200' and 300 have been described with polygonal bodies 104. 204, 304, this is exemplary only, as these bodies may also be round in shape, and include an interior area or channel (similar to interior area or channels 106, 206, 306 in the respective apparatus 100, 200, 200', 300), or portion thereof extending in and/or through the rounded body.

While the apparatus 100, 200, 200' and 300 have been described as pedicle screws, this is exemplary only, as these apparatus 100, 200, 200' and 300 have wide ranging orthopedic applications. These apparatus 100, 200, 200' and 300, as detailed herein or modified, are usable with any type of bony structure or hard tissue, for orthopedic and other surgical applications.

As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope of the appended claims.

Claims

What is claimed is:

1. An orthopedic apparatus comprising:

a shaft portion for engaging a bony structure, and,

a body in communication with the shaft portion, the body including an area for receiving and retaining a connector rod and an engagement mechanism for

communication with a rod, the engagement mechanism moveable between a first position for receiving the rod, and, a second position where the rod is secured by a frictional contact in a locking engagement in the body.

2. The orthopedic apparatus of claim 1, wherein the body includes a first edge and a second edge, oppositely disposed from each other, the second edge defining an upper surface, and when the engagement mechanism is in the second position, the engagement mechanism, the rod, and the upper surface of the body are at least substantially coplanar with respect to each other.

3. The orthopedic apparatus of claim 1, wherein body includes an upper surface anctfhe rod extends to a point which is not beyond the upper surface.

4. The orthopedic apparatus of claim 1, wherein the engagement mechanism includes at least one locking pin, the at least one locking pin disposed on a lateral side of the body, the lateral side adjacent both the first edge and the second edge.

5. The orthopedic apparatus of claim 1, wherein the engagement mechanism includes locking pins, the locking pins disposed on opposite lateral sides of the body, the lateral sides adjacent both the first edge and the second edge.

6. The orthopedic apparatus of claim 1, wherein the at least one locking pin is configured to rotate around the rod, and defines at least a portion of the area.

7. The orthopedic apparatus of claim 5, wherein the locking pins are configured to rotate around the rod.

8. The orthopedic apparatus of claim 7, wherein the locking pins include a curved inner surface to receive and rotate around a rod of a circular shaped cross section.

9. The orthopedic apparatus of claim 1, wherein the engagement mechanism includes at least one locking cam, the at least one locking cam disposed on a lateral side of the body, the lateral side adjacent both the first edge and the second edge, the locking cam movable between the first position and the second position by rotating the locking cam.

10. The orthopedic apparatus of claim 1, wherein the engagement mechanism includes locking cams, the locking cams disposed on opposite lateral sides of the body, the lateral sides adjacent both the first edge and the second edge, the locking cams movable between the first position and the second position by rotating the locking cams.

1 1. The orthopedic apparatus of claim 4, wherein the at least one locking pin is configured to move linearly along and in frictional contact with the rod.

12. The orthopedic apparatus of claim 5, wherein the locking pins are configured to move linearly along and in frictional contact with the rod.

13. The orthopedic apparatus of claim 1, wherein the shaft is attached to the body at the first edge.

14. The orthopedic apparatus of claim 1, wherein the shaft is pivotally mounted to the body.

15. The orthopedic apparatus of claim 1, wherein the area extends through the body.

16. A body for an orthopedic apparatus comprising:

an area extending through the body for receiving and retaining a connector rod and an engagement mechanism for frictional communication with the connector rod, the engagement mechanism moveable in the area between a first position for receiving a connector rod, and, a second position where the engagement mechanism wedges the connector rod in the area to lock the connector rod therein.

17. The body of claim 16, wherein the engagement mechanism defines at least a portion of the area.

18. The body of claim 16, additionally comprising a shaft including threading for engaging a bony structure.

19. A method for connecting a connector rod comprising:

obtaining an orthopedic apparatus comprising:

a shaft portion for engaging a bony structure, and,

a body in communication with the shaft portion, the body including an area for receiving and retaining a connector rod and an engagement mechanism for communication with a rod, the engagement mechanism moveable between a first position for receiving the rod, and, a second position where the rod is secured by a frictional contact in a locking engagement in the body;

placing at least the shaft portion into a bony structure;

inserting a connector rod into the receiving area of the body when the engagement mechanism is in the receiving position; and,

moving the engagement mechanism in the area to the second position to lock the connector rod in the area of the body.

20. The method of claim 19, wherein the bony structure includes a pedicle of a vertebrae.