Patent Description:
The present invention, which is defined in the appended claims, relates to a bone fixation clamp, which includes first and second clamp members, a stud, and a locking nut. The first clamp member extends from a first end to a second end along a curve corresponding to an outer surface along a first target portion of a bone. The first end includes an opening extending therethrough along an axis which, when the first clamp member is positioned along the first target portion in an operative configuration, extends adjacent to the bone. The second clamp member extends from a first end to a second end along a curve corresponding to an outer surface along a second target portion of the bone. The stud extends longitudinally from the first end of the second clamp member to a free end so that, when the second clamp member is positioned along the second target portion of the bone in the operative configuration, the stud is receivable within the opening of the first clamp member along the axis of the opening. The locking nut includes a threaded channel configured to threadedly engage a portion of the stud so that, when the first and second clamp members are in the operative configuration, the locking nut is threadable over the stud to fix the first and second clamp members over the bone, the locking nut including an anti-loosening feature which, when the locking nut is threaded over the stud, results in an interference with threading along the stud. The stud and the opening of the first clamp member are correspondingly sized and shaped so that the stud is non-rotatably receivable within the opening.

In an embodiment, the anti-loosening feature includes a deformable portion deforming to interfere with threading along the stud.

In an embodiment, the locking nut extends longitudinally from a first end to a second end, the locking nut including a pair of grooves extending into the first end, through a wall of the locking nut so that the threaded channel is open to an exterior of the locking nut via the pair of grooves.

In an embodiment, the pair of grooves are substantially diametrically positioned relative to one another.

In an embodiment, the deformable portion is defined via a first slit extending through the wall of the locking nut from a first one of the pair of grooves about a portion of a circumference of the locking nut and a second slit extending through the wall of the locking nut from an end of the first slit toward a the first end of the locking nut.

In an embodiment, the anti-loosening feature includes a reduced minor diameter along a first portion of the threaded channel relative to a minor diameter along a second portion of the threaded channel.

In an embodiment, the stud includes a flat along a length thereof and the opening of the first clamp member includes a corresponding flat surface therealong.

In an embodiment, a length of the stud is selected to correspond to a width of a bone being treated.

In an embodiment, the second clamp member includes an elongated slot extending therealong and therethrough from a bone-facing surface of the second clamp member which, when the second clamp member is in the operative configuration faces toward a bone, to a surface of the second clamp member opposing the bone-facing surface of the second clamp member.

In an embodiment, the elongated slot is open at the second end of the second clamp member to define a pair of prongs of the second clamp member.

In an embodiment, the second clamp member includes a connecting web connecting the pair of prongs along a portion of the elongated slot.

In an embodiment, the first clamp member includes a groove extending therealong, the groove sized and shaped to correspond to a bone plate so that, the first clamp member is mountable over a portion of a bone along which a bone plate is positioned.

In an embodiment, a portion of the first clamp member including the groove includes a connecting opening extending therethrough so that, when the connecting opening is aligned with a corresponding hole of a bone plate over which the first clamp member is mounted, a screw is insertable through the connecting opening and the hole of the plate to fix the first clamp member and the bone plate relative to one another.

The present disclosure also relates to a bone fixation system which includes the bone fixation clamp, wherein the stud includes a channel at the free end thereof, and an insertion device.

The insertion device includes a sleeve extending from a proximal end to a distal end and sized and shaped to be slidable insertable through the threaded channel of the locking nut and the opening of the first clamp member, the distal end configured to engage the channel of
the stud and the proximal end configured to engage the opening of the first clamp member so that, when the distal end of the sleeve engages the stud and the proximal end of the sleeve engages the first clamp member, second ends of the first and second clamp members are separated from one another by a distance greater than a width of the bone so that the fixation clamp is positionable about the bone.

In an embodiment, the channel of the stud includes a recess extending along a portion thereof.

In an embodiment, the distal end of the sleeve includes a plurality of fingers, one of the fingers including a protrusion extending laterally therefrom, the protrusion configured to be received within the recess of the stud so that the distal end of the sleeve engages the channel of the stud via a snap fit.

In an embodiment, the insertion device includes a rod longitudinally slidable within the sleeve, the rod movable between a locking position, in which the rod is received between the fingers to lock the protrusion within the recess and the sleeve relative to the second clamp member, and an unlocked configuration, in which the rod is moved proximally relative to the sleeve so that the fingers are permitted to mov radially inward relative to one another to disengage the sleeve from the channel of the stud.

In an embodiment, the proximal end of the sleeve includes a stop for engaging the first clamp member.

In an embodiment, the anti-loosening feature includes a deformable portion deforming to interfere with threading along the stud, the deformable portion defined via slits extending through a wall of the locking nut.

Further described but not part of the present invention is a bone fixation clamp which includes a first clamp member, a second clamp member, and a shoulder bolt. The first clamp member extends from a first end to a second end along a curve corresponding to an outer surface along a first target portion of a bone, the first end including a first opening extending therethrough along an axis which, when the first clamp is positioned along the first target portion in an operative configuration, extends adjacent to the bone.

The second clamp member extends from a first end to a second end along a curve corresponding to an outer surface along a second target portion of the bone, the first end of the second clamp member including a second opening extending therethrough along an axis so that, in the operative configuration, axes of the first and second openings are substantially coaxially aligned, the second opening including a threading therealong, the second opening including a deformable portion; and.

The shoulder bolt is configured to fix the first and second clamp members relative to one another over a bone, the shoulder bolt including a shoulder and a shaft sized and shaped to be slidably inserted through the first opening, a portion of the shaft including a threading for engaging the thread of the second opening, the deformable portion deforming to interfere with the threading of the shaft.

In an embodiment (not falling under the scope of the present invention), a threaded portion of the shaft of the shoulder bolt is connected to the shoulder via an unthreaded portion.

In an embodiment (not falling under the scope of the present invention), the deformable portion is defined via slits extending through a wall of the second opening.

In an embodiment (not falling under the scope of the present invention), the shoulder is configured to engage a portion of the first opening so that, when the shoulder abuts the first opening and the shoulder bolt is tightened relative to the second clamp member, the first and second clamp members are drawn toward one another.

The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present invention relates to the treatment of fractured bones and, in particular, relates to a system for stabilizing a fractured or otherwise damaged bone by securing a bone fixation device to an outer surface thereof. The exemplary embodiments describe a fixation system comprising a fixation clamp which, in one embodiment, may be used in conjunction with other fixation devices such as, for example, a bone plate, to treat periprosthetic fractures of a long bone.

The exemplary fixation clamp is comprised of a first clamp member and a second clamp member configured to be coupled to one another so that, when coupled, the fixation clamp is mounted over the bone plate and extends about a periphery of the bone to provide stability and/or support to the bone. In one embodiment, the first and second clamp members are coupled when the first clamp member a stud of the second clamp member is received within an opening of the first clamp member and a locking nut is threaded over the stud so that the first and second clamp members are fixed relative thereto. The locking nut includes an anti-loosening feature preventing post-operative loosening thereof. In particular, the locking nut is plastically deformable, such that when the locking nut is threaded over the stud, the locking nut elastically deforms and maintains tension on the threads, thus creating an interference with threads of the stud to lock the nut relative thereto. It will be understood by those of skill in the art that the fixation clamp described herein may be used in conjunction with any of a variety of fixation devices to treat any of a variety of bones.

As shown in <FIG>, a fixation system <NUM> according to an exemplary embodiment of the present disclosure comprises a fixation clamp <NUM> including a first clamp member <NUM> and a second clamp member <NUM> couplable to one another so that, when coupled to one another in an operative configuration, the fixation clamp <NUM> extends about a portion of a periphery of a long bone to stabilize, for example, a Periprosthetic fracture. It will be understood by those of skill in the art that the fixation clamp <NUM> may be used in conjunction with other bone fixation devices such as, for example, a bone plate <NUM> configured to be positioned along a portion of a length of the bone.

In one embodiment, the first clamp member <NUM> extends from a first end <NUM> to a second end <NUM> along a curve substantially corresponding to a curve of a portion of an outer surface of a portion of bone on which the clamp is to be positioned. The second member <NUM> also extends from a first end <NUM> to a second end <NUM> along a curve substantially corresponding to an outer surface a portion of the bone it is to contact when positioned as desired. The first ends <NUM>, <NUM> of the first and second clamp members <NUM>, <NUM> are configured to be coupled to one another so that, in the operative configuration, the coupled first and second clamp members <NUM>, <NUM> to one another to extend about a portion of a periphery of the bone. In one embodiment, the first end <NUM> of the first clamp member <NUM> includes an opening <NUM> extending therethrough.

The opening <NUM> is sized, shaped and configured to receive a stud <NUM> extending from the first end <NUM> of the second member <NUM> through the opening <NUM> to couple the first and second clamp members <NUM>, <NUM> to one another. A locking nut <NUM> including an anti-loosening feature <NUM> is configured to be threaded over an end of the stud <NUM> to lock the first and second clamp members <NUM>, <NUM> relative to one another. The fixation system <NUM> also comprises an insertion device <NUM> which hold the first and second clamp members <NUM>, <NUM> relative to one another to facilitate insertion of the fixation clamp <NUM> into a desired position about the bone.

As described above, the fixation clamp <NUM> includes the first and second clamp members <NUM>, <NUM> coupled to one another via the stud <NUM> and locking nut <NUM>. As shown in <FIG>, the first clamp member <NUM> extends from the first end <NUM> to the second end <NUM> and has curve that corresponds to, for example, a portion of a surface of a lateral portion of the bone. In particular, in one embodiment, a bone-facing surface <NUM> of the first clamp member <NUM> is configured to extend, in the operative configuration, about a portion of a lateral surface of the bone. The first clamp member <NUM> may also include a recess <NUM> along the bone-facing surface <NUM> sized and shaped to correspond to the bone plate <NUM> so that the first clamp member <NUM> is mountable over the bone plate <NUM> in the operative configuration.

The first clamp member <NUM> also includes a connection screw hole <NUM> extending through the first clamp member <NUM> from a surface <NUM> which, in the operative configuration faces away from the bone, to the bone-facing surface <NUM>. The connection screw hole <NUM> extends through a portion of the first clamp member along which the recess <NUM> extends so that, when the first clamp member <NUM> is mounted over the bone plate <NUM>, a connection screw is insertable through the connection screw hole <NUM> to interface with and engage a screw-receiving opening of the bone plate <NUM>. A connection screw through the connection screw hole <NUM> therefore fixes the fixation clamp <NUM> relative to the bone plate <NUM> and/or the bone.

In one embodiment, the first clamp member <NUM> also includes a pair of bone fixation element receiving holes <NUM>. Each of the bone fixation element receiving holes <NUM> extends along an axis from the surface <NUM> to the bone-facing surface <NUM> and is configured to receive a bone fixation element (e.g., a bone screw) therein to fix the first clamp member <NUM> relative to the bone. Each of the bone fixation element receiving holes <NUM> extends through a portion <NUM> of the first clamp member <NUM> at the second end <NUM> and is connected to a remaining portion <NUM> of the first clamp member <NUM> via a bending zone <NUM>. In one embodiment, the bending zone <NUM> is defined via a reduced thickness of the first clamp member <NUM> at the bending zone.

In particular, a distance between the surface <NUM> and the bone facing surface <NUM> at the bending zone <NUM> is reduced relative to a thickness of the first clamp member <NUM> along other portions thereof so that the portion <NUM> of the first clamp member <NUM> including the bone fixation element holes <NUM> is bendable relative to the remaining portion <NUM> of the first clamp member <NUM> to specifically configure a shape of the first clamp member <NUM> to a target portion of the bone.

As would be understood by those skilled in the art, the bone fixation element receiving holes <NUM> may be configured to receive any of a variety of different types of bone screws. For example, in one embodiment, one or more of the bone fixation element receiving holes <NUM> may be a variable angle hole configured to receive a variable angle screw therein at a user-selected angle within a predetermined range of permitted angulations relative to the axis of the bone fixation element receiving hole <NUM>.

In another example, one or more of the bone fixation element receiving holes may be a locking hole including threading along an interior surface thereof configured to engaging corresponding threading on the head of a bone screw. It will be understood by those of skill in the art that the bone fixation element receiving holes <NUM> may have any of a variety of configurations so long as the bone fixation element receiving holes <NUM> are configured to receive bone fixation elements (screws) therein. It will also be understood by those of skill in the art that although the exemplary embodiment shows and describes a pair of holes <NUM>, the first clamp member <NUM> may have any number of bone fixation element receiving holes <NUM> (one or more) and each bone fixation element holes <NUM> may have a different configuration from another one of the holes <NUM>.

As described above, the opening <NUM> extends through the first end <NUM> to connect the first end <NUM> of the first clamp member <NUM> to the first end <NUM> of the second clamp member <NUM>. In particular, the opening <NUM> is sized, shaped and configured to receive the stud <NUM> of the second clamp member <NUM>, as will be described in further detail below. The opening <NUM> extends along an axis which, when the first clamp member <NUM> is in the operative configuration extends along an exterior of the bone, adjacent to the bone so that a stud <NUM> inserted therein does not intersect the bone at any point. Generally, the axis of the opening <NUM> will not intersect the bone.

As shown in <FIG>, the second clamp member <NUM> extends from the first end <NUM> to the second end <NUM> and has a curve that corresponds to, for example, a curve of a surface of a portion of a medial side of the bone. In particular, in one embodiment, a bone-facing surface <NUM> of the second clamp member <NUM> is configured to extend about a portion of a lateral surface of the bone, in the operative configuration. As described above, the second clamp member <NUM> includes the stud <NUM> extending from the first end <NUM> to a free end <NUM> so that the stud <NUM> is receivable within the opening <NUM> of the first clamp member <NUM> to couple the first and second clamp members <NUM>, <NUM> together.

In one embodiment, as shown in <FIG>, the bone-facing surface <NUM> includes a plurality of laterally extending grooves <NUM> to define gripping features <NUM> extending along a length of the bone-facing surface <NUM>. In one embodiment, the gripping features <NUM> may be configured as ridges and/or teeth-like elements configured to improve a grip of the second clamp member <NUM> along the bone. It will be understood by those of skill in the art that a depth, size and configuration of the grooves <NUM> may be varied to define various gripping features having varying gripping structures. In another embodiment, as shown in <FIG>, rather than grooves <NUM>, a second clamp member <NUM>' may include one or more sharp teeth <NUM>' protruding from a bone-facing surface <NUM>' to grip a bone received therealong.

In one embodiment, the second clamp member <NUM> also includes an elongated slot <NUM> extending therethrough from a surface <NUM> which, when the fixation clamp <NUM> is in the operative configuration faces away from the bone, to the bone-facing surface <NUM> along a length of the second clamp member <NUM>. It will be understood by those of skill in the art that, if damage occurs, the slot <NUM> mitigates this damage to a periosteum of the bone by reducing an area of contact between the second clamp member <NUM> and surrounding soft tissue and blood vessels. In the embodiment shown in <FIG>, the elongated slot <NUM> is closed at the second end <NUM>. In other words, the elongates slot <NUM> extends along a portion of a length of the second clamp member <NUM>, but does not extend beyond either the first end <NUM> or the second end <NUM>.

It will be understood by those of skills in the art, however, that a configuration of the elongated may be varied. In another embodiment, as shown in <FIG>, a second clamp member <NUM>" includes an elongated slot <NUM>" that is open at the second end <NUM>" of the second clamp member <NUM>" to define two prongs <NUM>" of the second clamp member <NUM>". The two prongs <NUM>" may provide some flexibility when using a fixation clamp over a portion of a bone that has a varying diameter from a first point about which a first one of the prongs <NUM>" is positioned and a second point about which a second one of the prongs <NUM>" is positioned. In yet another example, as shown in <FIG>, an elongated slot <NUM>'" of a second clamp member <NUM>'" is similarly open at a second end <NUM>'" to define two prongs <NUM>'". The two prongs <NUM>'", however, are connected to one another via a connecting web <NUM>'" extending across the elongated slot <NUM>'". The connecting web <NUM>'" may be positioned along any point along a length of the elongated slot <NUM>'".

The stud <NUM> extends from the first end <NUM> of the second clamp member <NUM> so that, when the first and second clamp members <NUM>, <NUM> are in the operative configuration, the stud <NUM> is received within correspondingly sized and shaped opening <NUM> of the first clamp member <NUM> along the axis of the opening <NUM>. According to the present invention, the stud <NUM> and the opening <NUM> are keyed relative to one another so that the stud <NUM> is non-rotatably received within the opening <NUM>. For example, the stud <NUM> may include a flat <NUM> extending along a length thereof for engaging a corresponding flat surface of the opening <NUM>. The stud includes a threaded portion <NUM> along the free end <NUM>. In one embodiment, the threaded portion <NUM> is connected to the first end <NUM> of the second clamp member <NUM> via an unthreaded portion <NUM>. In this embodiment, the flat <NUM> extends along both the unthreaded portion <NUM> and threads of the threaded portion <NUM>.

The stud <NUM> also includes a channel <NUM> extending into the free end <NUM> along a portion of a length thereof for receiving and engaging a portion of the insertion device <NUM>. In one embodiment, as shown in <FIG>, the channel <NUM> may also be keyed to the portion of the insertion device <NUM> to be received therein, including, for example, a flat <NUM> along a portion of a surface <NUM> of the channel <NUM>. The flat <NUM> facilitates a non-rotatable engagement with the insertion device <NUM>. In one embodiment, as shown in <FIG>, the surface <NUM> of the channel <NUM> includes a recess <NUM> extending into a portion thereof for engaging a corresponding portion of the insertion device <NUM>. As will be described in further detail below, the insertion device <NUM> may be inserted through the opening <NUM> of the first clamp member <NUM> to engage the channel <NUM> of the stud <NUM> to hold the first and second clamp members <NUM>, <NUM> relative to one another so that a surgeon or other user does not inadvertently lose a grip on either the first clamp member <NUM> and/or the second clamp member <NUM> during insertion of the fixation clamp <NUM> over the bone.

As described above, the locking nut <NUM> is configured to be threaded over the stud <NUM>. As shown in <FIG>, the locking nut <NUM> includes a threaded channel <NUM> extending therethrough, the threaded channel <NUM> configured to engage the threaded portion <NUM> of the stud <NUM>. Thus, when the fixation clamp <NUM> is positioned about the bone, the locking nut <NUM> may be tightened relative to the stud <NUM> (i.e., rotated about the threaded portion <NUM> of the stud <NUM>) to draw the first and second clamp member <NUM>, <NUM> toward one another so that the first and second clamp members <NUM>, <NUM> are compressed over the bone and/or the bone plate <NUM>. A surface <NUM> of the locking nut <NUM> which, in the operative configuration, faces away from the second clamp member <NUM>, includes a pair of grooves <NUM> extending thereinto, through a wall <NUM> of the locking nut <NUM>. In one embodiment, the pair of grooves <NUM> extend through portions of the locking nut <NUM> that are substantially diametrically opposed to one another.

As described above, the locking nut <NUM> includes an anti-loosening feature <NUM> so that, as the locking nut <NUM> is tightened, the locking nut <NUM> is locked relative to the stud <NUM> to prevent post-operative loosening of the nut <NUM>. In one embodiment, the anti-loosening feature <NUM> includes a deformable portion <NUM> defined via a first slit <NUM> and a second slit <NUM> extending through the wall <NUM> of the locking nut <NUM>. In particular, the first slit <NUM> extends through the wall <NUM> from a first one of the pair of grooves <NUM>, so that the first slit <NUM> is open to the first one of the grooves <NUM>, about a portion of a circumference of the locking nut <NUM> to an end <NUM> proximate, but not open to a second one of the pair of grooves <NUM>. The second slit <NUM> extends from the end <NUM> of the first slit <NUM> toward the surface <NUM> of the locking nut <NUM> which, in the operative configuration, faces away from the second clamp member <NUM>.

In one embodiment, the first slit <NUM> extends substantially midway between the surface <NUM> and an opposing surface <NUM>. The first and second slits <NUM>, <NUM> permit deformation of the deformable portion188 toward the second clamp member <NUM>, as the locking nut <NUM> is tightened about the stud <NUM>. Such a deformation results in an interference between the locking nut <NUM> and the threaded portion <NUM>, which locks the locking nut <NUM> thereover to prevent post-operative loosening. Although the exemplary embodiment shows and describes one deformable portion <NUM>, it will be understood by those of skill in the art that the locking nut <NUM> may also include a second deformable portion extending along a substantially opposing portion of the locking nut <NUM>.

In one embodiment, as shown in <FIG>, the insertion device <NUM> includes a sleeve <NUM> and an elongated rod <NUM> longitudinally slidable therein. The sleeve <NUM> extends longitudinally from a proximal end <NUM> to a distal end <NUM> and is sized and shaped to be slidably inserted through both the threaded channel <NUM> of the locking nut <NUM> and the opening <NUM> of the first clamp member <NUM>. The distal end <NUM> is sized and shaped to be received within the channel <NUM> at the free end <NUM> of the stud <NUM>. In one embodiment, the distal end <NUM> of the sleeve <NUM> includes a plurality of fingers <NUM> which flex radially inward as the distal end <NUM> is received within the channel <NUM>.

One of the fingers <NUM> may include a protrusion <NUM> extending laterally therefrom so that, when the protrusion <NUM> is received within the recess <NUM> of the channel <NUM>, the fingers <NUM> revert to their initial configuration so that the fingers <NUM> "snap" into position within the channel <NUM>. The rod <NUM> is sized and shaped to be received within the sleeve <NUM> so that, when the rod is <NUM> is moved distally relative to the sleeve <NUM> so that the rod <NUM> is received between the plurality of fingers <NUM>, the fingers <NUM> are locked in an engaged configuration within the channel <NUM> and are prevented from being inadvertently disengage therefrom. In another embodiment, the fingers <NUM> may be biased toward a radially inward position so that moving the rod <NUM> so that the rod <NUM> is received between the fingers <NUM> moves the fingers <NUM> radially outward so that the protrusion <NUM> engages the recess <NUM>. It will be understood by those of skill in the art that the terms proximal and distal as used herein to described portions of the insertion device <NUM>, are intended to refer to a direction toward (proximal) and away (distal) from the surgeon or other user of the device.

When it is desired to assemble the fixation clamp <NUM> for insertion about a bone, the locking nut <NUM> is positioned over the first opening <NUM> of the first clamp member <NUM> so that the distal end <NUM> of the sleeve <NUM> is inserted first through the locking nut <NUM>, then through the opening <NUM> so that the distal end <NUM> may engage the channel <NUM> of the stud <NUM>, as described above. Once the distal end <NUM> of the insertion device <NUM> is fixed relative to the second clamp member <NUM> by moving the rod <NUM> distally within the sleeve <NUM> to move the plurality of fingers <NUM> radially outward, the first clamp member <NUM> is permitted to be slid proximally along the sleeve <NUM>, until the surface <NUM> of the locking nut <NUM> abuts a stop <NUM> at the proximal end <NUM> of the sleeve <NUM>. The first clamp member <NUM> is movable along the sleeve <NUM> while the second clamp member <NUM> is rigidly fixed to the sleeve <NUM> and the rod <NUM>, the rod <NUM> being threaded into the second clamp member <NUM>.

When the first clamp member <NUM> is drawn proximally so that the locking nut <NUM> abuts the stop <NUM>, second ends <NUM>, <NUM> of the first and second clamp members <NUM>, <NUM> are separated from one another via a distance greater than a width of the bone (e.g., a maximum distance between a medial side of the bone and a lateral side of the bone) so that the fixation clamp <NUM> may be slid over the bone into a position about the bone. Once the fixation clamp <NUM> has been positioned about the bone, the first clamp member <NUM> and the locking nut <NUM> may be moved distally along the insertion device <NUM> so that the locking nut <NUM> may be threaded over the threaded portion <NUM> of the stud <NUM>. The rod <NUM> is drawn proximally relative to the sleeve <NUM> so that the plurality of fingers <NUM> revert to their biased configuration and the distal end <NUM> of the sleeve <NUM> is disengaged from the stud <NUM> so that the insertion device <NUM> may be removed from fixation clamp <NUM>. As described above, the locking nut <NUM> is tightened over the threaded portion <NUM> to draw the first and second clamp members <NUM>, <NUM> closed toward one another, thereby fixing the fixation clamp <NUM> over the bone.

It will be understood by those of skill in the art that widths of bones may vary from patient to patient. Thus, a variety of sizes of fixation clamps <NUM> may be available so that a suitable fixation clamp may be selected based on the width of the patient bone. In one embodiment, a length of the stud <NUM> of the fixation clamp <NUM> is selected to correspond to the width of the bone of the patient being treated. It will be understood by those of skill in the art that a size and curvature of the first and second clamp members <NUM>, <NUM> may also vary depending on a size of the bone being treated.

As shown in <FIG>, a locking nut <NUM> according to another exemplary embodiment may be used in the system <NUM>, as described above, in place the locking nut <NUM>. The locking nut <NUM> is substantially similar to the locking nut <NUM>, including a threaded channel <NUM>, via which the locking nut <NUM> threadedly engages the threaded portion <NUM> of the stud <NUM>, and an anti-loosening feature <NUM> which engages the threaded portion <NUM> in such a manner as to prevent a post-operative loosening relative thereto.

Rather than a deformable portion as described with the respect to the locking nut <NUM>, however, the anti-loosening feature <NUM> is configured as a reduced minor diameter along a first portion <NUM> of the threaded channel <NUM> extending from a first surface <NUM> of the locking nut <NUM> which, in an operative configuration, faces away from the second clamp member <NUM>, relative to a second portion <NUM> of the threaded channel <NUM>, which extends from the first portion <NUM> to a second surface <NUM> opposing the first surface <NUM>. The minor diameter is defined via radially innermost edges of the threaded channel <NUM>.

In one example, the minor diameter of the first portion <NUM> may be approximately <NUM> while the minor diameter of the second portion <NUM> may be approximately <NUM>. It will be understood by those of skill in the art, however, that the minor diameter of the first and second portions <NUM>, <NUM> of the threaded channel <NUM> may have any of a variety of configurations so long as the minor diameter of the first portion <NUM> is smaller than the diameter of the second portion <NUM>. In one embodiment, the first portion <NUM> extends along four turns of threading of the threaded channel <NUM> so a transition in the minor diameter occurs after four turns from the first surface <NUM>. It will be understood by those of skill in the art that the reduced minor diameter along the first portion <NUM> provides increased friction with the threads of the stud <NUM> received therein to prevent backing out (e.g., loosening) of the locking nut <NUM> relative to the stud <NUM> of the fixation clamp <NUM>.

As shown in <FIG>, a fixation clamp <NUM> according to another exemplary embodiment (not falling under the scope of the present invention) may be substantially similar to the fixation clamp <NUM>, as described above with respect to the system <NUM>, including a first clamp member <NUM> and a second clamp member <NUM> that are couplable relative to one another to extend about and engage a long bone. Rather than a locking nut and stud, however, the fixation clamp <NUM> further includes a shoulder bolt <NUM> for coupling the first and second clamp members <NUM>, <NUM>.

The first clamp member <NUM> is substantially similar to the first clamp member <NUM>, extending from a first end <NUM> to a second end <NUM> along a curve corresponding to, for example, a lateral surface of the bone. Similarly to the first clamp member <NUM>, the first clamp member <NUM> includes an opening <NUM> extending through the first end <NUM> for coupling the first clamp member <NUM> to the second clamp member <NUM>. The second clamp member <NUM> is substantially similar to the second clamp member <NUM>, extending from a first end <NUM> to a second end <NUM> along a curve corresponding to, for example, a medial surface of the bone. The first end <NUM>, however, does not include a stud extending therefrom. Rather, the first end <NUM> include a threaded opening <NUM> extending therethrough for threadedly engaging a threaded portion <NUM> of the shoulder bolt <NUM>.

The threaded opening <NUM> includes an anti-loosening feature <NUM> which prevents a post-operative loosening of the shoulder bolt <NUM>. In one embodiment, the anti-loosening feature <NUM> is configured as a deformable portion <NUM> which deforms to cause an interference between threads of the shoulder bolt <NUM> and threads of the opening <NUM>. In one example, the deformable portion <NUM> is defined via a first slit <NUM> and a second slit <NUM> extending through a wall of the opening <NUM>. In one embodiment, the first slit <NUM> extends through the wall, from a first end <NUM> of the opening <NUM> toward a second end <NUM> of the opening <NUM>, to an end <NUM>. The second slit <NUM> extends from the end <NUM> of the first slit <NUM>, about a portion of a circumference of the opening <NUM>.

The shoulder bolt <NUM> includes the threaded portion <NUM> connected to a shoulder <NUM> via an unthreaded portion <NUM>. To coupled the first and second clamp members <NUM>, <NUM>, the threaded portion is inserted through the opening <NUM> of the first clamp member <NUM> and into the threaded opening <NUM> of the second clamp member <NUM> so that threaded portion <NUM> threadedly engages the threaded opening <NUM>. In particular, when the first and second clamp members <NUM>, <NUM> are positioned about the bone in a desired position, axes of the openings <NUM>, <NUM> are substantially coaxially aligned so that the shoulder bolt <NUM> may be inserted thereinto along the axes thereof.

Claim 1:
A bone fixation clamp (<NUM>), comprising:
a first clamp member (<NUM>) extending from a first end (<NUM>) to a second end (<NUM>) along a curve corresponding to an outer surface along a first target portion of a bone, the first end (<NUM>) including an opening (<NUM>) extending therethrough along an axis which, when the first clamp member (<NUM>) is positioned along the first target portion in an operative configuration, extends adjacent to the bone;
a second clamp member (<NUM>) extending from a first end to a second end along a curve corresponding to an outer surface along a second target portion of the bone;
a stud (<NUM>) extending longitudinally from the first end of the second clamp member (<NUM>) to a free end (<NUM>) so that, when the second clamp member (<NUM>) is positioned along the second target portion of the bone in the operative configuration, the stud (<NUM>) is receivable within the opening (<NUM>) of the first clamp member (<NUM>) along the axis of the opening (<NUM>); and
a locking nut (<NUM>) including a threaded channel (<NUM>) configured to threadedly engage a portion of the stud (<NUM>) so that, when the first and second clamp members (<NUM>, <NUM>) are in the operative configuration, the locking nut (<NUM>) is threadable over the stud (<NUM>) to fix the first and second clamp members (<NUM>, <NUM>) over the bone, characterized in that the locking nut (<NUM>) includes an anti-loosening feature (<NUM>) which, when the locking nut (<NUM>) is threaded over the stud (<NUM>), results in an interference with threading along the stud (<NUM>), and in that the stud (<NUM>) and the opening (<NUM>) of the first clamp member (<NUM>) are correspondingly sized and shaped so that the stud is non-rotatably receivable within the opening (<NUM>).