Patent Description:
Achieving bicortical engagement of screws can be problematic when fixing a bone having a peri-prosthetic fracture. In this type of fracture, the fracture line overlaps a previously-installed, underlying prosthesis. Typically, the prosthesis has an intramedullary stem for anchorage, and a head to replace an articulating end of the bone. The stem occupies a section of the medullary canal, thus obstructing a standard bicortical trajectory of bone screws.

Screw trajectories can be moved outside of the bone's medullary canal through the use of an attachment plate mounted over a fixation plate, as disclosed in <CIT>. <CIT> discloses a system including a compression plate and a cerclage cable for encircling the bone and securing the compression plate to the bone. The cable has a ball or other structure functioning as a stop at one end, and a free end. The attachment plate is secured separately to the fixation plate and bone, which limits the number of positions at which the attachment plate can be installed. Variations in bone size and geometry can make securing the attachment plate to bone unreliable, thereby reducing the number of positions even further.

The present invention relates to a system for fixing bone as claimed hereafter. Preferred embodiments of the invention are set forth in the dependent claims. Associated methods are also described herein to aid understanding of the invention, but these do not form part of the claimed invention.

In an exemplary system, the plate is an elongated plate configured to be disposed longitudinally on a bone. The retainer has a body interconnecting a pair of mounting regions. The body defines a recess, and each mounting region defines a first aperture and a second aperture. The retainer is configured to be mated with the plate to position a section of the plate in the recess such that the retainer straddles the plate. The first apertures are configured to define through-axes that are tangential to the bone, to enable use with a line including wire and/or cable, and each second aperture are configured to define a through-axis that extends through opposite sides of the bone while avoiding a medullary canal thereof, to enable use with a threaded fastener.

The present disclosure provides systems for bone fixation using a plate straddled by a retainer. In an exemplary system, the plate may be an elongated plate configured to be disposed longitudinally on a bone. The retainer may have a body interconnecting a pair of mounting regions. The body may define a recess, and each mounting region may define a first aperture and a second aperture. The retainer may be configured to be mated with the plate to position a section of the plate in the recess such that the retainer straddles the plate. The first apertures may be configured to define through-axes that are tangential to the bone, to enable use with a line including wire and/or cable, and each second aperture may be configured to define a through-axis that extends through opposite sides of the bone while avoiding a medullary canal thereof, to enable use with a threaded fastener.

An exemplary system for plate attachment to bone is provided. The system may comprise a plate configured to be disposed on a bone, and a retainer. The retainer may have a first mounting region opposite a second mounting region. The retainer may be configured to straddle the plate such that the first mounting region and the second mounting region project away from opposite lateral edges of the plate. Each of the first mounting region and the second mounting region may define an aperture. The system also may comprise a line and a sleeve. In exemplary embodiments, the line is a cable or wire. The line may be configured to extend from the aperture of the first mounting region to the aperture of the second mounting region, such that the retainer and the line collectively encircle a bone. The sleeve may be configured to be received on the line and crimped to lock the sleeve to the line.

Fixation of a bone having a peri-implant fracture (e.g., a peri-prosthetic fracture) can be challenging. The bone can be stabilized with a wider bone plate designed specifically for peri-prosthetic fractures. However, this bone plate cannot be customized readily for the needs of a given patient having a particular bone size and shape, fracture pattern, and implant. The bone alternatively can be fixed with a fixation plate and an attachment plate. The attachment plate fits over the fixation plate and is configured to be attached to bone with bone screws. However, due to variations in bone geometry, the bone screws often do not provide sufficient anchorage or miss the bone completely.

The systems disclosed herein offer various advantages. For example, the surgeon has more options for attaching a bone plate to bone. Accordingly, the bone plate can be installed more efficiently and securely. Also or alternatively, the bone plate when attached to bone can have the stability of a wider plate but the footprint of a narrower plate.

Further aspects of the present disclosure are described in the following sections: (I) fixation system with plate and retainer, (II) methods not claimed of bone fixation and plate attachment and (III) composition of system components.

This section describes an exemplary bone fixation system <NUM> including a plate <NUM> and an encircling assembly <NUM> incorporating a plate-straddling retainer <NUM>; see <FIG>.

<FIG> and <FIG> show fixation system <NUM> attached to a distal portion of a femur <NUM> having at least one discontinuity, such as at least one fracture <NUM>, with plate <NUM> spanning the discontinuity. The system may be utilized to stabilize any suitable portion of any suitable bone. For example, the system may be attached to a bone having at least a portion of an implant <NUM> extending along a medullary canal thereof, and the implant, plate <NUM>, encircling assembly <NUM>, and/or retainer <NUM> may be located at mutually overlapping positions along the bone, such as overlapping positions in a shaft region of the bone (also see Section II).

Plate <NUM> may have any suitable structure and orientation on bone. The plate may be elongated and oriented longitudinally on the bone, as shown. Plate <NUM> may have an inner surface <NUM> (also called a bone-facing surface or bottom surface) opposite an outer surface <NUM> (also called a top surface). The plate also may have a pair of lateral edges <NUM> (also called lateral sides) located intermediate surfaces <NUM>, <NUM> and extending between opposite ends of the plate. The plate may define a plurality of apertures <NUM> to receive fasteners, such as bone screws that attach the plate to bone. Each fastener may be a linear fastener, which may have one or more external threads to engage the plate or bone (or both). Each aperture <NUM> may extend through plate <NUM> from inner surface <NUM> to outer surface <NUM>. Each of the fasteners placed into an aperture <NUM> independently may or may not lock to the wall of the aperture, such as via an internal thread <NUM> of the aperture. Each aperture independently may be circular or elongated transversely (e.g., orthogonally) to a through-axis of the aperture, among others. Other exemplary fasteners for engagement of plate <NUM> include pins, pegs, rivets, staples, wires, retainer <NUM>, or the like. Any suitable number of apertures <NUM>, such as only a subset of the apertures, may receive fasteners that connect plate <NUM> to bone.

Fixation system <NUM> may include one or more retainers <NUM>, each of which may be installed over plate <NUM> at the discretion of the surgeon. Each retainer <NUM> may be positioned at a selected position along a centerline <NUM> of plate <NUM> to couple the plate to bone at that position. (The centerline may be linear or curved. ) The position may be selected from a continuous range of permitted axial positions at which the retainer can be installed. The retainer may be introduced where local attachment of the plate to the bone via fasteners placed into apertures <NUM> is not feasible, not effective, needs reinforcement, or the like. The retainer may be described as a supplemental plate or an attachment plate.

Each retainer <NUM> may have a body <NUM> and a pair of mounting regions 78a, 78b interconnected by the body (see <FIG>). The mounting regions may be located opposite one another on opposite sides of body <NUM>. The body may be contoured to be complementary to a section of the plate by defining a recess <NUM> (interchangeably called a receiving space) in the underside of the body. The recess allows the retainer to be mated with plate <NUM>, such that body <NUM> receives a section of the plate and straddles the plate. Once the retainer is mated with the plate, body <NUM> may be located on/adjacent, and optionally in contact with, outer surface <NUM> and lateral edges <NUM> to cover a portion of each.

The cross-sectional shape of plate <NUM> may be sufficiently uniform along at least a portion of its length to allow the retainer to be mated with the plate at each of a plurality of alternative longitudinal positions along the plate, and/or to allow the retainer, once mated, to slide longitudinally along the plate to a desired position. (An alternative longitudinal position of the retainer is shown in phantom outline in <FIG>. ) Mounting regions 78a, 78b of the mated retainer may be disposed respectively on opposite lateral sides of plate <NUM>, and may project away from respective lateral edges <NUM> of plate <NUM>, and/or in opposite circumferential directions on the bone.

Retainer <NUM> may be secured to bone via mounting regions 78a, 78b to couple plate <NUM> to bone (see <FIG>). Each mounting region may be attached to bone via (a) at least one threaded fastener <NUM> (which be linear and/or threaded externally), (b) a spanning member <NUM> extending from one mounting region to the other mounting region such that the spanning member and the retainer cooperatively form encircling assembly <NUM> that encircles plate <NUM> and the bone, or (c) both.

Each mounting region 78a, 78b may define one or more apertures to receive fastener(s) <NUM> and/or spanning member <NUM>. The mounting region may define at least one aperture <NUM> to operatively receive threaded fastener(s) <NUM> (see <FIG>). Each aperture <NUM> may have an internal thread for threaded engagement with fastener <NUM>. For example, fastener <NUM> may have an externally-threaded trailing portion <NUM> that locks the fastener to aperture <NUM>. Alternatively, the fastener may not lock to the aperture because the aperture lacks an internal thread and/or the fastener lacks a complementary external thread. In some embodiments, the system may include a first set of fasteners that lock to apertures <NUM> via the internal thread thereof, and a second set of fasteners that do not lock to the apertures. The second set of fasteners allow the surgeon to choose the trajectories followed by the fasteners into the bone. In any event, fastener <NUM> may have an externally threaded shaft <NUM> to engage bone under the mounting region. The diameter of shaft <NUM> may be less than that of trailing portion <NUM>. The mounting region also or alternatively may define an aperture <NUM> sized to receive and engage part of spanning member <NUM>.

The spanning member may include a line <NUM> and a pair of stop members 96a, 96b. The line may be a length of cable/wire or the like that is capable of following a circumferential path around the bone between mounting regions 78a, 78b. The line may be sufficiently flexible to conform generally to a convex contour of the bone. Each stop member may be any structure having a fixed or fixable position along the line, and sized to prevent passage, completely through aperture <NUM>, of the stop member (and the attached line). One of the stop members may be pre-attached to the line during manufacture (e.g., by crimping, welding, press-fitting, or the like), or both stop members may be attached to the line intra-operatively, among others. The stop members may or may not have the same structure (e.g., may or may not be substantially identical to one another). In some embodiments, at least one of the stop members may be a sleeve through which the line can extend. The sleeve may be deformable (i.e., crimpable) to lock (firmly attach) the sleeve to the line, such that the sleeve can no longer slide along the line.

<FIG> show retainer <NUM> mated with plate <NUM>. A section of plate <NUM> is located in recess <NUM> of retainer <NUM>. The retainer has a top portion <NUM> positioned over outer surface <NUM> of the plate, and has lateral portions <NUM> positioned adjacent lateral edges <NUM> of the plate. The retainer and plate may define complementary mating structures that slidably connect the retainer and plate to one another via a snap-fit connection upon mating (and before the retainer is attached to bone with fasteners <NUM> and/or spanning member <NUM>). More specifically, the mating structures may include a pair of longitudinal tracks <NUM> provided by plate <NUM> that resist removal of retainer <NUM>, when the retainer is urged away from the plate normal to the outer surface of the plate, while guiding movement of the retainer along the plate, parallel to centerline <NUM> (see <FIG>, <FIG>, and <FIG>). In the depicted embodiment, tracks <NUM> are furrows defined by lateral edges <NUM> of plate <NUM>, and retainer <NUM> defines complementary protrusions <NUM>, such as ridges, on lateral portions <NUM> in recess <NUM>. In other embodiments, the tracks may be formed by protrusions, such as ridges, on plate <NUM>, and complementary indentations may be defined in corresponding lateral wall portions of recess <NUM>. The retainer (and/or the plate) may deform as the retainer is being mated with the plate, to allow the complementary mating structures to be placed into operative interaction. Accordingly, the retainer when first mated with the plate, may provide haptic and/or audible feedback to the surgeon when mating has been completed. The retainer also may need to be deformed to separate the complementary mating structures from one another, thereby permitting removal of the retainer from the plate. In some cases, a tool may be utilized to apply sufficient force for removal.

<FIG> illustrate how the retainer can be coupled to femur <NUM> (or another bone) using spanning member <NUM> (<FIG>) and/or fasteners <NUM> (<FIG>), while avoiding implant <NUM> in medullary canal <NUM> of the femur. <FIG> compare through-axes <NUM> defined by apertures <NUM> used for spanning member <NUM>, with through-axes <NUM> defined by apertures <NUM> for threaded fasteners <NUM>. Axes <NUM> may be tangential with respect to the bone, to guide line <NUM> of spanning member <NUM> in a circumferential direction on the bone. This arrangement helps to prevent the line from getting kinked. The term "tangential" for an axis in relation to a bone means substantially following a tangent defined by the bone, such that the axis passes close to the surface of the bone, either missing the bone completely or only passing through the bone peripherally. In contrast, axes <NUM> may be oriented relatively more radially with respect to the bone, and may pass through opposite sides of the bone, to guide fastener <NUM> into the bone, optionally while missing medullary canal <NUM> (and thus implant <NUM>).

The respective orientations of axes <NUM>, <NUM> also may be contrasted by their relationships to a radial plane <NUM> and a tangential plane <NUM> (see <FIG>). Radial plane <NUM> is centered between mounting regions 78a, 78b and oriented at least generally radially with respect to the bone. The radial plane is parallel to (and optionally contains) an extension axis <NUM> on which plate <NUM> extends through retainer <NUM>, and may bisect the retainer. Tangential plane <NUM> is orthogonal to radial plane <NUM> and tangential to the bone. Through-axes <NUM> and <NUM> may intersect radial plane <NUM> on opposite sides of tangential plane <NUM> from one another. More specifically, through-axes <NUM> may intersect radial plane <NUM> above the retainer, and through-axes <NUM> may intersect radial plane <NUM> below the retainer. The terms "above" and "below" as used herein are defined with the outer/top surface of the plate and retainer facing upward. More specifically, "above" a given element means at a higher elevation than the element, and "below" means at a lower elevation than the element.

The orientation of axes <NUM>, <NUM> alternatively may be contrasted in an orthogonal projection of the retainer onto a transverse plane <NUM> that is orthogonal to extension axis <NUM> (see <FIG>). In the projection, axes <NUM> converge above retainer <NUM> (as in <FIG>), while a pair of axes <NUM> from respective mounting regions 78a, 78b converge below retainer <NUM> (as in <FIG>).

A pair of axes <NUM> or <NUM> may or may not lie in the same plane. Axes <NUM> may be coplanar with one another, optionally lying in a plane that is parallel to transverse plane <NUM>. Each at least generally converging pair of axes <NUM> also may be coplanar with one another, again optionally lying in a plane that is parallel to transverse plane <NUM>. In contrast, a pair of axes <NUM> and <NUM> defined by respective apertures <NUM>, <NUM> of the same mounting region 78a or 78b, when projected orthogonally onto transverse plane <NUM>, may be oblique to one another in the projection. The pair of axes may form an angle between one another in the projection of at least about <NUM>, <NUM>, <NUM>, or <NUM> degrees, among others.

<FIG> show various views of retainer <NUM>, which may have reflectional symmetry. As discussed above, the retainer may have a body <NUM>, defining recess <NUM>, and mounting regions 78a, 78b projecting from opposite sides of the body. The body may be generally U-shaped in end view and cross-section (see <FIG>), with a top portion <NUM> interconnecting a pair of depending legs <NUM>. Each mounting region may include a foot formed on the end of each leg and configured to be disposed on bone. Each leg and attached mounting region (or foot) form a lateral portion <NUM> of the retainer (also see <FIG>). Each foot may be divided by openings, such as slits <NUM>, into a plurality of mounting sections or tabs 124a, 124b, 124c, each defining a respective aperture (i.e., aperture <NUM> or <NUM>) (see <FIG>). In the depicted embodiment, mounting tab 124b to receive line <NUM> is located between a pair of mounting tabs 124a, 124c to receive respective fasteners <NUM>. The presence of more than one mounting tab in the mounting region can be advantageous because this configuration allows the tabs to be deformed independently of one another (e.g., to adjust the orientation of at least one tab), and to have a different resistance to deformation from one another. For example, in the depicted embodiment, each mounting tab 124b is strengthened and stabilized by a pair of ribs <NUM> that protrude from the outer side of each leg and extend continuously to the mounting tab (see <FIG>). Ribs <NUM> also or alternatively may form opposite sides of a channel <NUM> that joins aperture <NUM>. The channel may guide placement of a stop member 96a or 96b into aperture <NUM> during installation of the retainer and/or limit excessive movement of the stop member.

<FIG> further illustrate the different orientations of apertures <NUM> and <NUM>. Each mounting region or foot has at least one inner surface region <NUM> to face bone, and at least one lateral surface regions <NUM> forming a lateral edge of the retainer. The bottom end of each aperture <NUM> may be formed at least predominantly in an inner surface region <NUM>, while the bottom end of each aperture <NUM> may be formed at least predominantly in a lateral surface region <NUM>.

Retainer <NUM> may have a window <NUM> defined as a large opening by top portion <NUM>. The presence of the window increases the flexibility of the retainer, to facilitate deformation of the retainer that may be needed when the retainer is mated with the plate (see above). Alternatively, the window may be omitted to increase the strength of the retainer (see <FIG>).

<FIG> show further aspects of stop members 96a, 96b and exemplary relationships between the stop members, retainer <NUM>, and line <NUM>. Each stop member may be sized to prevent complete passage of the stop member through aperture <NUM>. One or both stop members may be a sleeve defining a through-bore <NUM> sized in correspondence with the diameter of line <NUM>, to allow the line to slide through the sleeve. The stop member may have an enlarged bearing portion <NUM>, which may be spherical, to contact a complementary wall region <NUM> of aperture <NUM>. The sleeve and retainer may be configured to permit bearing portion <NUM> to slide on wall region <NUM> of aperture <NUM> through a range of orientations of a long axis <NUM> defined by the stop member. The stop member also may have a crimp portion <NUM> at which the stop member is configured to be crimped. The crimp portion may have a smaller maximum diameter than bearing portion <NUM>. The crimp portion may be non-spherical, and may be elongated and/or cylindrical. In some embodiments, as described further below, each stop member may be installed in either of two opposite orientations on line <NUM> and/or the stop members may be inverted with respect to one another when installed.

<FIG> show an exemplary structure for aperture <NUM>. The aperture may have concave spherical wall region <NUM> disposed outward (along through-axis <NUM>) of a cylindrical region <NUM>, which, like aperture <NUM>, may have an internal thread <NUM>. (The presence of an internal thread may permit aperture <NUM> to be used alternatively with fasteners <NUM> and spanning member <NUM>. Channel <NUM> may extend continuously from wall region <NUM> and may be cylindrical, with the same radius of curvature as wall region <NUM>.

<FIG> also illustrate exemplary configurations for stop members 96a and 96b in respective mounting regions 78a and 78b of retainer <NUM>. The stop members may be inverted relative to one another, as shown, to position crimp portion <NUM> below (<FIG>) or above (<FIG>) bearing portion <NUM>. In other embodiments, the stop members may not be identical to one another.

Stop member 96a (or a different stop member) may be pre-attached to line <NUM>, such as by deforming crimp portion <NUM>, optionally before either end region of the line is passed through aperture <NUM>. The stop member may be oriented such that crimp portion <NUM> is farther than bearing portion <NUM> from a first end region <NUM> of the line, and closer than bearing portion <NUM> to a longitudinally central section of the line. Accordingly, in the installed configuration of <FIG>, bearing portion <NUM> is in contact with spherical wall region <NUM> of aperture <NUM> above crimp portion <NUM>. The crimp portion may be disposed adjacent cylindrical region <NUM> of aperture <NUM> and may project out of the lower end of the aperture. The orientation of stop member 96a minimizes tissue irritation.

Stop member 96b may be attached to line <NUM> after stop member 96a is located in corresponding aperture <NUM>. A second, opposite end region <NUM> of line <NUM> may be fed around the bone, and through aperture <NUM> and stop member 96b. The line may be tensioned, and crimp portion <NUM> deformed to lock the stop member to the line. Line <NUM> then may be cut to remove at least part of second end region <NUM>, if any, that protrudes from crimp portion <NUM> of stop member 96b.

Each stop member may or may not be permitted to pivot about a center of curvature of bearing portion <NUM>. This pivotal motion permits line <NUM> to more closely follow the contour of the bone near the retainer and allows the stop member to be operatively engaged with the wall of aperture <NUM> in a range of orientations. In <FIG>, the outer diameter of crimp portion <NUM> may be only slightly less than the inner diameter of aperture <NUM> at cylindrical region <NUM>, to restrict pivotal motion of the bearing portion, or may be significantly less to permit pivotal motion. In <FIG>, the diameter of line <NUM> is significantly less than the corresponding inner diameter of aperture <NUM> at cylindrical region <NUM>, allowing pivotal motion of stop member 96b to change the orientation at which line <NUM> extends from retainer <NUM>.

This section describes exemplary methods of bone fixation and plate attachment implemented with the systems of the present disclosure. The method steps of this section may be performed in any suitable order and combination, and may be modified by, or combined with, any other suitable aspects of the present disclosure.

A bone to be fixed may be selected. The method may be performed on any suitable bone, and on any suitable portion thereof, such as a proximal portion, a central portion, a distal portion, or a combination thereof, among others. Exemplary bones that may be selected include a long bone of a limb, such as a femur, tibia, fibula, humerus, radius, or ulna. The bone may have any suitable discontinuity or structural weakness, such as at least one fracture, cut, nonunion, or the like. The bone may contain at least a portion of an implant in a medullary canal of the bone. The implant may be a prosthesis this is attached to the bone, replaces a missing portion of the bone, and/or provides an articulation surface of a joint. The implant alternatively may be an intramedullary nail.

An incision may be created through overlying soft tissue to access the selected bone. The bone may be manipulated to reposition bone fragments (e.g., to approximate the relative anatomical location of the fragments), such as to set a fracture. Manipulation of bone fragments may be performed before and/or after the incision is created.

A plate may be selected for stabilizing the bone. The plate may be elongated and/or may have any combination of the plate features described elsewhere herein. The plate may be described as a main plate. The plate may be placed through the incision and onto the bone, such that the plate spans a discontinuity in the bone.

The plate may be attached to the bone with one or more fasteners, such as at least one screw, peg, pin, wire, cable, rivet, and/or the like. Each fastener independently may extend into bone directly under the plate from an aperture (a through-hole) thereof (e.g., in the case of a screw, peg, or pin), or may extend over the plate and around the bone (e.g., in the case of a wire or cable). The fastener may engage the plate, and may or may not lock to the plate, such as via threaded engagement. In some embodiments, the plate may be attached provisionally to the bone with at least one tool, such as at least one clamp, before the plate is attached with the one or more fasteners and/or one or more encircling assemblies including a retainer (see below).

At least one retainer may be selected for attaching the plate to the bone, and a suitable longitudinal position for each retainer along the plate may be selected. The number and position(s) of retainers to be used in the method may be selected at any suitable time, such as before and/or after attaching the plate to the bone with one or more fasteners (and/or one or more tools) that engage the plate. In some embodiments, positions for retainers may be based on one or more locations at which the one or more fasteners are engaged with the plate, and may be offset along the plate from these locations, namely, at longitudinal positions of the plate at which no fasteners attach the plate to bone. Each retainer may be a supplemental plate.

The selected retainer may be placed onto the plate, optionally after the plate has been disposed on the bone and attached to the bone with one or more fasteners and/or tools. The retainer may be mated with the plate at a pre-selected target position along the plate, or the retainer may be mated at a longitudinally offset position of the plate and then moved longitudinally along the plate to the target position, among others.

One or more fasteners for the retainer may be selected. The fasteners may be selected from a set of fasteners including at least linear fastener and at least one spanning member.

Each fastener selected for the retainer may be operatively disposed to couple the retainer to the bone. At least one linear fastener (e.g., a screw, pin, peg, rivet, etc.) may be placed into the bone from an aperture of the retainer. The linear fastener may engage the retainer, and may or may not lock to the aperture, such as via threaded engagement. In exemplary embodiments, the linear fastener avoids (i.e., does not extend through) the plate. In some embodiments, the retainer may have a pair of mounting regions (see Section I), and at least one threaded fastener may be operatively disposed in an aperture of each mounting region. In some embodiments, at least two threaded fasteners may be operatively disposed in at least one or both of the mounting regions. A spanning member also or alternatively may be connected operatively to the retainer, such that the retainer and spanning member collectively encircle the bone.

The spanning member may be installed by any suitable procedure. In some embodiments, a spanning member selected for installation may include (i) a line having a first stop member pre-mounted to a first end region of the line and (ii) a second stop member that is separate from, and not yet assembled with, the line. The line may be fed through a first aperture of a first mounting region of the retainer, starting at a second end region of the line opposite the first end region, until the first stop member contacts the retainer at the first aperture to restrict advancement of the line through the first aperture. The second end region may be fed around the bone and through a second aperture of a second mounting region of the retainer. The second stop member may be placed onto the second end region of the line and into the second aperture, the line tensioned, and the second stop member crimped to lock the second stop member to the line. When the stop member is crimped, both stop members may be seated in their respective apertures and collectively may prevent release of tension on the line. The line may be cut to remove a length of the line that is protruding from the top of the second stop member.

Claim 1:
A system for fixing bone (<NUM>), comprising:
an elongated plate (<NUM>) configured to be disposed longitudinally on a bone (<NUM>);
a retainer (<NUM>) having a body (<NUM>) interconnecting a pair of mounting regions (78a, 78b), the body defining a recess (<NUM>), each mounting region defining a first aperture (<NUM>) and a second aperture (<NUM>), the retainer being configured to be mated with the plate to position a section of the plate in the recess such that the retainer straddles the plate;
a line (<NUM>) configured to extend between the first apertures, such that the retainer and the line collectively encircle the plate and the bone, the line including wire and/or cable; and
a pair of stop members (96a, 96b) configured to be received on each end region of the line, thereby preventing the end region from passing through the first apertures of the mounting regions; wherein the first aperture of each mounting region defines a through-axis (<NUM>) oriented tangential to the bone to guide the line (<NUM>) in a circumferential direction on the bone, and wherein the second aperture of each mounting region defines a through-axis (<NUM>) passing through opposite sides of the bone while avoiding a medullary canal (<NUM>) thereof.