Apparatus for bone fracture fixation

Technical Field

0001Embodiments of the present invention relate to the field of orthopedics, more specifically, to an apparatus for bone fracture fixation.

Background

0002Chest wall fractures, and in particular, fractures of rib bones of the rib cage, may cause potentially life-threatening respiratory insufficiencies, accounting for up to 50% of the mortality in thorax injuries. Fractures of a rib bone may occur at any location along the bone. However, the most critical fractures often involve multiple fractures of each of a set of adjacent rib bones. In particular, if four or more consecutive rib bones of the rib cage each sustain two or more fractures, for example, to create a column of bone fragments flanked by fracture sites, the fracture pattern is referred to as a flail chest injury. In flail chest injury, a fractured region of the chest wall is detached from the remainder of the chest wall, and no longer held in position by the rib cage. Accordingly, this fractured region may move independently of the chest wall during respiration, resulting, for example, in insufficient ability for respiration.

0003Flail chest injury may be treated non-operatively or operatively to restore the anatomy and physiological function of the chest wall. Non-operative treatment generally involves aggressive pain control and mechanical ventilation. As a result, non-operative treatment has been associated with prolonged stays in the hospital and increased mortality rates. Operative treatment generally involves reducing and stabilizing rib fractures with surgical fixation devices (osteosynthesis hardware), such as metallic struts, plates or wires. Operative stabilization of flail chest injuries, such as with struts, plates, or wires, may provide significant benefits over non-operative treatment. For example, operative stabilization may reduce the need for, and thus the mortality associated with, prolonged mechanical ventilation. In addition, operative stabilization may dramatically reduce pain during respiration, yield faster fracture healing, prevent persistent respiratory compromise, and reduce cost for treatment.

0004As early as 1958, intramedullary pinning with stainless steel pins was introduced to stabilize rib fractures by inserting a thin plate in the intramedullary canal across the fracture site, see <nplcit id="ncit0001" npl-type="s"><text>Moore, B.P., Operative stabilization of non-penetrating chest injuries, J. Thorac. Cardiovasc. Surg., 70, 619-639 (1975</text></nplcit>).

0005In other approaches, surgeons have inserted stainless steel (Kirschner) wires inside the ribs for rib fracture fixation. However, these thin, round wires provide little torsional stability, and may migrate over time.

0006In 1975, Paris et al. reported the use of stainless steel struts of three distinct sizes, which provided greater torsional stability, see <nplcit id="ncit0002" npl-type="s"><text>Paris, F., et al., Surgical stabilization of traumatic flail chest, Thorax, 30, 521-527 (1975</text></nplcit>).

0007These struts were used either as an intramedullary nail inside a rib or as an external brace for application on a rib surface. For external bracing, such struts utilized a series of holes to accommodate strut fixation with suture wires.

0008Other fixation mechanisms have been utilized, such as the Judet plate and the Vecsei plate, but are configured exclusively for external fixation of rib fractures. In 1972, Rehbein plates were introduced, which combine internal and external fixation strategies, see <nplcit id="ncit0003" npl-type="s"><text>Meier, P., et al., Zur Therapie des instabilen Thorax bei Rippenserienfrakturen, Schweiz. Med. Wschr., 108:606-613 (1978</text></nplcit>). A Rehbein plate is a thin, straight, flexible plate, which is angled at the end that remains outside the bone. For insertion of a Rehbein plate, an access hole may be drilled through the outer cortex of a rib several centimeters in front of the fracture. Through this access hole, the Rehbein plate may be inserted into the intramedullary canal across the fracture site, until only the angled end section of the Rehbein plate remains outside the rib. The angled end section may be folded toward the rib surface and secured, if necessary, with suture wire. However, folding of the angled segment to the rib segment may decrease the strength of the plate at the folding line. Folding of the stainless steel plate after insertion in the rib may also cause undesirable high stress in the rib, which may lead to further fracture or splitting of the rib especially in elderly patients in which ribs are thin and fragile. Furthermore, suturing the plate end to the bone is time consuming and difficult. This is especially the case, when rib fractures are located in the rear portion of the rib where thick soft tissue and muscle layers over ribs complicate or prevent access.

0009A system for stabilization of fractures of convex articular bone surfaces including subchondrial support structure is known from <patcit id="pcit0001" dnum="WO2005072284A"><text>WO 2005/072284</text></patcit>.

Brief Description of the Drawings

0010Embodiments of the present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figures 1, 2</figref>, <figref idref="f0002">3, 4</figref>, and <figref idref="f0003">5</figref> illustrate cross-sectional views of apparatuses affixed to bone in accordance with various embodiments of the present invention;</li><li><figref idref="f0003">Figure 6</figref> illustrates a perspective view of an apparatus for fixation of bone not according to the invention;</li><li><figref idref="f0004">Figure 7</figref> illustrates a perspective view of an apparatus for fixation of bone in accordance with various embodiments of the present invention; and</li><li><figref idref="f0004">Figures 8A</figref>, <figref idref="f0005">8B, and 8C</figref> illustrate a method of insertion of an apparatus for fixation of bone.</li></ul>

Detailed Description of Embodiments of the Invention

0011In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments in accordance with the present invention is defined by the appended claims and their equivalents.

0012Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent.

0013The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of embodiments of the present invention.

0014For the purposes of the present invention, the phrase "A/B" means A or B. For the purposes of the present invention, the phrase "A and/or B" means "(A), (B), or (A and B)". For the purposes of the present invention, the phrase "at least one of A, B, and C" means "(A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C)". For the purposes of the present invention, the phrase "(A)B" means "(B) or (AB)" that is, A is an optional element.

0015The description may use the phrases "in an embodiment," or "in embodiments," which may each refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," and the like, as used with respect to embodiments of the present invention, are synonymous.

0016Embodiments of the present invention provide an apparatus for fixing a rib with an osteosynthesis splint, which may be affixed to the outside surface of the rib on one side of the fracture, and which may extend into the intramedullary canal of the rib. In embodiments of the present invention, a splint may be introduced into a rib at the fracture site, or may enter the rib at an opening near a fracture site and extend along the intramedullary canal across the fracture site. Embodiments of the present invention may be used for fixing other bones, such as straight bones or other curved bones.

0017For the purposes of the present invention, the term osteosynthesis refers to a device or procedure that stabilizes and/or joins the ends of fractured bones, in part, using mechanical devices such as plates, pins, rods, splints, wires or screws.

0018For the purposes of the present invention, the terms "fixation" or "fixing" refers to the immobilization or stabilization of some or all of the parts of a fractured bone.

0019For the purposes of the present invention, the term "intramedullary" means occurring or residing within a bone, and may be used to describe, for example, devices that are completely or partially within a bone.

0020Embodiments of the present invention provide an apparatus for fixing ribs with an osteosynthesis splint. In accordance with an embodiment of the present invention, a splint may be affixed to the outside surface of a rib, for example on the anterior side of a fracture. In embodiments, an osteosynthesis splint may extend along the intramedullary canal of a rib and across the site of a fracture, or, alternatively, may be introduced at the site of a fracture.

0021In an embodiment of the present invention, no fixation means on the posterior side of the fracture is utilized, greatly reducing the need for surgical access to the posterior rib segments. This may not only reduce operating time, but may also reduce the amount of soft tissue dissection required for fixation of rib fractures in lateral and posterior rib segments, where thick layers of soft tissue and muscles complicate or prevent surgical access. In addition, in embodiments of the present invention, avoiding the use of additional posterior fracture fixation may allow an osteosynthesis splint of the present invention to move or flex slightly with the movement of the bone, thus avoiding unwanted additional stresses. In an embodiment of the present invention, the characteristic of the distal end of an osteosynthesis splint "floating" in the intramedullary canal of a bone avoids unwanted stresses associated with an additional posterior fixation and/or stresses conveyed back to the primary site of fixation due to tension or twisting of the splint.

0022<figref idref="f0001">Figure 1</figref> shows an exemplary apparatus 100 for fixing a fractured rib bone 102 with an osteosynthesis splint 104. Splint 104 may be inserted through a hole 106, created for example by drilling in the outer cortex of rib 102. In an embodiment of the present invention, for ease of insertion and access, hole 106 may be located anterior to fracture site 108. In other embodiments, hole 106 may be located posterior to fracture site 108.

0023In an embodiment of the present invention, to facilitate insertion of splints in a bone, a flexible reamer may be advanced through the drill hole or through a fracture site into the intramedullary canal of the bone to prepare a canal along which the osteosynthesis splint may be advanced.

0024In an embodiment, a splint may be advanced along the intramedullary canal in order to cross and stabilize the fracture site. As shown in <figref idref="f0001">Figure 1</figref>, splint 104 may be advanced until only the securing plate segment 110 of splint 104 remains visible outside rib 102. Securing plate 110 may be secured to rib 102 using one or more fasteners, for example bone screw 112, received in corresponding holes of securing plate 110 and into rib 102. In addition, in <figref idref="f0001">Figure 1</figref>, splint 104 extends across fracture site 108 providing stability to fracture site 108.

0025Embodiments of the present invention provide substantial advantages over fixation with either generic plates or intramedullary pins. For example, various embodiments of the present invention may not require access to the posterior rib segment for splint fixation, which may reduce both the operating time and the amount of soft tissue dissection during operation. Furthermore, embodiments of the present invention provide secure fixation of the osteosynthesis splint by screw fixation to prevent splint migration and fixation failure. Additional advantages of embodiments of the present invention are provided herein throughout the description.

0026<figref idref="f0001">Figure 2</figref> shows an exemplary apparatus 200 for fixing a fractured rib bone 202 with an osteosynthesis splint 204. Splint 204 may be inserted through a hole 206, created for example by drilling in the outer cortex of rib 202 near fracture site 208. Splint 204 may be advanced until only the securing plate segment 210 of splint 204 remains visible outside rib 202. Securing plate 210 may be secured to rib 202 using a plurality of fasteners, for example bone screws 212, received in corresponding holes of securing plate 210 and into rib 202.

0027.Bone screws 212 are shown extending through rib 202, but, in alternative embodiments of the present invention, screws may terminate in the intramedullary canal or may terminate in the bone cortex. In addition, in an embodiment of the present invention, screws may be utilized in various alignments, configurations, and/or insertion directions.

0028In embodiments of the present invention, fasteners other than screws may be utilized, such as pins, rods or wires. In an embodiment of the present invention, if a wire or similar fixation mechanism is utilized, a through hole in a securing plate may not be needed. Further, in embodiments of the present invention, combinations of various securing mechanisms may be utilized.

0029<figref idref="f0002">Figure 3</figref> shows an exemplary apparatus 300 for fixing a fractured bone 302 with an osteosynthesis splint 304. Splint 304 may be inserted through a hole 306, created for example by drilling in the outer cortex of bone 302 near fracture site 308. Splint 304 may be advanced until only the securing plate segment 310 of splint 304 remains visible outside bone 302. Securing plate 310 may be secured to bone 302 using a plurality of fasteners, for example bone screws 312, received in corresponding holes of securing plate 310 and into bone 302.

0030Bone 302 is representative of any of a variety of bones found in an animal body, whether straight or curved, and having a variety of cross-sections that may be fixed using an embodiment of the present invention.

0031<figref idref="f0002">Figure 4</figref> shows an exemplary apparatus 400 for fixing a fractured rib bone 402 with an osteosynthesis splint 404. Splint 404 may be inserted through a hole 406, created for example by drilling in the outer cortex of rib 402 near fracture site 408. Splint 404 may be advanced until only the securing plate segment 410 of splint 404 remains visible outside rib 402. Securing plate 410 may be secured to rib 402 using a plurality of fasteners, for example bone screws 412, received in corresponding holes of securing plate 410 and into rib 402. In addition, in <figref idref="f0002">Figure 4</figref>, splint 404 extends across and provides stability to fracture sites 408 and 409.

0032<figref idref="f0002">Figure 4</figref> shows a splint 404 being used to fix two fracture sites, but, in embodiments of the present invention, a splint may be used to fix one, two, three, or more fractures of a single bone.

0033<figref idref="f0003">Figure 5</figref> shows an exemplary apparatus 500 for fixing a fractured rib bone 502 with an osteosynthesis splint 504. Splint 504 may be inserted into rib 502 at fracture site 508 thus avoiding the need for creating or using an additional insertion location. Splint 504 may be advanced until only the securing plate segment 510 of splint 504 remains visible outside rib 502. Securing plate 510 may be secured to rib 502 using a plurality of fasteners, for example bone screws 512, received in corresponding holes of securing plate 510 and into rib 502.

0034<figref idref="f0003">Figure 6</figref> shows an osteosynthesis splint 600 for fixing bones not falling within the scope of the claims. Splint 600 includes a securing plate segment 602 having at least one opening 604 arranged in securing plate segment 602 openings 604 may be through-holes extending through osteosynthesis splint 600. Each opening 604 may be threaded or nonthreaded.

0035Securing plate segment 602 may include one or more notches 606 (shown in dashed outline) formed in securing plate segment 602. Notches 606 may be present in one or both opposing lateral edges of securing plate segment 602, and may have various shapes and sizes.

0036Notches 606 may be utilized as a location at which to support or provide plate fixation, for example, with suture wire. Notches 606 may provide a location at which to engage pliers or other gripping or insertion tool to aid in inserting splint 600 into a bone.

0037Splint 600 also includes transition segment 608, which provides for an offset between the plane of plate segment 602, and the plane of intramedullary segment 610. When in use, at transition segment 608, osteosynthesis splint 600 transitions from the outer surface of a bone to the intramedullary canal of the bone. Furthermore, before or at transition segment 608, the width of plate segment 602 narrows gradually to the width of intramedullary segment 610.

0038Transition segment 608 may have a variety of angles with respect to intramedullary segment 610, such as approximately 90°, 100°, 120°, 135° or 150°, depending on the desired application or the type or orientation of the bone to be fixed.

0039Splint 600 includes intramedullary segment 610, which penetrates the intramedullary canal of a bone across, and/or at, one or more fracture sites. Intramedullary segment 610 may have a circular cross-section, oval cross-section, elliptical cross-section, rectangular cross-section, or other polygonal cross-section suitable for insertion into the intramedullary canal of a bone, such as a rib bone. Distal end 612 of intramedullary segment 610 may be rounded, tapered, or pointed in order to help facilitate insertion of osteosynthesis splint 600 into a bone.

0040<figref idref="f0004">Figure 7</figref> shows an exemplary osteosynthesis splint 700 for fixing bones, in particular curved bones such as ribs. Splint 700 includes a securing plate segment 702 having at least one opening 704 arranged in securing plate segment 702. In embodiments of the present invention, openings 704 may be through-holes extending through osteosynthesis splint 700. In embodiments of the present invention, each opening 704 may be threaded or nonthreaded.

0041Splint 700 also includes transition segment 708, which connects plate segment 702 with intramedullary segment 710. When in use, in transition segment 708, osteosynthesis splint 700 transitions from the outer surface of a bone to the intramedullary canal of the bone.

0042Splint 700 includes intramedullary segment 710, which penetrates the intramedullary canal of a bone across, and/or at, one or more fracture sites. Intramedullary segment 710 may have a circular cross-section, oval cross-section, elliptical cross-section, rectangular cross-section, or other polygonal cross-section suitable for insertion into the intramedullary canal of a bone, such as a rib bone. Distal tip 712 of intramedullary segment 710 may be rounded, tapered, or pointed in order to help facilitate insertion of osteosynthesis splint 700 into a bone.

0043As shown in <figref idref="f0004">Figure 7</figref>, intramedullary segment 710 includes a distal segment 714 and a proximal segment 716. Proximal segment 716 has a larger width than the width of distal segment 714. In an embodiment of the present invention, the width of proximal segment 716 may taper gradually or may transition sharply to the width of distal segment 714. In embodiments of the present invention, distal segment 714 and proximal segment 716 may have the same or different thicknesses.

0044In an embodiment of the present invention, distal segment 714 and/or proximal segment 716 may have substantially uniform widths along all or a portion of each segment.

0045In an embodiment of the present invention, distal segment 714 and proximal segment 716 possess different degrees of flexibility. In the present invention, proximal segment 716 is wider than it is thick, for example, in a ratio of width to thickness of about 1.5:1, 2:1, 3:1, or more, and thus possesses a higher degree of vertical flexibility (720) than lateral flexibility (718). In an embodiment of the present invention, distal segment 714 may have a width and thickness with similar dimensions, or may be constructed with either dimension larger than the other to control the flexibility characteristics. In an embodiment of the present invention, distal segment 714 has a width and thickness in a ratio of about 1:1 and thus possesses substantially uniform flexibility characteristics in all directions.

0046In an embodiment of the present invention, the different widths of distal segment 714 and proximal segment 716 provide for easier insertion of the splint into a bone.

0047In embodiments of the present invention, osteosynthesis splints may have any suitable length. The length of a securing plate segment may be sufficient for splint fixation with a single screw, or multiple screws. Exemplary lengths of a plate segment may be about 5-50 mm, for example, about 10-20 mm. Alternatively, in an embodiment of the present invention, a securing plate segment may be sufficiently long to span and stabilize a second fracture site anterior to the fracture that is stabilized with an intramedullary segment. Thus, in other embodiments of the present invention, exemplary lengths of a plate segment may be about 30-200 mm, for example, about 50-100 mm. In embodiments of the present invention, exemplary lengths for a transition segment may be about 2-10 mm, for example, about 4-8 mm. In embodiments of the present invention, exemplary lengths for an intramedullary segment may be about 20-100 mm, for example about 40-80 mm.

0048Segments of an osteosynthesis splint according to embodiments of the present invention may have any suitable width. For example, a plate segment may have a width of about 5-15 mm, for example 8-10 mm, such as 9 mm, among others.

0049In an embodiment of the present invention, an intramedullary segment, for example, may have a width of about 1-10 mm, for example 2-8 mm, such as 5 mm, among others. The width of an intramedullary segment may be substantially constant along the length of the intramedullary segment, or may vary, for example, to facilitate easier insertion, or to alter the bendability or flexibility in particular regions, or from one region to the next. For example, in an embodiment of the present invention in an intramedullary segment containing a proximal segment and a distal segment, a proximal segment may have a width of about 2-8 mm, such as 5 mm, and a distal segment may have a width of about 0.5-3 mm, such as 2 mm.

0050An osteosynthesis splint in accordance with embodiments of the present invention may have any suitable thickness. In an embodiment of the present invention, the thickness may be substantially constant along the length of an osteosynthesis splint, or may vary, for example, to facilitate easier insertion, or to alter the bendability or flexibility at particular regions. Exemplary thicknesses for plate segments or intramedullary segments in accordance with embodiments of the present invention may be about 0.5 - 3 mm.

0051In an embodiment of the present invention, an osteosynthesis splint may have any suitable out-of-plane curvature, such as a longitudinal curvature, or may lack a curvature. In an embodiment of the present invention, a curvature of the entire osteosynthesis splint or segments thereof may be similar to, or matched to, the curvature of a portion of a bone, such as a rib. In an embodiment of the present invention, a splint, or a segment of a splint, may have a radius of curvature of about 5-30 cm.

0052In an embodiment of the present invention, a plate segment may have any suitable number, orientation or configuration of openings. In embodiments of the present invention, openings may include one or a plurality of holes extending between the inner and outer surfaces of the plate segment. The holes may be disposed along the centerline of the plate segment, or off-center, staggered, or side-by-side. Furthermore, in an embodiment of the present invention, the holes may be spaced equally or non-equally. In embodiments of the present invention, the holes may be spaced apart, for example, by about 5-15 mm, for example about 10 mm. Each hole may be threaded or nonthreaded, for threaded or nonthreaded engagement, respectively, with various bone screws, pins, etc.

0053In embodiments of the present invention, an osteosynthesis splint may have any suitable mechanical properties. For example, in an embodiment of the present invention, a securing plate segment and/or an intramedullary segment may be configured to substantially match the strength of the bone to be fixed, so that the segments have sufficient fixation strength while avoiding critical stress concentrations due to an exceedingly stiff implant.

0054In embodiments of the present invention, osteosynthesis splints, or portions thereof, may be made, for example, of a malleable material, such as medical grade titanium (Ti6Al4V) or stainless steel (316L). In an embodiment of the present invention, an osteosynthesis splint may be constructed of a material being sufficiently malleable to allow for perioperative adjustment to conform the splint to a particular bone geometry. In embodiments of the present invention, osteosynthesis splints may be unitary (constructed of one piece of material), or may be multi-part, connected or bonded in any suitable manner.

0055In embodiments of the present invention, osteosynthesis splints may be permanent or removable.

0056Osteosynthesis splints according to embodiments of the present invention may be used in methods of fixing bones, such as rib bones. <figref idref="f0004">Figures 8A</figref>, <figref idref="f0005">8B, and 8C</figref> illustrate an exemplary method.

0057An osteosynthesis splint 802 may be inserted into intramedullary canal 804 of bone 806, such as a rib bone, through insertion hole 808, which is present or has been formed, for example by drilling into the outer cortex of bone 806, in proximity to fracture site 810. hole 808 may be created approximately 10-40 mm, for example 20-30 mm, away from fracture site 810 hole 808 may be created with any suitable size to permit insertion of an osteosynthesis splint. For example, hole 808 may be about 1-4 mm, for example 2 mm, larger than the splint to be inserted. Hole 808 may be created in a variety of shapes including circular, oval, elliptical, rectangular, etc.

0058Alternatively, osteosynthesis splint 802 may be inserted at fracture site 810, directly into intramedullary canal 804, with an exemplary result of such an insertion shown, for example, in <figref idref="f0003">Figure 5</figref>.

0059As shown in <figref idref="f0005">Figure 8B</figref>, splint 802 may be partially inserted into intramedullary canal 804, and axially rotated (rotated about the longitudinal axis of splint 802) to align the curvature of splint 802 with the curvature of bone 806 (as shown by arrow 816). Splint 802 may be rotated approximately 180°.

0060Upon complete insertion of intramedullary segment 812 into intramedullary canal 804, plate segment 814 may be attached to the outer surface of bone 806. An osteosynthesis splint 802 may be inserted into intramedullary canal 804 through an insertion hole 808. To facilitate insertion of splint 802 through insertion hole 808, the width of distal segment 818 of intramedullary segment 812 may be less than the width of proximal segment 820 (see, for example, <figref idref="f0004">Figure 7</figref>). Osteosynthesis splint 802 may have a longitudinal curvature along all, or a portion of splint 802, as shown, for example, in distal segment 818 in <figref idref="f0004">Figure 8A</figref>. If a longitudinal curvature is present in splint 802, insertion may be initiated with the curvature of the splint opposing the curvature of bone 806. After distal segment 818 has been inserted, osteosynthesis splint 802 may be rotated to align its curvature with that of bone 806, such as the curvature of a rib bone. Subsequent to curvature alignment, intramedullary segment 812 of osteosynthesis splint 802 may be completely inserted along intramedullary canal 804 of bone 806 (see <figref idref="f0005">Figure 8C</figref>).

0061In an embodiment of the present invention, distal segment 818 may be sufficiently flexible to allow distal segment 818 to flex upon contact with a wall of intramedullary canal 804 to facilitate insertion of intramedullary segment 812. Distal segment 818 may be flexible regardless of whether all, or a portion of, intramedullary segment is curved. without utilizing a curved splint, a flexible splint, and/or a splint having a distal segment with a reduced width, a larger entry hole may be needed to ensure complete insertion of an osteosynthesis splint, whether being inserted into a straight or curved bone. Thus, the present invention provides various mechanisms that may be used alone or in combination to ensure simple and complete insertion of an osteosynthesis splint into a bone.

0062Although certain embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that embodiments in accordance with the present invention may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments in accordance with the present invention be limited only by the claims and the equivalents thereof.