Guide sleeve and associated system for fine axial adjustment of fixation members - Patents.com

Abstract

A guide sleeve for use in securing a fixation member to an intramedullary nail and bone includes a sleeve body having an inner surface elongated along a central axis and defining a bore extending along the central axis to a distal end of the sleeve body. The sleeve body also defines a plurality of guide channels, each recessed radially outward from the inner surface and each including a helical proximal portion and a straight distal portion extending from the helical proximal portion toward the distal end. The straight distal portions are parallel to the central axis. The guide channels are configured to receive respective complementary followers of an instrument for driving the fixation member through the bore and subsequently through the intramedullary nail and into the bone.

Description

[Technical field]

[0001] The present invention relates to devices for providing precise control of the axial advancement of a fixation member within a bone, as well as systems and methods relating to intramedullary nailing techniques. [Background technology]

[0002] Fractures are often treated with screws or other fixation devices that are inserted into or through the bone to stabilize the fractured portions of the bone after the fractured portions are properly aligned. Trochanteric bone fixation procedures involve the insertion of an intramedullary nail into the medullary cavity of the bone, followed by the insertion of a bone fixation nail into the condylar portion of the bone at an angle to the intramedullary nail (i.e., along the axis of the femoral neck and the center of the femoral head). Summary of the Invention [Means for solving the problem]

[0003] According to one embodiment of the present disclosure, a bone fixation system for use with an intramedullary nail includes a guide sleeve having a sleeve body elongated along a central axis and configured to be held in place relative to a bone by an aiming arm. The sleeve body includes an inner surface defining a bore extending along the central axis to a distal end of the sleeve body. The sleeve body defines at least one guide channel recessed radially outward from the inner surface and includes a helical proximal portion and a straight distal portion, the straight distal portion extending from the helical proximal portion toward the distal end and parallel to the central axis. The system includes a fixation member configured to extend through the bore of the guide sleeve. The fixation member has a proximal mount and a distal head spaced distally from the proximal mount. The distal head has a helical structure configured to engage bone. The system includes an instrument and has an elongated portion including a distal mount configured to mate with a proximal mount of the fixation member such that when coupled, the instrument is configured to advance the fixation member through the bore of the guide sleeve, the elongated portion having an outer surface and at least one protrusion extending radially outward from the outer surface, the at least one protrusion configured to extend into and follow the at least one guide channel as the elongated portion advances through the bore of the guide sleeve to control an axial position of the fixation member relative to the guide sleeve.

[0004] According to another embodiment of the present disclosure, a guide sleeve for use in securing a fixation member to an intramedullary nail and bone includes a sleeve body having an inner surface elongated along a central axis and defining a bore extending along the central axis to a distal end of the sleeve body. The sleeve body also defines a plurality of guide channels, each recessed radially outwardly from the inner surface and each including a helical proximal portion and a straight distal portion extending from the helical proximal portion toward the distal end. The straight distal portions are parallel to the central axis. The guide channels are configured to receive respective complementary followers of an instrument for driving the fixation member through the bore and subsequently through the intramedullary nail and into the bone.

[0005] According to an additional embodiment of the present disclosure, a method of fixing an intramedullary nail in an intramedullary canal of a bone includes advancing a guide sleeve through a complementary opening of an aiming arm attached to the intramedullary nail, such that the guide sleeve's central axis intersects with a transverse channel of the intramedullary nail along a trajectory defined along a central axis, until a distal end of the guide sleeve contacts the outer cortex of the bone. The method includes inserting an instrument through the central bore of the guide sleeve such that an external follower of the instrument extends into a respective channel defined within an inner surface of the guide sleeve within the central bore, a proximal portion of the channel extending helically along the inner surface. The method includes simultaneously 1) advancing a fixation member coupled to a distal end of the instrument axially along the central axis, and 2) rotating the fixation member about the central axis, by impacting a proximal face of the instrument to move the external follower along a proximal portion of the channel, the impacting step advancing a helical construct of the fixation member through the transverse channel of the intramedullary nail and subsequently engaging the bone. The method includes the step of moving the outer follower into a distal straight portion of the channel extending parallel to the central axis by further impacting the proximal face, thereby axially advancing the fixation member into further engagement with the bone without substantially rotating the fixation member about the central axis. [Brief description of the drawings]

[0006] The foregoing summary, as well as the following detailed description of exemplary embodiments of the present application, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the structure of the present application, exemplary embodiments are shown in the drawings. It should be understood, however, that the present application is not limited to the precise arrangements and instrumentalities shown. [Figure 1] FIG. 1 is a perspective view of a bone fixing system including an intramedullary nail according to one embodiment of the present disclosure; [Diagram 2] 2 is an exploded perspective view of a locking assembly of the bone fixing system shown in FIG. 1; [Diagram 3] 3 is a perspective view of a fixing member of the locking assembly shown in FIG. 2. [Figure 4]FIG. 4 is a perspective view of the fixing member shown in FIG. [Diagram 5] FIG. 5 is a side cross-sectional view of the fixing member shown in FIGS. 3 and 4. [Figure 6] FIG. 3 is a perspective view of a distal mount of the insertion tool shown in FIG. [Figure 7] FIG. 7 is a side view of the distal mount shown in FIG. [Figure 8] FIG. 8 is a side view of the fixation member shown in FIGS. 2-5 attached to the distal mount shown in FIGS. 6 and 7. [Figure 9A] FIG. 9 is a bottom view of the fixing member shown in FIG. 8. [Figure 9B] 9B is a perspective view of the fixation member shown in FIG. 9A engaged with the locking member of the intramedullary nail shown in FIG. 1. [Figure 10] 3 is a side cross-sectional view of the guide sleeve shown in FIG. 2. [Figure 11] FIG. 11 is a rear perspective view of the guide sleeve shown in FIG. [Figure 12] FIG. 12 is a cross-sectional end view of the guide sleeve shown in FIGS. 10 and 11. [Figure 13] 6 is a side cross-sectional view of the fixing member of FIGS. 2 to 5 disposed within a guide sleeve in a first position. [Figure 14] 11 is a side cross-sectional view of a fixing member extending from a guide sleeve in a second position. FIG. [Figure 15] 11 is a side cross-sectional view of a fixing member extending from a guide sleeve in a third position. FIG. [Figure 16] 13 is a side cross-sectional view of a portion of an insertion instrument according to an additional embodiment of the present disclosure engaged with a guide sleeve, the insertion instrument having a boss that provides a visual indication of the axial position of the fixation member relative to the guide sleeve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The present disclosure may be more readily understood by reference to the following detailed description in conjunction with the accompanying drawings and examples, which form a part of this disclosure. It is to be understood that the present disclosure is not limited to the specific apparatus, methods, applications, conditions or parameters described and / or illustrated herein, and the terminology used herein is for the purpose of describing specific embodiments by way of example only, and is not intended to limit the scope of the present disclosure. Also, as used herein, including the appended claims, the singular forms "a," "an," and "the" include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise.

[0008] The term "plurality," as used herein, means more than one. When a range of values ​​is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of "about," it will be understood that the particular value forms another embodiment. All ranges are inclusive and combinable.

[0009] When used herein with respect to dimensions, angles, and other shapes, the terms "about" and "substantially" take into account manufacturing tolerances. Additionally, the terms "about" and "substantially" can include 10% greater or less than the stated dimension or angle. Additionally, the terms "about" and "substantially" can be equally applied to the particular values ​​stated.

[0010] 1, an exemplary embodiment of a bone fixation system 100 includes an intramedullary nail 102 for insertion into an intramedullary canal of a bone 104. In the illustrated embodiment, the bone 104 is a femur, although it should be understood that the bone fixation system 100 may be adapted for use with other bones as desired. A proximal end 106 of the intramedullary nail 102 may be coupled to an insertion handle 108 configured to insert the intramedullary nail 102 into the intramedullary canal via a nail insertion target in the cortex of the bone 104. For example, the intramedullary nail 102 may be a trochanteric nail for insertion into the intramedullary canal via an intracortical target location, such as at or slightly lateral to the tip of the greater trochanter. The insertion handle 108 can also be configured to mate with an aiming arm 110 that defines at least one aiming opening 112 (or alternatively, a channel) that extends along an aiming trajectory or axis 114 that intersects with a transverse channel or "locking hole" 116 of the intramedullary nail 102 in a generally lateral-to-medial direction. One or both of the insertion handle 108 and the aiming arm 110 can include adjustment features that allow adjustment of the position of the aiming arm 110 relative to the insertion handle 108, and thus also adjust the trajectory 114 of the aiming opening 112. For example, the trajectory 114 can be adjusted to coincide with the axis of the trochanter.

[0011] The bone fixation system 100 includes a locking assembly 200 configured to extend through the aiming opening 112 of the aiming arm 110 for inserting a fixation member 2 through the locking hole 116 of the intramedullary nail 102 to engage bone, such as the distal cortex of the bone. In the illustrated embodiment, the aiming arm 110 is configured to guide the insertion of the fixation member 2 through the femoral neck 105 and into the femoral head 107 along a trajectory 114 that intersects with the apex 109 of the femoral head 107. The locking assembly 200 includes a guide sleeve 4 insertable through the aiming opening 112 along the trajectory 114 through which additional instruments, such as guide wires, wire guides, drill bits, drivers, inserters, etc., can be guided and advanced into the bone 104 and / or intramedullary nail 102, including guiding and advancing additional instruments, such as guide wires, wire guides, drill bits, drivers, inserters, etc., into and / or through the locking hole 116 of the intramedullary nail 102. It should be appreciated that the outer surface 6 of the guide sleeve 4 preferably has a geometry complementary to the geometry of the inner surface of the aiming arm 110 within the aiming opening 112 so that the guide sleeve 4 is held snugly therein.

[0012] 2, a locking assembly 200 can include a fixation member 2, a guide sleeve 4, an insertion instrument 8 for advancing the fixation member 2 through the guide sleeve 4, and a coupling instrument 10 for coupling the fixation member 2 to the insertion instrument 8. The guide sleeve 4 is elongated along a central axis 12 and has a proximal end 14 and a distal end 16 spaced apart from one another along a longitudinal direction X oriented along the central axis 12. The guide sleeve 4 defines an axial bore 18 extending along the central axis 12 from the proximal end 14 to the distal end 16 along a distal direction XD oriented along the longitudinal direction X. The axial bore 18 can be centrally located within the guide sleeve 4 and thus can be referred to as a "central" bore 18. The guide sleeve 4 includes a proximal stop member, such as a flange 15, at its proximal end 14 that defines a proximal face 17 of the guide sleeve 4.

[0013] The fixation member 2 has a proximal end 20 and a distal end 22 spaced apart from one another along a longitudinal direction X. The fixation member 2 includes a proximal mount 24 for attachment to the insertion tool 8 and a head 26 spaced apart from the proximal mount 24 in a distal direction XD. The head 26 includes a bone-engaging feature, such as a helical structure 28, for engaging bone as the fixation member 2 advances distally from the guide sleeve 4. The helical structure 28 may include a plurality of helical cutting blades 30 that extend helically about the central axis 12 and are configured to cut, bite, or otherwise drill through bone material, including cortical and cancellous bone material. The fixation member 2 includes a locking member 32 configured for locking engagement with a complementary locking member of the intramedullary nail 102. In the illustrated embodiment, the locking member 32 defines one or more outer locking surfaces 34 that define a geometry configured to engage a complementary geometry of a complementary locking member of the intramedullary nail 102, as described in more detail below. The fixation member 2 preferably defines a cannulated portion 36 for receiving a guidewire or other instrument and / or for allowing delivery therethrough of materials such as cement, bone filler material, bone growth guide material, augmentation materials, such as bone grafts, and the like.

[0014] The insertion tool 8 has a proximal end 40 and a distal end 42 spaced apart from one another along a longitudinal direction X. The insertion tool 8 has a handle 44 at the proximal end 40 and an elongated insertion portion 46 extending from the handle 44 in a distal direction XD to the distal end 42. The handle 44 is shaped to provide ample grip for an operator's hand. The insertion portion 46 is configured to extend through the axial bore 18 of the guide sleeve 4 and includes a distal mount 48 at the distal end 42 for attachment to the proximal mount 24 of the fixation member 2. The distal mount 48 and the proximal mount 42 have complementary geometries for transmitting axial and rotational forces from the insertion tool 8 to the fixation member 2, as described in more detail below. The insertion portion 46 has an outer surface 50 defining at least one follower member, such as at least one protrusion 52, configured to engage and follow a complementary guide feature located within the axial bore 18 of the guide sleeve 4, thereby guiding the movement of the insertion portion 46 (and the fixation member 2 attached thereto) through the guide sleeve 4. Preferably, the at least one protrusion 52 includes a plurality of protrusions spaced non-uniformly from one another around the circumference of the outer surface 50 of the insertion portion 46. The engagement between the protrusions 52 and the complementary guide features within the axial bore 18 of the guide sleeve 4 is described in more detail below. The insertion instrument 8 includes a stop member, such as a flange 54, defining a distal stop surface 56 configured to abut the proximal surface 17 of the guide sleeve 4 when the insertion portion 46 (and thus the fixation member 2 attached thereto) is at a maximum insertion depth relative to the guide sleeve 4. The insertion instrument 8 also has a proximal stop surface 58 located at its proximal end 40 and defines a cannulation portion 59 extending from the proximal end 40 to the distal end 42 .

[0015] The coupling device 10 has a proximal end 60 and a distal end 62 spaced apart from one another along a longitudinal direction X. The coupling device 10 includes a proximal flange 64 at the proximal end 60 and an elongated portion 66 extending from the proximal flange 64 in a distal direction XD to the distal end 62. The elongated portion 66 of the coupling device 10 is configured to extend through the cannulated portion 12 of the insertion device 8 such that a coupling feature, such as an externally threaded coupling portion 67 at the distal end 62 extends distally from the distal mount 48 of the insertion device 8 and engages a complementary coupling feature, such as an internally threaded proximal portion of the fixation member 2, for coupling with the fixation member 2. The proximal flange 64 may have knurling or the like to facilitate rotation of the elongated portion 66 relative to the fixation member 2 to threadably engage the externally threaded coupling portion 67 of the coupling device 10 with the internally threaded proximal portion of the fixation member 2, thereby effectively drawing the fixation member 2 proximally relative to the distal mount 48 of the insertion device 8 such that the proximal mount 24 of the fixation member 2 is fully seated in the distal mount 48, in which position the proximal and distal mounts 24 and 48 preferably firmly engage one another. The coupling device 10, insertion device 8, and fixation member 2 may be cooperatively configured such that the distal surface 65 of the flange 64 abuts the proximal stop surface 58 of the insertion device 8 when the proximal mount 24 is fully seated in the distal mount 48. The coupling device 10 preferably defines a cannulation portion 68, such as for receiving a guidewire or other device.

[0016] 3-5, the proximal mount 24 of the fixation member 2 can include a plurality of attachment formations. One such attachment formation can include one or more lateral surfaces 70 (also referred to herein as "landings" or "flats") extending parallel to a lateral direction T perpendicular to the central axis 12. Another such attachment formation can include an additional flat, such as a lower flat 71 as shown in FIG. 5, located opposite the one or more lateral surfaces 70. Yet another such attachment formation can include an axial abutment surface 72 generally facing in a proximal direction XP opposite the distal direction XD. An additional such attachment formation can include a proximal surface 74 at the proximal end 20 of the fixation member 2. As shown, the proximal surface 74 can be inclined at an oblique angle relative to the central axis 12. Each of the attachment formations 70, 71, 72, 74 of the proximal mount 24 can be configured to engage a complementary attachment formation of the distal mount 48.

[0017] The fixation member 2 may optionally comprise two or more anchor bodies coupled together. For example, the fixation member 2 may include a distal anchor body 2a defining a head 26 and a proximal anchor body 2b defining a locking member 32 and a proximal end 20 of the fixation member 2. The proximal anchor body 2b may be tubular and may define a generally cylindrical outer surface 33. The proximal anchor body 2b may also be configured to receive a shank 76 of the distal anchor body 2a. The distal anchor body 2a and the proximal anchor body 2b may be configured for selective telescopic movement relative to one another. For example, the shank 76 of the distal anchor body 2a may include a matching pawl 78 configured to engage at least one of a series of complementary ratchet teeth 79 defined on or carried by an inner surface of the proximal anchor body 2b. Thus, the pawl 78 and ratchet teeth 79 can be used to selectively adjust the axial length L1 of the fixation member 2 prior to engaging the proximal mount 24 with the distal mount 48. It should be appreciated that the fixation member 2 can be configured as described in U.S. Patent No. 8,808,293, entitled "TROCHANTERIC FEMORAL NAIL AUGMENTABLE," issued August 19, 2014 (the "'293 reference"), the entire disclosure of which is incorporated herein by reference. As shown, the distal anchor body 2a can define a lateral flat 70 and an axial abutment surface 72, and the proximal anchor body 2b can define a proximal surface 74 of the fixation member 2.

[0018] The helical cutting blade 30 of the head 26 may extend helically about the central axis 18 at a helix angle A1 measured relative to the central axis 12 and may define a pitch along the longitudinal direction X. The head 26 may also define one or more side ports 38 in fluid communication with the cannulation 36. The one or more side ports 38 may be configured to deliver a material, such as any of the augmentation materials described above, from the head 26 in one or more respective radial directions R perpendicular to the central axis 12.

[0019] 6-8 , the distal mount 48 of the insertion instrument 8 can include a plurality of mounting formations complementary to those of the proximal mount 24 of the fixation member 2. For example, the distal mount 48 can include one or more lateral surfaces or flats 80 (also referred to herein as “landings”) extending parallel to the lateral direction T and configured to abut against the lateral flats 70 of the fixation member 2. The distal mount can also include a lower flat 81 extending parallel to the lateral direction T and configured to abut against the lower flat 71 of the fixation member 2. The distal mount 48 can also include a distal axial abutment surface 82 oriented generally in the distal direction XD and configured to engage the proximal axial abutment surface 72 of the fixation member 2. The distal axial abutment surface 82 can define the distal end 42 of the insertion instrument 8. The distal mount 48 can further include a distal shoulder surface 84 configured to face the proximal surface 74 of the fixation member 2. The distal shoulder surface 84 is preferably inclined at an oblique angle equivalent to the angle of the proximal surface 74. As shown in Figures 6 and 7, the externally threaded coupling portion 67 at the distal end 62 of the coupling instrument 10 extends distally from the distal mount 48 to engage the complementary internally threaded proximal portion of the fixation member 2, drawing the mounting formations 70, 71, 72 of the fixation member 2 into full seating engagement with the mounting formations 80, 81, 82 of the insertion instrument 8, as shown in Figure 8. The engaged transverse flats 70, 80 and 71, 81 transmit rotational forces to the fixation member 2, and the engaged axial abutment surfaces 72, 82 transmit axial forces to the fixation member 2, collectively providing a rigid and sturdy coupling that is critical to proper alignment and locking engagement between the one or more external locking surfaces 34 of the fixation member 2 and the complementary locking members of the intramedullary nail 102. A rigid and sturdy connection is also favourable for fine adjustability of the axial position of the fixation member 2 relative to the guide sleeve 4 (and therefore relative to the nail 102 and bone 104).

[0020] As shown in FIG. 9A, the fixation member 2 can define a pair of outer locking surfaces 34 that are opposite each other along the transverse direction T. The outer locking surfaces 34 may be recessed from the generally cylindrical outer surface 33 such that the proximal anchor body 2b defines retention shoulders 35 at the proximal and distal ends of the outer locking surfaces 34. As shown in FIG. 9B, the locking member of the intramedullary nail 102 may be a locking prong 120 having arms and configured to advance within the central passage of the intramedullary nail 102 such that the arms engage, specifically snugly, one of the outer locking surfaces 34 of the fixation member 2 if the fixation member 2 moves along the central axis 12 after locking with the intramedullary nail 102, such that the arms abut against the respective retention shoulders 35 of the fixation member 2. The retention shoulders 35 are configured to engage the locking member of the intramedullary nail 102 to prevent movement of the fixation member 2 along the medial-lateral direction. In other embodiments, the locking prong 120 can have a pair of opposing arms 122 configured to straddle the outer locking surface 34 of the fixation member 2 .

[0021] 10-12, the guide sleeve 4 comprises a sleeve body 5 defining a proximal end 14 and a distal end 16, an outer surface 6, and an axial bore 18. The sleeve body 5 may also define a flange 15. The sleeve body 5 is preferably a monolithic body. The sleeve body 5 defines an inner surface 90 that defines the axial bore 18. The sleeve body 5 also defines at least one guide channel 92 recessed radially outward from the inner surface 90 and extending between the proximal end 14 and the distal end 16 of the sleeve body 5. The at least one guide channel 92 is configured to guide movement of the fixation member 2 as it advances through the sleeve body 5. The at least one guide channel 92 includes a helical proximal portion 92a and a straight distal portion 92b extending from the helical proximal portion 92 toward the distal end 16 of the sleeve body 5. The helical proximal portion 92a is configured to rotate the fixation member 2 about the central axis 12 as the fixation member 2 advances through the bone material distal to the guide sleeve 4, thereby providing a preferred engagement between the helical blades 30 of the head 26 and the bone material moving therethrough. The straight distal portion 92b of the guide channel 92 is configured to provide precise fine adjustment of the axial position of the fixation member 2 relative to the bone material, such as, by way of non-limiting example, the spacing between the distal end 16 of the fixation member 2 and the apex 109 of the femoral head 107. Fine adjustment of the axial position of the fixation member 2 is described in more detail below.

[0022] As illustrated, the at least one guide channel 92 can include a plurality of guide channels spaced apart from one another around the circumference of the inner surface 90. In the illustrated embodiment, the plurality of guide channels 92 includes three (3) guide channels 92. The guide channels 92 are configured to receive corresponding follower members of the insertion instrument 8, such as protrusions 52 extending radially outward from the outer surface 50. The guide channels 92 are configured to guide the movement of the protrusions 52, and thus the elongated insertion portion 46, as it advances through the axial bore 18 of the guide sleeve 4. Preferably, the guide channels 92 are non-uniformly spaced apart from one another around the circumference of the inner surface 90 in a manner that corresponds to the non-uniform spacing of the protrusions 52 around the circumference of the outer surface 50 of the insertion portion 46 of the insertion instrument 8. In this manner, the protrusions 52 of the insertion instrument 8 only fit within their associated guide channels 92, ensuring that the fixation member 2 is in a desired orientation about the central axis 12 when the protrusions 52 are present in the straight distal portion 92b of the guide channels 92. It should be appreciated that in other embodiments, the sleeve body 5 can define one (1), two (2), four (4), five (5), six (6), or more than six guide channels 92, each of which can be configured to receive a corresponding follower member of the insertion instrument 8.

[0023] The helical proximal portion 92a of each guide channel 92 defines a helix angle A2 with respect to the central axis 12, which is preferably equal to the helix angle A1 of the helical cutting blade 30. Thus, as the insertion instrument 8 advances through the guide sleeve 4, the engagement between the projections 52 and the helical proximal portion 92a of the guide channels 92 substantially engages the helical blade 30 of the head 26 with the bone material primarily by a preferred compression mechanism, as opposed to a shearing mechanism, which provides the helical blade 30 with a self-channeling capability and provides improved fixation. The helix angles A1, A2 may be in the range of about 5 degrees to about 60 degrees, more specifically in the range of about 10 degrees to about 30 degrees, and more specifically in the range of about 15 degrees to about 20 degrees. The helix angle A2 of the helical proximal portion 92a of the guide channel 92 is preferably constant along the axial length of the helical proximal portion 92, although in other embodiments the helix angle may vary, such as to provide measured bone compression along the insertion trajectory. The straight distal portion 92b of each guide channel 92 extends parallel to the central axis 12 of the guide sleeve 4. The straight distal portion 92b of the guide channel 92 defines an axial length L2, which is preferably equal to or greater than 4.0 mm, may be equal to or greater than 5.0 mm, and may further range from about 4.0 mm to about 20 mm.

[0024] 13, the distal end 22 of the fixation member 2 is shown in a first insertion position P1 relative to the guide sleeve 4, where the follower 52 of the insertion instrument 8 is located near the proximal end of the helical proximal portion 92a of the guide channel 92. From the first insertion configuration P1, the surgeon can advance the insertion instrument 8 carrying the fixation member 2 distally through the central bore 18 by impacting the proximal face 58 of the insertion instrument 8 with an impact hammer or the like until the follower 52 is guided to the second insertion position P2.

[0025] 14 , when the fixation member 2 is in the second insertion position P2, the follower 52 is located at an interface 94 or transition between the helical proximal portion 92a and the straight distal portion 92b of the guide channel 92. It should be appreciated that in the second insertion position, the outer locking surface 34 of the fixation member 2 is properly oriented for engagement with the locking prongs of the intramedullary nail 102. Thus, if the axial position of the fixation member 2 relative to the intramedullary nail 102 is sufficient at the second insertion position P2, the surgeon may choose to forego further axial advancement of the fixation member 2 and instead move the locking member of the intramedullary nail 102 into locking engagement with the outer locking surface 34 of the fixation member 2.

[0026] 15, if further axial advancement of the fixation member 2 is desired or necessary, such as to ensure proper locking with the locking member of the intramedullary nail 102 and / or to achieve a better tip-to-apex distance, the surgeon can utilize the straight distal portion 92b of the guide channel 92 for incremental insertion, such as by applying several impacts, or even a single impact, to the proximal face 58 of the insertion instrument 89 while observing visual indicia of the axial position of the fixation member 2. Such visual indicia can include fluoroscopy. For example, the final portion of the fixation member 2 may be made of a radiopaque material or may carry one or more radiopaque markers for viewing under fluoroscopy. Additionally or alternatively, the visual indicia can include, as non-limiting examples, markings such as graduated hash marks on the outer surface 50 of the insertion portion 46 of the insertion instrument 8, or a raised boss 57 extending distally from the flange 56 at a predetermined length L3, as shown in FIG. 16, the raised boss 57 indicates when the insertion portion 46 of the insertion instrument 8 (and therefore the fixation member 2 attached thereto) is within a predetermined length L3 of the maximum insertion depth relative to the guide sleeve 4. The predetermined length L3 can correspond to the axial length L2 of the straight distal portion 92b of the guide channel 92, such that the raised boss 57 can indicate when the protrusion 52 is within the straight distal portion 92b. The aforementioned steps of incremental insertion can be repeated as necessary for fine adjustment of the insertion of the fixation member 2, optionally until the follower 52 is located at the distal end of the straight distal portion 92b of the guide channel 92, at which point the distal end 22 of the fixation member 2 is at the third maximum insertion position P3.

[0027] The axial length L2 of the straight distal portion 92b of the guide channel 92 is particularly advantageous because fixation members of intramedullary nailing systems are often provided in discrete increments of length L1, such as, for example, increments of 5.0 mm. Thus, if any combination of patient anatomy, intramedullary nail insertion location, and bone fragmentation, compression, or mobility requires a fixation member length L1 between such 5.0 mm increments, the physician may have to select between fixation member lengths L1 that may be up to 5.0 mm longer or shorter than the desired length L1. Such over- or under-length fixation members may present challenges in proper engagement with a complementary locking member of the intramedullary nail 102. For example, to ensure proper alignment between the outer locking surface 34 of the fixation member 2 and the arms 122 of the locking prongs 120, the axial position and rotational orientation of the fixation member 2 must be aligned with the arms 122 of the locking prongs 120; otherwise, the arms may not engage the outer locking surface 34, which may leave the fixation member 2 free to slide along the locking hole 106, which may result in movement of the fixation member 2 along a medial-to-lateral direction. Without the straight distal portion 92b of the guide channel 92, the surgeon must advance the fixation member 2 the full length of the helical guide channel to ensure proper engagement with the locking prongs, even if such full advancement results in less than the desired tip-to-apex distance. The straight distal portion 92b of the guide channel 92 maintains the orientation of the fixation member 2 for proper engagement with the locking prongs 120 while also allowing the surgeon to incrementally advance the fixation member to the optimal tip-to-apex distance.

[0028] Although the present disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations may be made herein without departing from the spirit and scope of the present invention as defined by the appended claims. For example, features of various embodiments described herein may be incorporated into one or more, and up to all, of the other embodiments described herein. Furthermore, the scope of the present disclosure is not limited to the specific embodiments described in the specification. As one skilled in the art would readily appreciate from the process, any currently existing or later developed machine, manufacturing method, composition of matter, means, method, or step that performs substantially the same function or achieves substantially the same result as the corresponding embodiment described herein may be utilized in accordance with the present disclosure.

[0029] [Embodiment] (1) A bone fixation system for use with an intramedullary nail, comprising: a guide sleeve including a sleeve body elongated along a central axis and configured to be held in place against a bone by an aiming arm, the sleeve body including an inner surface defining a bore extending along the central axis to a distal end of the sleeve body, the sleeve body defining at least one guide channel recessed radially outward from the inner surface and including a helical proximal portion and a straight distal portion, the straight distal portion extending from the helical proximal portion toward the distal end and parallel to the central axis; a fixation member configured to extend through the bore of the guide sleeve, the fixation member having a proximal mount and a distal head spaced distally from the proximal mount, the distal head having a helical structure configured to engage bone; an instrument having an elongated portion including a distal mount configured to mate with the proximal mount of the fixation member such that, when coupled, the instrument is configured to advance the fixation member through the bore of the guide sleeve, the elongated portion having an outer surface and at least one protrusion extending radially outward from the outer surface, the at least one protrusion configured to extend into and follow the at least one guide channel as the elongated portion is advanced through the bore of the guide sleeve to control an axial position of the fixation member relative to the guide sleeve; Equipped with Bone fixation system. (2) The bone fixing system of embodiment 1, wherein the straight distal portion of the at least one guide channel defines an axial length of at least 4.0 mm. (3) The bone fixing system of embodiment 1, wherein the guide sleeve, the instrument, and the fixation member are cooperatively configured such that the fixation member: 1) advances in the distal direction and rotates about the central axis as the at least one protrusion follows the spiral proximal portion of the at least one guide channel, and 2) advances in the distal direction without substantially rotating about the central axis as the at least one protrusion follows the straight distal portion of the at least one guide channel. (4) The bone fixation system of embodiment 3, wherein the instrument has a proximal end and an impact surface at the proximal end of the instrument, the impact surface configured to receive an impact from an impact member and thereby advance the at least one protrusion along at least a portion of the helical proximal portion and the straight distal portion of the at least one guide channel. (5) The bone fixation system of embodiment 1, wherein the at least one guide channel includes a plurality of guide channels defined by the inner surface of the guide sleeve, the plurality of guide channels being spaced substantially equidistant from one another around a circumference of the inner surface.

[0030] (6) The bone fixation system of embodiment 5, wherein the at least one protrusion includes a plurality of protrusions extending radially outward from the outer surface of the elongated portion of the instrument, the plurality of protrusions being non-uniformly spaced from one another around a circumference of the outer surface, the plurality of protrusions being configured to extend into and follow the plurality of guide channels, respectively. (7) The bone fixation system of claim 1, wherein the fixation member defines an outer locking surface configured to engage a complimentary locking member of the intramedullary nail, such that when the outer locking surface engages with the locking member, the fixation member is prevented from rotating relative to the intramedullary nail about the central axis. (8) The bone fixation system of claim 7, wherein the outer locking surface is a first outer locking surface, the fixation member defines a second outer locking surface opposite the first outer locking surface along a lateral direction perpendicular to the central axis, and the second outer locking surface is configured to abut a complementary locking surface of the intramedullary nail. (9) The first outer engaging surface and the second outer engaging surface are each flat and parallel to each other, the at least one guide channel and the fixation member are cooperatively configured such that the first and second outer locking surfaces each remain parallel to a central nail axis of the intramedullary nail while the at least one protrusion of the instrument resides within the straight distal portion of the at least one guide channel. 9. The bone fixing system of embodiment 8. (10) The bone fixing system of embodiment 1, wherein the helical structure of the distal head defines a helical angle substantially equivalent to a helical angle defined by the helical proximal portion of the at least one guide channel.

[0031] (11) The bone fixation system of claim 1, wherein the outer surface of the elongated portion of the instrument includes visual indicia to indicate the axial distance that the distal end of the distal head extends from the distal end of the guide sleeve. (12) At least the distal head of the fixation member is measured under X-ray fluoroscopy of an axial distance between a distal end of the distal head and a vertex of a portion of the bone. Visual Indication 2. The bone fixation system of claim 1, wherein the bone fixation system is made from a material that is radiopaque to provide (13) A guide sleeve for use in fixing a fixation member to an intramedullary nail and a bone, comprising: a sleeve body elongated along a central axis, the sleeve body having an inner surface defining a bore extending along the central axis to a distal end of the sleeve body, the sleeve body defining a plurality of guide channels each recessed radially outward from the inner surface, each of the plurality of guide channels including a helical proximal portion and a straight distal portion extending from the helical proximal portion toward the distal end and parallel to the central axis, the plurality of guide channels configured to receive respective complementary followers of an instrument for driving the fixation member through the bore and subsequently through the nail and into the bone; Equipped with Guide sleeve. (14) The guide sleeve of embodiment 13, wherein the straight distal portion of each of the guide channels defines an axial length of at least 4.0 mm. (15) The guide sleeve of claim 13, wherein the plurality of guide channels comprises three guide channels spaced apart from one another around the circumference of the inner surface.

[0032] (16) A method for fixing an intramedullary nail in an intramedullary canal of a bone, comprising the steps of: advancing the guide sleeve through a complementary opening in an aiming arm attached to the nail along a trajectory defined along a central axis of the guide sleeve such that the central axis intersects with a transverse channel of the nail until a distal end of the guide sleeve contacts the outer cortex of the bone; inserting an instrument through the central bore such that an outer follower of the instrument extends into a respective channel defined in an inner surface of the guide sleeve within the central bore, a proximal portion of the channel extending helically along the inner surface; impacting a proximal face of the instrument with a hammer to move the external follower along the proximal portion of the channel, thereby 1) advancing a fixation member coupled to a distal end of the instrument axially along the central axis, and 2) simultaneously rotating the fixation member about the central axis, the impacting step advancing a helical structure of the fixation member through the transverse channel of the nail and subsequently engaging bone; further impacting the proximal face with the hammer to move the outer follower into a distal linear portion of the channel extending parallel to the central axis, thereby axially advancing the fixation member into further engagement with the bone without substantially rotating the fixation member about the central axis; Including, method. (17) The method of claim 16, further comprising the step of observing a visual indicia representative of an axial spacing between the distal end of the fixation member and the bone during at least one of the impacting step and the further impacting step. (18) The method of claim 17, further comprising the step of terminating the further impacting step while the external follower is spaced proximally from a distal end of the distal straight portion of the channel during the observing step. 19. The method of claim 17, wherein the visual indicia include graduated hash marks on an exterior surface of the device or a raised boss extending from the exterior surface of the device. (20) The method of embodiment 17, wherein the visual indicia includes at least one radiopaque portion of the fixation member, and the observing step includes viewing the at least one radiopaque portion under fluoroscopy.

Claims

1. 1. A bone fixation system for use with an intramedullary nail, comprising: a guide sleeve including a sleeve body elongated along a central axis and configured to be held in place against a bone by an aiming arm, the sleeve body including an inner surface defining a bore extending along the central axis to a distal end of the sleeve body, the sleeve body defining at least one guide channel recessed radially outward from the inner surface and including a helical proximal portion and a straight distal portion, the straight distal portion extending from the helical proximal portion toward the distal end and parallel to the central axis; a fixation member configured to extend through the bore of the guide sleeve, the fixation member having a proximal mount and a distal head spaced distally from the proximal mount, the distal head having a helical structure configured to engage bone; an instrument having an elongated portion including a distal mount configured to mate with the proximal mount of the fixation member such that, when coupled, the instrument is configured to advance the fixation member through the bore of the guide sleeve, the elongated portion having an outer surface and at least one protrusion extending radially outward from the outer surface, the at least one protrusion configured to extend into and follow the at least one guide channel as the elongated portion is advanced through the bore of the guide sleeve to control an axial position of the fixation member relative to the guide sleeve; Equipped with Bone fixation system.

2. The bone fixing system of claim 1 , wherein the straight distal portion of the at least one guide channel defines an axial length of at least 4.0 mm.

3. 2. The bone fixing system of claim 1, wherein the guide sleeve, the instrument, and the fixation member are cooperatively configured such that the fixation member: 1) advances in the distal direction and rotates about the central axis as the at least one protrusion follows the helical proximal portion of the at least one guide channel, and 2) advances in the distal direction without rotating about the central axis as the at least one protrusion follows the straight distal portion of the at least one guide channel.

4. 4. The bone fixing system of claim 3, wherein the instrument has a proximal end and an impact surface at the proximal end of the instrument, the impact surface configured to receive an impact from an impact member thereby advancing the at least one protrusion along at least a portion of the helical proximal portion and the straight distal portion of the at least one guide channel.

5. 2. The bone fixation system of claim 1, wherein the at least one guide channel comprises a plurality of guide channels defined by the inner surface of the guide sleeve, the plurality of guide channels being spaced equidistant from one another around a circumference of the inner surface.

6. 6. The bone fixing system of claim 5, wherein the at least one protrusion comprises a plurality of protrusions extending radially outward from the outer surface of the elongated portion of the instrument, the plurality of protrusions being non-uniformly spaced from one another around a circumference of the outer surface, the plurality of protrusions being configured to extend into and follow the plurality of guide channels, respectively.

7. 2. The bone fixation system of claim 1, wherein the fixation member defines an outer locking surface configured to engage a complementary locking member of the intramedullary nail such that when the outer locking surface engages the locking member, the fixation member is prevented from rotating relative to the intramedullary nail about the central axis.

8. 8. The bone fixation system of claim 7, wherein the outer locking surface is a first outer locking surface and the fixation member defines a second outer locking surface opposite the first outer locking surface along a lateral direction perpendicular to the central axis, the second outer locking surface configured to abut a complementary locking surface of the intramedullary nail.

9. the first outer locking surface and the second outer locking surface are each planar and parallel to each other; the at least one guide channel and the fixation member are cooperatively configured such that the first and second outer locking surfaces each remain parallel to a central nail axis of the intramedullary nail while the at least one protrusion of the instrument resides within the straight distal portion of the at least one guide channel. The bone fixing system of claim 8.

10. The bone fixing system of claim 1 , wherein the helical structure of the distal head defines a helical angle identical to a helical angle defined by the helical proximal portion of the at least one guide channel.

11. The bone fixing system of claim 1 , wherein the outer surface of the elongated portion of the instrument includes visual indicia to indicate the axial distance that the distal end of the distal head extends from the distal end of the guide sleeve.

12. 2. The bone fixation system of claim 1, wherein at least the distal head of the fixation member is constructed from a material that is radiopaque to provide a visual indication under fluoroscopy of the axial distance between the distal end of the distal head and an apex of a portion of the bone.

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