Modular retaining screwdriver

Abstract

This invention provides a modular system for treating bone, comprising a body including a channel extending through the body. A distal end includes a drive feature sized and shaped to engage a corresponding drive structure of one of a first and a second bone screw. The system also includes an inner shaft sized and shaped to be inserted into the channel, and the inner shaft includes a distal end including a retaining feature for engaging a corresponding retaining structure extending within a groove at the proximal end of the first screw. Furthermore, the system includes an outer shaft extending longitudinally and including a channel extending through the outer shaft. The channel of the outer shaft is sized and shaped to slidably receive the body within the channel, and the channel includes a retaining feature extending along its distal end. The retaining feature of the outer shaft engages a retaining structure extending along the outer surface of the second screw.

Description

Background Technology

[0001] Bone screws can be used to fix bone fixation devices, such as, for example, intramedullary nails and / or bone plates. A driving device, such as a screwdriver, is used to insert the bone screw. In some cases, the bone screw may disengage from the screw during drive into the bone, which can lead to wear and / or difficulty in inserting the bone screw. Summary of the Invention

[0002] This disclosure relates to a modular system for treating bone. The system includes a body comprising an elongated member extending from a proximal end to a distal end and including a channel extending longitudinally through the elongated member. The proximal end is attached to a shank member, and the distal end includes a drive feature sized and shaped to engage a corresponding drive structure of a first bone screw and a second bone screw. An inner shaft includes a longitudinal element sized and shaped to insert into the channel through the elongated member of the body, extending from the proximal end to the distal end, the distal end including a drive structure for engaging a first bone screw. The body has a retaining feature extending within a groove at its proximal end, corresponding to an internal retaining structure; and an outer shaft extending longitudinally from the proximal end to the distal end and including a channel extending through the outer shaft, the channel being sized and shaped to slidably receive an elongated member of the body within the channel, and the channel including a retaining feature extending along its distal end, the retaining feature of the outer shaft being configured to engage an external retaining structure extending along the outer surface of the second bone screw, wherein the body can be selectively fitted with one of the inner shaft and the outer shaft to drive one of the first bone screw and the second bone screw into the bone.

[0003] In one embodiment, the retaining feature of the inner shaft includes a thread extending along its distal end.

[0004] In one embodiment, the inner shaft includes a knob attached to the proximal end of the longitudinal element, the knob extending proximal to the handle member of the body when the inner shaft is assembled with the body.

[0005] In one embodiment, the knob includes a plurality of grooves along its outermost radial surface to facilitate gripping of the knob.

[0006] In one embodiment, each of the plurality of grooves is asymmetrical about the central axis extending through the center of the knob and the midpoint between the first and second ends of each groove.

[0007] In one embodiment, each of the plurality of grooves is configured as a generally arcuate groove such that a first portion of the arcuate groove extending between a first end and a midpoint has a larger radius of curvature than a second portion of the arcuate groove extending between a second end and a midpoint.

[0008] In one embodiment, the retaining feature of the outer shaft includes a thread extending along the inner surface of the channel at the distal end of the outer shaft.

[0009] In one embodiment, the outer shaft includes a locking member that includes a tab biased into a channel of the outer shaft, and the elongated member includes a corresponding locking groove extending around a portion of the elongated member, such that when the elongated member is inserted into the channel of the outer shaft, the tab of the locking member is pushed out of the channel until the locking groove is positioned adjacent to the tab and the tab is allowed to return to its biased configuration to be received within the locking groove.

[0010] In one embodiment, the drive structure of the first and second bone screws is configured as a first groove extending into its proximal end, the size and shape of the first groove being set to correspond to the drive feature portion of the body.

[0011] In one embodiment, the first bone screw and the second bone screw further include a second groove extending distally from the first groove, and the retaining structure of the first bone screw and the second bone screw includes threads extending along the second groove.

[0012] In one embodiment, the second bone screw includes threads extending along its entire length.

[0013] This disclosure also relates to a method for treating bone. The method includes selecting one of a first bone screw and a second bone screw for implantation into bone, the first bone screw including a retaining structure extending along its inner surface defined by a groove extending distally to a proximal end of the first bone screw, the second bone screw including a retaining structure extending along an outer surface along a proximal portion of the second bone screw; and assembling one of an inner shaft and an outer shaft with a body of a modular screwdriver system to form a retaining screwdriver based on the selected first bone screw and the second bone screw, the body including an elongated member extending from a proximal end to a distal end and including a channel extending longitudinally through the elongated member, the distal end including a drive feature sized and shaped to correspond to the drive structure of one of the first bone screw and the second bone screw, the inner shaft including a retaining feature for engaging the retaining structure of the first bone screw, and the outer shaft including a retaining feature configured to engage the retaining structure of the second bone screw.

[0014] In one embodiment, one of the inner and outer shafts is assembled with the body to allow the assembled inner and outer shafts to rotate relative to the elongated member of the body.

[0015] In one embodiment, an inner shaft is assembled within the body, comprising a channel through which a longitudinal element of the inner shaft is inserted, such that the distal end of the longitudinal element, including a retaining feature of the inner shaft, extends distally through a driving feature of the body.

[0016] In one embodiment, assembling an outer shaft within the body includes inserting an elongated member into the body through a channel passing through the outer shaft.

[0017] In one embodiment, when the elongated member is inserted into the desired position within the outer shaft, the locking member of the outer shaft returns to a biased configuration to be received within a corresponding locking groove extending around the periphery of the elongated member.

[0018] In one embodiment, the method further includes engaging the assembled retaining screwdriver to one of the first and second bone screws.

[0019] In one embodiment, attaching the assembled retaining screwdriver to the first bone screw includes threading the retaining feature of the inner shaft with the retaining structure of the first bone screw and inserting the driving feature of the body into the driving structure of the first bone screw.

[0020] In one embodiment, the retaining structure that connects the retaining feature of the inner shaft to the first bone screw includes a knob in a first direction via a proximal end of a longitudinal member attached to the inner shaft that rotates the inner shaft relative to the first bone screw, the knob extending proximally toward a shank member attached to a proximal end of an elongated member of the body.

[0021] In one embodiment, the knob includes a plurality of grooves along its radially outermost surface to facilitate gripping of the knob, each of the plurality of grooves being configured as a generally arcuate groove such that a first portion of the arcuate groove extending between a first end and a midpoint has a larger radius of curvature than a second portion of the arcuate groove extending between a second end and a midpoint, the first portion of which the user grips when rotating the inner shaft in a first direction.

[0022] In one embodiment, the inner shaft is disengaged from the first bone screw by rotating the inner shaft relative to the body in a second direction opposite to the first direction, and the user grasps the second part of the knob when rotating the inner shaft in the second direction.

[0023] In one embodiment, attaching the assembled retaining screwdriver to the second bone screw includes threading the retaining structure of the second bone screw into the distal end of the outer shaft and inserting the drive feature of the body into the drive structure of the first bone screw such that when the body rotates relative to the outer shaft to drive the second bone screw into the bone, the retaining structure of the second bone screw disengages from the retaining feature of the outer shaft. Attached Figure Description

[0024] Figure 1 A longitudinal side view of a system according to an exemplary embodiment of the present disclosure is shown;

[0025] Figure 2 It shows Figure 1 A longitudinal sectional view of the first component of the system, wherein the main body is assembled with the inner shaft;

[0026] Figure 3 It shows that according to Figure 1 A partial sectional view of the first bone screw in the system;

[0027] Figure 4 As shown Figure 2 An enlarged longitudinal sectional view showing the main body and inner axis joined by bone screws.

[0028] Figure 5 It shows that according to Figure 1 A side view of the knob on the inner shaft of the system;

[0029] Figure 6 It shows Figure 1 A longitudinal sectional view of the second component of the system, wherein the main body is in accordance with... Figure 1 The outer shafts of the system are assembled together;

[0030] Figure 7 It shows that according to Figure 1 The longitudinal side view of the second bone screw of the system;

[0031] Figure 8 As shown Figure 6 An enlarged longitudinal sectional view showing the main body and outer shaft joined by bone screws.

[0032] Figure 9 A longitudinal sectional view of a system according to another exemplary embodiment of this disclosure is shown; and

[0033] Figure 10 A longitudinal sectional view of a system according to yet another exemplary embodiment of the present disclosure is shown;

[0034] Figure 11 A longitudinal side view of a system according to another embodiment of this disclosure is shown; and

[0035] Figure 12 A first longitudinal side view of a system according to another exemplary embodiment of this disclosure is shown; and

[0036] Figure 13 It shows that according to Figure 12 The system has a second longitudinal side whose main body is rotated 90 degrees relative to the first longitudinal side view. Detailed Implementation

[0037] This disclosure is understood with reference to the following description and accompanying drawings, wherein like reference numerals denote similar elements. This embodiment relates to bone treatment, and more particularly to a modular screwdriver system including features for engaging and driving various types of bone screws. Exemplary embodiments describe a modular retaining screwdriver system, which is combined with instruments for driving different types of retaining bone screws. The retaining bone screw includes a retaining feature configured to engage the screwdriver such that disengagement of the bone screw from the screwdriver is prevented during insertion of the bone screw into the bone, thereby providing easier and faster bone screw insertion.

[0038] An exemplary modular screwdriver system includes both an inner shaft and an outer shaft, which can be selectively assembled with a longitudinal body to drive bone screws, respectively, with the retaining feature extending inside the bone screw head or with the retaining feature extending outside the bone screw head. The combined instrument reduces costs and saves space on the surgical tray. Those skilled in the art will understand that although exemplary embodiments are shown and described with respect to locking bone screws for intramedullary nails, the screwdriver system of this disclosure can be used to engage and drive any of a variety of bone screws of any type in a variety of different types of bone fixation systems. For example, the screwdriver system of the present invention can also be used to place isolated single screws, screws for fixing bone plates, or combinations thereof.

[0039] like Figures 1 to 8 As shown, a modular retaining screwdriver system 100 according to an exemplary embodiment of this disclosure includes a body 102 to which an inner shaft 104 or an outer shaft 106 may be selectively fitted to engage and drive a bone screw, such as, for example, a bone screw. One possible bone screw is shown as a first bone screw 108, which includes a retaining structure 130 extending inward along its head portion 120. Alternatively, a second bone screw 110 may be engaged, which includes a retaining structure 132 extending outward along its head portion 124. The body 102 also includes an elongated member 112 and a shank portion 114 for engaging one of the inner shaft 104 and the outer shaft 106.

[0040] The distal end 116 of the elongated member 112 is configured, for example, to engage drive structures 126, 128 of corresponding size and shape with bone screws 108, 110, such that the elongated member 112 rotatably drives the first bone screw 108 and the second bone screw 110 into or out of the bone via rotation of the shank portion 114, depending on the direction of rotation. The distal end 118 of the inner shaft 104 is configured to engage a retaining structure 130 with the first screw 108, such that when the inner shaft 104 and the body 102 are assembled together, the inner shaft 104 can engage and retain the first screw 108 while driving the first screw 108 into or out of the bone. The distal end 122 of the outer shaft 106 is configured to engage a retaining structure 132 with the second bone screw 110, such that when the outer shaft 106 is assembled with the body 102, the outer shaft 106 can engage and retain the second screw 110 while driving the second screw 110 into or out of the bone.

[0041] The body 102 includes an elongated member 112 extending along a longitudinal axis from a proximal end 134 to a distal end 116. A handle portion 114 is attached to the proximal end 134 such that the handle portion 114 can be grasped by a user (e.g., a surgeon). The distal end 116 includes an actuation feature 136 configured to engage corresponding size and shape actuation structures of bone screws (such as actuation structures 126, 128 of, for example, the first bone screw 108 and the second bone screw 110), such that rotation of the handle portion 114 about the longitudinal axis of the elongated member 112 rotatably drives the first bone screw 108 and the second bone screw 110 into or out of the bone. In one embodiment, the actuation feature 136 includes a hexagonal or star-shaped structure configured to insert into grooves of corresponding size and shape of the actuation structures 126, 128. However, those skilled in the art will understand that as long as the drive feature 136 is configured to be non-rotatably received within the drive structures 126, 128 of the first bone screw 108 and the second bone screw 110, the drive feature 136 can have any of a variety of sizes and shapes, such that rotation of the body 102 rotatably drives the first bone screw 108 and the second bone screw 110.

[0042] The elongated member 112 includes a proximal portion 142 and a distal portion 144 connected to each other via a shoulder 140. A channel 138 extends from the proximal end 134 to the distal end 116 through both the proximal and distal portions 142, and is sized and shaped to receive the inner shaft 104 within the channel. The proximal portion 142 has both a larger inner and outer diameter than the distal portion 144, such that the shoulder 140 provides a transition between the inner and outer diameters. Therefore, the portion of the channel 138 extending through the distal portion 144 has a smaller diameter than the portion extending through the proximal portion 142. As will be described in further detail below, the inner surface of the shoulder 140 is configured to surround the portion of the inner shaft 104 inserted into the channel 138 to define the most distal position of the inner shaft 104 relative to the body 102.

[0043] In one embodiment, the proximal portion 142 includes a locking groove 156 extending around the proximal portion. The groove 156 is sized and shaped to receive a locking structure 184 of the outer shaft 106 when the outer shaft 106 is mounted on the elongated member 112 of the body 102 in a desired configuration. The groove 156 may be configured, for example, as a circular groove extending around the proximal portion 142 at a point thereon. Although the locking groove 156 is shown and described as extending around the proximal portion 142, those skilled in the art will understand that in an alternative embodiment, the locking groove 156 extends around the distal portion 144.

[0044] As described above, when the first bone screw 108 is driven into or out of the bone, the inner shaft 104 is configured to mate with the body 102 to retain the first bone screw 108. The first bone screw 108 includes a retaining structure 130 along the interior of the head portion 120. According to one example, the first bone screw 108 is a standard bone screw that includes a smooth head portion 120 and a threaded shaft portion 146, the smooth head portion being for abutting against the outer surface of the bone, and the threaded shaft portion being configured to be driven into the bone to pass through a locking hole, such as an intramedullary nail or other implant. The size and shape of the driving structure 126 are set to correspond to the driving feature 136 of the elongated member 112, and in one embodiment, the driving structure includes a hexagonal or star-shaped groove extending into the head portion 120.

[0045] The retaining structure 130 extends distally from the drive structure 126 and further distally into the head portion 120. In one embodiment, the retaining structure 130 includes a groove 148 extending from the drive structure 136, the groove 148 including threads 149 along its surface. Although the retaining structure 130 is shown and described as a threaded groove, those skilled in the art will understand that the retaining structure 130 may have any of a variety of configurations engaging the head portion 120, provided that the retaining structure 130 is configured to engage the inner shaft 104 while the first bone screw 108 is rotatably driven.

[0046] The inner shaft 104 includes a longitudinal element 105 extending from a proximal end 150 to a distal end 118 and a knob 152 attached to the proximal end 150. The proximal end 150 of the longitudinal element 105 may also include a retaining feature along the proximal end, configured to secure the inner shaft 104 to the body 102, thereby preventing unintended disassembly of the inner shaft 104 from the body 102 during handling. The distal end 118 includes a retaining feature 154 for engaging a retaining structure 130 of the first bone screw 108. In one embodiment, the retaining feature 154 is configured as a thread along the distal end 118 that engages a threaded groove 148 of the retaining structure 130 of the first bone screw 100. However, those skilled in the art will understand that the retaining feature 154 of the inner shaft 104 can have any of a variety of configurations as long as the retaining feature 154 corresponds to the retaining structure 130 of the first bone screw 108.

[0047] The longitudinal element 105 of the inner shaft 104 includes a distal portion 158 and a proximal portion 160. The size and shape of the distal portion are configured to correspond to the distal portion 144 of the channel 138 of the elongated member 112 of the body 102, and the size and shape of the proximal portion are configured to correspond to the proximal portion 142 of the channel 138. In other words, the proximal portion 160 has a larger diameter than the distal portion 158. The distal end 162 of the proximal portion 160 is configured to abut against the shoulder 140 of the channel when inserted through it. The lengths of the proximal portion 160 and the distal portion 158 are chosen such that when the longitudinal element 105 of the inner shaft 104 is inserted into the channel 138 at the distal end 162 of the distal portion 158 abutting the shoulder 140, the distal end 118 of the inner shaft 104 extends distally from the distal end 116 of the elongated member 112 by a distance corresponding to the depth of the groove 148 of the retaining structure 130 of the first bone screw 108.

[0048] When the inner shaft 104 is assembled with the body 102, the longitudinal element 105 is inserted through the channel 138 of the elongated member 112, such that the knob 152 of the inner shaft 104 extends proximally toward the shank member 114. In one embodiment, the size, shape, and configuration of the knob 152 are configured to facilitate rotation of the knob 152, thereby facilitating the distal extension of the longitudinal element 105 about its longitudinal axis, such that the retaining feature 154, threaded along its distal end 118, engages the thread 149 of the retaining structure 130 of the first bone screw 108. For example, the knob 152 can be rotated about the longitudinal axis of the longitudinal element 105 in a first (e.g., clockwise) direction to engage the retaining feature 154 of the inner shaft 104 with the retaining structure 130 of the first screw 108.

[0049] To disengage the retaining feature 154 from the retaining structure 130, the knob 152 can rotate in a second (e.g., counterclockwise) direction opposite to the first direction. The knob 152 may include a plurality of grooves 164 around its periphery to facilitate gripping the knob 152 during rotation. In one embodiment, the grooves 164 extend along the radially outermost surface 166 of the knob 152. Each groove 164 may be configured as a generally arcuate recess extending into the radially outermost surface 166, such that each groove 164 is generally symmetrical about a central axis C extending through the center of the knob 152 and between the midpoint of the first end 168 and the second end 170 of each groove 164. However, in another embodiment, as... Figure 5 As shown, each groove in the groove 164 is asymmetrical about the central axis C, and the first portion 172 of the groove 164 on the first side of the central axis has a larger radius of curvature than the second portion 174 of the groove 164 on the second side of the central axis C.

[0050] A first portion 172 of groove 164 extends along one side of groove 164 on which a force is applied when the user rotates knob 152 in a first (e.g., clockwise) direction, while a second portion 174 of groove 164 extends along one side of groove 164 on which a force is applied when the user rotates knob 152 in a second (e.g., counterclockwise) direction. In other words, the angle of the surface region of groove 164 is configured such that the resulting force vector moves radially to facilitate, for example, loosening of knob 152.

[0051] When the second bone screw 110 is inserted into or withdrawn from the bone, the outer shaft 106 can be fitted with the body 102 to retain the second bone screw 110. As described above, the retaining structure 132 of the second bone screw 110 extends around its outer surface 124. According to one example, the second bone screw 110 can be a reversibly recessed bone screw, which includes threads 190 along its entire length. The second bone screw 110 can be configured as a substantially headless screw, such that, if desired, the second bone screw 110 can be driven into the bone until the proximal end 111 of the second bone screw 110 is substantially flush with the bone.

[0052] A portion of the thread 190 extending along the proximal portion 191 of the second bone screw 110 constitutes a retaining structure 132 that can be engaged via the distal end 122 of the outer shaft 106. As described above, the second bone screw 110 also includes a drive structure 128 extending into the proximal end 111, which in one embodiment may be configured as a star-shaped or hexagonal recess such that when the drive feature 136 of the body 102 is inserted into the star-shaped or hexagonal recess and rotated about its longitudinal axis, the second bone screw 110 can be correspondingly rotated and thereby driven into the bone.

[0053] The outer shaft 106 extends from a proximal end 176 to a distal end 122 and includes a channel 178 extending through the outer shaft. The channel 178 of the outer shaft 106 is sized and shaped such that the outer shaft 106 can be mounted on an elongated member 112 of the body 102. The distal end 122 includes a retaining feature 186 configured to engage a retaining structure 132 of a second bone screw 110. In one embodiment, the retaining feature 186 includes a thread 188 extending along the channel 178 at the distal end 122, the thread 188 being configured to engage a thread 190 along a proximal portion 191 of the second bone screw 110. Similar to the longitudinal element 105 of the elongated member 112 and the inner shaft 104, the inner and outer diameters of the proximal portion 180 of the outer shaft 106 are larger than the inner and outer diameters of its distal portion 182, respectively. In this embodiment, the inner diameter of the proximal portion 180 corresponds to the outer diameter of the proximal portion 142 of the elongated member 112 of the body 102, while the inner diameter of the distal portion 182 corresponds to the outer diameter of the distal portion 144.

[0054] The proximal portion 180 includes a locking structure 184 mounted therein, which engages a locking recess 156 of the elongated member 112 of the body 102 when the outer shaft 106 is mounted on the elongated member 112 in a desired position. The locking structure 184 may be configured as a spring-loaded element biased to protrude into a channel 178 of the outer shaft 106. As the elongated member 112 slides distally through the channel 178, the locking structure 184 is radially pushed out of the channel 178 until the locking recess 156 is positioned adjacent to the locking structure 184.

[0055] At this point, the locking structure 184 moves radially outward to protrude into the channel 178 to enter the locking groove 156 under its bias. This locks the outer shaft 106 relative to the body 102 in the desired configuration. In the desired configuration, the outer shaft 106 and the elongated member 112 are longitudinally positioned relative to each other such that the drive feature 136 is positioned within the distal end 122 of the outer shaft 106. Thus, when the assembled body 102 and outer shaft 106 are connected to the second bone screw 110 to drive the second bone screw 110 into or out of the bone, the drive feature 136 of the body 102 engages the drive structure 128 of the second bone screw 110, while the thread 188 within the distal end 122 of the outer shaft 106 engages the thread 190 along the proximal portion 191 of the second bone screw 110.

[0056] Locking structure 184 and locking groove 156 engage with each other, allowing body 102 to rotate relative to outer shaft 106 about its longitudinal axis. In one embodiment, body 102 and outer shaft 106 are rotatable to drive second bone screw 110 into bone until outer shaft 106 is pressed against the surface of bone. Once outer shaft 106 is pressed against bone, body 102 is rotatable relative to outer shaft 106, such that threads 190 along the proximal portion 191 of second bone screw 110 engage bone and disengage threads 188 along the interior of the distal end 122 of outer shaft 102.

[0057] The user can rotate the body 102 while holding the outer shaft 106 at, for example, locking structure 184, allowing the body 102 to rotate relative to the outer shaft. In one embodiment, the distal end 192 of the proximal portion 180 of the outer shaft 106 is separated from the shoulder 140 of the elongated member 112 of the body 102 by a distance corresponding to the length of the thread 188 inside the distal end 122 of the outer shaft 106. Thus, when the second bone screw 110 has been driven into the bone such that the proximal end 111 is flush with the bone, the distal end 192 of the proximal portion 180 abuts against the shoulder 140, and the thread 190 along the proximal portion of the second bone screw 110 is completely disengaged from the distal end 122. In another embodiment, the body 102, the outer shaft 106, and the second screw 110 can be configured such that a predetermined number of rotations of the body 102 relative to the outer shaft 106 will disengage the second screw 110 from the body 102.

[0058] According to another embodiment, the body 102 may include markings along a portion of the elongated member 112 to indicate to the user, for example, when the head 120 of the first bone screw 108 is flush with the bone or when the proximal end 111 of the second bone screw 110 is flush with the bone. The markings may include, for example, lines, etchings, and / or grooves. In one example, such as... Figure 11 As shown, the markings may include lines 113 and 115. When the body 102 is assembled to the inner shaft 104 to drive the first bone screw 108 into the bone, the first line 113, for example, distal to the second line 115, is aligned with the guide sleeve 117 (through which the first bone screw is inserted), indicating to the user that the head 120 of the first bone screw 108 is flush with the bone. When the body 102 is assembled to the outer shaft 106 to drive the second bone screw 110 into the bone, the alignment of the second line 115 with, for example, the guide sleeve 117 will indicate to the user that the proximal end 111 of the second bone screw 110 is flush with the surface of the bone.

[0059] Those skilled in the art will understand that the outer shaft 106 may also include markings (e.g., lines) along a portion of the outer shaft to indicate that the second bone screw 110 has been driven into the bone such that the proximal end 111 is flush with its outer surface. In another embodiment, the first line marking and the second line marking 113 may also be color-coded. According to yet another embodiment, portions of the first type of bone screw 108 and the second type of bone screw 110 may be color-coded to correspond to color-coded markings along the body 102 and / or the outer shaft 106 to support ease of use when using different screw diameters. In another example, as Figures 12 to 13As shown, the markings may also include etched symbols 113a, 115a, each symbol corresponding to one of the first type of bone screw 108 and the second type of bone screw 110. For example, the symbols may include etchings showing the proximal portion of the screw relative to a line or groove to indicate to the user when the head 120 of the first bone screw 108 abuts against the bone or when the proximal end 111 of the second bone screw 110 is flush with the bone.

[0060] According to an exemplary method utilizing system 100, a user (e.g., a surgeon) selects the type of screw to be used to treat bone. If the selected screw is such as a first bone screw 108, in which the structure 130 is held along its interior, the user will assemble the body 102 with the inner shaft 104 by inserting the longitudinal element 105 of the inner shaft 104 into the channel 138 passing through the elongated member 112 of the body 102, as... Figure 2 As shown. The inner shaft 104 is inserted distally through the channel 138 until the distal end 118 of the inner shaft 104 extends distally from the distal end 116 of the body 102, such that the distal end 116 can engage with the retaining structure 130 of the first bone screw 108. In one embodiment, the inner shaft 104 is rotated about its longitudinal axis in a first direction via a knob 152 such that the threads of the retaining feature 154 along the distal end 118 thread into the corresponding threads 149 along the groove 148 of the retaining structure 130.

[0061] When the first bone screw 108 is held via the retaining feature 154, the distal end 116 of the body 102 can be inserted into the drive structure 126 within the head portion 120 of the first bone screw 108. As described above, the size and shape of the drive feature 136 at the distal end 116 of the body 102 and the drive structure 126 of the first bone screw 108 are correspondingly set such that the first bone screw 108 can be rotatably driven (e.g., into the bone to be treated) via rotation of the body 102 about its longitudinal axis. When the first bone screw 108 is rotatably driven, the first bone screw 108 is prevented from disengaging from the assembled body 102 and inner shaft 104 via the retaining feature 154. Once the first bone screw 108 has been driven into or out of the bone as needed, the inner shaft 104 can be disengaged from the bone screw 108 by rotating the inner shaft 104 relative to the first bone screw 108 in a second direction.

[0062] If the screw to be used is, for example, a second bone screw 110, in which the retaining structure 132 is held along its outer surface 124, the user assembles the body 102 to the outer shaft 106 by inserting the elongated member 112 of the body 102 distally into the channel 178 through the outer shaft 106 until the locking structure 184 of the outer shaft 106 engages along the locking groove 156 of the elongated member 112. Figure 6As shown. In one embodiment, the distal end 122 of the outer shaft 106 is engaged with the retaining structure 132 of the second bone screw 110 before locking the outer shaft 106 to the body 102, such that when the locking member 184 is received in the corresponding locking groove 156, the driving feature 136 of the body is inserted into the corresponding driving structure 128 of the second bone screw 110, which is already held by the outer shaft 106.

[0063] In one embodiment, to retain the second bone screw 110, the outer shaft 106 is rotated relative to the second bone screw 110 such that the thread 188 of the retaining feature 186 within the distal end 122 engages with the thread 190 along the outer surface 124 of the second bone screw 110. As described above, the second bone screw 110 is driven into or out of the bone via rotation of the body 102 and / or the outer shaft 106 about its longitudinal axis. In particular, the body 102 and the outer shaft 106 are rotated together to drive the second bone screw 110 into the bone until the outer shaft 106 is pressed against the surface of the bone. Once the outer shaft 106 is pressed against the bone, the body 102 is rotated relative to the outer shaft 106 to drive the proximal portion of the second bone screw 110 into the bone.

[0064] As described above, depending on the type of bone screw to be retained and driven into the bone, the body 102 can be selectively assembled with one of the inner shaft 104 and the outer shaft 106. The body 102 can be assembled with and disassembled with the inner shaft 104 and the outer shaft 106 as needed to insert various types of bone screws, including retaining features along their interior or exterior.

[0065] Although the second bone screw 110 is shown and described as a generally headless screw, wherein the second bone screw 110 can be inserted into the bone such that the proximal end 111 is flush with the bone, those skilled in the art will understand that the system 100 can be fitted with one of the inner shaft 104 or the outer shaft 106 to drive and retain a variety of different types of bone screws. In another embodiment, for example, the system 200 may be substantially similar to the system 100 described above.

[0066] In particular, such as Figure 9As shown, the bone screw 210 of system 200 may be substantially similar to the second bone screw 110 described above with respect to system 100, the bone screw 210 including a retaining structure 232 extending externally along its proximal portion. However, the bone screw 210 may be configured as a standard bone screw, which includes a head portion 291 and an axis 294 extending distally from the head portion. Similar to bone screw 110, the retaining structure 232 may include threads 290 along the head portion 291. However, instead of continuous threads along the entire length of the retaining structure, the threads 290 along the head portion 291 are separated from the threads extending along the axis 294, such that the head portion 291 cannot be driven into the bone. Similar to the second bone screw 110, the threads 290 engage a corresponding thread 288 within the distal end 222 of the outer shaft 206.

[0067] According to yet another exemplary implementation, such as Figure 10 As shown, system 300 may be substantially similar to systems 100 and 200 described above. In particular, the bone screw 310 of system 300 may be substantially similar to the bone screw 210 described above, the bone screw 310 including a retaining structure 332 along its head portion 391. However, the head portion 391 includes a tapered proximal portion 394 instead of a generally cylindrical head portion, the tapered proximal portion tapering toward the proximal end 311 of the bone screw 310 such that the thread 390 of the retaining structure 332 extends along the tapered portion 394. In this embodiment, the shape of the distal end 322 of the outer shaft 306 is correspondingly set such that a retaining feature 386 including a thread 388 extends along the corresponding tapered portion 398 at the distal end 322.

[0068] Those skilled in the art will understand that modifications and variations can be made to the structure and method of the embodiments without departing from the spirit or scope of the embodiments of the present invention. Therefore, the embodiments of the present invention are intended to cover various modifications and variations of these embodiments, provided that they fall within the scope of the appended claims or their equivalents.

Claims

1. A modular system for treating bone, comprising: The body includes an elongated member extending from a proximal end to a distal end and including a channel extending longitudinally through the elongated member, the proximal end being attached to a shank member, and the distal end including a drive feature whose size and shape are configured to engage a corresponding drive structure of one of a first bone screw and a second bone screw. The inner shaft includes a longitudinal element whose size and shape are configured to be inserted into the channel of the elongated member passing through the body, the longitudinal element extending from a proximal end to a distal end, the distal end of the longitudinal element including a retaining feature of a corresponding internal retaining structure extending within a groove for engaging at the proximal end of the first bone screw; as well as An outer shaft, extending longitudinally from a proximal end to a distal end and including a channel extending through the outer shaft, the channel being sized and shaped to slidably receive the elongated member of the body within the channel, and the channel including a retaining feature extending along its distal end, the retaining feature of the outer shaft being configured to engage an external retaining structure extending along the outer surface of the second bone screw, wherein the body is selectively fitted with one of the inner shaft and the outer shaft to drive one of the first bone screw and the second bone screw into the bone.

2. The system according to claim 1, wherein, The retaining feature of the inner shaft includes a thread extending along its distal end.

3. The system according to claim 1, wherein, The inner shaft includes a knob attached to the proximal end of the longitudinal element, which extends proximal to the handle member of the body when the inner shaft is assembled with the body.

4. The system according to claim 3, wherein, The knob includes a plurality of grooves along its outermost radial surface to facilitate gripping.

5. The system according to claim 4, wherein, Each of the plurality of grooves is asymmetrical about the central axis extending through the center of the knob and the midpoint between the first and second ends of each groove.

6. The system according to claim 5, wherein, Each of the plurality of grooves is configured as a generally arcuate groove, such that a first portion of the arcuate groove extending between the first end and the midpoint has a larger radius of curvature than a second portion of the arcuate groove extending between the second end and the midpoint.

7. The system according to claim 1, wherein, The retaining feature of the outer shaft includes a thread extending along the inner surface of the channel at the distal end of the outer shaft.

8. The system according to claim 1, wherein, The outer shaft includes a locking member comprising a tab biased into the channel of the outer shaft, and the elongated member includes a corresponding locking groove extending around a portion of the elongated member, such that when the elongated member is inserted into the channel of the outer shaft, the tab of the locking member is pushed out of the channel until the locking groove is positioned adjacent to the tab and the tab is allowed to return to its biased configuration to be received within the locking groove.

9. The system according to claim 1, wherein, The drive structure of the first bone screw and the second bone screw is configured as a first groove extending into its proximal end, the size and shape of the first groove being set to correspond to the drive feature portion of the body.

10. The system according to claim 9, wherein, The first bone screw and the second bone screw also include a second groove extending distally from the first groove, and the retaining structure of the first bone screw and the second bone screw includes threads extending along the second groove.

11. The system according to claim 1, wherein, The second bone screw includes threads that extend along its entire length.

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