Self-retaining screw and screw driver

Abstract

A bone screw insertion device comprising an outer sleeve extending from a proximal end to a distal end and including a passage extending therethrough, and a drive member extending longitudinally through the passage of the outer sleeve from a proximal end to a distal end configured to engage a drive recess of a bone screw, the outer sleeve being movable relative to the drive member between a first position in which the distal end of the outer sleeve extends over and covers a proximal portion of a bone screw engaged with the drive member and a second position in which the distal end of the outer sleeve is longitudinally aligned with a proximal end of a bone screw engaged with the drive member.

Description

Background Technology

[0001] Some long bone fractures can be treated by positioning the bone in a correct alignment and inserting an intramedullary nail into the medullary canal of the aligned bone. The intramedullary nail is fixed relative to the bone by a fixation screw inserted into a fixation hole extending laterally through the nail. The fixation screw may include, for example, a headless screw (e.g., a screw with threads along its entire length), which can be inserted such that the screw is flush with the bone. However, in some cases, the headless screw may be inserted too far into the bone, which may obstruct the intramedullary nail, cause loss of grip in the proximal cortex of the bone, and / or protrude too far from the distal cortex of the bone. Summary of the Invention

[0002] This disclosure relates to a system for treating bone. The system includes a headless screw and an insertion device. The headless screw extends from a proximal end to a distal end and includes threads extending along an outer surface of the headless screw. The headless screw includes a drive recess extending into the proximal end of the headless screw. The insertion device includes an outer sleeve and a drive member, the outer sleeve extending from the proximal end to the distal end and including a channel extending through the outer sleeve. The drive member extends longitudinally from the proximal end to the distal end through the channel in the outer sleeve. The proximal end of the drive member extends proximally to the distal end of the proximal end of the outer sleeve, the distal end being configured to engage the drive recess of the headless screw to rotatably drive the headless screw into bone. The outer sleeve is movable relative to the drive member between a first position and a second position. In the first position, when the headless screw is engaged with the drive member in an operating configuration, the distal end of the outer sleeve extends over and covers the proximal portion of the headless screw. In the second position, the distal end of the outer sleeve is longitudinally aligned with the proximal end of the headless screw.

[0003] In one embodiment, the headless screw also includes a retaining recess that extends distally from the drive recess.

[0004] In one embodiment, the insertion device further includes a retaining member extending longitudinally from a proximal end to a distal end through a channel in the drive member, the distal end being configured to engage the retaining recess such that the headless screw is held on the insertion device during insertion of the headless screw into the bone.

[0005] In one embodiment, the retaining recess includes a thread along the retaining recess, and the distal end of the retaining member is correspondingly threaded, such that rotation of the retaining member relative to the drive member about the longitudinal axis of the retaining member causes the thread of the retaining member to engage with the thread of the retaining recess, thereby retaining the headless screw on the insertion device.

[0006] In one embodiment, the proximal end of the retaining member includes a knob that extends proximal to the proximal end of the driving member to rotate the retaining member relative to the driving member.

[0007] In one embodiment, the outer sleeve includes a locking mechanism for locking the outer sleeve relative to the drive member in one of the first and second positions. The locking mechanism includes a locking tab biased toward the locking configuration via a biasing element and a push button that compresses the biasing element to move the locking tab toward the unlocking configuration.

[0008] In one embodiment, the drive member includes: a first groove extending into the outer surface of the drive member such that when the locking tab is received in the first groove, the outer sleeve is in the first position relative to the drive member; and a second groove extending proximal to the first groove into the outer surface of the drive member such that when the locking tab is received in the second groove, the outer sleeve is in the second position relative to the drive member.

[0009] In one embodiment, the core diameter of the proximal portion of the headless screw is larger than the core diameter along the remaining portion of the headless screw.

[0010] In one embodiment, the external sleeve includes gripping features extending distally from the distal end of the external sleeve, these gripping features being configured to engage the bone.

[0011] In one embodiment, the outer sleeve includes a thread along the distal end of the outer sleeve, the thread being configured to engage a corresponding thread along the proximal portion of the headless screw.

[0012] In one embodiment, the outer sleeve includes a proximal portion and a distal portion connected to each other via a friction interface, the distal portion being rotatable about the longitudinal axis of the outer sleeve.

[0013] In one embodiment, the proximal portion of the outer sleeve includes a mating feature configured to engage with a corresponding mating feature on the drive member to prevent the proximal portion from rotating relative to the drive member.

[0014] In one embodiment, the proximal portion of the external cannula includes a depth indicator indicating the depth to which the headless screw has been inserted into the bone. Additionally, this disclosure relates to a bone screw insertion device. The device includes an external cannula and a drive member, the external cannula extending from a proximal end to a distal end and including a channel extending through the external cannula. The drive member extends longitudinally from the proximal end to the distal end through the channel of the external cannula, the distal end being configured to engage a drive recess of the bone screw. The external cannula is movable relative to the drive member between a first position and a second position, in which the distal end of the external cannula extends over and covers the proximal portion of the bone screw engaged with the drive member, and in the second position, the distal end of the external cannula is longitudinally aligned with the proximal end of the bone screw engaged with the drive member.

[0015] In one embodiment, the system also includes a retaining member extending longitudinally from the proximal end to the distal end through the channel of the drive member, the retaining member being configured to releasably engage a retaining recess of the bone screw.

[0016] In one embodiment, the distal end of the retaining member is threaded to engage the corresponding thread of the retaining recess.

[0017] In one embodiment, the proximal end of the retaining member includes a knob that extends proximal to the proximal end of the driving member to rotate the retaining member relative to the driving member.

[0018] In one embodiment, the outer sleeve includes a locking mechanism for locking the outer sleeve relative to the drive member in one of the first and second positions. The locking mechanism includes a locking tab biased toward the locking configuration via a biasing element and a push button that compresses the biasing element to move the locking tab toward the unlocking configuration.

[0019] In one embodiment, the drive member includes: a first groove extending into the outer surface of the drive member such that when the locking tab is received in the first groove, the outer sleeve is in the first position relative to the drive member; and a second groove extending proximal to the first groove into the outer surface of the drive member such that when the locking tab is received in the second groove, the outer sleeve is in the second position relative to the drive member.

[0020] In one embodiment, the external sleeve includes gripping features extending distally from the distal end of the external sleeve, these gripping features being configured to engage the bone.

[0021] In one embodiment, the outer sleeve includes threads along the inner surface of the distal portion of the outer sleeve, the threads being configured to engage corresponding threads along the proximal portion of a headless screw received within the outer sleeve.

[0022] In one embodiment, the outer sleeve includes a proximal portion and a distal portion connected to each other via a friction interface, the distal portion of the outer sleeve being rotatable about the longitudinal axis of the outer sleeve relative to the proximal portion of the outer sleeve.

[0023] In one embodiment, the proximal portion of the outer sleeve includes a mating feature configured to engage with a corresponding mating feature on the drive member to prevent the proximal portion from rotating relative to the drive member.

[0024] In one embodiment, the proximal portion of the external cannula includes a depth indicator indicating the depth to which the headless screw, engaged with the drive member, has been inserted into the bone. Furthermore, this disclosure relates to a method for implanting a bone screw, the method comprising: assembling the headless screw with the insertion device by inserting a distal end of the drive member of the insertion device into a correspondingly sized and shaped drive recess of the headless bone screw; inserting the headless bone screw with the insertion device in a first position adjacent to a target region of bone, wherein in the first position, the external cannula is mounted over the drive member such that the distal end of the external cannula extends over and covers the proximal portion of the headless screw. The process involves: driving the headless screw into the bone by rotating the drive member until the distal end of the outer sleeve abuts against the proximal skin of the bone; pulling the outer sleeve proximally relative to the drive member from the first position to a second position, in which the distal side of the outer sleeve is longitudinally aligned with the proximal side of the headless screw; and further driving the headless screw distally into the bone until the distal end of the outer sleeve contacts the proximal skin of the bone, thereby providing the user with tactile feedback that the headless screw is flush with the bone.

[0025] In one embodiment, the method further includes retaining the headless screw on the insertion device by threading a threaded distal portion of a retaining member to a corresponding threaded retaining recess of the headless screw, the retaining member extending longitudinally through the drive member.

[0026] In one embodiment, pulling the outer sleeve from the first position toward the proximal side relative to the drive member to the second position includes: moving the locking mechanism of the outer sleeve from a locking configuration to an unlocking configuration, such that the locking tab of the locking mechanism can move from a first groove along the drive member to a second groove along the drive member.

[0027] In one implementation, the locking tab is biased toward the locking configuration via a bias.

[0028] In one implementation, moving the locking mechanism from the locking configuration to the unlocking configuration includes: pressing a down button to compress the biasing element, causing the locking tab to disengage from the first groove and the outer sleeve to move proximally along the drive member, and the locking tab returning to the biased configuration to engage the second groove in the second configuration.

[0029] In one embodiment, the method further includes removing the insert device from the implanted skull screw by disengaging the threaded distal portion of the retaining member from the retaining recess and pulling the insert device proximally from the retaining recess.

[0030] In one embodiment, the method further includes retaining the headless screw on the insertion device by threading the distal end of the outer sleeve to the proximal portion of the headless screw.

[0031] In one embodiment, the outer sleeve includes a proximal portion and a distal portion connected via a friction interface, the distal portion being rotatable about the longitudinal axis of the outer sleeve such that the distal portion rotates together with the drive member relative to the proximal portion of the outer sleeve.

[0032] In one embodiment, when the distal end abuts the proximal cortex of the bone, the friction interface provides feedback indicating that the proximal portion of the headless screw is driven into the bone. Attached Figure Description

[0033] Figure 1 A longitudinal sectional view of a system according to an exemplary embodiment of the present disclosure is shown;

[0034] Figure 2 It shows the basis according to Figure 1 An enlarged view of the distal portion of the insertion device and the proximal portion of the headless screw in the system;

[0035] Figure 3 It shows according to Figure 1 A longitudinal sectional view of the headless screw system;

[0036] Figure 4 It shows according to Figure 1 A longitudinal sectional view of the drive component of the insertion device of the system;

[0037] Figure 5 It shows according to Figure 1 A side view of the retaining component of the system's insertion device;

[0038] Figure 6 It shows according to Figure 1 A longitudinal sectional view of the outer sleeve of the system's insertion device;

[0039] Figure 7 It shows according to Figure 1 An enlarged cross-sectional view of the locking mechanism of the outer sleeve of the system's insertion device;

[0040] Figure 8 It shows Figure 1 A longitudinal sectional view of a portion of the system, in which the distal portion of the headless screw is inserted into the bone;

[0041] Figure 9 It shows Figure 1 A longitudinal sectional view of a portion of the system, showing the outer sleeve moving from a first position to a second position;

[0042] Figure 10 It shows Figure 1 A longitudinal sectional view of a part of the system, showing a headless screw inserted into the bone in the desired configuration;

[0043] Figure 11 A longitudinal sectional view of a portion of a system according to another exemplary embodiment of this disclosure is shown in a first position;

[0044] Figure 12 The second position is shown. Figure 11 A longitudinal sectional view of the system;

[0045] Figure 13 It shows according to Figure 11 Side view of the external sleeve of the system;

[0046] Figure 14 A partial longitudinal sectional view of a portion of a system according to another exemplary embodiment of this disclosure, in a first position, is shown;

[0047] Figure 15 The second position is shown. Figure 14 A partial longitudinal sectional view of a part of the system;

[0048] Figure 16 It shows according to Figure 14 A partial sectional view of the side view of the outer sleeve of the system;

[0049] Figure 17 It shows according to Figure 14 A side view of the driving components of the system;

[0050] Figure 18 A perspective view of a system according to yet another exemplary embodiment of this disclosure is shown; and

[0051] Figure 19It shows according to Figure 18 A plan view of the proximal end of the external sleeve of the system. Detailed Implementation

[0052] This disclosure can be further understood with reference to the following description and accompanying drawings, wherein like reference numerals refer to similar elements. This embodiment relates to the treatment of bone, and more specifically to the treatment of fractures of long bones such as the femur, tibia, humerus, etc. Once the bone is positioned in correct alignment, an intramedullary nail is inserted through the medullary canal of the bone and fixed relative to the bone by a fixation screw. Specifically, a headless screw (including threads along its entire length) is inserted through a fixation opening extending laterally through the intramedullary nail, such that the headless screw is flush with the bone.

[0053] However, in some cases, the headless screw may be inserted too far into the bone, which can cause the screw to obstruct the intramedullary nail, lose its fulcrum in the proximal cortex, and / or protrude too far from the distal cortex. An exemplary embodiment describes a system including an insertion device for the headless screw that provides tactile feedback to the user when the screw is flush with the bone, thereby preventing the screw from being inserted too far into the bone. Those skilled in the art will understand that, as used herein, the terms proximal and distal refer to the direction toward (proximal) and away from (distal) the system described herein. It should be further understood that although the embodiments described herein are directed to intramedullary nailing systems for long bones, the insertion device and headless screw of this disclosure can also be used in other bone fixation systems in which the headless screw should be inserted flush with the bone.

[0054] like Figures 1 to 10 As shown, a system 100 for treating bone includes an insertion device 102 for inserting a headless screw 104 flush with bone 10. The headless screw 104 extends longitudinally from a proximal end 106 to a distal end 108 and includes threads 110 along its entire length. The insertion device 102 may include a drive member 112 for driving the headless screw 104 into bone 10, a retaining member 114 for engaging and retaining the headless screw 104 when driven into bone 10, and an external cannula 116 for providing tactile feedback to a user (e.g., a surgeon) when the proximal end 106 of the headless screw 104 is flush with bone. Each of the drive member 112, retaining member 114, and external cannula 116 is coupled to a handle member 124 such that the drive member 112, retaining member 114, and external cannula 116 are movable relative to each other to insert the headless screw 104 into bone, as will be described in further detail below.

[0055] like Figure 3As shown, a headless screw 104 extends along a longitudinal axis from a proximal end 106 to a distal end 108. A thread 110 extends along the entire length of the headless screw 104, allowing the headless screw 104 to be inserted into the bone 10, such that the proximal end 106 is flush with the proximal skin of the bone 10. In some embodiments, the proximal portion 126 of the headless screw 104 may have a larger core diameter and / or a larger thread diameter compared to the remaining portion 128 of the headless screw 104. When the headless screw 104 is screwed (e.g., screwed into) the bone, the larger core diameter and outer diameter along the proximal portion 126 will increase the insertion torque, thereby providing the user with additional tactile feedback that the proximal portion 126 of the headless screw 104 is engaging the bone 10. Those skilled in the art will understand that the core diameter of the proximal portion 126 may be defined via the outer surface of the proximal portion 126 (to which the thread does not extend) and / or via the radially inner end of the thread extending along the proximal portion 126.

[0056] The proximal end 106 of the headless screw 104 includes a drive recess 118 that extends distally along the longitudinal axis of the headless screw 104 into the proximal end 106 of the headless screw 104. For example... Figure 3 As shown, the drive recess 118 is configured to receive a correspondingly sized and shaped engagement portion 130 of the drive member 112 of the insertion device 102. The drive recess 118 is configured such that when the engagement portion 130 of the drive member 112 is received within the drive recess and rotates about the longitudinal axis of the drive member, torque is applied to the headless screw 104 to drive the headless screw 104 into the bone 10.

[0057] In one embodiment, the drive recess 118 includes a generally circular central portion and a plurality of notches formed along the surface of the generally circular central portion, such that these notches extend radially outward from the longitudinal axis of the headless screw 104. Those skilled in the art will understand that the drive recess 118 may include any number of notches in any of a variety of configurations, as long as the notches are sized and shaped to engage corresponding portions of the engagement portion 130 of the drive member 112. Those skilled in the art will also understand that the drive recess 118 may have any of a variety of configurations, as long as the drive recess 118 can engage with the drive member 112.

[0058] For example, in another embodiment, the drive recess 118 may have a hexagonal cross-section. In another example, the drive recess 118 may be star-shaped. However, those skilled in the art will understand that the drive recess 118 may have any shape of a variety of shapes, as long as torque can be applied to the headless screw 104.

[0059] The proximal end 106 of the headless screw 104 also includes a retaining recess 120 extending distally from the driving recess 118. The retaining recess 120 has a smaller cross-sectional area compared to the driving recess 118 and is configured to receive a threaded retaining portion 133 at the distal end 132 of the retaining member 114. In one embodiment, the retaining recess 120 may include threads 134 along the inner surface 136 of the retaining recess for engaging a corresponding threaded engagement portion 133 of the retaining member 114. As will be described in further detail below, the engagement between the retaining member 114 and the retaining recess 120 facilitates retaining (e.g., holding) the headless screw 104 to the insertion device 102 when the headless screw 104 is driven into the bone 10.

[0060] As described above, the insertion device 102 includes a driving member 112, a retaining member 114, and an outer sleeve 116. Figure 4 As shown, the drive member 112 extends longitudinally from the proximal end 138 to the engagement portion 130 at the distal end 140 of the drive member, and includes a channel 142 extending longitudinally through the drive member. The proximal end 138 is connected to the handle member 124 such that when the handle member 124 is rotated about the longitudinal axis of the insertion device 102, the drive member 112 rotates accordingly to drive the headless screw 104 engaged at the engagement portion 130 into the bone 10, as will be described in further detail below. Although the drive member 112 is shown and described as including the handle member 124 at the proximal end 138, in another embodiment, the proximal end 138 may be configured such that the proximal end 138 is coupled to one of the handle member 124 and an electric actuator, such that the headless screw 104 can be manually or electrically driven into the bone as needed.

[0061] like Figure 5 As shown, the retaining member 114 extends longitudinally from the proximal end 144 to the distal end 132 and is sized and shaped to be received within the channel 142 of the drive member 112. In one embodiment, as described above, the distal end 132 includes a threaded retaining portion 133 configured to engage a corresponding thread 134 of the retaining recess 120 of the headless screw 104. The proximal end 144 of the retaining member 114 may be attached, for example, to a knob 146 that extends proximally to the proximal end 148 of the handle member 124 when the retaining member 114 is received within the channel 142.

[0062] The retaining element 114 is longitudinally movable relative to the driving member 112 between a non-retaining configuration and a retaining configuration. In the non-retaining configuration, the distal end 132 of the retaining member 114 is flush with or proximal to the distal end 140 of the driving member 112, such that the distal end 132 of the retaining member 114 does not extend distally beyond the distal end 140 of the driving member 112. Therefore, even when the driving member 112 engages with the drive recess 118 of the headless screw, the distal end 132 of the retaining member 114 does not engage the retaining recess 120 in the non-retaining configuration. However, the retaining member 114 is movable distally relative to the driving member 112 toward the retaining configuration, wherein the distal end 132 of the retaining member 114 extends distally beyond the distal end 140 of the driving member 112 to engage the retaining recess 120 of the headless screw 104.

[0063] When the distal end 132 includes a threaded retaining portion 133, the retaining member 114 can be rotated about the longitudinal axis of the retaining member in a first direction to engage the threaded engaging portion 133 with the corresponding thread 134 of the retaining recess 120. The retaining member 114 can be rotated, for example, via a knob 146. To move the retaining member 114 from a retaining configuration to a non-retaining configuration, the retaining member 114 is rotated about the longitudinal axis of the retaining member in a second direction opposite to the first direction until the threaded retaining portion 133 is unscrewed from the retaining recess 120.

[0064] like Figure 6 As shown, an outer sleeve 116 extends longitudinally from a proximal end 150 to a distal end 122 and includes a channel 152 extending through the outer sleeve. The outer sleeve 116 is slidably mounted on a drive member 112 such that the outer sleeve 116 is longitudinally movable relative to the drive member 112 between a first position and a second position. In the first position, the distal end 122 of the outer sleeve 116 extends distally beyond the distal end 140 of the drive member 112, such that when the drive recess 118 of the headless screw 104 engages with the engagement portion 130 of the drive member 112, the distal end 122 extends over and covers the proximal portion 126 of the headless screw 104. In the second position, the outer sleeve 116 is pulled proximally relative to the drive member 112 such that the distal end 122 is aligned with the proximal end 106 of the headless screw 104. Specifically, the distal surface 123 of the distal end 122 is longitudinally aligned with the proximal surface 107 of the proximal end 106 of the head screw 104.

[0065] Initially, with the external cannula 116 in a first position, the headless screw 104 is inserted into the living body until the external cannula reaches the target area of ​​the bone 10, into which the headless screw 104 is to be driven. The headless screw 104 is inserted into the body with the proximal portion 126 covered to protect surrounding tissue from the threads 110 extending along the proximal portion 126, which act as cutting grooves during implantation of the headless screw 104. After reaching the target area, the external cannula 116 is retracted to a second position, and the headless screw 104 is driven into the bone 10 until the distal side 123 of the external cannula 116 adjoins the proximal skin of the bone 10. The distance the external cannula 116 is retracted from the first position to the second position corresponds to the length of the proximal portion 126 of the headless screw 104. Therefore, when the headless screw 104 is driven into the bone 10 and the distal end 123 is adjacent to the proximal skin of the bone 10, the abutment between the outer sleeve 116 and the bone 10 provides the user with tactile feedback indicating that the proximal end 106 is flush with the bone 10.

[0066] The outer sleeve 116 of this embodiment is movable between a first position and a second position via a locking mechanism 154, which includes a locking tab 156 biased toward a locking configuration via a biasing element 158, such as Figure 7 As shown, however, those skilled in the art will understand that any mechanism allowing desired relative movement may be employed. In the locking configuration, the locking tab 156 extends into the channel 152 of the outer sleeve 116 to engage one of the first groove 160 and the second groove 162 along the outer surface of the drive member 112. When the locking tab 156 is received within the first groove 160, the outer sleeve 116 is in a first position relative to the drive member 112. When the locking tab 156 is located in the second groove 162 (which is positioned proximal to the first groove 160), the outer sleeve 116 is in a second position relative to the drive member 112.

[0067] The locking tab 156 can be moved between the first recess 160 and the second recess 162 by, for example, pressing a button 164, which, when pressed, moves the locking tab 156 out of the channel 152 and disengages it from one of the recesses 160, 162 toward the unlocking configuration. Therefore, when it is desired to move the outer sleeve 116 between the first and second positions, the user can simply press the button 164 and slide the outer sleeve 116 longitudinally proximally or distally relative to the drive member 112. When the locking tab 156 approaches the other of the first recess 160 and the second recess 162, the locking tab 156 returns to its bias locking configuration, thereby engaging the other of the first recess 160 and the second recess 162.

[0068] Although the locking mechanism 154 is shown positioned at the proximal end 150 of the outer sleeve 116, those skilled in the art will understand that the locking mechanism 154 may be positioned at any location along the length of the outer sleeve 116, provided that the locking mechanism 154 is accessible to the user during the implantation process and that the locking tab 156 can be received within the first recess 160 and the second recess 162 to allow the outer sleeve 116 to move relative to the drive member 112 between the first and second positions.

[0069] Those skilled in the art will also understand that, if necessary, a user can press down button 164 to slide the outer sleeve 116 proximally relative to the drive member 112 to remove the outer sleeve 116 from the insertion device 102. For cases where it is desired to implant the headless screw 104 distally beyond the proximal skin layer of the bone 10, removal of the outer sleeve 116 may be desired. Those skilled in the art will also understand that the outer sleeve 116 can be removed to drive a conventionally shaped bone screw, including a head. The head of a conventional bone screw may include both a drive recess and a retaining recess substantially similar to those described above as the drive recess 118 and retaining recess 120.

[0070] According to the exemplary method of this disclosure, the insertion device 102 is coupled to the headless screw 104 by inserting the engaging portion 130 of the drive member 112 into the drive recess 118 at the proximal end 106 of the headless screw 104 and engaging the distal end 132 of the retaining member 114 into the retaining recess 120 of the headless screw 104. In one embodiment, when the engaging portion 130 of the drive member 112 is inserted into the drive recess 118 of the headless screw 104, the threaded portion 133 of the retaining member 114 engages with the retaining recess 120 by rotating the retaining member distally relative to the drive member 112 and the headless screw 104 in a first direction about the longitudinal axis of the retaining member, such that the threaded retaining portion 133 threadedly engages the thread 134 of the retaining recess 120.

[0071] Initially, with the outer sleeve 116 in the first position—that is, with the distal end 122 extending over and covering the proximal portion 126 of the headless screw 104—the headless screw 104 is driven into the bone 10. The headless screw 104 is driven into the bone 10 by rotating the driving member 112 about its longitudinal axis until the distal end 122 of the outer sleeve 122 contacts the proximal skin of the bone 10 (e.g., ...). Figure 8 (as shown), thereby providing the user with first tactile feedback indicating that the distal end 128 of the headless screw 104 has been inserted into the bone 10 until the desired initial depth (e.g., until the distal end of the proximal portion of the screw 104 is adjacent to the proximal cortex of the bone).

[0072] The user then moves the outer sleeve 116 toward the proximal side relative to the drive member 112 to a second position (e.g., Figure 9 As shown), this aligns the distal side 123 of the outer sleeve 116 with the proximal side 107 of the headless screw 104. As described above, the outer sleeve 116 can then be locked in a second position relative to the drive member 112 via the locking mechanism 154. In one embodiment, after a predetermined number of full rotations of the headless screw 104 have been completed, the user knows that the distal portion 128 of the screw 104 is fully inserted into the bone. For example, it is known that two full rotations of the headless screw 104 will result in the distal portion 128 of the headless screw 104 being fully inserted into the bone 10—that is, the screw 104 has been inserted to the point where the distal end of the proximal portion 126 of the screw 104 is adjacent to the proximal skin of the bone 10.

[0073] Once the external cannula 116 is secured in the second position, the headless screw 104 is further driven into the bone 10 until the distal surface 123 is once again adjacent to the cortex, as shown. Figure 10 As shown, this allows the user to be informed via a second tactile feedback that the headless screw 104 has been inserted into the bone 10, such that the proximal end 106 is flush with the proximal skin. Given a predetermined number of turns for completing the insertion of the headless screw 104, the second tactile feedback can provide the user with confirmation that the proximal side 107 of the headless screw 104 is flush with the surface of the proximal skin.

[0074] Once the headless screw 104 is fully inserted into the bone 10, as described above, the insertion device 102 is disengaged from the headless screw 104 and removed from the body as needed, thereby keeping the headless screw 104 implanted in the bone 10. Specifically, the retaining member 114 is disengaged from the headless screw 104 by rotating the retaining member 114 about the longitudinal axis of the retaining member in a second direction until the threaded retaining portion 133 has been completely unscrewed from the retaining recess 120. Then, the driving member 112 is disengaged from the driving recess 118 by withdrawing the insertion device 102 only proximally from the headless screw 104.

[0075] Figures 11 to 13A system 200 for inserting a headless screw 204 into bone 20 is shown. As described above, system 200 facilitates the insertion of the screw 204 into a desired location, for example, where the proximal end 206 of the headless screw 204 is flush with the proximal skin of bone 20. System 200 may be substantially similar to system 100, which includes an insertion device 202 comprising an outer sleeve 216 and a drive member 212 that can slide longitudinally within the outer sleeve. Although not shown, those skilled in the art will understand that insertion device 202 may also include a retaining member substantially similar to retaining member 114 for retaining the headless screw 204 during insertion into bone. Similar to insertion device 102, the outer sleeve 216 may be positioned relative to drive member 212 as follows: Figure 11 The first initial position shown and as follows Figure 12 The external sleeve moves longitudinally between the second positions shown, indicating to the user the desired position in which the headless screw 204 has been inserted into the bone 20—for example, such that the proximal end 206 is flush with the bone 20.

[0076] However, in this embodiment, in the first position, the outer sleeve 216 extends over and covers the entire length of the headless screw 204, such that the position of the outer sleeve 216 relative to the drive member 212 in the first position is based on the selected length of the headless screw 204. Therefore, before inserting the headless screw 204 into the bone, the user can select a headless screw 204 of desired length and adjust the outer sleeve 216 to the desired first position corresponding to the length of the selected headless screw 204, as will be described in further detail below.

[0077] The headless screw 204 may be substantially similar to the bone screw 104, extending longitudinally from the proximal end 206 to the distal end 208 and including threads extending along the entire length of the headless screw. The headless screw 204 also includes a drive recess 218 extending into the proximal end 206, the drive recess 218 being sized, shaped, and configured to engage an engagement portion 230 of the drive member 212, the size and shape of which are correspondingly defined. The headless screw 204 may also include a retaining recess (not shown) substantially similar to the retaining recess of the headless screw 104.

[0078] As described above, the insertion device 202 includes an outer sleeve 216 and a drive member 212 slidably housed within the outer sleeve. The outer sleeve 216 may be substantially similar to outer sleeve 116, extending from a proximal end to a distal end 222 and including a channel 252 extending through the outer sleeve. However, the channel 252 includes a shoulder 253 positioned along the distal portion of the channel, such that, as will be described in further detail below, the shoulder 253 serves as a stop to prevent further distal movement of the drive member 212 once it is in a second position relative to the outer sleeve 216. The distal side 223 of the outer sleeve 216 may also include a plurality of teeth 266 projecting from the distal side and configured to engage the bone when the distal side 223 is pressed against the bone 20. The teeth 266 hold the insertion device 202 in a target position along the bone 20, allowing the headless screw 204 to be driven into the bone.

[0079] Drive member 212 may be substantially similar to drive member 112, extending from a proximal end to a distal end 240, and includes an engagement portion 230 sized, shaped, and configured to engage a drive recess 218 of headless screw 204. However, in this embodiment, drive member 212 also includes a plurality of recesses 260 extending longitudinally along the distal portion of the drive member. Each recess 260 extends around the circumference of the drive member and is configured to receive a locking tab 256 of locking mechanism 254, which, as will be described in further detail below, is used to secure the outer sleeve 216 and drive member 212 relative to each other in a desired first position. Each recess 260 defines a selected length of headless screw 204. For example, a first recess 260a may represent a 30 mm screw, a second adjacent recess 260b may represent a 35 mm screw, and a third recess 260c adjacent to the second recess 260b may represent a 40 mm screw, and so on.

[0080] In this embodiment, the locking mechanism 254 may include a sliding push-button 264 that is slidable along the length of the outer sleeve 216 and relative to the drive member 212, such that a locking tab 256 of the locking mechanism can engage a desired groove in a recess 260 of the drive member 212. Similar to locking tab 156, locking tab 256 may be biased toward the locking configuration via a biasing element such as a spring. Therefore, when the push-button 264 is pressed, the biasing element is compressed to disengage locking tab 256 toward the unlocking configuration, such that by sliding the locking mechanism along the length of the outer sleeve 216, locking tab 256 can move along the outer sleeve to a desired position corresponding to the desired groove in the recess 260, such as... Figure 13As shown. The depressable button 264 can then be released, causing the locking tab 256 to return to its bias configuration and engage the desired groove in the engagement recess 260 corresponding to the selected length of the headless screw 204. In this embodiment, the outer sleeve 216 includes markings 268 along the outer sleeve indicating positions corresponding to the desired length of the headless screw 204.

[0081] Once the length of the headless screw 204 has been selected and the press button 264 has been adjusted to secure the outer sleeve 216 and the drive member 212 in the corresponding first position, the headless screw 205 can be inserted into the bone. The engaging portion 230 of the drive member 212 is inserted into the drive recess 218 such that, in the first position, the outer sleeve 216 extends over and covers the entire length of the headless screw 204. In one embodiment, the distal tip of the headless screw 204 and the distal surface 223 of the outer sleeve 216 are longitudinally aligned in the first position. The insertion device 202 is then pressed distally against the target portion of the bone 20, such that the teeth 266 along the distal surface 223 of the outer sleeve 216 engage the bone 20.

[0082] Once in this target position, the drive member 212 rotates about the longitudinal axis of the drive member relative to the outer sleeve 216 and moves distally relative to the outer sleeve, causing the headless screw 204 to be driven out of the outer sleeve 216 and into the bone 20. The headless screw 204 can be driven into the bone 20 until a portion of the locking mechanism 254 abuts the shoulder 253, thereby indicating to the user that the drive member 212 and the outer sleeve 216 are in a second position relative to each other—that is, the headless screw 204 is in a desired configuration within the bone 20, in which the proximal side 207 of the headless screw 204 is flush with the proximal cortex of the bone.

[0083] like Figures 14 to 17 As shown, system 300 may be substantially similar to systems 100 and 200 as described above. This system includes an insertion device 302 for inserting a headless screw 304 into a desired location within bone 30 (e.g., where the proximal side 307 of the headless screw 304 is substantially flush with the surface of the proximal skin of bone 30). Similar to the systems described above, the insertion device 302 includes an outer sleeve 316, within which a drive member 312 is housed, as described above. Figure 14 The first initial position shown and as follows Figure 15The external cannula moves longitudinally between the second positions shown, indicating to the user the desired location of the headless screw 304 within the bone. Similar to external cannula 116, when the distal side of external cannula 316 abuts against the proximal skin of bone 30, the abutment between external cannula 316 and bone 30 provides the user with tactile feedback indicating the desired location of the headless screw 304 within bone 30. In addition to the tactile feedback indicating the desired location of the headless screw 304, insertion device 302 also provides auditory feedback, as will be described in further detail below.

[0084] The headless screw 304 is substantially similar to the headless screw 104 described above with respect to system 100. For example... Figure 16 As shown, the outer sleeve 316 is also substantially similar to the outer sleeve 116, extending from the proximal end 350 to the distal end 322 and including a channel 352 extending through the outer sleeve. The outer sleeve 116 also includes a locking mechanism 354 located at the proximal end 350, which includes a locking tab 356 biased toward a locking configuration via a biasing element 358. Figure 17 As shown, the drive member 312 is substantially similar to the drive member 112 and is configured to extend longitudinally through a channel 352 of the outer sleeve 316, and is longitudinally and rotatably movable relative to the outer sleeve to drive the headless screw 304 into the bone 30 via an engagement portion 330 at the distal end 340 of the drive member. In another configuration, the drive member 312 may have a channel extending through the drive member and configured to receive a retaining member (not shown), which, together with... Figure 5 The retaining member 114 shown is basically similar.

[0085] Similar to the insertion device 102, the locking tab 356 of the locking mechanism 354 engages the first groove 360 ​​of the driving member 312 in a first position and the second groove 362 of the driving member 312 in a second position. However, in this embodiment, when the headless screw 304 is driven into the bone toward the desired configuration, the insertion device 302 moves from the first position ( Figure 14 ) Towards the second position ( Figure 15 The locking tab 356 moves from the first groove 360 ​​toward the second groove 362 when the headless screw 304 is driven into the desired position within the bone.

[0086] In this embodiment, the ramp surface 370 extends between the first recess 360 and the second recess 362. The diameter of the ramp surface 370 increases from the distal end 372 connected to the first recess 360 to the proximal end 374 near the second recess 362. The distal end 372 has a diameter substantially the same as the first recess 360, while the proximal end 374 has a larger diameter than the second recess 362. Therefore, when the drive member 312 moves distally relative to the outer sleeve 316 to drive the headless screw 304 into the bone, the locking tab 356 slides along the ramp surface 370 from the first recess 360, and the biasing element of the locking mechanism 354 is compressed as the locking tab 356 slides along the ramp surface 370 until the locking tab 356 moves proximally beyond the proximal end 374 of the ramp surface 370 to be received within the second recess 362.

[0087] As the locking tab 356 moves proximally beyond the proximal end 374 of the ramp surface 370, the locking tab 356 returns to its biased configuration, causing the locking tab to "click" into the second groove 362, thereby providing auditory feedback to the user. The auditory feedback indicates to the user that the headless screw 304 has been fully inserted into the bone in the desired configuration, such that the proximal side 307 of the headless screw 304 is substantially flush with the surface of the bone 30.

[0088] like Figures 18 to 19 As shown, a system 400 according to another exemplary embodiment may be substantially similar to systems 100-300 described above. This system includes an insertion device 402 for driving a headless screw 404 into a desired location within the bone. The insertion device 402 includes a drive member 412 extending through an outer sleeve 416. However, instead of a separate retaining member, in this embodiment, the outer sleeve 416 includes a thread 453 extending through the distal end of a channel 452, which engages a thread 410 along a proximal portion 426 of the headless screw 404 to retain the screw 404 as it is driven into the bone. Additionally, the outer sleeve 416 includes a depth indicator 476 for indicating the insertion depth of the proximal portion 426 of the headless screw 404, allowing the user to drive the headless screw 404 into a desired location within the bone—for example, such that the proximal portion 407 of the screw 404 is flush with the bone.

[0089] Similar to outer sleeves 116-316, outer sleeve 416 extends from a proximal end 450 to a distal end 422 and includes a channel 452 extending through the outer sleeve. However, outer sleeve 416 also includes a proximal portion 478 and a distal portion 480, which have a friction interface 481, such as a ratchet mechanism. Channel 452 extends through both the proximal portion 478 and the distal portion 480. As described above, channel 452 includes a distal threaded portion 453 for engaging and retaining the headless screw 404 during insertion of the screw 404 into the bone. Similar to outer sleeve 216, the distal surface 423 of outer sleeve 416 includes teeth 466 or other gripping features configured to grip or engage the bone when the outer sleeve 416 is pressed distally against the bone.

[0090] like Figure 19 As shown, the proximal portion 478 includes a depth indicator 476 along the proximal surface 477, making the depth indicator 476 visible to the user of the insertion device 402. The depth indicator 476 indicates to the user the insertion depth of the proximal portion 426 of the headless screw 404. Those skilled in the art will understand that the length of the proximal portion 426 of the headless screw 404 will be known to the user of the device 402.

[0091] For example, in one embodiment, the proximal portion 426 of the headless screw 404 may have a length of approximately 6.25 mm, such that when the depth indicator displays the corresponding insertion depth, the user will know that the headless screw 404 has been completely countersunk. As will be described in further detail below, the proximal portion 478 also includes a mating feature 482 whose size and shape are configured to mate with a corresponding mating feature 484 of the drive member 412, such that when the mating features 482, 484 are engaged with each other, the proximal portion 478 and the drive member 412 are keyed to each other, such that the proximal portion 478 and the drive member 412 are not rotatable relative to each other.

[0092] The drive member 412 is substantially similar to the drive member described above, and includes an engagement portion 430 located at the distal end 440 of the drive member for engaging a drive recess 418 of a headless screw 404. The drive member 412 extends through a channel 452 of the outer sleeve 416 and includes a mating feature 484 such that when the mating feature 484 engages with the mating feature 482 of the proximal portion 478 of the outer sleeve 416, the proximal portion 478 and the drive member 412 are keyed to each other. In one embodiment, the mating feature 482 of the proximal portion 478 may include a longitudinal groove extending along a surface of a portion of the channel extending through the proximal portion, while a corresponding mating feature 484 of the drive shaft 412 includes a correspondingly sized and shaped protrusion extending outwardly from the drive shaft 412 to be received within the longitudinal groove of the mating feature 482 and slidable along the longitudinal groove of the mating feature. Those skilled in the art will understand that the mating features 482, 484 can have any of a variety of configurations, as long as the mating features 482, 484 bond the drive member 412 and the proximal portion 478 relative to each other to prevent the drive member 412 from rotating relative to the proximal portion 478, while allowing the drive member 412 to move distally relative to the proximal portion.

[0093] In use, the headless screw 404 is assembled with the insertion device 402 before insertion. Specifically, the outer sleeve 416 is threaded onto the proximal portion 426 of the headless screw 404, and the engaging portion 430 of the drive member 412 is inserted into the correspondingly sized and shaped drive recess 418 of the headless screw 404. The headless screw 404 is then inserted into the body and positioned over the target area of ​​the bone. The drive member 412 is then rotated to drive the headless screw 404 into the bone. Since the drive member 412 is keyed to the proximal portion 478 of the outer sleeve 416, rotation of the drive member 412 also causes rotation of the proximal portion 478. In addition, since the proximal portion 478 and the distal portion 480 of the outer sleeve 416 have a friction interface, the distal portion 480 also rotates correspondingly with the drive member 412 until the outer sleeve 416 is pressed distally against the surface of the bone.

[0094] Once the headless screw 404 has been driven sufficiently into the bone so that the outer sleeve 416 is pressed against the bone, the teeth 466 follow the distal side 423 of the outer sleeve to prevent any further rotation of the distal portion 480 of the outer sleeve 416. Therefore, as the user continues to rotate the drive member 412 to further drive the headless screw 404 into the bone, a ratchet mechanism engages between the proximal portion 478 and the distal portion 480, providing auditory feedback to the user as the proximal portion 478 rotates relative to the distal portion 480. This auditory feedback indicates that the proximal portion 426 of the headless screw 404 has begun to embed and be driven into the bone.

[0095] In one embodiment, the depth indicator 476 may indicate 0 mm of insertion when the distal portion 423 of the outer sleeve 416 first contacts the bone. However, as the user continues to rotate the drive member 412, the proximal portion 478 of the outer sleeve 416 also rotates relative to the distal portion 480, thus providing audible feedback as the depth indicator 476 displays how far the screw 404 has traveled. As the headless screw 404 is further driven into the bone, the headless screw 404 is also unscrewed from the threaded distal portion 453 of the outer sleeve 416. Once the depth indicator 476 indicates that the desired insertion depth has been achieved—that is, the desired length of the proximal portion 426 of the headless screw 404 has been inserted into the bone—the user can remove the insertion device 402 from the body, thereby keeping the headless screw 404 in the desired position implanted in the bone.

[0096] Those skilled in the art will understand that modifications and variations can be made to the structure and method of the present invention without departing from its spirit and scope. Therefore, the present invention is intended to cover various modifications and variations thereof, provided that they fall within the scope of the appended claims or their equivalents.

Claims

1. A system for treating bone, comprising: A headless screw, the headless screw extending from a proximal end to a distal end and including threads extending along the outer surface of the headless screw, the headless screw including a drive recess extending into the proximal end of the headless screw; as well as An insertion device, the insertion device comprising: an outer sleeve extending from a proximal end to a distal end and including a channel extending through the outer sleeve; A drive member extends longitudinally from a proximal end to a distal end through the channel of the outer sleeve, the proximal end of the drive member extending proximally to the distal end of the proximal end of the outer sleeve, the distal end being configured to engage the drive recess of the headless screw to rotatably drive the headless screw into the bone, the outer sleeve being movable relative to the drive member between a first position and a second position, in the first position, when the headless screw is engaged with the drive member in an operating configuration, the distal end of the outer sleeve extends over and covers the proximal portion of the headless screw, and in the second position, the distal end of the outer sleeve is longitudinally aligned with the proximal end of the headless screw, wherein the outer sleeve includes a locking mechanism for locking the outer sleeve relative to the drive member in one of the first and second positions, the locking mechanism including a locking tab biased toward the locking configuration via a biasing element and a push button that compresses the biasing element to move the locking tab toward the unlocking configuration.

2. The system of claim 1, wherein the headless screw further includes a retaining recess extending distally from the drive recess.

3. The system of claim 2, wherein the insertion device further comprises a retaining member extending longitudinally from a proximal end to a distal end through a channel of the drive member, the distal end being configured to engage the retaining recess such that the headless screw is retained on the insertion device during insertion of the headless screw into the bone.

4. The system of claim 3, wherein the retaining recess includes a thread along the retaining recess, and the distal end of the retaining member is correspondingly threaded, such that rotation of the retaining member relative to the drive member about the longitudinal axis of the retaining member causes the thread of the retaining member to engage with the thread of the retaining recess to retain the headless screw on the insertion device.

5. The system of claim 4, wherein the proximal end of the retaining member includes a knob that extends proximal to the proximal end of the driving member to rotate the retaining member relative to the driving member.

6. The system of claim 1, wherein the driving component comprises: A first groove extending into the outer surface of the drive member, such that when the locking tab is received in the first groove, the outer sleeve is in the first position relative to the drive member; and a second groove extending proximal to the first groove into the outer surface of the drive member, such that when the locking tab is received in the second groove, the outer sleeve is in the second position relative to the drive member.

7. The system of claim 1, wherein the core diameter of the proximal portion of the headless screw is greater than the core diameter along the remaining portion of the headless screw.

8. The system of claim 1, wherein the outer sleeve includes a gripping feature extending distally from the distal end of the outer sleeve, the gripping feature being configured to engage the bone.

9. The system of claim 1, wherein the outer sleeve includes a thread along the distal end of the outer sleeve, the thread being configured to engage a corresponding thread along the proximal portion of the headless screw.

10. The system of claim 9, wherein the outer sleeve includes a proximal portion and a distal portion connected to each other via a friction interface, the distal portion being rotatable about a longitudinal axis of the outer sleeve.

11. The system of claim 10, wherein the proximal portion of the outer sleeve includes a mating feature configured to engage with a corresponding mating feature on the drive member to prevent rotation of the proximal portion relative to the drive member.

12. The system of claim 10, wherein the proximal portion of the external cannula includes a depth indicator indicating the depth to which the headless screw has been inserted into the bone.

13. A bone screw insertion device, comprising: An outer sleeve extending from a proximal end to a distal end and including a channel extending through the outer sleeve; as well as A drive member extends longitudinally from a proximal end to a distal end through the channel of the outer sleeve, the distal end being configured to engage a drive recess for a bone screw. The outer sleeve is movable relative to the drive member between a first position and a second position. In the first position, the distal end of the outer sleeve extends over and covers the proximal portion of the bone screw that engages with the drive member. In the second position, the distal end of the outer sleeve is longitudinally aligned with the proximal end of the bone screw that engages with the drive member. The outer sleeve includes a locking mechanism for locking the outer sleeve relative to the drive member in one of the first and second positions. The locking mechanism includes a locking tab biased toward the locking configuration via a biasing element and a push button that compresses the biasing element to move the locking tab toward the unlocking configuration.

14. The apparatus of claim 13, further comprising: A retaining member extending longitudinally from the proximal end to the distal end through the channel of the driving member, the retaining member being configured to releasably engage a retaining recess of a bone screw.

15. The apparatus of claim 14, wherein the distal end of the retaining member is threaded to engage the corresponding thread of the retaining recess.

16. The apparatus of claim 15, wherein the proximal end of the retaining member includes a knob that extends proximal to the proximal end of the driving member to rotate the retaining member relative to the driving member.

17. The apparatus of claim 13, wherein the driving member comprises: A first groove extending into the outer surface of the drive member, such that when the locking tab is received in the first groove, the outer sleeve is in the first position relative to the drive member; and a second groove extending proximal to the first groove into the outer surface of the drive member, such that when the locking tab is received in the second groove, the outer sleeve is in the second position relative to the drive member.

18. The device of claim 13, wherein the outer sleeve includes a gripping feature extending distally from the distal end of the outer sleeve, the gripping feature being configured to engage the bone.

19. The device of claim 13, wherein the outer sleeve includes threads along the inner surface of the distal portion of the outer sleeve, the threads being configured to engage corresponding threads along the proximal portion of the headless screw received within the outer sleeve.

20. The apparatus of claim 19, wherein the outer sleeve includes a proximal portion and a distal portion connected to each other via a friction interface, the distal portion of the outer sleeve being rotatable about a longitudinal axis of the outer sleeve relative to the proximal portion of the outer sleeve.

21. The apparatus of claim 20, wherein the proximal portion of the outer sleeve includes a mating feature configured to engage with a corresponding mating feature on the drive member to prevent rotation of the proximal portion relative to the drive member.

22. The device of claim 20, wherein the proximal portion of the outer sleeve includes a depth indicator indicating the depth to which the headless screw engaged with the drive member has been inserted into the bone.

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