Abstract: System and methods for channeling a path into bone include a trocar having a proximal end, distal end and a central channel disposed along a central axis of the trocar. The trocar includes a distal opening at or near the distal end of the trocar. The system includes a curved cannula sized to be received in the central channel, and having a curved distal end configured to be extended laterally outward from the distal opening in a curved path extending away from the trocar. The curved cannula has a central passageway having a diameter configured to allow a probe to be delivered through the central passageway to a location beyond the curved path.

Abstract: Bone anchors and surgical instruments (e.g., bone taps, drivers, etc.) are disclosed herein that include integrated guide tips. Use of these anchors or instruments can eliminate one or more of the steps in a conventional bone anchor installation procedure, improving surgical efficiency and safety. For example, a surgical instrument can include a guide projection configured for insertion through a cannulation formed in a bone anchor when the surgical instrument is coupled to the bone anchor. The surgical instrument can also include various mechanisms for adjusting the position of the guide projection relative to the bone anchor. The guide projection can replace the needle, stylet, and guidewire used in typical insertion procedures. The bone anchor can also include integrated tapping features to eliminate the need for a separate bone tap instrument. Thus, in some embodiments, targeting, tapping, and driving the bone anchor can be performed in a single step.

Abstract: An anchor delivery system includes both a straight and curved drill guide along with a flexible drill, a flexible obturator and a flexible anchor inserter. The curved drill guide has a distal tip with approximately a 15° bend from the primary axis of the drill guide. Both the drill and the obturator have a reduced diameter section to improve flexibility during passage through the curved drill guide. Additionally, a surface of the inserter shaft has a laser cut pattern which permits flexing of the inserter around the inner diameter of the curved drill guide.

Abstract: A multi-diameter fixation pin, such as a K-wire can be used during an orthopedic procedure. The multi-diameter fixation pin may include a leading diameter sized for the specific orthopedic procedure being undertaken and/or the size of the bone into which the fixation pin is being inserted. The multi-diameter fixation pin may include a trailing diameter different than the leading diameter. The trailing diameter may be sized for use with a specific sized powered driver. For example, in orthopedic procedures that involve inserting larger diameter pins and smaller diameter pins into bone(s), all pins used in the procedure may have a trailing diameter (e.g., the larger diameter or the smaller diameter) that allows the pins to be inserted with the same powered driver (e.g., the same attachment head) without needing different sized drivers or attachment heads for different sized pins.

Abstract: A coracoid guiding system. The coracoid guiding system includes a coracoid grasper for holding an exteriorized coracoid bone block, and a coracoid passer. The coracoid passer has a pair of external barrels, a pair of internal barrel pins, a hollow guiding tube including an inner surface and an outer surface, and a hook gauge. The hook gauge is configured to be retractably arranged inside the hollow guiding tube. The hook gauge has a proximal end, a distal end, a curved section between the proximal end and the distal end, a first straight section extending from the proximal end to the curved section, a second straight section extending from the curved section to the distal end, wherein the distal end of the hook gauge is shaped as a hook.

Abstract: Various methods and devices are provided for tensioning a tether. In one embodiment, a tether tensioning device is provided and includes an elongate shaft adapted to be positioned adjacent to a bone anchor implanted in bone, and a tensioning mechanism pivotally associated with the elongate shaft and adapted to couple to a tether seated across the bone anchor and to pivot relative to the elongate shaft to apply a tensioning force to the tether.

Abstract: Tether tensioning instruments, such as instruments used to tension and/or lock a tether about a spinal feature to assist in spinal fixation, and related methods and systems. In some embodiments, the instrument may comprise a handle, a tensioner base coupled with the handle, at least a portion thereof being movably coupled to the handle, and a tether coupling member coupled with the tensioner base and configured to fixedly engage a tether. The instrument may further comprise a tensioner tip movably coupled with the tensioner base, wherein at least a portion of the tensioner base is biased away from the tensioner tip, and wherein the instrument is configured to allow for step-wise movement of the tensioner tip away from the tensioner base to increase tension between the tether and an element of the spinal fixation system.

Abstract: A cerclage cable system is disclosed which includes a bone plate, one or more securing devices, and one or more cerclage cables. The bone plate includes a plurality of bone plate apertures thereupon, wherein the bone plate is configured to be affixed to a bone. The one or more securing devices include a body having a proximal end and a distal end, wherein at least one securing device aperture is disposed toward the proximal end, wherein the distal end of the securing device is configured to be inserted into and received by the plurality of bone plate apertures. The one or more cerclage cables include two terminal ends, wherein the one or more cerclage cables are wrapped around the bone, wherein one terminal end of the one or more cerclage cables is passed through at least one securing device aperture.

Abstract: A method of bone fixation includes placing a bone plate adjacent to a lesser trochanter on a medial aspect of a femur such that at least a portion of the lesser trochanter is positioned between appendages of the bone plate, wrapping cables coupled to the bone plate about a first and second bone fragment of a proximal femur, and tightening the cables to secure the first and second bone fragments together.

Abstract: A delivery tool includes a tubular distal tip fixed to a distal end of a delivery tube. A retention portion of an implant wire of an implant is removably disposed within the tubular distal tip. A pull wire has a distal end portion that is shaped so as to define a pull-wire loop and is removably disposed partially within the delivery tube. A safety wire is removably disposed partially within the tubular distal tip, with a distal portion of the safety wire passing through a tip distal opening. The safety wire has a proximal end portion that is shaped so as to define a safety-wire hook hooked on the pull-wire loop. Proximal pulling on the pull wire proximally retracts the safety wire from the tip distal opening, thereby allowing the retention portion to pass through the tubular distal tip. Other embodiments are also described.

Abstract: Implant tensioning and/or implant anchor deployment devices are described. Certain embodiments may be recognized in the form of a so-called tensioning “gun.” Other embodiments take a simpler and more compact form. Various optional features are described in connection with these embodiments. Optional aspects of anchor embodiments for the subject implants are also described. Some of these features are coordinated for use with the implant tensioning and anchor deployment instrument, others are not.

Abstract: A system and method for installation of a k-wire through a scaphoid or other fractured bone can include a guide block for accurate trajectory of a k-wire. A support frame for a guide block can be casted and/or secured into place, and a CT scan is obtained, so the fractured bone and the location of the window can be known in the same three-dimensional space. An ideal k-wire trajectory can be plotted through the fractured bone, and a guide block with a lumen can be designed and printed using a three-dimensional printer. The guide block can be inserted into the frame so the lumen aligns with the ideal k-wire trajectory, and a k-wire can be inserted through the lumen into the fractured bone. The net effect would be ideal placement of the k-wire that would facilitate the ultimate insertion of a percutaneous screw to provide fixation of the fractured bone.

Abstract: In one embodiment, an adjustable implant system includes a bone anchor having first and second ends, a bone engagement surface adjacent the first end, and a housing extending between the first and second ends. The adjustable implant system can further include a non-invasively actuatable driving element within the housing and coupled to an adjustment component configured to couple to a flexible elongate tension member which is capable of engaging a patient's soft tissue (e.g., rotator cuff or ACL). Non-invasive actuation of the driving element can cause the adjustment component to change the amount of tension on the flexible elongate tension member and consequently on the patient's soft tissue. The adjustable implant system can include an external adjustment device configured to be placed on or adjacent the patient's skin and comprising at least one energy transferring component configured to energize/actuate the driving element inside the housing of the adjustable implant.

Abstract: Robotic system and methods for robotic arthroplasty are provided. The robotic system includes a machining system and a guidance system. The guidance station tracks movement of one or more of various objects in the operating room, such as a surgical tool, a tibia of a patient, a talus of the patient, or a component of an implant. The guidance system tracks these objects for purposes of displaying their relative positions and orientations to the surgeon and, in some cases, for purposes of controlling movement of the surgical tool of the machining system relative to virtual cutting boundaries or other virtual objects associated with the tibia and talus to facilitate preparation of bone to receive an ankle implant system.

Abstract: This disclosure concerns suburethral and pelvic support structures which utilize tissue soldering materials instead of, or in addition to, traditional tissue anchors and suture knots. It further concerns methods of treating patients that includes implanting these structures and activating the tissue soldering materials to attach the structures to a tissue in the body of the patient.

Abstract: An instrument for bending a surgical rod includes first and second arm assemblies. The first arm assembly includes first and second arms having respective first and second receiving portions configured to receive the surgical rod therein. The second arm assembly includes third and fourth arms having respective third and fourth receiving portions configured to receive the surgical rod therein. The instrument is reconfigurable from an initial configuration in which the first and third receiving portions of the respective first and third arms engage the surgical rod such that spreading of the first and third receiving portions in a first direction bends the surgical rod in a first orientation and spreading of the first and third receiving portions in a second direction bends the surgical rod in a second orientation opposite to the first orientation.

Abstract: A medical device system may include an elongate shaft having a lumen extending from a proximal end to a distal end, a proximal release wire, and a distal release wire. The proximal release wire may extend distally from a proximal end configured to remain outside the body to a distal end and may be slidably disposed within the lumen of the elongate shaft. The distal release wire may extend distally from a proximal end to a distal end and may be slidably disposed within the lumen of the elongate shaft. The proximal end of the distal release wire may be slidably coupled to the distal end of the proximal release wire. The distal release wire may be configured to releasably attach a medical device to the distal end of the elongate shaft.

Abstract: A suture transport system is disclosure for placing a flexible member along a tunnel, the system including a means of transporting a flexible member along a tunnel from a first opening in the tunnel through to a second opening at an opposite end of the tunnel, such that the flexible member extends from both the first and second opening. The system also includes a means of capturing a portion of the flexible member at the second opening, to inhibit the flexible member from retracting into the tunnel second opening. The means of capturing includes an aperture for capturing the portion of the flexible member.

Abstract: A joint stabilization (reduction) system and associated methods and tools for placement of the system in an open or minimally invasive technique. The joint stabilization system includes a flexible prosthetic band for stabilizing the bones in proper position and a connector mechanism for joining the two ends of the prosthetic band around the bones. One end of the prosthetic band can be permanently attached to the connector.

Abstract: A method of, and apparatus for, directing an elongate flexible component with a length through a part of a human body. The method includes the steps of: obtaining an apparatus having an elongate body with a length between axially spaced leading and trailing ends and a notch through a peripheral surface of the elongate body; directing a midlength part of the elongate flexible component into the notch to place the elongate flexible component into an operative position on the apparatus; and with the elongate flexible component in the operative position, advancing the elongate body through the part of the human body and thereby causing a portion of the elongate flexible component to be drawn by a drawing surface on the elongate body through the part of the human body.

Abstract: The present application generally relates to orthopedic stabilization systems, and in particular, to systems including clamps. The clamps can be used in addition to or to replace hooks that grasp onto bone members, such as the lamina. One example of such a clamp is an in-line clamp that includes a central opening for receiving a rod member, a first opening for receiving a set screw and a second opening for receiving an elastic member therethrough. Another example of such a clamp is an off-set clamp that includes an upper plate, a bottom plate, and an opening for receiving a rod therein. The upper plate can be separated from the bottom plate to make space for an elastic member that can be secured within the plates. Tulip clamps that utilize one or more elastic members are also provided.

Abstract: A spinal fixation device is provided, comprising a body member having a first side and an opposite second side, and an elongate flexible strap having a first section and a second section. The first section of the strap is attached or attachable to attachment means of the body member arranged at a first location thereof. The second section of the strap is sized and shaped to pass through a passageway arranged at a second location of the body member. The strap has a series of teeth and the passageway of the body member has a latch configured for engaging one of the teeth. The teeth and the latch are configured to allow a movement of the second section of the strap through the passageway in a tightening direction from the first side to the second side of the body member, and to prevent a movement of the second section in the opposite direction.

Abstract: A method and apparatus are provided for transtendinous implantation of a toggle-type bone anchor. Measured from the top surface of the tendon, the entire bone anchor is inserted to a depth of greater than or equal to 20 mm. during a rotator cuff repair on the humeral head. The anchor is pushed by the same bone punch that formed the initial hole to assure proper depth of placement. Further, the apparatus includes a nub portion that, in use, protrudes into the bone hole formed by the bone punch and maintains registration with the bone hole when the bone punch is retracted. An angled distal end on the anchor initiates toggling during insertion into the bone and at least one proximal projecting fin prevents the anchor from backing out of the bone hole while facilitating further rotation of the anchor when a suture is pulled to complete toggling.

Abstract: A toggle-type suture anchor that incorporates individual suture tensioning and locking without knot tying. The anchor includes an elongate toggle body having a working suture pre-threaded into a first passage and back up and out a second passage with a length running longitudinally adjacent the side of the anchor. A locking suture loop is pre-threaded into a third passage between the first and second passage and includes a collapsible loop that encircles a portion of the length of suture running longitudinally adjacent the side of the anchor. With the loop open, the working suture can slide through the anchor, however, when the loop is closed the working suture is locked in position to retain tension on the working suture. The anchor can be utilized in a pre-strung connected array of anchors.

Abstract: A system for implanting an anchor into bone, the system comprising a curved cannulated guide for percutaneous insertion, having a proximal end and a distal end; a flexible drill insertable through the curved guide from the proximal end to the distal end, the flexible drill having a shaft having a flexible portion; and a flexible inserter for inserting a suture anchor into a bore at the anatomical site formed by the flexible drill, the flexible inserter having a shaft having a flexible portion, wherein the flexible portions of both the flexible drill and flexible inserter include a series of discrete, interlocking segments.

Abstract: System and methods for channeling a path into bone include a trocar having a proximal end, distal end and a central channel disposed along a central axis of the trocar. The trocar includes a distal opening at or near the distal end of the trocar. The system includes a curved cannula sized to be received in the central channel, and having a curved distal end configured to be extended laterally outward from the distal opening in a curved path extending away from the trocar. The curved cannula has a central passageway having a diameter configured allow a probe to be delivered through the central passageway to a location beyond the curved path.

Abstract: Provided is a device for tensioning a wire in conjunction with an external bone fixation (EBF) device. A swivel hinge body comprises two forks extending in a plane parallel from the swivel hinge body. A lower lip extends from the swivel hinge body below and in parallel with the two forks. A swivel pin and a swivel block are positioned between the lower lip and the plane of the two forks and held in place by the swivel pin such that the swivel block is able to rotate in an arc with respect to the lower lip and the swivel hinge body. The swivel block comprises a face, wherein the face is configured to fit against an edge of a component of the EBF device such that, when the tensioning mechanism is applying tension to the wire, the swivel hinge body is prevented from deflecting to one side.

Abstract: An apparatus and technique for infernally securing a plurality of bone segments together. The device incorporates a plate-like structure stabilizing the fracture and integrated fasteners to attach straps circumscribing the bone segments.

Abstract: System and methods for channeling a path into bone include a trocar having a proximal end, distal end and a central channel disposed along a central axis of the trocar. The trocar includes a distal opening at or near the distal end of the trocar. The system includes a curved cannula sized to be received in the central channel, and having a curved distal end configured to be extended laterally outward from the distal opening in a curved path extending away from the trocar. The curved cannula has a central passageway having a diameter configured allow a probe to be delivered through the central passageway to a location beyond the curved path.

Abstract: A dynamic longitudinal connecting member assembly includes an anchor member having an integral or otherwise fixed elongate core of circular or non-circular cross-section. The core is pre-tensioned and extends through at least one elastic spacer and at least one outer sleeve. The anchor member and the outer sleeve each attach to at least one bone anchor. In operation, the core is held in tension by the spacer.

Abstract: A surgical instrument comprises a first arm including a first closed loop engageable with a first spinal implant disposed with a first vertebral surface. A second arm is movable relative to the first arm and includes a second closed loop engageable with a second spinal implant disposed with a second vertebral surface. Surgical systems, constructs, implants and methods are disclosed.

Abstract: A translaminar pedicle anchor suspension system (referred as T-PAS system) applicable to vertebral surgeries is disclosed. The T-PAS system comprises: at least one pedicle anchor capable of being fixed to a pedicle of a lower vertebral segment, at least one suspension ligament having one end thereof fixed to the pedicle anchor, and at least one washer capable of fixing the other end of the suspension ligament to a contralateral side of a lamina of an upper vertebral segment. By using the suspension ligament to suspend the upper vertebral segment via a tunnel drilled on the lamina, not only the spine can be dynamically stabilized, but also the use of traditional pedicle screws and bone fusion can be avoided.

Abstract: System and methods for channeling a path into bone include a trocar having a proximal end, distal end and a central channel disposed along a central axis of the trocar. The trocar includes a distal opening at or near the distal end of the trocar. The system includes a curved cannula sized to be received in the central channel, and having a curved distal end configured to be extended laterally outward from the distal opening in a curved path extending away from the trocar. The curved cannula has a central passageway having a diameter configured allow a probe to be delivered through the central passageway to a location beyond the curved path.

Abstract: A dacryocystorhinostomy (DCR) tool (10) includes a perforating shaft (30) having a distal perforating tip (32) configured to form a bypass between a lacrimal sac and a nasal cavity through a lateral side of the lacrimal sac, a lacrimal bone, and nasal mucosa. A DCR guide (20) includes a nasal guide component (40) configured to be inserted into the nasal cavity and having a distal guide tip (42); and a lacrimal guide component (50) shaped so as to define a guide channel (52) that orients the DCR guide (20) with respect to the distal perforating tip (32) during advancing of the distal perforating tip (32) through a lacrimal passageway and into the lacrimal sac, until contact of the distal perforating tip (32) with the distal guide tip (42) blocks further advancing of the distal perforating tip (32). The DCR guide (20) constrains the distal guide tip (42) to fall in a path of advancement of the distal perforating tip (32). Other embodiments are also described.

Abstract: In one example, an implant holder supports a guiding connector that attaches to a vertebrae and that secures to an elongated support member by a cable tie. The implant holder has a handle portion that has a shaft that extends between proximal and distal ends of the handle portion. The distal end of the handle portion can be positioned proximate to the guiding connector when the guiding connector is supported by the implant holder. The implant holder has at least one holder defining a channel therethrough that receives the shaft of the handle portion such that the at least one holder is slidable along the shaft. The at least one holder secures the cable tie and at least one wing of the guiding connector to the handle portion.

Abstract: A method for treating a spine comprising the steps of: connecting at least one first fastener that defines an implant cavity with at least one vertebral level of a first portion of vertebrae; connecting at least one second fastener with at least one vertebral level of a second portion of the vertebrae; manipulating the vertebrae; manipulating a spinal rod to a selected configuration; connecting the spinal rod with the at least one first fastener such that the spinal rod is disposed at a selected position with the implant cavity; connecting a tether to a second fastener and the spinal rod; and reducing the spinal rod to a selected position relative to the second fastener with the tether. Systems, spinal constructs and surgical instruments are disclosed.

Abstract: A system for reduction of vertebral bodies (or vertebrae) various embodiments includes a reducer, and extender, and a hollow tube. The reducer couples to the extender, which in turn couples to an elongated member, such as a rod, and to a bone fastener assembly. The reducer allows reduction of the vertebral body incrementally, and by a desired amount. The reducer may include or may be used in conjunction with a holding device or holder in order to hold or keep the amount of reduction constant or steady once the desired amount of reduction has been obtained. The reducer may use one of several embodiments, including embodiments that use threaded assemblies or members, inclining members or wedges, offset cams, scissor jacks, and/or levers.

Abstract: A clamp assembly for orthopedic use having a housing that includes a top surface, a recess, a distal base and a bottom surface, the recess defining a longitudinal axis and extending through the housing from the top surface through the distal base and toward the bottom surface, and at least two through slots, each one of being disposed at a bottom or a side a surface of the housing. The assembly including a securement assembly positionable within the recess in a co-axial relationship to a mating surface on the recess, and a band sized for travel along a predetermined path defined in part by the through slots in the housing, wherein at least one of the through slots is a starting point for travel of the band along the predetermined path.

Abstract: A device for correcting a placement of a guide wire in a bone includes a body extending from a proximal end to a distal end; a central channel extending through the body from the proximal end to the distal end along a central axis, the central channel sized and shaped to receive a guide wire slidably therein; and a first correction channel extending through the body from the proximal end to the distal end. The first correction channel is sized and shaped to receive a guide wire therein at an angle relative to the central axis of the central axis of the central channel.

Abstract: A wire tensioner tip includes a body having a first extension and a second extension spaced apart to define a ring slot. An engagement body is disposed within the ring receiving slot. The engagement body includes one or more projections configured to engage an outer surface of a ring positioned within the ring receiving slot. A coupling element extends from the body and is configured to couple the body to a wire tensioner.

Abstract: Guides, devices, instruments, and systems for fixing a fractured bone are disclosed. An insertion guide includes a handle member and a guide member coupled to a second end of the handle member. The guide member being curved relative to the longitudinal axis of the handle member. A bone fixation system including an insertion guide, a guide wire and a fastener. The insertion guide including a handle member and a guide member coupled to an end of the handle member. The guide member being curved and including a through hole for receiving the guide wire. The fastener including a cannulation for receiving the guide wire. Methods of using a bone fixation systems for fixing fractured bones are also disclosed.

Abstract: A minimally invasive bone fracture positioning device includes a sleeve, a movable unit, and a support. The sleeve includes an alignment portion located on a longitudinal axis of the sleeve. The movable unit includes a positioning portion. The positioning portion is located on the longitudinal axis and is spaced from the alignment portion. The movable unit is mounted in a radial direction of the sleeve. The movable unit is slideable relative to the sleeve along the longitudinal axis. A support is coupled to the sleeve and the movable unit. The movable unit is spaced from the sleeve by the support.

Abstract: Devices and methods for implantation of an orthopedic device between skeletal segments using limited surgical dissection. The implanted devices are used to adjust and maintain the spatial relationship(s) of adjacent bones. Depending on the implant design, the motion between the skeletal segments may be increased, limited, modified, or completely immobilized.

Abstract: Devices, systems, and methods are provided for ligament repair procedures, and can be used to establish a location and trajectory for forming a bone tunnel in bone. One exemplary embodiment of a surgical guide for using in a ligament repair procedure includes a guide arm and a carriage that can be selectively locked along the guide arm to define an angle of the bone tunnel. The guide arm also defines a location of a distal end of the bone tunnel. In some embodiments the carriage is configured to have a bullet side-loaded into it, and the bullet can be used to define a location of a proximal end of the bone tunnel. The present disclosure also provides for a gage that limits the distance a drill pin that drills the bone tunnel can travel. A variety of other, devices, systems, and methods are also provided.

Abstract: An orthopedic implant system includes a wedge implant. The implant includes a body having an upper surface extending generally in a first plane. The upper surface has a first plurality of longitudinal grooves and a second plurality of transverse grooves extending therealong. Portions of the upper surface extend between adjacent longitudinal grooves and transverse grooves form individual peaks. A lower surface extends generally in a second plane, parallel to the first plane. The lower surface has a third plurality of longitudinal grooves and a fourth plurality of transverse grooves extending therealong. Portions of the lower surface extend between adjacent longitudinal grooves and transverse grooves form individual peaks.

Abstract: Various methods and devices are provided for tensioning a tether. In one embodiment, a tether tensioning device is provided and includes an elongate shaft adapted to be positioned adjacent to a bone anchor implanted in bone, and a tensioning mechanism pivotally associated with the elongate shaft and adapted to couple to a tether seated across the bone anchor and to pivot relative to the elongate shaft to apply a tensioning force to the tether.

Abstract: The invention relates to a suturing device used to place sutures inside the human body during various medical procedures. The suturing device includes an elongate body member, a needle deployment mechanism and a needle receiving portion. The elongate body member has a distal portion that defines an opening. The needle deployment mechanism is disposed at least partially within the elongate body member for moving a needle out of the opening at the distal portion of the elongate body member into a tissue; and the needle receiving portion is provided at the distal portion of the elongate body member to capture the needle. The needle receiving portion has a non-planar surface with walls that are non-parallel with respect to a longitudinal direction of the needle receiving portion such that the walls converge to form an aperture formed in the needle receiving portion to receive the needle.

Abstract: This disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An example medical device may include a medical device for delivery of a surgical closure member. The medical device includes an elongate tubular member having a proximal end, a distal end and a lumen extending therein. The elongate tubular member is adapted to be delivered through the working channel of an endoscope and the lumen is adapted to receive a surgical closure member. The medical device also includes a tissue support extending from the distal end of the elongate tubular member. The tissue support includes a support surface and the support surface is adapted to support tissue as a surgical closure member engages the tissue thereon.

Abstract: Scoliosis can be treated by systems for anterior vertebral body tethering described herein. In some embodiments, installation tools of a system for anterior vertebral body tethering can be used to sequentially tension segments of a tether between adjacent vertebral screws in a controllable and user-friendly manner.

Abstract: A cable-lock device includes a housing, having a length-axis between a distal end for accepting a cable and a proximal end for exiting a cable, including a first bore parallel to the length-axis of the housing and configured to allow passage of the cable, a second bore off-center from and parallel to the first bore including a tappet axially displaceable in the second bore and parallel to the length axis of the housing, and a third bore oblique to the first bore which intersects with the first bore including a locking roller axially displaceable in the third bore with a predetermined angulation to the length-axis of the housing, a resilient structure which exerts a force on the locking roller in the direction of the intersection of the first bore and the third bore, and a fastener unit at the proximal end of the third bore.