Orthopedic implant and apparatus for delivering the same

Abstract

The present disclosure provides techniques for cross-fixation using a combination of a fracture fixation implant and a guide wire having at least two diameters, e.g., a dual-diameter guide wire.SOLUTION: A fracture treatment system may include a pair of implants that are guided by at least one guide wire 2900 having at least two diameters and cross-fixed inside the medullary canal of a bone. The present system not only prevents rotation of the fracture site, but also allows for more precise adjustment of the implant length required to achieve bicortical retention for improved stability. This more precise sizing and cross-locking placement of the implants can also allow the ends of the implants to be recessed below or flush with the outer surface of the bone, thereby reducing the risk of infection.SELECTED DRAWING: Figure 29B

Description

[Technical Field]

[0001] Any and all applications identifying foreign or domestic priority claims in the Application Data Sheet filed with this application are incorporated herein by reference in accordance with 37 CFR 1.57. This application claims the benefit of priority to U.S. Provisional Application No. 63 / 261,028, filed September 9, 2021, which is incorporated herein by reference in its entirety.

[0002] TECHNICAL FIELD The present disclosure relates to systems and methods for treating bone fractures, particularly small bone fractures. [Background technology]

[0003] Hand and foot injuries are common. For example, approximately 20% of all emergency department visits are due to traumatic finger injuries. These injuries can include sports and work-related injuries.

[0004] Fractures of the phalanges and metacarpals are among the most common skeletal injuries. Fractures are estimated to occur at a national incidence of 12.5% ​​for phalanges and 8.4% for metacarpals per 10,000 people per year. Such fractures can be inconvenient or debilitating to the patient. For example, lost productivity associated with phalange fractures is estimated to exceed $2 billion annually in the United States.

[0005] The primary goal of treating phalangeal and metacarpal fractures is to restore the anatomy of the injured bone and maintain its function as quickly as possible. Fractures of small bones, such as phalangeal and metacarpal fractures, can be treated with, for example, K-wires, intraosseous wires, cuff wires, compression screws, fixation plates, or external fixation. Some of these procedures are performed percutaneously, i.e., through the skin. Summary of the Invention [Problem to be solved by the invention]

[0006] The current standard of care for small bone fractures can result in disadvantages such as poor rotational control, delayed mobility, prolonged stiffness, reduced range of motion, soft tissue irritation, increased surgical exposure, and postoperative tendon adhesions.

[0007] Better rotational control and / or bone reduction can be achieved with an implant that retains both cortical walls (sometimes referred to as "bicortical purchase"). Currently, this procedure is performed using commercially available K-wires that are cross-locked. However, the use of commercially available K-wires results in at least one end of these K-wires protruding from the bone surface. The protruding end of the K-wire can lead to pin-site infection. [Means for solving the problem]

[0008] The present disclosure can improve surgical outcomes with cross-fixation techniques using a combination of a fracture fixation implant and a guidewire having at least two diameters, e.g., a dual-diameter guidewire. The fracture fixation systems disclosed herein can be delivered percutaneously, avoiding the need for open reduction. The fracture fixation systems and delivery methods disclosed herein can reduce and / or minimize surgical time, recovery time, and / or infection, and can speed return to activity. The fracture fixation systems and delivery methods disclosed herein can also restore anatomical structures and allow mobilization of the injured digit (finger or toe) as soon as fracture stability allows. The fracture fixation systems and delivery methods disclosed herein can further minimize soft tissue damage and / or impingement.

[0009] The fracture fixation system of the present disclosure can include two intramedullary fixation implants, which can be threaded and guided by a customized guidewire with at least two diameters to be cross-secured within the medullary canal. Alternatively, the two implants can be implanted substantially parallel to one another. This system not only prevents rotation at the fracture site, but also allows for more precise adjustment of the implant length needed to achieve bicortical purchase for improved stability. This more precise sizing and implant placement also allows both the distal and proximal ends of the implants to be flush with or recessed below the outer surface of the cortical wall, thereby reducing the risk of infection. The fixation implants can also be designed to reduce migration after implantation, for example, by having a non-smooth outer shaft surface due to threads or other means.

[0010] In the present disclosure, an exemplary guidewire having at least two diameters and configured to carry a cannulated orthopedic implant comprises a first portion having a first generally uniform outer diameter and a second portion, the second portion including at least a first segment and a second segment, the first segment having a second generally uniform outer diameter greater than the first generally uniform outer diameter, and the second segment having a third outer diameter smaller than the second outer diameter, the cannulated orthopedic implant may be configured to be slidably mounted over the first portion of the guidewire, the second generally uniform outer diameter being substantially identical to a minor diameter, root diameter or outer diameter of a shaft of the cannulated orthopedic implant.

[0011] In one configuration, the free end of the second portion may include a sharp tip.

[0012] In one configuration, the first generally uniform outer diameter may be between 0.7 mm and 0.9 mm.

[0013] In one configuration, the second generally uniform outer diameter may be between 1.5 mm and 2.0 mm.

[0014] In one configuration, the first segment and the second segment may be separated by a third segment, the outer diameter of the third segment transitioning from the third outer diameter to the second outer diameter.

[0015] In one configuration, the first portion and the second portion may be removably connected.

[0016] In one configuration, the second portion can include a cannulation configured to receive the first portion.

[0017] In one configuration, the cannulation can extend along the entire length of the second portion.

[0018] In one configuration, the cannulation can extend along a partial length of the second portion.

[0019] In one configuration, one of the first and second portions may include a hook, and the other of the first and second portions may include a loop.

[0020] A method for delivering an at least partially cannulated, threaded elongate orthopedic implant into a bone can use any of the various guidewire configurations described above, and can include using a second portion of a guidewire having any of the various configurations described above, preparing a passageway within the bone having a diameter substantially the same as a minor diameter or root diameter of the threaded elongate orthopedic implant, inserting the first portion of the guidewire into the cannulation of the implant, and inserting the implant through the passageway, guided by the first portion of the guidewire.

[0021] In the present disclosure, an exemplary method of intramedullary fracture fixation may include delivering a guidewire having at least two diameters across a fractured portion of a fractured bone, the guidewire having a first trailing end portion having a first diameter and a second leading end portion including at least a first segment and a second segment, the first segment having a second diameter greater than the first diameter and the second segment having a third outer diameter less than the second outer diameter, the delivering step including delivering the second portion of the guidewire across the medullary canal of the bone until a leading tip of the guidewire is substantially flush with an outer surface of the bone. The method may include extending the guide wire, selecting a cannulated elongate implant by determining a length of the cannulated elongate implant based on the position of the guide wire in the bone, slidably mounting the cannulated elongate implant onto the first portion of the guide wire, inserting the cannulated elongate implant guided by the guide wire into the bone so that both ends of the cannulated elongate implant do not protrude from the outer surface of the bone, and removing the guide wire from the bone.

[0022] In the present disclosure, an exemplary intramedullary fixation method may include delivering a first guidewire having at least two diameters across a fractured portion of a fractured bone, the first guidewire having a first trailing end portion having a first diameter and a second leading end portion having a second diameter greater than the first diameter, the delivering step including extending the second portion of the first guidewire across the medullary canal of the bone until a leading end of the first guidewire is substantially flush with an outer surface of the bone; selecting a first cannulated elongate implant by determining a length of the first cannulated elongate implant based on the position of the inner wire; slidably mounting the first cannulated elongate implant over the first portion of the first guide wire; inserting the first cannulated elongate implant guided by the first guide wire into the bone; removing the first guide wire from the bone; and inserting the first cannulated elongate implant across at least a fractured portion of the fractured bone. and delivering a second guidewire having two diameters, the second guidewire having a first trailing end portion having the first diameter and a second leading end portion having the second diameter larger than the first diameter, the delivering step including extending the second portion of the second guidewire across the medullary canal of the bone until a leading tip of the second guidewire is substantially flush with the outer surface of the bone; and determining a length of a second cannulated elongated implant based on a position of the second guidewire in the bone. the root diameter surface of the first implant may contact the root diameter surface of the second implant.

[0023] In one configuration, each of the first cannulated elongate implant and the second cannulated elongate implant may be bicortical.

[0024] In one configuration, the first cannulated elongate implant and the second cannulated elongate implant can each terminate at or in front of the outer surface of the bone.

[0025] In one configuration, both ends of each of the first cannulated elongate implant and the second cannulated elongate implant may not protrude into the tissue surrounding the bone.

[0026] In one configuration, the step of delivering the second guidewire may be performed after the step of removing the first guidewire from the bone.

[0027] In one configuration, the step of delivering the second guidewire may be performed after the step of delivering the first guidewire and before the step of inserting the first cannulated elongate implant.

[0028] In one configuration, the step of delivering the second guide wire may include extending the second leading end portion of the second guide wire across the medullary canal of the bone in a cross pattern with the tunnel in the bone formed by the second leading end portion of the first guide wire.

[0029] In one configuration, the step of delivering the second guide wire can include extending the second leading end portion of the second guide wire across the medullary canal of the bone substantially parallel to a tunnel in the bone formed by the second leading end portion of the first guide wire.

[0030] In one configuration, the first cannulated elongate implant and / or the second cannulated elongate implant can include threads, the threads in the middle portion having a larger pitch than the threads at or around the driver head or the leading tip.

[0031] In one configuration, the maximum outer diameter at an intermediate portion of the first cannulated elongate implant and / or the second cannulated elongate implant may be smaller than the maximum outer diameter at or around the driver head or the leading tip.

[0032] In the present disclosure, an exemplary kit for an intramedullary fracture system may include a cannulated first elongate implant having a first implant shaft outer diameter and a first implant cannulation diameter, and a guidewire that may have at least two diameters and is configured to carry the first implant inside a fractured bone for intramedullary fixation. The guidewire may include a first trailing end portion having a first diameter and a second distal portion including at least a first segment and a second segment, the first segment having a second diameter greater than the first diameter, the second segment having a third outer diameter less than the second outer diameter, the second outer diameter being substantially the same as the outer diameter of the first implant shaft (or a root or minor diameter of the first implant), the first implant cannulation diameter being configured to accommodate the first portion of the guidewire, and the kit may further include a guidewire that may have at least two diameters and is configured to carry the first implant inside a fractured bone for intramedullary fixation. and a second elongate implant configured to be co-implanted with the first implant, the second elongate implant being cannulated and having a second implant shaft outer diameter (or a second implant minor or minor diameter) and a second implant shaft cannulation diameter, the second diameter of the guidewire may be substantially the same as the second implant shaft outer diameter or minor or minor diameter of the second implant, and the second implant cannulation diameter may be configured to accommodate the first portion of the guidewire.

[0033] In one configuration, the kit may include a second guide wire configured to deliver the second implant into the fractured bone for intramedullary fixation and having at least two diameters, the second guide wire having a first trailing end portion having the first diameter and a second leading end portion having the second diameter larger than the first diameter, the second diameter being substantially the same as the outer diameter of the second implant shaft or the root diameter or minor diameter of the second implant, and the second implant cannulation diameter configured to accommodate the first portion of the second guide wire.

[0034] In one configuration, the first elongate implant and / or the second elongate implant may be threaded.

[0035] In one configuration, the second elongate implant may be configured to be implanted in a crisscross pattern with the first implant.

[0036] In one configuration, the second elongate implant can be configured to be implanted substantially parallel to the first implant.

[0037] A surgical kit may be used to perform fracture fixation using a cannulated implant, which may include a head and an at least partially threaded shaft, including a guidewire having at least two diameters configured to guide delivery of the implant into a fractured bone, the guidewire having a first trailing end portion having a first diameter, and a second leading end portion including at least a first segment having a second diameter greater than the first diameter and substantially the same as a minor diameter of the shaft of the implant, and a second segment having a third outer diameter less than the second outer diameter; The first diameter of the first portion may include a guide wire configured to slidably engage the cannulation of the implant, a sizing tool, and a driver configured to engage the head of the implant to insert the implant into the bone.

[0038] In one configuration, the surgical kit may further comprise a sterile and sealed package, and the guide wire, the sizing tool, and the driver may be enclosed within the sterile and sealed package.

[0039] In one configuration, the guidewire, the sizing tool, and / or the driver may be configured for a single use.

[0040] In one configuration, the guidewire, the sizing tool, and / or the driver may be reused by being sterilized after each use.

[0041] For purposes of summary, certain aspects, advantages and novel features are described herein. Of course, it should be understood that not all such aspects, advantages or features need be present in any particular embodiment. [Brief explanation of the drawings]

[0042] These and other features, aspects, and advantages of the present disclosure will be described with reference to the drawings illustrating specific embodiments, which are intended to illustrate specific embodiments in a schematic manner and are not intended to limit the disclosure. [Figure 1] FIG. 1 shows an x-ray of prior art crossed and fixed K-wires implanted in a finger bone. [Figure 2A] FIG. 2A shows a side view of an example implant of the present disclosure. [Figure 2B]FIG. 2B shows a cross-sectional view of the implant of FIG. 2A along its longitudinal axis (axis BB). [Figure 2C] FIG. 2C shows a posterior end view of the implant of FIG. 2A. [Figure 2D] FIG. 2D shows a front end view of the implant of FIG. 2A. [Figure 2E] FIG. 2E shows a partial cross-sectional view of the implant of FIG. 2A along axis CC. [Figure 2F] FIG. 2F shows a partial cross-sectional view of the implant of FIG. 2A along axis AA. [Figure 3A] FIG. 3A shows a side view of an unthreaded (also referred to as a "blank") version of the implant of FIG. 2A. [Figure 3B] FIG. 3B shows a front-end view of an unthreaded (also called a "blank") version of the implant of FIG. 2A. [Figure 4A] FIG. 4A shows a perspective view of an exemplary customized guidewire having at least two diameters. [Figure 4B] FIG. 4B shows a side view of the guidewire of FIG. 4A. [Figure 4C] FIG. 4C shows a front end view of the guidewire of FIG. 4A. [Figure 5A] FIG. 5A shows a front view of an exemplary sizing tool for use in delivering the device of FIG. 2A. [Figure 5B] FIG. 5B shows a side view of the sizing tool of FIG. 5A. [Figure 5C] FIG. 5C shows an end view of the sizing tool of FIG. 5A. [Figure 5D] FIG. 5D shows a detailed view of a portion of the sizing tool of FIG. 5A. [Figure 6A] FIG. 6A shows an exploded view of an exemplary driver configured to deliver the implant of FIG. 2A. [Figure 6B] FIG. 6B shows a front view of the driver of FIG. 6A. [Figure 6C] FIG. 6C shows a detailed view of the driver head portion of the driver of FIG. 6A. [Figure 6D] FIG. 6D shows a cross-sectional view of the driver head portion in detail along axis BB of FIG. 6C. [Figure 7A] FIG. 7A shows a side view of another exemplary implant of the present disclosure. [Figure 7B] FIG. 7B shows a posterior end view of the implant of FIG. 7A. [Figure 7C] FIG. 7C shows a front end view of the implant of FIG. 7A. [Figure 7D] FIG. 7D shows a cross-sectional view of the implant of FIG. 7A along its longitudinal axis (axis BB). [Figure 8A] FIG. 8A illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8B] FIG. 8B illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8C] FIG. 8C illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8D] FIG. 8D illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8E] FIG. 8E illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8F] FIG. 8F illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 8G] FIG. 8G illustrates certain steps of an exemplary method for implementing the implant of FIG. 2A. [Figure 9A] FIG. 9A illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 9B] FIG. 9B illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 9C] FIG. 9C illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 9D] FIG. 9D illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 9E] FIG. 9E illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 9F] FIG. 9F illustrates certain steps of another exemplary method for implementing the implant of FIG. 2A. [Figure 10] FIG. 10 schematically illustrates another exemplary method of implementing the implant of FIG. 2A. [Figure 11A] FIG. 11A illustrates a schematic of exemplary leg screw fixation for various metacarpal and phalangeal fractures. [Figure 11B] FIG. 11B illustrates a schematic of exemplary leg screw fixation for various metacarpal and phalangeal fractures. [Figure 11C] FIG. 11C illustrates a schematic of exemplary leg screw fixation for various metacarpal and phalangeal fractures. [Figure 12A] FIG. 12A illustrates an exemplary problem for a conventional lag screw implantation procedure. [Figure 12B] FIG. 12B illustrates an exemplary problem for a conventional lag screw implantation procedure. [Figure 12C] FIG. 12C illustrates an exemplary problem for a conventional lag screw implantation procedure. [Figure 12D] FIG. 12D illustrates an exemplary problem for a conventional lag screw implantation procedure. [Figure 13] FIG. 13 illustrates an exemplary lag screw coupled to a stepped guidewire as disclosed herein. [Figure 14A] FIG. 14A illustrates certain steps of an exemplary method for implementing the lag screw of FIG. [Figure 14B] FIG. 14B illustrates certain steps of an exemplary method for implementing the lag screw of FIG. [Figure 14C] FIG. 14C illustrates certain steps of an exemplary method for implementing the lag screw of FIG. [Figure 14D] FIG. 14D illustrates certain steps of an exemplary method for implementing the lag screw of FIG. [Figure 14E] FIG. 14E illustrates certain steps of an exemplary method for implementing the lag screw of FIG. [Figure 15] FIG. 15 illustrates a schematic of exemplary packaging for the implants and surgical tools disclosed herein. [Figure 16] FIG. 16 shows an x-ray image of a lag screw implanted with an intramedullary implant in a metacarpal bone. [Figure 17A] FIG. 17A shows an exemplary lag screw for various fixations of bones in the foot. [Figure 17B] FIG. 17B shows an exemplary lag screw for various fixations of bones in the foot. [Figure 18A] FIG. 18A illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 18B] FIG. 18B illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 19] FIG. 19 illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 20] FIG. 20 illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 21A] FIG. 21A illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 21B] FIG. 21B illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 22A] FIG. 22A illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 22B]FIG. 22B illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 22C] FIG. 22C illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 23] FIG. 23 illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 24] FIG. 24 illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 25A] FIG. 25A illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 25B] FIG. 25B illustrates an exemplary alternative delivery tool to a stepped guidewire for delivering the implants disclosed herein. [Figure 26A] FIG. 26A shows the two implants of FIG. 2A inserted with their outer diameters touching (also known as "thread-to-thread"). [Figure 26B] FIG. 26B shows two implants of another design inserted with their root diameters touching. [Figure 26C] FIG. 26C illustrates an exemplary implant configured to reduce the overall profile of the implant. [Figure 26D] FIG. 26D illustrates an exemplary implant configured to reduce the overall profile of the implant. [Figure 26E] FIG. 26E illustrates an exemplary implant configured to reduce the overall profile of the implant. [Figure 26F] FIG. 26F illustrates an exemplary implant configured to reduce the overall profile of the implant. [Figure 27A]FIG. 27A shows an exemplary guidewire having laser markings configured to promote ease of sizing. [Figure 27B] FIG. 27B illustrates an exemplary guidewire having laser markings configured to facilitate easy sizing. [Figure 28A] FIG. 28A shows an exemplary sizing tool having a guidewire engaging feature at its tip. [Figure 28B] FIG. 28B shows an exemplary sizing tool having a guidewire engaging feature at its tip. [Figure 28C] FIG. 28C shows an exemplary sizing tool having a guidewire engaging feature at its tip. [Figure 28D] FIG. 28D shows an exemplary sizing tool having a guidewire engaging feature at its tip. [Figure 29A] FIG. 29A shows a side view of a guidewire having a second portion of an alternative design. [Figure 29B] FIG. 29B shows a perspective view of the guidewire of FIG. 29A. [Figure 29C] FIG. 29C shows an enlarged view of the second portion of FIG. 29A. [Figure 29D] FIG. 29D shows various exemplary alternative designs for the second portion of the guidewire. [Figure 29E] FIG. 29E shows various exemplary alternative designs for the second portion of the guidewire. [Figure 30A] FIG. 30A shows an exemplary alternative design of the guidewire of FIG. 29A that includes cutting grooves. [Figure 30B] FIG. 30B shows an enlarged view of the second portion of FIG. 30A. [Figure 30C] FIG. 30C shows a detailed view of the distal section of the guidewire of FIG. 30A. [Figure 30D] FIG. 30D shows an end view of the guidewire of FIG. 30A. [Figure 30E] FIG. 30E shows a cross-sectional view of the guidewire along the BB axis of FIG. 30C. [Figure 30F] FIG. 30F shows a detailed perspective view of the distal section of the guidewire of FIG. 30A. [Figure 31A] FIG. 31A shows an exemplary alternative design of the guidewire shown in FIG. 29A that includes a diamond-shaped tip as the sharp tip. [Figure 31B] FIG. 31B shows a detailed front view of the diamond-shaped tip. [Figure 31C] FIG. 31C shows a side perspective view of the guidewire of FIG. 31A. [Figure 31D] FIG. 31D shows a side view of the diamond-shaped tip. [Figure 32A] FIG. 32A shows an exemplary distal tip of a guidewire of the present disclosure. [Figure 32B] FIG. 32B shows an exemplary distal tip of a guidewire of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0043] While various specific embodiments and examples are described below, those skilled in the art will recognize that such disclosure may extend beyond the specifically disclosed various embodiments and / or applications, as well as various obvious modifications and equivalents thereto. For example, the illustrated cross-locked intramedullary fixation system may also be implanted in bones in other parts of the human body, such as the foot. Thus, it is not intended that the scope of the disclosure herein be limited by any specific embodiments described below.

[0044] In the treatment of bone fractures, a single long intramedullary implant may not have sufficient rotational control when used to stabilize a fractured bone, such as a decaphalange. The fractured finger tends to spin around the longitudinal axis of the implant. It is beneficial that the implant resists rotation and does not protrude from the bone into the soft tissue, and it is also beneficial that the implant is strong enough to allow patients to regain function in their fractured finger more quickly than with current standard treatments. Better rotational control and / or bone reduction can be achieved with two cross-locked intramedullary implants, each with bicortical purchase, that each retain both cortical walls of the bone. Alternatively, two implants, each with bicortical purchase, can be implanted substantially parallel to one another.

[0045] Currently, cross-fixation procedures are performed using standard, commercially available K-wires. Such K-wires can have an outer diameter between about 1.1 mm (0.045 inches) and about 1.6 mm (0.060 inches). FIG. 1 shows the implantation of a pair of standard cross-fixation K-wires 2, 4 to treat a fractured phalanx 6 in a person's hand. However, the results with these standard cross-fixation K-wires 2, 4 are unsatisfactory for a number of reasons. For example, the K-wires 2, 4 have a generally uniform outer shaft diameter and a relatively smooth outer surface, and therefore have poor bone purchase. Due to this poor bone purchase, the K-wires 2, 4 can easily become displaced after surgery.

[0046] The unsatisfactory results may be due to the fact that the length of the K-wires 2, 4 cannot be properly adjusted to the size of the phalanges 6. When a K-wire is inserted to treat a fractured bone, it penetrates the skin, fascia, fat, tendons, periosteum, etc. before reaching the bone. As shown in FIG. 1 , when the K-wires 2, 4 are implanted across the cortical walls on approximately diametrically opposite sides 8, 10 of the phalanges 6 and across the medullary canal 9, portions of the posterior ends 12, 14 of the K-wires 2, 4 penetrate the skin and are exposed. Portions of the anterior ends 16, 18 of the K-wires 2, 4 may also protrude outward from the outer surface 20 of the phalanges 6, i.e., extend beyond the outer surface 20 of the phalanges 6. The exposed portions of the posterior ends 12, 14 that penetrate the skin can be cut off using wire cutters. However, the K-wires 2, 4 still extend from the outer surface 20 of the phalanges 6 at the posterior ends 12, 14. The anterior ends 16, 18 and / or posterior ends 12, 14 of the K-wires 2, 4 may therefore protrude from the outer surface 20 of the phalangeal bone 6 by at least about 1 mm to about 2 mm. Due to the protruding anterior ends 16, 18 and / or posterior ends 12, 14 of the K-wires 2, 4 protruding from the outer surface 20 of the bone 6, a wound may form between the bone and the skin. The tissue layers surrounding the bone 6 may slip against the wound, which may result in adhesion of the tissue layers. Furthermore, the severed posterior ends 12, 14 of the K-wires may still be exposed in the skin wound, potentially resulting in pin-site infection. In one study, metacarpal fractures treated with exposed K-wires were twice as likely to result in pin-site infection (8.7% of cases with embedded K-wires vs. 17.6% of cases with exposed K-wires).

[0047] Due to inadequate fixation and / or the need to reduce the incidence of tissue damage or pin site infection, the fractured finger may need to be further immobilized with a cast after implantation of the cross-locked K-wires, which may cause further inconvenience to the patient and may further delay healing of the fractured bone.

[0048] To improve bone retention of fixation implants, threaded implants, such as screws, may be used. Such screws may need to be delivered via multiple K-wires and therefore may require cannulation. A cannulated delivery technique can make the surgical procedure safer and easier because the delivery path can be guided by a pre-inserted guide wire, such as a K-wire. K-wires suitable for this cannulated technique preferably have an outer diameter of at least approximately 1.1 mm. K-wires with an outer diameter smaller than 1.1 mm have less rigidity and are too flexible, making them less likely to advance properly when inserted into the bone using a driver and more likely to deviate from a linear path relative to the bone. However, standard cannulated screws available commercially may have diameters that are too large for use in intramedullary fixation of phalanges or other hand and / or foot bones. This is because screws require a shaft outer diameter of greater than approximately 2.8 mm to approximately 3 mm to have sufficient cannulation size to accommodate K-wires with an outer diameter of at least approximately 1.1 mm. However, screws with shaft outer diameters of at least 2.8 mm provide insufficient space for a crisscross locking pattern (sometimes called a "crossover pattern") in small bones such as the phalanges. While the wall thickness of such screw shafts can be reduced or reduced to provide more space, for example, from about 2.8 mm to less than 2.5 mm, the reduced screw will not have sufficient length to achieve bicortical retention in the phalanges when implanted in a crossover locking pattern. This is because the maximum allowable length of the screw depends on the wall thickness of the screw shaft. Longer screws require greater wall thickness to maintain the structural rigidity and strength of the screw.

[0049] The present disclosure provides an exemplary system of threaded and / or cannulated cross-locking fixation implants with desired dimensions suitable for intramedullary fixation of phalanges (and other ossicles), including bicortical retention and improved rotational control. The present disclosure also provides exemplary devices, including but not limited to, customized guidewires with at least two diameters, allowing for easier adjustment of the length of the fixation implant and easier delivery of the implant.

[0050] Exemplary Intramedullary Fixation Systems Figures 2A through 2F illustrate an exemplary, non-limiting orthopedic implant 100. Figures 3A and 3B illustrate a blank version of the implant 100 of Figures 2A through 2F, with the blank shown with screws omitted to more clearly show certain features of the implant 100.

[0051] Implant 100 can be formed from any suitable material, such as titanium, stainless steel, or other metals and / or alloys. As shown, implant 100 has a leading end 102 and a trailing end 104. The overall length between leading end 102 and trailing end 104 can be, for example, between about 10 mm and about 50 mm, between about 12 mm and about 48 mm, between about 20 mm and about 48 mm, between about 24 mm and about 46 mm, between about 28 mm and about 44 mm, between about 32 mm and about 42 mm, or between about 36 mm and about 40 mm. All ranges provided in this disclosure are inclusive of their endpoints.

[0052] Implant 100 may include a through cannulation 120 along its longitudinal axis A to accommodate a delivery guidewire (e.g., guidewire 400 in FIGS. 4A-4C, described in detail below). Through cannulation 120 may have an inner diameter that may be, for example, less than about 1 mm, between 0.80 mm and about 0.96 mm, or between about 0.84 mm and about 0.94 mm.

[0053] The shaft 106 can extend from the leading end 102 toward the trailing end 104. As shown in FIG. 3A , the shaft 106 can have a uniform (maximum) outer diameter D throughout, except for the distal portion 108 (see FIG. 2F ). The outer diameter D can be less than about 2.5 mm, less than about 2.4 mm, less than about 2.2 mm, less than about 2.1 mm, or less than about 2.0 mm. The distal portion 108 can taper from the outer diameter D to a smaller diameter. The distal portion 108 can have a length of, for example, less than about 2 mm or less than about 1.5 mm. As shown in FIG. 2A , the distal portion 108 can include one or more cutting features, such as one or more cutting flutes. The taper and / or cutting features of the distal portion 108 can make it easier to insert the implant 100 into bone, for example, into a pre-formed tunnel in bone.

[0054] A driver head portion 112 may be disposed adjacent to the shaft 106 at the rear end 104. The driver head portion 112 may be, for example, less than about 4.0 mm or less than 3.5 mm. As shown in FIGS. 2E and 3A, the driver head portion 112 may include a tapered portion 114 that transitions from the outer diameter of the driver head portion 112 to the outer diameter D of the shaft 116. The outer diameter of the driver head portion 112 may be, for example, less than about 3.0 mm, between about 2.5 mm and about 3.0 mm, or between about 2.6 mm and about 2.9 mm. As shown in FIG. 2A, the driver head portion 112 may include one or more cutting features 116, such as one or more cutting flutes, that may be disposed throughout most or at least partially along the tapered portion 114.

[0055] The driver head portion 112 may include a driver interface, such as a hexagonal interface 118 as shown in FIG. 2C . The hexagonal interface 118 may include an inner diameter that is larger than the outer diameter of the throughbore 120. The driver interface allows torque to be transmitted from a driver (e.g., the driver 600 shown in FIGS. 6A-6D , described in detail below) to the implant 100 for delivery into the bone. Alternatively, the driver interface may be a slot interface 718 in the driver head portion 712 of the implant 700 as shown in FIGS. 7A-7D . The implant 700 may include any of the features of the implant 100 disclosed herein, and for the sake of brevity, the description of which will not be repeated here. The driver interface may alternatively accept other suitable driver configurations, such as a Torx drive, Pozidriv, Robertson, tri-wing, torque set, spanner head, triple square, etc.

[0056] The implant 100 can be threaded. As shown in FIGS. 2A and 2B , the threads 122 can extend along the entire length of the shaft 106 or substantially the entire length of the shaft 106. Optionally, the threads 122 can extend (wholly or at least partially) along the driver head portion 112. The thread height can be lower at the driver head portion 112 than at the shaft 106. The shaft 106 can have a uniform thread height such that the shaft has a generally uniform root or minor diameter. The threads 122 along the shaft 106 can have a suitable thread height (e.g., between about 0.15 mm and about 0.30 mm, between about 0.20 mm and about 0.25 mm, etc.) and / or pitch (e.g., between about 0.5 mm and about 1.0 mm, between about 0.7 mm and about 0.8 mm, etc.). The implant 100 can be a non-compression implant, or alternatively, a compression implant when compression is indicated, such as for fixation of a transverse midshaft fracture. The one or more grooves in the leading end 108 and driver head portion 112 described above can interrupt the threads 122, thereby discontinuing the threads 122 and optionally providing serrations in the grooves. The interruption and / or serrations in the threads 122 in the one or more grooves facilitate delivery of the implant 100 into the bone. Alternatively, the implant 100 can be non-threaded. Non-threaded implants can optionally include other features protruding from the outer surface of the implant, such as spikes, ridges, barbs, uneven or roughened surfaces, and / or the like, to enhance bone retention.

[0057] The threads of the implant can have a generally constant pitch or a varying thread pitch. Various variations of the threads are described with reference to Figures 26A to 26F. The implants 2600, 2600C, 2600D, 2600E, and 2600F shown in Figures 26B through 26F can have any of the features of the implants 100 disclosed herein. The threads 122 can have a pitch such that when two implants 100 are inserted into bone (such as by using the methods described below), the threads 122 of the two implants 100 meet, as shown in Figure 26A, for example. Alternatively, as shown in Figure 26B, the threads 2622 of the implants 2600 can have a pitch such that when the two implants 2600 are inserted, the implants 2600 meet at their root diameter surfaces 2621. The root-to-root contact further reduces the profile of the implants, which can be desirable when inserting the implants into small bones with small medullary canals, such as the phalanges. Valley-to-valley contact can reduce the profile of these implants by, for example, between about 15% and about 40%, between about 20% and about 35%, or between about 30% and about 35%. The minimum diameter of the implant valleys can be maintained, thereby maintaining the structural integrity and strength of the implant.

[0058] Implants can vary in maximum diameter and / or thread pitch to reduce the overall profile of the implant in the bone. Figures 26B through 26F show exemplary implants capable of reducing the profile. Features of implants 2600, 2600C, 2600D, 2600E, and 2600F can be integrated within one another. The dimensions shown in Figures 26C through 26F are for illustrative purposes only and are not intended to be limiting. For example, the overall threads of implants 2600D and 2600E can have a thread pitch large enough to allow root-to-root contact. Alternatively, for example, implants 2600, 2600F may have a larger thread pitch in the middle portion 2624 of the shaft to allow valley-to-valley contact when the two implants are inserted into an ossicle, such as a phalange, and implants 2600, 2600F may have a smaller or finer pitch at or around the driver head portion 2612 and leading end 2602 to improve fixation strength between the implant and cortical bone. Alternatively or additionally, implants 2600C, 2600E may have a smaller maximum diameter at the middle portion 2624 of the shaft than at or around the driver head portion and leading end of the implant to reduce the profile of the implant. Having a larger thread pitch and / or a smaller maximum diameter at (e.g., only at) the middle portion 2624 of the screw may reduce the profile of the implant while improving fixation strength between the implant and cortical bone and not compromising the structural rigidity of the implant. As shown in Figures 26C to 26F, the screws or portions of the screws of implants 2600C, 2600D, 2600E, and 2600F (e.g., only at the two ends of the implant or only near the two ends of the implant) may optionally be dual-lead.In FIG. 26F, by having a dual lead at the driver head portion 2612 and front end 2602 and a single lead at the middle portion 2624, the screw can be finer at the driver head portion 2612 and front end 2602 and larger at the middle portion 2624.

[0059] Non-limiting examples of guidewires for delivering the implants disclosed herein (and variations thereof in accordance with the present disclosure) are shown in Figures 4A-4C and 29A-32B. Particular features of the guidewire may be present in particular embodiments of the guidewire. However, guidewires with at least two diameters in the present disclosure may include features of any of the various embodiments of guidewires disclosed herein.

[0060] As shown in FIGS. 4A-4C, the guidewire 400 can be formed of any suitable material, such as the same materials described above for a standard K-wire. The guidewire 400 can include a leading end 402 and a trailing end 404. The leading end 402 of the guidewire can include a sharpened tip 412, which can be, for example, a trocar tip with a three-sided cut tip, as shown in FIG. 4C, or can have any other shape. The sharpened tip 412 facilitates insertion of the guidewire 400 into the bone through the leading end 402. The sharpened tip at the leading end of the guidewire can have a different size and / or shape than the trocar shown in FIG. 4C. As shown in FIG. 32A, the trocar tip 3212 can be smaller in size than the trocar tip 412 also shown in FIG. 32B. As shown in Figures 31A-31D, the sharpened tip 3112 of the guidewire 3100 may incorporate any other feature of the various guidewires disclosed herein, and may include a diamond-style tip.

[0061] The guidewire 400 may include a first portion 406 having a generally uniform first diameter D1 and a second portion 408 having a generally uniform second diameter D2. The first portion 406 may be closer to the trailing end 404, and the second portion 408 may be closer to the leading end 402. The first portion 406 may extend from the trailing end 404. A transition portion 410 (also referred to herein as a "wire shoulder") may join the first portion 406 to the second portion 408. In some implementations, the transition portion may have a zero length, with the first portion 406 transitioning to the second portion 408 via a step transition. The transition portion may have a length greater than the transition portion 410 shown in FIGS. 4A and 4B. Compared to the transition section 410 as shown in FIGS. 4A and 4B, longer exemplary transition sections 2910, 3010 are shown in FIGS. 29A-29D and 30A-30B in different variations of guidewire 400.

[0062] D1 can be configured to allow the first portion 406 to slidably receive the implant 100 through the through cannulation 120. D1 can be, for example, less than about 1 mm, less than about 0.8 mm, or between about 0.7 mm and about 0.8 mm. D2 is preferably greater than D1 and greater than the inner diameter of the through cannulation 120. D2 can be similar to or substantially the same as the outer diameter D of the implant 100. D2 can be, for example, greater than about 1 mm, greater than about 1.1 mm, between about 1.2 mm and about 2.5 mm, or between about 1.5 mm and about 2.0 mm.

[0063] The second portion of the guidewire may have multiple diameters. For example, as shown in FIGS. 29A-29E , the second portion 2908 of the guidewire 2900 may include a first segment 2914 and a second segment 2918. The first segment 2914 may be adjacent to a transition portion 2914. The first segment 2914 may have the second diameter D2 described above. The second segment 2918 may be adjacent to the sharp tip 2912. The second segment 2918 may have a third diameter D3 greater than D2. The second segment 2918 may have a substantially uniform diameter. D3 may be greater than or less than D1. D3 may be, for example, between about 0.6 mm and about 1.5 mm, between about 0.8 mm and about 1.2 mm, or between about 0.9 mm and about 1.0 mm. A smaller diameter of second segment 2918 may make it easier to insert guidewire 2900 and initiate a trajectory relative to the interior of the bone. First segment 2914 and second segment 2918 may be separated by third segment 2916. Third segment 2916 may be tapered such that the diameter of third segment 2916 transitions from D2 to D3.

[0064] The lengths of the first segment 2914, the second segment 2916, and the third segment 2918 can vary. The taper of the third segment 2916 can be from about 2° to about 5°, or greater than 5°. The second segment 2918 can have a length between about 14 mm and about 30 mm, between about 16 mm and about 28 mm, or between about 20 mm and about 25 mm. As shown in FIG. 29D, the first segment 2914 can be shorter and the third segment 2916 can be longer than the guidewire 2900 shown in FIGS. 29A-29C. As shown in FIG. 29E, the first segment 2914 can be shorter and the second and third segments 2916, 2918 can be longer. 30A-30F, guidewire 3000 can have a longer first segment 3014 and a shorter third segment 3016 compared to guidewire 2900 shown in FIGS. 29A-29C. Third segment 3016 of second portion 3008 of guidewire 3000 can have one or more (e.g., two) cutting grooves 3020. As the outer diameter of second portion 3008 increases from D3 to D2, cutting grooves 3020 can facilitate insertion of second portion 3008 of guidewire 3000 into the bone.

[0065] The guidewire 400 may be inserted into the bone during a fracture fixation procedure via the leading end 402, which may include a sharpened tip 412. Once the second portion 408 of the guidewire 400 has extended through the bone, the length of the second portion embedded within the bone may be measured directly or indirectly to determine the length of the implant 100 to be used so that the implant 100 does not protrude from the outer surface of the bone at either end of the implant 100.

[0066] The first portion 406 can have a length that exceeds the length of the implant 100 to slidably receive the implant 100 and more easily manipulate the rear end 404 of the guidewire 400 and / or facilitate interfacing of a driver with the driver interface 118 at the rear end 104 of the implant 100. The length of the first portion 406 can be, for example, between about 15 mm and about 60 mm, between about 18 mm and about 60 mm, between about 20 mm and about 60 mm, between about 25 mm and about 60 mm, between about 30 mm and about 60 mm, between about 35 mm and about 55 mm, or between about 40 mm and about 45 mm. The second portion 408 can have a length that is greater than sufficient to extend between opposite sides of the outer surface of the cortical wall. The length of the second portion 408 can be sufficient to more easily adjust the required length of the implant as the second portion 408 is inserted into the bone. The length of second portion 408 can be, for example, between about 30 mm and about 70 mm, between about 40 mm and about 65 mm, or between about 50 mm and about 60 mm.

[0067] The required or desired length of the implant 100 can be determined using a sizing tool, which can directly or indirectly measure the desired length of the implant 100. One example of a sizing tool is a depth gauge 500, as shown in FIGS. 5A-5D. The depth gauge 500 can be made of, for example, stainless steel, a biocompatible plastic, or any other suitable material. The depth gauge 500 can optionally be disposable. Disposable depth gauges do not need to be sterilized for reuse. Sterilization processes, such as by autoclave, can distort the shape of the depth gauge 500, thereby rendering it inaccurate.

[0068] The depth gauge 500 can include a distal portion 502 and a graduated portion 504. As shown in FIG. 5, the distal portion 502 can have a smaller dimension than the graduated portion 504, in one aspect. For example, the graduated portion 504 can gradually taper toward the distal portion 502. As shown in FIGS. 5B and 5C, the depth gauge 500 can have a generally uniform thickness, which can be in the millimeter range, for example. The length of the depth gauge 500 or a portion of the depth gauge 500, for example, the distance of the depth gauge 500 from the free end of the distal portion 502 to the first graduation mark 506, can vary according to the length of the second portion 408 and / or the overall length of the guidewire 400.

[0069] As will be described in more detail below, in use, the free end of the tip portion 502 can be positioned flush with the insertion point of the guide wire 400 on the outer surface of the bone. The depth gauge 500 can include an elongated slot 508 as part of the depth gauge 500, extending generally along the longitudinal axis CL of the depth gauge 500. As shown in FIGS. 5A and 5D , the slot 508 can terminate past a final graduation mark 510 near the free end of the graduation portion. The remainder of the guide wire 400 outside the insertion point in the bone can be aligned generally along the slot 508. A graduation mark (e.g., a number such as 48, 46, 44, etc., a letter, an icon, and / or the like) aligned with the beginning of the transition portion 410 can indicate the desired length (e.g., in mm) of the implant 100. As shown in FIG. 5A , instructions on how to read the measurements can be provided on the surface of the depth gauge 500 to reduce confusion regarding how to properly use the depth gauge 500.

[0070] 28A and 28B, the depth gauge 500 can include a bifurcated tip 503. The bifurcated tip 503 can improve engagement of the depth gauge 500 with any of the various examples of guidewires disclosed herein by reducing sliding of the tip of the depth gauge 500 against the guidewire, thus improving the ease of determining depth. The shape of the bifurcations can range from a general V-shape (e.g., FIG. 28A) to an arc or semicircle (e.g., FIG. 28D), but is not intended to be limited by the various examples shown in FIGS. 28A-28D.

[0071] 27A and 28B, guidewire 400 (or any other guidewire example disclosed herein) can include markings 426 to facilitate reading the depth using a sizing tool such as depth gauge 500. Markings 426 can be laser marks, colored bands, or any other suitable markings.

[0072] Additionally or alternatively, various other types of depth gauges may be used. For example, a depth gauge similar to depth gauge 500 may measure the distance of guidewire 400 from its insertion point into the bone to its trailing end 404. Such a depth gauge may have a longer overall length than depth gauge 500 shown in FIGS. 5A-5D . Alternatively, guidewire 400 itself may include depth markings, thereby eliminating the need for a separate sizing tool. In some configurations, such depth markings on the guidewire may be located closest to the insertion point in the bone and indicate the desired length of implant 100. In some implementations, the depth markings on the portion of the guidewire implanted in the bone may be radiopaque so as to be visible under fluoroscopy.

[0073] 6A-6D illustrate an example driver 600 configured to deliver the implant 100. The driver 600 may include a driver handle 602 and a driver shaft 604. The driver handle 602 and / or the driver shaft 604 may be formed of a suitable material, such as stainless steel, a biocompatible plastic, or other material. The driver shaft 604 may be coupled to the handle 602 using any suitable method, such as one or more dowel pins 606 as shown in FIGS. 6A and 6B, overmolding, or other methods.

[0074] 6C and 6D show a head portion 608 of the driver shaft 604. The head portion 608 is configured to interface with the driver interface 118 of the implant 100. In the illustrated example, the head portion 608 can have a hexagonal head that matches the hexagonal head interface of the implant 100. The head portion 608 can have other configurations depending on the type of driver interface of the implant.

[0075] As shown in FIG. 6D , at least the head portion 608 of the driver shaft 604 can be cannulated. In some configurations, the driver 600 can be cannulated (tubular) along its entire length or substantially its entire length. The diameter of the cannulation 610 can be configured such that, during an implant delivery procedure, the cannulation 610 can slidably receive the first portion 406 of the guidewire 400 and interface with the implant 100, which also slidably receives the first portion 406 of the guidewire 400. The diameter of the cannulation 610 can be the same as or substantially similar to the diameter of the through cannulation 120 of the implant 100, for example.

[0076] Exemplary Delivery Methods of the Intramedullary Fixation Systems Disclosed Herein Specific steps of a preferred exemplary method for delivering implant 100, 700 (or various variations of such methods in accordance with the present disclosure) are shown in Figures 8A-8F. However, the various methods described below can be used with any of the various guidewire embodiments disclosed herein. The methods are illustrated with reference to implant 100. However, any of the various variations of the implants disclosed herein, such as implants 2600C, 2600D, 2600E, and 2600F, can be inserted using the methods disclosed herein.

[0077] As shown in FIG. 8A, a human anatomical structure, including a damaged bone, is visualized using an imaging system, which may be fluoroscopy, e.g., using a C-arm or other imaging system. As shown in the X-ray image in FIG. 8A, a bone 6, which may be a phalanx, is fractured at a fracture site 22. As shown in FIG. 8B, a first guidewire 400 having at least two diameters may be inserted into the medullary canal of the bone 6 from its leading end 402. A second portion 408 of the guidewire 400 may be partially inserted into the bone. The guidewire 400 may be inserted percutaneously, i.e., through the skin, into the non-articular base of the bone (or the non-articular surface near the base). The guidewire 400 may be inserted, for example, from a proximal to distal direction. After entering the bone 6, the guidewire 400 may cross medially and laterally (or laterally and medially) relative to the bone and cross the fracture site 22.

[0078] 8C, the progression of guidewire 400 can be stopped when leading end 402 of guidewire 400 is flush, substantially flush, or just out of reach of outer surface 20 of bone 6 on the opposite side of medullary canal 9 from insertion point 24. The position of leading end 402 of guidewire 400 in bone 6 can be confirmed using an imaging system. The length of second portion 408 of guidewire 400 in bone 6 can be measured using any suitable sizing marks, sizing tool, or otherwise.

[0079] For example, a small incision (e.g., about 2 mm or other) can be made on the skin above the bone 6. The distal end 502 of the depth gauge 500 can be inserted into the small incision. In the example shown in FIG. 8C , the free end of the distal end 502 of the depth gauge 500 can be positioned flush over the insertion point 24 for the guide wire 400 in the bone 6. The guide wire 400 and / or the depth gauge 500 can be adjusted so that the guide wire 400 is visible in and runs substantially parallel to the elongated slot 508. A graduation mark aligned with the transition portion 410 of the guide wire 400 indicates the desired length of the implant, so that the implant 100, when implanted, can engage both cortical walls of the bone 6 while not protruding beyond the outer surface of the bone at either end of the implant 100. As shown in FIG. 8C , the transition portion 410 can be aligned with the 45 mm graduation mark. An implant having a length of approximately 45 mm or the next nearest available length not exceeding 45 mm (such as 44 mm) may be selected. After sizing the implant 100, the depth gauge 500 may be removed.

[0080] 8D , the guidewire 400 may be further advanced through the bone 6 until the transition portion 410 substantially reaches the bone insertion point 24. A first cannulated implant 100 having a desired length, for example, between about 44 mm and about 45 mm in the illustrated example, may be slid over the first portion 406 of the guidewire 400. The first implant 100 may cease its advancement over the first portion 406 of the guidewire 400 upon reaching the transition portion 410. An at least partially cannulated driver 600 may also be slid over the trailing end 404 of the guidewire 400 relative to the remainder of the first portion 406 of the guidewire 400.

[0081] The driver 600 can be advanced along the first portion 406 of the guidewire 400 until the driver head portion 608 of the driver 600 engages the driver interface of the implant 100 at the trailing end 104 of the implant 100. Alternatively, the implant 100 and driver 600 can be removably connected before being advanced over the guidewire 400. Using the driver 600, the implant 100 can be delivered through a tunnel in the bone formed by the second portion 408 of the first guidewire 400. The root or minor diameter of the shaft 106 of the implant 100 can be substantially the same as the outer diameter D2 (see FIG. 4B ) of the second portion 408 of the guidewire 400. The second portion 408 of the guidewire 400 can thus provide passage for the root or minor diameter of the shaft 106 of the implant 100. Alternatively, outer diameter D2 can be substantially the same as the outer or maximum diameter D of implant shaft 106 (see FIG. 3A ). Due to the at least two diameters D1, D2 (see FIG. 4B ) of guidewire 400, implant 100 can have a greater wall thickness, and therefore greater structural rigidity, along the length of implant 100, while maintaining outer diameter D to be smaller, only slightly greater than D2 of second portion 408 of guidewire 400. The at least two diameters of guidewire 400 allow a bone tunnel formed using second portion 408 of guidewire 400 to require less torque to drive implant 100 into bone 6, and / or insertion of implant 100 causes less or no additional trauma to bone 6 compared to insertion of guidewire 400. If greater resistance is felt in inserting the implant 100, the driver 600 may be retracted a few turns (eg, about 2 turns) before resuming insertion of the implant 100.

[0082] The placement of the implant may be intermittently (or continuously) confirmed via an imaging system. The thread pitch of the implant 100 may be configured to allow for more finely adjustable and precise control of the advancement distance of the implant 100 in the bone 6 by rotating the driver 600 compared to advancing a standard K-wire into the bone by axial advancement of the K-wire driver. The greater control provided by the driver 600 may further allow for more precise placement of the implant 100 in the bone 6 and further reduce the likelihood of the leading end 102 or trailing end 104 of the implant 100 penetrating into the tissue surrounding the bone 6.

[0083] 8E , after the first implant 100 is implanted at a desired location within the bone 6, the first guidewire 400 may be removed from the first implant 100 and from the bone 6. For example, the first portion 406 of the first guidewire 400 may be removed distally. Because D1 of the first portion 406 of the guidewire 400 is less than D2 of the second portion 408 of the guidewire 400, pulling the first portion 406 of the guidewire 400 out of the bone 6 does not cause additional damage to the bone 6.

[0084] The same steps can be repeated with the same guidewire 400 or a second guidewire 400 to deliver a second implant 100. The second implant 100 may or may not have the same length as the first implant. As shown in FIG. 8E , the same second guidewire 400 or a second portion 408 of the second guidewire 400 can be inserted into a different insertion point 26 at the non-articular base of the bone 6 at an angle such that the guidewire 400 can cross the first implant 100 and the leading end 402 of the guidewire 400 can terminate in the cortical wall opposite the cortical wall engaged by the leading end 102 of the first implant 100.

[0085] Ensure that the guidewire 400 and the first implant 100 are separated by a minimum distance to ensure that the threads on the second implant 100 do not contact the outer surface of the first implant 100 when the second implant 100 is implanted over the guidewire 400 as shown in FIG. 8E, as such contact during insertion of the second implant 100 may transmit higher torque values ​​to the driver 600, which may result in failure of the driver 600.

[0086] After the second implant 100 has been implanted into the bone 6 to the desired position, the same guidewire 400 or the second guidewire 400 can be removed from the second implant 100 and the bone 6 as described above. FIGS. 8F and 8G show X-ray images of the implanted, crossed and secured first and second implants 100. FIG. 8F shows the generally x-shaped configuration of the two implants. Neither end of either implant 100 protrudes beyond the outer surface 20 of the bone 6 to avoid interaction with the tissue surrounding the bone 6. The first and second implants 100 are crossed to improve rotational control of the fractured portions of the bone.

[0087] The delivery method of the cannulated implant 100 using a guidewire 400 having at least two diameters can also benefit from employing some of the same techniques as the standard K-wire crossing and fixation described above. Because surgeons have likely already been trained and are familiar with the crossing and fixation techniques, they can more safely and efficiently implement the systems and methods disclosed herein. However, the fixation systems and methods disclosed herein further improve upon standard K-wire crossing and fixation by, for example, providing more accurate sizing of these implants, reducing postoperative implant displacement, and providing other benefits disclosed herein.

[0088] The two implants 100 may be implanted using different delivery methods as shown in Figures 9A-9H. The alternative methods may include any of the associated steps described above, such as imaging the bone, implant 100, and / or delivery device including guidewire 400, inserting guidewire 400, sizing implant 100, and / or inserting the first and second implants 100 using guidewire 400. Features described in Figures 9A-9H may be incorporated into the methods described above.

[0089] As shown in FIG. 9A , another implantation procedure may include inserting a first guidewire 400 having at least two diameters and a second guidewire 400 having at least two diameters in a cross-sectional pattern prior to inserting either implant 100. A predetermined distance between the second portion 408 of the first guidewire 400 and the second portion 408 of the second guidewire 400 may be confirmed using an imaging system to reduce the possibility of the two implants 100 contacting each other during insertion. As shown in FIG. 9B , the two second portions 408 of the two guidewires 400 may be withdrawn from the bone 6, leaving the two first portions 406 of the two guidewires 400 in the bone in the tunnels formed by the insertion of the two second portions 408.

[0090] As shown in FIG. 9C , the first implant 100 may be inserted by the driver 600, guided by the first portion 406 of the guide wire 400, into the bone tunnel formed by the second portion 408 of the guide wire 400. As shown in FIG. 9D , after the first implant 100 has been delivered to the desired location, the driver 600 may be removed. The steps of FIGS. 9E and 9F, 9C and 9D are repeated to show the insertion of the second implant 100, guided by the second guide wire 400. Once both implants 100 have been delivered to their desired locations, the first and second guide wires 400 and 400 may be removed from the first and second implants 100 and from the bone 6.

[0091] 9A, the first and second guidewires 400, 400 may be advanced further into the bone until the transition portions 410 of the guidewires 400 are adjacent to the insertion points in the bone, similar to the step shown in FIG. 8D for a single guidewire 400. The first and second implants 100 may then be inserted into the bone along with the first portions 406 of the first and second guidewires 400, 400, as described above.

[0092] Alternatively, as shown in FIG. 10 , a first implant 100 and a second implant 100 can be inserted substantially parallel to each other into a bone 16 having a fracture 22. Neither end of the first implant 100 nor the second implant 100 protrudes beyond the outer surface 20 of the bone 6. The first implant 100 and the second implant 100 may or may not have the same length. This method can incorporate steps from any of the various methods described above. For example, the first implant 100 and the second implant 100 can be inserted using one or more guidewires, such as the guidewire 400 disclosed herein. If separate guidewires are used for each implant 100, both guidewires can be inserted substantially parallel to each other into the bone 6 before the insertion of the first implant 100 and the second implant 100 guided by the guidewires. Alternatively, the second guidewire can be inserted after the insertion of the first implant 100 guided by the first guidewire. The first guide wire may be removed or may remain inside the bone 6. The second guide wire may be inserted substantially parallel to the implanted first implant 100. Alternatively, two or more implants 100 may be inserted into the patient's bone, arbitrarily positioned relative to one another, using the methods disclosed herein.

[0093] Lag screw using the surgical device disclosed herein The surgical device described above may be used to deliver a number of different types of implants, such as, but not limited to, lag screws, instead of or in addition to the techniques described above. One or more lag screws and lag techniques can compress fractured bone fragments together to achieve fixation and promote healing at the fracture site. Lag screws can be used for various types of fractures, including, but not limited to, avulsion fracture fixation, mallet fracture fixation, distal uni / biconvex fracture fixation, spiral / oblique fixation, Roland fracture fixation, and Bennett fracture fixation. Lag screws can be used to fix a number of different types of bones, such as the phalanges shown in FIGS. 11A and 11B and the metacarpals shown in FIG. 11C. The following method is described using guidewire 400 as an example. However, the method described below can be used with any of the guidewire embodiments described herein.

[0094] Conventional lag screw implantation techniques may involve pre-drilling holes through the proximal and distal cortices of the bone using a reamer. When the screw is tightened, the threads at the end of the screw engage the distal cortex and the head of the screw engages the proximal cortex, compressing the fractured fragments together. In addition to the need for a specialized reamer to create the bone tunnel, conventional lag screw implantation techniques can have several other challenges. As shown in FIG. 12A, when inserting a (non-cannulated) lag screw through a bone tunnel created by a bone reamer, it can be difficult for the surgeon to find the distal cortex with the tip of the lag screw. As shown in FIG. 12B, if the lag screw is threaded throughout substantially the entire shaft, a glide hole is required. The step of creating a glide hole is also known as overdrilling. As shown in FIG. 12B, the proximal cortex is overdrilled using a first reamer to the maximum outer diameter of the lag screw shaft to form a glide hole, and then the distal cortex is drilled using a second, smaller-sized reamer to a diameter similar to the minor diameter of the screw shaft. When the screw is inserted, it slides through the glide hole and only engages the distal cortex through the screw hole. Overdrilling is an additional drilling step that can complicate the implantation procedure. This additional step can also increase the risk of iatrogenic damage or injury. As shown in FIG. 12C, when a cannulated lag screw is used, a conventional K-wire is first inserted through the proximal and distal cortices before the reamer is introduced. However, the K-wire may pull out or slip out in the direction indicated by the arrow during the procedure (e.g., when the first reamer for overdrilling is removed) and need to be strengthened, which can complicate the procedure. Furthermore, as shown in FIG. 12D, due to the small outer diameter of conventional K-wires as described above, the K-wires may bend during insertion into the bone, making them difficult to use for introducing cannulated lag screws.

[0095] The surgical instruments disclosed herein, particularly the guidewire 400 of FIGS. 4A-4C for delivering a lag screw, can address some of the problems discussed above and others. As shown in FIG. 13 , an exemplary lag screw 1300 can be delivered using the guidewire 400. The lag screw 1300 can be formed from stainless steel, titanium, hard plastic, or the like. The lag screw 1300 can include a head 1302 and a shaft 1304. The head 1302 can be a hex drive head, or the like. The shaft 1304 can have a minor diameter D1. The shaft 1304 can be threaded at its terminal portion 1306. In some embodiments, the shaft 1304 can be fully threaded. The terminal portion 1306 can have a maximum diameter D2. The lag screw 1300 can be cannulated to allow it to slide over the first portion 406 of the guidewire 400. The outer diameter of the first portion 406 of the guidewire 400 can be, for example, about 0.6 mm, or other values ​​disclosed herein. The minor diameter D1 of the shaft 1304 of the lag screw 1300 can be substantially the same as the outer diameter of the second portion 408 of the guidewire 400. As described below with reference to FIGS. 14A-14E , the passage of the minor diameter D1 of the shaft 1304 of the lag screw 1300 can be prepared by the second (larger diameter) portion 408 of the guidewire 400. The outer diameter D1 and / or the second portion 408 of the screw 1300 can be, for example, about 1.1 mm. The threaded outer diameter of the screw 1300 can be greater than 1.1 mm, for example, about 1.5 mm. The length of the screw 1300 can be between about 6 mm and about 22 mm, between about 7 mm and about 21 mm, between about 8 mm and about 20 mm, between about 9 mm and about 19 mm, or between about 10 mm and about 18 mm, etc.

[0096] Specific steps of an exemplary method for delivering the lag screw 1300 (or other lag screws) are shown in FIGS. 14A-14E . This method does not involve the use of a cannulated drill as in conventional cannulated lag screw implantation procedures. While pre-drilling is not required before introducing the guide wire 400 into the bone 6, most conventional cannulated screw systems require the use of a guide wire and a separate cannulated drill. While some systems can eliminate the cannulated drill step by using cutting features at the tip of the screw to make the screw self-drilling or self-tapping, these systems are still limited to K-wires with very small diameters for initial targeting. Because the cannulated screw slides over and is guided by the K-wire during insertion into the bone, the outer diameter of such a K-wire is limited by the size of the screw cannulation. Also, as mentioned above, K-wires with small diameters may bend or bend during insertion into the bone and therefore may be difficult to use for initial targeting. In comparison, guidewire 400 includes second portion 408 with a larger outer diameter at tip 402 (to provide a path for the screw). The outer diameter of second portion 408 is larger than the size of the screw cannulation. Second portion 408 is stiffer and less prone to bending, making it easier to insert into bone than a conventional K-wire. Furthermore, a screw can be inserted into bone by sliding it over first portion 406 of guidewire 400, which has a smaller outer diameter.

[0097] As shown, a bone 6, such as a phalange, is fractured at fracture site 22. A guidewire 400 may be inserted into bone 6 from its leading end 402. Insertion of the guidewire 400 may be assisted by a suitable guidewire driver 1400. The guidewire driver 1400 shown in FIGS. 14A, 14C, and 14D is for illustrative purposes only and not limiting. The guidewire driver 1400 may include a handle 1402 for the user's hand to facilitate pushing and / or pulling the guidewire 400. The guidewire driver 1400 may include a collet or collet system for gripping the second portion 408 of the guidewire 400. The guidewire driver 1400 may not need to have a dedicated collet or collet system for gripping the thinner first portion 406 of the guidewire 400. The thinner first portion 406 may be too small to engage a commercially available collet.

[0098] As shown in FIG. 14B , the second portion 408 of the guidewire 400 can be partially inserted into the bone 6 to the desired final implantation depth and can penetrate at least the proximal cortex 24 of the bone 6. As shown in FIG. 14B , the leading end 402 of the guidewire 400 is just about to penetrate the surface of the bone at the distal cortex 26. The position of the leading end 402 of the guidewire 400 in the bone 6 can be confirmed using an imaging system. The guidewire driver 1400 can be temporarily removed from the guidewire 400, and the depth gauge 500 described above with reference to FIG. 8C can be used to determine the desired length or size of the lag screw. After determining the size of the lag screw, the depth gauge 500 can be removed. The length of the second portion 408 of the guidewire 400 in the bone 6 can be measured using appropriate sizing marks, tools, or other means. As shown in FIG. 14C, guidewire driver 1400 can re-engage guidewire 400 and continue to advance leading end 402 of guidewire 400 in the direction of the arrow through distal cortex 26 of the bone.

[0099] 14D , the guidewire driver 1400 can be disengaged from the second portion 408 of the guidewire 400 at the side of the proximal cortex 24 and re-engaged with the second portion 408 of the guidewire 400 at the side of the distal cortex 26 of the bone 6. The guidewire driver 1400 can be pulled on the guidewire 400 and away from the bone 6 to pull the first portion 406 of the guidewire 400 toward the proximal cortex 24 of the bone 6.

[0100] As shown in FIG. 14E , the guidewire driver 1400 may be withdrawn from the bone 6 to pull the guidewire 400 until the first portion 406 of the guidewire 400 enters the bone 6 from the proximal cortex 24. The guidewire driver 1400 may be removed from the guidewire 400. A lag screw 1300 having a desired length determined using a depth gauge or other means may be slid over the first portion 406 of the guidewire 400. The at least partially cannulated driver 600 described above may be slid over the remainder of the first portion 406 of the guidewire 400 via the trailing end 404. The driver 600 may be advanced along the first portion 406 of the guidewire 400 until the driver head portion 608 of the driver 600 engages the driver interface of the lag screw 1300 in the head 1300 of the lag screw 1300. Alternatively, the lag screw 1300 and driver 600 may be removably connected before being advanced over the first portion 406 of the guidewire 400. As described above, the minor diameter of the shaft 1304 of the lag screw 1300 may be substantially the same as the outer diameter of the second portion 408 of the guidewire 400. Using the driver 600, the lag screw 1300 may be advanced through a tunnel in the bone formed by the second portion 408 of the first guidewire 400. The threaded terminal end 1306 of the screw 1300 may engage the distal cortex 26 and the head 1302 of the screw 1300 may engage the proximal cortex 24, compressing the fractured fragments together. Screw placement may be intermittently (or continuously) confirmed using an imaging system. Alternatively, the screw 1330 may be advanced into the bone 6 using a driver different from the driver 600 in FIG. 14E .

[0101] For example, as shown in FIGS. 14A-14E, using an instrument including at least a guidewire 400 to deliver the lag screw 1300 can eliminate a pre-drilling step, the need for a separate reamer (or drill), and / or the need for a special collet for the K-wire driver to engage a conventional K-wire with a small outer diameter (e.g., less than about 0.7 mm). The delivery method shown in FIGS. 14A-14E can eliminate K-wire withdrawal, particularly after over-drilling when switching to a different size reamer, and can maintain bone reduction by holding the guidewire 400 in place while advancing the screw 1300. Furthermore, the larger-diameter second portion 408 of the guidewire 400 can be stiffer, less flexible, and easier to insert into the bone 6 than a conventional K-wire with a smaller outer diameter.

[0102] Eliminating the need for reamers or drills, which are typically reusable and sterilized after each use, allows the surgical instruments and / or screws or other implants disclosed herein to be packaged in a sterile (and optionally disposable or single-use) kit. As shown in FIG. 15 , packaged kit 1500 can include a sterile surgical instrument package 1502 and a sterile implant package 1504. Sterile surgical instrument package 1502 can include guidewire 400, driver 600, and depth gauge 500. Guidewire 400, driver 600, and / or depth gauge 500 can be single-use or reusable. In order to reuse guidewire 400, driver 600, and / or depth gauge 500, these instruments can be resterilized after each use.

[0103] Stepped or dual-diameter guidewires, such as the guidewire 400 of FIGS. 4A-4C or the guidewire examples of FIGS. 29A-32B, can provide flexibility in surgical technique depending on the user's (e.g., surgeon's) preferences. For example, in a Jones fracture fixation or another fracture fixation procedure, a user may prefer a cannulated technique but a solid screw to increase implant strength. Having a stepped guidewire with a connected smaller-diameter trailing end that allows for the insertion of a cannulated device and a larger-diameter leading end that prepares the path for the implant allows for both solid and cannulated techniques. For solid techniques, the solid screw can include a small recess and / or be partially cannulated at the leading end for interaction with the thinner portion of the dual-diameter guidewire disclosed herein. Furthermore, a stepped guidewire may provide the ability to insert a cannulated screw with a larger wall thickness (cannulation with a smaller diameter) with strength closer to that of a solid screw than a cannulated screw with a larger cannulation diameter.

[0104] The lag screw 1300 disclosed herein may be used in other applications. For example, as shown in FIG. 16 , multiple lag screws 1330 may be delivered using a tool disclosed herein, such as a guidewire 400, and such multiple lag screws 1330 may be used in combination with an intramedullary nail for fracture fixation. The intramedullary nail 1400 may be threaded and may include a first section having a first maximum diameter and a second section having a second maximum diameter. There may be a transition portion between the first and second sections. The transition portion may have a maximum diameter that changes from the first maximum diameter to the second maximum diameter. Further details of the intramedullary nail 1600 are described in International Publication No. WO 2019 / 050833, published March 14, 2019, which is incorporated herein by reference in its entirety. The combination of one or more lag screws 1300 and the intramedullary nail 1400 may be used for fixation of more complex fractures. As shown in Figures 17A and 17B, the instruments and delivery methods disclosed herein can deliver lag screws for fracture fixation not only in the hand as shown above, but also in the metatarsals (Figure 17A) and phalanges (Figure 17B) of the foot.

[0105] Exemplary Alternative Delivery Tools to Stepped Guidewires Alternatives to the stepped guidewires in FIGS. 4A-4C and 29A-32B and methods using the guidewires disclosed herein, additional tools and methods for introducing cannulated implants (e.g., cannulated implants 100, 2600, 2600C, 2600D, 2600E, 2600F, lag screw 1300, intramedullary needles described in WO 2019 / 050833 or others), partially cannulated implants, or non-cannulated implants, are described with reference to FIGS. 18-25B. The alternatives described below are not intended to be limiting. Features of any of the various examples described below may be combined or incorporated with features of another of these features.

[0106] The stepped guidewires in FIGS. 4A-4C and 29A-32B, and alternative examples thereof described below with reference to FIGS. 18-25B, can be used to deliver any threaded (any helical thread regardless of pitch size) or partially threaded implant, such as the exemplary orthopedic implant 100 and lag screw 1300 disclosed herein, and / or any other elongated implant that does not necessarily include threads but may include one or more protrusions on the implant shaft. If the implant is fully or partially threaded, such threads can have any pitch size. The one or more protrusions can include one or more barbs, one or more fins, one or more ridges, and / or the like. The one or more protrusions can have any shape or size. The partially or fully threaded implants can be inserted into the bone by rotation. The unthreaded implants can be inserted into the bone by impaction.

[0107] 18A and 18B illustrate steps for delivering a cannulated implant using a cannulated drill 1800. All of the drills shown in FIGS. 18-25B can include a guide wire having a larger outer diameter than a conventional K-wire (e.g., substantially similar to the small diameter for the shaft of an implant used for fracture fixation). As shown in FIG. 18A, in a first step, the cannulated drill 1800 can be inserted into the bone 6 across the fracture line 22 in the direction indicated by arrow 1. Insertion of the cannulated drill 1800 can provide a pathway for the implant in the bone 6. As shown in FIG. 18B, in a second step, a K-wire 1810 having a smaller outer diameter can be inserted into the cannulation of the cannulated drill 1800 in the direction indicated by arrow 2. In a third step, the cannulated drill 1800 can be removed along the direction indicated by arrow 3, with the K-wire 1810 remaining in the implant path to maintain fracture reduction and provide guidance for implanting the cannulated implant above the K-wire 1810.

[0108] 19 shows a drill or guidewire 1900 including a wire loop 1902 attached to a rear end 1904 of the drill 1900 (opposite the tip of the drill, which may include a trocar or any other sharp tip). The drill 1900 may be non-cannulated, or substantially non-cannulated. The drill 1900 may be inserted into the bone 6 across the fracture line 22 to provide a pathway for an implant in the bone 6. A corresponding K-wire having a smaller outer diameter than the drill 1900 may include a hook 1912. The hook 1912 engages the wire loop 1902 such that when the drill 1900 is pulled through the pathway for an implant distal to the bone 6, the K-wire 1910, following the drill 1900, may be pulled through the pathway for an implant into the bone 6. After the drill 1900 is removed, the K-wire 1910 can remain in the implant path to maintain fracture reduction and provide guidance for implanting a cannulated implant over the K-wire 1910. By disengaging the hook 1912 from the wire loop 1902, the drill 1900 can be disengaged from the K-wire 1910. The configuration shown in FIG. 19 can be reversed so that the hook is on the trailing end 1904 of the drill 1900 and the loop is on the K-wire 1910. Optionally, the connection point between the hook and loop can be crimped to reduce the likelihood of separation between the hook and loop as the drill 1900 is drawn through the bone.

[0109] 20 , a guidewire 400 similar or substantially identical to the guidewire 400 described above may be used to deliver an implant 2000 that includes a blind hole 2002 (rather than a through cannulation) at its leading end 2004. In other words, the implant 2000 may have any of the features of the implant 100 or lag screw 1300, except that the implant 2000 is not fully cannulated. The blind hole 2002 may be sized to slidably receive the thinner first portion 406 of the guidewire 400. The implant 2000 may engage the thinner first portion 406 of the guidewire 400 after the thicker second portion 408 has been inserted into the bone or bone fragment to prepare the bone or bone fragment for the implant. After the implant 2000 engages the guide wire 400 in the blind hole 2002, the driver 600 disclosed herein or any other suitable driver (e.g., a non-tubular driver) can be used to insert the implant 2000 into the bone for fixation of the fracture.

[0110] The thicker second section and thinner first section of the guidewire disclosed herein can be removably connected to deliver a cannulated implant during fracture fixation. FIGS. 21A and 21B show a partially cannulated drill 2100 including a blind hole 2102 at its trailing end 2104. The outer diameter of the drill 2100 can be substantially the same as the outer diameter of the second section 408 of the guidewire 400 described above. The blind hole 2102 can accept a K-wire 2110 having a smaller diameter (e.g., any conventional commercially available K-wire having an outer diameter of less than about 0.7 mm). When the drill 2100 is inserted into the bone to prepare the implant passage, the K-wire 2110 can be pulled through the implant passage distal to the bone. After the drill 2100 is pulled through the bone, the K-wire 2110 can remain in the implant path to maintain fracture reduction and provide guidance for implanting an implant (screw, nail, or other) cannulated over the K-wire 2110. As shown in FIG. 21B , to improve the strength of the connection between the blind hole 2102 of the drill 2100 and the K-wire 2110, a needle driver 2120 or any other suitable tool can optionally crimp the drill 2100 and K-wire 2110 together at the blind hole 2102 before pulling the drill 2100 through the bone.

[0111] As shown in FIG. 22A , instead of a blind hole, the drill 2200 can include a female recess 2202 at its rear end 2204. The implant 2230 (screw, nail, or other) can have a mating male portion 2232 at its front end to engage within the female recess 2202. The implant 2230 does not have to be cannulated. The outer diameter of the drill 2200 can be substantially the same as the minor or minor diameter of the implant 2230. When the drill 2200 is pulled through the implant channel at the distal side of the bone, the male portion 2232 remains engaged within the female recess 2202 so that the implant 2230 can be pushed along with the drill 2200, for example, using the driver 600 or any other driver. After the drill 2100 is pulled through the bone, the implant 2230 can remain in the implant channel to maintain fracture reduction and provide fixation of the fractured bone. 22B, the female recess 2202 may be internally threaded and the mating male portion 2232 may include corresponding external threads to improve the bond strength between the implant 2230 and the drill 2200 when the implant 2230 is inserted into the bone or bone fragment along with the drill 2200. After implantation of the implant 2230, the drill 2200 may be unscrewed and removed from the implant 2230.

[0112] 22A and 22B, the head of the implant 2230 can instead be manufactured with a break-away or snap-off connection 2234 that can be inserted with a wire driver 601, as shown in FIG. 22C. The snap-off feature 2234 can be disengaged from the wire driver 601 with a certain torque or by bending the wire driver 601 back and forth. The wire driver 601 can be disengaged from the implant 2230 after the implant 2230 has been inserted into the desired location in the bone or bone fragment using the drill 2200.

[0113] 22A and 22B to deliver the implant 2300, the hex driver 2300 can optionally include an Association for Osteosynthesis (AO) feature 2334 and / or a wire driver portion having a smaller diameter at its trailing end (opposite the hex or hex socket driver interface end 2332). The AO feature 2334 can allow for powered insertion using a wire driver 2336 with an AO quick connect feature or another power source. Alternatively, the driver 2300 can be used by hand without power.

[0114] As shown in FIG. 24 , a solid guidewire 2410 having a larger outer diameter (e.g., about 1.0 mm) than a conventional K-wire can be used as an alternative to using a stepped guidewire. One approach to using a slightly larger guidewire, which requires a larger cannulation diameter for the implant, is to increase the outer minor diameter (root diameter) of the implant to maintain the desired implant strength. However, if one wishes to maintain the overall outer shape of the implant (i.e., the same outer diameter), it is necessary to reduce the thread depth in the implant. To address the issue of reducing thread depth, as shown in FIG. 24 , the implant 2400 can eliminate threads along the middle section 2404 of the shaft 2402 (e.g., for about 80% of the shaft length). The outer diameter of the unthreaded middle section 2402 can be the same as the maximum diameter of the threaded portion of the implant shaft. The implant 2400 can function as a strong tube or strut while having threads 2406 at the anterior and posterior ends to provide bone attachment. Although implant 2400 may have a thinner wall thickness, implant 2400 can have similar strength to implant 100 due to the greater amount of material in the unthreaded middle portion 2404 compared to when the middle portion is threaded.

[0115] As shown in FIGS. 25A and 25B , a guidewire 2510 having a larger outer diameter than a conventional K-wire can be connected (e.g., rigidly connected) to a leading end 2522 of an implant 2520. The outer diameter of the guidewire 2510 can be substantially the same as the minor diameter of the implant 2520. The connection between the guidewire 2510 and the implant 2520 allows the guidewire 2510 and the implant 2520 to move axially as a single piece. The implant 2520 can be any of the example implants or screws disclosed herein or any other implant configured to be inserted into bone and / or bone fragments. The guidewire 2510 can be non-cannulated. The leading end 2512 of the guidewire 2510 can include a sharp tip. In use, the leading end 2512 of the guidewire 2510 can facilitate reaming a bone tunnel through the bone or bone fragment with the implant 2520 connected to the guidewire 2510. Once the implant 2520 has been inserted to the desired location, for example via radiographic confirmation, the guidewire 2510 can be severed at the leading end 2522 of the implant 2520. The interface between the leading end 2522 of the implant 2520 and the guidewire 2510 can include a thinned portion to facilitate severing of the guidewire 2520 at the thinned portion. Thus, the combination of the guidewire 2510 and implant 2520 can eliminate a preliminary drilling step and the need for a separate reamer (or drill) to insert the implant 2520 into the bone or bone fragment.

[0116] As shown in FIG. 25B , in addition to the leading guidewire 2510, a trailing guidewire 2530 can be connected (e.g., rigidly connected) to the trailing end 2524 of the implant 2520. The connection between the trailing guidewire 2530 and the implant 2520 allows axial forces applied to the trailing guidewire 2530 to be transmitted axially along the implant 2520 and the leading guidewire 2510. The guidewire 2530 can have a larger outer diameter than a conventional K-wire, for example, can have an outer diameter substantially the same as the minor diameter of the implant 2520. The trailing guidewire 2530 can function as a driver during insertion of the implant 2520 and leading guidewire 2510 into the bone or bone fragment. Once the implant 2520 is inserted to the desired location, the guidewire 2530 can be cut at the trailing end 2524 of the implant 2520. The interface between the trailing end 2524 of the implant 2520 and the trailing guidewire 2530 can include a narrowed portion, allowing the trailing guidewire 2530 to be easily severed at the narrowed portion. The addition of the trailing guidewire 2530 to the implant 2520 and leading guidewire 2510 combination can further eliminate the need for a separate driver. The implant 2520 and leading guidewire 2510 combination and / or the implant 2520, leading guidewire 2510, and trailing guidewire 2530 combination can be made available in a number of different sizes. Such a number of different sizes can accommodate a number of different outer diameters of the implant 2520.

[0117] term While the present disclosure has been described in the context of particular embodiments and examples, those skilled in the art will understand that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as obvious modifications and equivalents thereof. Additionally, while several variations of the disclosed embodiments have been shown and described in detail, other variations that are within the scope of the present disclosure will be readily apparent to those skilled in the art. It is also contemplated that various combinations or subcombinations of specific features and aspects of the embodiments may be made and still fall within the scope of the present disclosure. For example, features described above in connection with one embodiment may be used with different embodiments described herein, and such combinations will still fall within the scope of the present disclosure. It should be understood that various features and aspects of the disclosed embodiments may be combined with or substituted for one another to form various aspects of the disclosed embodiments. Thus, it is intended that the scope of the disclosure herein should not be limited by the specific embodiments described above. Thus, unless stated to the contrary or clearly incompatible, each embodiment of the present invention may comprise, in addition to its essential features described herein, one or more features as described herein from each other embodiment of the present invention described herein.

[0118] It should be understood that features, materials, characteristics, or groups described in connection with a particular aspect, embodiment, or example are applicable to other aspects, embodiments, or examples described in this section or elsewhere in this specification, except to the extent that such features, materials, or groups are incompatible. All features disclosed in this specification (including the accompanying claims, abstract, and drawings) and / or all steps of methods or processes so disclosed may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of the embodiments described above. Protection extends to any novel feature or novel combination of features disclosed in this specification (including the accompanying claims, abstract, and drawings), or to any novel step or novel combination of steps of methods or processes so disclosed.

[0119] Furthermore, certain features that are described in this disclosure in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple implementations separately or in any suitable subcombination. Furthermore, while features are described above as acting in certain combinations, in some cases, one or more features from the combination defined in the claims may be excluded from such combination, and such combination may be defined in the claims as a subcombination or as a variation of a subcombination.

[0120] Furthermore, while operations may be depicted in the figures or described in the specification in a particular order, such operations need not be performed in that particular order or sequential order shown, or even all operations need to be performed to achieve desired results. Other operations not shown or described may be incorporated into the example methods and processes. For example, one or more additional operations may be performed before, after, concurrently with, or between the operations described above. Furthermore, one or more additional operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be omitted and other steps may be added. Furthermore, features and attributes of the specific embodiments described above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. It should also be understood that the separation of various system components in the above-described implementations should not be understood as requiring such separation in all implementations, and that the described components and systems may generally be integrated together in a single product or packaged in multiple products.

[0121] For purposes of this disclosure, certain aspects, advantages, and novel features have been described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure may be embodied or carried out in a manner that achieves one or more advantages taught herein without necessarily achieving other advantages that may be taught or suggested herein.

[0122] Conditional language such as "can," "could," "might," or "may," unless otherwise specified or understood otherwise within the context in which it is used, is intended to generally convey that certain embodiments include certain features, elements, and / or steps that other embodiments do not include. Thus, such conditional language is not intended to generally imply that features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without user input or prompting, whether or not those features, elements, and / or steps are included or should be performed in any particular embodiment.

[0123] Unless otherwise specified, conjunctions such as "at least one of X, Y, and Z" are understood in context as commonly used to convey that a certain item, term, etc. can be either X, Y, or Z. Thus, such conjunctions are not generally intended to suggest that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z.

[0124] As used herein, words indicating degrees, such as "approximately," "about," "generally," and "substantially," express a value, amount, or characteristic that is close to a stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can mean an amount that is within 10%, within 5%, within 1%, within 0.1%, and within 0.01% of the stated amount.

[0125] The scope of the present disclosure is not intended to be limited by the specific disclosure of preferred embodiments in this or other sections herein, but rather may be defined by the claims presented or to be presented in the future in this or other sections herein, which claim language is to be interpreted broadly based on the language used in the claim language and not limited to the examples (which should be construed as non-exclusive) set forth herein or during the prosecution of this application.

Claims

1. A multi-diameter guidewire configured to deliver a cannulated orthopedic implant, comprising: a first portion having a first outer diameter D1; a second portion including a first segment, a second segment, and a third tapered segment, the first segment having a second outer diameter D2 greater than the first outer diameter D1, the second segment having a third outer diameter D3 less than the second outer diameter D2, and the third tapered segment extending between the first segment and the second segment; Equipped with the cannulated orthopedic implant is configured to be slidably mounted over the first portion of the guidewire; The guidewire, wherein the second outer diameter D2 is substantially the same as a minor or root diameter of the cannulated orthopedic implant.

2. A guide wire as described in claim 1, wherein the free end of the second segment of the second portion includes a sharp tip.

3. A guide wire as described in claim 1, wherein the third tapered segment has one or more cutting grooves.

4. A guide wire as described in claim 1, wherein the outer diameter of the third tapered segment transitions from D2 to D3.

5. A guide wire as described in claim 1, wherein the first segment is longer than the second segment and the third tapered segment.

6. A guide wire as described in claim 1, wherein the first portion has a uniform outer diameter D1.

7. A guide wire as described in claim 1, further comprising a transition portion between the first portion and the second portion.

8. A guide wire as described in claim 7, wherein the transition portion transitions from an outer diameter D1 to an outer diameter D2.

9. A cannulated first elongated implant having a first implant shaft outer diameter, a valley or minor diameter, and a first implant cannulation diameter; a multi-diameter guidewire configured to deliver the first elongated implant into a fractured bone by intramedullary fixation; a first portion having a first outer diameter D1; a second portion including a first segment, a second segment, and a third tapered segment, the first segment having a second outer diameter D2 greater than the first outer diameter D1, the second segment having a third outer diameter D3 less than the second outer diameter D2, and the third tapered segment extending between the first segment and the second segment; a guide wire comprising: Equipped with the first elongate implant is configured to be slidably mounted over the first portion of the guidewire; The kit for an intramedullary fracture system, wherein the second outer diameter D2 is substantially the same as a minor or root diameter of the first elongated implant.

10. A second elongated implant configured to be implanted together with the first elongated implant by intramedullary fixation, further comprising a cannulated second elongated implant having an outer diameter of the second implant shaft or a valley or minor diameter of the second implant, and a second implant cannulation diameter; the second outer diameter D2 of the guidewire is substantially the same as the outer diameter of the second implant shaft or the root or minor diameter of the second implant; The kit of claim 9 , wherein the second implant cannulation diameter is configured to accommodate the first portion of the guidewire.

11. Further comprising a second guide wire, The kit of claim 10 , wherein the second guidewire is identical to the guidewire.

12. The kit described in claim 10, wherein the first elongated implant and / or the second elongated implant are threaded.

13. The kit described in claim 9, wherein the free end of the second segment of the second portion of the guide wire includes a sharp tip.

14. The kit described in claim 9, wherein the third tapered segment has one or more cutting grooves.

15. A surgical kit for performing fracture fixation using a cannulated implant having a head and an at least partially threaded shaft, comprising: a guidewire having two or more diameters configured to deliver the cannulated implant into a fractured bone by intramedullary fixation; a first portion having a first outer diameter D1; a second portion including a first segment, a second segment, and a third tapered segment, the first segment having a second outer diameter D2 greater than the first outer diameter D1, the second segment having a third outer diameter D3 less than the second outer diameter D2, and the third tapered segment extending between the first segment and the second segment; the cannulated implant is configured to be slidably mounted over the first portion of the guidewire; a guidewire, the second outer diameter D2 being substantially the same as a minor or root diameter of the cannulated implant; The size adjustment tool a driver configured to engage the head of the implant to insert the implant into the bone; A kit comprising:

16. Further comprising a sterile and sealed package, 16. The kit of claim 15, wherein the guidewire, the sizing tool, and the driver are enclosed within the sterile and sealed package.

17. The kit described in claim 16, wherein the guide wire, the sizing tool, and / or the driver are configured for single use.

18. The kit described in claim 16, wherein the guide wire, the sizing tool, and / or the driver are sterilized after each use so that they can be reused.

19. The kit described in claim 15, wherein the free end of the second segment of the second portion of the guide wire includes a sharp tip.

20. The kit described in claim 15, wherein the third tapered segment has one or more cutting grooves.

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