A guide for minimally invasive calcaneal fracture screw placement

Abstract

The application discloses a minimally invasive guide for placing a screw into a calcaneal fracture, and relates to the field of surgical instruments for calcaneal fractures. The guide comprises a U-shaped handle, one end of the handle is provided with a guide tip, and the other end is detachably connected with guide sleeves of different inner diameter specifications through a threaded sleeve joint. The guide sleeves and the guide tip are coaxial. The threaded sleeve joint comprises a joint base, a multi-petal elastic sleeve and a fastening nut, and the guide sleeves are locked through taper surface cooperation. During use, the guide sleeves with matched inner diameters can be selected according to the diameter of the Kirschner wire, so that the radial gap is significantly reduced, the guiding precision is improved, the Kirschner wire is prevented from deviating, one handle can be adapted to multiple specifications, the cost of surgical instruments is reduced, and the sleeves are convenient to replace and reliable in connection.

Description

Technical Field

[0001] This invention relates to the field of surgical instruments for calcaneal fractures, and more particularly to a guide for minimally invasive screw placement in calcaneal fractures. Background Technology

[0002] In the internal fixation treatment of fractures of the suspensory process of the calcaneus or collapsed fractures of the posterior articular surface of the calcaneus, percutaneous placement of Kirschner wires or cannulated screws is a common surgical technique for achieving anatomical reduction and rigid fixation. To ensure accurate penetration of the Kirschner wire into the center of the suspensory process and avoid damage to the subtalar articular surface and surrounding blood vessels and nerve bundles, surgeons often use a guide device for pre-placement. A new type of arc-shaped handle guide device has a positioning tip and a hollow sleeve at each end. The positioning tip is placed against the target exit point of the suspensory process, and the Kirschner wire is then inserted along the hollow sleeve, thus clarifying the implantation path. This type of device is simple in structure and convenient to operate, and is already in clinical use.

[0003] However, existing guide devices mostly use a single, fixed structure where the hollow sleeve and handle are integrated. This presents the following technical drawbacks:

[0004] 1. Existing guide sleeves typically have a fixed inner diameter, usually the maximum inner diameter, designed to be compatible with all commonly used Kirschner wire diameters (e.g., 2.0mm, 2.5mm). However, if a smaller diameter Kirschner wire is used, a gap will inevitably exist between the Kirschner wire and the inner wall of the sleeve. When using finer Kirschner wires, an excessively large gap in the sleeve can easily cause the Kirschner wire to deviate from its path during insertion, with the tip deviating from the preset axis. This ultimately affects the guiding accuracy of screw insertion and may even cause bone wall perforation, leading to fixation failure.

[0005] 2. In clinical practice, doctors may need to use Kirschner wires of different diameters for patients with different fracture types or body types. The thickness and length of the wire vary depending on the type and location of the fracture to meet different clinical needs. However, traditional one-piece sleeves cannot be replaced, forcing doctors to prepare multiple sets of guide devices of different specifications, which increases the cost of surgical instruments and the difficulty of managing the operating table.

[0006] Therefore, there is an urgent need for a guide sleeve structure that can be replaced at any time and whose inner diameter matches the diameter of the Kirschner wire, so as to improve guidance accuracy and instrument versatility while ensuring connection stability. Summary of the Invention

[0007] This invention aims to provide a guide for minimally invasive calcaneal fracture screw insertion. By replacing the guide sleeve structure with one whose inner diameter matches the Kirschner wire diameter, it improves guidance accuracy and instrument versatility while ensuring connection stability. It addresses the problems of excessive sleeve gaps when using thinner Kirschner wires, which easily leads to wire deviation during insertion, and the inability to replace traditional one-piece sleeves, forcing doctors to prepare multiple guide devices of different sizes.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A guide for screw placement in minimally invasive calcaneal fractures includes a handle, the handle having a U-shaped structure, a guide tip at one end of the handle, and a guide sleeve at the end of the handle away from the guide tip. The guide sleeve has a hollow tubular structure and is detachable and replaceable with the handle. The guide sleeve is a replacement part with different inner diameters.

[0010] Furthermore, the guide tip and the guide sleeve are coaxial.

[0011] Furthermore, the guide sleeve and the grip are detachably replaceable via a threaded ferrule connector. The threaded ferrule connector includes a connector base, an elastic ferrule, and a fastening nut. The connector base is fixed to the end of the grip, and the side of the connector base extends outward to form an elastic ferrule. The elastic ferrule has a multi-lobed structure, and the outer surface of the elastic ferrule is threadedly connected to the inner surface of the fastening nut. The front end of the elastic ferrule has an outer conical surface, and the rear end of the inner wall of the fastening nut has an inner conical surface that abuts against the outer conical surface. The threaded ferrule connector has a central channel through which the guide sleeve passes, and all replacement parts of the guide sleeve have the same outer diameter dimension that matches the central channel.

[0012] Furthermore, a Kirschner wire is movably installed inside the guide sleeve.

[0013] Furthermore, the inner diameter of the guide sleeve is 1 to 2.5 mm.

[0014] Furthermore, the inner diameter of the guide sleeve includes the following specifications: 1.0mm, 1.5mm, 2mm and 2.5mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Significantly improves guiding accuracy and reduces Kirschner wires.

[0017] 1. By setting guide sleeves with different inner diameters (e.g., 1.0mm, 1.5mm, 2.0mm, 2.5mm, etc.), the guide sleeve with an inner diameter matching the actual diameter of the selected Kirschner wire can be chosen during the procedure. Because the circumferential gap between the inner wall of the guide sleeve and the Kirschner wire is significantly reduced, the Kirschner wire is effectively constrained during its advancement stroke, greatly eliminating radial wobble. This ensures the correct puncture path of the Kirschner wire and avoids fixation failure due to the guide wire entering the joint surface or being improperly positioned.

[0018] 2. The threaded ferrule connector structure allows for quick replacement of guide sleeves with different inner diameters and even different guide lengths using the same handle. Hospitals only need to purchase one handle and a complete set of guide sleeve replacement components to meet the surgical needs of various Kirschner wire diameters and fracture types, eliminating the need to purchase a complete set of guides for each Kirschner wire diameter, significantly reducing instrument purchase costs and management burden. Attached Figure Description

[0019] Figure 1 A schematic diagram of a guide for screw placement in a minimally invasive calcaneal fracture.

[0020] Figure 2 A partial schematic diagram of a guide for screw placement in a minimally invasive calcaneal fracture.

[0021] Figure 3 A partial cross-sectional schematic diagram of a guide for screw placement in a minimally invasive calcaneal fracture.

[0022] Figure 4 This is a partially exploded cross-sectional view of a guide device for screw placement in a minimally invasive calcaneal fracture.

[0023] The reference numerals in the accompanying drawings include:

[0024] 1. Handle; 2. Guide tip; 3. Guide sleeve; 4. Threaded ferrule connector; 41. Connector base; 42. Elastic ferrule; 421. Outer conical surface; 43. Fastening nut; 431. Inner conical surface; 44. Center channel. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0026] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only structures closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0027] In the description of this application, it should be understood that the terms "end", "front", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] Example 1

[0029] Please see Figures 1 to 4 A guide for screw placement in minimally invasive calcaneal fractures includes a handle 1. The handle 1 has a U-shaped structure and is integrally formed from medical-grade 304 stainless steel, with a sandblasted and passivated surface for easy gripping and high-temperature, high-pressure sterilization. One end of the handle 1 is provided with a guide tip 2, which is a conical tip used to abut against the target exit point of the calcaneal protuberance during surgery. The end of the handle 1 furthest from the guide tip 2 is provided with a guide sleeve 3.

[0030] The guide tip 2 and the guide sleeve 3 are coaxial. When the guide sleeve 3 is installed on the grip 1, the central axis of the guide sleeve 3 and the tip of the guide tip 2 are on the same straight line. This coaxial relationship is ensured by the U-shaped structure of the grip 1.

[0031] The guide sleeve 3 has a hollow tubular structure and is detachably replaceable with the handle 1: a threaded ferrule connector 4 is fixed to the proximal end of the handle 1, and the guide sleeve 3 is detachably connected to the handle 1 through this threaded ferrule connector 4. The guide sleeve 3 is a replaceable part with different inner diameters, that is, multiple guide sleeves 3 with different inner diameters can be fitted to the same handle 1. The outer diameter of each guide sleeve 3 is consistent to fit the threaded ferrule connector 4, while the inner diameter corresponds to the diameter of commonly used Kirschner needles in clinical practice.

[0032] In this embodiment, the guide sleeve 3 and the grip 1 are detachably replaceable via a threaded ferrule connector 4. For details, please refer to... Figures 2 to 4 The threaded ferrule connector 4 includes a connector base 41, an elastic ferrule 42, and a fastening nut 43. The connector base 41 is fixed to the end of the handle 1. The side of the connector base 41 extends outward to form the elastic ferrule 42. The elastic ferrule 42 has a multi-lobed structure, such as three or four lobes evenly distributed circumferentially. In this embodiment, it is a four-lobed structure, with axial slits between each lobe to provide radial contraction elasticity. The outer surface of the elastic ferrule 42 has external threads, and the inner surface of the fastening nut 43 has internal threads. The elastic ferrule 42 and the fastening nut 43 form a threaded connection. The front end of the elastic ferrule 42 has an outer conical surface 421, and the rear end of the inner wall of the fastening nut 43 (i.e., the end away from the screwing direction) has an inner conical surface 431 that abuts against the outer conical surface 421.

[0033] The threaded ferrule connector 4 is provided with a central channel 44 through which the guide sleeve 3 passes. The central channel 44 passes through the fastening nut 43, the elastic ferrule 42, and the connector base 41 in sequence. All replacement parts of the guide sleeve 3 have the same outer diameter size that matches the central channel 44, thereby ensuring that the guide sleeve 3 of any inner diameter can be smoothly inserted into the central channel 44 and locked by tightening the fastening nut 43.

[0034] During assembly, the operator first inserts the guide sleeve 3 of the selected inner diameter into the central channel 44. Then, the operator places the fastening nut 43 onto the elastic sleeve 42 and manually tightens it. During tightening, the inner conical surface 431 of the fastening nut 43 interacts with the outer conical surface 421 of the elastic sleeve 42, forcing the multi-lobed structure of the elastic sleeve 42 to contract radially, thereby pressing against the outer wall of the guide sleeve 3 and achieving axial fixation. When the guide sleeve 3 needs to be replaced, the operator loosens the fastening nut 43 in the opposite direction, and the elastic sleeve 42 elastically returns to its original position, allowing the original sleeve to be easily pulled out and a sleeve of another specification to be inserted.

[0035] After assembly, the guide sleeve 3 can accommodate the Kirschner wires that are matched with it. The two are in clearance fit, with the clearance on one side controlled within the range of 0.02mm to 0.05mm, which ensures that the Kirschner wires can be pushed in smoothly while avoiding significant wobbling.

[0036] The inner diameter of the guide sleeve 3 ranges from 1.0mm to 2.5mm. Specifically, the guide sleeve 3 has four inner diameter specifications: 1.0mm, 1.5mm, 2.0mm, and 2.5mm. All specifications of the guide sleeve 3 have the same outer diameter and inner diameters of 1.0mm, 1.5mm, 2.0mm, and 2.5mm, respectively. The inner walls of all guide sleeves are precision ground and polished to reduce friction during Kirschner wire advancement. It should be noted that this embodiment only provides guide sleeves 3 for commonly used clinical Kirschner wire sizes and does not mean that this solution only includes these four specifications. This solution can be designed with guide sleeves 3 of various inner diameters and even different lengths based on clinical requirements and actual needs; these will not be elaborated upon here.

[0037] Example 2

[0038] This embodiment provides a method for using the guide described in Embodiment 1, including the following steps:

[0039] 1. Preoperative preparation: Determine the required Kirschner wire diameter (e.g., 2.0 mm) based on preoperative imaging measurements. Select a guide sleeve 3 with an inner diameter of 2.0 mm from the replacement sleeve assembly. Insert the guide sleeve 3 into the central channel 44 of the threaded ferrule connector 4 at the proximal end of the handle 1. Manually tighten the fastening nut 43 until the elastic ferrule 42 grips the guide sleeve 3.

[0040] 2. Positioning: Insert the guide tip 2 through a percutaneous puncture or small incision, accurately abutting against the target needle exit point of the carrier tube, while simultaneously pointing the inlet end of the guide sleeve 3 towards the preset needle entry point.

[0041] 3. Guided puncture: Insert the Kirschner wire into the proximal end of the guide sleeve 3 and advance it along the inner wall of the sleeve until the tip of the Kirschner wire emerges from the distal end of the guide sleeve 3, so that it passes through the suspensory process bone layer for fixation.

[0042] 4. Subsequent operations: Remove the guide, retain the Kirschner wire for direct fixation, or use it as a guide to insert a hollow drill and hollow screw along the Kirschner wire to complete the internal fixation.

[0043] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific structures are described and shown as examples. However, the method process of the present invention is not limited to the specific structures described and shown, and those skilled in the art can make various changes, modifications, and additions after understanding the spirit of the present invention.

[0044] In this invention, features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any non-inventive modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A guide for screw placement in minimally invasive calcaneal fractures, characterized in that, Includes a grip (1), the grip (1) has a U-shaped structure, one end of the grip (1) is provided with a guide tip (2), the end of the grip (1) away from the guide tip (2) is provided with a guide sleeve (3), the guide sleeve (3) has a hollow tubular structure, the guide sleeve (3) and the grip (1) are detachable and replaceable, and the guide sleeve (3) is a replacement part with different specifications and sizes of inner diameter.

2. The guide for minimally invasive calcaneal fracture screw placement according to claim 1, characterized in that, The guide tip (2) and the guide sleeve (3) are coaxial.

3. The guide for minimally invasive calcaneal fracture screw placement according to claim 1, characterized in that, The guide sleeve (3) and the handle (1) are detachably replaceable through a threaded ferrule connector (4). The threaded ferrule connector (4) includes a connector base (41), an elastic ferrule (42), and a fastening nut (43). The connector base (41) is fixed to the end of the handle (1). The side of the connector base (41) extends outward to form the elastic ferrule (42). The elastic ferrule (42) has a multi-lobed structure. The outer surface of the elastic ferrule (42) and the inner surface of the fastening nut (43) are connected by threads. The front end of the elastic ferrule (42) is provided with an outer conical surface (421). The rear end of the inner wall of the fastening nut (43) is provided with an inner conical surface (431) that abuts against the outer conical surface (421). The threaded ferrule connector (4) is provided with a central channel (44) through which the guide sleeve (3) passes. Replacement parts of the guide sleeve (3) all have the same outer diameter size that matches the central channel (44).

4. The guide for minimally invasive calcaneal fracture screw placement according to claim 1, characterized in that, Kirschner wires are movably installed inside the guide sleeve (3).

5. A guide for minimally invasive calcaneal fracture screw placement according to claim 1, characterized in that, The inner diameter of the guide sleeve (3) is 1 to 2.5 mm.

6. The guide for minimally invasive calcaneal fracture screw placement according to any one of claims 1-5, characterized in that, The inner diameter of the guide sleeve (3) includes 1.0mm, 1.5mm, 2mm and 2.5mm.

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