Proximal femur inner side reduction spreader for preventing wedge effect of intertrochanteric fracture

Abstract

The invention relates to a proximal femur inner side reduction dilator for preventing the wedge effect of intertrochanteric fracture. The proximal femur inner side reduction dilator comprises a central upright post and an ejector rod, a cylindrical insertion rod is formed at the lower part of the central stand column and is used for being inserted and fixed in a reserved fixing hole of an operating bed, and a mounting hole is transversely formed in the upper part of the central stand column in a penetrating manner; the mounting hole extends along the up-down direction of the upper part of the central upright post; a jacking block is mounted in the mounting hole; through friction force between the jacking block and the left side face and the right side face of the mounting hole, the jacking block is statically kept at a preset height position in the mounting hole; a threaded hole is formed in the jacking block in a penetrating manner in the front-back direction; the front end of the ejector rod is rotatably provided with an ejector head assembly, the rear end of the ejector rod is fixedly provided with a wheel-shaped handle, and an external thread is formed in the middle of the ejector rod. The middle of the ejector rod is installed in a threaded hole of the jacking block, and the ejector head assembly extends to the position in front of the jacking block and is used for pressurizing the inner side of the near end of the thigh of a subject to correspond to the thigh lesser trochanter or the inner side cortex projection area.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to an orthopedic surgical aid, and more particularly to a dedicated reduction device for controlling the push of the proximal medial cortex of the femur during intramedullary nail fixation surgery for intertrochanteric fractures of the femur, in order to prevent or correct the "wedge effect". Background Technology

[0002] Intertrochanteric fractures of the femur are common hip fractures, and the current mainstream treatment is closed reduction and intramedullary nailing. A key challenge during surgery is the "wedge effect." When a fracture occurs, the medial cortex of the proximal femur often loses support due to compression or comminutedness, causing the distal fracture fragments to shift medially during reduction, forming a wedge-shaped gap on the medial side of the fracture ends. If this gap fails to close, it will lead to: 1) Deterioration of the mechanical environment of internal fixation: Intramedullary nails and spiral blades are subjected to abnormal shear stress, increasing the risk of internal fixation failure (such as cutout or breakage).

[0003] 2) Poor fracture healing: The presence of gaps affects callus growth and may lead to delayed healing or non-healing.

[0004] 3) Difficulty in reduction: It is difficult to effectively restore the continuity of the medial cortex by relying solely on axial traction and manual reduction. It is often necessary to enlarge the incision for direct vision reduction, which increases surgical trauma, bleeding and infection risk.

[0005] Currently, there is a lack of specialized tools in clinical practice capable of performing precise and controllable lateral-to-medial reduction of the proximal femoral cortex under minimally invasive conditions to actively eliminate the wedge-shaped gap. Surgeons often rely on experience-based techniques or indirect manipulation with general-purpose instruments, resulting in difficulty controlling the pushing force and direction, and inconsistent outcomes. Summary of the Invention

[0006] In view of the above problems, this application aims to provide a proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric fractures of the femur.

[0007] This application discloses a proximal medial femoral reduction and dilator for preventing wedge effect in intertrochanteric fractures of the femur, which includes: a central column and a top rod; The lower part of the central column has a cylindrical insert rod for insertion and fixation in a pre-drilled hole in the operating table, positioning the central column at the subject's groin area. A mounting hole is formed transversely through the upper part of the central column. The left and right sides of the mounting hole are inclined outwards, forming an "eight"-shaped opening that is wider at the front and narrower at the back. The mounting hole extends vertically along the upper part of the central column. A clamping block is installed in the mounting hole. The left side of the clamping block presses against the left side of the mounting hole, and the right side of the clamping block presses against the right side of the mounting hole. Through the friction between the clamping block and the left and right sides of the mounting hole, the clamping block remains stationary at a predetermined height within the mounting hole. A threaded hole is formed through the clamping block in the front-to-back direction. The front end of the push rod is rotatably mounted with a push head assembly, the rear end of the push rod is fixedly mounted with a wheel-shaped handle, and the middle part of the push rod has an external thread. The middle part of the push rod is installed in the threaded hole of the clamping block. The push head assembly extends to the front of the clamping block to apply pressure to the medial aspect of the proximal thigh of the subject, corresponding to the projection area of ​​the lesser trochanter or medial cortex of the femur. The pressure applied to the subject by the push head assembly is adjusted by adjusting the length of the push rod extending from the clamping block to prevent the wedge effect of intertrochanteric fracture of the femur. The wheel-shaped handle is located at the rear of the clamping block and is used to adjust the length of the push rod extending from the clamping block.

[0008] Preferably, the top assembly includes a base plate and an elastic pad; the elastic pad is fixed to the front side of the base plate; an annular retaining ring is integrally formed at the center of the rear side of the base plate; an annular protrusion is integrally formed on the outer peripheral surface of the front end of the top rod; the protrusion of the top rod is rotatably mounted in the retaining ring of the base plate.

[0009] Preferably, the front side of the elastic pad is formed as an arc-shaped concave surface.

[0010] Preferably, the central column, top rod, clamping block, and base plate are made of medical-grade polymer material; the elastic pad is made of medical-grade silicone or polyurethane.

[0011] Preferably, the top assembly is rectangular in shape when viewed from the front-to-back direction.

[0012] The proximal femoral medial reduction and diverter of this application for preventing wedge effect in intertrochanteric femoral fractures can, percutaneously and precisely, apply a continuous and adjustable pushing force to the proximal medial cortex of the femur in intramedullary nailing surgery for intertrochanteric femoral fractures, thereby effectively preventing or correcting the "wedge effect," closing the medial gap, improving the quality of reduction and the stability of internal fixation, and reducing the reliance on open reduction. Attached Figure Description

[0013] Figure 1This is a three-dimensional structural diagram of the proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric fractures of the femur as described in this application.

[0014] Figure 2 for Figure 1 A cross-sectional schematic diagram of a proximal medial femoral reduction and diverter used to prevent wedge effect in intertrochanteric fractures of the femur.

[0015] Figure 3 for Figure 1 A three-dimensional structural diagram of the central column of a proximal femoral medial reduction and diverter used to prevent wedge effect in intertrochanteric fractures of the femur.

[0016] Figure 4 for Figure 3 A rear view structural diagram of the central column.

[0017] Figure 5 for Figure 3 A schematic diagram of the main structure of the central column.

[0018] Figure 6 This is a schematic diagram of the three-dimensional structure of the clamping block.

[0019] Figure 7 for Figure 6 A top view of the top clamping block.

[0020] Figure 8 This is a three-dimensional structural diagram of the top assembly.

[0021] Figure 9 for Figure 8 A side view of the top component.

[0022] Figure 10 for Figure 8 A cross-sectional structural diagram of the top assembly.

[0023] Figure 11 This is a schematic diagram of the main structure of the push rod. Detailed Implementation

[0024] The proximal medial femoral reduction and diverter of this application, for preventing wedge effect in intertrochanteric fractures of the femur, will now be described in detail with reference to the accompanying drawings.

[0025] The present application discloses a proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric fractures of the femur, which includes: a central column 1 and a top rod 3.

[0026] The lower part of the central column 1 has a cylindrical insert rod 11 for insertion and fixing in the reserved fixing hole of the operating table, so that the central column is located at the crotch position of the subject.

[0027] The diameter of the upper part of the central column 1 is larger than that of the upper part. A mounting hole 12 is formed horizontally through the upper part of the central column 1; the left and right sides of the mounting hole 12 are inclined outwards, so that the mounting hole forms an "eight"-shaped opening that is wider at the front and narrower at the back; the mounting hole 12 extends vertically along the upper part of the central column; a clamping block 2 is installed in the mounting hole 12; the left side of the clamping block 2 presses against the left side of the mounting hole 12, and the right side of the clamping block 2 presses against the right side of the mounting hole 12. Through the friction between the clamping block 2 and the left and right sides of the mounting hole 12, the clamping block 2 is held statically at a predetermined height position in the mounting hole 12; a threaded hole 21 is formed through the clamping block 2 in the front-back direction.

[0028] The front end of the push rod 3 is rotatably mounted with a push head assembly, the rear end of the push rod 3 is fixedly mounted with a wheel-shaped handle 6, and the middle part of the push rod 3 has an external thread.

[0029] The middle part of the push rod 3 is installed in the threaded hole 21 of the clamping block 2. The push head assembly extends to the front of the clamping block 2 to apply pressure to the medial aspect of the proximal thigh of the subject, corresponding to the projection key area of ​​the lesser trochanter of the femur or the medial cortex. The pressure applied to the subject by the push head assembly is adjusted by adjusting the length of the push rod 3 extending from the clamping block 2 to prevent the wedge effect of intertrochanteric fracture of the femur. The wheel-shaped handle 6 is located at the rear of the clamping block 2 and is used to adjust the length of the push rod 3 extending from the clamping block 2. The rotational motion of the push rod is converted into a stable linear thrust through the engagement of the external thread in the middle of the push rod with the threaded hole of the clamping block, and can be reliably locked at any position to prevent retraction.

[0030] The top assembly includes a base plate 4 and an elastic pad 5; the elastic pad 5 is fixed to the front side of the base plate 4; an annular retaining ring 41 is integrally formed at the center of the rear side of the base plate 4, and an annular groove 42 is formed on the inner circumferential surface of the retaining ring 41; an annular protrusion 31 is integrally formed on the outer circumferential surface of the front end of the top rod 3; the protrusion 31 of the top rod 3 is rotatably installed in the retaining ring 41 of the base plate 4, and the protrusion 31 engages in the groove 42 to prevent the top assembly from falling off the top rod 3.

[0031] The front side of the elastic pad 5 is formed into an arc-shaped concave surface, which facilitates the fixation of the top assembly on the inner thigh of the subject, corresponding to the lesser trochanter of the femur or the key area of ​​the medial cortex. The elastic pad 5 provides a soft, non-slip contact interface, which can effectively transmit thrust and disperse pressure, protecting the skin and soft tissue.

[0032] The central column 1, top rod 3, clamping block 2, and base plate 4 are made of medical polymer material; the elastic pad 5 is made of medical silicone or polyurethane.

[0033] The top component is rectangular in shape when viewed from the front and back.

[0034] The steps for this application are as follows.

[0035] Insert the lower part of the central column of the retractor into the pre-drilled hole on the operating table, positioning the retractor at the patient's groin. Secure the elastic pad against the proximal medial aspect of the thigh (corresponding to the location of the fracture fragment requiring jacking). The surgeon rotates the wheel-shaped handle, driving the jacking rod and thus smoothly moving the entire jacking assembly towards the patient. Under C-arm fluoroscopic monitoring, the displacement of the jacking can be precisely controlled, applying a continuous, controllable lateral-to-inward jacking force to the proximal medial femoral fracture fragment. This effectively counteracts the medial defect causing the "wedge effect," ensuring close medial alignment of the fracture ends. Once adjusted, the mechanical self-locking mechanism ensures the jacking force remains stable throughout the internal fixation procedure.

[0036] Installation and Positioning: After anesthesia, the patient should be placed in a supine position. Securely fix the central column of the retractor to the operating table, with the top component corresponding to the lesser trochanter of the femur or the key area of ​​the medial cortex, and pre-pinch it against the body surface.

[0037] Initial reduction: Axial traction of the affected limb is routinely performed for initial reduction of the fracture.

[0038] Push-and-reduction (to resolve wedge effect): Under C-arm fluoroscopy, the surgeon slowly rotates the wheel-shaped handle. By adjusting the push rod, the push-and-reduction assembly is smoothly advanced, applying continuous pressure to the medial aspect of the proximal femur. Changes in the fracture gap are observed under fluoroscopy until satisfactory medial cortical alignment is achieved and the wedge-shaped gap disappears.

[0039] Locking and maintaining: After a satisfactory reset, the device's own mechanical structure can automatically maintain the pushing force.

[0040] Internal fixation completed: With the spreader maintaining medial reduction, the intramedullary nail was successfully inserted, the proximal spiral blade was locked, and the distal locking was completed.

[0041] Removal of the device: After internal fixation is completed, rotate the wheel-shaped handle in the opposite direction to loosen the lock and remove the spreader.

[0042] Beneficial effects Precisely addressing clinical challenges: Directly targeting the mechanical causes of the "wedge effect," it provides an active and controllable solution, significantly improving the success rate of closed reduction in complex fractures.

[0043] Minimally invasive and intuitive operation: Percutaneous procedure, eliminating the need for additional incisions for repositioning. The screw drive mechanism offers precise adjustment and stable direction, providing clear tactile feedback for the surgeon. Combined with fluoroscopy, the repositioning process is controllable and visually guided.

[0044] Improved internal fixation effectiveness: By eliminating the medial space, a more physiological mechanical load-bearing environment is created for the intramedullary nail system, which potentially reduces the risk of internal fixation failure and promotes fracture healing.

[0045] Simple and reliable structure: It adopts a mature mechanical thread transmission and locking principle, which makes the structure stable, the thrust maintained reliably, and the parts are few, making it easy to disinfect and maintain.

[0046] Improved surgical safety: Reduced extensive soft tissue dissection and repeated manual manipulations in pursuit of repositioning, thus lowering the risk of bleeding, infection, and iatrogenic injury.

Claims

1. A proximal medial femoral reduction and dispersing device for preventing wedge effect in intertrochanteric femoral fractures, comprising: Central column and top rod; The lower part of the central column has a cylindrical insert rod for insertion and fixation in a pre-drilled hole in the operating table, positioning the central column at the subject's groin area. A mounting hole is formed transversely through the upper part of the central column. The left and right sides of the mounting hole are inclined outwards, forming an "eight"-shaped opening that is wider at the front and narrower at the back. The mounting hole extends vertically along the upper part of the central column. A clamping block is installed in the mounting hole. The left side of the clamping block presses against the left side of the mounting hole, and the right side of the clamping block presses against the right side of the mounting hole. Through the friction between the clamping block and the left and right sides of the mounting hole, the clamping block remains stationary at a predetermined height within the mounting hole. A threaded hole is formed through the clamping block in the front-to-back direction. The front end of the push rod is rotatably mounted with a push head assembly, the rear end of the push rod is fixedly mounted with a wheel-shaped handle, and the middle part of the push rod has an external thread. The middle part of the push rod is installed in the threaded hole of the clamping block. The push head assembly extends to the front of the clamping block to apply pressure to the medial aspect of the proximal thigh of the subject, corresponding to the projection area of ​​the lesser trochanter or medial cortex of the femur. The pressure applied to the subject by the push head assembly is adjusted by adjusting the length of the push rod extending from the clamping block to prevent the wedge effect of intertrochanteric fracture of the femur. The wheel-shaped handle is located at the rear of the clamping block and is used to adjust the length of the push rod extending from the clamping block.

2. The proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric femoral fractures according to claim 1, characterized in that: The top assembly includes a base plate and an elastic pad; the elastic pad is fixed to the front side of the base plate; an annular retaining ring is integrally formed at the center of the rear side of the base plate; an annular protrusion is integrally formed on the outer circumferential surface of the front end of the top rod; the protrusion of the top rod is rotatably mounted in the retaining ring of the base plate.

3. The proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric femoral fractures according to claim 2, characterized in that: The front side of the elastic pad is formed into an arc-shaped concave surface.

4. The proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric femoral fractures according to claim 2, characterized in that: The central column, top rod, clamping block, and base plate are made of medical-grade polymer materials; the elastic pads are made of medical-grade silicone or polyurethane.

5. The proximal medial femoral reduction and diverter for preventing wedge effect in intertrochanteric femoral fractures according to claim 2, characterized in that: The top component is rectangular in shape when viewed from the front and back.

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