External fixing device for supracondylar fracture of humerus of child

Abstract

The invention relates to the field of medical instruments, in particular to an external fixing device for supracondylar fracture of humerus of children, which comprises a fixing mechanism main body for physically restraining the fracture broken end of a patient, the fixing mechanism main body is provided with an anti-rotation mechanism and a point pressing mechanism, the anti-rotation mechanism is used for providing pre-screwing force for resisting deformity healing for the far end of the humerus of the patient, and the point pressing mechanism is used for pressing the far end of the humerus of the patient. The point pressing mechanism is used for providing orthopedic force at the preset position so as to maintain the Baumann angle. Fracture far-end rotation can be effectively controlled, and heal of elbow inward / outward turning deformity is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to an external fixation device for supracondylar fractures of the humerus in children. Background Technology

[0002] Supracondylar fractures of the humerus are the most common elbow fractures in childhood, accounting for approximately 50%-70% of all childhood elbow fractures, with the peak age of onset being 3 to 10 years old. Because the epiphyseal plate exists at the distal end of the humerus in children, and the bone in the supracondylar region is thin, falls with the arm extended to brace the body are highly prone to fracture. This area is adjacent to important nerves and blood vessels (such as the brachial artery, median nerve, and radial nerve), and fracture displacement can lead to serious complications such as Volkmann's contracture, resulting in a high rate of disability.

[0003] In treatment, for stable fractures with no or slight displacement (such as Gartland type I), non-surgical external fixation is the first-line clinical treatment. External physical restraint maintains the alignment of the fracture ends, providing a stable and undisturbed biological environment for natural bone healing. Traditional fixation methods typically use a long-arm plaster cast or tubular plaster cast, fixing the affected limb with the elbow flexed at 90 degrees (or adjusting the angle according to fracture stability), the forearm in a neutral or supinated position, and suspending it in front of the chest.

[0004] Although traditional external fixation techniques such as plaster casts and splints have a long history of application and are easy to operate, they have inherent shortcomings in biomechanical control, especially when dealing with children, where many defects are exposed:

[0005] Following a supracondylar fracture of the humerus in children, the proximal shaft is round, while the distal fracture fragment is flat and the medial and lateral cortical bone are unbalanced, making the fracture ends inherently unstable and particularly prone to rotation around the longitudinal axis of the humerus. This rotation is the fundamental mechanical cause of long-term cubitus varus and cubitus valgus deformities. Simultaneously, unconscious forearm rotation during daily life (such as attempting to pick up objects) or limb twisting during sleep can transmit stress through the forearm to the fracture ends, causing slow, insidious rotational displacement of the distal fracture fragment.

[0006] Given the shortcomings of existing technologies, there is an urgent need for an external fixation device that can provide continuous, stable, and intelligent anti-rotational torque to fundamentally prevent deformities, thereby truly serving the rehabilitation treatment of supracondylar fractures of the humerus in a safe, effective, and comfortable manner. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides an external fixation device for supracondylar fractures of the humerus in children, which effectively controls distal fracture rotation and reduces the occurrence of varus / valgus malunion.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: an external fixation device for supracondylar fracture of the humerus in children, comprising a main body of a fixation mechanism for physically restraining the fracture ends of the patient, the main body of the fixation mechanism being provided with an anti-rotation mechanism and a point-pressure mechanism, the anti-rotation mechanism being used to provide a pre-rotation tightening force to the distal end of the humerus of the patient to resist malunion, and the point-pressure mechanism being used to provide a corrective force at a preset position to maintain the Baumann angle.

[0009] The technical principles of the above solution are as follows:

[0010] The core principle is to create a dynamically stable mechanical environment through the synergistic effect of structural anti-rotation and precise point pressure, thereby curbing the two key factors that lead to malunion from the root—distal fracture rotation and changes in the Baumann angle.

[0011] The mechanism of the anti-rotation mechanism: This mechanism is not passively fixed, but actively applies a controllable and continuous pre-rotation force to the distal humerus of the affected limb. This force directly counteracts the inherent rotational tendency caused by the mismatch between the fracture ends' morphology (the proximal round diaphysis and the distal flat bone fragment), as well as the torsional load transmitted to the fracture ends by the child's unconscious forearm rotation during daily activities. By forming a stable "torque," it can effectively neutralize these rotational stresses, ensuring that the distal humerus maintains ideal axial alignment throughout the healing process, thereby fundamentally preventing cubitus varus / valgus deformity that eventually appears due to the accumulation of rotational displacement.

[0012] The orthopedic mechanism of the point-pressure device: This mechanism simulates and solidifies the "pressure pad" technique used in traditional Chinese medicine (Mongolian medicine) reduction. It applies a concentrated, continuous orthopedic force at specific pre-set locations at the fracture site (usually corresponding to key points where the Baumann angle needs to be maintained or corrected). This force, combined with the overall constraint force provided by the main body of the fixation mechanism, forms a lever system:

[0013] The pressure point mechanism acts as a "fulcrum," providing precise counterforce.

[0014] The main body of the fixation mechanism acts as a "lever arm," transmitting the force of the fulcrum to the entire fracture site.

[0015] This lever system actively maintains or fine-tunes the tilt of the distal humeral epiphysis, known as the Baumann angle, a key radiographic indicator for assessing fracture alignment and predicting the elbow's carrying angle. By stabilizing the Baumann angle, it ensures coronal alignment of the fracture, further reducing the risk of malunion.

[0016] During postoperative follow-up, if X-rays reveal slight misalignment of the distal fracture fragment, the doctor can directly adjust the anti-rotation mechanism from the outside of the device to change the magnitude and direction of the applied torque, thereby indirectly and non-invasively correcting the rotational displacement of the distal fracture fragment and restoring it to ideal alignment.

[0017] The above approach has the following beneficial effects:

[0018] 1. This solution, by actively providing anti-rotational torque and precisely maintaining the Baumann angle, directly intervenes in the two fundamental mechanical causes of varus / valgus deformity of the elbow. It can effectively block the slow and hidden displacement during the fracture healing process, thereby significantly reducing the incidence of long-term deformity and improving the treatment effect and functional prognosis of the affected limb.

[0019] 2. This solution differs from the limitations of traditional passive plaster fixation. The anti-rotation and point-pressure functions of this device provide continuous, stable, and directionally controllable mechanical stimulation, creating a "dynamically stable" healing environment. This intelligent mechanical control can proactively adapt to and counteract various unforeseen stresses during rehabilitation, resulting in higher safety.

[0020] 3. This method can correct minor rotational displacements through external adjustment, completely avoiding secondary manual reduction or surgery due to poor alignment. This not only eliminates the risk of the child suffering pain and psychological trauma from re-reduction, but also greatly reduces iatrogenic complications such as soft tissue injury and epiphyseal injury that may be caused by secondary operations.

[0021] Furthermore, the main body of the fixation mechanism includes at least one pair of curved arms, each end of which is provided with an arc-shaped cylinder that conforms to the patient's limb. Each arc-shaped cylinder is provided with a binding mechanism, which is used to bind the adjacent arc-shaped cylinder to the patient's limb.

[0022] Beneficial effects: The arc-shaped cylindrical structure is more in line with the cylindrical anatomical shape of the limb. Through the binding mechanism at both ends, a stable and uniform force-bearing surface can be formed, avoiding the creation of "fulcrums" with excessive local pressure.

[0023] Furthermore, the binding mechanism includes clamping grooves and clamping blocks arranged on adjacent arc-shaped cylinders. The clamping grooves and clamping blocks are respectively arranged inside the arc-shaped cylinders located on different curved arms. When adjacent arc-shaped cylinders are connected, the clamping blocks and clamping grooves slide together.

[0024] An adjustment groove is provided inside the clamping block, and a nut block is slidably fitted inside the adjustment groove. The nut block has a threaded hole.

[0025] The clamping groove has a connector on the side away from the limb, and a screw is slidably fitted into the connector; when the clamping block is slidably fitted into the clamping groove, the threaded hole is threadedly fitted into the screw.

[0026] Beneficial effects: Traditional bandaging or fixation methods rely on the operator's feel, making it difficult to quantify tightness and prone to loosening. This mechanism directly converts the mechanical pressure generated by tightening the screws into stable and repeatable static friction between the clamp and the inner wall of the clamping groove. This mechanical locking method provides connection stiffness and shear resistance far exceeding that of conventional bandaging, ensuring that the articulated arm frame will not loosen or shift due to force during the child's daily activities, thus providing an extremely stable mechanical environment for the fracture ends.

[0027] By sliding the nut block within the adjustment groove, the binding mechanism achieves stepless adjustment of the fixed circumference. This means that the same device can be precisely adapted to the limbs of children of different ages and body sizes through simple adjustments. This not only greatly improves the versatility of the device and reduces the cost for hospitals to stock multiple specifications and models, but also enables personalized fixation for each child, avoiding insecure fixation or discomfort due to incompatible models.

[0028] During treatment, the child's limbs may become thinner due to swelling reduction or muscle atrophy, requiring re-fastening of the fixation. Our facility can easily complete the adjustment by simply tightening or loosening the screws using tools, without replacing or damaging any parts.

[0029] Furthermore, the arc-shaped cylinder near the patient's forearm is slidably connected to the curved arm. The anti-rotation mechanism includes a groove opened in any one of the arc-shaped cylinders near the patient's forearm, and an incomplete gear ring is provided in the groove. A first knob is provided at one end of the curved arm near the incomplete gear ring. The first knob is rotatably engaged with the curved arm. A worm is coaxially provided on the first knob. The worm meshes with a worm wheel, and the worm wheel meshes with the incomplete gear ring.

[0030] Beneficial effects: By rotating the first knob to drive the worm gear system, which ultimately rotates the incomplete gear ring integrated with the arc-shaped cylinder, this design allows for extremely precise adjustment of the angle between the arc-shaped cylinder in the forearm segment and the upper arm segment. This adjustment directly corresponds to the control of the forearm pronation / supination posture, thereby precisely applying a quantifiable and directionally controllable corrective torque to the distal fracture site, fundamentally and proactively correcting and preventing rotational deformities.

[0031] The worm gear drive has an inherent reverse self-locking characteristic. Once the first knob stops turning, the system immediately locks, preventing the worm gear and incomplete gear ring from driving the worm in reverse. This means that regardless of any unconscious forearm rotational stress the child experiences in daily life, or limb twisting during sleep, the mechanism acts like a "mechanical lock," effectively resisting and eliminating the interference of these stresses on the fracture ends, ensuring the continuity and reliability of the anti-rotation effect, and avoiding the occurrence of hidden displacement in traditional fixation methods.

[0032] Furthermore, the pressure point mechanism includes several clamping plates circumferentially fixed inside the arc-shaped cylinder. Each clamping plate has a movable cavity on its inner side. Several pressure pads are slidably connected to the movable cavity near the limb. A lead screw and a rotating shaft are rotatably connected inside the movable cavity. A nut seat is threaded onto the lead screw, and a groove is provided on the side of the nut seat near the pressure pad. A cam block is eccentrically provided on the rotating shaft, and the cam block slides in contact with the side wall of the groove and the pressure pad respectively.

[0033] The clamp plate is fitted with a second knob and a lever. The second knob is fixedly connected to the lead screw on the same axis, and the lever is connected to the rotating shaft on the same axis.

[0034] Beneficial effects: By driving the lead screw through the second knob, the linear displacement of the nut seat is controlled, thereby precisely setting the longitudinal position of the pressure pad; simultaneously, by driving the rotating shaft and cam through the dial, the pressure applied by the pressure pad to the limb surface is infinitely adjusted by utilizing the change in the eccentricity of the cam. This decoupled design of "position" and "pressure" allows doctors to accurately place the orthopedic fulcrum at key bone points (such as the position required to maintain the Baumann angle) based on imaging results, like operating a precision instrument, and independently apply the most appropriate orthopedic force, realizing the digitalization and precision of orthopedic treatment.

[0035] Furthermore, the clamp is also provided with a limiting mechanism for restricting the rotation of the lever. The limiting mechanism includes a toothed groove on the clamp, and the lever slides in cooperation with the rotating shaft. When the lever is inserted into the toothed groove, the lever engages with the toothed groove.

[0036] Beneficial effects: This mechanism forms a purely mechanical, rigid interlock by directly inserting and engaging the pry bar into a rigid toothed groove. This locking method is extremely reliable and can effectively resist various disturbances from inside the device (such as the tendency of the cam to spring back) or from outside (such as the child's clothing rubbing against it or unintentional touching), completely eliminating the attenuation or loss of orthopedic pressure caused by accidental rotation of the pry bar, and ensuring the long-term continuity and stability of orthopedic force.

[0037] Furthermore, the clamp plate is also equipped with displacement scale marks and pressure scale marks; the displacement scale marks correspond to the displacement distance of the nut seat in the movable cavity; the pressure scale marks correspond to the pressure between the cam block and the pressure pad after the dial rotates to a preset angle.

[0038] Beneficial effects: The scale markings provide doctors with an objective and visual numerical benchmark for their operations. Doctors can directly set target displacement and pressure values ​​for adjustment based on imaging measurements, rather than relying on vague tactile estimations. This "guided" approach greatly eliminates treatment deviations caused by differences in individual experience, making each adjustment precise and controllable, and significantly improving the repeatability and consistency of treatment.

[0039] Furthermore, pressure sensors are installed on the inner side of the splint to collect the pressure value between the splint and the patient's limb; the pressure sensors are electrically connected to a display unit to display the pressure value.

[0040] Beneficial effects: Traditional fixation relies entirely on the doctor's personal experience, which involves great uncertainty and blind spots. This design uses pressure sensors to continuously and accurately convert the interaction force between the splint and the limb into objective digital signals, which are then presented in real time through a display unit.

[0041] When postoperative limb swelling worsens or the device is accidentally displaced, causing local pressure to rise abnormally and approach the danger threshold, doctors or family members can immediately receive a visual warning through the numerical changes of the display unit. This enables early warning and timely intervention, effectively preventing serious iatrogenic injuries such as skin pressure sores and nerve and blood vessel compression.

[0042] When the display unit indicates that the pressure value is consistently lower than the effective treatment window, it can promptly warn of the potential risk of loosening or failure of the fixation, reminding the doctor to tighten or adjust it to prevent the fracture from shifting again due to insecure fixation, thus ensuring the stability and reliability of the fixation effect throughout the entire treatment cycle.

[0043] Furthermore, it also includes a control unit and an alarm notification unit; the control unit is used to control the operation of the alarm notification unit based on the pressure value; the alarm notification unit is used to send alarm notification signals to the outside.

[0044] Beneficial effects: By continuously and automatically interpreting the pressure signal through the control unit, once the pressure value exceeds the preset safety threshold, the system will immediately and automatically activate the alarm without human intervention, realizing 24-hour uninterrupted safety monitoring and fundamentally eliminating safety hazards caused by untimely human observation.

[0045] Furthermore, it also includes a temperature sensor and a blood flow sensor; the temperature sensor is used to monitor the temperature of the patient's limb tissues; the blood flow sensor is used to monitor the blood supply to the patient's limbs; the control unit is also used to control the operation of the alarm notification unit based on the temperature and blood supply conditions.

[0046] Beneficial Effects: Following a supracondylar fracture of the humerus in children, compression or spasm of the brachial artery can lead to impaired limb blood supply, potentially causing irreversible and disabling complications such as Volkmann's ischemic contracture. This device directly and objectively monitors the microcirculation in the distal limb using a blood flow sensor. If blood flow parameters show an abnormal decline, the control unit immediately activates an alarm. This provides doctors with a crucial window of opportunity far exceeding traditional methods (such as relying on the child's complaints or manual examination), making intervention possible before irreversible damage occurs.

[0047] Abnormally elevated local tissue temperature is a sensitive indicator of early infection and severe inflammatory responses. Temperature sensors continuously monitor changes in temperature distribution across the limb surface, and the control unit triggers an alarm when an abnormal temperature rise occurs. This allows the device to simultaneously monitor two types of risks: those caused by external pressure and those caused by internal pathological factors, achieving comprehensive physiological monitoring of the affected limb.

[0048] The control unit can comprehensively analyze data from three dimensions: pressure, temperature, and blood circulation, significantly improving the accuracy of alarms. For example:

[0049] Normal pressure but abnormal blood flow: This may indicate damage to the arterial intima or thrombosis, rather than external pressure.

[0050] Increased pressure accompanied by abnormal blood flow and temperature strongly suggests the occurrence of compartment syndrome.

[0051] This multi-parameter cross-validation enables the system to more intelligently and accurately determine the authenticity and severity of safety hazards, greatly reducing false alarms or missed alarms that may be caused by monitoring a single parameter.

[0052] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0053] Figure 1 This is a three-dimensional structural schematic diagram of the external fixation device for supracondylar fractures of the humerus in children according to the present invention;

[0054] Figure 2 for Figure 1 Enlarged view of a portion of point M in the middle;

[0055] Figure 3 for Figure 1 Axonometric view of the mid-arm;

[0056] Figure 4 for Figure 3 Sectional view along the AA direction;

[0057] Figure 5 for Figure 1 A schematic diagram of the internal structure of the middle plate.

[0058] The reference numerals in the accompanying drawings of the instruction manual include: 1. Crank arm; 2. Screw; 3. Clamping plate; 4. First knob; 101. Arc-shaped cylinder; 102. Clamping block; 103. Insert; 104. Nut block; 105. Threaded hole; 106. Worm gear; 107. Worm; 108. Slide groove; 109. Incomplete gear ring; 110. Clamping groove; 301. Second knob; 302. Lead screw; 303. Pressure pad; 304. Movable cavity; 305. Nut seat; 306. Cam block; 307. Rotating shaft; 308. Pulley; 309. Gear groove. Detailed Implementation

[0059] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] The following detailed description illustrates the specific implementation method:

[0063] Example:

[0064] As attached Figure 1 - Appendix Figure 5As shown: An external fixation device for supracondylar fracture of the humerus in children includes a main body of a fixation mechanism for physically restraining the fracture ends. Specifically, the main body of the fixation mechanism includes at least a pair of curved arms 1, each end of which is provided with an arc-shaped cylinder 101 that conforms to the patient's limb. Each arc-shaped cylinder 101 is provided with a binding mechanism for binding adjacent arc-shaped cylinders 101 to the patient's limb. Specifically, the binding mechanism includes clamping grooves 110 and clamping blocks 102 arranged on adjacent arc-shaped cylinders 101, combined with... Figure 1 As shown, the clamping groove 110 and the clamping block 102 are respectively arranged in the arc-shaped cylinder 101 located on different curved arms 1. When adjacent arc-shaped cylinders 101 are connected, the clamping block 102 slides with the clamping groove 110.

[0065] Combined with appendix Figure 2 As shown, an adjustment groove is provided in the clamping block 102, and a nut block 104 is slidably fitted in the adjustment groove. A threaded hole 105 is provided on the nut block 104.

[0066] Combined with appendix Figure 4 As shown, the clamping groove 110 is connected to the insertion port 103 on the side away from the limb, and the insertion port 103 is slidably fitted with a screw 2; when the clamping block 102 is slidably fitted with the clamping groove 110, the threaded hole 105 is threadedly fitted with the screw 2.

[0067] The main body of the fixation mechanism is equipped with an anti-rotation mechanism and a point-pressure mechanism. The anti-rotation mechanism is used to provide a pre-rotation clamping force to the distal humerus of the patient to counteract malunion. Preferably, the arc-shaped cylinder 101 near the patient's forearm is slidably connected to the bent arm 1. The anti-rotation mechanism includes a groove 108 opened in any one of the arc-shaped cylinders 101 near the patient's forearm, and an incomplete toothed ring 109 is welded and fixed in the groove 108; combined with the attached... Figure 1 and attached Figure 4 As shown, a first knob 4 is provided at one end of the crank arm 1 near the incomplete gear ring 109. The first knob 4 rotates with the crank arm 1. A worm 107 is coaxially welded to the first knob 4. The worm 107 meshes with a worm wheel 106. The worm wheel 106 is located inside the crank arm 1 and meshes with the incomplete gear ring 109.

[0068] The point pressure mechanism is used to provide corrective force at a preset position to maintain the Baumann angle.

[0069] Specifically, in conjunction with the appendix Figure 5As shown, the point pressure mechanism includes several clamping plates 3 circumferentially welded and fixed inside the arc-shaped cylinder 101. A movable cavity 304 is opened on the inner side of the clamping plate 3. Several pressure pads 303 are slidably connected to the movable cavity 304 near the patient's limb. Preferably, the pressure pads 303 are arranged in an array along the length of the clamping plate 3. A lead screw 302 and a rotating shaft 307 are rotatably connected inside the movable cavity 304. A nut seat 305 is threaded on the lead screw 302. A groove is opened on the nut seat 305 near the pressure pad 303. A cam block 306 is eccentrically arranged on the rotating shaft 307. The rotating shaft 307 and the cam block 306 are welded and fixed. The cam block 306 is slidably engaged with the side wall of the groove and the pressure pad 303 respectively.

[0070] The clamping plate 3 is rotatably fitted with a second knob 301 and a lever 308. The second knob 301 is coaxially welded and fixed to the lead screw 302. Preferably, the lever 308 is a disc structure with protruding teeth integrally provided on the outer side of the disc. The disc is coaxially splined and fixed to the rotating shaft 307.

[0071] Preferably, the clamping plate 3 is also provided with a limiting mechanism for restricting the rotation of the lever 308, in conjunction with the attached... Figure 5 As shown, the limiting mechanism includes a toothed groove 309 formed on the clamping plate 3. The pusher 308 and the rotating shaft 307 are slidably engaged by a spline. When the pusher 308 (protruding tooth) is inserted into the toothed groove 309, the pusher 308 and the toothed groove 309 are engaged.

[0072] Preferably, the clamping plate 3 is also provided with displacement scale marks and pressure scale marks; the displacement scale marks correspond to the displacement distance of the nut seat 305 in the movable cavity 304, and the displacement scale marks are engraved on the end of the clamping plate 3 near the second knob 301; the pressure scale marks correspond to the pressure between the cam block 306 and the pressure pad after the dial 308 rotates to a preset angle, and the pressure scale marks are engraved on the side of the clamping plate 3 near the dial 308.

[0073] Preferably, a pressure sensor is installed on the inner side of the splint 3. The pressure sensor is used to collect the pressure value between the splint 3 and the patient's limb. The pressure sensor is a flexible thin film pressure sensor. The pressure sensor is electrically connected to a display unit, which is used to display the pressure value.

[0074] Preferably, it also includes a control unit and an alarm notification unit; the control unit is used to control the operation of the alarm notification unit based on the pressure value; the alarm notification unit is used to send alarm notification signals to the outside. In this embodiment, the alarm notification unit integrates a buzzer, an LED light, and a wireless transmission chip.

[0075] Preferably, it also includes a temperature sensor and a blood flow sensor, which are located on the inner side of the splint 3 respectively; the temperature sensor is used to monitor the temperature of the patient's limb tissue; the blood flow sensor is used to monitor the blood supply to the patient's limb; the control unit is also used to control the operation of the alarm prompting unit based on the temperature and blood supply.

[0076] The specific implementation process is as follows:

[0077] First, the affected limb of the child is routinely disinfected and manually reduced to achieve preliminary anatomical alignment of the fracture ends.

[0078] Based on the child's arm circumference, the fixed circumference of the binding mechanism (the area enclosed by the arc-shaped cylinder 101 and the clamping block 102) is initially adjusted by pre-adjusting the position of the sliding nut block 104 in the adjustment groove.

[0079] Place the pair of curved arms 1 of the device on the outside of the affected limb, so that the arc-shaped cylinders 101 of the upper arm segment and the forearm segment respectively fit against the corresponding parts of the limb. Align the clamping blocks 102 of the adjacent arc-shaped cylinders 101 with the clamping grooves 110 and push them in to make them slide and fit, completing the initial docking.

[0080] Adjust the position of the nut block 104 so that the socket 103 coincides with the threaded hole 105. Pass the screw 2 through the socket 103 and screw it into the threaded hole 105 of the nut block 104. Tighten the screw 2 with a tool. The mechanical pressure will make the clamping block 102 fit tightly against the inner wall of the clamping groove 110, generating a huge static friction force, thereby firmly locking the entire curved arm 1 frame onto the child's limb.

[0081] Under C-arm fluoroscopy, observe whether there is rotational displacement of the distal fracture fragment.

[0082] If rotation is possible, the doctor can rotate the first knob 4. The first knob 4 drives the worm gear 107 to rotate, the worm gear 107 drives the meshing worm wheel 106 to rotate, and the worm wheel 106 then drives the incomplete gear ring 109 and the arc-shaped cylinder 101 in which it is located to rotate slightly and precisely relative to the curved arm 1.

[0083] This rotation directly alters the spatial posture of the forearm, thereby indirectly and non-invasively correcting rotational deformities at the distal end of the fracture. Due to the reverse self-locking characteristic of the worm gear 107 and worm wheel 106 system, once adjustment stops, the angle of the forearm is reliably locked, effectively counteracting rotational stress during daily activities.

[0084] Based on the Baumann angle determined by the X-ray, determine the location and direction where the corrective force needs to be applied.

[0085] Position adjustment: Rotate the second knob 301 to drive the lead screw 302 to rotate, which in turn drives the nut seat 305 to move linearly within the movable cavity 304. By observing the displacement scale marks on the clamping plate 3, the nut seat 305 and its groove can be precisely moved to the target position.

[0086] Pressure Adjustment: Gently pull the lever 308 outwards to disengage it from the toothed groove 309. Then rotate the lever 308, which drives the rotating shaft 307 and cam block 306 to rotate via the spline. The eccentric contour of the cam block 306 pushes the pressure pad 303 towards the limb, thereby applying orthopedic pressure. By observing the pressure scale markings on the splint 3, the pressure is precisely adjusted to the preset treatment window.

[0087] Locking: After adjustment, push the lever 308 back so that its protruding teeth can re-engage in the tooth groove 309 to achieve mechanical hard locking and prevent accidental changes in pressure.

[0088] After the device is installed and adjusted, the system enters a continuous monitoring state.

[0089] The pressure sensor monitors the contact pressure between the splint 3 and the limb in real time and transmits the data to the control unit.

[0090] Temperature and blood flow sensors continuously monitor the skin temperature and blood circulation at the distal end of the affected limb, and the data is also transmitted to the control unit.

[0091] The display unit shows the above physiological parameters in real time, allowing doctors and family members to view them intuitively.

[0092] The control unit compares the received pressure, temperature, and blood circulation data with internally preset safety thresholds. If any data exceeds the safety range (e.g., excessive pressure indicating a risk of compression, decreased temperature, and weakened blood circulation indicating a blood supply disorder), the control unit will immediately activate the alarm notification unit.

[0093] The alarm unit will sound an alarm through a buzzer and flash a red LED, depending on the urgency of the situation. It will also transmit the alarm information to the smart terminal of medical staff via a wireless transmission chip, enabling remote and real-time early warning and buying valuable time for intervention.

[0094] Follow-up and dynamic adjustment

[0095] If minor changes in fracture alignment are found during subsequent rehabilitation follow-up examinations via X-ray, the doctor will not need to remove the device.

[0096] The above steps can be repeated. By fine-tuning the first knob 4, the second knob 301 and the dial 308, the rotational deformity and Baumann angle can be recorrected non-invasively outside the body, truly achieving "dynamic correction in fixation" and avoiding additional trauma to the child caused by secondary repositioning.

[0097] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An external fixation device for supracondylar fracture of the humerus in children, comprising a main body of a fixation mechanism for physically restraining the fracture ends of the patient, characterized in that, The main body of the fixation mechanism is equipped with an anti-rotation mechanism and a point-pressure mechanism. The anti-rotation mechanism is used to provide a pre-rotation clamping force to the distal humerus of the patient to counteract malunion, and the point-pressure mechanism is used to provide orthopedic force at a preset position to maintain the Baumann angle.

2. The external fixation device for supracondylar fracture of the humerus in children according to claim 1, characterized in that, The main body of the fixation mechanism includes at least one pair of curved arms (1), and both ends of the curved arms (1) are provided with arc-shaped cylinders (101) that fit the patient's limbs. Each arc-shaped cylinder (101) is provided with a binding mechanism, which is used to bind the adjacent arc-shaped cylinders (101) to the patient's limbs.

3. The external fixation device for supracondylar fracture of the humerus in children according to claim 2, characterized in that, The binding mechanism includes a clamping groove (110) and a clamping block (102) arranged on adjacent arc-shaped cylinders (101). The clamping groove (110) and the clamping block (102) are respectively arranged in the arc-shaped cylinders (101) located on different curved arms (1). When adjacent arc-shaped cylinders (101) are connected, the clamping block (102) slides with the clamping groove (110). An adjustment groove is provided inside the clamping block (102), and a nut block (104) is slidably fitted inside the adjustment groove. A threaded hole (105) is provided on the nut block (104). The clamping groove (110) is connected to the socket (103) on the side away from the limb, and the socket (103) is slidably fitted with a screw (2); when the clamping block (102) is slidably fitted with the clamping groove (110), the threaded hole (105) is threadedly fitted with the screw (2).

4. The external fixation device for supracondylar fracture of the humerus in children according to claim 3, characterized in that, The arc-shaped cylinder (101) near the patient's forearm is slidably connected to the curved arm (1). The anti-rotation mechanism includes a groove (108) opened in any one of the arc-shaped cylinders (101) near the patient's forearm. An incomplete gear ring (109) is provided in the groove (108). A first knob (4) is provided at one end of the curved arm (1) near the incomplete gear ring (109). The first knob (4) is rotatably engaged with the curved arm (1). A worm (107) is coaxially provided on the first knob (4). The worm (107) meshes with a worm wheel (106). The worm wheel (106) meshes with the incomplete gear ring (109).

5. The external fixation device for supracondylar fracture of the humerus in children according to claim 4, characterized in that, The point pressure mechanism includes several clamping plates (3) circumferentially fixedly connected inside the arc-shaped cylinder (101). Each clamping plate (3) has a movable cavity (304) on its inner side. Several pressure pads (303) are slidably connected to the movable cavity (304) near the limb. A lead screw (302) and a rotating shaft (307) are rotatably connected inside the movable cavity (304). A nut seat (305) is threaded on the lead screw (302). A groove is opened on the side of the nut seat (305) near the pressure pad (303). A cam block (306) is eccentrically arranged on the rotating shaft (307). The cam block (306) is slidably engaged with the side wall of the groove and the pressure pad (303) respectively. The clamp (3) is fitted with a second knob (301) and a lever (308). The second knob (301) is coaxially fixedly connected to the lead screw (302), and the lever (308) is coaxially connected to the rotating shaft (307).

6. The external fixation device for supracondylar fracture of the humerus in children according to claim 5, characterized in that, The clamp (3) is also provided with a limiting mechanism for restricting the rotation of the lever (308). The limiting mechanism includes a toothed groove (309) opened on the clamp (3). The lever (308) is slidably engaged with the rotating shaft (307). When the lever (308) is inserted into the toothed groove (309), the lever (308) engages with the toothed groove (309).

7. The external fixation device for supracondylar fracture of the humerus in children according to claim 6, characterized in that, The clamp (3) is also provided with displacement scale marks and pressure scale marks; the displacement scale marks correspond to the displacement distance of the nut seat (305) in the movable cavity (304); the pressure scale marks correspond to the pressure between the cam block (306) and the pressure pad after the dial (308) rotates to a preset angle.

8. The external fixation device for supracondylar fracture of the humerus in children according to claim 7, characterized in that, Pressure sensors are provided on the inner side of the splint (3). The pressure sensors are used to collect the pressure value between the splint (3) and the patient's limb. The pressure sensors are electrically connected to a display unit, which is used to display the pressure value.

9. The external fixation device for supracondylar fracture of the humerus in children according to claim 8, characterized in that, It also includes a control unit and an alarm notification unit; the control unit is used to control the operation of the alarm notification unit based on the pressure value; the alarm notification unit is used to send alarm notification signals to the outside.

10. The external fixation device for supracondylar fracture of the humerus in children according to claim 9, characterized in that, It also includes a temperature sensor and a blood flow sensor; the temperature sensor is used to monitor the temperature of the patient's limb tissues; the blood flow sensor is used to monitor the blood supply to the patient's limbs; the control unit is also used to control the operation of the alarm unit based on the temperature and blood supply conditions.

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