Interlocking intramedullary nail capable of being applied to metaphyseal fracture bone defects

Abstract

The invention particularly relates to an interlocking intramedullary nail capable of being applied to metaphyseal fracture bone defects, and belongs to the field of medical instruments. The interlocking intramedullary nail comprises a main nail and locking screws, the main nail comprises a far end, a near end and an expansion part, and the far end and the expansion part are arranged at the two ends of the near end; a plurality of threaded grooves are formed in the two sides of the far end and the near end; and the locking screws are full-thread screws, and the locking screws are screwed in the thread grooves. According to the intramedullary nail, the locking screws and the threaded grooves in the periphery of the main nail are extruded and locked to be connected and fixed, the number of the used locking screws is large and can be twice that of common intramedullary nails, the locking screws are large in diameter, high in strength and not prone to breakage, the main nail is of a solid structure, the mechanical strength is higher than that of the common hollow intramedullary nails, and the main nail is not prone to breakage; therefore, the reliability and the stability of the metaphyseal fracture bone defects can be provided, the abnormal activity of the fracture end is eliminated, and fracture healing is facilitated.

Description

technical field [0001] The invention belongs to the technical field of medical devices, and in particular relates to an interlocking intramedullary nail applicable to metaphyseal fracture bone defects. Background technique [0002] Severe fractures of the long bones of the extremities are often accompanied by bone defects, and bone defects can also occur after resection of bone tumors and skeletal deformities. Therefore, clinical fractures and bone defects are more common, for which intramedullary nails and plate screws are the most effective surgical internal fixation methods. However, the steel plate is located on one side of the bone, which belongs to eccentric fixation, and it is easy to bend and break after longitudinal force, while the intramedullary nail is located in the center of the bone, which belongs to central fixation, and is not easy to bend and break after longitudinal force. Therefore, the mechanical effect of intramedullary nails is better than that of pla...

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Problems solved by technology

[0003] Most of the intramedullary nails currently used are hollow intramedullary nails. The advantage is that the guide wire with a smaller diameter can be used to guide the intramedullary nail into the medullary cavity, but the disadvantage is that the compressive and bending strength of the hollow intramedullary nail is lower than that of the solid marrow. Inner Nail

The locking screw holes of the currently used intramedullary nails are almost (99%) unthreaded, only application publication number: CN108433798A, application number: 2018103354383 The locking screw holes of the intramedullary nails are threaded, but the locking screw holes are located at the center of the main nail On the nail body, the strength of the intramedullary nail at the locking screw hole is weakened, and it is prone to breakage. The number of locking screws used in bone defects of metaphyseal fractures is limited

The length of the intramedullary nails currently used is fixed, and the intramedullary nails of different lengths are usually separated by 1cm. Sometimes there is no intramedullary nail of the right length during the operation. If the insertion is too long, the main nail is too short, and the proximal end of the main nail is buried in the In the medullary cavity, when the intramedullary nail is removed after the fracture heals, the proximal end of the main nail is embedded by callus. The tail of the main nail cannot be found or the callus growing into the tail affects the insertion and connection of the connector. If the main nail is too long, the main nail The tail protrudes under the skin at the opening of the bone, affecting the movement of the affected limb or causing pain, limitation of movement or other discomfort

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