Detachable rivet for internal fixation of mandible

Abstract

The invention discloses a detachable rivet for internal fixation of mandible. The rivet comprises a rivet body and a rod-shaped rivet core penetrating through the rivet body; the rivet core is dividedinto a core pulling rod and an inner core rod by a fracture groove arranged in the middle of the rivet core, the surface of the inner core rod close to the left end is provided with a straight knurling, and a raised head is arranged at the right end of the inner core rod; the rivet body comprises a round pipe, a truncated cone-shaped extension is arranged on the surface of the round pipe close tothe left end, a lantern-shaped expansion mechanism consisting of leaf-shaped strips with transverse sawteeth on the surface is arranged at the right end of the round pipe, the right end of the expansion mechanism is connected with the right end of the inner core rod and the raised head, a snap ring is further arranged at the left end of the round pipe, and the diameter of the straight knurling is0.05-0.15 mm larger than the inner diameter of the round pipe. The detachable rivet provided by the invention has the advantages that the operation time is greatly reduced, the operation difficulty is reduced, the mounting and fixing are efficient and quick, the detachable rivet is reliable and safe as a fastener of an internal fixing system, the anti-pull-out force of a screw is improved, and the possibility of loosening and falling of the screw is reduced.

Description

technical field [0001] The invention belongs to the field of medical instruments, and in particular relates to a detachable rivet for internal fixation of mandible. Background technique [0002] In the internal fixation of the mandible, most of the current devices use small lag screws and small internal fixation plates. The internal fixation of the mandible is different from other bones in the human body. The mandible is a high-stress bone, and the small internal fixation plate The width determines the upper limit of the screw diameter, and the insufficient friction and pull-out resistance between lag screws with smaller diameter and bone will often lead to loosening and falling off of the screw, and eventually cause internal fixation failure. Due to the small bone thickness of the mandible, there is also a way to pass the screw through the contralateral cortical bone during the operation to enhance the anti-extraction force of the screw, but the screw length is too long may...

AI Technical Summary

Problems solved by technology

[0002] In the internal fixation of the mandible, most of the current devices use small lag screws and small internal fixation plates. The internal fixation of the mandible is different from other bones in the human body. The mandible is a high-stress bone, and the small internal fixation plate The width determines the upper limit of the screw diameter, and the insufficient friction and pull-out resistance between lag screws with smaller diameters and bone will often lead to loosening and falling off of the screw, and eventually cause internal fixation failure

Due to the small bone thickness of the mandible, there is also a way to pass the screw through the contralateral cortical bone during the operation to enhance the anti-extraction force of the screw, and the screw length is too long may damage the inner mandibular nerve and the contralateral soft tissue

At the same time, the cumbersome operations required for existing surgical operations, such as drilling, tapping, depth measurement, treatment of nail channels, and screw screwing, make patients more susceptible to infection

[0003] There are also some patents related to detachable bone rivets. These patented technologies adopt the inner and outer tube structure design, which will cause the thickness of the inner and outer tube heads exposed to the bone surface to be too large, which does not meet the thickness requirements of the mandibular internal fixation plate.

Moreover, the existing detachable bone rivets are made by punching the bone into a through hole for riveting, which is easy to injure the soft tissue on the opposite side of the mandible, and even the mental nerve and inferior alveolar nerve in the mandible.

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