CN201879816U - High-holding-force bone screw - Google Patents

Abstract

The utility model relates to a bone screw, in particular to a high-holding-force bone screw which is characterized in that screw threads on a screw rod are gradually thickened from the front end to the rear end of the screw rod. Since the screw threads on the bone screw are thickened turns after turns from the front end to the rear end of the bone screw, extrusion force of any two adjacent turns of threads, which is exerted onto the human bone tissue between the two turns of threads, is strengthened from the front end to the rear end of the screw rod along the axial direction of the screw rod when the bone screw is screwed into a bone of a human body. Decrease of the extrusion force between the inner screw threads formed on the bone of the human body and the outer screw threads of the screw rod can be avoided, and the decrease of the extrusion force is caused by abrasion of the inner screw threads. Simultaneously, the holding force (binding force) between the inner screw threads formed on the bone of the human body and the outer screw threads of the screw rod is intensified, thereby loosening, automatic dropping out and even failure mode caused by external force can be completely avoided.

Description

A kind of high hold bone screw

Technical field

This utility model is a kind of bone screw that is applied to medical industry orthopaedics consumptive material field, can be divided into bone screw that is used for human fracture position body internal fixation and the pedicle screw two big classes that are used for spinal column position body internal fixation, be specially adapted to osteoporotic bone injury patient.

Background technology

As everyone knows, screw is widely used in every field such as production, life as a kind of securing member, screw is made up of head of screw and shank of screw two parts, rounded or the hexagon of head of screw, when head of screw was rounded, its end face was provided with " one " font, " ten " font or " interior hexagonal " shape application of force groove, and shank of screw is connected with head of screw, shank of screw is provided with the thread that thread form is identical, pitch equates, the target that this screw is suitable for generally is inflexible metal.The bone screw that is used for medical industry orthopaedics consumptive material field at present also is the above-mentioned industrial screw designs of reference, promptly skeleton is equal to rigid material (as metal material) design, and skeleton has easy to wear and can produce the material behavior of strain under certain external force effect within the specific limits, has tangible different qualities with rigid material, therefore present bone screw is when carrying out the body internal fixation to human fracture position or spinal column position, a kind of comparatively common failure pattern is arranged, that is: bone screw in skeleton, be detained just take place after a period of time loosening, withdraw from voluntarily, even the situation of being extracted by external force, trace it to its cause, mainly being present this bone screw is all the rigid material design to skeleton etc., and do not consider that skeleton is easy to wear and under certain external force effect, can produce the material behavior of strain within the specific limits, when bone screw screws in skeleton, the initial segment of the female thread thread on the skeleton, owing to the screw-in through multiple tracks thread on the bone screw bar causes female thread thread that wearing and tearing make initial segment and the mutual extrusion power between the external screw thread thread on the bone screw bar to diminish to have reduced hold (adhesion) between bone screw and the skeleton, can take place to become flexible after a period of time thereby cause bone screw in skeleton, to be detained, withdraw from voluntarily, even the phenomenon of being extracted by external force and the causing failure of performing the operation.

Summary of the invention

This utility model proposes a kind of high hold (high-bond) screw that is applicable to skeleton (particularly sufferers of osteoporosis face skeleton) at hold (adhesion) deficiency that present medical industry orthopaedics consumptive material field bone screw exists.

This utility model can reach by following measure:

A kind of high hold (high-bond) bone screw comprises head of screw and shank of screw two parts, and the rear end of shank of screw is connected with head of screw, it is characterized in that keeping on the shank of screw thread pitch constant, and the thread tooth is thick to be increased from shank of screw front end to shank of screw rear end from coil to coil.

Use bone screw of the present utility model because the tooth of shank of screw thread is thick in the end from coil to coil thickening backward of screw front end, just make bone screw after screwing in skeleton, shank of screw organizes from coil to coil to strengthen extruding force along two adjacent rings thread on the shank of screw axis direction to the skeleton between the two circle threads from front end to the back-end, when having offset extruding force between that the female thread thread that forms on the skeleton brings because of wearing and tearing and the shank of screw external screw thread thread and having reduced, increase on the shank of screw hold (adhesion) between the female thread thread on the external screw thread thread and skeleton, thereby thoroughly avoided the loosening of existing screw, withdraw from voluntarily, even extracted below in conjunction with accompanying drawing by external force this utility model is further described.

Description of drawings

Fig. 1 is the structural representation of the bone screw of application prior art.

Fig. 2 is the structural representation of the pedicle screw of application prior art.

Fig. 3 is the structural representation of the bone screw of application the art of this patent.

Fig. 4 is a vertebral pedicle bolt structure sketch map of using the art of this patent.

The specific embodiment

Below in conjunction with accompanying drawing this utility model is further described:

A kind of high hold (high-bond) bone screw (dividing bone screw and pedicle screw two big classes), comprise head of screw 1 and shank of screw 2 two parts, the rear end of shank of screw 2 is connected with head of screw 1, and the pitch of thread 3 keeps P to remain unchanged on the shank of screw 2, and is above-mentioned same as the prior art.

The thick T of tooth of the thread on the bone screw shank of screw 23 that is characterised in that of the present utility model thickeies from shank of screw 2 front ends to rear end from coil to coil, because screw thread tooth is thick in the from coil to coil thickening to the back-end of screw front end, just make bone screw after screwing in skeleton, shank of screw organizes from coil to coil to strengthen extruding force to the rear end along any two adjacent rings thread on the shank of screw axis direction to the skeleton between the two circle threads from front end, when having offset extruding force between that the female thread thread that forms on the skeleton brings because of wearing and tearing and the shank of screw external screw thread thread and having reduced, increase the hold (adhesion) between the female thread thread that forms on the external screw thread thread and skeleton on the shank of screw, thereby thoroughly avoided the loosening of existing screw, withdraw from voluntarily, even the failure mode of being extracted by external force occurs.

Claims (1)

1. one kind high hold bone screw comprises head of screw and shank of screw, and the rear end of shank of screw is connected with head of screw, it is characterized in that thread pitch remains unchanged on the shank of screw, and screw thread thread tooth is thick to be thickeied gradually by shank of screw front end to shank of screw rear end.

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