CN2829653Y

CN2829653Y - Herniation proof internally fixed bone screw

Info

Publication number: CN2829653Y
Application number: CN 200520084538
Authority: CN
Inventors: 李浩淼
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-06-22
Filing date: 2005-06-22
Publication date: 2006-10-25
Anticipated expiration: 2015-06-22

Abstract

The utility model relates to a herniation preventing internal fixed bone screw which belongs to an appliance for fixing a skeleton of orthopaedics for clinical medical application. The utility model comprises a tubular outer sleeve and a rod-shaped inner core which is sheathed in the tubular outer sleeve, wherein the front end of the tubular outer sleeve is provided with an axial incision; the outer diameter of the front end of the rod-shaped inner core is gradually increased to form an expansion joint; the outer diameter of other parts of the rod-shaped inner core is slightly less than the inner diameter of the tubular outer sleeve; by using the herniation preventing internal fixed bone screw of the utility model, because the end part is provided with the expansion joint to properly stabilize expansion, holding force for the skeleton is increased and the occurrence of the herniation phenomenon of the screw is reduced and prevented.

Description

Prevent deviating from the solid bone screw of internal fixation

Technical field

This utility model belongs to the utensil of clinical medical orthopaedics fix bone, relates in particular to a kind of solid bone screw.

Background technology

Utilizing screw to carry out the bone internal fixation is the technical method that is widely used in the clinical medicine bone surgery in world today's scope.Present solid bone screw and normal wood bolt structure are basic identical, it comprises the portion of screwing of major part, the thin rod part that has tapping screw thread that is connected with its one, the termination of thin bar is most advanced and sophisticated, during use, on the correct position of bone, get out blind hole with awl or drill bit earlier earlier, be screwed into solid bone screw then, pass the through hole of steel plate with consolidating the bone screw stem, fastening with solid bone screw.In addition, also there is the stem of some solid bone screw not have tapping screw thread.

The solid bone screw of this structure is owing to only depend on the frictional force of interference fit or tapping screw thread to cooperate the hold that produces to be connected with bone, therefore after being screwed into skeleton, be very easy to become flexible even deviate from, cause the reason of this phenomenon have following some: 1. the skeleton overwhelming majority of a lot of privileged sites of human body such as vertebrae, neck of femur is made of spongy bone, this sclerotin is soft relatively, and is relatively poor to the hold of screw.Particularly serious in this on one's body phenomenon of osteoporotic patient; 2. being screwed in the operation needs before the screw open a tunnel with awl or drill bit earlier on the correct position of bone, and this tends to run into because of going into to follow closely that point location is inaccurate causes holing repeatedly, causes following closely that diameter is excessive, screw contacts not tight with sclerotin on every side after being screwed into.This problem is outstanding especially on one's body to carry out repeatedly the patient of revision procedure behind an operative failure; 3. often need to utilize the screw that is screwed into skeleton that monoblock bone is lifted in the operation and reset, as be used for the pedicle nail of lumbar spondylolisthesis and be used for the orthopedic vertebral body nail of scoliosis; Or by screw to adding press fit between the bone piece, as be used for the lag screw of fracture of femoral neck.This power that lifts or pressurize is big and continue existence, and this is to the baptism of screw to the hold of skeleton; 4. patients after surgery motion also can increase the stressed of screw as the interior receipts abduction of bending and stretching with hip joint of vertebra, makes its easier getting loose.

The consequence that the defective that the solid bone screw of this structure gets loose easily causes is: 1. current for reducing getting loose of solid bone screw, the methods that adopt the bed rest time that prolongs patient more.So not only increased patient's misery and hospitalization cost, and may cause severe complications, as lower limb venous thrombosis, pulmonary and urinary system infection, osteoporosis or the like; 2. because getting loose of screw causes operative failure, carry out twice even the patient of revision procedure repeatedly,, also increase operation risk, as iatrogenic fracture, nerve injury or the like except being multiplied of ailing and medical expense.

Summary of the invention

This utility model main purpose is in order to overcome above-mentioned defective, provide a kind of lock skeleton prevent deviating from the solid bone screw of internal fixation.

This utility model comprises jacket tube and cover shaft-like inner core therein, and the front end of jacket tube is provided with axial cut-outs, and the front end external diameter of shaft-like inner core increases the formation expansion joint gradually, and the other parts external diameter of shaft-like inner core is more smaller than jacket tube internal diameter.

Above-mentioned shaft-like inner core etc. outer radius portion external screw thread is set; The tail end of jacket tube is provided with the nut that is fixed as one, and the bottom of nut has setting-up piece; The tail end of shaft-like inner core can pass this nut; The jacket tube outer peripheral face is provided with self tapping or non-tapping screw thread.

The front end otch of above-mentioned overcoat can have 2-4, and at the circumferencial direction uniform distribution; The expansion joint of shaft-like inner core front end is a frustum.

When above-mentioned shaft-like inner core inserts and strains from the front end of jacket tube is retrograde, the expansion joint of shaft-like inner core front end just is the umbrella appropriateness with the end of overcoat and struts, sclerotin around controlling firmly, and can draw tighter and tighter, thus overcome the defective that existing solid bone screw easily gets loose preferably.

Adopt and of the present utility modelly prevent deviating from the solid bone screw of internal fixation, the expansion joint appropriateness is stable to expand because the end is provided with, and has increased hold to skeleton, reduces and prevented the get loose generation of phenomenon of screw.

Description of drawings

Fig. 1 is this utility model overall structure sketch map;

Fig. 2 is this utility model jacket tube structural representation;

Fig. 3 is the cutaway view along A-A shown in Figure 2;

Fig. 4 is the shaft-like core arrangement sketch map of this utility model;

Fig. 5 is this utility model user mode sketch map.

The specific embodiment

As shown in Figure 1, this utility model comprises jacket tube 10 and cover shaft-like inner core 20 therein, the front end of jacket tube 10 is provided with axial cut-outs 11, the front end external diameter of shaft-like inner core 20 increases gradually and forms expansion joint 21, and expansion joint 21 is decreased to shaft-like inner core 20 tail ends isometrical after external diameter increases to a certain degree again gradually; The other parts external diameter of shaft-like inner core 20 is more smaller than jacket tube 10 internal diameters; Shaft-like inner core 20 etc. outer radius portion external screw thread 22 is set; Shown in Fig. 2,3, the nut 12 that the tail end of jacket tube 10 is fixed as one, the bottom setting-up piece 13 of nut 12; The tail end of shaft-like inner core 20 can pass this nut 12; Jacket tube 10 outer peripheral faces are provided with self tapping or non-tapping screw thread 14.

Above-mentioned otch 11 can have 2-4, and at the circumferencial direction uniform distribution; As shown in Figure 4, expansion joint 21 is a frustum, and its shape had both satisfied the needs of the locking of expanding, and makes the basic identical of the external shape of preventing deviating from when the solid bone screw of internal fixation is used and prior art again.

Be that example illustrates using method of the present utility model and step below with the pedicle of vertebral arch:

(1) shaft-like inner core 20 is inserted from the front end of jacket tube 10 is retrograde, and the tail end that a nut 30 exposes jacket tube 10 from shaft-like inner core 20 loaded onto slightly tighten, shaft-like inner core 20 can not rocked in jacket tube 10, but the front end of jacket tube 10 is not strutted at this moment.

The vertebra rear of (2) following closely on need is determined into the nail point, goes into the nail point certainly by narrow bone structure with bone awl or drill bit then---it is interior to appropriate depth that pedicle of vertebral arch is slowly shot vertebral body, forms blind hole (as the uncertain available depth finder of the degree of depth fathoms after shooting);

(3) blind hole on the skeleton 50 is carried out tapping; As use jacket tube 10 band thread tappings prevent deviate from the solid bone screw of internal fixation, this step is omitted;

(4) nut 30 with shaft-like inner core tail end takes off, and the shaft-like inner core 20 that suitable steel plate 40 is enclosed within two or more bone screws exposes the part (in order to connect steadily, can overlap a pad below steel plate sometimes) of jacket tube 10;

(5) use the nail sleeve and entangle nut 12, preventing of assembling of step (1) deviate from the solid bone screw of internal fixation in blind hole slowly is screwed into blind hole on the skeleton 50, until tightening; Because the bottom of nut 12 is fixed with pad 13, prevented to screw to prevent deviating from and gone up the slippage of nail sleeve in the solid bone screw process of internal fixation and run on the skeleton 50, say that therefore pad 13 has the effect of protection skeleton 50;

(6) the both sides pedicle of vertebral arch of a plurality of vertebras of following closely on need of repeating step (1) to (4) is screwed on respectively and is prevented deviating from the solid bone screw of internal fixation;

(7) nut 30 is loaded onto from shaft-like inner core 20 tail ends again, with locking sleeve nut 30 is tightened gradually, as shown in Figure 5, shaft-like inner core 20 just upwards slides along the inwall of jacket tube 10 gradually, so just being umbrella with the front end of jacket tube 10, the expansion joint 21 of shaft-like inner core 20 front ends struts, and can draw tighter and tighter, sclerotin around controlling firmly, and make and prevent deviating from the solid bone screw of internal fixation and 40 of steel plates fixedly secure, the front end of overcoat is fully expanded, strut, can also increase a nut again in order to prevent that nut 30 from getting loose;

(8) cut off the afterbody of unnecessary shaft-like inner core 20.

Be the step of removing steel plate 40 and preventing deviating from the solid bone screw of internal fixation below:

(1) takes off the nut 30 of shaft-like inner core 20 tail ends;

(2) take off steel plate 40;

(3) push the tail end of shaft-like inner core 20 gently forward, the shaft-like inner core 20 of tension is backward unclamped, so just can make into the front end gathering of the open jacket tube 10 of umbrella;

(4) use the nail sleeve and entangle nut 12, reverse rotation is taken out jacket tube 10 from the skeleton blind hole then, more shaft-like inner core 20 is taken out.

From the above, of the present utility modelly prevent deviating from the solid bone screw of internal fixation and increased hold, reduce and prevented the get loose generation of phenomenon of screw skeleton.

The foregoing description is at pedicle of vertebral arch, situation for cone fracture synthetism and spongy bone, operating procedure is basic identical, in the practice, can be according to the kind difference of need synthetism bone, and make operating procedure slightly different, need first steel plate to be placed on the correct position of bone surface during as the fracture of the tibial plateau synthetism, begin operation from step 1 again, and omit step 5.

In a word, of the present utility modelly prevent deviating from the solid bone screw of internal fixation and increased hold, reduce and prevented the get loose generation of phenomenon of screw skeleton.

Claims

1. prevent deviating from the solid bone screw of internal fixation for one kind, it is characterized in that it comprises jacket tube and cover shaft-like inner core therein, the front end of jacket tube is provided with axial cut-outs, the front end external diameter of shaft-like inner core increases the formation expansion joint gradually, and the other parts external diameter of shaft-like inner core is more smaller than jacket tube internal diameter.

2. according to claim 1ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that described otch has 2-4, and at the circumferencial direction uniform distribution.

3. according to claim 2ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the equal-diameter part of shaft-like inner core is provided with external screw thread.

4. according to claim 1ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the expansion joint of shaft-like inner core is a frustum.

5. according to claim 1ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the tail end of jacket tube is provided with hold-doun nut, the rear end of shaft-like inner core passes this nut.

6. according to claim 5ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that described nut and jacket tube are one.

7. according to claim 5ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the bottom setting-up piece of nut.

8. according to claim 1ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the jacket tube outer peripheral face is provided with tapping screw thread.

9. according to claim 1ly prevent deviating from the solid bone screw of internal fixation, it is characterized in that the jacket tube outer peripheral face is provided with non-tapping screw thread.