SU1637774A1 - Appliance for femoral extension - Google Patents

Abstract

The hip extension device is designed to shorten the bone elongation time. The device comprises an outer hollow body 1 with a lid 2 fixed on one end, in the side wall of which a hole 3 is made. In the outer body 1 there is an inner hollow body 4 having a possibility of longitudinal movement. Cases 1 and 4 are interconnected. A fixing screw 11 is mounted on the free end of the inner body 4. Intermediate hollow body 12 is aligned between the bodies 1 and 4. A screw 18 is installed in the outer body 1 to prevent the outer body 1 from turning relative to the proximal femur. At the open end of the intermediate casing 12, ribs and a sleeve are installed, by means of which the intermediate casing 12 is fastened to the middle part of the femur, bounded by two osteotomies. 6 Il.

Description

The invention relates to medical technology, namely to traumatology and orthopedics.

The purpose of the invention is to shorten the bone elongation time.

FIG. 1 shows a device for lengthening a femur mounted in the femur; figure 2 - the device, a longitudinal section; on fig.Z - section aa in figure 2; figure 4 - section bb in figure 2; Fig, 5 is a section bb In figure 2; figure 6 - section GG in figure 2.

The device comprises an outer hollow body 1 with a lid 2 fixed on one end, in the side wall of which an opening 3 is made. In the outer body 1 there is an inner hollow body 4 having a possibility of longitudinal movement. Cases 1,4 are interconnected

adjustment unit 5, made in the form of a lead screw 6, a lever 7 located in the opening 3 by the roof 2, and also a worm gear pair 8, a worm to 9 of which is connected with the lever 7, and a worm wheel 10 is connected with a lead screw 6, threaded connection with the inner case 4, on the free end of which a bone lock is installed, made in the form of a screw 11. Between the outer and inner cases t, 4 there is an intermediate hollow body 12 coaxial with the latter and connected with a threaded connection with the lead screw 6. When this lead screw 6 is made two-step nchatym, wherein the diameter of the thread portion of the lead screw 6 cooperating with the inner housing 4, the diameter of the screw shaft portion 6, cooperating with the intermediate housing 12, and

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the thread pitch made in the section of the lead screw 6 of a larger diameter exceeds the step of the thread made in the section of the screw screw 6 of a smaller diameter twice. The outer and intermediate housings 1, 12 have longitudinal guide grooves 13, 14, in which the projections 15, 16 of the intermediate and inner housings 12, 4 are placed. The housing 4 at the free end is provided with a hole 17 for screw 11. A screw is installed in the outer housing 1 18. A lever 19 is connected with the lever 7 by means of a hinge 20. Moreover, the lever 7 interacts with the screw 9 through the opening 3 in the cover 2. The surfaces of the lever 7 and the handle 19 are covered with a thin-walled elastic cover 21, fixed with a neck to the cover 2. On the screw 6 has an abutment 22 limiting the displacement lead screw 6 in the longitudinal direction. At the open end of the intermediate body 12 there are grooves 23, in which ribs 24 are mounted for removal, the sharp edges of which protrude above the surface of the intermediate body 12.

The device works as follows.

If it is necessary to lengthen the femur, access to the large skewer is performed as usual. A channel is drilled for the instrument through the large skewer and the bone-brain canal. Moreover, the channel width is different in length, so in the distal part it should be equal to the diameter of the housing 4, above the level of the alleged distal osteotomy 25 equal to the diameter of the housing 12, and from the level of the distal end of the housing 1 - to the diameter of the housing 1. This is achieved using drills of various diameters and easily since the device knows the relative position of the distal ends of the bodies 1,4, 12. The distal osteotomy is performed so that after the device is inserted between the distal end of the body 12 and the distal edge of the segment 26, the bone remains for the sleeve 27, which has an orifice diameter equal to the outer diameter of the housing 4, and has a thread from the outer surface, the turns of which should protrude above the surface of the housing 12. The device is guided into the formed channel through a large spit. Then, ribs 24 are punched into the grooves 23 from the side of osteotomy 25, which with sharp edges cut into the bone tissue of the bone segment 26 and prevent rotational rotation of the housing 12. Then, the sleeve 27 is screwed into the channel of the segment 26 above the distal end of the housing 12. Sleeve 27 serves as a stop

for body 12. The distal end of body 4 conducts the e channel of the bone segment 28 and is fixed with a screw 11, which passes through the bone tissue into the hole 17 of body 4.

Suture the incision above the osteotomy 25 and access to the target line of the superior osteotomy 29. The bone is crossed around the distractor. A screw 18 is led through the fabric of segment 30 and screwed into the socket in the side surface of the housing 1. The lid 9 is located above the large skewer. Lever 7 with knob 19 is located above the large skewer. Lever 7 with handle 19 located under

5 with a cover 21, a stalk is formed into a stalk formed from the skin of the lateral surface of the thigh. The hinge 20 allows the handle 19 to be pressed against the thigh surface, which eliminates the injury of the skin stem. For

0 this, while holding the handle 19 perpendicular to the lever 7, rotates it 90 to 180 °. Lever 7 rotates the worm to 9 and through the worm wheel 10 spindle screw 6. When the spindle screw 6 rotates, body 12

5 is unscrewed from its proximal part and advances along it. Due to the fact that the thread pitch of the distal part of the lead screw 6 is larger (it is usually advisable that the thread pitch of the distal portion of the screw 6 be

0 more than the pitch of the thread of the proximal section of the lead screw twice) the pitch of the thread of the proximal part of the screw 6, the screw 6 is unscrewed from the housing 4, and at a speed twice as large as the housing 12, which ensures the extension of the housing 12, 4, and consequently, the divergence of bone fragments 26, 28.30. The bone segments are extended in each osteotomy by 1.5-2 mm per day and

0, the required degree of distraction by several rotations of the lever 7. When the dermal stem turns 90–180 °, it is not injured. After turning the knob 19 sets the axis of the lever 7, thanks

5, the elastic cover 21, the skin stem, returns to its original position. After the required degree of bone distraction has been achieved, the device works as an intraosseous fixative until the segments consolidate.

0 To remove the device, remove the screws 11, 18, expose the cover 2 and remove the device from the bone channel. At the same time, the sleeve 27 and the ribs 24 remain in the medullary canal.

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When working with the proposed distractor, it is possible to extend the femur at a speed twice as high as when working with a known apparatus.

Claims (1)

Invention Formula A device for lengthening the femur, comprising an outer hollow body with a lid fixed at one end, in the side wall of which a hole is made, and an inner hollow body having the possibility of longitudinal movement, the housings are interconnected by an adjusting unit made in the form of a lead screw, a lever, located in the hole of the lid, as well as a worm gear pair, the worm to which is connected with the lever, and the worm gear with the lead screw connected by a threaded connection with the inner case, at the free end of which flax a bone fixator, characterized in that, in order to reduce the bone elongation time, the device is provided with an intermediate hollow body coaxially with outer and inner housings and associated threaded connection with the lead screw, the latter being two-stage, with the diameter of the thread of the screw section interacting with 0 the inner case exceeds the diameter of the section of the screw interacting with the intermediate case, and the pitch of the thread made on the section of the screw of a larger diameter exceeds the pitch of the thread made on the section of the screw of a smaller diameter by two rags. Fig FIG. 2 Fig.z FIG L 5 23 FIG. b