CN86209722U - Pressure nail with threaded ends and its auxiliary appliances used for the treatment of thighbone and cervical vertebra fracture - Google Patents

Abstract

The utility model provides a novel pressure nail with double threads, which is used for treating a femoral neck fracture. The utility model is characterized in that the utility model adopts a differential thread for pressurization, and the pressure can reach 16 kg, which is good for the union of a fracture; the thread pitch of a thread at the front end is long, a thread tooth is high and thin, and the thread at the front end can not easily slide out of a femoral head; the tail part adopts a double-line thread, which reduces the pressure for a cortical bone and increases the stretching resistance and the stability; threads at the front and the back are respectively provided with a cutter edge, and a self-tapping screw is formed. The utility model has the advantages of few apparatuses which are required, and simple operation. The utility model is also provided with auxiliary implements, such as a special screw back and forth device, etc. When the nail enters a bone, the swing can be avoided. The auxiliary implement can also prevent the nail from being loosened in the femoral head.

Description

Pressure nail with threaded ends and its auxiliary appliances used for the treatment of thighbone and cervical vertebra fracture

This utility model belongs to the improvement of treatment fracture of femoral neck apparatus.

Fracture of femoral neck is the common and severe traumatic of old people, because of its position of living in dissect structural specially, belongs to incurable disease in the past in this century, and patient just has to the years of residue are all consumed on bedding and wheelchair.The beginning of this century American Luo Yaer.Hitman (R.Whitman) has found the method that resets, and just just 23% patient has obtained hope, up to nineteen twenty-five Smith.Peter gloomy (Smith-Peteisen) has invented three flanged nail, make the healing rate of fracture bring up to 70～80% rapidly, though but multiple internal fixation form after this occurred, the pressurization nail appearred again after the sixties, but it is because not enough to the biomethanics structure understanding of neck of femur, all also there are various shortcomings, so the union of fracture rate improves not quite.The main internal fixation method that uses has following several at present:

(1) three flanged nail is fixed.This is the method that also generally adopts both at home and abroad at present.Its fixation principle is to utilize the neck of femur two folding end serial connection embeddings after three flanged nail will reset tight.Its concrete operations step is first appropriate location under femoral bone tuberosity, digs out a small bone hole, then with the guide pin location satisfied after, with three flanged nail along guide pin squeeze into and embedding tight.Its shortcoming mainly contains 3 α because hammering enters, easy damaged femoral head and supply vessels, and the neck of femur necrosis rate is on average up to 20～35%; The easy slippage of b and lose fixation; C is because of no axial compressive force, so healing is slower.

(2) the spring compression screw fixation is fixed.Last Mecutchen J.W of (C-linical oithopaties and related reseaich) 171 phases nineteen eighty-two " clinical rectification and correlational study " etc. introduces a kind of spring compression screw fixation.Its pressurization principle is that the drive screw that utilizes the spring leaf disrotatory after the mechanical compress to go in the femoral head produces a pulling force, and the fracture face is pressurizeed.This nail has two shortcoming α screw afterbodys too big, is unfavorable for early ambulant; The elastic force that the b spring leaf produces can not coaxially act on the pulling force of drive screw.

(3) the spring washer compression screw fixation is fixed.This is developed in nineteen eighty-three by Shanghai Huashan Hospital and Surgical Instruments No.6 Factory, Shanghai.Its screw sizes is: length 90mm～115mm6 kind, and front threads is M11 * 3, depth of threat 2mm, saw shape tooth, 25 ° of angle of threads, tailing screw flight are M11 * 1.Its fixation principle is after front threads screws in femoral head, and with nut holddown spring packing ring, spring washer makes elastic force coaxial with the direction of drive screw pulling force, and fracture segment is drawn close mutually by the corner bracket on the carried interest bone outside cortical bone, reaches the effect of pressure fixing.Its operating procedure is at first to locate with guide pin, after the satisfaction, twists out a through capital hole with reamer along guide pin, attacks a screwed hole again at the cortical bone place, and drive screw is screwed in handgrip along guide pin, fixes with nut holddown spring circle at last.It is little that this method mainly contains its front threads pitch of two shortcoming α, transverse tooth thickness, so damage sclerotin tissue is many, stretching resistance is little; B institute is all supported by corner bracket effectively, because corner bracket and cortical bone contact area are little, pressure is big, makes solid failure because of the damage of the cortical bone on the supporting surface easily.

The purpose of this utility model provides a kind of healing rate of fracture of femoral neck that can make and improves safe and reliable, easy to operation new fixed apparatus.

This utility model adopts is a kind of double thread pressurization nail that utilizes the screw thread differential principle that the fracture end of fracture of femoral neck is pressurizeed.Screw shown in figure one, its length are that 75mm～110mm does not wait, front threads length 25mm, external diameter 10mm, pitch 5mm, 10 °～15 ° of angle of threads, its front end has a pair of symmetric cutting edge, and this cutting edge anterior angle is 2 °～3 °, and relief angle is 15 °～30 °.Tailing screw flight is a double thread, major diameter of thread 12mm, and 60 ° of angle of threads, pitch 4mm, the centre is a polished rod, directly is 6mm at the bottom of its diameter and the front threads.Between polished rod and tailing screw flight, one section garden conical surface transition is arranged, there is the through hole of a φ 3 at the screw center, is convenient to insert guide pin, has-M at nail tail center ₆Inner bolt hole.Tail end face has a cross recess, is convenient to connect with the advance and retreat device.For precession, take out nail, specialized designs one cover apparatus such as figure two, this cover apparatus is by drill bit (1), advance and retreat device (2) and holder are formed (3).Bit diameter is 10mm, and there is the sharp head of a long 5mm front portion, and afterbody has cross recess.Advance and retreat device head has the cross projection, and there is the hanging screw of a hollow (aperture 3mm) centre, makes drill bit or screw can firmly be connected into one.Holder is enclosed within advance and retreat device afterbody to head hollow, becomes to be slidingly connected with it.Holder is the rear portion one arc pallet, is butted on the operator abdominal part during operation and keeps stable, increases thrust.The fixation principle of this screw is: after anterior screw thread revolved the femoral neck bone broken line and enters femoral head, because the preceding garden of the tailing screw flight conical surface props up cortical bone, the two ends of fracture of femoral neck are drawn close, when treating that tailing screw flight enters femoral cortex, because two ends thread pitch difference, the rotation back produces differential, make fracture end obtain the compression, treat that afterbody all enters cortical bone after, through biological mechanics determining, pressurization reaches 16kg, thereby can promote the healing of fracturing.Neck of femur has constituted the mechanical structure of a reinforcement with pressurization nail, can improve the bending resistance of neck of femur, and its fracture two ends can be born the pressure of 80kg after measured, and it is nearly 50% to recover physiological function, is convenient to early ambulant.Operating process is: at the femur mid point of the side of falling 25mm～30mm slightly, with advance and retreat device with the deep cortex of bit drills, insert guide pin, after the position is satisfied, with the advance and retreat device screw that is of convenient length is enclosed within on the guide pin and screws in the femoral head, till the tailing screw flight of screw all enters cortical bone securely, after after the fixing satisfaction of X-ray confirmation screw, sew up the incision.

Compared with the prior art, this utility model has following advantage:

(1) adopts differential screw to pressurize, not only overcome the shortcoming of three flanged nail no axial pressure, help union of fracture, and overcome spring leaf pressure nail and draw pressure out-of-alignment shortcoming.In addition, owing to nail tail of the present utility model all enters in the cortical bone, thereby spring leaf and the excessive shortcoming of turn pressure screw afterbody apparatus have also been overcome.

(2) compare with domestic and international other screw thread pressure screw, thin (10 °～15 ° of the angle of threads of long (5mm) tooth of the pitch of its front threads, the turn pressure screw is 25 °, the nail that produce another Tianjin is 60 °) make screw little to the osseous tissue damage, the embedding sclerotin is many, its stretching resistance is 209kg after measured, thereby is difficult for skidding off from femoral head.

(3) afterbody adopts screw thread directly to screw in cortical bone, this be both at home and abroad first of wound.It not only has differential compression, and because of cortical bone thicker under itself and the tuberosity is a threaded engagement, lifting surface area is big, and pressure is little, can bear the pulling force of 428kg after measured.Add head portion and can bear the pulling force of 209kg, the connection of this nail is just very solid and reliable, thereby provides advantage for early stage function of joint activity.

(4) because the front and back threaded portion all has cutting edge, become tapping screw, thereby need not ream and tapping, nail is also tightr with combining of sclerotin.Required apparatus is few, and is simple to operate, is convenient to field operations and grass-roots unit and uses.

(5) screw special of design advance and retreat device, nail pass in and out the femoral head damage of having avoided hammering and having caused.Because nail connects firmly with the advance and retreat device, screw threads is fashionable, can avoid rocking, and is more stable than advancing with holds of other pressure screw, and it is loosening to prevent that nail from taking place in femoral head.

Claims (2)

1, a kind of medical apparatus and instruments that utilizes double thread pressurization nail treatment fracture of femoral neck, it is characterized in that this spiral shell strand nail tailing screw flight be directly screw in the cortical bone, pitch is the double thread of 4mm; Front threads is apart from being that 5mm, tooth form angle are 10 °～15 °, and the front and back screw thread all has cutting edge, and afterbody has a cross groove.

2, by the described medical apparatus and instruments of claim 1., it is characterized in that the precession of drive screw and take out femur being to use a cover aid of forming to be carried out by drill bit, advance and retreat device, holder, its advance and retreat device head has a cross projection.

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