Front self locking fixing pin plate for lumbar vertebra
One, technical field
The invention belongs to medical implants device, relate to a kind of internal fixation device of lumbar vertebra body, particularly a kind of front self locking fixing pin plate for lumbar vertebra.
Two, background technology
The internal fixation of spine technology is sick and wounded basic of treatment spinal column and important techniques means, especially in the sick and wounded treatment of lumbar vertebra.The internal fixation device that is used for lumbar vertebra at present mainly contains lumbar vertebral posterior (or rear) immobilising device, lumbar vertebra side side immobilising device and lumbar vertebra body the place ahead immobilising device.
What use always at present in lumbar vertebral posterior (or rear) immobilising device is various radix of vertebra screw solid state devices, by being connected and fixed the lumbar vertebra body between screw and the rod.This class immobilising device has following defective: (1) installs and fixes muscle and the ligament that the lumbar vertebra rear need extensively be peeled off and cut off to device, and often need excise lumbar vertebra rear structures such as vertebral plate, articuli intervertebrales and spinous process because of the needs of spinal cord and nerve decompression, wound is big and extensive, hemorrhage many, on average about 1000ml; (2) the screw location technology of installing require high, if any deflection then easy damaged spinal cord, nerve root and dural sac or fixing unstable; (3) be support fixation to lumbar vertebra front pillar and center pillar, the nail rod meets with stresses big and constant intensity is limited, is prone to broken nail, disconnected rod and fixing complication such as loosening; (4) rear and proceeds posterolateral decompression are implemented in the compressing of spinal cord and nerve root, easily caused delayed ischemic neurological deficits to increase the weight of or the generation of complication such as obstacle fully.
In the lumbar vertebra side side immobilising device, commonly used at present is vertebral body side nail-plate immobilising device and single nail rod and the excellent immobilising device of two nails.This class immobilising device has following defective: (1) installs multilamellar muscle and the ligament that this class immobilising device needs extensively to cut off the abdominal part outside and side, back, sometimes also must excise the next rib, operation technique complexity, technical difficulty height, the time is long, wound is big, and is hemorrhage many, on average is about 1200ml; (2) this class fixed system is only applicable to the sick and wounded operation of waist 1 vertebra to waist 3 vertebras, and is difficult to carry out fixing to waist 4 to sacrum 1 vertebra because of the occupy-place of blocking with the total blood vessel of ilium of ala of ilium; (3) the vertebral body side appears owing to need widely, and other vegetative nerve of easy damaged lumbar vertebra and lumbar plexus are done and branch, and causes the complication of corresponding delayed ischemic neurological deficits; (4) owing to one-sided enforcement operation technique, thus be difficult to carry out the decompression of offside nerve root canal, and be difficult to remove the offside lumbal vertebra.
Alternatively clinically at present in the immobilising device of lumbar vertebra body the place ahead mainly contain two kinds of immobilising devices.A kind of fixing for long bone of limbs used the nail-plate immobilising device, and its defective is: (1) its design is based on long bone of limbs and fixes, and the screw thread design of its nail is not suitable for the lumbar vertebra spongy bone, and the form different design of plate closes the anatomic form of lumbar vertebra; (2) Ding installation is positioned on the axis of plate substantially, and antitorque commentaries on classics and anti-side stress intensity are poor; (3) joint portion latch-up-free structure between nail and the plate to making the constant intensity deficiency, is prone to the nail-plate loose shift and deviates from, and the danger that causes mortality complication such as the preceding trunk (ventral aorta, postcava and the total blood vessel of ilium etc.) of vertebra breaks is arranged.The another kind of Elysee-watcher of being uses the PACH nail-plate immobilising device of (world) medical device company, and its defective is: (1) is only applicable to the intervertebral fixation of waist 4-5 and waist 5-sacrum 1; (2) implemented to fix by two cover nail-plates, every cover nail-plate is fixed in hypocentrum by two pieces of screws with plate, because of two cover nail-plates do not have connection each other, so the undercapacity of its antitorque turning stress; (3) joint portion does not have stable latch-up structure between nail and the plate, and is support fixation, so cause the constant intensity deficiency of whole system.
Three, summary of the invention
The present invention is intended to overcome the technological deficiency that existing lumbar vertebra immobilising device exists, and provides a kind of simple in structure, the constant intensity height, is difficult for the front self locking fixing pin plate for lumbar vertebra loosening, that safety is good, operation wound is little.
The present invention adopts such technical scheme: a kind of front self locking fixing pin plate for lumbar vertebra, include fixing head and hold-down screw, it is characterized in that fixing head is and the corresponding to circular arc of kurtorachic vertically, fixing head is along laterally being and the corresponding to circular arc of lumbar vertebra body the place ahead curved surfaces, the axial two ends of fixing head respectively are provided with three and are the screwed hole that has countersunk head that equilateral triangle distributes, wherein two screwed holes are parallel with widthwise edge, in each screwed hole hold-down screw is set, offer a circular arc otch on the excircle at the ailhead top of hold-down screw, center between three screwed holes also is provided with the countersunk head screw hole, it is discoid lock screw that ailhead is arranged in the screw hole, and the discoid ailhead of lock screw can suit with the circular arc otch at the ailhead top of three hold-down screws.
By front self locking fixing pin plate for lumbar vertebra provided by the invention, simple in structure, be provided with screw at the fixing head two ends, hold-down screw is arranged in it, between hold-down screw and fixing head all with thread lock, between the hold-down screw of every end, lock screw is arranged, when the lumbar vertebra body is fixed, the plectane kayser of the locked head of screw of countersunk head cylindrical circular arc otch of three of every end hold-down screws on the fixing head, hold-down screw can not become flexible, realize this fixedly nail-plate the safety of the fixing of lumbar vertebra body high strength and height is fixed.Because operation of the present invention is installed in human body, be to appear lumbar vertebra the place ahead by peritoneal cavity or extraperitoneal space, thus need not extensively to cut off muscle, and have the advantage that wound is little, postoperative patient recovers soon and reduce greatly complication rates such as nerve injury.The present invention can be widely used in the fusion of treatment lumbar vertebra fracture, degenerative lumbar disease, lumbar spondylolisthesis, lumbar vertebra deformity etc.
Four, description of drawings
The present invention has following accompanying drawing:
Fig. 1 is a front view of the present invention;
Fig. 2 is that the B of Fig. 1 is to view;
Fig. 3 is that the A of Fig. 1 is to view;
Fig. 4 is the sketch map of hold-down screw;
Fig. 5 is the sketch map of lock screw.
Five, the specific embodiment
Description embodiment of the present invention with reference to the accompanying drawings.As Fig. 1, Fig. 2, Fig. 3, Fig. 4, shown in Figure 5, a kind of front self locking fixing pin plate for lumbar vertebra, include fixing head 1 and hold-down screw 3, fixing head 1 is and the corresponding to circular arc of kurtorachic vertically, fixing head is along laterally being and the corresponding to circular arc of lumbar vertebra body the place ahead curved surfaces, the axial two ends of fixing head 1 respectively are provided with three and are the screwed hole that has countersunk head 2 that equilateral triangle distributes, wherein two screwed holes are parallel with widthwise edge, hold-down screw 3 is set in each screwed hole, offer a circular arc otch on the excircle at the ailhead top of hold-down screw, center between three screwed holes also is provided with countersunk head screw hole 4, it is discoid lock screw 5 that ailhead is arranged in the screw hole, and the discoid ailhead of lock screw 5 can suit with the circular arc otch at the ailhead top of three hold-down screws 3.Fixing head 1 is 25cm with the corresponding to circular arc radius of kurtorachic vertically, is 3.5cm along horizontal and the corresponding to circular arc radius of lumbar vertebra the place ahead curved surfaces.The middle part of fixing head 1 also is provided with a bar shaped vertically and observes groove 6.Hold-down screw 3 is provided with fixing head sticking department 3-1 and bone fixed part 3-2, the ailhead of hold-down screw 3 is fixing head sticking department 3-1, the nail tail is bone fixed part 3-2, the body of rod 3-3 of fixing head sticking department 3-1 is slightly larger than the body of rod 3-4 of bone fixed part 3-2, the major diameter of thread of fixing head sticking department 3-1 and bone fixed part 3-2 equates, offers a circular arc otch 3-5 on the excircle at the top of fixing head sticking department 3-1.