CN103800101B - An anti-dislocation non-fusion artificial cervical spine and intervertebral disc system - Google Patents

Abstract

The invention discloses a kind of anti-dislocation formula non-fused artificial cervical and intervertebral disc system, comprise vertebral body parts and be connected to two soleplate parts of vertebral body parts upper and lower side respectively by dome articulation structure and side, front and back L-type anticreep bit architecture; Described two soleplate parts are respectively equipped with soleplate hold-down screw.The present invention at once can play supporting role after cervical vertebral body subtotal ectomy, and the motor function of normal cervical vertebra is substituted by carrying intervertebral coupling part, stress during cervical vertebra moving can be disperseed, reduce pressure in neighbouring section intervertebral disc and zygapophysial joints, effectively prevent the Adjacent segment degeneration caused by fusion.In addition, can Bony union be realized by the hydroxyapatite coating layer on bone grafting and native system surface and can it stablize.Operating difficulty is less, and wound is little, is convenient to promote.Due to the existence of the anti-roll off device of native system, postoperative long-term stability can be obtained.

Description

An anti-dislocation non-fusion artificial cervical spine and intervertebral disc system

technical field

The invention belongs to the technical field of medical prosthesis manufacturing, and relates to an artificial cervical vertebra and intervertebral disc system, in particular to a dislocation-preventing non-fusion artificial cervical vertebra and intervertebral disc system.

Background technique

At present, anterior cervical corpectomy with fusion (ACCF) is a commonly used surgical method for the treatment of cervical spondylosis, cervical vertebral fracture with spinal cord compression, or old fracture and dislocation with incomplete spinal cord injury. In this operation, the corresponding vertebral bodies and intervertebral discs are exposed through the anterior approach, and vertebral screws are respectively placed in the upper and lower adjacent vertebral bodies to be resected. ) Medial subtotal resection of most of the vertebral body and posterior longitudinal ligament of the vertebral body, fully decompressed under the condition that the spinal cord and nerve roots were protected, and implanted a suitable length of bone graft (autologous/ Allogeneic) or titanium cage (filled with cancellous bone), select the appropriate anterior cervical plate fixation and upper and lower vertebral bodies. The advantage of this operation is that it can obtain immediate postoperative stability and provide a stable biomechanical environment for the recovery of neurological function. A large number of clinical studies have confirmed that it has a good surgical effect. However, long-term follow-up studies have found that some patients have problems such as bone graft absorption, collapse, loosening, falling off, and sinking of the titanium cage after surgery. Biomechanical studies have shown that after fusion, the motion function of the corresponding vertebral body unit is lost, and the pressure and stress transfer in the adjacent segmental intervertebral disc and facet joint increase. On imaging, some patients show intervertebral disc degeneration or protrusion, loss of intervertebral space height, formation of adjacent vertebral bodies or facet joint osteophytes, changes in spinal sequence, segmental instability or slippage, and spinal canal stenosis may occur in severe cases, resulting in spinal cord compression , resulting in severe neurological symptoms. Hilibrand et al. reported the long-term follow-up of 374 cases of anterior cervical fusion for cervical spondylosis. The longest follow-up was 21 years, and found that the annual incidence of symptoms of adjacent segmental lesions was 2.9%, and 25.6% of cases occurred 10 years after surgery. Adjacent segmental disease. (HilibrandAS, CarlsonGD, PalumboMA, et al. Radiculopathy and myelopathy yatsegments adjacent to the site of a previous anterior cervical arthrodesis [J]. Journal of Bone and Joint Surgery-American Volume, 1999, 81A (4): 519-528.)

In order to effectively avoid problems such as implant collapse and loosening, some scholars have begun to implant artificial vertebral bodies in some patients to maintain or rebuild the stability of the spine in order to obtain a long-term stable biomechanical environment. In 1969, Hamdi first reported the implantation of artificial vertebral bodies in patients with lumbar spine tumors (HamdiFA. Prosthesis for anexcised lumbar verticalebra: apreliminary report [J]. Canadian Medical Association Journal, 1969, 100 (12): 576.). Afterwards, people continued to improve the artificial vertebral body, and metal materials and new composite materials with better compatibility with human tissue gradually appeared. The fixation method has also developed from the original steel plate or screw-rod assisted fusion fixation to the current simple self-locking. The artificial vertebral body is implanted for fusion and fixation, and the surface of the artificial vertebral body is treated with a bioactive material coating to achieve a better fusion with the surrounding bony knots. Vertebral body, the height-adjustable artificial vertebral body that is applicable to different crowd also appeared now. According to the clinical follow-up observation of the artificial vertebral body, good stability, spinal sequence, and vertebral body height can be obtained after the implantation of the prosthesis. Lu Chaoliang, Song Yueming et al. performed anterior subtotal corpectomy, spinal canal decompression, bone grafting with n-HA/PA66 vertebral body support, and internal fixation with plates and screws on 84 patients with lower cervical spine fracture and dislocation for a period of 6- The 24-month follow-up found that imaging examinations showed that all patients had bone graft fusion, and the cervical sequence, intervertebral height, cervical spine stability, and position of the support body were maintained well, and the support body did not sink or shift. (Lv Chaoliang, Song Yueming, Liu Hao, etc. Application of nano-hydroxyapatite/polyamide 66 vertebral body support in anterior surgical reconstruction of lower cervical spine fracture and dislocation[J]. Chinese Journal of Surgery, 2012,50(4):338- 341.)

However, the aforementioned artificial vertebral body does not break through the limitation of adjacent segment degeneration caused by fusion. The emergence of movable spinal fixation technology conceptually solves the problem of adjacent segment degeneration after fusion. It not only maintains the motor function and biomechanical characteristics of the spine, but also restores the height of the intervertebral space and the alignment of the spine. At present, artificial cervical disc replacement has been widely used at home and abroad. A large number of clinical observations have found that artificial cervical disc replacement can achieve satisfactory results in the treatment of cervical spondylosis. Due to the limited surgical indications for artificial cervical intervertebral disc placement: single-segment or double-segment cervical disc herniation compresses the spinal cord or nerve roots, other types of cervical fusion such as subtotal cervical corpectomy, decompression and fusion still cannot be replaced by artificial cervical intervertebral disc. Disc replacement replacement.

To sum up, the current existing technology cannot avoid the disadvantages of loss of motor function after cervical subtotal corpectomy decompression and fusion and the problem of accelerated degeneration of adjacent segments caused by it.

In order to effectively restore the height of the intervertebral space and the motion function of the corresponding segments, delay the occurrence of adjacent segment degeneration, and avoid problems such as implant collapse and loosening, we designed a new anti-dislocation artificial cervical spine and intervertebral disc system.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide an anti-dislocation non-fusion artificial cervical vertebra and intervertebral disc system, which has both the support function of the artificial vertebral body and the non-fusion feature of the artificial intervertebral disc, and the joint between the vertebral body and the intervertebral disc The anti-dislocation function of the two is realized through a special structure. This system can obtain the immediate stability after subtotal corpectomy and prosthesis replacement after anterior cervical surgery, making its activity highly bionic with that of the normal cervical spine.

The purpose of the present invention is achieved through the following technical solutions:

This anti-dislocation non-fusion artificial cervical spine and intervertebral disc system includes vertebral body components and two endplate components connected to the upper and lower ends of the vertebral body components through the dome joint structure and the front and rear L-shaped anti-dislocation structures respectively; The plate parts are respectively provided with end plate fixing screws;

The upper and lower parts of the vertebral body are provided with circular joint sockets, the two ends are provided with annular grooves, and the front and rear sides of the two ends are provided with forward and backward arc-shaped flat plates; the sides of the vertebral body are provided with a number of left and right through hole;

The dome articulation structure includes a dome articular surface arranged on the end plate part and a circular joint socket arranged on the upper and lower surfaces of the vertebral body parts to adapt to the dome articular surface. bread in the round joint socket;

The L-shaped anti-dislocation structure includes an L-shaped structure arranged on the front and rear sides of the end plate parts, an annular groove arranged on the end of the vertebral body part, and an arc-shaped flat plate arranged on the front and rear sides of the end of the vertebral body part. The dislocation structure matches the L-shaped structure with the annular groove, and the arc-shaped flat plate restricts the movement of the L-shaped structure relative to the vertebral body parts on the endplate parts to prevent dislocation between the endplate parts and the vertebral body parts.

Further, the above-mentioned end plate component includes a circular plate, a cylinder and a dome articular surface structure are provided in the lower middle of the circular plate, and a sawtooth structure is provided on the circular plate; the front and rear sides of the lower part of the circular plate are provided with L-shaped dislocation prevention structure, the front side of the upper part of the circular plate is provided with a vertical arc-shaped plate structure, and the vertical arc-shaped plate structure fixes two end plate component fixing screws through two internally threaded screw holes; the end plate fixes The screw is at an angle of 20° to the circular plate.

Further, there is a sawtooth structure on the above circular plate; the height of the sawtooth structure is 1 mm at the center and decreases towards the periphery.

Further, the surface of the zigzag structure is provided with a biological hydroxyapatite coating, and the thickness of the hydroxyapatite coating is 20 μm.

Further, the left and right sides of the above-mentioned vertebral body parts are provided with a biological hydroxyapatite coating with a thickness of 20 μm treated by plasma oxidation technology.

Further, the front end of the above-mentioned endplate fixing screw is pointed, the rear end of the endplate fixing screw is a nut, and the end near the nut of the endplate fixing screw is thicker than the proximal tip.

The present invention has the following beneficial effects:

The present invention can play a supporting role immediately after subtotal cervical vertebral body resection, and replace the normal cervical motion function with its own intervertebral connection part, which can disperse the stress of the cervical vertebrae during activities and reduce the intervertebral disc and facet joints in adjacent segments. Pressure can effectively prevent adjacent segment degeneration caused by fusion. In addition, bony fusion and stabilization can be achieved through bone grafting and the hydroxyapatite coating on the surface of this system. The operation is less difficult, the trauma is small, and it is easy to promote. Due to the existence of the anti-dislocation device of this system, long-term postoperative stability can be obtained.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is a schematic structural view of a vertebral body part of the present invention;

Fig. 3 is the top view of Fig. 2;

Fig. 4 is the sectional view of Fig. 3;

Fig. 5 is a schematic diagram of the endplate structure of the present invention;

Figure 6 is a top view of Figure 5;

Fig. 7 is the front view of Fig. 5;

Figure 8 is an isometric view of Figure 5;

Among them: 1 is the vertebral body part; 2 is the end plate part; 3 is the end plate fixing screw; 4 is the ring groove structure; 5 is the arc-shaped flat plate; 6 is the left and right through holes; plate; 9 is a dome articular surface; 10 is an L-shaped anti-dislocation structure; 11 is a vertical arc plate structure; 12 is a sawtooth structure; 13 is a screw hole.

detailed description

The present invention is described in further detail below in conjunction with accompanying drawing:

Referring to Fig. 1, the anti-dislocation type non-fusion artificial cervical spine and intervertebral disc system of the present invention includes a vertebral body part 1 and two endplate parts 2 connected to the upper and lower ends of the vertebral body part 1 through a dome joint structure respectively; The wall is provided with several through holes 6; the two end plate parts 2 are respectively provided with end plate part fixing screws 3. Each component that forms the present invention is described in detail below in conjunction with accompanying drawing:

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the vertebral body part 1 is provided with circular glenoid structures 7 on the upper and lower sides, annular groove structures 4 at both ends, and several left and right through hole structures 6 in the middle.

In the preferred embodiment of the present invention: the upper and lower parts of the vertebral body part 1 each have a circular glenoid structure 7 with a depth of 2.5 mm that matches the dome articular surface of the lower part of the endplate part 2. Seen three-dimensionally, the circular joint The socket structure is the lower 2.5/20 part of a sphere with a diameter of 20mm, and this structure encloses the dome articular surface 9 of the lower part of the endplate part 2, forming a dome joint with it; each end of the vertebral body part 1 has an annular groove structure 4 , the structure has arc-shaped flat plates 5 protruding forward and backward respectively on the front and rear sides near the upper and lower sides of the vertebral body; the middle part of the left and right sides of the vertebral body part 1 is provided with a number of left and right through holes 6; the left and right sides and the inner surfaces of all through holes are It is a frosted structure with a hydroxyapatite coating on the surface to achieve good bony fusion and obtain good stability and support.

Referring to Fig. 1, Fig. 5 and Fig. 6, the above-mentioned dome articular structure includes the dome articular surface 9 on the end plate component 2 and the circular shape adapted to the dome articular surface 9 arranged at the end of the vertebral body component 1. Joint fossa7. The dome articular surface 9 cooperates with the circular articular socket 7 to realize the movement function in all directions of the intervertebral connection.

In the best embodiment of the present invention: the dome articular surface is connected by 2/20 of a sphere with a diameter of 20mm and a matching cylindrical structure. The dome articular surface 9 coincides with the circular articular fossa 7 at the upper and lower ends of the vertebral body respectively. The upper and lower circular articular fossa 7 completely coincides with the dome articular surface 9 on the front, rear, left, and right sides (that is, the diameter is 20 mm). Such an intervertebral connection has a large contact area, which ensures that the prosthesis can play a stable supporting role under the condition of axial stress of the spine, and at the same time can reduce the friction of the articular surface; the dome joint structure can realize the normal vertebral body. sports. At present, the existing clinical artificial vertebral body has a support function but does not have a movement function, while the movement function of an artificial intervertebral disc is only suitable for the preservation of intervertebral space movement and does not have a support function. Therefore, the intervertebral connection formed by the uniquely designed dome joint can not only realize the support function of the artificial vertebral body, but also preserve the movement function of the intervertebral space, thereby slowing down the degeneration of adjacent segments caused by the increased stress after fusion. progress.

As shown in Fig. 5, Fig. 6, Fig. 7, and Fig. 8, the end plate component 2 includes a circular plate 8, and there is a vertically fixed dome articular surface 9 at the center of the lower part of the circular plate 8, and there is one on the front and rear sides of the circular plate 8 respectively. L-shaped anti-dislocation structure, the vertically upward arc-shaped plate structure 11 above the front side of the circular plate 8 has two internally threaded screw holes 13 that form a certain angle with the circular plate 8 in two directions and are fixed with two endplate fixing screws 3 ; The sawtooth structure 12 is provided on the circular plate 8 .

In the best embodiment of the present invention: the L-shaped anti-dislocation structure of the end plate part 2 forms a restrictive relationship with the annular groove 4 at the end of the vertebral body part 1 and the arc-shaped plates 5 at the front and rear sides of both ends. The L-shaped structure 10 is embedded in the groove structure 4, and the arc-shaped plate structure 5 is surrounded by the L-shaped structure 10 to prevent dislocation when the end plate and the vertebral body of the system move relative to each other. After the implantation of the vertebral body components, the patient needs to perform neck mobility exercises in the early stage, but since the vertebral body components have not yet formed a stable bony fusion with the surrounding tissues, the L-shaped anti-dislocation structure can limit the Dislocation due to overmobility avoids the risk of spinal cord compression.

There are two screw holes 13 for screw fixing in the middle of the arc-shaped plate that is vertically upward on the front side of the circular plate 8. These two screw holes 13 are threaded and cooperate with the end plate fixing screws 3. The terminal plate component screw 3 of the present invention is a self-tapping screw, and its rear end is a nut, and the proximal nut end of the terminal plate fixing screw 3 is slightly thicker than its proximal tip end. The endplate fixing screw 3 can be implanted into the corresponding vertebral body at an angle of 20° with the circular plate. The endplate fixing screw 3 is matched with the screw hole 13 with internal thread. The screw 3 of the plate part can obtain greater holding force, and realize the tight fixation of the end plate and the adjacent vertebral body.

The upper part of the circular plate 8 is a sawtooth structure 12, the height of which is 1mm at the center, and decreases to the surroundings, which is more suitable for the anatomical shape of the upper and lower endplates of the adjacent vertebral bodies, and can achieve better cooperation of the adjacent vertebral bodies. The surface of the sawtooth structure 12 There is a biological hydroxyapatite coating formed by plasma oxidation technology, and the thickness of the coating is about 20 μm. All the upper surface treatments can accelerate the early fusion of the endplate structure and the adjacent vertebral body, which is conducive to the realization of biological fusion and long-term stability.

In summary, the dislocation-preventing non-fusion artificial cervical spine and intervertebral disc system of the present invention is suitable for diseases obtained from anterior cervical subtotal corpectomy, such as: herniated cervical intervertebral discs in two adjacent segments, vertebral body tumors, vertebral discs, etc. Body tuberculosis, non-neurally impaired cervical burst fractures, compression fractures, etc. In addition, this system can also be used for other types of cervical diseases with severe degeneration of adjacent segments after artificial cervical intervertebral disc revision and cervical fusion. The specific implementation methods in the operation are described below with respect to intervertebral disc removal, subtotal vertebral body resection, and replacement of this system:

Routine preoperative examinations are performed for patients with indications for this operation, and the trachea and esophagus are moved in parallel, and urination and defecation exercises are performed on the bed; the patient is placed in a supine position, with soft pillows on both shoulders, the head and neck are naturally stretched back, and sandbags are placed on the back of the neck Or a cork pillow, the back of the occiput is padded with a soft head ring, and small sandbags are placed on both sides of the head to prevent rotation during the operation; an anterior cervical incision is used, and the length of the incision is generally 3-5 cm; the carotid sheath and cervical visceral sheath are accurately determined, Use the index finger to perform blunt release along the separated gap, and then gently separate the deep part to reach the front part of the vertebral body and intervertebral disc; pull the trachea and esophagus to the midline with a retractor, and pull the carotid sheath slightly to the right. Reach the vertebral body and prediscal space; use long tweezers to lift the prevertebral fascia and cut it layer by layer, then separate this layer of fascia longitudinally, and gradually expand up and down to expose the vertebral body and intervertebral space; in the center of the upper and lower vertebral bodies of the diseased vertebra Screw in the spreader screws respectively, insert the spreader on the spreader screws, and spread the upper and lower ends; determine the upper and lower intervertebral discs of the corresponding vertebral body, cut the fibrous ring with a sharp knife, and take out the broken intervertebral disc tissue with the nucleus pulposus forceps ; Use a three-joint rongeur to bite off the anterior cortical bone and most of the cancellous bone of the fractured vertebra. Pause when approaching the posterior edge of the vertebral body, scrape off all the intervertebral discs and endplates with a curette, separate the gap between the posterior edge of the vertebral body and the posterior longitudinal ligament with a nerve dissector, and insert the thin impact rongeur to gradually remove the vertebral body. At this time, a rectangular decompression groove is formed; the bottom edge of the decompression groove is carefully enlarged, and the compressor is completely removed to complete the decompression; the system is assembled in vitro, and the circles of the upper and lower endplate components are The top articular surfaces were respectively placed into the circular grooves on the upper and lower sides of the vertebral body along the side of the vertebral body, and rotated 90° so that the vertically upward arc-shaped plate of the endplate was located on the front side, and the obtained vertebral bone The quality is crushed and implanted into several bone graft holes through the side of the vertebral body; adjust the height of the vertebral body spreader to restore the height of the anterior column of the cervical spine to normal, put the system into the decompression groove, and make the upper and lower The endplates are in contact with the lower and upper surfaces of the adjacent vertebral bodies; 4 upper and lower screws are implanted at an angle of 20° to the upper and lower surfaces of the adjacent vertebral bodies to fix the upper and lower endplates; loosen the vertebral body spreader, Make the system tightly fitted, and after the X-ray machine is correct, the wound is rinsed, drainage is placed, and sutured layer by layer. Routine care after the operation, the neck can be moved normally one day after the operation.

Claims (5)

1. an anti-dislocation formula non-fused artificial cervical and intervertebral disc system, it is characterized in that, comprise vertebral body parts (1) and be connected to two soleplate parts (2) of vertebral body parts (1) upper and lower side respectively by dome articulation structure and side, front and back L-type anticreep bit architecture; Described two soleplate parts (2) are respectively equipped with soleplate hold-down screw (3);

Described vertebral body parts (1) top and bottom are provided with rounded knuckle nest (7), and both ends are provided with annular groove (4), and before and after both ends, side is provided with arc flat board (5) forward, backward; Described vertebral body parts (1) side is provided with some left and right through hole (6);

Described dome articulation structure comprises the rounded knuckle nest (7) that the dome articular surface (9) be arranged on soleplate parts (2) and the top and bottom being arranged on vertebral body parts (1) and described dome articular surface (9) adapt, and dome articular surface (9) wraps in rounded knuckle nest (7) by this dome articulation structure;

Described L-type anticreep bit architecture comprise be arranged on side before and after soleplate parts (2) L-type structure (10), be arranged on the annular groove (4) of vertebral body parts (1) end, be arranged on the arc flat board (5) of side before and after vertebral body parts (1) end, L-type structure (10) matches with annular groove (4) by this L-type anticreep bit architecture, arc flat board (5) restriction L-type structure (10) moves at soleplate parts (2) opposing vertebral body parts (1), prevents soleplate parts (2) and vertebral body parts (1) from dislocating; Soleplate parts (2) comprise plectane (8), cylinder and dome articular surface (9) is provided with at the lower Middle face of plectane (8), plectane (8) is above provided with broached-tooth design (12), and the left and right side of described vertebral body parts (1) thickness be provided with through plasma oxidation technical finesse is the biology hydroxyapatite coating layer of 20 μm.

2. anti-dislocation formula non-fused artificial cervical according to claim 1 and intervertebral disc system, it is characterized in that, the forward and backward side of described plectane (8) bottom is provided with L-type structure (10), the front side on described plectane (8) top is provided with vertical arc plate structure (11), and described vertical arc plate structure (11) fixes two pieces of soleplate hold-down screws (3) by threaded screw (13) in two; Described soleplate hold-down screw (3) and described plectane (8) are in 20 ° of angles.

3. anti-dislocation formula non-fused artificial cervical according to claim 2 and intervertebral disc system, is characterized in that described plectane (8) there is broached-tooth design (12); The height of described broached-tooth design (12) is 1mm in center, successively decreases to surrounding.

4. anti-dislocation formula non-fused artificial cervical according to claim 3 and intervertebral disc system, it is characterized in that, the surface of described broached-tooth design (12) is provided with biology hydroxyapatite coating layer, and described hydroxyapatite coating layer thickness is 20 μm.

5. anti-dislocation formula non-fused artificial cervical according to claim 1 and intervertebral disc system, it is characterized in that, the front end of described soleplate hold-down screw (3) is tip, described soleplate hold-down screw (3) rear end is nut, and the nearly screw cap end of this soleplate hold-down screw (3) is most advanced and sophisticated thicker than near.