RU2219865C1 - Device for stabilization of segments of spinal column - Google Patents

Abstract

FIELD: medicine, in particular, traumatology, orthopedics and neurosurgery. SUBSTANCE: the device has plates with holes for the fastening screws in the form of a monolithic shaped member bent in the vertical and horizontal planes, in which the plates have the shape of chutes with edges bent back outside, located at an angle to one another in the vertical plane and connected by a curved crosspiece. Perforated holes are made on the entire area of the plates. The holes for the fastening screws are positioned along the edges of the plates and areas of their joint to the crosspiece. The invention provides for reliable stabilization of the injured segment, and at conduction of laminectomy - a simultaneous plasty of the rear structures of the vertebral column, which makes it possible to activate the patient in the early periods and prevent rough cicatrical adhesions, i.e. development of postlamectomic syndromes. The construction fulfils a double function, being a fixative and an implant at the same time. EFFECT: enhanced efficiency. 3 dwg

Description

 The invention relates to medical equipment, namely to neurosurgery, orthopedics, and can be used to treat diseases of the spine: unstable vertebral fractures, complicated spinal injuries, vertebral injuries due to the presence of tumors and metastases in them, spondylolisthesis in case of injuries or degenerative changes - as fixative and implant.

 A device is known for stabilizing damaged segments of the spine (RU 2095030, class IPC A 61 B 17/70, 1998), comprising two threaded rods and transverse plates, at the ends of which holes are made for holding the rods and holes for fixing screws. To adjust the plates, nuts are dressed on the rods with the possibility of preloading each end of the plate from two sides. The device is used as follows. Provide rear access to the damaged segment of the spine. Spinal laminectomy is performed, spinal deformity is eliminated. Set the transverse plates. Through the holes with a thin drill, grooves are formed through the legs of the arches for installing screws in the vertebral bodies. Then the plates are put on the rods with adjusting nuts on each end from above and below, set them in the correct position and the screws are passed through the grooves to fix the structure to the vertebral bodies (broken and adjacent). Adjusting nuts correct the position of the plates, check the reliability of fusion.

 However, this device has several disadvantages.

 It does not provide reliable stabilization of the damaged segment under vertical load.

 Insufficient rigidity of fixation during rotational movements creates the conditions for the inconsistency of fusion.

 The use of the device can cause bone resorption around the screws and, as a result, lead to the loss of its stabilizing function by the design. For these reasons, its use is contraindicated in patients with osteoporosis of the spine.

 When using this design, there is a high probability of development of the cicatricial-adhesive process of the spinal canal (laminectomy syndrome), since it does not provide for the closure of the defect.

 The device can only be used as a latch.

 As the closest analogue, a device was adopted for stabilization of damaged segments of the spine — the Kaplan – Antonov spine fixator (A. V. Kaplan. Damage to bones and joints. - M., 1979, p. 147 and 148), containing two plates having an outer corrugated and internal smooth surface, which is adjacent to the spinous processes.

 In the middle part of the plates, holes are made in the form of slots with a jumper in the center for the passage and movement of fixing screws that connect the plates using rectangular washers and nuts grooved on one side.

 Fixation of the spine is performed under general anesthesia. The spinous canes and arches of the corresponding three vertebrae are exposed in the midline and the periosteum is separated.

 A special awl or drill drills the spinous processes of the vertebrae to be fixed. On both sides of the spinous processes, metal plates are laid. Through the slots of the plates and spinous processes, screws are passed that are screwed with nuts. The wound is sutured in layers.

 A disadvantage of the known device is the low rigidity of fixation, which is carried out only for the spinous processes of the vertebrae, that is, in one plane.

 When conducting a laminectomy preceding fixation, the application of only plates does not allow for stability of the spine and creates the conditions for the development of postlaminectomy syndrome. It is possible to loosen the screws and cut them from the spinous processes due to perifocal bone resorption or excessive activity of patients, as well as against the background of age-related osteoporosis.

 The device thus has limited functionality.

 The objective of the invention is to provide a device for the stabilization of segments of the spine, having wide functionality and providing reliable stabilization and plasticity of the posterior structures of the spinal column.

 The essence of the invention lies in the fact that the device for stabilizing segments of the spine, containing plates with holes for mounting screws, is made in the form of a monolithic figured element curved in the vertical and horizontal planes, in which the plates are in the form of gutters with outwardly curved edges located at an angle to each other to each other in a vertical plane and connected by a rounded jumper, while over the entire area of the plates perforations are made, and holes for the mounting screws are placed along the edge plates and the zones of their connection with the bridge.

 Using the invention allows to obtain the following technical result.

 The device has wide functionality. It can be used both for traumatic injuries of the spine, and for tumor and degenerative diseases and has no contraindications.

 It allows you to reliably stabilize the damaged segment, and when performing a laminectomy, simultaneously plasticize the posterior structures of the spinal column, which makes it possible to activate the patient in the early stages and to avoid harsh scar adhesions, i.e. the development of postlaminectomy syndrome. In this case, the design performs a dual function, being both a retainer and an implant.

 In some cases, for example, when a laminectomy is performed to remove a tumor of the spinal canal or when performing surgery on the spinal cord to relieve pain, the device is used only as an implant for plastic surgery of the posterior structures of the spine.

 The manufacture of the device from "chemically pure" titanium allows you to prevent the occurrence of complications in the form of suppuration and rejection of the implant, which can be in the patient’s body for life without the need to remove it.

 The design is simple and easy to use. Moreover, in accordance with the specified parameters - the level of damage to the segment and the number of affected vertebrae in it, the shape of the bends, the angle between the plates, the length, and also the fixation method can vary.

 The technical result is achieved due to the implementation of the device in the form of a monolithic element, curved in the form of physiological bends of the spine and the transverse relief of the vertebrae of an elastic material - titanium, which provides high fixation rigidity.

 The possibility of simultaneous fixation in two planes - through the spinous processes and legs of the vertebral arches creates the conditions for reliable stabilization of the damaged segment of the spine, which in turn avoids rotational displacements in the sagittal and frontal planes.

 In the presence of fractures and other damage to the spinous processes, fixation is possible only through the legs of the vertebral arches with the stabilization of the vertebral segment.

 The presence of holes along the zone of connection of the plates with the jumper provides holding screws, both through the above- and through the underlying spinous processes. Placing the holes for the fixing screws along the laterally folded out lateral edges of the plates makes it possible to conduct transpedicular screws through the legs of the vertebral arches.

 The implementation of holes in the form of a perforation mesh over the entire area of the plates facilitates the design and, therefore, reduces its pressure on bone and soft tissues, and also contributes to a more complete integration of the implant with tissues.

 The rounded bridge repeats the shape of the spinous processes, and the lateral plates are curved along the relief of the posterior semicircle of the vertebrae. This makes it possible to simulate the design in the form of the posterior bone structures of the spine and produce plastic surgery of the latter.

 A device for stabilizing spinal segments is shown in FIG. 1-3.

 Figure 1 shows a top view of the device, figure 2 is a side view, figure 3 is its cross section.

 The device is made in the form of a monolithic figured element, curved in the vertical and horizontal planes. It contains two plates 1, 2, which are curved in the shape of the posterior semicircle of the vertebrae to the end in it. They have the shape of gutters with outwardly curved edges 3, located at an angle to each other in a vertical plane and connected by a rounded jumper 4, repeating the shape of the spinous processes of the vertebrae. Perforations are made over the entire area of the plates 1, 2. Holes 6 for mounting screws 7 are placed along the edges of the plates 3 and along the zones of their connection with the jumper 4.

 The device is used as follows. Provide rear access to the damaged segment of the spine. According to indications, a vertebral laminectomy is performed, a critical plane is formed. If necessary, carry out an audit of the spinal cord, treatment of the lesion. Eliminate the deformation of the spinal column. Choose a device that is in shape and size that matches the level of damage to the segment.

 The implant is formed using scissors and power devices. The device is installed so that the jumper 4 rests on the spinous processes of the vertebrae, and the plates 1, 2 are in contact with their arches. Using the lateral awl, holes are formed in the spinous processes above and below the affected vertebrae.

 Fixing screws 7 are passed through holes 6 located along the connection zones of the plates 1, 2 and jumpers 4 into the spinous processes, fix them with nuts.

 Then, with an awl, holes are formed in the legs of the arches and fixing screws 7 are passed through holes 6 located along the edges of the plate 3 in the vertebral bodies. For fixing through the legs of the arcs, self-tapping screws are used, the thickness and length of which varies depending on the level of the affected segment. The wound is sutured in layers.

Claims (1)

A device for stabilizing segments of the spine, containing plates with holes for mounting screws, characterized in that it is made in the form of a monolithic figured element curved in the vertical and horizontal planes, in which the plates are in the form of grooves with outwardly curved edges located at an angle to each other in the vertical plane and connected by a rounded jumper, while over the entire area of the plates perforations are made, and holes for mounting screws are placed along the edges of the plates and zones their connection with a jumper.

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