RU2271765C2 - Method for transpedicular fixation of affected vertebral segment - Google Patents

Abstract

FIELD: medicine, traumatology, orthopedics.

SUBSTANCE: the present innovation deals with fixing affected segment in thoracic, lumbar and sacral vertebral departments. One should apply supporting elements of transpedicular system of bars which should be crossed in frontal plane and connected together with a fixing knot to regulate the angle of bars' crossing depending upon the requirements appeared, moreover, supporting elements should be applied through pedicles of vertebral arches that increases reliability of fixation at achieving osseous ankylosis.

EFFECT: higher efficiency.

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Description

The invention relates to medicine, namely to traumatology and orthopedics, and can be used to fix the damaged vertebral segment in the thoracic, lumbar and sacral spine.

Patients with complicated spinal injury are treated promptly, fixing the affected segment of the spine with a bone autograft (V. Boychev, B. Konforti, K. Chokanov. Surgical orthopedics and traumatology. - Sofia, 1961. - P.770-771, 774-776). The main disadvantages of these operations are the difficulty of achieving intervertebral ankylosis, technically difficult and dangerous anterior operative access, additional tissue trauma associated with taking a bone graft, the need for long-term bed rest after the intervention.

Known methods for the surgical treatment of patients with spinal injuries, involving the use of various metal structures - CITO plates, KNIITO screed Ramikh-Tsivyan (A.K. Dulaev, V.M.Shapovalov, B.V. Gaidar. Closed spinal injuries of the thoracic and lumbar localization. St. Petersburg. - Mopcap AB, 2000. - P.62-64).

A known method of fixing the vertebrae using metal rods located on the back surface of the spinal column and connected by screws held transpedicularly above and below the lesion area (M.E. Muller, A. Allgover, R. Schneider, H. Willinger. Guide to internal osteosynthesis. - Ad Marginem, Moscow, 1996 .-- S.669-670). The method provides an approximate parallel direction of the adjacent support rods in the frontal plane. The support rod connects the Schantz screws located transpedicularly higher and lower, located on one side of the line drawn through the spinous processes. In the case when it is necessary to perform a laminectomy, the fixation system is supplemented with a transverse rod connecting the support rods. The transverse rod performs a dual function - it protects the spinal cord and its roots in the area of laminectomy, and is also the stabilizer of the entire fixing system.

This method is taken as a prototype, because it has common features with the claimed: the creation of fusion by stabilization using implantable metal structures, the introduction of fixing elements through the legs of the vertebral arch.

The disadvantages of the prototype are the insufficient strength of fixation by the metal structure in relation to complex rotational-flexion and rotational-inclined loads, as well as the high cost of the installed structure, limiting the possibility of using the prototype in the treatment of patients with spinal pathology.

The essence of the proposed method lies in the fact that when stabilizing a damaged vertebral segment using an implantable transpedicular metal structure, rods are used as supporting elements, which cross in the frontal plane and are interconnected by the original attachment point. As a result, the reliability of fixation of the damaged vertebral segment increases, early activation of the patient in the postoperative period is allowed. You can use the proposed method in combination with decompression laminectomy - creates protection of the contents of the spinal canal at the level of the intersection, reduces the cost of treatment by reducing the number of structural elements. When superimposing the rods on each other, it is possible to simulate the intersection zone by bending one of the rods. The mounting unit allows you to adjust the angle of the crossing of the rods depending on the requirements from 0 to 170 degrees. As the transpedicularly inserted elements of the metal structure, standard Shants screws or pedicular screws open on the side are used.

The method is illustrated by drawings 1, 2. Figure 1 shows a schematic representation of transpedicular fixation according to the proposed method in the frontal plane. Figure 2 - mount.

Description of the mount. The mount is presented in the form of two hollow cylinders with a diameter of 6.2 mm and a length of 15 mm. On one of the side surfaces of each cylinder there is a supporting platform of a trapezoidal shape. In the center of the bearing pad of one of the cylinders there is a round hole with a threaded thread, corresponding to the diameter of the screw introduced into it. A longitudinal hole is provided in the support area of the other cylinder with edges countersinked under the cap of the fixing screw.

The method is as follows. After installing the transpedicular screws, the required length of the rods with a diameter of 6 mm is selected. The rods are modeled using special plates, taking into account the physiological bends of the spine and the specific biomechanical situation. If necessary, the spinous process of the fixed vertebra and protruding anatomical bone formations of the posterior vertebral complexes are economically resected for optimal adaptation of the rods to the bone structures.

Then on the support rods are placed the cylinders that make up the mount, by turning their support pads to each other. The design is mounted on the inserted transpedicular screws using nodes in such a way that the rods, placed one above the other, intersect in the frontal plane. After that, the holes of the supporting platforms of the cylinders are put on, put on the crossed support rods, superimposing on top of the supporting platform with a longitudinal hole. Achieve the stop of the upper supporting platform in the wall of the second cylinder. The supporting platforms of the cylinders are fixed to each other using a screw, thereby linking the crossed rods and four transpedicular screws into a single system.

Clinical example

Patient P-na, 46 years old, was admitted to the Samara Regional Clinical Hospital. Kalinina November 21, 2000, 12 days after the catastrophe with a diagnosis of Closed comminuted unstable fracture dislocation L ₂ with contusion and compression of the spinal cord, lower paraparesis, pelvic organ dysfunction.

After the examination and detailing the nature of the existing pathology, the patient underwent surgery - decompressive laminectomy L ₂ , posterior-lateral decompression of the spinal cord, osteosynthesis of L ₁ -L ₂ vertebrae with a transpedicular rod apparatus according to the proposed method. The postoperative period was uneventful.

The wound healed by primary intention. The patient was allowed to get up and walk with crutches a week after the operation. The function of the pelvic organs returned to normal. Examined after 3 months. after surgery. No complaints, no neurological disorders were detected. On the control radiograph - signs of bone ankylosis between the first, second and third lumbar vertebrae, there are no signs of instability.

Thus, the proposed method is simple in the technique of execution, less traumatic and can be recommended for use in practical health care.

Claims (1)

A method of transpedicular fixation of a damaged vertebral segment, including the creation of fusion by stabilization using an implantable metal structure, the introduction of fixing elements through the legs of the vertebral arch, characterized in that rods are used as supporting elements placed on the back surface of the spine, crossing them in the frontal plane and connecting between each other by the mount.

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