RU2540093C2 - Vertebroplasty technique - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: compression spine is imaged preoperatively above and below the arranged spines. The prepared image is used to measure along an anterior periphery of spines in the sagittal plane a vertebral body height above the compression spine, h_a, a vertebral body height below the compression spine, h_b, a compression vertebral spine height h_k, a length of the destroyed segment of the compression spine m. The compression spine dimensions d₁ and d₂ in the middle portion are measured in an axial plane taking into account that the vertebral body is shaped as an elliptic cylinder, wherein d₁ is its greater semi-axis, d₂ is a smaller one; a cement amount is calculated by formula

wherein

h=(h_a+h_b)/2-h_k).

EFFECT: more accurate determination of the introduced bone cement amount that provides higher quality of patient's treatment.

1 ex, 5 dwg

Description

The invention relates to medicine, namely to neurosurgery and traumatology, and is intended for the surgical treatment of vertebral fractures by means of percutaneous vertebroplasty of patients with traumatic or degenerative-dystrophic diseases (pathological fracture due to osteoporosis), as well as tumor processes.

State of the art

It is known that the generally accepted methods of surgical treatment (transpedicular fixation) of uncomplicated fractures of the vertebral bodies due to their morbidity and satisfactory somatic status of the patient are impractical, and older and older patients with concomitant diseases are contraindicated. To ensure the stabilization and consolidation of damaged vertebrae, these patients undergo a minimally invasive method of surgical treatment - vertebroplasty.

The method is effective, but when using bone cement in large doses, complications can occur in the form of leakage outside the vertebral body, including into the cavity of the spinal canal, which leads to compression of the spinal cord and spinal nerves. At the same time, the effectiveness of vertebroplasty is determined by a sufficient amount of cement injected into the body of the damaged vertebra.

A known method of vertebroplasty of the vertebral body with compression fractures by introducing a cementitious substance of low viscosity 1 / 2-1 / 4 of the volume of the cavity through the puncture needle under the control of the electron-optical transducer, then the osteogenic substance until the cavity is filled and after a few minutes enter 0, 5-1.0 ml of cement of high viscosity as a cork (RF patent No. 2324447, CL AB 17/56, publ. 05/20/2008).

A known method of percutaneous vertebroplasty for injuries and diseases of the spine, consisting in the introduction through the same puncture needle of a sequentially binder into the affected vertebra, an adhesive composition is introduced for vascular thrombosis of 1.0-2.0 ml, and then bone cement 3.0 -5.0 ml (RF patent No. 2432137, class AB 17/56, publ. 10/27/2011).

The disadvantages of these methods are the subjective and low accuracy of determining the volume of injected bone cement into the body of the damaged vertebra, as well as with the excessive introduction of a cementing composition, the possibility of complications in the form of the outflow of the latter extra-intravertebrally with the development of the corresponding neurological symptoms.

The closest technical solution (prototype) is a vertebroplasty method (RF patent No. 2432910, class AB 17/56, publ. 10.11.2011). In preoperative planning, the height and area of the sides of fragments of the damaged vertebral body are recorded, then the volume of each fragment is determined by the formula:

, $$V=\left(S_{\mathrm{one}}+S_2+\sqrt{S_{\mathrm{one}}\cdot S_2}\right)\cdot \frac{H}{3}$$

,

where V is the volume of the fragment of the damaged vertebral body; S1 is the area of the side of the fragment of the damaged vertebral body, which is facing ventrally; S2 is the area of the side of the fragment of the damaged vertebral body, which is facing dorsally; H is the height of the fragment of the damaged vertebral body. Then, under control through the base of the legs of the vertebral body, puncture needles are brought to the middle of each fragment of the damaged vertebral body and bone cement is injected in an amount equal to the volume of each fragment.

The disadvantages of the prototype are its inaccuracy due to the calculation of the volume of injected cement on the deformed, different from normal, vertebra and its fragments, which leads to the possibility of insufficient or excessive volume of injection of bone cement, since the volume of cement is considered equal to the volume of each of the fragments, while deformation does not necessarily occur on the _^half portion of the vertebra or fragment; the limitations of its use, as well as general contraindications for vertebroplasty for comminuted fractures of the vertebral body due to the impossibility of retaining bone cement with a high risk of its leakage outside the body of the damaged vertebra.

The technical result of the invention is to increase the accuracy of determining the volume of injected bone cement into a damaged vertebra.

The technical result is achieved due to the fact that in the method of vertebroplasty, which consists in the fact that before the operation, an image of the compression vertebra, above and below the vertebrae is obtained, the volume of cement injected is calculated, a needle is inserted into the body of the damaged vertebra under the control and the calculated before surgery is inserted the volume of cement, after which the curing of the cement is expected, before surgery, the height of the vertebral body is measured from the image obtained along the front contour of the vertebrae in the sagittal plane a, located above the compression vertebra, h _c , the height of the vertebral body located below the compression vertebra, h _n , the height of the compression vertebra h _k , as well as the length of the destroyed section of the compression vertebra m, the sizes of the compression vertebra d ₁ and d ₂ in its middle part measured in the axial plane, taking into account the fact that the vertebral body has the shape of an elliptical cylinder, where d ₁ is its semimajor axis, ad ₂ is small, the calculation of the cement volume is carried out according to the formula

Brief Description of the Drawings

The invention is illustrated by drawings (FIGS. 1-5), where in FIG. 1 shows a simplified image of the body of a deformed vertebra; FIG. 2 is a lateral radiograph of a compression fracture of the Th7 vertebral body; FIG. 3 is an axial plane tomogram image of a Th7 body; in FIG. 4 is an image of a spiral tomogram in the sagittal plane indicating the designations used, in FIG. 5 - x-ray according to the results of the operation.

Disclosure of invention

In FIG. 1 are marked: the Y and X axis are located in the axial plane, the Z axis is located in the sagittal plane, the a and b axes are in the axial plane, the height of the destroyed portion of the vertebra (height of the lost part of the vertebra) h, m is the length of the destroyed portion of the compression fracture. In FIG. 4 are denoted h _a, h _n - height of the vertebral body, measured from the front contour of the vertebrae in the sagittal disposed plane above and below the compressive vertebra respectively, h _k - Body height compression vertebra sagittal plane, measured at the anterior contour of the vertebral body to the defect site.

With a sufficient degree of accuracy for this technical solution, it can be accepted that the vertebral body has the shape of an elliptical cylinder. Large elliptical cylinder axis is equal to d _1, small - d _2, and the half-line, respectively, and ₁ = d / 2 and b = d _2/2. The plane of the boundary of the destroyed portion of the vertebra intersects the upper face of the vertebra in a straight line parallel to the X axis, m is the length of the destroyed portion of the compression vertebra (fracture) along the coordinate axis Y.

The volume of the destroyed part (in mathematical terminology - the elliptical "hoof") can be found using the triple integral

$$V={\displaystyle \underset{V}{\iiint }d\nu }$$

Passing to the triple integral, we have

,

,

and taking into account the fact that the elliptical “hoof” is symmetrical with respect to the YOZ plane, the integral takes the form

.

.

Performing integration, we obtain

You can write the resulting formula in a more compact form and express the volume through directly measured quantities d ₁ and d ₂

, $$V=\frac{h}{24m}{d}_{\mathrm{one}}^2{d}_2\left\{2{(\mathrm{one}-k^2)}^{3/2}+3k\left[k{(\mathrm{one}-k^2)}^{\mathrm{one}/2}-\arccos k\right]\right\}$$

,

, h=(h_в+h_н)/2-h_к)Where $$k=\frac{d_{\mathrm{one}}-2m}{d_{\mathrm{one}}}$$

, h = (h _in + h _n ) / 2-h _k )

h _c , h _n are vertebral body heights measured along the front contour of the vertebrae in the sagittal plane located above and below the compression vertebra, h _k is the height of the compression vertebral body in the sagittal plane, measured along the front contour of the vertebra.

The implementation of the invention

The invention is implemented as follows.

A patient with a vertebral fracture, for example in the thoracic region, is placed on the stomach. In this case, the patient’s hands are placed along the body. After laying the patient, preoperative marking is carried out taking into account the presence of distinctive signs and anatomical features of the spinal column at the level of the lesion. Under local anesthesia, a long needle (10-15 cm) with a mandrel with a beveled end at an angle of 45 ° with a diameter of 8-13G puncture the vertebral body with transpedicular access from one or both sides (according to indications, depending on the nature of the damage), while the needle should be in limits of the "oval" of the arc root. Using an electron-optical converter (EOP) of X-ray mobile operating apparatuses, X-ray control is performed. The needle is immersed in the vertebral body to the level of the anterior third. Prior to the introduction of a composite mixture into the vertebra, venospondylography with omnipack (3-5 ml) is performed. In a special vertebroplasty kit system, bone cement and solvent are mixed. In this case, tantalum dust and / or barium sulfate are added to give X-ray contrast to the bone cement. The mixture is pumped into the damaged vertebra in the volume calculated before the operation. After cement is introduced, the needle is removed. After 20 minutes, after the onset of polymerization, the patient is transported to the ward.

We give an example - an extract from the medical history.

Patient Ch., 59 years old, medical history No. 1114, was treated in the neurosurgical department of the Federal Budget State Institution of the Presidential Administration “Clinical Hospital No. 1” from 02/01/2013 to 02/11/2013 with a diagnosis of closed uncomplicated compression fracture of the body Th7 vertebra.

Complaints at admission: moderate soreness in the thoracic spine when coughing, in an upright position.

Anamnesis of the disease: 01/06/13 at about 11 a.m. rolled over by car, driver. I didn’t feel any sensations. However, running out of the car, slipped and fell, hit his back, immediately felt pain in the back (chest section). He called an ambulance team, anesthetic injection was performed (with a positive effect). In the evening, the pain intensified at home. In this state, he stayed at home until the morning (took painkillers). In the morning, the ambulance brigade was delivered to the FSBI UDP PD # 1. Somatic status and neurological examination upon admission of pathology were not revealed. Locally: soreness when tapping on the spinous processes of the Th5-Th8 vertebrae, lumbar lordosis is smoothed, hypertonicity of the paravertebral muscles of the back. On radiographs of the thoracic spine, a compression fracture of the Th7 vertebral body is determined (Fig. 2). According to the claimed method, computed tomography of the thoracic spine was performed in the axial and sagittal planes, which were used to measure the vertebral bodies (Figs. 3, 4):

d ₁ = 2a = 3.8 cm, a = 1.9 cm,

d ₂ = 2b = 2.85 cm, b = 1.425 cm,

h _s = 2.4 cm, h _n = 2.7 cm, h _k = 1.62 cm, m = 2,35 cm

h = (2.4 cm + 2.7 cm) / 2-1.62 cm = 0.93 cm,

k = (3.8 cm - 4.7 cm) / 3.8 cm = -0.237,

k ² = [(3.8 cm - 4.7 cm) / 3.8 cm ² = 0.056.

The preoperative calculation of the required amount of injected cementing material was made according to the formula:

, $$V=\frac{h}{24m}{d}_{\mathrm{one}}^2{d}_2\left\{2{(\mathrm{one}-k^2)}^{3/2}+3k\left[k{(\mathrm{one}-k^2)}^{\mathrm{one}/2}-\arccos k\right]\right\}$$

,

V = [0.93 * (1.9) ² * 1.425 / 3 * 2.35] * {2 * (1-0.056) ^3/2 +3 * (- 0.237) * [- 0.237 *

(1-0,056) ^1/2 -arccos (-0,237)]} = 3,475 (cm ³ )

The performed calculation showed that in order to achieve the proclinizing effect, it is necessary to introduce 3.475 cm ^{3 of} cementing substance. 02/08/13 performed puncture vertebroplasty of the Th7 vertebral body with the introduction of the estimated volume of bone cement. The postoperative period is smooth. Control spondylograms of the thoracic spine with an eye on the Th7 vertebra (02/08/13): a composite substance with clear uneven contours is determined in the vertebral body (Fig. 5).

As a result of the treatment, the pain syndrome regressed. Discharged in satisfactory condition under the supervision of a neurologist in a clinic.

Thus, obtaining additional images of neighboring vertebrae and measuring their parameters with the subsequent calculation of the required amount of cement ensures the achievement of the claimed technical result, which consists in increasing the accuracy of determining the volume of injected bone cement, which improves the quality of treatment of the patient.

Claims (1)

The method of vertebroplasty, which consists in the fact that before the operation, an image of the compression vertebra, above and below the vertebrae, is obtained, the volume of cement injected is calculated, the needle is placed in a pedicle transpedicularly under the control of the damaged vertebra and the volume of cement calculated before the operation is introduced, after which the cement hardening is expected, different the fact that before the operation, the height of the vertebral body located above the compression vertebra is measured according to the image obtained along the front contour of the vertebrae in the sagittal plane and, h _a, the height of the vertebral body located below the compression vertebra, h _n, the height of the body compression vertebra h _k, and the length of the destroyed portion compressive vertebra m, the dimensions of the compression vertebra d ₁ and d ₂ in its middle part is measured in the axial plane taking into account that the vertebral body has the shape of an elliptical cylinder, where d ₁ is its semimajor axis, ad ₂ is small, the calculation of the volume of cement is carried out according to the formula

Images