METHOD FOR DIAGNOSTICS OF THE SPINAL MOTION SEGMENT INSTABILITY IN OSTEOCHONDROSIS OF CERVICAL SPINE

Introduction. Instability — dislocation of the vertebrae, one of the forms of the motor segment dysfunction, causes pain and subsequent neurological disorders. There is a direct relationship between the data of the instability indicator and the clinical picture: the higher it is, the more pronounced the clinical manifestations of vertebral displacementare. And vice versa, conversely, its zero value (there is a functional block) coincides with rare exacerbations of the pain syndrome and a relatively satisfactory condition of the patient. Various types of vertebrae dislocation are much more common than is determined by functional radiography of the spine. As a rule, cervical dislocations are diagnosed already at a later date, when conservative measures are difficult and ineffective, and high-tech surgical treatment is requiring with certain material costs. Aim. To study the effectiveness of the developed method of functional radiography with weights for diagnosing instability of the spinal motion segment in the cervical spine. Materials and methods. 50 patients were under observation, the average age was 50.6 ± 2.19 years. All patients were admitted to the neurosurgical department of the clinic of the Irkutsk Scientific Center for Surgery and Traumatology with a diagnosis of adult osteochondrosis of spine (ICD M 42.1). Results. A comparative analysis of the study results of the effectiveness of X-ray methods for diagnosing instability of the spinal motion segment in the cervical spine revealed that the method of weight-bearing spondylography, where the percentage of verification was 68 %, was the most sensitive one. We have developed a formula for determining instability in the spinal motion segment: z = a + b · x – c · l, where z — indicator of instability of determined spinal motion segments; x — patient’s age; l — length of the cervical spine — the distance from the condyle of the lower jaw to the upper contour of the spinous process of the first thoracic vertebra — ThI, a, b, c — coefficients of linear dependence, obtained by the method of least squares by experimental-calculation (software-computing complex Table Curve 3D v4.0.01). The cervical dislocation was measured when the patient's neck was bent 45° forward (flexion) and 15° backward (extention). The obtained data were grouped according to the sex of the patients, and displacement of the vertebrae. This relationship shows that the maximum normal strain of the intervertebral discs is manifested at a neck flexion of 45°, extension of 15°, and with a load of 500 g, mounted on the patient’s head. A correlation between the length of the cervical spine and the age of patients was established, the correlation coefficient was rix = 0.58. The correlation dependence of the index of the cervical vertebrae instability and the age of patients was checked, the correlation coefficient was rix = 0,58. Correlation coefficients show a fairly high correlation between the length of the cervical spine and age of patients, the index of instability of the cervical vertebrae and age of patients, the index of instability of the cervical vertebrae and length of the neck of patients. The values of the coefficients used in the proposed formula are a = 11.13; b = 0.11; c = 0.45 were obtained by the least squares method experimentally and calculated based on a mathematical analysis of the results of studies of 50 patients. Conclusion. The method of functional weight-bearing spondylography makes it possible to reliably detect instability of the spinal motion segment, while the percentage of verification was 68%. The proposed formula of mathematical calculation helps to clarify the index of instability of the cervical spinal motion segment and can be used in practical work.