Congenital spinal deformities and back pain

One of the most difficult problems in assessing congenital spinal deformities is predicting their course, and therefore determining the timing and indications for surgical intervention. Perhaps the only thing that authors agree on today is that conservative treatment methods are ineffective in the case of congenital deformities. At the same time, the attitude towards early surgical treatment of congenital spinal deformities was recently diametrically opposed: thus, HG Gotze (1978) noted the "senselessness" of long-term observation of prognostically unfavorable congenital deformities, while A.I. Kazmin (1981) considered early operations for congenital scoliosis "unjustified maximalism". Constantly accumulating experience and a differentiated approach to assessing anomalies have allowed us to identify signs in each of the anatomical variants of defects that, with a high degree of probability, indicate a favorable or unfavorable course of the deformation, and, therefore, to raise the question of surgical treatment as early as possible if there are indications.

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Congenital scoliosis

Studying the natural course of congenital scoliosis, RB Winter et al. (1968) proposed using the following criteria for assessing the rate of progression of congenital spinal deformities:

• the authors considered deformation that did not change in magnitude during dynamic observation or increased by less than 1° per year as stable;
• moderately progressive scoliosis includes scoliosis that increases by 1-2° per year, which leads to a total increase in deformation over 10 years (“childhood period”) of less than 20°, i.e. does not exceed the boundaries of one classification degree;
• with rapid progression, the deformation increases by 2° or more per year. This is more than 20° during the "childhood period" and exceeds the limits of the classification degree.

In our opinion, we should talk about the progressive nature of congenital scoliotic deformity in two cases:

1. If the increase in scoliosis is proven by spondylometric methods during dynamic observation of the patient and regular X-ray control. The use of the same methods for assessing deformation in dynamics is, as noted earlier, fundamental. The rate of progression of deformation is calculated using the formula

V=>(Sc ₂ -Sc ₁ )/t,

Where V is the increase in deformation in degrees per year, Sc ₂ is the deformation value at the end of the observation period, Sс ₁ is the deformation value during the initial study, t is the duration of observation (in years).

2. If clinical examination and X-ray examination reveal signs that indicate with a high degree of certainty an unfavorable course of the deformation.

For many years, the prognosis of the course of congenital scoliosis caused by a violation of the formation of vertebrae was based on the determination of the X-ray anatomical variant of the hemivertebra, or more precisely, the type of its segmentation. According to I. A. Movshovich (1964), RB Winter, JH Moe, VE Eilers (1968), each completely segmented vertebra, including an abnormal one, has two apophyseal growth zones - cranial and caudal. In their opinion, the number of apophyseal growth zones in a completely segmented hemivertebra on the convex side of the deformation will be two more than on the concave one, which should lead to an asymmetry in the growth of the right and left halves of the spine and to an increase in the deformation. With a semi-segmented hemivertebra, the number of apophyseal growth zones on the convex side of the deformation will be the same as on the concave one, and with a non-segmented one - even less. Thus, fully segmented or "active" hemivertebrae should be prognostically unfavorable, congenital deformations with them should be progressive. At the same time, scoliosis with non-segmented hemivertebrae should be non-progressive. The prognosis regarding the course of scoliosis with semi-segmented hemivertebrae, according to the authors, remains uncertain.

The gradual increase in the number of observations of patients with congenital scoliosis made us skeptical about the prognostic reliability of the sign of segmentation of the hemivertebra. Moreover, the use of MRI in the diagnosis of congenital deformities has called into question the very radiological concept of segmentation. At present, quantitative indicators calculated from radiographs using mathematical methods have acquired greater prognostic significance in assessing the dynamics of deformations.

To predict the course of congenital scoliosis caused by disturbances in the formation of vertebral bodies, the activity index of the hemivertebra, the progression index of congenital deformity and the coefficient of total dysplasia are used.

The activity index of the hemivertebra (IIa) is calculated based on the ratio of the distances between the roots of the arcs of the vertebrae in contact with the abnormal one, measured on the convex and concave sides of the deformation. An increase in the index during the study of radiographs in dynamics indicates an increase in the wedge shape of the hemivertebra and, accordingly, an increase in the deformation.

The index of progression of deformation (IP) is measured by the ratio of the magnitude of the scoliotic arc to the angle of wedge-shapedness of the apical (semi-vertebra) ("semi-" is taken in brackets, since the index can also be calculated in relation to wedge-shaped vertebrae). The index of progression reflects not so much the nature of the anomaly, as the degree of compensation of the deformation due to the sections in contact with the abnormal vertebra. In case of compensated non-progressive deformation, the index value should be less than or equal to 1.0, in case of progressive (decompensated) deformation - exceed 1.0. Progressive course of congenital scoliosis, accompanied by the value of IP> 1.0, is often observed in cases where congenital deformation occurs as idiopathic (dysplastic) scoliosis.

The coefficient of total dysplasia (Ced) takes into account not only the nature of the apical anomaly, but also changes in all vertebrae included in the arc of deformation, which may also be dysplastic.

To assess the progression of congenital scoliosis with vertebral segmentation disorders, by analogy with the hemivertebra activity index, a growth asymmetry index was proposed. Its increase in dynamics also indicates the progression of deformation.

In order to identify the most unfavorable signs of congenital scoliosis progression, we conducted a polyfactorial analysis, which allowed us to identify quantitative and qualitative indicators that with a high degree of probability indicate a possible increase in deformation and, therefore, to recommend in these cases a more active treatment tactic already at the patient's initial visit. Thus, the presence of the signs given in the table indicates a prognostically extremely unfavorable course of congenital scoliosis - its rapid progression is noted with a probability exceeding 70%.

In case of vertebral formation disorders, we calculated the probability of rapid progression of congenital scoliosis depending on the initial magnitude of scoliotic deformation and the degree of severity of pathological rotation of the spine.

Signs of a high probability of rapid progression of congenital spinal deformities

In case of violation of the formation of vertebrae	The presence of a kyphotic component of the deformity (the probability of progression is close to 90%). Unilateral arrangement of 2 or more semi-vertebrae at the apex of the arch. The initial deformation value is more than 30°. The presence of pronounced pathological rotation (2 or more degrees according to the pedicle method). The presence of different sided semivertebrae, located more than 3 segments apart. The value of the hemivertebra activity index is > 2.3. The value of the deformation progression index is > 1.1.
In case of violation of vertebral segmentation	Any kyphosis variant of the defect. Segmentation violation of the "blocking through segment" type. The initial deformation value is more than 30°. Thoracolumbar localization of the defect. The value of the asymmetry index is >1.3.
For mixed vices	The combination of any mutually aggravating variants of defects is prognostically unfavorable.

The probability of rapid progression of scoliotic deformation depending on its initial magnitude

Initial magnitude of scoliosis	The likelihood of rapid progression
Less than 30°	16%
30-50°	70%
More than 50°	100%

The probability of rapid progression of deformation depending on the degree of pathological rotation (torsion)

Torsion degree according to pedicle-method	The likelihood of rapid progression
0-1 st II-IV st.	15% 80%

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