Anomalies and malformations of the spine

The practice of manual therapy forces radiologists to pay attention to all the details and structural features of the spine of each patient. And in this sense, anomalies in the development of the vertebrae play an important role. This article discusses only the most common developmental anomalies encountered by the radiologist almost daily.

Numerous classifications of malformations and anomalies of the spine are based on the experience of leading surgical clinics. They are useful for surgeons and radiation diagnosticians in terms of a general understanding of the processes of embryogenesis and ontogenesis of the spine. The practice of working with chiropractors shows that it is much more important to know those anomalies that do not require surgical intervention, but must be taken into account to analyze the spatial position of the vertebrae. Developmental anomalies help the radiologist to explain why scoliosis occurred, where early osteochondrosis came from in this patient precisely in these vertebral motor segments.

Anomalies and malformations have a significant effect on the statics of the spine as a whole and movement in each spinal motion segment. Malformations are often multiple. In 88% of cases, they are found along the entire length of the spine, and on average, one patient had five malformed vertebrae [Ulrich E.V., 1995].

The most common changes in the number of lumbar and sacral vertebrae. Sacralization of the fifth lumbar vertebra occurs when the transverse processes become large and form an anatomical connection with the sacrum and ilia of the pelvis, which is bone, cartilaginous, in the form of a joint; fixed or mobile. In the latter case, it can cause pain. Functionally, only four vertebrae remain in the lumbar spine [Maikova-Stroganova VS, Finkelstein MA, 1952]. Sacralization of the fifth lumbar vertebra was observed in skeletal studies in 8.1% of cases, unilateral in 5.8% and bilateral in 2.3%. [Dyachenko V.A. 1954].

The opposite situation occurs when lumbarization of the first sacral vertebra occurs. It does not fuse with the sacrum, forming into a free vertebra. In this case, six vertebrae function in the lumbar region. Lumbarization of the first sacral vertebra occurs in 1.1% of skeletons. The process can be unilateral, when one of the transverse processes grows larger than the other, which creates conditions for scoliotic deformity of the spine. PL Zharkov proposes to classify the types of sacralization and lumbarization according to the nature of the influence of this type of dysplasia on the static and dynamic function of the spine. The author distinguishes 1) bone (two-sided,
one-sided), 2) cartilaginous (two-sided, one-sided), and articular (two-sided, one-sided) forms of dysplasia [Zharkov PL, 1994].

The asymmetric position of the articular areas of the vertebrae is called a tropism anomaly. One of the articular processes takes the usual position, closer to the sagittal plane, and the second extends with its longitudinal axis into the frontal plane. Anomalies of the tropism of the thoracic, lumbar and sacral regions occur (on the skeletons) in 33% of cases [Dyachenko V.A. 1954]. Shortening of the articular processes was found in 19%. Complete non-closure of the vertebral arches (Spina bifida posterior) occurs in 19% of cases. Most often, this developmental anomaly occurs in the first sacral vertebra 5 – 10%. An open sacrum canal (S1-S5) is found in 3.6% of cases, [Dyachenko V.A. 1954; Ulrich E.V., 1995]. Non-confusion of the vertebral bodies (Spina bifida anterior) is most often found in the thoracic region, reaching 5.28% [Dyachenko V.A. 1954; Ulrich E.V., 1995]. Congenital bilateral non-closure of the arch (spondylolysis) is more common in the fifth lumbar vertebra and is 4.5-5%. Violation of the number of ribs can have a significant impact on the statics of the spine. Thus, the formation of additional ribs, especially asymmetric ones, can lead to scoliosis. Cervical ribs are formed from 0.5-1.5% (according to Dyachenko V.A. 1954) to 7% (according to Maykova-Stroganova V.S., Finkelstein M.A., 1952) of patients, lumbar in 8-9 %.

Underdevelopment (hypoplasia) or complete absence (agenesis) of XII ribs occurs in 0.5-0.9% of cases. Restrictions on the mobility and functioning of the chest are often associated with variants of rib development (cleavage, synostosis, exostosis, doubling, rib concretion, etc.), which are found in 0.5-1% of patients. Particular importance is attached to the developmental anomalies of the vertebrae of the craniovertebral zone. In the studies of M.K. Mikhailov (1983), they were found in 8% of the surveyed. Non-closure of the posterior arch of the first cervical vertebra occurs in 1.3% of patients, blockage (concrescence) of the second – third cervical vertebrae in 2%, and complete assimilation of the first cervical vertebra and occipital bone in 1-2% of skeletons. For vertebrologists, it is of interest to identify the assimilation of the atlas, that is, its adhesion to the occipital bone (occurs in 1-2%), saddle hyperplasia of the atlas [Maykov-Stroganova VS, Finkelstein MA, 1952; Dyachenko V.A. 1954; Korolyuk I.P., 1996; Ulrich E.V., 1995].

The transformation of the sulcus of the vertebral artery located on the atlas into a canal due to the formation of a bone bridge above this sulcus (Kimmerle anomaly). The medial position of the bone bridge is distinguished, when it connects the articular process and the posterior arch of the atlas, and the lateral one, if the bridge is thrown between the joint and the costo-transverse process of the atlas, forming an abnormal ring lateral to the articular process.
Kimmerle anomaly occurs in 3% of cases and can play an important role in the development of dyscirculatory disorders in the basin of the vertebral arteries [Lutsik AA, 1997; Ulrich E.V., Mushkin A.Yu., 2002].

Klippel-Feil-Sprengel syndrome is a severe congenital anomaly of the cervical spine with its sharp shortening, limited mobility and concretion of several vertebrae. A variety of anomalies are determined radiographically: butterfly-shaped vertebrae, posterior or lateral hemivertebrae, concretion or non-fusion of its individual parts [Lagunova IG, 1989; and etc.].

Spondyloepiphyseal dysplasias are characterized by changes in the shape of the vertebral bodies of the type of platysondilia, most pronounced at the Th8 – L3 level. The cause of these manifestations is a violation of enchondral ossification in all parts of the skeleton, where spongy bone is formed. The vertebra acquires an elongated shape and resembles a bottle directed neck forward, which is called the “central tongue” in the literature. Spondyloepimetaphyseal dysplasias are characterized by a decrease in the height of the anterior sections and the convergence of the bodies of the thoracic vertebrae.


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