Compression splinter fractures of lumbar vertebral bodies: causes, symptoms, diagnosis, treatment

Compression comminuted fractures of the lumbar vertebral bodies are an independent and more severe clinical form of fractures of the lumbar vertebral bodies. Unlike compression wedge fractures, they are always accompanied by damage to adjacent intervertebral discs and fragmentation of the vertebral bodies into separate fragments. By their nature, these injuries are classified as stable injuries.

Compression comminuted fractures of the lumbar vertebral bodies account for 14.7% of all lumbar spine injuries and 19.9% of compression wedge fractures of the lumbar vertebral bodies.

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What causes lumbar vertebral compression fractures?

These injuries of the vertebral bodies occur with a strictly defined - compression mechanism of violence, i.e. in cases where the crushing force acts vertically and the vertebral bodies are located in a vertical line. Such an arrangement of the lumbar vertebral bodies is possible in cases where the lumbar spine is in a position of moderate flexion and the lordosis characteristic of this section of the spine disappears. Most often, compression comminuted fractures are localized in the region of the first and third lumbar vertebrae. Fractures occur when falling on straightened legs or buttocks with slight flexion of the lumbar region or when significant weights fall on the shoulders or back of the victim, who is in a position of slight inclination. A. G. Karavanov (1946) described a similar injury to the first lumbar vertebra in a gunner-radio operator during a dive of an airplane. Such fractures are also possible during ejection.

For a long time it was believed that compression comminuted fractures of the lumbar vertebral bodies occur with excessive flexion of the spine and only quantitative features of violence lead to the occurrence of these injuries. In 1941, Lob first put forward and substantiated the theory of the "explosive" force of the disc in the origin of these injuries. He emphasized that the explosive force of the disc depends on the height of the intervertebral disc. The mechanism of occurrence of compression comminuted fractures was studied in detail by Roaf (1960) and in our clinic by E. A. Kovalenko (1965).

According to Roaf, when vertical violence is applied to the lumbar spine straightened in a vertical direction, there is initially a significant bending and protrusion of the cranial end plate into the body and a slight protrusion of the fibrous ring forward without changing the shape of the nucleus pulposus. Due to the resulting increase in intravertebral pressure, blood leaks from the vertebral bodies into the paravertebral space, which is accompanied by a significant decrease in arterial pressure (the "shock-adsorption" mechanism). The subsequent action of violence creates increasingly significant pressure on the cranial end plate and ultimately leads to its rupture. The nucleus pulposus rushes into the defect of the plate, which, according to the laws of the hydraulic effect, tears the vertebral body into separate fragments. As a rule, the degree of compression of the vertebral bodies with this mechanism is insignificant, since the entire force of the violence is spent on rupturing the body.

Thus, compression comminuted fractures of the lumbar vertebral bodies, both by the mechanism of occurrence and by morphological changes, represent a special injury to the spine. The features of this injury consist of severe fragmentation of the vertebral body into separate multiple fragments, among which there are usually two largest - anterior and posterior. As a rule, a rupture of adjacent intervertebral discs and interposition of the substance of the damaged discs between the two main fragments occurs. The possibility of displacement of the posterior fragment towards the spinal canal and significant hemorrhage can cause complications from the spinal cord. The severity of the damage to the bone substance of the vertebral body negatively affects its regenerative capabilities. Healing of such a fracture lasts much longer than healing of a usual compression wedge-shaped fracture of the body.

Symptoms of lumbar vertebral compression fractures

Clarification of the circumstances of the injury and clarification of the mechanism of violence allow us to suspect the presence of a compression comminuted fracture of the lumbar vertebral body. The main clinical symptoms are similar to the clinical manifestations of compression wedge-shaped fractures of the lumbar vertebral bodies. However, the intensity and severity of these symptoms are much more pronounced.

The victim's complaints and the data of objective clinical examination are similar to those described for compression wedge fractures of the lumbar vertebral bodies. The general condition of the victims is severe, more often one can note the phenomena of mild shock, pallor of the skin and mucous membranes. Significantly more often one observes the phenomena of irritation of the peritoneum, intestinal paresis, urinary retention. This is explained by a much larger volume of retroperitoneal hemorrhage. In these injuries, sometimes an emergency laparotomy is performed due to suspected damage to internal organs. The typical position of the victim is on the side with the hips bent and brought to the stomach.

Neurological symptoms of lumbar vertebral compression fractures are observed in 88.2% of victims with lumbar vertebral compression fractures. It is important to note that in victims with lumbar root compression fractures treated conservatively, worsening of neurological symptoms is almost inevitable. Some victims who have minor or no neurological manifestations in the acute period sometimes develop severe radicular or spinal disorders in the long term.

Diagnosis of compression comminuted fractures of the lumbar vertebral bodies

Two typical projections usually give a comprehensive idea of the nature of the damage. In this case, a very typical and unique picture emerges.

The lumbar spine is straighter than normal. This is determined by the clarity of the intervertebral spaces in the lower lumbar spine. This emphasizes the location of the spinous processes at all levels - they are more centered in relation to the shadows of the vertebral bodies. The lateral marginal bodies of the broken vertebra extend beyond the lateral contours of the bodies of the adjacent lumbar vertebrae, the broken body appears wider in cross-section. A decrease in the height of the intervertebral spaces adjacent to the broken body is noted. No decrease in the height of the vertebral body is observed. It only seems less high than the adjacent bodies due to an increase in its transverse diameter.

The profile spondylogram shows an increase in the anteroposterior size of the fractured vertebral body. Its ventral surface extends beyond the anterior margin of the remaining vertebral bodies. The posterior contour of the fractured vertebral body is displaced posteriorly - toward the spinal canal and to a greater or lesser extent deforms the straight line forming the anterior wall of the spinal canal. The cranial and caudal endplates of the body are interrupted, their integrity is compromised. Between the anterior and posterior fragments of the fractured body, a gap is visible, displaying the fracture plane on the spondylogram. Sometimes such a gap is not visible due to the mismatch of the fracture plane with the central ray. In this case, it is revealed by an area of enlightenment of irregular shape with unclear contours. The anterior fragment of the fractured vertebral body can be equal to half of the body, but not so rarely it makes up one third of it. As a rule, smaller fragments of the fractured vertebra are not determined on the spondylogram. The lateral spondylogram clearly shows a decrease in the height of the adjacent intervertebral spaces. In some cases, a decrease in the height of the anterior fragment can be observed.

This is the most typical radiographic picture of compression comminuted fractures of the lumbar vertebral bodies.

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Treatment of compression comminuted fractures of the lumbar vertebral bodies

The preservation of the ligamentous apparatus, in particular the anterior and posterior longitudinal ligaments, in compression comminuted fractures gives a number of authors the right to speak out in favor of conservative treatment, which consists of one-stage forced reduction followed by immobilization for 3-4 months (Holdswortli) - 9-12 months (A.V. Kaplan).

The technique of forced one-stage reduction is similar to that described by us in the treatment of compression wedge fractures.

The duration of wearing the corset is dictated by the time of the onset of spontaneous anterior bone block due to calcification of the anterior longitudinal ligament.

Conservative treatment with the outcome in spontaneous anterior bone block often does not bring recovery to the victim. As numerous findings in the process of surgical interventions for old compression comminuted fractures of vertebral bodies have shown, the cause of pain and other complications even with the onset of anterior spontaneous bone block is the interposition of the masses of torn discs between the fragments of the broken body. The presence of such interposition leads to the fact that only the anterior fragment of the broken vertebra is fused with the bodies of adjacent vertebrae. The posterior fragment, the most functionally responsible one, remains mobile. The presence of a mobile fragment, as well as the remains of damaged discs, are the cause of pain and other late complications. Therefore, posterior spondylodesis is also ineffective in these cases.

Partial vertebral body replacement surgery

The indication for partial resection of the fractured vertebral body with subsequent anterior spondylodesis of the partial replacement type is the presence of a compression comminuted fracture of the vertebral body.

The objective of the surgical intervention undertaken is to create conditions for the onset of an anterior bone block between the posterior fragment of the body of the broken vertebra and the bodies of adjacent vertebrae with the elimination of the existing interposition of the masses of torn intervertebral discs; removal of the remains of damaged intervertebral discs; restoration of the normal height of the damaged anterior spine and normalization of the anatomical relationships in the posterior elements of the vertebrae.

The earlier the intervention is performed, the technically easier and simpler it is to perform. The time of intervention in each individual case depends on the condition of the victim, the degree of expression of the general phenomena of the previous injury, the presence or absence of concomitant injuries. In the absence of contraindications, the optimal time for surgical intervention is 5-7 days from the moment the injury occurs.

The best method of pain relief is endotracheal anesthesia with muscle relaxants. Muscle relaxation and spontaneous breathing shutdown achieved with this type of pain relief significantly facilitate the technical performance of the operation. Timely, thorough and meticulous replacement of blood loss is mandatory.

The position of the victim on the operating table depends on the chosen surgical approach.

Existing surgical approaches to the lumbar vertebrae can be divided into three groups: posterior and postero-external, anterior transperitoneal, anterior and anterior-external extraperitoneal approaches.

The posterior approach is most widely used in orthopedics and traumatology. This approach creates sufficient space for manipulations on the spinous, transverse and articular processes, as well as the arches of the lumbar vertebrae.

The postero-external approach (lumbotransversectomy) is widely used by phthisiatric surgeons for radical intervention on the lesion in lumbar tuberculous spondylitis. Our experience confirms the opinion that this surgical approach allows only "minor" interventions on the vertebral bodies, such as curettage of the lesion, biopsy, since it does not create sufficient space for manipulations and does not allow visual control over them. Some surgeons use the anterior transperitoneal surgical approach. According to Hensell (1958), this approach has not become widespread due to frequent complications in the form of dynamic intestinal obstruction and thrombosis of the mesenteric vessels. In 1932, V.D. Chaklin proposed a left-sided anterior-external extraperitoneal approach to the lower lumbar vertebrae. Subsequently, this approach was modified for the upper lumbar vertebrae. Hensell (1958) described an anterior extraperitoneal approach performed through a paramedian incision.

The optimal surgical approaches are as follows.

1. The anterior extraperitoneal paramedian approach is used to access the lumbosacral spine and lumbar vertebrae, including the caudal part of the second lumbar vertebra.

Anterior-external extraperitoneal left- and right-sided access according to V.D. Chaplin can also be used for these sections of the spine. The disadvantages of V.D. Chaklin's approach are its high traumatic nature.

2. If manipulations are necessary on the 2nd lumbar vertebra and on the 1st lumbar intervertebral disc, including the caudal part of the body of the 1st lumbar vertebra, a left-sided extraperitoneal anterior-external approach with resection of one of the lower ribs is used.

If necessary, this surgical approach can easily be converted into an extraperitoneal transthoracic approach, allowing simultaneous manipulations on both the lumbar and thoracic spine.

3. To the first lumbar vertebra, if it is necessary to perform manipulations on the cranial section of the second lumbar vertebra and the body of the second lumbar vertebra - transpleural access with diaphragmotomy. In some individuals, this surgical access allows for intervention on the cranial section of the third lumbar vertebra.
4. Transpleural surgical access to the lower thoracic, middle and upper thoracic vertebrae, both right- and left-sided.

Vertebral manipulations. One of the surgical approaches is used to expose the body of the fractured vertebra and adjacent damaged intervertebral discs. For convenient manipulation of the vertebrae, it is necessary that the body of the fractured vertebra, the intervertebral disc and the caudal half of the overlying vertebra, the intervertebral disc and the cranial half of the underlying vertebra are completely exposed. Large blood vessels are displaced and protected with wide curved elevators inserted between the anterior longitudinal ligament and the prevertebral fascia. It is necessary to periodically release the tension of the vessels to restore normal blood flow in them. Usually, the paravertebral tissues are immobilized with blood that has spilled out at the time of injury. The anterior longitudinal ligament can be longitudinally stratified, but is never torn in the transverse direction. Usually, torn intervertebral discs lack their inherent turgor and will not stand out in the form of characteristic ridges. At the level of the third lumbar vertebra, the fibers of the left median crus of the diaphragm are woven into the anterior longitudinal ligament. The crus of the diaphragm is sutured with a provisional ligature and cut off. It should be remembered that the renal artery passes along its medial edge. Two pairs of lumbar arteries and veins passing along the anterior surface of the vertebral bodies are isolated, ligated and dissected. The anterior longitudinal ligament is dissected in an apron-like manner and folded back to the right on the right base. Its incision is made along the left lateral surface of the body of the fractured vertebra, the adjacent intervertebral disc, the caudal half of the overlying vertebra and the cranial half of the underlying vertebra, parallel to and slightly inward from the border sympathetic trunk. It should be remembered that the anterior longitudinal ligament is intimately connected with the vertebral bodies and freely throws over the intervertebral discs.

After separating and folding the anterior longitudinal ligament to the right, the anterolateral surface of the vertebral bodies is exposed. The fragments are removed with tweezers. Usually there is one large fragment of the anterior part of the body of the broken vertebra, under which there are smaller fragments, fibrin clots, interposed masses of intervertebral discs. Bone fragments are removed quite easily, they are connected to the vertebra only by fibrous tissues. Depending on the nature of the injury, a larger or smaller part of the broken vertebra is removed. Often, only the lateral and posterior parts of the broken vertebra remain. Torn discs must be completely removed. The caudal plate of the overlying vertebra and the cranial plate of the underlying vertebra are removed. After removal of all damaged tissues, a rectangular defect is formed, the walls of which are the posterior and lateral parts of the broken vertebra, the caudal and cranial surfaces of the bodies of adjacent vertebrae. All of them are formed by bleeding spongy bone. If appropriate, anterior decompression can also be performed by removing the posterior portion of the fractured vertebra.

The need for anterior decompression occurs in complicated fractures. The posterior fragment of the broken vertebra is displaced backwards and, deforming the spinal canal, causes compression of the spinal cord. In these cases, the posterior fragment of the broken body protruding into the lumen of the spinal canal is removed under visual control and an operation to completely replace the vertebral body is performed.

Postoperative management

After the operation, the victim is placed in a bed with a shield in a supine position. He is given a position of moderate flexion. This is achieved by slightly bending the legs at the knee and hip joints on a roller placed under the knee joint area. The victim spends the first 10-12 days in this position. Subsequently, he is placed in a pre-made back plaster bed that repeats the normal physiological curves of the spine. The victim remains in this bed for 3-4 months. Lumbar lordosis can also be formed using the hammocks described earlier.

Intravenous fluid infusion (blood, polyglucin) is stopped after arterial pressure has stabilized. According to indications, painkillers, cardiac drugs, and oxygen are administered. Extubation is performed after spontaneous breathing has been restored. Usually, all parameters return to normal by the end of the operation or in the next few hours after its completion. In the postoperative period, antibiotics are recommended.

After 24 hours, the rubber tubes inserted into the subcutaneous tissue are removed. Intestinal paresis and urinary retention may occur.

Usually by the end of 2 - beginning of 3 days the condition of the victim improves. After 3-4 months a large plaster corset is applied. The victim is discharged for outpatient treatment. After 4-6 months the corset is removed. By this time the bone block between the broken and adjacent vertebrae is already determined radiologically.

It should be borne in mind that on an X-ray, usually only the cortical part of the transplant is clearly visible, and its large spongy part is lost in the mass of the vertebral bodies.

Thus, early primary surgical treatment of victims with closed compression crushed penetrating fractures of the lumbar vertebral bodies, carried out according to the method proposed by us and described above, gives a good effect. With the help of the intervention, conditions are created for the fastest onset of bone block. Removal of damaged discs excludes the possibility of late complications from the spinal cord elements. Partial, and if necessary, complete replacement of the body of the broken vertebra allows maintaining the normal height of the non-native damaged segment of the spine and prevents the possibility of developing axial deformation of the spine. The onset of bone fusion in the area of the damaged and adjacent vertebrae excludes the occurrence of subsequent functional failure of the spine.