Thoracic and Lumbar Compression Fractures

Abstract

Thoracolumbar spine fractures are relatively uncommon accounting for only 0.6–3% of all pediatric fractures. Mechanism dictates the injury pattern. Compression fractures typically occur as a result of axial loading from a fall. When the fall occurs with a forward flexed trunk, the majority of force is transmitted to the anterior column of the vertebral body. This force fractures the anterior column of the vertebral body and causes a wedge deformity. If the trunk is more extended, the vertebral body will be loaded more symmetrically, and the force through the body may be dissipated in a more radial fashion leading to a burst fracture. Careful physical examination is critical in these patients to rule out the possibility of neurologic involvement or associated injuries. Initial evaluation with anteroposterior (AP) and lateral supine x-rays is typically sufficient to diagnose a compression fracture. If the diagnosis is in doubt, advanced imaging is helpful. Computerized tomography (CT) scans can confirm the presence of a suspected fracture. Magnetic resonance imaging (MRI) will show edema beneath the superior endplate, suggestive of an acute fracture, and also allows evaluation of the posterior ligamentous structures. In the absence of a significant kyphotic deformity, compression fractures are treated nonoperatively with a brief period of brace immobilization. In the pediatric population, the vertebral wedge deformity may reconstitute owing to the long-term remodeling potential of the vertebral body.

1 Brief Clinical History

A 10-year-old male sustained a fall off of the monkey bars landing directly on his backside. Immediately after the fall, he noted mid-thoracic back pain without radicular symptoms. He denied loss of consciousness or injury elsewhere. Upon examination, he was neurovascularly intact without motor or sensory deficits. Bony tenderness to palpation in the midportion of the thoracic spine was present without obvious bony step-off. There was no interspinous tenderness. No pathologic reflexes were present. Initial radiographs (Fig. 1a–c) demonstrated slight wedging of the superior endplate of T7 suggestive of a compression fracture. To confirm the suspected diagnosis, a non-contrast MRI of the neural axis was attained. Edema was noted under the superior endplate of T7 confirming the suspected diagnosis of a compression fracture (Fig. 2). The patient was admitted for pain control and fitting of an orthosis.

Fig. 1

(a–c) Injury presentation AP and lateral radiographs. The affected T7 vertebra is highlighted by the red arrow in (b) and (c). The sagittal index for the T7 vertebra was 0.810

Fig. 2

Sagittal STIR MRI demonstrating edema beneath the superior endplate of T7 confirming the diagnosis of a compression fracture. No ligamentous involvement posteriorly is noted

2 Preoperative Clinical Photos and Radiographs

See Figs. 1, 2, and 3.

Fig. 3

Non-contrast CT scan of another patient who was in a motor vehicle collision and complained of thoracolumbar back pain. The CT scan demonstrates disruption of the superior endplates of the T11 and T12 vertebra with slight wedging of these vertebrae. The patient was diagnosed with two compression fractures and treated with a TLSO for 6 weeks

3 Preoperative Problem List

T7 compression fracture with minimal wedging and loss of height.

4 Treatment Strategy

In the pediatric population, compression fractures can almost universally be treated nonoperatively. The mainstay of treatment is immobilization with an orthosis and pain control. This patient was admitted to the hospital for pain control and fitting of a custom orthosis. In the past, the use of a hyperextension (Jewett-type) brace was commonplace. At the author’s institution, children with simple compression fractures are placed into a custom-molded thoracolumbar spinal orthosis (TLSO) molded into slight extension. The child is permitted to ambulate freely with the brace and is discharged once pain is controlled. Owing to the stable nature of the fracture, the orthosis is not worn for sleeping.

The patient was advised to wear his TLSO for a total of 6 weeks. X-rays were taken at 2- and 6-week follow-up appointments to confirm that no additional kyphosis developed at the fracture site (Figs. 4a, b, and 5). At the 6-week visit, the patient was pain-free. Six additional weeks of activity restriction was recommended to allow definitive consolidation at the fracture site. Three months after his injury, the patient was returned to full activity without restriction.

Fig. 4

(a–b) Upright AP (a) and lateral (b) x-rays 2 weeks after injury. These films were taken out of the TLSO. The degree of wedging at the T7 vertebra is unchanged from the initial injury films

Fig. 5

Lateral x-ray at 6 weeks out of the TLSO demonstrates maintenance of the anterior height of T7 without interval wedging or kyphosis. The patient was pain-free at this visit, and the TLSO was discontinued

5 Basic Principles

• 1. Compression fractures occur as the result of an axial loading injury to the spine with the trunk in flexion (Newton and Luhmann 2015). The higher water content of the nucleus pulposus in the immature spine allows the disc to act as more of a shock absorber thereby lessening the risk of bony injury (Akbarnia 1999).

• 2. By definition, only the anterior column of the vertebral body is involved in a compression fracture. This means the posterior portion of the endplate remains intact. The superior endplate will be involved twice as often as the inferior endplate. Even with 50% compression of the vertebral body, involvement of the posterior ligamentous structures is rare (Akbarnia 1999).

• 3. Compression of the vertebral body can occur in both the coronal and sagittal planes. Lateral compression causes a mild scoliosis that is stable and nonprogressive (McPhee 1981; Pouliquen et al. 1997).

• 4. The sagittal inde x as described by Gaca et al. can be used to distinguish a true compression fracture from the physiologic wedging often present in the thoracic and lumbar spines of children and adolescents (Gaca et al. 2010). These authors suggested that if the ratio of the height of the anterior portion of the vertebral body to the posterior portion was less than 0.893, the compression was unlikely to be physiologic. MRI (Fig. 2) and CT scans (Fig. 3) can be used to confirm a suspected compression fracture.

• 5. The goal of treatment is to prevent progression of the kyphotic deformity caused by the anterior wedging of the vertebral body. Fractures with less than 40° of acute wedging can be treated conservatively (Newton and Luhmann 2015).

• 6. The use of an orthosis for 6 weeks provides sufficient support for fractures amenable to conservative treatment. Either a TLSO or Jewett brace may be utilized (Akbarnia 1999; Newton and Luhmann 2015; Singer et al. 2016). Advising an additional 6 weeks of activity restriction after bracing prevents reinjury.

• 7. Fractures with substantial kyphotic deformity exceeding 40° at either a single level or across multiple levels can be treated with a posterior spinal fusion (Newton and Luhmann 2015).

• 8. The more skeletally immature the patient is at the time of injury, the greater the potential for remodeling of the vertebral body. Patients younger than 12 or those with a Risser sign less than 2 are likely to reconstitute the majority of their vertebral height over time (Magnus et al. 2003; Singer et al. 2016). Some authors have suggested that disruption of the vertebral end plate may lead to early disc degeneration, the significance of which is not known (Kerttula et al. 2000).

6 Images During Treatment

See Fig. 4.

7 Technical Pearls

• 1. The level of the fracture should determine the type of orthosis utilized. Fractures at the T6 level and above require extension of the brace to include the cervical spine (CTLSO or Minerva-type brace) in order to provide adequate immobilization. Thoracic compression fractures from T7 distally and lumbar fractures may be treated with a TLSO. Isolated lumbar compression fractures can be treated in a lumbosacral orthosis (LSO).

• 2. Molding the TLSO into slight extension at the fracture site may provide additional pain relief and theoretically guards against worsening of an acute kyphotic deformity.

• 3. The author typically takes upright spine x-rays out of the brace 2 weeks after injury. Given the inherent stability of a compression fracture, removing the brace briefly for the x-ray is acceptable and allows better imaging of the affected vertebra.

• 4. Full-length scoliosis films are preferred when evaluating these injuries to allow for adequate determination of sagittal balance.

8 Outcome Clinical Photos and Radiographs

See Figs. 5 and 6.

Fig. 6

(a–c) AP (a) and lateral (b) x-rays of a 17-year-old male who presented to the clinic with the insidious onset of mid-thoracic back pain without recent trauma. No neurologic symptoms were present. In the absence of trauma, the presence of an apparent compression fracture at T6 was concerning. MRI (c) revealed a pathologic burst fracture at T6 with focal kyphosis. No substantial spinal cord compression was noted. Increased signal was seen in the T10–T12 vertebra. Further workup revealed the presence of multiple metastatic lesions throughout the body. The patient was ultimately diagnosed with metastatic alveolar rhabdomyosarcoma after biopsy of a pelvic lesion

9 Avoiding and Managing Problems

• 1. Patients with multiple consecutive compression fractures are at a higher risk for developing a kyphotic deformity. Consideration should be given to monitoring these patients more frequently with radiographs or extending the duration of bracing.

• 2. Activity restriction for 6 weeks after discontinuation of bracing lessens the risk of reinjury. Upon diagnosis, all patients in the author’s practice are advised of the need for a total of 3 months of activity restriction.

• 3. The presence of a compression fracture in the absence of significant axial trauma should raise suspicion. Multiple compression fractures can be a sign of underlying osteopenia, infection, or neoplasm (Fig. 6a–c). Additional imaging modalities and laboratory studies are often required in these cases.

10 Cross-References

• Spinal Cord Injury Without Radiographic Abnormalities (SCIWORA)