High-speed Motor Vehicle Accident: 24-Year-old

History

The patient is a 24-year-old woman, who was a rear passenger in a high-speed motor vehicle accident. She was properly restrained wearing a seat belt. The patient presents with focal thoracolumbar pain.

Examination

The patient is neurologically intact and only complained of severe abdominal pain.

Prior Treatment

The patient had no prior history of spinal complaints.

Images

Anterior posterior (Figure 1, enlarged in Figure 2) and lateral (Figure 3) plain radiographs demonstrate a flexion-distraction injury of T12-L1. Lateral MRI (Figure 4).

Figure 1. Anterior posterior radiograph

Figure 2. Enlargement of Figure 1

Figure 3. Lateral radiograph

Figure 4. Sagittal MRI

Diagnosis

T12-L1 flexion-distraction injury with L1 pedicle fracture and T12-L1 facet disclocation.

Selected Treatment

A closed reduction and percutaneous reduction and stabilization procedure was performed. Fluoroscopy was used in the placement of percutanous pedicular fixation followed by rod placement and reduction of the fracture deformity. (Figures 5-8)

Figure 5. Intraoperative fluoroscopic imaging

Figure 6. Rod passage device

Figure 7. Cephalo caudal passage

Figure 8. Confirming rod passage by turning holder

Post-treatment images
The postoperative lateral plain film below (Figure 9) reveals excellent reduction and stabilization of the flexion distraction injury.

Figure 9. Posteroperative lateral radiograph

Figure 10. Postoperative wounds

Outcome

The patient's postoperative course was uneventful and she was immobilized in a brace for 3 months. At 6 months follow-up, she has minimal pain and is actively participating in a physical therapy strengthening program.

Case Discussion

The patient has a T12-L1 flexion distraction injury with a fracture through the L1 pedicle on the left and superior vertebral body exiting posteriorly through the T12-L1 posterior ligamentous complex. This is further accompanied by a T12-L1 facet dislocation with complete disruption of the black stripe on MRI.

I would obtain a CT scan to further define the bony anatomy, especially looking for facet morphology and posterior fractures. The patient clearly has instability and needs stabilization.

A hyperextension body cast is a reasonable treatment option, although today in 2008, that may be unacceptable to many a patient. Also given the ligamentous injury posteriorly, this may not heal with conservative care and chronic instability may result.

I would operate electively within 24- to 48-hours. The patient should be positioned to maximize lordosis and obtain postural reduction on table, which many a time is easily attainable. My preference would be a Jackson table with extra padding under the thigh and chest to maximize the lordosis.

Posterior stabilization could be achieved with a pedicle screw construct one up (T12) and one down (L2) with posterior fusion (T12 to L2) augmented with rhBMP-2 and local bone. There is no anterior column deficiency and hence a short segment construct seems very viable. There is no indication for a decompression here. The pedicle screws need to be optimized for maximum purchase by placing them parallel to the endplate in the sagittal plane and maximally toed in and convergent in the coronal plane. I would also place them as long as possible. I think that fusion is indicated here given the extensive ligamentous injury posteriorly.

My personal preference would be to treat this patient in a minimally invasive manner with percutaneous screws placed one up (T12) and one down (L2), provided that good postural reduction has been obtained. A system, allowing for free hand percutaneous placement of the rod and for locking the construct together with compression, was used. Once this is done, I would perform a selective fusion of T12-L1 facets through a paramedian incision bilaterally localized to the pedicle of L1. I would similarly augment the fusion with rhBMP-2 and local bone. If rhBMP-2 is not available, I would harvest autogenous cancellous bone from the iliac crest.

Our protocol today is to CT scan these patients at 1-year to ascertain fusion and recommend removal of the instrumentation at 1-year.