Thoracolumbar burst fracture with horizontal fracture of the posterior column

Posterior tension band wiring and instrumentation for thoracolumbar flexion-distraction injuries

PURPOSE

To evaluate treatment outcome of tension band wiring followed by posterior spinal fusion and instrumentation for thoracolumbar flexiondistraction injury (FDI).

METHODS

36 men and 12 women aged 21 to 56 (mean, 36) years underwent tension band wiring followed by posterior spinal fusion and instrumentation using pedicular screws for FDI of the thoracolumbar spine. The injured vertebral levels were T11 (n=2), T12 (n=12), T11-T12 (n=1), T12-L1 (n=1), L1 (n=28), and L2 (n=4). Anterior vertebral body height and kyphosis were measured before and after surgery. Neurologic status was assessed using the American Spinal Injury Association (ASIA) scale. The Oswestry Disability Index questionnaire and visual analogue scale for pain were also used.

RESULTS

The mean follow-up was 38 (range, 26-72) months. At final follow-up, the mean visual analogue scale for pain was 1.7, and the median Oswestry Disability Index was 4% (range, 0-32%). The mean anterior vertebral body height improved from 20.5 to 38.8 mm (p<0.001). The mean kyphosis improved from 20.4º to 1.5º (p<0.001). Four patients had persistent neurologic deficit: ASIA scale C (n=2) and D (n=2); their ASIA scales improved by one grade. All patients returned to their original work at 6 months. There were no intra-operative complications or implant failures.

CONCLUSION

Posterior tension band wiring followed by posterior spinal fusion and instrumentation for thoracolumbar FDIs achieved good outcome.

Investigation of thoracolumbar T12–L1 burst fracture mechanism using finite element method

A finite element model of the T12-L1 motion segment was subjected to dynamic vertical impact to investigate vertebral burst fracture mechanism at the thoracolumbar junction. A rigid ball was directed vertically towards a rigid plate fixed on top of the T12 vertebral body to simulate the axial impact. The results show that upon impact, the T12 vertebra exhibited a vibratory motion. At its maximum compression, the endplates bulged towards their vertebral bodies. The central parts of the endplates adjacent to the nucleus experienced the highest effective stress, and localized stress concentration developed correspondingly within the central parts of the cancellous bone adjacent to the endplates. This appears to confirm the hypothesis that nucleus material is forced to enter the vertebral body, pressurizing it further and squeezing the fat and marrow contents out of the cancellous bone. When the nucleus material enters the vertebral body faster than fat and marrow being expulsed, the vertebral body could burst through the anterior and posterior cortical shell. Upon sudden posterior cortex fracture, the transient fragment encroachment could be further into the spinal canal than the final observed locations, as the fragments are retropulsed to the vertebral body during the bursting process.

Surgical outcome of thoracolumbar burst fractures with flexion-distraction injury of the posterior elements

Between 1991 and 2002 we treated 48 patients surgically for thoracolumbar burst fractures associated with flexion-distraction injury of the posterior elements. The degree of kyphotic deformity and the degree of vertebral wedging deformity were measured on plain lateral radiographs. The spinal canal compromise was measured on computer tomography. The mean postoperative follow-up was 70 (24-108) months. The preoperative kyphosis averaged 25.7 degrees and the mean sagittal index was 28.8 degrees . The mean wedging deformity of the fractured vertebral body was 46% (24-66%). The mean preoperative spinal canal compromise secondary to retropulsed bony fragments was 64%. Immediately after surgery, the correction of kyphosis averaged 98%. There was no loss of correction at the final follow-up. A satisfactory reduction and good stabilisation with solid fusion were achieved in all cases.

Treatment of spinal fractures in children and adolescents: long-term results in 44 patients

STUDY DESIGN

The authors examined a case series of patients younger than 16 years who had sustained a traumatic spine injury.

OBJECTIVES

To evaluate clinical and radiologic findings and the effectiveness of conservative versus surgical treatment at long-term follow-up.

SUMMARY OF BACKGROUND DATA

Although injuries to children have received increasing coverage in the literature over the last several years, few reports have focused on the long-term results of conservative versus surgical treatment.

METHODS

Forty-four patients who had sustained a traumatic spine injury at the average age of 14 years (range 3-16 years) were clinically and radiographically reviewed. The fractures were separated into three groups: stable (n = 20) and unstable (n = 13) injuries without cord lesion and fractures with spinal cord lesion (n = 11). Mean follow-up was 18 years (range 9-23 years).

RESULTS

Conservative treatment was successful in all stable fractures, whereas it failed in the unstable injuries. The surgical treatment stabilized without significant deformity in five of the seven unstable fractures. Of 11 with spinal cord injuries, the 4 children conservatively treated developed a severely progressive, paralytic scoliosis. Only three of the seven surgically treated patients were stabilized without any deformity at follow-up.

CONCLUSION

In children and adolescents, conservative treatment is an available option for stable fractures without neurologic lesion. Early surgical treatment (instrumentation and fusion) is mandatory for unstable fractures and injuries associated with spinal cord lesion. In children, a traumatic spinal cord lesion may develop a deformity that is mainly scoliotic, kyphotic, or lordotic in >90% of the cases.

Classifications of thoracic and lumbar fractures: rationale and supporting data

Classification systems are generalizations that attempt to identify common attributes within a group to predict behavior or outcome without sacrificing too much detail. Because of the inherent variability of fractures, classifying them can be difficult. To properly apply any of the commonly cited classification schemes for thoracic and lumbar fractures, one must not only know the injury categories described in the original studies but also be familiar with the rationale for developing the classification. Many original reports describing common thoracic and lumbar injury classifications lack a rigorous scientific foundation. They were based largely on the insights of experienced surgeons and researchers. Although the ideal classification for thoracic and lumbar fractures does not exist, it would incorporate neurologic as well as structural factors. Standardization of terminology as related to treatment decisions and prognosis is key to an improved understanding of the clinical behavior of these injuries and identification of optimal treatment options.