Clinical and radiological evaluation of thoracolumbar burst fractures managed with decompression, posterior stabilisation with and without vertebral body reconstruction

Introduction: The thoracolumbar region is most commonly affected by various injury mechanisms. The junction area has a propensity for injury as the mobile lumbar and comparatively less mobile thoracic region meet each other, and there is a long liver arm. The worldwide annual incidence of TL fractures is about 30 in 100,000 inhabitants including osteoporotic fractures. There is a trend to increase the fractures in the elderly population, especially in developed countries, while an increase in motor vehicle accidents in developing countries. The mortality rate among male elderly patients is relatively high. The injury causes loss of vertebral body and subsequent kyphosis which can cause neurological compromise in the lower limbs with loss of bowel and bladder function. Effective decompression of neural structures, restoration of vertebral body height, and rigid fixation and stabilization are needed. The anterior approach for the reconstruction of the vertebral body involves opening the thoracic or abdominal cavity or both for the procedure. The posterior approach alone for the same procedure avoids all those complications, and morbidity.

The rationale of the study supported by cited literature:

Vertebral body reconstruction from the anterior surgical approach needs thoracotomy or laparotomy or both. Anterior approaches have disadvantages as compromise in pulmonary function, and injury to great vessels and vital body organs. The reconstruction of the vertebral body from the posterior approach alone avoids all those complications, and at the same time, it supports the fractured vertebral body with metallic support. If the reconstruction is not done with any approach, there is a report of loss of posterior fixation and or kyphosis in around 40 percent of cases.  In the present study, a cohort of a thoracolumbar burst fracture patients will be treated with the technique of decompression and fixation and the other cohort will be treated with decompression and fixation along with reconstruction of the shattered vertebral body using a cage. The comparison of functional outcomes with radiological parameters will be done at after one year of the operative management.

   Hypothesis:

1.     “Decompression, vertebral body reconstruction and posterior stabilization” (technique B) allow better anterior decompression of the neural tissue, in comparison to the “decompression and posterior stabilization only (technique B)” using the posterior approach alone in the thoracolumbar burst fractures (T10-L2).

2.     Since the new technique (technique B) allows reconstruction of the shattered vertebral body using the same approach in a single operative setting, it may have better long-term restoration of sagittal spine alignment, better function back score, and improved neurological recovery.

  Research questions:

Do decompression and posterior stabilization with vertebral body reconstruction have improved functional and radiological outcome in comparison to decompression and posterior stabilization only using the posterior surgical approach alone in the thoracolumbar burst fractures (T10-L2)?

Aims:

Comparison of functional and radiological outcomes in patients with thoracolumbar burst fractures treated with decompression and posterior stabilization with and without vertebral body reconstruction using the posterior approach alone.

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Objectives:

1.     To evaluate the efficacy of decompression and posterior stabilisation with or without vertebral body reconstruction in the thoracolumbar burst fractures using the posterior approach alone.

2.     To evaluate the efficacy of decompression and posterior stabilization with or without vertebral body reconstruction in patients with thoracolumbar burst fractures in terms of neurological recovery.

     Detailed methodology:

All the patients with thoracolumbar burst fractures with or without neurological compromise will be evaluated successively with their presentation in the department of emergency and in the OPD premises of Orthopaedics AIIMS, Bathinda. On presentation of any patient with a spine injury, they will be offered primary treatment on the lines of ATLS protocol with primary stabilisation. A spine board will be utilized for the initial immobilization of the patients to prevent further injury to the spine.

Upon vital stabilization, all the patients will undergo evaluation for imaging such as radiographs of the part concerned and a non-contrast CT scan of the injured spine. Neurological examination of the extremities will be done using the American Spine Injury Association Impairment Scale ASIA Scale).

Based on the radiographs, the vertebral injury will be classified as per the AO classification of the thoracolumbar fractures. The grading of injury to the vertebral body will be done using the Mc Cormack Score.

 Patient inclusion criteria:

1.     Thoracolumbar burst fractures (T10 to L2) with acute trauma of less than 10 days old in the age group of 20 to 55.

2.     AO, ASIF Type A3, A4

3.     Mc Cormack Score 6 or higher

4.     Sagittal kyphosis 200 or more

Exclusion criteria:

1.     Osteoporotic fractures, patients older than 55 (the existing osteoporosis may bias the result)

2.     Pyogenic or tubercular spondylodiscitis

3.     Patients are not willing to participate in the study.

4.     Medically unfit for the surgical intervention.

Once included in the study, the patients with or without neurological deficit will be planned for the surgical stabilization (posterior only approach) with a due fitness clearance from the anaesthesia department.

Written and informed consent will be taken for all cases for the surgical procedure (utilization of posterior only approach for the stabilization of anterior and posterior column of the spine). The patient will also be informed and written due consent will be taken for their inclusion in the study. Patients will be assured that the fact that findings of the study will not affect their treatment protocol. Epidemiological and demographic factors will be documented.

 Preoperative assessment of all the patients:

1.     Demographic parameters: Age, sex

2.     Mode of injury

3.     Neurological examination of with ASIA scoring system:

4.     AO classification of the thoracolumbar fractures.

5.     TLICS score

6.     Load sharing classification of Mc Cormack

7.     Pre-operative kyphosis at the injured area (Cobb’s method)

8.     Percentage of the canal compromised of the injured spine: an average of the adjacent normal spinal canal will be taken in axial non-contrast MRI for reference purposes.

9.     VAS score for back

10.ODI score

11.Low back outcome score

  Operative intervention:

All the patients of thoracolumbar burst fractures satisfying our inclusion criteria will undergo for the operative posterior stabilization of the injury with instrumentation. The patients will be operated using two different techniques.

Group 1 will be treated with surgical technique A (decompression and posterior stabilization) and group 2 with technique B (decompression and posterior stabilization with vertebral body reconstruction) using a single posterior approach only. The method of allocation of type of treatment to each group will be alternate allocation.

 Intra-operative assessment:

1.     Surgery duration,

2.     Blood loss

3.     Incidence of dural tear

  Follow up- All the patients included in the study will be followed for the minimum one year after their surgery and various functional and radiological outcomes will be assessed.

Comparison:

Both groups will be compared to various functional and radiological parameters in the follow-up.

Outcome measures:

Various functional scores for the back and radiological parameters of the spine will be assessed and compared.

Post-operative assessment and documentation:

1.     VAS for back at 6, and 12 months.

2.     ODI at 6 and 12 months.

3.     Low back outcome score at 6, and 12 months.

4.     Local kyphosis angle at 12 months.

5.     Bony fusion status at 12 months

6.     Events: loss of fixation, implant breakage, exaggeration of kyphosis, infection, etc. Or any other

7.     ASIA Score for neurological assessment at 12 months

   Data analysis plan: Data will be evaluated with various parametric and nonparametric statistical test.

Review of literature:

Thoracolumbar fractures are common injuries. Without appropriate treatment, their outcome can be devastating. Commonly, treatment decision is based upon accurate radiological diagnosis and concomitant use of a fracture classification system. (1)

The injury involves the junctional area of the spine where the rigid thoracic and mobile lumbar spine meet. This is the most common region of the injury in the spine. Out of all the fracture types thoracolumbar injury is the most common. A common mode of injury is a fall from a height and road traffic accidents with high energy of the injury. The injury involves the breakdown of the vertebral body with retropulsion of the bony fragments into the spinal canal, which is, in many occasions, is the chief culprit for the neurological compromise. The neurological deficit could vary from partial to complete cord injury. The bowel and bladder function could be affected to varying severity. (2)

The usual principles of the management of thoracolumbar fractures are immobilization of the spine from the prehospital setting till spine stabilization to prevent further injury to the neural tissue. Surgical stabilization of the unstable thoracolumbar spine is required for neural decompression, correction post post-traumatic kyphosis, and stabilization of the spine. The choices of the surgical approach for fixation of the injury vary from anterior procedure to posterior or both in a single setting or a staged procedure. (3)

Anterior surgery requires a thoracotomy or retroperitoneal anterior spine approach to deal with the fracture. The anterior approach has its own disadvantages like injury to the great vessels, excessive bleeding, long surgery time, and approach-related morbidity. Posterior only approach with vertebral body reconstruction entails. (4)

References:

1.     Curfs I et al. Reliability and Clinical Usefulness of Current Classifications in Traumatic Thoracolumbar Fractures: A Systematic Review of the Literature. Int J Spine Surg. 2020 Dec;14(6):956-969.

2.     Rajasekaran S, Kanna RM, Shetty AP. Management of thoracolumbar spine trauma: An overview. Indian J Orthop. 2015 Jan-Feb;49(1):72-82. Doi: 10.4103 0019-5413.143914. PMID: 25593358; PMCID: PMC4292328.

3.     Roblesgil-Medrano A et al.Thoracolumbar Burst Fractures: A Systematic Review and Meta-Analysis on the Anterior and Posterior Approaches. Spine Surg Relat Res. 2021 Oct 11;6(2):99-108.

4.     Wilcox et. Al. A Dynamic Study of Thoracolumbar Burst Fractures.The Journal of Bone & Joint Surgery 85(11): p 2184-2189, November 2003.