Outcome of Treatment of Traumatic Thoracolumbar Spine Fractures

        Outcome of Treatment of Traumatic Thoracolumbar Spine Fractures

 

                                                       Dr. KS Dhillon

Introduction

Fractures of the thoracolumbar spine are relatively common and represent about 65% of all traumatic spinal fractures. Thoracolumbar fractures are more common in men, and the peak incidence is seen between the ages of 20 and 40 years.

Fifty percent of thoracolumbar fractures are unstable fractures. These injuries can produce permanent disability resulting in significant social and economic burden on society. Neurological injury can be present in about 20% to 36% of the patients with thoracolumbar fractures. Neurological deficit can result in severe physical disability. It is usually not possible to predict neurological recovery in patients with traumatic spinal cord injuries because recovery depends on several preoperative prognostic factors.

The outcome of treatment of thoracolumbar fractures without neurological deficit is generally good on long term follow up. Despite technological advances in the treatment of spinal fractures, outcomes of surgery, however, remains unpredictable.

Classification of thoracolumbar fractures

There are several classification systems for thoracolumbar fractures of which the most commonly used one is that by Denis.The Denis classification divides the spine into three columns, the anterior, middle and posterior column. The anterior column consists of the two anterior third of the vertebral body and discs and the anterior longitudinal ligament, the middle column consist of the posterior third of the vertebral body and disc as well as the posterior vertebral body wall and the posterior longitudinal ligament and the posterior column consists of the pedicles, laminae, facet joints and the posterior ligamentous complex (PCL) [1]. This classification is only moderately reliable in determining clinical degree of stability. Instability is said to be present if two or more columns are disrupted.

The Denis classification has been criticized for being too simplistic that it fails to identify ligamentous injuries which can lead to occult, progressive instability.

The Spine Trauma Study Group have introduced a new classification system called the thoracolumbar injury classification and severity score (TLICS). This classification system is based on injury morphology, posterior ligamentous complex integrity and the neurologic status of the patient [2].
The injury morphology can be identified from the imaging studies. There are 3 types of injuries, compression injuries (which can produce a compression fracture or a burst fracture), translational/rotational injuries, and lastly the distraction injuries. The compression fracture is allotted 1 point, a burst fracture 2 points, translational and rotational injuries 3 points and distraction injuries 4 points (table 1).

TLICS scoring

Parameter                                              Points
Morphology
Compression fracture                                1           
Burst fracture                                            2
Translational/rotational                             3
Distraction                                                 4

Neurologic involvement
Intact                                                         0
Nerve root                                                 2
Cord, conus medullaris
Incomplete                                                3
Complete                                                  2
Cauda equina                                           3

Posterior ligamentous complex
Intact                                                         0
Injury suspected/indeterminate                  2
Injured                                                        3

Table 1. TLICS scoring system [2]

There are five categories of neurologic injury, namely intact neurologic status, nerve root injury, complete spinal cord injury, incomplete spinal cord injury, and cauda equina syndrome. Patients with intact neurologic status are alloted zero points, nerve root injury or complete spinal cord injury are allotted two points and patients with an incomplete spinal cord injury or cauda equina syndrome are allotted three points. In the last group higher points are allotted because surgical decompression in these patients can be very useful.

For the posterior ligamentous complex there are 3 categories. The first where the PCL is intact (0 points), second where injury is suspected (2 points and the third where the PCL is disrupted (3 points). A palpable interspinous gap and interspinous widening on x rays would be present when the PCL is completely disrupted.

The allotted points in the three categories are added up to get the total score which will help in decision making as to whether or not surgery should be carried out to treat the injury. Patients with 3 or less points are treated nonoperatively and patients with 5 points or more are treated operatively. Patients with a total score of 4 belong to an indistinct group, where either nonoperative or operative treatment can be considered (Table 2).

Management as per TLICS score

Management                            Points
Nonoperative                             0–3
Nonoperative or operative           4
Operative                                    ≥5

Table 2. Management as per TLICS score [2]

Outcome of treatment of thoracolumbar fractures

Abudou et al [3] carried out a Cochrane systematic review of literature upto September 2012 to compare the outcomes of surgical with non-surgical treatment of patients with thoracolumbar burst fractures who had no neurological deficit. They were only able to find two suitable studies which reported the outcome in 79 patients who were followed up for two years or more. Both studies were judged to have unclear risk of selection bias and a high risk of performance and detection biases because of lack of blinding.

They found that there is insufficient evidence in literature  to conclude ‘whether surgical or non-surgical treatment yields superior pain and functional outcomes for people with thoracolumbar burst fractures without neurological deficit’ [3]. Surgery can be associated with early complications and need for repeat surgery. Surgical treatment is more costly than  non-surgical treatment.

Gnanenthiran et al [4] carried out a meta-analysis to compare pain (VAS) and function (Roland Morris Disability Questionnaire) in patients who had thoracolumbar burst fracture with no neurologic deficit and were treated surgically or non-surgically. Secondary outcomes measured included ‘return to work, radiographic progression of kyphosis, radiographic progression of spinal canal stenosis, complications, cost, and length of hospitalization’[4]. They found that there was no differences in pain, RMDQ score, kyphosis, and return to work rates between the two groups. There was better radiographic correction in the surgical group but surgical treatment was associated with higher complication rate and higher cost of treatment.

The authors concluded that there was insufficient evidence in literature to support the superiority of surgical treatment over non-surgical treatment in the treatment of patients with thoracolumbar burst fractures with no neurologic deficit.

Bakhsheshian et al [5] did a systematic review of literature over a 20 years period to assess the outcome of nonoperative management of traumatic thoracolumbar burst fractures. There wear 45 studies which met their inclusion criteria. Of these 45 studies,16 studies investigated techniques of conservative treatment, 20 studies compared surgical to non-surgical management, and 9 papers investigated the prognosis of non-surgical treatment.

They found 9 high-level studies (Levels I–II) which investigated the non-surgical management of burst thoracolumbar fractures.They found that the outcome of treatment in neurologically intact patients was the same irrespective of the technique used for conservative treatment. No one technique was found to be superior to another.

There was a high level of evidence which demonstrated that the functional outcomes with non-surgical management when compared with surgical management was the same in patients who had no neurological deficit. There was high level evidence to show that neurological deficit is not an absolute contraindication for conservative treatment.

Scheer et al [6] carried out a systematic review of literature, including publications over a 20 years period, to assess the outcome of surgical treatment of thoracolumbar burst fractures. Twenty three level 1 and level 2 studies met their inclusion criteria.

They found that there was high level evidence for short or long-segment posterior pedicle instrumentation of the spine without fusion. Long-segment pedicle fIxation provided better correction as compared to short segment fixation.  The Low Back Outcome Scores (LBOS) however were similar. Long constructs provided more rigidity but it reduced patient mobility which affected patients quality of life.

Spinal fusion is not necessary in addition to spinal instrumentation. Fusion does not improve clinical or radiological outcome after posterior instrumentation. Fusion can, however, increase the operative time and risk of infection. Open approaches to spine surgery can be associated with higher morbidity. High level evidence shows that the thoracolumbar muscle attachments are best preserved and percutaneous as well as paraspinal approaches are useful for the treatment of thoracolumbar burst fractures.
There is level 2 evidence to show that the radiographic, clinical, and functional outcomes are similar irrespective of whether an anterior, posterior, or combined approach is used for instrumentation. The complication rates are higher with the anterior and combined approaches  as compared to the posterior approach. The cost of treatment was higher with the anterior approach as compared to the posterior approach.

Moller et al [7] studied the outcome of nonoperatively treated burst fractures of the thoracic and lumbar spine in adults at an average follow up of 27 years (range 23 to 41 years). Their study included 16 men with an average age of 31 years and 11 women with an average age of 40 years.
There were 4 Denis type A burst fractures, 18 Denis type B, 1 Denis type C, and 4 Denis type E fractures. Seven patients had neurological deficits.

At follow-up, 21 patients reported no or minimal back pain or disability with an Oswestry mean score of 4 (range 0-16). Six patients, three of who were classified Frankel D at baseline reported moderate or severe disability with an Oswestry mean score of 39 (range, 26-54). Of the 27 patients, 6 were classified as Frankel D, and 21 were classified as Frankel E. They found that the local kyphosis had increased by a mean of 3 degrees. The disc height adjacent to the fractured vertebra remained unchanged at follow up.

They concluded that the long term outcome, of nonoperative treatment of  burst fractures of the thoracolumbar spine in adults with minor or no neurological deficit, is predominantly favorable and that there appears to be no increase in risk for disc height reduction in the adjacent discs on long term follow up.

Moller et al [8] studied the long term outcome of treatment of thoracolumbar vertebral fractures in late adolescence. Eighteen boys and 5 girls with thoracolumbar fractures were followed up after 27 to 47 years with  subjective, objective and radiological evaluation. Fourteen patients had a one-column compression fracture, one had a Denis type A, six a Denis type B, one a Denis type D and one patient had a Chance fracture. At baseline  one had a partial paresis of one leg and another one developed a transient paraparesis during the first week. All the patients were treated non-surgically. At the last follow-up, 18 patients had no complaints, 5 had occasional back pain. Twenty were classified as Frankel E and 3 were classified as Frankel D. The radiographic vertebral height of the fractured vertebra remained unchanged during the study period.

They concluded that patients in late adolescence who are treated conservatively for thoracolumbar fractures with minor or no neurological deficit have a favourable long-term outcome.

The post traumatic kyphosis in the fractured region following thoracolumbar fractures in children below 13 years at the time of injury can decrease with time. Karlsson et al [9] did a study involving 12 boys and 12 girls, aged 7-16 years who sustained thoracolumbar fractures which were treated conservatively. The follow up period was between 27 to 47 years.  They found that in 8 individuals (33%), all aged 13 or less at the time of the fracture, there was a decrease of post traumatic kyphosis at the last follow up. This would mean that remodelling of the vertebrae is possible in young children. No increase in degeneration of the adjacent disc was observed in this study.

Outcome of treatment in patients with neurological deficit

Literature on the long term outcome of treatment of patients with thoracolumbar fractures associated with neurological deficit is sparse.

Dobran et al [10] carried out a retrospective analysis of 69 patients who were treated operatively for traumatic spinal cord injury. The patients had posterior stabilization of the spine performed within 24 hours of the the trauma. Surgery was indicated in patients with neurological deficit, severe spinal deformity with canal encroachment of more than 50%, vertebral body wedging of more than 60%, kyphosis of more than 25° and when there was spinal instability.

At one year follow up, 72.4% of the patients with neurological deficit show an improvement in neurological function and no patients deteriorated after the surgery.

The neurological improvement rates were 88.46% in patients with lumbar injuries, 45.45% in thoracic injuries and 66.6% in patients with thoracolumbar injuries.

In patients with thoracolumbar spinal cord injuries, 72.4% of the patients neurologically improved one or more ASIA (American Spinal Injury Association) level after the surgery compared to the neurological status on admission.

Marré et al [11] carried out a retrospective review of 51 patients who had thoracic fractures and were treated by surgery. Of the 51 patients who had surgery, 6 had incomplete neurological deficit and 22 had a complete lesion on admission.

Three of the four patients who were ASIA B at presentation improved one ASIA grade at one year follow up. Two patients with ASIA D made full recovery. Five of the 6 patients (83.3%) who had an incomplete cord injury demonstrated neurological recovery during their follow-up.

The study showed that in none of the patients with ASIA A there was improvement in their neurological status. There was no deterioration of neurological status in any of the patients.
Verlaan et al [12] carried out a systematic review of the literature, to evaluate surgical treatment of traumatic thoracic and lumbar spine fractures. They found a 132 full-text papers from 1970 until 2001. The majority of the papers were retrospective case-series. The total number of patients in these papers was 5,748 patients. There were five surgical techniques that were used for treatment of these patients. This included  posterior short-segment, posterior long-segment, anterior and combined anterior with posterior (AP) techniques.

They assessed the neurological, radiologic, and functional outcome and complications in this group of patients. They found that partial neurological deficits had a potential to resolve irrespective of the type of surgical treatment provided. Surprisingly, none of the five techniques used was able to maintain the corrected kyphosis angle. The functional outcome after surgery appears to be better than what is usually assumed by most people. They found that complications after surgery were uncommon.

Conclusion

Treatment of traumatic thoracolumbar burst fractures remains a challenge. There appears to be no consensus as to what is the best techniques for operative and nonoperative treatment of these fractures. The main aim of treatment is to mobilize the patient early and to obtain a stable spine with maximum mobility  as well as to obtain the best possible neurological outcome. In patients who have no neurological deficit the optimal treatment is nonsurgical. There is high level of evidence to show that the outcome of conservative treatment in patients with no neurology is the same as those with surgical treatment without the complications associated with surgery. The cost of nonsurgical treatment is also lower then surgical treatment.

The evidence in support of the optimal treatment for patients with neurological deficit, however, remains unclear. When clinical and radiological assessment shows that the patient requires surgery, there is no consensus on the technique to be used for spinal stabilization. There, however, is some evidence in literature to show that short- or long-segment pedicle instrumentation without fusion is preferable. The percutaneous and paraspinal approaches have been found to be less invasive.
The long term outcome of conservative treatment of burst fractures of the thoracolumbar spine in adolescents and adult with no or minor neurological deficit is generally favourable.

There are several surgical techniques available for the treatment of unstable spine fractures. Studies show that there is no one technique which is superior to another. The anterior and combined approaches were associated with more complications. Partial neurological deficits after spinal injuries have a potential to resolve but ASIA A type of complete paralysis usually has no potential for recovery.

References

1. Denis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine. 1983;8:817–831. 
2. Vaccaro AR, Zeiller SC, Hulbert RJ, Anderson PA, Harris M, Hedlund R, et al. The thoracolumbar injury severity score: a proposed treatment algorithm. J Spinal Disord Tech. 2005;18:209–15.
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8. Moller A, Hasserius R, Besjakov J, Ohlin A, and Karlsson M. Vertebral fractures in late adolescence: a 27 to 47-year follow-up. Eur Spine J. 2006 Aug; 15(8): 1247–1254.
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10. Dobran M, Iacoangeli M, Di Somma LG M, Rienzo AD, Colasanti R, Niccolò Nocchi, Alvaro L, Moriconi E, Nasi D, Scerrati M. Neurological outcome in a series of 58 patients operated for traumatic thoracolumbar spinal cord injuries. Surg Neurol Int 28-Aug-2014;5.
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