Keywords
outcome - burst thoracolumbar fractures
Palavras Chave
resultado - fraturas toracolombares do tipo explosão
Introduction
Thoracolumbar fracture is the most common type of spine fracture.[1]
[2] Falling and motor vehicle accidents are among the most common causes of thoracolumbar injuries.[3] Burst fracture of the spine is a serious injury that commonly occurs among young people. Thoracolumbar burst fracture is defined as a fracture in the anterior and middle column of the spine, secondary to an axial pressure.[4] Patients are prone to serious disorders, which can be life threatening, as well as to postoperative problems, such as pressure sores, deep venous thrombosis, and pulmonary infections.[2]
[5]
[6]
An unstable burst fracture of the thoracolumbar spine is an indication for instrumentation. Unstable fractures are burst fractures that involve the posterior column of the vertebrae and the tearing of the posterior longitudinal ligament.[7] Short and long segment instrumentation are two different choices for internal fixation.[4] The short segment instrumentation is the fixation of bilateral pedicle screws one normal level above and one normal vertebra below the injured segment. In contrast, long segment instrumentation is the fixation of two segments above and two segments below the fractured vertebrae.[8] Surgeons desire to minimize the number of vertebral levels that are involved in the instrumentation process.[9] The development of transpedicular screw instrumentation techniques and of instrumentation systems has brought short segment instrumentation into the general clinical practice.[10] However, the optimal management of thoracolumbar fractures is controversial.[11]
The short segment posterior instrumentation can reduce the bleeding and preserve segmental motion with an acceptable anatomic and functional outcome.[4] Short-term follow-up results have suggested a favorable outcome in short segment instrumentation.[12]
[13]
[14]
[15] Although there are reports of high percentages in instrumentation failure, verifying its longer-term evaluation is required.[16]
[17]
Therefore, we have aimed to evaluate the outcome of six-screw instrumentation (short segment) in the treatment of burst fractures, measuring postoperative pain and neurologic deficits after 12 months of surgery.
Methods
Study Population
From December 2014 to July 2016, 19 new thoracolumbar (T11 to L3) burst fracture patients (15 males and 4 females) with an average age of 30.7 years old (range: 18–59 years old) were operated on with the short segment transpedicular fixation method by a neurosurgeon in the Fasa Valiasr Hospital. This hospital is a general hospital located in the Fars province, Iran.
All of the patients underwent plain X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) exams. On arrival, the patients underwent a full neurologic examination, which was assessed with the Frankel classification by the neurosurgeon. Then, the patients were followed-up after 12 months. The inclusion criteria were (a) a single level fracture between the T11 and the L3; (b) only short segment instrumentation (one-above, one-below, and the fractured vertebra); (c) a local kyphotic angle > 30 degrees, or an anterior height collapse > 50%, or spinal canal involvement > 50%. A written informed consent was obtained from each patient.
Surgical Technique
The patients were placed in the prone position under general anesthesia. Before the incision, the fracture level was determined under C-Arm control. A midline linear thoracolumbar incision was routinely done from one vertebral body above the fractured site to one vertebral body below it. After cutting the fascia and stripping the prevertebral muscles, a subperiosteal dissection was performed to decrease bleeding. According to the CT and MRI exams of the patients, a laminectomy was performed in the patients who had a neurologic deficit secondary to cord compression or canal compromise > 50%. After the procedure, a physical exam was performed, and anteroposterior and lateral X-rays were taken.
Postoperative Care and Follow-up Evaluation
All of the patients were encouraged to walk after 24 to 48 hours postoperatively, and the brace was applied for between 4 and 6 weeks. The medical records of every patient, including age, gender, injury level, fracture type, the cause of injury, underlying diseases, operative time, blood loss, the extent of the fixation, and perioperative complications, were collected. A visual analog scale (VAS) was assigned to evaluate back pain.[18] The Oswestry disability index (ODI) was used to evaluate the postoperative function.[19] The final clinical results were assessed using the Denis scale, which is a 5-point scale that includes both work and pain scales.[20]
Statistical Analysis
Data were analyzed using software STATA version 12 (StataCorp, College Station, TX, USA).
Results
During the study period, 19 patients with unstable thoracolumbar fractures were operated, using short segment posterior spinal six-screw instrumentation ([Fig. 1]). The study population included 15 men and 4 women, with a mean age of 30.7 years old (range: 18–59 years old). The causes of the thoracolumbar fractures were motor vehicle accidents (11 cases) and falling from heights (8 cases). The most common vertebra involved was the L1 (47.36%), followed by the T12 (26.31%), the L2 (10.52%), the L3 (5.26%), the L4 (5.26%), and the L5 (5.26%). One of the patients had uncontrolled diabetes. None of the patients were affected by hypertensive disease, coagulopathies, or chronic illnesses. One patient was a smoker, and one patient was addicted to heroin. None of the patients complained of any previous trauma before the injury, but three patients had previous back pain. The mean ± standard deviation (SD) surgical time was 70 ± 11 minutes (range 60–90 minutes) and the mean ± SD intraoperative blood loss was 126–27 ml (range: 90–170 ml). The mean hospital stay was 4.6 days. Laminectomy was performed in 9 patients. The reason for laminectomy was the presence of a preoperative neurologic problem, which appeared in two patients (sphincter problem and saddle hypoesthesia in 1 case and motor deficit (Frankle D) in 1 case, which resolved after the operation in both patients. The other 7 patients had a canal compression > 50%.
Fig. 1 Postoperative biplanar radiography.
All of the patients were assessed 12 months after surgery and evaluated for pain at the time of follow-up. The average pain score according to the VAS was 1.63 ± 1.25 ([Fig. 2]). The patients were classified according to the Denis work scale. The patients were predominantly categorized in grade 1 and 2 ([Table1]). The patients were also classified according to the Denis pain scale. There were no grades 4 or 5 ([Table 2]). Also, the mean postoperative ODI was 37% after the one-month follow-up. In the most recent follow-up, the average ODI was minimal, at 17%. A patient had Frankle D and a patient had urinary retention with saddle hypoesthesia. Both of them improved after the operation without any signs of neurologic problems.
Table 1
Distribution of patients classified by the Denis work scale
|
Criteria
|
Grade
|
N%
|
|
Return to previous employment (heavy labor) or physically demanding activities
|
1
|
9 (47.36%)
|
|
Able to return to previous employment (sedentary) or return to heavy labor with lifting restrictions
|
2
|
7 (36.84%)
|
|
Unable to return to previous employment, but working full-time at a new job
|
3
|
3 (15.78%)
|
|
Unable to return to full-time work
|
4
|
0 (0%)
|
|
No work, completely disabled
|
5
|
0 (0%)
|
|
Total
|
|
19 (100.0%)
|
Table 2
Distribution of patients classified by the Denis pain scale
|
Criteria
|
Grade
|
N%
|
|
No pain
|
1
|
12 (63.15%)
|
|
Occasional, minimal pain, no need for medication
|
2
|
6 (31.57%)
|
|
Moderate pain, occasional medication, no interruption of work or activities of daily life
|
3
|
1 (5.26%)
|
|
Moderate to severe pain, occasional absences from work, significant changes in activities of daily life
|
4
|
0 (0%)
|
|
Constant severe pain, chronic medication
|
5
|
0 (0%)
|
|
Total
|
|
19 (100.0%)
|
Fig. 2 Distribution of patients in different pain scores after the operation according to the visual analogue scale.
Discussion
The result of the present study shows that the majority of the patients with thoracolumbar fractures were young people in the functional years of their lives who required treatments that would facilitate their functional state and enable a reduction in complications. Most of the fractures were caused by motor vehicle accidents and involved more men than women, which is in line with Western studies.[21]
[22]
The results of the present study corroborate the reported benefits of pedicle screws in the fractured vertebra and the efficacy of the six-screw construct for the treatment of thoracolumbar burst fractures. Pellisé showed that the six-screw construct, a short-segment instrumentation including the fractured level, is an efficient procedure for the treatment of thoracolumbar burst fractures.[23] It was reported that the prevalence of posterior instrumentation failure ranged from 9 to 54%.[24]
[25] However, no failure was observed in the present study.
Low blood loss and short operation times were also two other favorable achievements. The similarity of our results with previously published surgical data (surgical time and blood loss), surgical correction, and postoperative correction loss suggest that the short-segment six-screw technique is feasible.[23] Uzumcugil et al noted that the average hospital stay was 24 days, which was 4.6 days longer than in our study.[26] Gajjar et al suggested that this difference in the duration of hospital stay might be due to the referral from one center to another from distant places and to the waste of valuable time for the much-required surgery.[5]
In the present study, postoperative pain in the VAS and in the Denis pain scale was low. Most cases did not involve severe pain, suggesting that this surgical method can reduce both resting time and activity-induced pain. The patients showed a satisfactory ability to return to their previous employments (sedentary) or to return to heavy labor with some lifting restrictions, or even physically demanding activities, according to the Denis work scale and to the ODI questionnaires, which shows that this method could also improve the functional outcome, especially in young patients.
However, we suggest further studies with a longer follow-up and a larger sample size to provide a more conclusive result.
Conclusion
The outcome of the studied patients, including operation time, blood loss, transfusion requirement, and postsurgical clinical pain and functional outcome of the patient suggested that the short-segment instrumentation could be an appropriate method for patients with unstable thoracolumbar junction fracture. However, a long-term follow-up is recommended.
