Although it is known that a change in any level of the spine alters biomechanics, there are not many studies to evaluate the spine as a whole in both sagittal and frontal planes. This prospective cohort study evaluates the morphology and mobility of the entire spine in patients with vertebral fractures. The Treatment Group consisted of 43 patients who underwent percutaneous balloon kyphoplasty or percutaneous balloon kyphoplasty plus fixation. The Control Group consisted of 39 healthy subjects. Spinal Mouse was used for the assessment of the curvatures and the mobility of the spine. Clinical outcomes were evaluated by Visual Analogue Scale and Oswestry Disability Index. The measurements were recorded at 15 days and 3, 6, and 12 months postoperatively. Regarding the curvatures and mobility in sagittal plane, a statistically significant increase appeared early at 3 months, for lumbar curve, spinopelvic angulation, and overall trunk inclination. In the frontal plane, most of the improvements were recorded after 6 months. Patients with osteoporotic fracture showed statistically significant lower mean value than patients with traumatic fracture. Pain and disability index showed early improvements. This study provides a comprehensive and complete picture of the functionality of the spine in patients treated with percutaneous balloon kyphoplasty.
It is estimated that every year over 1.4 million people worldwide sustain vertebral fractures (VFs) [
Treatment of VFs includes percutaneous balloon kyphoplasty (BKP) and BKP plus fixation [
For the abovementioned reasons, the purpose of the present study is to provide further evidence for the evaluation of the morphology and functionality of the global spine, in patients with VF, with a new valid, reliable, and noninvasive method both in sagittal and in frontal planes.
From September 2010 to December 2012, 43 patients were treated (Treatment Group, TG) with BKP or BKP plus short minimal invasive fixation, due to osteoporotic or traumatic VF in the thoracic, lumbar, or thoracolumbar spine. All patients were followed up for one year postoperatively. Thirty-nine completed the full evaluation protocol. Two of the patients presented fracture in an inferior level between 6 and 12 months and two abandoned our study for personal reasons. The diagnosis of VF was made by plain radiography, Computed Tomography (CT), and/or Magnetic Resonance Imaging (MRI). All patients’ profiles were assessed regarding the appropriateness for kyphoplasty procedure. Exclusion criteria were previous vertebroplasty or balloon kyphoplasty or other spine surgeries, pedicle fractures, local or systemic infection, preexisting chronic back pain or inability to stand, hemiplegia or stroke, ankylosing spondylitis, spondyloarthropathy, dementia, psychiatric history or other mental inabilities to participate in the study, and age higher than 75 years. All subjects were operated on by the same orthopaedic surgeon at the same center.
Thirty-nine healthy subjects who had no pathology of the spine or the lower limbs comprised the Control Group (CG). All of them had no history of neuromuscular and musculoskeletal pathology or injury.
All participants were informed in detail on the purpose of the study and signed an informed consent form approved by the Bioethics and Scientific Committee of the University Hospital of Heraklion (10787/20-12-10).
Regarding the evaluation of the spine, both groups were assessed with Spinal Mouse (Idiag, Volketswil, Switzerland), a computer-assisted wireless telemetry device, which is guided along the spinous processes of the vertebral column. A computer device receives all the data obtained by the Spinal Mouse in real time and reproduces a two-dimensional graph of the spine (Figure
Spinal Mouse is a device which is guided manually on the skin along the spine. Reconstruction of the spine in neutral and extreme positions in sagittal and frontal plane. The images are derived from real measurements in one patient. Sagittal plane: (a) upright position, (b) full flexion, and (c) full extension. Frontal level: (a) upright position, (b) left lateral bending, and (c) right lateral bending.
Only the subjects of the TG were asked to fill two questionnaires. Back pain was evaluated using the Visual Analogue Scale (VAS: 0 = no pain at all, 10 = worst pain imaginable) [
CG spinal function and mobility were evaluated at the same environment with TG. Subjects in CG were assessed only once.
The same procedure and order were followed for all measurements. This particular measurement technique and the parameters which were counted have been described in the literature [
Paired
One-way ANOVA was used to determine whether there were any significant differences between the means of CG, in comparison with the mean values of TG of the 12-month postoperative reevaluation. It was also used to compare the means of patients that were treated with BKP and those who were treated by using BKP plus short minimal invasive fixation and to compare the means of groups’ patients based on type of fracture (osteoporotic and traumatic).
SPPS 15.0 was used for statistical analysis. All statistical tests were carried at the 5% level of significance.
Demographic and anthropometric characteristics of TG and CG are presented in Table
Demographic and anthropometric characteristics of the participants.
Treatment Group (TG) |
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Gender | ||
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Female |
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Age | 57.15 (±15.97) | 51.82 (±11.74) |
Height | 1.66 (±0.08) | 1.69 (±0.08) |
Weight | 74.26 (±10.67) | 73.03 (±13.18) |
BMI | 26.97 (±3.58) | 25.62 (±3.55) |
The total number of fractures that appeared in each level. L1 showed the greatest possibility for fracture (28.9%).
The statistically significant changes are mainly presented in the reevaluations of 3, 6, and 12 months, in comparison with the measurement in 15 days postoperatively. Improvement in the thoracic curvature appears only during the measurement in the position of full extension. Statistically significant increase for the lumbar curve appears early at 3 months, in comparison with the 15-day evaluation, which in upright position was maintained up to 12 months, while in full flexion and full extension it continues to show a slight increase up to 12 months. It is worth mentioning that, in the upright position, lumbar curve was 17.85° in 15 days, increased to 23.7° in the 3-month evaluation, and remained almost unchanged up to 12 months. Finally, statistically significant improvements are shown in spinopelvic angulation (hip sacral angle, Sac_Hip) and in the overall trunk inclination (Incl).
There were no statistically significant changes in the upright position regarding lumbar and thoracic curvatures. Statistically significant improvements for right and left lateral bending positions for the thoracic curve were observed at the 6-month evaluation, but for the lumbar curve in 12 months compared with the 15-day reevaluation.
The statistically significant changes that were recorded in the sagittal and frontal planes are presented in Table
Spine curvatures measurements for all positions in sagittal and frontal plane.
Spinal curvatures | ||||||
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3 versus 15 | 6 versus 15 | 12 versus 15 | 6 versus 3 | 12 versus 3 | 12 versus 6 | |
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Incl |
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Full extension | ||||||
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Incl |
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Frontal plane | ||||||
Upright position | ||||||
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Left lateral bending | ||||||
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Thoracic curve |
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Lumbar curve |
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Incl |
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Right lateral bending | ||||||
Thoracic curve |
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Lumbar curve |
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Incl |
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Few of the parameters showed statistically significant differences, between the 3- and 6-month measurements. Most of the parameters exhibited improvement already from 3 months. A typical example is the increase of range of motion (ROM) of lumbar curvature from the upright position to full flexion (AF). In 15 days it was
There was no statistically significant change in any parameter in 6 months in comparison with 3-month reevaluation. Most of the improvements were recorded after 6 months. For example, lumbar curvature from the standing position to the full left lateral bending (SL) increased at
All the parameters which showed statistically significant changes between reevaluations are presented in Table
Statistically significant changes in the mobility of the spine in the sagittal and frontal plane among reevaluations.
Spinal mobility | ||||||
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3 versus 15 | 6 versus 15 | 12 versus 15 | 6 versus 3 | 12 versus 3 | 12 versus 6 | |
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Sac_Hip |
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Lumbar curve |
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Incl |
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AE | ||||||
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Thoracic curve |
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Incl |
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FE | ||||||
Sac_Hip |
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Thoracic curve |
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Lumbar curve |
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Frontal plane | ||||||
SL | ||||||
Sac_Hip |
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Thoracic curve |
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Lumbar curve |
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Incl |
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SR | ||||||
Thoracic curve |
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Lumbar curve |
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Trunk Incl |
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LR | ||||||
Sac_Hip |
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Thoracic curve |
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Lumbar curve |
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Incl |
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There were statistically significant improvements between all the reevaluations and significant reduction of the score.
Between all reevaluations a statistically significant decrease was recorded up to 6 months, while the assessment at 12 months did not exhibit any statistically significant change.
The mean values and the statistical significant changes for the questionnaires are presented in Table
Statistically significant improvements from the evaluation of the questionnaires ODI and VAS.
ODI |
VAS-back | |
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Mean value and SD | ||
15 days | 69.36% ± 1.45% | 5.69 ± 0.18 |
3 months | 45.51% ± 1.97% | 3.59 ± 0.17 |
6 months | 17.56% ± 1.65% | 1.62 ± 0.17 |
12 months | 11.64% ± 1.69% | 1.28 ± 0.28 |
Comparison of reevaluations | ||
3 months versus 15 days |
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6 months versus 15 days |
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12 months versus 15 days |
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6 months versus 3 months |
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12 months versus 3 months |
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12 months versus 6 months |
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The main statistically significant changes between the two groups are shown in Table
Statistically significant differences between the CG and TG, based on the measurements of Spinal Mouse (
TG versus CG | ||||
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Sac_Hip | Lumbar curve | Thoracic curve | Incl | |
Sagittal plane | ||||
Upright position |
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Full flexion |
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Full extension |
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AF |
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AE |
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Frontal plane | ||||
Upright position |
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Left bending |
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Right bending |
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SL |
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SR |
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LR |
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Both in the sagittal and in the frontal plane, for all the parameters, no statistically significant differences were recorded.
According to the type of fracture, in the final evaluation, patients with osteoporotic fracture showed statistically significant lower mean value (
It is well accepted that disturbances in the curvatures and functional limitations of the spinal column following a fracture induce significant problems, especially in the elderly [
In our study most of the fractures occurred in T12 and L1 vertebrae. In total, 71.1% of all fractures were located in the thoracolumbar spine (TLS) junction (T11-L2). This is supported by the literature, where it is mentioned that over 60% of VFs occur in the TLS junction [
In a randomized trial, BKP was compared to nonsurgical treatment. Early positive results of BKP, clinically, radiologically, and in QOL, were shown at the first month [
In our study a significant element is the fact that most of the improvements were presented early from the 3-month evaluation and in some parameters those improvements continued up to 12 months. Typical examples are the measurements of Sac_Hip and Incl. It is well known that Sac_Hip angle is directly correlated with spine curvatures and that spine deformity and imbalance in the sagittal plane create compensatory mechanisms on the spinopelvic complex. Also, Sac_Hip angle changes with age, rotating backward [
Regarding the lumbar curve decreased lordosis, which was recorded in the 15-day evaluation, might be due to the presence of paraspinal muscle spasm [
In the present study all the parameters showed improvement mainly after 6 and 12 months suggesting that, in comparison with the sagittal plane, these improvements appear at lower rate.
Generally, even though the positive results of BKP in the curvatures of the spine are shown early many factors tend to improve up to 12 months.
It has been proven that reduced spinal mobility causes significant impairment, especially in the elderly [
Similarly with the results that were recorded for spinal curvatures, mobility improvements in the frontal plane were demonstrated mainly 6 months postoperatively. To the best of our knowledge, there are not any studies which examined the mobility of the spine in the frontal plane. There is no obvious explanation why these improvements, in that particular plane, presented later than in sagittal plane. One hypothesis for this could be that spinal deviations in frontal plane are correlated with alteration of loading which is applied to the facet joints [
Regarding VAS score, it is known that BKP and vertebroplasty offer instant and significant relief from pain and present better results in comparison with conservative treatment [
Also, ODI evaluation showed significant improvement of functionality. The superiority of kyphoplasty over the other methods and the gradual reduction of score throughout the first year has been recorded in the literature [
Although there were very good results during all reevaluations, regarding spinal curves, mobility, pain, and functionality, finally the TG was more inferior than CG, especially in the parameters of lumbar spine. On the other hand, TG showed better mobility in Sac_Hip than CG. These results might have compensatory action as Sac_Hip angle and mobility are correlated directly with lumbar lordosis and mobility [
Finally, in the present study no differences were recorded between the two treatment methods. One particular study showed differences only in VAS, ODI, and kyphosis, which was evaluated radiologically on the basis of Cobb angle, showing that internal fixation with percutaneous kyphoplasty was inferior to kyphoplasty alone. However, the bias of the above study was that the participants had an increased average of age (all > 65) and only burst fractures were evaluated [
Patients with osteoporotic fractures had poorer results in comparison with traumatic fractures. The main reason for the above is that osteoporotic patients are elderly with functional impairments, reduced bone quality, and muscular weakness. Even though it has been proven that in people over 50 most of the fractures are due to osteoporosis, compared to other parameters such as trauma, metastasis, and multiple myeloma [
The present study is the first that examines the entire spine, regarding both spinal curves and mobility, after surgical treatment of a fracture. In addition, this study evaluates the whole spine in two planes and compares all the parameters giving a comprehensive and complete picture of the postoperative patient’s status.
Both BKP and BKP plus fixation show significant early improvements regarding structure and mobility of the spine, especially in lumbar spine and Sac_Hip, which improve posture, balance, and QOL. At the same time they reduce deformities and limit the risk for a subsequent fall-related injury. In most of the parameters, there is a constant progress during reevaluations. Moreover, pain and disability reduce significantly and, combined with improvements in structure of the spine, cumulatively produce a clinically positive effect.
This study was conducted as part of a wider doctoral research.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Dr. Anastasia Topalidou carrying out the specific thesis receives scholarship from Alexander S. Onassis Public Benefit Foundation.