The effect of Providence night-time bracing on the sagittal profile in adolescent idiopathic scoliosis

PURPOSE

Adolescent idiopathic scoliosis (AIS) is characterized by coronal scoliosis and often a sagittal hypokyphosis. The effect of bracing on the sagittal profile is not well understood. The aim of this study is to assess the effect of night-time bracing on the sagittal profile in patients with AIS.

METHODS

We retrospectively included AIS patients with a main curve of 25-45° treated with a night-time brace in our institution between 2005 and 2018. Patients with estimated growth potential based on either Risser stage, hand X-rays, or menarchal status were included. Coronal and sagittal radiographic parameters were recorded at both brace- initiation and -termination. Patients were followed until surgery or one year after brace termination. Results were compared to a published cohort of full-time braced patients.

RESULTS

One hundred forty-six patients were included. Maximum thoracic kyphosis (TK) increased 2.5° (± 9.7) (p = 0.003), corresponding to a 3.5-fold relative risk increase post bracing in TK compared to a full-time brace cohort. Twenty-seven percent (n = 36) of the patients were hypokyphotic (T4/T12 < 20°) at brace initiation compared with 19% (n = 26) at brace termination (p = 0.134). All other sagittal parameters remained the same at follow-up. We found no association between progression in the coronal plane and change in sagittal parameters.

CONCLUSION

This is the first study to indicate that night-time bracing of AIS does not induce hypokyphosis. We found a small increase in TK, with a substantially lower risk of developing flat back deformity compared to full-time bracing. The coronal curve progression was not coupled to a change in TK.

Relation between sagittal pelvic and thoracolumbar parameters in supine position - Pelvic parameters and their predictive value for spinal Cobb angles

Introduction

Predicting the pre-morbid sagittal profile of the spine or segmental angles could enhance the process of planning the extent of fracture reduction. There is evidence that spinopelvic parameters may be suitable for this purpose.

Research question

Is it possible to determine the inflection point and the mono- and bi-segmental endplate angles (EPA) in the thoracolumbar transition (from Th9 to L2) based on age, gender, spinopelvic parameters, and the adjacent EPA in the supine position?

Material and methods

Based on Polytrauma CT scans in the supine position, the following spinopelvic parameters were measured using non-fractured spines: pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and the apex of the LL.

Results

In this study, a total of 287 patients with a mean age of 42±16 years were included. Age-related changes were observed, where LL, thoracic kyphosis (TK), and PI increase with age. Gender-related comparisons showed that females had a more pronounced LL and reduced TK. Significant correlations between IP and spinopelvic parameters, with the apex of LL providing the best prediction, were found. However, the overall model quality remained low. Predicting mEPA and bEPA showed positive correlations. The prediction for mEPA L2/3 demonstrated the highest correlation. For bisegmental angles, the most caudal bEPA (L2) exhibited the highest correlation, albeit with some notable absolute differences in the values between measured and predicted values.

Discussion and conclusion

While this study highlights the complexity of the relationship between the pelvis and thoracolumbar parameters, finding a predictive tool for thoracolumbar reduction and stabilization was not possible.

Validity of the Roussouly classification system for assessing distal junctional problems after long instrumented spinal fusion in degenerative scoliosis

PURPOSE

To evaluate the validity of the Roussouly classification system for assessing distal junctional problems (DJP) after long instrumented spinal fusion in degenerative scoliosis.

METHODS

Sixty-four patients with degenerative scoliosis and long-segment fixation receiving treatment at our hospital between December 2012 and December 2018 were retrospectively analyzed. Patients were classified preoperatively and postoperatively (Roussouly classification) and divided into DJP and control groups. We observed whether patients restored to their preoperative Roussouly classification (based on pelvic incidence [PI]) postoperatively.

RESULTS

The incidences of DJP were 11.11% and 50% in patients who did and did not match their sagittal Roussouly classification immediately postoperatively, respectively. The adjusted Chi-square test that showed whether the sagittal profile matched the Roussouly classification immediately after surgery was statistically significant (P = 0.012). PIs were 55.83 ± 4.94 and 47.21 ± 10.81 in the DJP and non-DJP groups, respectively (t' = 4.367, P < 0.001). Distal junctional kyphosis angles were 6.33 ± 4.19° and 11.56 ± 5.02° in the DJP and non-DJP groups, respectively (t = - 2.595, P = 0.015). Preoperative PI-lumbar lordosis values were 29.14 ± 13.82 and 16.67 ± 11.39 in the DJP and non-DJP groups, respectively (t = - 2.626, P = 0.013). The logistic regression model showed that patients whose Roussouly classification did not match the postoperative PI value were more likely to have DJP (odds ratio [OR] = 4.01, 95% confidence interval [CI]: 0.51-31.61) and preoperative distal junctional kyphotic changes.

CONCLUSION

If the postoperative sagittal profile can be restored to match the patient's own PI value, use of the Roussouly classification can greatly reduce the possibility of postoperative DJP.

The effects of vertebral body tethering on sagittal parameters: evaluations from a 2-years follow-up

INTRODUCTION

While the effects of VBT on coronal parameters have been investigated in various studies, this has not yet been the case for sagittal parameters. This is of particular relevance considering that VBT does not allow direct correction of the sagittal profile. Thus, we investigated the effects of VBT on sagittal parameters in patients with adolescent idiopathic scoliosis.

MATERIALS AND METHODS

Retrospective, 2-Center study. Patients who underwent VBT and presented a 2-years follow-up were included. The differences in sagittal parameters were evaluated, along with modifications of sagittal profile following Abelin-Genevois' classification.

RESULTS

Data from 86 patients were obtained. Mean Cobb angle was 52.4 ± 13.9° at thoracic level and 47.6 ± 14.3° at lumbar level before surgery, and 28.5 ± 13.6 and 26.6 ± 12.7° at the 2-year follow-up, respectively. Mean thoracic kyphosis increased from 28.3 ± 13.8 to 33 ± 13°, the lumbar lordosis (LL) was unvaried (from 47.5 ± 13.1 to 48.4 ± 13.5°), PT decreased from 9.4 ± 8.5 to 7.4 ± 6.1°, the sagittal vertical axis SVA decreased from 4.5 ± 31.4 to - 3.6 ± 27.9 mm. No kyphotic effect on LL in patients who underwent lumbar instrumentation was observed. Before surgery, 39 patients had a type 1 sagittal profile, 18 were type 2a, 14 type 2b and 15 type 3. Postoperatively, 54 were type 1, 8 were 2a, 13 were 2b and 11 were type 3.

CONCLUSIONS

VBT positively influences sagittal parameters and does not have a kyphotic effect on LL.

The effect of posterior compression of the facet joints for initial stability and sagittal profile in the treatment of thoracolumbar fractures: a biomechanical study

PURPOSE

Surgical treatment of thoracolumbar A3-fractures usually comprises posterior fixation-in neutral position or distraction-potentially followed by subsequent anterior support. We hypothesized that additional posterior compression in circumferential stabilization may increase stability by locking the facets, and better restore the sagittal profile.

METHODS

Burst fractures Type A3 were created in six fresh frozen cadaver spine segments (T12-L2). Testing was performed in a custom-made spinal loading simulator. Loads were applied as pure bending moments of ± 3.75 Nm in all six movement axes. We checked range of motion, neutral zone and Cobb's angle over the injured/treated segment within the following conditions: Intact, fractured, instrumented in neutral alignment, instrumented in distraction, with cage left in posterior distraction, with cage with posterior compression.

RESULTS

We found that both types of instrumentation with cage stabilized the segment compared to the fractured state in all motion planes. For flexion/extension and lateral bending, flexibility was decreased even compared to the intact state, however, not in axial rotation, being the most critical movement axis. Additional posterior compression in the presence of a cage significantly decreased flexibility in axial rotation, thus achieving stability comparable to the intact state even in this movement axis. In addition, posterior compression with cage significantly increased lordosis compared to the distracted state.

CONCLUSION

Among different surgical modifications tested, circumferential fixation with final posterior compression as the last step resulted in superior stability and improved sagittal alignment. Thus, posterior compression as the last step is recommended in these pathologies.

Discovering the association between the pre- and post-operative 3D spinal curve patterns in adolescent idiopathic scoliosis

BACKGROUND

The advantage of considering the three-dimensional curve patterns, including the patterns of the vertebral position and alignment, in classification of adolescent idiopathic scoliosis (AIS) patients and whether such classification system relates to the surgical outcomes are not fully determined.

METHODS

A total of 371 AIS patients who received posterior spinal fusion surgery with 2-year follow-up were included retrospectively and consecutively. The 3D positions and orientations of the T1-L5 vertebrae were calculated from the 3D reconstructions of the spines at pre-operative and 2-year follow-up, a total of 102 variables per patient. A probabilistic clustering method was used to cluster the pre-operative and 2-year follow-up 3D spinal curve patterns separately. The distributions of the Lenke types and 3D pre-operative clusters in the post-operative clusters were determined.

RESULTS

A total of nine pre-operative clusters including, four right thoracic types, three left thoracolumbar/lumbar types, one low apex right thoracic/thoracolumbar, and one left thoracic/right lumbar were determined. Three post-operative 3D curve patterns were Type 1 with higher residual proximal Cobb angle, Type 2 with lower T5-T12 kyphosis and highest pelvic incidence-lordosis mismatch, and Type 3 with larger lumbar curve magnitude and rotation compared to the other two groups. More than 50% of patients in each of the 3D pre-operative clusters had the same post-operative group.

CONCLUSION

We developed a 3D classification of the AIS patients before and two-year after spinal fusion surgery. The link between the pre- and post-operative clusters lends itself to application of this classification system in developing predictive models of the AIS surgical outcomes.

The sagittal curvature of the spine can be a leading cause of scoliosis in pediatric spine

The etiology of the adolescent idiopathic scoliosis (AIS) remains unknown. Variations in the sagittal profile of the spine between the early stage scoliotic and non-scoliotic pediatric patients have been shown. However, no quantitative study has shown the link between the sagittal profile and 3D deformity of the spine. 126 right thoracic scoliosis with spinal and 3D reconstructions were included. A 2D finite element model was developed for each of the sagittal curve types without any deformity in the frontal or axial planes. Physiological loadings were determined from the literature and were applied in the finite element model. The 3D deformation patterns of the models were compared to the 3D spinal patterns of the AIS with the same sagittal type. A significant correlation was found between the 3D deformity of the scoliotic curves and the numerical finite element simulation of the corresponding sagittal profile as determined by pattern correlation, p<0.001. The sagittal curve deformation patterns corresponded to the spinal deformities in the patients with the same sagittal curvature. Finite element models of the spines, representing different sagittal types in 126 AIS patients showed that deformation pattern of the sagittal types changes as a function of the spine curvature and associates with the patterns of 3D spinal deformity in AIS patients with the same sagittal curves. This finding provided evidence that the sagittal curve of the spine can determine the deformity patterns in AIS.

Sagittal curvature of the spine as a predictor of the pediatric spinal deformity development

BACKGROUND

The sagittal curvature of the spine is hypothesized to play an important role in induction of spinal deformities in adolescent idiopathic scoliosis. We previously showed an S shaped flexible rod, with the same curvature as the pediatric sagittal spinal curve, produces scoliotic-like deformities under physiologic loading. Yet, detailed characteristics of the pediatric sagittal spinal curves associated with higher risk of scoliosis are not well defined.

METHODS

A total of 32 patients in a population with a high prevalence of idiopathic-like scoliosis, 22q11.2 deletion syndrome (22q), were included and followed up for at least two-years. We developed a reduced order finite element model (FEM) of the sagittal profile of these 32 patients where the spine was modeled as an S shaped elastic rod. We related the geometrical parameters of the sagittal curves and the deformed FEM of the corresponding S shaped rods to the risk of scoliosis development at two-year follow-up in this cohort.

RESULTS

Variations in the sagittal curvature in the cohort of 22q patients resulted in five different deformity patterns shown by finite element analyses. Two sagittal plane deformity pattern groups had high rate of scoliosis development (86% and 100%) whereas the other 3 groups had less than 50% rate of scoliosis development (40%, 33%, and 0%). The pre-scoliotic position of the inflection point (where lordosis turns into kyphosis), the ratio of the spinal curvatures above and below the inflection point, and the length of the spinal curve above and below the inflection point were significantly different between the five deformity patterns groups, p < 0.05.

CONCLUSION

Combination of geometrical parameters of the sagittal profile prior to onset of scoliosis can relate to the development of spinal deformity in pediatric population.

How different the scoliotic curves are?

The pathomechanism of spinal deformity development in adolescent idiopathic scoliosis (AIS) has been related to the sagittal curvature of the spine. It is not known how the variations in the sagittal profile relates to the coronal deformity patterns in AIS. A total of 70 Lenke 1 and 50 Lenke 5 AIS patients were included retrospectively. A finite element (FE) model was developed for each spine where the sagittal spinal curvatures were modeled as 2D S shaped elastic rods. Transverse plane deformation patterns of these rods under physiological loading were determined and clustered based on their similarities. The patients' characteristics, including the Lenke type, and the spinal measurements in these deformation pattern clusters were statistically compared. Three different axial deformation patterns were determined from the FE simulations of the 120 sagittal curves. Two axial groups were looped shaped in opposing directions (Group I and III) and one was lemniscate shaped (Group II). 94% of the patients in Groups I and II were Lenke 1 and 100% of Group III was Lenke 5. The position of the sagittal inflection point moved downward from Group I-III resulting in significantly different ratio of the arc lengths above and below the sagittal inflection points for Groups I, II and III (0.49±0.59, 1.15±0.44, and 3.22±1.8). A classification of idiopathic scoliosis, based on the biomechanics of S-shaped flexible rods deformation could distinguish between different coronal curve types. The geometrical parameters of the sagittal profiles in the axial deformation pattern groups were significantly different.

A reduced-order model of the spine to study pediatric scoliosis

The S-shaped curvature of the spine has been hypothesized as the underlying mechanical cause of adolescent idiopathic scoliosis. In earlier work, we proposed a reduced-order model in which the spine was viewed as an S-shaped elastic rod under torsion and bending. Here, we simulate the deformation of S-shaped rods of a wide range of curvatures and inflection points under a fixed mechanical loading. Our analysis determines three distinct axial projection patterns of these S-shaped rods: two loop (in opposite directions) patterns and one Lemniscate pattern. We further identify the curve characteristics associated with each deformation pattern, showing that for rods deforming in a Loop1 shape the position of the inflection point is the highest and the curvature of the rod is smaller compared to the other two types. For rods deforming in the Loop2 shape, the position of the inflection point is the lowest (closer to the fixed base) and the curvatures are higher than the other two types. These patterns matched the common clinically observed scoliotic curves-Lenke 1 and Lenke 5. Our S-shaped elastic rod model generates deformations that are similar to those of a pediatric spine with the same sagittal curvature characteristics and it can differentiate between the clinically observed deformation patterns.

Reciprocal change of sagittal profile in unfused spinal segments and lower extremities after complex adult spinal deformity surgery including spinopelvic fixation: a full-body X-ray analysis

BACKGROUND CONTEXT

Few studies have described reciprocal changes of pathologic compensatory mechanisms in the setting of spinopelvic fixation using full-body radiograph.

PURPOSE

To elucidate how sagittal alignment of unfused spinal segments and lower extremities change reciprocally following complex thoracolumbar realignment surgery including fusion to the sacrum in adult spinal deformity.

STUDY DESIGN

Retrospective cohort.

PATIENT SAMPLE

Thirty-four patients who underwent fusion from lower thoracic to the sacrum/pelvis and 49 patients with fusion from upper thoracic to the sacrum/pelvis.

OUTCOME MEASURES

The postoperative sagittal alignment change, and the correlation between the instrumented spinopelvic alignment change and reciprocal changes in unfused spinal segments/lower extremities.

MATERIALS/METHODS

This study included 34 patients who underwent fusion from lower thoracic to the sacrum/pelvis (LT-P group) and 49 patients with fusion from upper thoracic to the sacrum/pelvis (UT-P group). The postoperative sagittal alignment changes were evaluated after subdividing the two groups according to T1 pelvic angle (TPA) (aligned group: TPA<20 and malaligned group: TPA>20). The correlation between the instrumented spinopelvic alignment change (ΔTPA and ΔLL), reciprocal changes in unfused spinal segments and lower extremities, and the cranial sagittal vertical axis-hip/ankle change (ΔCrSVA-Hip/Ankle) were also analyzed.

RESULTS

At the baseline in both LT-P and UT-P groups, the patients in the malaligned subgroups showed greater C2-7 lordosis (C2-7L), sacrofemoral angle (SFA), and knee flexion angle (KA) than those in the aligned subgroups. At average 7.1 months postoperatively, these compensatory mechanisms were restored in accordance with instrumented TPA/LL change, especially in the UT-P group. The mid-thoracic alignment changed significantly kyphotic in the LT-P group. ΔTPA and ΔLL linearly correlated with ΔC2-7L, ΔKA, and ΔAA in the malaligned patients. The multivariate regression analysis revealed that change in lower extremity parameters (ΔSFA, ΔKA, and ΔAA) independently impacted ΔCrSVA-Hip/Ankle.

CONCLUSION

Adequate thoracolumbar realignment surgery results in restoration of the pathologic compensatory mechanisms in the unfused spinal segments and lower extremities, especially in patients fused from upper thoracic spine. A preoperative clinical evaluation of the lower limb joints, as well as a full-body radiographic evaluation, is paramount to achieve optimal global sagittal balance in thoracolumbar realignment surgery.

[What is actually adult spinal deformity? : Development, classification, and indications for surgical treatment]

BACKGROUND

Adult spinal deformity (ASD) is a complex entity that has had emerging significance for spine surgeons in the last decade. Sagittal and/or coronary deformities can have a high impact (disability, pain) on the quality of patients' life. Radiologic diagnostics determine the common spinopelvic parameters as the basis for classification of ASD.

TREATMENT

Conservative treatment options may be sufficient in mild cases. The deformity's complexity frequently demands the entire spectrum of methods and techniques in spinal surgery. This article gives an overview on the development of the ASD, the correct classification as well as the indication for surgical therapy.

3D spinal and rib cage predictors of brace effectiveness in adolescent idiopathic scoliosis

Background

Scoliotic braces are the standard of curve for management of moderate spinal deformities in pediatric patients. The effectiveness of this treatment method has been shown; however, the spinal and rib cage parameters, in the three anatomical planes, that are associated with bracing outcome in adolescent idiopathic scoliosis (AIS) are not fully identified.

Methods

A total number of 45 right thoracic AIS patients who had received a thoraco-lumbo-scaral brace for the first time were included retrospectively. For each patient, radiographic images at three visits, pre-brace, in-brace, and at least 1 year after the first brace fit were included. Age, sex, Risser sign, and curve type at pre-brace, and thoracic and lumbar frontal and sagittal Cobb angles, thoracic and lumbar apical rotations, sagittal and frontal balances at pre-brace and in-brace were determined. Two sagittal curve types (hypothoracolumbar and normal/hyperthoracolumbar kyphosis), two rib cage types based on the costovertebral joints (drooping and horizontal), and two axial shapes of the spine (S shaped and V shaped) were used to stratify the patients. Feature selection and linear regression with regularization determined the parameters and the interaction terms that predicted the brace effectiveness significantly.

Results

Smaller in-brace thoracic Cobb and larger in-brace lordosis predicted brace effectiveness, p < 0.05. Impact of the out of brace lordosis on the brace success increased as the in brace kyphosis angle decreased, p = 0.046. A larger out of brace lordosis in hypothoracolumbar sagittal profile type patients improved the outcomes, p = 0.031. A smaller out of brace thoracic rotation improved the bracing outcomes in patients with horizontal ribs, p = 0.040.

Conclusion

Both 3D patient specific parameters (lordosis, thoracic rotation, shape of the rib cage, and sagittal profile) and brace design (which allows larger in brace lordosis, better in brace Cobb correction) are important predictors of the brace effectiveness in AIS.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2754-2) contains supplementary material, which is available to authorized users.

S1 Pedicle Subtraction Osteotomy in Sagittal Balance Correction. A Feasibility Study on Human Cadaveric Specimens

BACKGROUND

A cadaveric feasibility study was carried out. Osteotomies to correct fixed sagittal imbalance are usually performed at L₃/ L₄.

OBJECTIVE

To investigate the feasibility of S₁ pedicle subtraction osteotomy to correct spinal deformity and spinopelvic parameters, achieving better results with more limited exposure. The data obtained will allow a fixation construct specific for this osteotomy to be designed.

METHODS

S₁ pedicle subtraction osteotomy was performed on 12 cadaveric specimens. Baseline and postprocedural computed tomography and biomechanical studies were performed. Data were analyzed with a fixation system SolidWorks model, and the redesigned fixation construct was described and analyzed with an ANSYS model.

RESULTS

S₁ pedicle subtraction osteotomy is technically feasible. The fixation can be achieved with L₄, L₅, and iliac screws connected with bars. The system can be reinforced with a polyetheretherketone cage placed anteriorly in the S₁ body osteotomy site, a cross-connecting bar, a double iliac screw, or an anterior interbody cage placed at the L₅-S₁ disc. The fixation strength is improved by angulating the iliac rod channel 10°, adding a semi-sphere to the locking screw contact surface and 2 fins to its saddle. The redesigned construct showed suitable stress and deformation levels, achieving the expected biomechanical requirements.

DISCUSSION

Compared with surgery on higher levels, S₁ pedicle subtraction osteotomy allows greater correction with shorter fixation, because the osteotomy is performed at a more caudal level, modifying the spinopelvic parameters.

CONCLUSIONS

S₁ pedicle subtraction osteotomy is technically feasible. Finite element analysis results indicate that it has appropriate biomechanical properties.

Efficacy of three-dimensionally integrated exercise for scoliosis in patients with adolescent idiopathic scoliosis: study protocol for a randomized controlled trial

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is one of the most prevalent spinal deformities that may progress sharply during growth. The aim of this study will be to evaluate the efficacy of three-dimensionally integrated exercise on the Cobb angle, angle of trunk rotation, sagittal profile, and quality of life in patients with AIS.

METHODS/DESIGN

The study is designed as a randomized controlled trial. Participants include 42 patients with AIS aged 10-16 years. Randomly assigned patients will follow a 6-month treatment, either in a control group with standard care of observation following the Scoliosis Research Society criteria or in an experimental group with three-dimensionally integrated exercise for scoliosis. Blinded assessments at baseline and immediately after intervention will include the change of Cobb angle, angle of trunk rotation, sagittal index, and quality of life.

DISCUSSION

If we find that the intervention is effective in improving Cobb angle, angle of trunk rotation, sagittal profile, and quality of life in patients with AIS, this trial will have a positive impact and warrant a change in clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03427970 . Registered on February 9, 2018, and revised on July 24, 2018.

Pyogenic Spondylodiscitis of the Thoracic Spine: Outcome of 1-Stage Posterior Versus 2-Stage Posterior and Anterior Spinal Reconstruction in Adults

OBJECTIVE

The aim of this study was to compare the clinical, radiologic, and functional outcomes of a 1-stage posterior treatment versus a 2-stage posterior-anterior treatment in patients with pyogenic thoracic spondylodiscitis.

METHODS

A 1-stage posterior debridement, stabilization, and fusion with titanium-coated polyetheretherketone (PEEK) or mesh cage through a dorsolateral approach was performed in group A. A 2-stage procedure with initial posterior stabilization and debridement and second-stage fusion with a PEEK cage or mesh cage was performed with an anterior approach in group B. Clinical outcomes included Oswestry Low Back Pain Disability Questionnaire and visual analog scale score. Radiologic outcomes included fusion rate and kyphotic angle correction. Secondary variables included pathogens, complications, blood loss, and operative time.

RESULTS

One-level spondylodiscitis was treated surgically in the thoracic spine of 47 patients: 25 patients in group A and 22 patients in group B. The most frequent segment was T12-L1 (27%). There was a significantly longer operative time and greater blood loss (P > 0.001) in group B. At last follow-up, sagittal profile reconstruction was significantly better (P > 0.05) in group B. Both groups showed similar radiologic results with fusion in 92% of cases. Improved clinical outcomes, pain, and quality of life were achieved in both groups with no significant differences between the 2 groups.

CONCLUSIONS

Better reconstruction of the sagittal profile was achieved in the posterior-anterior-treated group, but this did not affect the clinical outcome. No significant differences were found in the clinical and functional outcomes between the 2 groups. Posterior-anterior combined treatment should be considered in cases of large anterior defects if a posterior reconstruction is inadequate.

[Frequency and age distribution of combined sternovertebral injuries : Analysis of routine data from German hospitals 2005-2012]

BACKGROUND

Combinations of sternal and spinal fractures often occur due to high velocity accidents and are associated with a high incidence of concomitant injuries. The anterior thoracic wall is described as the fourth column of torso stability, which is why sternovertebral injuries (SVI) present a high risk of sagittal deformation of the trunk, in particular injuries of the thoracic spine. To date, no studies have been published on the frequency distribution of the involved vertebral bodies in large patient groups.

OBJECTIVES

This study was intended to elaborate a frequency distribution of vertebral fractures accompanying sternal fractures (SF) and examine the risk of a vertebral fracture accompanying a SF.

MATERIAL AND METHODS

A total of 48,193 cases with the main or secondary diagnosis of a SF and 897,963 cases with vertebral fractures based on routine data of German hospitals from the years 2005-2012 were evaluated. A concomitant injury to the spinal column was examined for each vertebral body and then evaluated statistically.

RESULTS AND CONCLUSIONS

Of all patients with a SF 30.96% also suffered from a vertebral fracture. Of these 3.11% were SF as the main diagnosis and 60.89% the secondary diagnosis. While vertebral fractures generally occurred most frequently in the region of the thoracolumbar transition and the second cervical vertebral body, the SVI showed a further frequency peak in the range from the lower cervical spine to the middle thoracic spine. The present study was able to show a frequency distribution of accompanying vertebral body injuries in a large and representative collective in the case of SF for the first time.

Preoperative and postoperative sagittal plane analysis in adult idiopathic scoliosis in patients older than 40 years of age

BACKGROUND CONTEXT

Most of the papers correlate sagittal radiographic parameters with health-related quality of life (HRQOL) scores for patients with scoliosis. However, we do not know how changes in sagittal profile influence clinical outcomes after surgery in adult population operated for mainly frontal deformity.

PURPOSE

This study aimed to analyze spinal sagittal profile in a population operated on adult idiopathic scoliosis (AS) and to describe variations in sagittal parameters after surgery and the association between those variations and clinical outcomes.

DESIGN/SETTING

This is a historical cohort study.

PATIENT SAMPLE

We included in this study 40 patients operated on AS, older than 40 at the time of surgery (mean age 54.9), and with more than 2-year follow-up (mean 7.4 years).

OUTCOME MEASURES

Full-length free-standing radiographs, Scoliosis Research Society 22 (SRS22) and Short Form 36 (SF36) instruments, and satisfaction with outcomes were available at final follow-up.

METHODS

Sagittal preoperative and final follow-up radiographic parameters, radiographic correlation with HRQOL scores at final follow-up, and association between satisfaction and changes in sagittal profile were analyzed. A multivariate analysis was performed. No funds were received for this article.

RESULTS

Preoperatively, the spinal sagittal plane tended to exhibit kyphosis. Most sagittal parameters did not improve at final follow-up with respect to preoperative values. We saw, after univariate analysis, that worse sagittal profile leads to worse HRQOL, but after multivariate analysis, only spinal tilt (ST) persisted as possible predictor for worse SRS activity scores. Frontal Cobb significantly improved. Most patients (82%) were satisfied with final outcomes. Variations in sagittal profile parameters did not differ between satisfied and dissatisfied patients.

CONCLUSIONS

Although most sagittal plane parameters did not improve after surgery, surgical treatment in AS achieves a high satisfaction rate. Good clinical results do not correlate with improving sagittal plane parameters. Sagittal profile measurements are not helpful to decide surgical treatment in patients with mainly frontal deformity.

Segmental Pelvic Correlation (SPeC): a novel approach to understanding sagittal plane spinal alignment

BACKGROUND CONTEXT

Lumbar lordosis (LL) correlates with pelvic morphology, and it has been demonstrated that as LL increases, the inflection point and apex of lordosis move cranially. This suggests that each segment of the lumbar spine relates to pelvic morphology in a unique way.

OBJECTIVES

This study aimed to establish whether there is a direct relationship between pelvic morphology and lumbar segmental angulation in the sagittal plane.

STUDY DESIGN

A retrospective analysis of 41 patient radiographs was carried out.

PATIENT SAMPLE

Inclusion criteria included patients with full length standing anterioposterior and lateral radiographs of the spine from base of occiput to proximal femora, with clearly visible vertebral end plates from T12 to S1 and a thoracic kyphosis (TK) and LL within the normal range. Patients were excluded if they had a coronal spinal deformity affecting the lumbar spine, chronic back pain, spondylolisthesis, spondylolysis, congenital scoliosis, or skeletal dysplasia.

OUTCOME MEASURES

Spinopelvic radiographic parameters of pelvic incidence (PI), LL, TK, and segmental angulation at each level from L1 to the sacrum were the outcome measures.

METHODS

Forty-one lateral whole spine radiographs with normal sagittal profiles from the spinal deformity clinic were retrospectively reviewed. Pelvic incidence, LL, TK, and segmental angulation at each level from L1 to the sacrum were measured (from end plate to end plate), distinguishing the vertebral body and intervertebral disc contribution. Pearson correlation coefficients were used to analyze any relationship between pelvic parameters and segmental angulation.

RESULTS

A strong correlation was found between PI and LL. Pelvic incidence correlated strongly with the L1 and L2 motion segments (p=.0001, p=.03), notably at the intervertebral discs but not the L4 and L5 motion segments. The proportion of total LL contributed at L4-L5 and L5-S1 reduced as PI increased.

CONCLUSIONS

Pelvic incidence can predict segmental angulation. Although the majority of LL is produced at the L4 and L5 motion segments, cephalad lumbar segments sequentially become increasingly important as PI increases. This describes a continuum where the L1 and L2 motion segments crucially fine-tune total LL according to PI. This allows segmental abnormalities to be identified when compensation in adjacent segments maintain normal total LL. It also paves the way for anatomical segmental reconstruction in degenerative adult deformity based on pelvic morphology.

Importance of balance and profile in adult spinal reconstruction

Long before its current understanding, the concept of balance was common among spine surgeons dealing with deformities, but it was a hard one to transfer to clinical practice. Thanks to the pioneering work of Duval-Beaupere and followers, the idea of balancing the sagittal contour of the spine has gained scientific status and is now in the armamentarium of the skilled surgeon as the single most important tool to achieve superior clinical results in adult spinal deformity surgery.