Decrease In Thoracic Kyphosis Research Articles

Evaluation of the Effect of Halo Gravity Traction on Lung Volume in Advanced and Severe Kyphoscoliosis Patients in Chest Radiography

Aim: To evaluate the effect of preoperative halo gravity traction on lung volume in patients with advanced and rigid kyphoscoliosis using planimetric measurements from chest radiography. Method: Ten patients with a mean age of 20.5±0.9 with a diagnosis of severe and severe kyphoscoliosis who underwent halo gravity traction between 2019 and 2021 were included in our study. Direct chest radiographs taken before and after traction were analyzed retrospectively. In order to evaluate the effectiveness of traction, planimetric evaluations were made on radiographs. Results: In the evaluation of radiological parameters, mean thoracic coronal cobb angle, lumbar cobb angle, thoracic kyphosis angle, lumbar lordosis angle, C1-S1 distance and lung volume before and after the procedure were 96.670°±8.4535°, 88,090°±4.5989°, 37.020°±11.5893°, 38.540°±11.1269°, 73.150°±7.0412°, 65.590°±7.3927°, 59.100°±9.5467°, 55.100°±9.0238°, It was 371.590mm± 64.2410mm, 408.330 mm±80.8229 mm and 967.730 mm3±318.404 mm3, 1155.180mm3±332.868 mm3. The decrease in thoracic kyphosis, lumbar lordosis, thoracic cobb and lumbar cobb angles and the increase in lung volume and distance between C1-S1 were statistically significant (p<0.05). Conclusion: Traction application is a safe method for deformities. It is effective in correcting sagittal and coronal curvatures. It is a method that is effective in pulmonary functions as well as increasing the lung volume radiologically.

Compensation mechanisms for post-traumatic thoracolumbar kyphosis

Objective. To identify the mechanism of deformity compensation in patients with post-traumatic kyphosis of the thoracolumbar junction, based on the analysis of X-ray results of surgical treatment.Material and Methods. The study included data obtained from medical records of 69 patients (47 women, 22 men) operated on for painful post-traumatic kyphosis at the levels of T12, L1 and L2 vertebra. Patients underwent staged surgical interventions in a single surgical session. Demographic data and X-ray results of surgical treatment were evaluated.Results. As a result of surgical interventions, post-traumatic kyphosis (LK) was corrected to an average of 1.9°. After correction of kyphosis, statistically significant changes in the parameters of sagittal spinal curvatures were revealed: an increase in thoracic kyphosis (TK), a decrease in lumbar lordosis (LL), including due to lower lumbar lordosis (LowLL). At the same time, the parameters of the spinopelvic balance (PT, SS) did not change. Statistically significant correlations (p < 0.001) were detected between the magnitude of local kyphosis correction (LK preOP-LKpostOP), which amounted to 33.63° ± 8.77°, and parameters of lumbar lordosis ΔLL, thoracic kyphosis ΔTK and ΔPI-LL. Parameters of global sagittal balance and pelvic balance did not show correlations with the magnitude of kyphosis correction. The X-ray study of patients in Group I (without signs of initial sagittal imbalance) and Group II (with signs of sagittal imbalance) revealed a statistically significant difference in global balance (GT) and spinopelvic balance (PT, SS, LowLL), both before and after correction intervention in the thoracolumbar junction area, despite comparable indicators of sagittal spinal curvatures and the magnitude of post-traumatic kyphosis,.Conclusion. The main compensation mechanism includes changes in the spinal departments adjacent to kyphosis: a decrease in thoracic kyphosis and an increase in lumbar lordosis, rather than changes in the global or spinopelvic balance.

Postoperative proximal junctional kyphosis correlated with thoracic inlet angle in Lenke 5c adolescent idiopathic scoliosis patients following posterior surgery

BackgroundProximal junctional kyphosis is a common complication after posterior fusion in patients with adolescent idiopathic scoliosis and is correlated with postoperative changes of thoracic kyphosis. In lenke 5c patients, higher postoperative LL and spontaneous change of TK may produce an effect on final PJK. However, no studies has been performed to evaluate the correlation of PJK with thoracocervical parameters in patients with AIS.MethodsData from 98 patients who underwent posterior fusion for Lenke 5C AIS with 2 years of follow-up were retrospectively reviewed. Patients in the extended fusion group underwent fusion at levels higher than upper-end vertebra + 2 (n = 38), and those in the thoracolumbar/lumbar (TL/L) fusion group underwent fusion at UEV + 2 or lower (n = 60).ResultsDuring an average follow-up of 38.1 months, 23 of 98 patients developed PJK. The extended fusion group had a higher incidence of PJK than the TL/L fusion group (14/38 vs. 9/60, respectively; P = 0.01) and a significantly greater decrease in thoracic kyphosis than the TL/L group (P < 0.01). Patients with PJK had a significantly larger preoperative thoracic inlet angle (TIA) than those without PJK (P < 0.01). Multivariate analysis showed that a greater preoperative TIA and extended fusion were associated with PJK. The Scoliosis Research Society 22-item questionnaire score did not significantly differ between the PJK and non-PJK groups.ConclusionsThe preoperative TIA could be a predictor of PJK. Among patients with Lenke 5C AIS, those with a TIA of > 71° are more likely to develop PJK. Additionally, extended fusion in patients with Lenke 5C may increase the risk of PJK.

Compensatory mechanisms in adult degenerative thoracolumbar spinal deformity - Radiographic patterns, their reversibility after corrective surgery, and the influence of pelvic morphology.

Loss of lumbar lordosis (LL) in degenerative deformity activates spinal compensatory mechanisms to maintain neutral C7 sagittal vertical axis (C7SVA), such as an increase in pelvic tilt (PT) and decreased thoracic kyphosis (TK). We study the extent to which PT increase and TK reduction contribute to the compensation of pelvic incidence (PI)-LL mismatch. A cohort of 43 adult patients with adult degenerative thoracolumbar deformity were included in this retrospective study. Radiographic spinopelvic measurements were obtained before and after corrective surgery. Pearson correlations were calculated. Preoperative PI-LL mismatch significantly correlated with an increase in PT and a decrease in TK in the whole cohort r = +0.66 (95% confidence interval [CI] 0.44-0.8) and r = -0.67 (95% CI - 0.81--0.47), respectively, at a relative rate of 0.37 (standard deviation [SD]: 0.07) and - 0.57 (SD: 0.09), respectively. In patients with low PI, only TK showed a significant correlation with PI-LL mismatch, r = -0.56 (95% CI - 0.8 to - 0.16), at a rate of - 0.57 (SD: 0.19). The high PI subgroup showed a significant correlation with PT, TK, and C7SVA, r = 0.62 (95% CI 0.26-0.82), r = -0.8 (95% CI - 0.9--0.58), and r = 0.71 (95% CI 0.41-0.87) at rates of 0.48 (SD: 0.11), -0.72 (SD: 0.12), and 0.62 (SD: 1.27). Decreased TK represented a more consistent compensatory mechanism in patients with high and low PI when compared to an increase in PT. PI-LL mismatch induced more pronounced changes in TK than did PT in both subgroups. Patients with high PI relied more on increases in PT and a relative decrease in TK to compensate for PI-LL mismatch than patients with low PI.

Thoracic kyphosis in light of lumbosacral alignment in thoracic adolescent idiopathic scoliosis: recognition of thoracic hypokyphosis and therapeutic implications

BackgroundThe uniqueness of spinal sagittal alignment in thoracic adolescent idiopathic scoliosis (AIS), for example, the drastically smaller thoracic kyphosis seen in some patients, has been recognized but not yet fully understood. The purpose of this study was to clarify the characteristics of sagittal alignment of thoracic AIS and to determine the contributing factors.MethodsWhole spine radiographs of 83 thoracic AIS patients (73 females) were analyzed. The measured radiographic parameters were the Cobb angle of thoracic scoliosis, thoracic kyphosis (TK), lumbar lordosis (LL), C7 sagittal vertical axis (C7 SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Additionally, max-LL, which was defined as the maximum lordosis angle from the S1 endplate, the inflection point between thoracic kyphosis and lumbar lordosis, and the SVA of the inflection point (IP SVA) were measured. The factors significantly related to a decrease in TK were assessed by stepwise logistic regression analysis. In addition, cluster analysis was performed to classify the global sagittal alignment.ResultsThe significant factors for a decrease in TK were an increase in SS (p = 0.0003, [OR]: 1.16) and a decrease in max-LL (p = 0.0005, [OR]: 0.89). According to the cluster analysis, the global sagittal alignment was categorized into the following three types: Type 1 (low SS, low max-LL, n = 28); Type 2 (high SS, low max-LL, n = 22); and Type 3 (high SS, high max-LL, n = 33).ConclusionsIn thoracic AIS, a decreased TK corresponded to an increased SS or a decreased max-LL. The sagittal alignment of thoracic AIS patients could be classified into three types based on SS and max-LL. One of these three types includes the unique sagittal profile of very small TK.

Sagittal Plane Deformities in Children with SMA2 following Posterior Spinal Instrumentation

This is a retrospective radiographic review to assess post-operative sagittal plane deformities in patients with Spinal Muscular Atrophy type 2 that had been treated with posterior spinal instrumentation. Thirty-two patients with a history of either spinal fusion (N = 20) or growing rods (N = 12) were identified with an average of 7.6 (2.1–16.6) years post-operative follow-up. Forty percent (13/32) of the patients were identified as having obvious “tucked chin” (N = 4), “tipped trunk” (N = 9), or both (N = 3). Sacral incidence was the only parameter that was statistically significant change between pre-operative or immediate post-operative measurements (66.9° vs. 55.2° p = 0.03). However, at final follow-up, the post-operative thoracic kyphosis had decreased over time in those that developed a subsequent sagittal deformity (24.2°) whereas it increased in those that did not (44.7°, p = 0.008). This decrease in thoracic kyphosis throughout the instrumented levels, resulted in a greater lordotic imbalance (30.4° vs. 5.6°, p = 0.001) throughout the instrumented levels in the group that developed the subsequent cervical or pelvic sagittal deformities. In conclusion, sagittal plane deformities commonly develop outside the instrumented levels in children with SMA type 2 following posterior spinal instrumentation and may be the result of lordotic imbalance that occurs through continued anterior growth following posterior instrumentation.

How helpful is the halo-gravity traction in severe spinal deformity patients?: A systematic review and meta-analysis.

This study sought to evaluate the complications and clinic outcome in radiographic parameters, pulmonary function, and nutritional status of halo-gravity traction (HGT) in treating severe spinal deformity. Embase, PubMed, Cochrane, Web of Science databases were searched comprehensively for relevant studies from inception to February 2021, by using combined text and MeSH terms and English language restriction was used. The data, including radiographic parameters, pulmonary function (FVC %), and nutritional status (BMI) was extracted from included studies. All meta-analyses were conducted using random or fixed-effects models according the between-study heterogeneity, estimated with I2. Four hundred and forty-six studies were identified and twelve studies with a total of 372 patients were included in this review. Compared with pre-traction values, there were reduction in cobb angle of 28.12° [95% CI (22.18, 34.18)], decrease in thoracic kyphosis of 26.76°[95% CI (20.73, 32.78)], improvements in spine height[SMD = -0.89, 95% CI (- 1.56, - 0.21)] and in coronal balance[WMD = - 0.03, 95% CI (- 1.56, - 0.21), P = 0.84] with preoperative halo-gravity traction for severe spinal deformity patients. Besides, our pooled analysis showed the improvement in pulmonary function (FVC %) [WMD = - 9.56, 95% CI (- 1.56, - 0.21)] and increase in nutritional status (BMI) [WMD = - 0.50, 95% CI (- 1.56, - 0.21)]. Partial correction can be achieved by preoperative HGT, thereby reducing the difficulty of the operation and the risk of neurologic injury caused by excessive correction. Moreover, preoperative HGT can improve pulmonary function and nutritional status and, thus, increase patients' tolerance to surgery.

Vertebral Coplanar Alignment Technique Versus Bilateral Apical Vertebral Derotation Technique in Neuromuscular Scoliosis.

Single-center retrospective analysis of prospectively collected data. Our aim was to compare the correction capacity in 3 planes of the VCA technique versus the AD technique in neuromuscular scoliosis patients. We analized patients with neuromuscular scoliosis that underwent posterior spinal fusion from 2013 to 2017 using 2 different techniques for correction: vertebral coplanar alignment (VCA) that takes into consideration the fact that the medial cortex is more resistant than the lateral cortex, with more anchor points for better distribution of forces and ligamentotaxis and the more widely spread apical derotation (AD) technique. Clinical, surgical, and radiographic information of patients operated on with the AD technique were compared to those operated on with the VCA technique in the coronal, sagittal and axial plane at pre-op, immediate post-op, and 2 year follow-up. 64 patients met inclusion criteria, 34 patients underwent the VCA technique and 30 patients underwent the AD technique. The 2 cohorts did not differ in terms of demographics, clinical presentation or preoperative alignment. There were no significant differences in the correction ability between both techniques regarding curve magnitude, apical vertebral rotation, or pelvic obliquity. There was a significant decrease in thoracic kyphosis in the AD group compared to the VCA group in the immediate postop period (4.2 ± 26.6º for VCA and 13.2 ± 21.3º for AD (p = 0.048)). Both apical derotation technique and vertebral coplanar alignment allow for correction in the 3 planes for patients with neuromuscular scoliosis. VCA is a less hypokyphosing technique than AD.

Relationship of back muscle and knee extensors with the compensatory mechanism of sagittal alignment in a community-dwelling elderly population

Compensatory mechanisms, such as a decrease in thoracic spine kyphosis and posterior tilting or rotation of the pelvis, aim to achieve optimal alignment of the spine. However, the effect of muscle strength on these compensatory mechanisms has not been elucidated. This study aimed to investigate the impact of back muscle and lower extremity strength on compensatory mechanisms in elderly people. Overall, 409 community-dwelling elderly participants (164 men, 245 women) were included. Age, disc degeneration, and 2 or more vertebral fractures showed a significant increase of risk for sagittal vertical axis (SVA) deterioration. Conversely, stronger back, hip flexor, and knee extensor muscles reduced the risk for SVA deterioration. To investigate the association of each muscle’s strength with compensatory mechanisms, 162 subjects with pelvic incidence-lumbar lordosis > 10° were selected. The linear regression model for thoracic kyphosis demonstrated a negative correlation with back muscle strength and positive correlation with vertebral fracture. The regression analysis for pelvic tilt demonstrated a positive correlation with knee extensor strength. Back, hip flexor, and knee extensor muscle strength were associated with sagittal spinal alignment. Back muscle strength was important for the decrease in thoracic kyphosis, and knee extensor strength was associated with pelvic tilt.

Analysis of the Change Patterns of Sagittal Alignment Values After Selective Thoracic Fusion in Lenke 1 Adolescent Idiopathic Scoliosis According to Preoperative Thoracic Kyphosis Status

This was a retrospective study. The objective of this study was to demonstrate the different change patterns in reciprocal sagittal alignment values after selective thoracic fusion (STF) in Lenke type 1 adolescent idiopathic scoliosis (AIS) according to preoperative thoracic kyphosis (TK). Several studies have found significant increase in TK after STF, while other studies have reported decrease in TK postoperatively. Similar inconclusive results on changes in lumbar lordosis (LL) have been reported, showing LL increase, decrease, or no change. Ninety-three patients presenting with Lenke type 1 AIS treated by posterior STF with a minimum follow-up of 2 years were included in this study. Using whole spine radiographs, sagittal parameters including TK, LL, and upper lumbar lordosis (ULL) were compared preoperatively and at the last follow-up between a hypokyphosis group (preoperative TK<20 degrees) and a normokyphosis group (preoperative TK≥20 degrees). Health-related quality of life (HRQOL) was assessed using scoliosis research society health-related quality of life-30 (SRS-30) and short from health survey-36 questionnaire at the last visit. The mean follow-up duration was 74.9 months. In the hypokyphosis group (35 patients), TK, LL, and ULL statistically significantly increased after surgery by mean 7.7, 5.1, and 3.7 degrees (P<0.001, <0.001, and 0.001). In the normokyphosis group (58 patients), these parameters did not show significant changes after STF. Final TK was significantly lower in hypokyphosis group than that in the normokyphosis group (21.2 vs. 30.9 degrees, P<0.001) while final LL did not differ between 2 groups (52.4 vs. 54.6 degrees, P=0.194). HRQOL did not differ significantly between the 2 groups. After STF in Lenke 1 AIS, TK, and LL statistically significantly increased through an increase in the mean ULL in the hypokyphosis group while those mean values did not change in the normokyphosis group. Despite the final mean value of the TK in the hypokyphosis group increasing by 7.7 degrees, it was statistically significantly lower than the final mean TK value in the normokyphosis group which did not increase after STF surgery by posterior approach. However, HRQOL showed no significant difference between the 2 groups.

Concurrent Validity of Digital Image-based Postural Assessment as a Method for Measuring Thoracic Kyphosis: A Cross-Sectional Study of Healthy Adults

ObjectiveTo analyze the concurrent validity of the Digital Image-based Postural Assessment (DIPA) method for identifying the magnitude and classification of thoracic kyphosis in adults. MethodologyOn the same day and in the same place, thoracic kyphosis was assessed in 68 adults using 2 methods: the DIPA software protocol and radiography. The DIPA software provided angular values of thoracic kyphosis based on trigonometric relations, while with the radiograph, the curvature was calculated using the Cobb method. The following tests were applied in the statistical analysis: Pearson's correlation, Bland-Altman's graphic representation, root mean square error, and receiver operating characteristic (ROC) curve; α = 0.05. The reference angular values for the standard thoracic posture used in DIPA were determined with the ROC curve based on the Cobb angles. ResultsThe correlation between the angles obtained for thoracic kyphosis using the DIPA and Cobb methods was found to be high (r = 0.813, P < .001), and the accuracy was ±4°. According to Bland-Altman's representation, the magnitudes provided by the DIPA software were in agreement with those of the Cobb method. In reference values for determining the standard posture of the thoracic spine, the ROC curve indicated good accuracy in diagnosing a decrease in thoracic kyphosis (with a value of 33.9°) and excellent accuracy in diagnosing thoracic hyperkyphosis (with a value 39.9°) when using DIPA. ConclusionThe DIPA postural assessment method is valid in the sagittal plane for identifying the magnitude of thoracic kyphosis in adults. Furthermore, it is accurate in diagnosing alterations in thoracic kyphosis.

NATURAL HISTORY OF LUMBAR CANAL STENOSIS: CLINICAL ASPECTS AND SAGITTAL BALANCE

ABSTRACT Objective To compare the sagittal alignment (SA) parameters in individuals with LCS and surgical indication with a control group and to study the correlations between SA parameters and ODI, VAS and EQ-5D in individuals with LCS and surgical indication. Methods In this multicenter cross-sectional case-control study, the individuals were allocated as follows. A stenosis group (SG) composed by patients with LCS confirmed by magnetic resonance imaging with surgical indication, treated between July 2010 and August 2016 and a control group (CG), without LCS. All subjects underwent anamnesis, completed the Health-related Quality of Life (HRQoL) and total spine radiographs were taken. Clinical data, HRQoL and radiographic parameters were correlated. Results Sixty-four individuals formed the SG and 14 the CG. The SG had higher values of mean age, coronal imbalance, sagittal vertical axis (SVA), pelvic tilt (PT), sacrofemoral distance (SFD), overhang (OH), PI-LL mismatch, Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for pain and smaller thoracic kyphosis (TK), total (TLPL) and regional lumbopelvic lordosis (RLPL) in all vertebrae, sagittal offset (SO) in all evaluated vertebrae and EuroQol-5D (EQ-5D) with p &lt;0.05. In the SG, the only significant correlations (p &lt;0.05) were between TK and ODI and EQ-5D; all the other sagittal parameters did not correlated with VAS, ODI or EQ-5D. Conclusion SG had SA parameters altered in relation to CG. There was a direct correlation between decrease in TK and worsening of ODI and EQ-5D in SG. Level of evidence: III; Case Control Study.

Sagittal plane assessment of spino-pelvic complex in a Central European population with adolescent idiopathic scoliosis: a case control study

BackgroundScoliosis is a complex three-dimensional deformity. While the frontal profile is well understood, increasing attention has turned to balance in the sagittal plane. The present study evaluated changes in sagittal spino-pelvic parameters in a large Hungarian population with adolescent idiopathic scoliosis.MethodsEOS 2D/3D images of 458 scoliotic and 69 control cases were analyzed. After performing 3D reconstructions, the sagittal parameters were assessed as a whole and by curve type using independent sample t test and linear regression analysis.ResultsPatients with scoliosis had significantly decreased thoracic kyphosis (p < 0.001) with values T1–T12, 34.1 ± 17.1o vs. 43.4 ± 12.7o in control; T4–T12, 27.1 ± 18.8o vs. 37.7 ± 15.1o in control; and T5–T12, 24.9 ± 15.8o vs. 32.9 ± 15.0o in control. Changes in thoracic kyphosis correlated with magnitude of the Cobb angle (p < 0.001). No significant change was found in lumbar lordosis and the pelvic parameters. After substratification according to the Lenke classification and individually evaluating subgroups, results were similar with a significant decrease in only the thoracic kyphosis. A strong correlation was seen between sacral slope, pelvic incidence, and lumbar lordosis, and between pelvic version and thoracic kyphosis in control and scoliotic groups, whereas pelvic incidence was also seen to be correlated with thoracic kyphosis in scoliosis patients.ConclusionAdolescent idiopathic scoliosis patients showed a significant decrease in thoracic kyphosis, and the magnitude of the decrease was directly related to the Cobb angle. Changes in pelvic incidence were minimal but were also significantly correlated with thoracic changes. Changes were similar though not identical to those seen in other Caucasian studies and differed from those in other ethnicities. Scoliotic curves and their effect on pelvic balance must still be regarded as individual to each patient, necessitating individual assessment, although changes perhaps can be predicted by patient ethnicity.

The Relationship Between Cervical Degeneration and Global Spinal Alignment in Patients With Adult Spinal Deformity.

To examine the relationship between cervical degeneration and spinal alignment by comparing patients with adult spinal deformity versus the control cohort. The effect of degeneration on cervical alignment has been controversial. Cervical and full-length spine radiographs of 57 patients with adult spinal deformity and 78 patients in the control group were reviewed. Adult spinal deformity was classified into 3 types based on the primary characteristics of the deformity: "Degenerative flatback" group, "Positive sagittal imbalance" group, and "Hyperthoracic kyphosis" group. Cervical degeneration was assessed using the cervical degeneration index scoring system. The "Degenerative flatback" group had significantly higher total cervical degeneration index score (25±7) than the control group (16±8), the "Positive sagittal imbalance" group (18±8), and the "Hyperthoracic kyphosis" group (12±7) (P<0.01). The "Degenerative flatback" group had significantly less cervical lordosis than the other groups. This reduced amount of cervical lordosis was thought to be induced by a compensatory decrease in thoracic kyphosis. In this group, increased cervical degeneration was significantly associated with a decrease in cervical lordosis. Significantly greater compensatory increase in cervical lordosis was noted in the "Positive sagittal imbalance" group (20±15 degrees) and the "Hyperthoracic kyphosis" group (26±9 degrees) compared with the control group (11±12 degrees) (P<0.02). Flat cervical spine coexisted with cervical degeneration when compensatory hypothoracic kyphosis was induced by degenerative flatback. In other situations, cervical lordosis could increase as a compensatory reaction against sagittal imbalance or hyperthoracic kyphosis.

The Influence of the "Straighten Your Back" Command on the Sagittal Spinal Curvatures in Children with Generalized Joint Hypermobility.

Objectives. The aim of the study was to assess the change of sagittal spinal curvatures in children with generalized joint hypermobility (GJH) instructed with “straighten your back” command (SYB). Methods. The study included 56 children with GJH. The control group consisted of 193 children. Sacral slope (SS), lumbar lordosis (LL), global thoracic kyphosis (TK), lower thoracic kyphosis (LK), and upper thoracic kyphosis (UK) were assessed with Saunders inclinometer both in spontaneous positions (standing and sitting) and after the SYB. Results. Children with GJH after SYB presented the following: in standing, increase in SS and decrease in TK, LK, and UK (P < 0.01), with LL not significantly changed; in sitting: decrease in global thoracic kyphosis (35.5° (SD 20.5) versus 21.0° (SD 15.5), P < 0.001) below the standards proposed in the literature (30–40°) and flattening of its lower part (P < 0.001). The same changes were observed in the control group. Conclusions. In children with generalized joint hypermobility, the “straighten your back” command leads to excessive reduction of the global thoracic kyphosis and flattening of its lower part. Therefore, the “straighten your back” command should not be used to achieve the optimal standing and sitting positions.

A Uniquely Shaped Rod Improves Curve Correction in Surgical Treatment of Adolescent Idiopathic Scoliosis.

A retrospective cohort study. The aim of this study is to determine the initial curve correction in patients surgically treated for adolescent idiopathic scoliosis (AIS) using either beam-like rods (BRs) or traditional circular rods (CRs). Posterior fusion using all pedicle screw instrumentation has become the standard for the surgical treatment of AIS. Traditionally, the rod is circular in the cross-sectional plane. Recent biomechanical studies suggest that a beam-like structure of the rod may enhance the stiffness of the construct and thereby possibly improve curve correction. Two consecutive series of patients surgically treated for AIS between May 2011 and May 2015 were included in the study. Patients were all treated with an ultralow profile all-pedicle screw implant system. In the first series, conventional 5.5 mm CoCr CR were used, and in the second series, 5.5 mm CoCr BR were used. Antero-posterior and lateral radiographs preoperatively and within seven days after surgery were used to measure the correction obtained. The first 60 patients were operated with CR and the subsequent 69 with BR. There was no statistical difference in age, gender, preoperative curve magnitude, Lenke type, or number of levels instrumented (P = 0.451). Major curve correction was significantly better in the BR group than in the CR group (66 vs. 57%) (P < 0.001). We found no difference in preoperative flexibility, secondary curve correction, sagittal balance, or coronal balance (P > 0.058). A postoperative decrease in thoracic kyphosis was seen with no significant difference between groups. Median T5-T12 change was -7° versus -3° for BR and CR, respectively (P = 0.051). A BR design results in a significantly better curve correction than conventional rods, but the difference is moderate and the clinical value is uncertain. 3.

Body Mass Index as an Indicator of Pulmonary Dysfunction in Patients With Adolescent Idiopathic Scoliosis

Prospective clinical study. To investigate the factors correlated with pulmonary function in adolescent idiopathic scoliosis (AIS) patients, and to determine the influence of body mass index (BMI) on the pulmonary function. Impaired pulmonary function has been reported in patients with AIS. The factors reported to affect pulmonary function included the curve magnitude, location of the apex vertebrae, decrease in thoracic kyphosis, and the number of vertebrae involved. A low BMI has been well confirmed in AIS patients. However, the relationship between BMI and pulmonary function has never been investigated. One hundred twenty female patients with a single thoracic curve were enrolled in this study. Pulmonary function test and radiographic examination were performed. Several radiographic parameters, including the curve magnitude, the curve type, location of the apical vertebra, the number of vertebrae involved, and the degree of thoracic kyphosis, were recorded. BMI was calculated according to the measurements of standing height and body weight. Patients were divided into 2 groups according to BMI, (group A >17.5 kg/cm and group B ≤17.5 kg/cm), and the pulmonary function was compared between the 2 groups with students t test. Partial correlation analysis and stepwise multiple regression analysis were used to assess the association between BMI and the results of the pulmonary function test. The receiver operating characteristics curve was created to identify the best dividing point for diagnostic variables. The average percentage of predicted vital capacity, forced vital capacity, and forced expiratory volume in 1 second was significantly decreased in patients with a lower BMI. A positive correlation was found between BMI and pulmonary function (r=0.41, P<0.001). The stepwise regression analysis showed that low BMI was significantly associated with pulmonary function impairment (R=0.206, P<0.001). According to the receiver operating characteristics curve, patients with a BMI <17.7 kg/cm are prone to have abnormal pulmonary function. BMI was found to be an important indicator for pulmonary function in AIS patients. The decreased BMI could explain approximately one-fifth of the variation in pulmonary impairment in AIS patients, which might shed some light on the rehabilitation of preoperative pulmonary function.

Main thoracic curve adolescent idiopathic scoliosis: association of higher rod stiffness and concave-side pedicle screw density with improvement in sagittal thoracic kyphosis restoration.

The aim of this study was to evaluate the effects of rod stiffness and implant density on coronal and sagittal plane correction in patients with main thoracic curve adolescent idiopathic scoliosis (AIS). The authors conducted a retrospective study of 77 consecutive cases involving 56 female and 21 male patients with Lenke Type 1 main thoracic curve AIS who underwent single-stage posterior correction and instrumented spinal fusion with pedicle screw fixation between July 2009 and July 2012. The patients' mean age at surgery was 15.79 ± 3.21 years. All patients had at least 1 year of follow-up. Radiological parameters in the coronal and sagittal planes, including Cobb angle of the major curve, side-bending Cobb angle of the major curve, thoracic kyphosis (TK), correction rates, and screw density, were measured and analyzed. Screw densities (calculated as number of screws per fusion segment × 2) of < 0.60 and ≥ 0.60 were defined as low and high density, respectively. Titanium rods of 5.5 mm and 6.35 mm diameter were defined as low and high stiffness, respectively. Patients were divided into 4 groups based on the type of rod and density of screw placement that had been used: Group A, low-stiffness rod with low density of screw placement; Group B, low-stiffness rod with high density of screw placement; Group C, high-stiffness rod with low density of screw placement; Group D, high-stiffness rod with high density of screw placement. The mean coronal correction rate of the major curve, for all 77 patients, was (81.45% ± 7.51%), and no significant difference was found among the 4 groups (p > 0.05). Regarding sagittal plane correction, Group A showed a significant decrease in TK after surgery (p < 0.05), while Group D showed a significant increase (p < 0.05); Group B and C showed no significant postoperative changes in TK (p > 0.05). The TK restoration rate was highest in Group D and lowest in Group A (A, -39.32% ± 7.65%; B, -0.37% ± 8.25%; C, -4.04% ± 6.77%; D, 37.59% ± 8.53%). Screw density on the concave side was significantly higher than that on the convex side in all the groups (p < 0.05). For flexible main thoracic curve AIS, both rods with high stiffness and those with low stiffness combined with high or low screw density could provide effective correction in the coronal plane; rods with high stiffness along with high screw density on the concave side could provide better outcome with respect to sagittal TK restoration.

Morphometric analysis of variation in the ribs with age and sex.

Rib cage morphology changes with age and sex are expected to affect thoracic injury mechanisms and tolerance, particularly for vulnerable populations such as pediatrics and the elderly. The size and shape variation of the external geometry of the ribs was characterized for males and females aged 0-100years. Computed tomography (CT) scans from 339 subjects were analyzed to collect between 2700 and 10400 homologous landmarks from each rib. Rib landmarks were analyzed using the geometric morphometric technique known as Procrustes superimposition. Age- and sex-specific functions of 3D rib morphology were produced representing the combined size and shape variation and the isolated shape variation. Statistically significant changes in the size and shape variation (P<0.0001) and shape variation (P<0.0053) of all 24 ribs were found to occur with age in males and females. Rib geometry, location, and orientation varied according to the rib level. From birth through adolescence, the rib cage experienced an increase in size, a decrease in thoracic kyphosis, and inferior rotation of the ribs relative to the spine within the sagittal plane. From young adulthood into elderly age, the rib cage experienced increased thoracic kyphosis and superior rotation of the ribs relative to the spine within the sagittal plane. The increased roundedness of the rib cage and horizontal angling of the ribs relative to the spine with age influences the biomechanical response of the thorax. With the plane of the rib oriented more horizontally, loading applied in the anterior-posterior direction will result in increased deformation within the plane of the rib and an increased risk for rib fractures. Thus, morphological changes may be a contributing factor to the increased incidence of rib fractures in the elderly. The morphological functions derived in this study capture substantially more information on thoracic skeleton morphology variation with age and sex than is currently available in the literature. The developed models of rib cage anatomy can be used to study age and sex variations in thoracic injury patterns due to motor vehicle crashes or falls, and clinically relevant changes due to chronic obstructive pulmonary disease or other diseases evidenced by structural and anatomic changes to the chest.

Effect of direct vertebral body derotation on the sagittal profile in adolescent idiopathic scoliosis

We sought to clarify the effect of applying derotation maneuvers in the correction of adolescent idiopathic scoliosis (AIS) on the sagittal plane. We retrospectively queried a large, multicenter, prospectively collected database for patients who underwent surgical correction of AIS. All patients had at least 2 years of follow-up and documentation as to whether or not a derotation maneuver was performed during surgery. All patients underwent posterior spinal fusion with pedicle screw constructs. Patients who underwent concurrent anterior procedures were excluded. A total of 323 patients were identified, of whom 66 did not have direct vertebral body derotation (DVBD) maneuvers applied during the deformity correction. The remaining 257 had a vertebral body derotation maneuver performed during their surgical correction. Although no significant differences were identified between the two groups when comparing pre-op and post-op thoracic kyphosis using T2-12 and T5-12 endplates, the absolute change in angulation measured from T2-12 was significantly different between the two groups. Postoperatively, the derotation group had a mean decrease in thoracic kyphosis of 5.1±15.3° as compared to 10.8±18.9° in the control group, P = 0.03. Although patients in both groups had decreased mean thoracic kyphosis postoperatively, application of DVBD in the correction of scoliosis did not additionally worsen the sagittal profile.