Effect of morphological changes in the sagittal plane of vertebrae and discs on degenerative kyphodeformity / 中国骨伤

OBJECTIVE@#To explore the effects of morphological changes such as vertebral wedge deformation and disc degeneration (collapse) on adult thoracolumbar/lumbar degenerative kyphosis(TL/LDK) deformity.@*METHODS@#A retrospective analysis of 32 patients with spinal TL/LDK deformity admitted from August 2015 to December 2020, including 8 males and 24 females, aged 48 to 75(60.3±12.4) years old. On the long-cassette standing upright lateral radiographs, the coronal Cobb angle, sagittal thoracic lumbar/lumbar kyphosis angle(KA) of spine were measured, and the height and wedge parameters of apex vertebral(AV) and two vertebrae(AV-1, AV-2, AV+1, AV+2) above and below AV and the intervertebrae and the intervertebral disc(AV-1D, AV-2D, AV+1D, AV+2D) were evaluated, involving anterior vertebral body height(AVH), posterior vertebral body height(PVH), vertebral wedge angle(VWA), ratio of vertebral wedging(RVW), anterior disc height(ADH), posterior disc height(PDH), disc wedge angle(DWA), ratio of disc wedging(RDW), and DWA/KA.@*RESULTS@#The average angle of kyphosis was (44.2±19.1)°. A significant decrease in anterior height of vertebral was observed compared to the posterior height of vertebral(P<0.005). There was no significant difference in anterior and posterior height of discs. The vertebral wedging ratio/contribution ratio:AV-2(14.98±10.95)%/(14.21±8.08)%, AV-1(21.08±12.39)%/(18.09±7.38)%, AV(26.94±11.94)%/(25.52±8.64)%, AV+1(24.19±8.42)%/(20.82±8.69)%, AV+2(20.56±7.80)%/(15.60±9.71)%, total contribution(94.23±22.25)%, the disc wedging ratio/contribution ratio:AV-2D(2.88±2.57)%/(5.27±4.11)%, AV-1D(1.98±1.41)%/(2.29±2.16)%, AV+1D(-5.54±3.75)%/(-0.57±0.46)%, AV+2D(-8.27±4.62)%/(-1.22±1.11)%, total contribution (5.77±4.79)%. And the contribution rate of AV was significantly higher than that of adjacent vertebral(P<0.05).@*CONCLUSION@#The vertebral body and intervertebral disc shape both have influence on thoracolumbar kyphosis. However, the contribution of vertebral morphometry to the angle of TL/LDK deformity is relatively more important than the disc. The contribution of the wedge change of the AV to the TL/LDK deformity is particularly significant.

Preoperative standing to prone spinal-pelvic sagittal parameter changes in old traumatic spinal fractures with kyphosis / 中国修复重建外科杂志

OBJECTIVE@#To investigate the changes in spinal-pelvic sagittal parameters from preoperative standing to prone position in old traumatic spinal fractures with kyphosis.@*METHODS@#The clinical data of 36 patients admitted between December 2016 and June 2021 for surgical treatment of old traumatic spinal fractures with kyphosis, including 7 males and 29 females, aged from 50 to 79 years (mean, 63.9 years), were retrospectively analyzed. Lesion segments included 2 cases of T 11, 12 cases of T 12, 2 cases of T 11, 12, 4 cases of T 12 and L 1, 12 cases of L 1, 2 cases of L 2, 1 case of L 2, 3, and 1 case of L 3. The disease duration ranged from 4 to 120 months, with an average of 19.6 months. Surgical procedures included Smith-Petersen osteotomy in 4 cases, Ponte osteotomy in 6 cases, pedicle subtraction osteotomy in 2 cases, and improved fourth level osteotomy in 18 cases; the remaining 6 cases were not osteotomized. The bone mineral density ranged from -3.0 to 0.5 T, with a mean of -1.62 T. The spinal-pelvic sagittal parameters from preoperative standing to prone positions were measured, including local kyphosis Cobb angle (LKCA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and PI and LL mismatch (PI-LL). The kyphotic flexibility=(preoperative standing LKCA-preoperative prone LKCA)/preoperative standing LKCA×100%. Spinal-pelvic sagittal parameters were compared between standing position and prone position before operation, and Pearson correlation was used to judge the correlation between the parameters of standing position and prone position before operation.@*RESULTS@#When the position changed from standing to prone, LKCA and TK decreased significantly ( P<0.05), while SS, LL, PT, and PI-LL had no significant difference ( P>0.05). Pearson correlation analysis showed that LL was significantly correlated with SS and PI-LL in both standing and prone positions ( P<0.05), and the correlation strength between LL and SS in prone position was higher than that in standing position. In the standing position, LKCA was significantly correlated with SS and PT ( P<0.05). However, when the position changed from standing to prone, the correlation between LKCA and SS and PT disappeared, while PT and PI-LL was positive correlation ( P<0.05). The kyphotic flexibility was 25.13%-78.79%, with an average of 33.85%.@*CONCLUSION@#For the patients of old traumatic spinal fractures with kyphosis, the preoperative LKCA and TK decrease significantly from standing position to prone position, and the correlation between spinal and pelvic parameters also changed, which should be taken into account in the formulation of preoperative surgical plan.

Application of back-forward Bending CT localization image in the prediction of proximal junctional kyphosis after spinal deformity surgery in adults / 中国修复重建外科杂志

OBJECTIVE@#To investigate the feasibility of predicting proximal junctional kyphosis (PJK) in adults after spinal deformity surgery based on back-forward Bending CT localization images and related predictive indicators.@*METHODS@#A retrospective analysis was performed for 31 adult patients with spinal deformity who underwent posterior osteotomy and long-segment fusion fixation between March 2017 and March 2020. There were 5 males and 26 females with an average age of 62.5 years (range, 30-77 years). The upper instrumented vertebrae (UIV) located at T 5 in 1 case, T 6 in 1 case, T 9 in 13 cases, T 10 in 12 cases, and T 11 in 4 cases. The lowest instrumented vertebrae (LIV) located at L 1 in 3 cases, L 2 in 3 cases, L 3 in 10 cases, L 4 in 7 cases, L 5 in 5 cases, and S 1 in 3 cases. Based on the full-length lateral X-ray film of the spine in the standing position before and after operation and back-forward Bending CT localization images before operation, the sagittal sequence of the spine was obtained, and the relevant indexes were measured, including thoracic kyphosis (TK), lumbar lordosis (LL), local kyphosis Cobb angle (LKCA) [the difference between the different positions before operation (recovery value) was calculated], kyphosis flexibility, hyperextension sagittal vertical axis (hSVA), T 2-L 5 hyperextension C 7-vertebral sagittal offset (hC 7-VSO), and pre- and post-operative proximal junctional angle (PJA). At last follow-up, the patients were divided into PJK and non-PJK groups based on PJA to determine whether they had PJK. The gender, age, body mass index (BMI), number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, osteotomy grading, and related imaging indicators were compared between the two groups. The hC 7-VSO of the vertebral body with significant differences between groups was taken, and the receiver operating characteristic curve (ROC) was used to evaluate its accuracy in predicting the occurrence of PJK.@*RESULTS@#All 31 patients were followed up 13-52 months, with an average of 30.0 months. The patient's PJA was 1.4°-29.0° at last follow-up, with an average of 10.4°; PJK occurred in 8 cases (25.8%). There was no significant difference in gender, age, BMI, number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, and osteotomy grading between the two groups ( P>0.05). Imaging measurements showed that the LL recovery value and T 8-L 3 vertebral hC 7-VSO in the PJK group were significantly higher than those in the non-PJK group ( P>0.05). There was no significant difference in hyperextension TK, hyperextension LL, hyperextension LKCA, TK recovery value, LL recovery value, kyphosis flexibility, hSVA, and T 2-T 7, L 4, L 5 vertebral hC 7-VSO ( P>0.05). T 8-L 3 vertebral hC 7-VSO was analyzed for ROC curve, and combined with the area under curve and the comprehensive evaluation of sensitivity and specificity, the best predictive index was hC 7-L 2, the cut-off value was 2.54 cm, the sensitivity was 100%, and the specificity was 60.9%.@*CONCLUSION@#Preoperative back-forward Bending CT localization image can be used to predict the occurrence of PJK after posterior osteotomy and long-segment fusion fixation in adult spinal deformity. If the patient's T 8-L 2 vertebral hC 7-VSO is too large, it indicates a higher risk of postoperative PJK. The best predictive index is hC 7-L 2, and the cut-off value is 2.54 cm.

Back-forward bending CT in simulated surgical position to evaluate the remaining real angle and flexibility of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture / 中国修复重建外科杂志

OBJECTIVE@#To introduce a scout view scanning technique of back-forward bending CT (BFB-CT) in simulated surgical position for evaluating the remaining real angle and flexibility of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture.@*METHODS@#A total of 28 patients with thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture who met the selection criteria between June 2018 and December 2021 were included in the study. There were 6 males and 22 females with an average age of 69.5 years (range, 56-92 years). The injured vertebra were located at T 10-L 2, including 11 cases of single thoracic fracture, 11 cases of single lumbar fracture, and 6 cases of multiple thoracolumbar fractures. The disease duration ranged from 3 weeks to 36 months, with a median of 5 months. All patients received examinations of BFB-CT and standing lateral full-spine X-ray (SLFSX). The thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), local kyphosis of injured vertebra (LKIV), lumbar lordosis (LL), and the sagittal vertical axis (SVA) were measured. Referring to the calculation method of scoliosis flexibility, the kyphosis flexibility of thoracic, thoracolumbar, and injured vertebra were calculated respectively. The sagittal parameters measured by the two methods were compared, and the correlation of the parameters measured by the two methods was analyzed by Pearson correlation.@*RESULTS@#Except LL ( P>0.05), TK, TLK, LKIV, and SVA measured by BFB-CT were significantly lower than those measured by SLFSX ( P<0.05). The flexibilities of thoracic, thoracolumbar, and injured vertebra were 34.1%±18.8%, 36.2%±13.8%, and 39.3%±18.6%, respectively. Correlation analysis showed that the sagittal parameters measured by the two methods were positively correlated ( P<0.001), and the correlation coefficients of TK, TLK, LKIV, and SVA were 0.900, 0.730, 0.700, and 0.680, respectively.@*CONCLUSION@#Thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fracture shows an excellent flexibility and BFB-CT in simulated surgical position can obtain the remaining real angle which need to be corrected surgically.

Evaluation of cervical lordosis in patients with adolescent idiopathic scoliosis / Avaliação da lordose cervical nos pacientes com escoliose idiopática do adolescente / Evaluación de lordosis cervical en pacientes con escoliosis idiopática del adolescente

ABSTRACT: Introduction: In healthy individuals and in patients with adolescent idiopathic scoliosis (AIS), the curvature of the cervical spine varies greatly, with approximately 36-40% of AIS patients having kyphosis of the cervical spine. Aim: To assess the curvature of the cervical spine in AIS patients and subgroups according to Lenke's classification (1 to 6). Methods: 107 patients with AIS were assessed for cervical lordosis (C2-C7) using the Cobb method, subdivided into lordosis and cervical kyphosis. The following parameters were assessed and compared between the subgroups: T5-T12 thoracic kyphosis (TK); L1-S1 lumbar lordosis (LL), pelvic incidence (PI), sagittal vertical axis (SVA), T1 pelvic angle (TPA), C2-C7 cervical lordosis, C1-C2 cervical lordosis, T1 slope (T1s), neck tilt, thoracic inlet angle (TIA) and cervical sagittal axis (CSVA). Results: Kyphosis of the cervical spine was observed in 48% of patients. The Lenke classification curves (1 to 6) showed no difference with regard to the curvature of the cervical spine. In the subgroup with cervical lordosis, thoracic kyphosis, and T1 slope were significantly higher. Neck tilt was significantly higher in the subgroup with kyphosis. Conclusions: Almost half of the patients have kyphosis of the cervical spine, and the curvature of the cervical spine in AIS patients varies widely. Thoracic kyphosis, T1 slope, and neck tilt are significantly different between the subgroups of patients with lordosis or kyphosis. Level of Evidence III; Observational and Retrospective Study.

RESUMO: Introdução: Nos indivíduos saudáveis e nos pacientes com escoliose idiopática do adolescente (EIA) a curvatura da coluna cervical apresenta grande variação, sendo que aproximadamente 36-40% dos pacientes com EIA apresentam cifose da coluna cervical. Objetivo: Avaliar a curvatura da coluna cervical nos pacientes com EIA e nos subgrupos, de acordo com a classificação de Lenke (1 a 6). Métodos: Foram avaliados 107 pacientes com EIA quanto a lordose cervical (C2-C7), pelo método de Cobb, subdivididos em dois grupos: lordose e cifose cervical. Foram avaliados e comparados entre os subgrupos os seguintes parâmetros: cifose torácica T5-T12 (TK); lordose lombar L1-S1 (LL), incidência pélvica (PI), eixo sagital vertical (SVA), ângulo T1 pélvico (TPA), lordose cervical C2-C7, lordose cervical C1-C2, inclinação T1 (T1s), inclinação cervical (neck tilt), ângulo entrada torácica (TIA) e eixo cervical sagital (CSVA). Resultados: A cifose da coluna cervical foi observada em 48% dos pacientes. As curvas de classificação de Lenke (1 a 6) não apresentaram diferença com relação à curvatura da coluna cervical. No subgrupo com lordose cervical a cifose torácica e a inclinação de T1 foram significativamente maiores. A inclinação cervical foi significativamente maior no subgrupo com cifose. Conclusões: Quase a metade dos pacientes apresenta cifose da coluna cervical, sendo amplamente variável a curvatura da coluna cervical nos pacientes com EIA. A cifose torácica, a inclinação de T1 e a inclinação cervical são significativamente diferentes entre os subgrupos de pacientes com lordose ou cifose. Nível de Evidência III; Estudo Observacional e Retrospectivo.

RESUMEN: Introducción: En individuos sanos y en pacientes con escoliosis idiopática del adolescente (EIA), la curvatura de la columna cervical varía enormemente, y aproximadamente el 36-40% de los pacientes con EIA presentan cifosis de la columna cervical. Objetivo: Evaluar la curvatura de la columna cervical en pacientes con EIA y subgrupos según la clasificación de Lenke (1 a 6). Métodos: Se evaluó la lordosis cervical (C2-C7) de 107 pacientes con EIA mediante el método de Cobb, subdivididos en dos grupos: lordosis y cifosis cervical. Se evaluaron y compararon los siguientes parámetros entre los subgrupos: Cifosis torácica (TK) T5-T12; lordosis lumbar (LL) L1-S1, incidencia pélvica (PI), eje vertical sagital (SVA), ángulo pélvico T1 (TPA), lordosis cervical C2-C7, lordosis cervical C1-C2, inclinación T1 (T1s), inclinación del cuello, ángulo de la entrada torácica (TIA) y eje sagital cervical (CSVA). Resultados: Se observó cifosis de la columna cervical en el 48% de los pacientes. Las curvas de clasificación de Lenke (1 a 6) no mostraron diferencias con respecto a la curvatura de la columna cervical. En el subgrupo con lordosis cervical, la cifosis torácica y la inclinación T1 eran significativamente mayores. La inclinación cervical fue significativamente mayor en el subgrupo con cifosis. Conclusiones: Casi la mitad de los pacientes presentan cifosis de la columna cervical, y la curvatura de la columna cervical en los pacientes con EIA varía ampliamente. La cifosis torácica, la inclinación T1 y la inclinación cervical son significativamente diferentes entre los subgrupos de pacientes con lordosis o cifosis. Nivel de Evidencia: III; Estudio Observacional y Retrospectivo.

Changes in sagittal balance in thoracolumbar posttraumatic kyphosis surgery / Alterações no equilíbrio sagital na cirurgia de cifose pós-traumática toracolombar / Cambios en el equilibrio sagital en la cirugía de cifosis postraumática toracolumbar

ABSTRACT: Objective: The analysis of the X-ray results of surgical treatment performed in patients with post-traumatic thoracolumbar kyphosis and identification of the compensatory mechanism for this deformity. Methods: The data of 140 patients surgically treated for painful post-traumatic kyphosis at the level of T12, L1, and L2 vertebrae was analyzed. Results: In the studied group, the initial kyphotic deformity was 23° to 81°, with a mean of 28.1°. All patients underwent staged surgical intervention in a single surgical session. Post-traumatic kyphosis (LK) was completely corrected, on average, to -0.25°. After kyphosis correction, increased thoracic kyphosis (TK) decreased lumbar lordosis (LL), including at the expense of low lumbar lordosis (LowLL), but no changes in pelvic balance parameters were observed. Statistically significant correlations of local kyphosis correction magnitude of 28.36±8.89°, with magnitudes of lumbar lordosis (LL), thoracic kyphosis (TK), low lumbar lordosis (LowLL) were obtained. The global sagittal and pelvic balance demonstrated no correlations with the magnitude of kyphosis correction. The X-ray parameters were studied in patients of Group I with no signs of initial sagittal imbalance and in Group II patients with signs of sagittal imbalance. The groups demonstrated statistically significant differences in global balance parameters and spinopelvic parameters both before and after correction surgery. Conclusion: The study revealed that the basic compensatory mechanism for post-traumatic thoracolumbar kyphosis is implemented by changes in the curves adjacent to kyphosis - a decrease in thoracic kyphosis and an increase in lumbar lordosis but not by changes in global or spinopelvic balance. Level of Evidence - III; A case-control study.

RESUMO: Objetivo: Análise dos resultados radiográficos do tratamento cirúrgico realizado em pacientes com cifose toracolombar pós-traumática e identificação do mecanismo compensatório dessa deformidade. Métodos: Foram analisados os dados de 140 pacientes tratados cirurgicamente por cifose pós-traumática dolorosa ao nível das vértebras T12, L1, L2. Resultados: No grupo estudado a deformidade cifótica inicial foi de 23° a 81°, média de 28,1°. Todos os pacientes foram submetidos à intervenção cirúrgica estadiada em uma única sessão cirúrgica. A cifose pós-traumática (LK) foi completamente corrigida, em média para -0,25°. Após a correção da cifose foi revelado aumento da cifose torácica (TK), diminuição da lordose lombar (LL), inclusive em detrimento da baixa lordose lombar (LowLL), mas não foram observadas alterações nos parâmetros de equilíbrio pélvico. Foram obtidas correlações estatisticamente significativas da magnitude de correção da cifose local de 28,36±8,89°, com magnitudes de lordose lombar (LL), cifose torácica (TK), lordose lombar baixa (LowLL). O equilíbrio sagital global e o equilíbrio pélvico não demonstraram correlações com a magnitude da correção da cifose. Os parâmetros radiográficos foram estudados nos pacientes do Grupo I sem sinais de desequilíbrio sagital inicial e naqueles do Grupo II com sinais de desequilíbrio sagital. Os grupos demonstraram diferenças estatisticamente significativas nos parâmetros de equilíbrio global e nos parâmetros espinopélvicos antes e após a cirurgia de correção. Conclusão: O estudo revelou que o mecanismo compensatório básico da cifose toracolombar pós-traumática é implementado por alterações nas curvas adjacentes à cifose - diminuição da cifose torácica e aumento da lordose lombar, mas não por alterações no equilíbrio global ou espinopélvico. Nível de Evidência III; Estudo caso controle.

RESUMEN: Objetivo: Análisis de los resultados radiológicos del tratamiento quirúrgico realizado a pacientes con cifosis toracolumbar postraumática e identificación del mecanismo compensador de esta deformidad. Métodos: Se analizaron los datos de 140 pacientes tratados quirúrgicamente por cifosis postraumática dolorosa a nivel de las vértebras T12, L1, L2. Resultados: En el grupo estudiado, la deformidad cifótica inicial osciló entre 23° y 81°, con un promedio de 28,1°. Todos los pacientes fueron sometidos a una intervención quirúrgica escalonada en una única sesión quirúrgica. La cifosis postraumática (LK) se corrigió completamente, en promedio a -0,25°. Después de la corrección de la cifosis, se reveló un aumento de la cifosis torácica (TK) y una disminución de la lordosis lumbar (LL), incluso a expensas de una lordosis lumbar baja (LowLL), pero no se observaron cambios en los parámetros del equilibrio pélvico. Se obtuvieron correlaciones estadísticamente significativas entre la magnitud de corrección de la cifosis local de 28,36±8,89°, con las magnitudes de lordosis lumbar (LL), cifosis torácica (TK), lordosis lumbar baja (LowLL). El equilibrio sagital global y el equilibrio pélvico no demostraron correlaciones con la magnitud de la corrección de la cifosis. Los parámetros radiológicos se estudiaron en pacientes del Grupo I sin signos de desequilibrio sagital inicial y en aquellos del Grupo II con signos de desequilibrio sagital. Los grupos demostraron diferencias estadísticamente significativas en los parámetros del equilibrio global y los parámetros espinopélvicos antes y después de la cirugía correctora. Conclusión: El estudio reveló que el mecanismo compensatorio básico de la cifosis toracolumbar postraumática se implementa mediante cambios en las curvas adyacentes a la cifosis (disminución de la cifosis torácica y aumento de la lordosis lumbar), pero no mediante cambios en el equilibrio global o espinopélvico. Nivel de Evidencia III; Estudio de casos y controles.

Sagittal misalignment in adolescent idiopathic scoliosis / Desalinhamento sagital na escoliose idiopática do adolescente / Mala alineación sagital en la escoliosis idiopática del adolescente

ABSTRACT: Introduction: The correlation between sagittal and coronal parameters in patients with adolescent idiopathic scoliosis (AIS) presents contradictory results and is not fully understood. Objective: To evaluate the sagittal vertical axis (SVA) and its correlation with sagittal parameters and the main curve in patients diagnosed with AIS. Methods: 109 patients with AIS and indications for surgical treatment were evaluated. The correlation of the SVA with sagittal parameters (thoracic kyphosis, lumbar lordosis, pelvic incidence, lumbar lordosis, pelvic version, and sacral inclination) and with the main curves (main thoracic and thoracolumbar/lumbar) was evaluated. Results: The SVA ranged from -208 to 66.30 mm (mean -19.64 ± 36.21), above 50 mm in two patients (1.83%). There was no correlation between the sagittal parameters and the magnitude of the main curve and the SVA. Conclusion: The SVA showed great variability in the group of patients with AIS; a small percentage of patients had an SVA greater than 50 mm. The low percentage of patients with sagittal misalignment showed the compensatory capacity of young patients with vertebral deformity. Level of Evidence: III; Observational and Retrospective Study.

RESUMO: Introdução: A correlação entre os parâmetros sagitais e coronais nos pacientes com escoliose idiopática do adolescente (EIA) apresenta resultados contraditórios e não está totalmente esclarecida. Objetivo: Avaliar o eixo sagital vertical (SVA) e sua correlação com parâmetros sagitais e a curva principal de pacientes com diagnóstico de EIA. Métodos: Foram avaliados 109 pacientes com EIA e indicação de tratamento cirúrgico. Foi avaliada a correlação do SVA com parâmetros sagitais (cifose torácica, lordose lombar, incidência pélvica, lordose lombar, versão pélvica e inclinação do sacro) e com as curvas principais (torácica principal e toracolombar/lombar). Resultados: O SVA variou de -208 a 66,30 mm (média -19,64 ± 36,21), ficando acima de 50 mm em dois pacientes (1,83%). Não foi observada correlação dos parâmetros sagitais e da magnitude da curva principal com o SVA. Conclusão: O SVA apresentou grande variabilidade no grupo de pacientes com EIA e pequena porcentagem dos pacientes apresentaram SVA maior que 50 mm. A baixa porcentagem de pacientes com desalinhamento sagital evidenciou a capacidade compensatória dos pacientes jovens e com deformidade vertebral. Nível de Evidência: III; Estudo Observacional e Retrospectivo.

RESUMEN: Introducción: La correlación entre los parámetros sagitales y coronales en pacientes con escoliosis idiopática del adolescente (EIA) presenta resultados contradictorios y no se comprende completamente. Objetivo: Evaluar el eje vertical sagital (SVA) y su correlación con los parámetros sagitales y la curva principal en pacientes diagnosticados de EIA. Métodos: Se evaluaron 109 pacientes con EIA e indicación de tratamiento quirúrgico. Se evaluó la correlación del SVA con parámetros sagitales (cifosis torácica, lordosis lumbar, incidencia pélvica, lordosis lumbar, versión pélvica e inclinación sacra) y con las curvas principales (torácica principal y toracolumbar/lumbar). Resultados: El SVA osciló entre -208 y 66,30 mm (media -19,64 ± 36,21), siendo superior a 50 mm en dos pacientes (1,83%). No hubo correlación entre los parámetros sagitales o la magnitud de la curva principal y el SVA. Conclusión: El SVA mostró una gran variabilidad en el grupo de pacientes con EIA y un pequeño porcentaje de pacientes presentó una SVA superior a 50 mm. El bajo porcentaje de pacientes con desalineación sagital mostró la capacidad compensatoria de los pacientes jóvenes con deformidad vertebral. Nivel de Evidencia: III; Estudio Observacional y Retrospectivo.

Evaluation of kyphosis measurement in thoracolumbar spine fractures / Avaliação da mensuração da cifose nas fraturas da coluna toracolombar / Evaluación de la medición de cifosis en fracturas de la columna toracolumbar

ABSTRACT Objectives: Evaluate the reliability and reproducibility of the kyphosis measurement in thoracolumbar spine traumatic fractures by different assessment methods in different types of fractures. Methods: Fifteen fractures of the thoracolumbar spine, previously classified into types A, B, and C according to Magerl's classification, were evaluated. The value of kyphosis was measured using five different methods: (1) Cobb angle; (2) Gardner's method; (3) back wall method; (4) angle of adjacent endplates; and (5) wedge angle. The measurements were performed by five independent observers and repeated five times with a minimum interval of two weeks between each evaluation. Results: Intraobserver reliability was excellent among the five observers, evidencing good reproducibility of the methods. The five methods used also showed great intraobserver reliability in the global analysis, with methods one and four being more consistent. Conclusion: Although there is no universal agreement on measuring kyphosis in thoracolumbar fractures, our study concluded that method 1 (Cobb angle) and method 4 (adjacent endplate angle) presented the best interobserver reliabilities. Furthermore, the use of digitized radiographs and a simple computer program allowed the performance of highly reliable and reproducible measurements by all methods, given the high intraobserver reliability. Level of Evidence II; Comparative study.

Resumo: Objetivos: Avaliar a confiabilidade e reprodutibilidade da mensuração da cifose nas fraturas traumáticas da coluna toracolombar por diferentes métodos de avaliação nos diferentes tipos de fraturas. Métodos: Foram avaliadas 15 fraturas na coluna toracolombar previamente classificadas em tipo A, B e C de acordo com a classificação de Magerl. Em cada caso, foi medido o valor da cifose através de cinco diferentes métodos: (1) ângulo de Cobb; (2) método de Gardner; (3) método das paredes posteriores; (4) ângulo das placas terminais adjacentes; e (5) ângulo de cunha. As mensurações foram realizadas por cinco avaliadores independentes e repetidas cinco vezes com intervalo mínimo de duas semanas entre cada avaliação. Resultados: A confiabilidade intraobservador mostrou-se excelente entre os cinco avaliadores, evidenciando boa reprodutibilidade dos métodos. Os cinco métodos utilizados também apresentaram grande confiabilidade intraobservador na análise global, sendo mais consistentes o método 1 e o método 4. Conclusão: Apesar de não haver concordância universal em como medir a cifose nas fraturas toracolombares, nosso estudo concluiu que o método 1 (ângulo de Cobb) e o método 4 (ângulo das placas terminais adjacentes) apresentaram as melhores confiabilidades interobservadores. Além disso, o uso de radiografias digitalizadas e um programa computadorizado simples permitiram a realização de medidas altamente confiáveis e reprodutíveis por todos os métodos, visto pela elevada confiabilidade intraobservador. Nível de evidência II; Estudo Comparativo.

Resumen: Objetivos: Evaluar la fiabilidad y reproducibilidad de mensuración de cifosis en fracturas traumáticas de la columna toracolumbar por diferentes métodos de valoración en diferentes tipos de fracturas. Métodos: Se evaluaron quince fracturas de columna toracolumbar, previamente clasificadas en los tipos A, B y C según la clasificación de Magerl. En cada caso, el valor de la cifosis se midió utilizando cinco métodos diferentes: (1) ángulo de Cobb; (2) método de Gardner; (3) método de la pared posterior; (4) ángulo de placas de extremo adyacentes; y (5) ángulo de cuña. Las mediciones fueron realizadas por cinco evaluadores independientes y repetidas cinco veces con un intervalo mínimo de dos semanas entre cada evaluación. Resultados: La confiabilidad intraobservador fue excelente entre los cinco evaluadores, evidenciando una buena reproducibilidad de los métodos. Los cinco métodos utilizados también mostraron una gran fiabilidad intraobservador en el análisis global, siendo el método 1 y el método 4 más consistentes. Conclusión: Aunque no existe un acuerdo universal sobre cómo medir la cifosis en las fracturas toracolumbares, nuestro estudio concluyó que el método 1 (ángulo de Cobb) y el método 4 (ángulo de la placa terminal adyacente) presentaron las mejores confiabilidades entre observadores. Además, el uso de radiografías digitalizadas y un programa informático simple permitieron realizar mediciones altamente fiables y reproducibles por todos los métodos, dada la alta fiabilidad intraobservador. Nivel de evidencia II; Estudio Comparativo.

Radiographic evaluation of surgical correction of scoliosis due to cerebral palsy using intra-operative traction and new correction technique with 3rd provisional rod / Avaliação radiográfica de correção cirúrgica de escoliose devido a paralisia cerebral usando tração intraoperativa e nova técnica de correção com terceira haste provisória / Evaluación radiográfica de corrección quirúrgica de escoliosis debido a paralisia cerebral mediante tracción intraoperativa y nueva técnica de corrección con tercera barra provisoria

ABSTRACT Objective: Evaluate the radiographic results of patients with cerebral palsy and Lonstein and Akbarnia type II scoliosis who underwent intraoperative halofemoral traction (IFAT) and correction with a 3rd provisional nail. Methods: Retrospective case series study. Were evaluated preoperative (PRE), traction (TR), immediate (POI), and late (POT) total spine radiographs. Were verified the angular value of the main curve (COBB), pelvic obliquity (OP), trunk balance in the coronal plane (CSVA), vertical sagittal alignment (SVA), curve flexibility, and percentage of correction in the final PO. Friedam and Wilcoxon tests were performed (p<0.05). Results: Twenty-one patients were included in the study, with a mean age of 16 (±4.13). There was a statistical difference when comparing COBB PRE with TRACTION to POI and POT (p=0.0001), OP in PRE with TRACTION, and between PRE and POT (p=0.0001). There was a statistical difference in coronal (CSVA) and sagittal (SVA) balance concerning PRE and POT. The percentage of correction for the main curve was 55.75% (± 11.11), and for the O P, 64.86% (± 18.04). Conclusion: The correction technique using the 3rd provisional nail technique and intraoperative traction presents a correction power of 55.75% of the proximal curve and 64% of the pelvic obliquity. In addition, it is easy to assemble, has a short surgical time, and causes little loss of correction during follow-up. Level of Evidence III B; I study a series of retrospective cases.

Resumo: Objetivo: Avaliar os resultados radiográficos de pacientes com paralisia cerebral e escoliose tipo II de Lonstein e Akbarnia submetidos à tração halo-femoral intra-operatória (THFI) e correção com 3ª haste provisória. Métodos: Estudo série de casos retrospectivo. Foram avaliadas radiografias de coluna total pré-operatórias (PRÉ), sob tração (TR), pós-operatória imediata (POI) e tardia (POT). Verificou-se valor angular da curva principal (COBB), obliquidade pélvica (OP), equilíbrio do tronco no plano coronal (CSVA), alinhamento sagital vertical (SVA), flexibilidade da curva e percentual de correção no PO final. Foram realizados os testes de Friedam e Wilcoxon (p<0,05). Resultados: Vinte e um pacientes foram incluídos no estudo, com idade média de 16 (±4,13) anos. Houve diferença estatística quando se comparou: COBB PRÉ com TRAÇÃO em relação ao POI e POT (p=0,0001), OP no PRÉ com TRAÇÃO e entre o PRÉ e POT (p=0,0001). Houve diferença estatística em relação ao equilíbrio coronal (CSVA) e sagital (SVA) em relação ao PRE e POT. O percentual de correção da curva principal foi de 55,75% (± 11,11) e da OP de 64,86% (± 18,04). Conclusão: A técnica de correção utilizando a técnica da 3° haste provisória e tração intra-operatória apresenta poder de correção de 55,75% da curva proximal e 64% da obliquidade pélvica. Além disso, apresenta facilidade de montagem, tempo cirúrgico pequeno e pouca perda de correção ao longo do seguimento. Nível de Evidência III B; Estudo de série de casos retrospectivos.

Resumen: Objetivo: Evaluar los resultados radiográficos de pacientes con parálisis cerebral y escoliosis tipo II de Lonstein y Akbarnia a quienes se les realizó tracción halofemoral intraoperatoria (THFI) y corrección con una tercera barra provisoria. Métodos: Estudio retrospectivo de serie de casos. Se evaluaron radiografías totales de columna preoperatorias (PRE), de tracción (TR), post-operatorias inmediatas (POI) y tardías (POT). Se verificó el valor angular de la curva principal (COBB), la oblicuidad pélvica (OP), el equilibrio del tronco en el plano coronal (CSVA), la alineación sagital vertical (SVA), la flexibilidad de la curva y el porcentaje de corrección en el PO final. Se realizaron las pruebas de Friedam y Wilcoxon (p<0,05). Resultados: Se incluyeron en el estudio 21 pacientes, con una edad media de 16 (±4,13) años. Hubo diferencia estadística al comparar: COBB PRE con TRACCIÓN en relación a POI y POT (p=0,0001), OP en PRE con TRACCIÓN y entre PRE y POT (p=0,0001). Hubo diferencia estadística en relación al equilibrio coronal (CSVA) y sagital (SVA) en relación a PRE y POT. El porcentaje de corrección para la curva principal fue del 55,75% (± 11,11) y para la OP del 64,86% (± 18,04). Conclusión: La técnica de corrección mediante la técnica de la tercera barra provisoria y tracción intraoperatoria presenta un poder de corrección del 55,75% de la curva proximal y del 64% de la oblicuidad pélvica. Además, es de fácil montaje, tiene un tiempo quirúrgico corto y poca pérdida de corrección durante el seguimiento. Nivel de evidencia III B; Estudio una serie de casos retrospectivos.

Spinal Stenosis and Thoracolumbar Kyphosis in Achondroplasia / 罕见病研究

Achondroplasia (ACH) is a rare autosomal-dominant genetic disease resulting from a mutation in the fibroblast growth factor receptor-3 (FGFR3) gene. It is characterized by asymmetric short stature. Spinal stenosis and thoracolumbar kyphosis (TLK) are common findings in ACH patients. Severe TLK can exacerbate spinal stenosis, leading to neurological complications. This paper provides a brief review of the pathophysiological mechanisms, clinical characteristics, and treatments for spinal stenosis and TLK in ACH patients. Recently, three new drugs targeting FGFR3; vosoritide, recifercept, and infigratinib, have completed or are undergoing clinical trials. They have shown promising preliminary results in preventing spinal stenosis and TLK.

Clinical outcomes of selecting the vertebra above sagittal stable vertebra as distal fusion level for Scheuermann's thoracic kyphosis / 中华骨科杂志

Objective:To investigate the clinical outcome and complications associated with utilizing sagittal plane stable vertebra-1 (SSV-1) as the distal instrumented vertebra (LIV) in posterior fusion of thoracic kyphosis with Scheuermann's Disease kyphosis (STK).Methods:A longitudinal study on patients with STK who underwent posterior correction and fusion surgery from January 2018 to June 2021 were conducted. All participants had a follow-up duration over two years. Patients were divided into two groups according to the segment of LIV: the SSV group, where LIV was located in SSV; and the SSV-1 group, where LIV was located in the vertebral body above SSV. The radiographic parameters, including global kyphosis (GK), lumbar lordosis (LL), and sagittal plane (SVA), LIV offset distance (LIV translation), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS), were compared between the two groups. The SRS-22 scale was used to evaluate health-related quality of life at pre-operation and last follow-up, and the incidence of postoperative distal junctional kyphosis (DJK) was also recorded. Analytical techniques, such as Analysis of Variance and Mann-Whitney tests, were employed to compare inter-group differences.Results:A total of 57 patients were included in the study, 36 in the SSV group and 21 in the SSV-1 group. The average age for patients were 16.1±2.3 years (range 13-20 years), and the average follow-up time was 32.8±6.8 months (range 24-53 months). There were no statistically significant differences between the two groups in terms of gender, age, follow-up time, surgical time, intraoperative bleeding volume, and fusion level. Before surgery, the LIV deviation distance in the SSV group was significantly lower than that in the SSV-1 group (-7.9±11.0 mm vs. 31.5±11.5 mm, t=7.64, P<0.001). In the SSV group, the preoperative GK was 79.3°±10.5°, and the last follow-up GK was 44.4°±8.5°, which was significantly improved compared to preoperative value ( t=28.28, P<0.001); in the SSV-1 group, the preoperative GK was 81.1°±10.6°, and the value at 1-week post-operative was 44.9°±7.8°, which was significantly improved compared to pre-operative value ( t=22.23, P<0.001). At the last follow-up, it was 45.1°±8.7°, with a correction rate of 44.3%±8.5%. No significant difference was observed between the two groups in terms of GK, LL, SVA, PI, PT and SS at pre-operative, 1-week post-operative and last follow-up ( P>0.05). All patients had no intraoperative complications of nerve injury. During the follow-up period, one patient (1/21, 4.8%) developed DJK without complications such as proximal kyphosis, pseudarthrosis, or failed internal fixation. At the last follow-up, the functional score of SRS-22 in SSV-1 group improved from preoperative (3.5±0.54) to postoperative (4.1±0.62), with an average improvement rate of 19.2%±3.2%, and the difference was statistically significant ( t=3.74, P=0.001). These results indicating that the surgical treatment was effective in relieving the symptoms of the patients. Conclusion:Selecting SSV-1 as LIV in corrective surgeries for STK appears to produce commendable clinical results with minimal implant-associated complications over a two-year observation period.

The utilization of second sacral alar-iliac screw fixation technique in the treatment of adult spinal deformity: analysis of risk factors for postoperative sagittal imbalance / 中华骨科杂志

Objective:To evaluate the clinical outcomes and complications of second sacral alar-iliac (S 2AI) technique utilized in degenerative spinal deformity patients, and to analyze the potential risk factors for postoperative sagittal imbalance. Methods:From January 2014 to October 2020, a consecutive cohort of 39 degenerative spinal deformity patients who were treated with S 2AI were retrospectively reviewed, including 4 males and 35 females, aged 63.1±6.7 years (range, 43-73 years). All of the patients had a minimum of 2-year follow-up. According to the sagittal vertical axis (SVA) at the final follow-up, patients were divided into 2 groups. Sagittal balance group (SVA≤50 mm) and sagittal imbalance group (SVA>50 mm). Radiographic parameters including the Cobb's angle, coronal balance distance (CBD), thoracic kyphosis (TK), lumbar lordosis (LL), SVA, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) were measured in the standing radiographs before and after operation and at the latest follow up. Comparison was made between the two groups and the differences with statistical significance were analyzed with binary logistic regression analysis. Intraoperative and postoperative complications were recorded. The Scoliosis Research Society-22 (SRS-22) score were employed to evaluate the quality of life. Results:The average follow-up period was 30.3±9.1 months (range, 43-73 months). Eighteen patients (46%) were identified with sagittal imbalance at the last follow-up. Compared with the patients in the sagittal balance group, the preoperative SVA was significantly larger (83.1±56.2 mm vs. 48.1±51.1 mm, t=2.04, P=0.049) and the postoperative TK was significantly greater (27.8°±9.6° vs. 18.9°±13.4°, t=2.36, P=0.024) for patients in the sagittal imbalance group. Scores of pain domain (3.2±0.5 vs. 3.7±0.6) and self-image domain (3.4±0.8 vs. 3.8±0.6) in sagittal imbalance group were significantly lower than those of sagittal balance group ( P<0.05). Logistic regression analysis showed that larger preoperative SVA ( OR=1.02, P=0.028) and greater postoperative TK ( OR=1.09, P=0.022) were independent risk factors for the occurrence of sagittal imbalance during the follow-up periods. Conclusion:S 2AI screw fixation can achieve satisfying coronal deformity correction and great sagittal reconstruction after surgery in patients with degenerative spinal deformity. However, sagittal imbalance may still occur during the follow-up periods. Larger preoperative SVA and greater postoperative TK are independent risk factors for the occurrence of sagittal imbalance.

Association between cervical curve and the cranio-cervical curve and ossification of ligaments in patients with cervical degenerative diseases / 中华骨科杂志

Objective:To explore the correlation between cervical curve and ossification of ligaments in cranio-cervical junction and cervical spine in patients with cervical degenerative diseases.Methods:A retrospective study was conducted among 458 patients with cervical degenerative disease who underwent cervical spine X-ray and CT examinations at the Orthopedics Department of Beijing Tiantan Hospital, Capital Medical University between January 2016 and July 2020. There were 265 males and 193 females, with an average age of 57.02±10.41 years (range, 22-87 years). Patients were divided into 5 types (lordosis, straight, S-type degenerative kyphosis, R-type degenerative kyphosis and C-type degenerative kyphosis). Cervical lordosis was defined as C 2-C 7 curve <-4°, cervical kyphosis was defined as >4°, cervical straight was defined as -4° to 4°. C 2-C 7 curve, C 0-C 2 curve were measured respectively, and correlations among these imaging parameters were analyzed. CT images were used to assess the presence of ossification of ligaments in cranio-cervical and cervical spine, including ossification of the posterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, apical ligament, diffuse idiopathic skeletal hyperostosis (DISH), as well as capped dens sign (CDS), and correlations between these cervical curve and presence of ossification of ligaments were analyzed. The different grades were based on the length of the ossification of interest with respect to the distance from the posterosuperior rim of the anterior arch of the atlas to the inferior margin of the foramen magnum on mid-sagittal cervical spine CT images, Grade 3 CDS was determined when the length was more than two-thirds. Results:There were 245 patients with cervical lordosis, 114 patients with straight, 53 patients with S-type degenerative cervical kyphosis, 36 patients with R-type degenerative cervical kyphosis and 10 patients with C-type degenerative cervical kyphosis. C 0-C 2 curve showed a negative correlation with C 2-C 7 curve in all enrolled patients ( r=-0.45, P<0.001) and R-type degenerative kyphosis group ( r=-0.58, P<0.001); C 0-C 2 curve showed no correlation with C 2-C 7 curve in lordosis ( r=-0.10, P=0.124), straight ( r=-0.11, P=0.233), S-type degenerative kyphosis ( r=-0.01, P=0.943) or C-type degenerative kyphosis groups ( r=0.03, P=0.946). CDS was detected in 38.4% (176/458) of patients, and Grade 3 was detected in 17.9% (82/458) of patients. The prevalence of CDS was correlated with R-type degenerative cervical kyphosis ( r=0.10, P=0.030). Cervical kyphosis, S-type degenerative kyphosis, C-type degenerative kyphosis, C 2-C 7 curve and C 0-C 2 curve showed no correlation with ossification of the posterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, apical ligament, diffuse idiopathic skeletal hyperostosis (DISH) or different grades CDS ( P>0.05). Conclusion:R-type degenerative cervical kyphosis are more likely to correlate with the cranio-cervical curve and CDS, which is an ossification of ligament in cranio-cervical junction.

Graded surgical strategy for osteoporotic vertebral compression fractures with kyphosis: application of balanced load concept / 中华骨科杂志

Objective:To explore the application value of graded surgical strategy and balanced load concept for thoracolumbar osteoporotic compression fractures (OVCFs) with kyphosis.Methods:All of 56 patients of thoracolumbar OVCFs with kyphosis were studied, including 11 males and 45 females, with an average of 75.6±9.3 years old. All patients had back pain, and 32 patients had nerve compression, including 5 patients with aggravation of vertebral collapse after conservative treatment, and 1 patient with cement loosening after percutaneous kyphoplasty (PKP) in another hospital. A graded surgical strategy was developed according to the concept of balanced load, including whether there existed nerve compression, kyphosis, sagittal index (SI), vertebral collapse, load capacity of anterior and middle columns, and fracture reducibility. All patients were treated with anti osteoporosis therapy. 24 patients without nerve compression underwent posture reduction and PKP; 32 patients with nerve compression underwent open surgery: 5 patients with arcuate ky-phosis and SI≤15° underwent Ponte osteotomy; 15 patients with angular kyphosis or SI>15° underwent posterior pedicle subtraction osteotomy (PSO) or/and modified PSO including intervertebral space; 11 patients with SI>15° and severe vertebral collapse (the height of anterior and middle vertebral bodies <1/3 of the average height of adjacent vertebral bodies) or cement loosen after PKP underwent vertebrectomy and reconstruction, of which 4 patients underwent posterior vertebral column resection (PVCR), and 8 patients underwent combined surgery including anterior subtotal vertebrectomy with support and posterior pedicle fixation. The clinical efficacy was evaluated by pain visual analog score (VAS) and Oswestry dysfunction index (ODI).Results:All patients were followed up for 12-60 months, with an average of 24.2 months. For the 24 patients with PKP, the symptoms improved significantly, and 1 case had adjacent vertebral fracture that was improved after PKP again. For the 32 patients with open surgery, the intraoperative blood loss was 400-1 800 ml, with an average of 960 ml (PVCR > PSO and combined surgery > Ponte); the operation time was 2-7 h, with an average of 4.3±1.9 h. The neurological symptoms improved after the operation. During follow-up, the artificial vertebral body and titanium mesh collapsed in 3 cases, but did not continue to deteriorate, no vertebral fracture, internal fixation displacement or loosening failure occurred on X-ray films. At the last follow-up, the VAS score and ODI score of 56 patients decreased from 7.0±2.6 and 60.4±16.2 pre-operation to 1.4±1.1 and 9.5+5.8 respectively, and local kyphosis angle improved from 18.1±4.3 pre-operation to 5.6±4.3. According to the overall satisfaction of patients, the effect was fair in 12 cases, good in 30 cases, excellent in 14 cases, and the excellent and good rate was 78.6%.Conclusion:The graded surgical strategy for thoracolumbar OVCFs with kyphosis based on the concept of balanced load can restore the balanced load of the anterior and middle columns of the spine, reduce the fixation and fusion segments, and reduce the risk of internal fixation displacement and loosening failure.

Progress in open surgical treatment of thoracolumbar kyphosis secondary to old osteoporotic vertebral compression fractures / 中华骨科杂志

Osteoporotic vertebral compression fracture (OVCF) is the most common complication of spinal osteoporosis, mostly occurring in thoracolumbar segment, which can cause acute and chronic pain at the fracture site and loss of vertebral height, and can lead to progressive kyphosis. For kyphosis caused by old OVCF, open surgery such as anterior or posterior decompression and fusion, internal fixation and osteotomy can improve local sequence and achieve satisfactory kyphotic correction which is difficult to complete in percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP), and reconstruct the sagittal balance. Due to the older age of OVCF patients, some of them have poor general conditions. In addition, osteoporosis leads to increased vertebral fragility, which increases the risk of surgery and postoperative internal fixation failure. The anterior approach presents some problems including a complex approach and poor mechanical stability. At present, most studies focus on posterior surgery. Due to the limitation of kyphosis correction by decompression and fixation alone, osteotomy is often required to correct kyphosis. In cases of old OVCF with kyphosis, the screw holding capability decreases due to the decrease of bone mineral density. Additionally, once the screw loosens, the orthopedic effect is inevitably affected. To enhance pedicle screws, most studies have utilized bone cement to increase the axial pullout force of the vertebral body and improve screw stability. The selection from different osteotomy methods is a critical determinant in achieving favorable surgical outcomes for patients.

An analysis on the optimal match between thoracolumbar kyphosis and lower lumbar lordosis in adult spinal deformity after long-fusion surgery / 中华骨科杂志

Objective:To explore the optimal match degree between thoracolumbar kyphosis (TLK) and lower lumbar lordosis (LLL) in adult spinal deformity (ASD) after correction surgery.Methods:Data of 119 ASD patients (male: 28, female: 91), belonging to the Affiliated Hospital of Jining Medical University (19 cases), the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (11 cases), and the First Medical Center of Chinese PLA General Hospital (89 cases) were reviewed and documented from March 2019 to March 2020. All patients (age, 64.48±8.88 years; range, 45-79 years) underwent the surgical procedure of thoracolumbar fusion with instrumentations were followed up over 24 months (51.68±15.60 months; range, 24-87 months) after surgery. Postoperative proximal interface failure, Oswestry disability index (ODI) score and Scoliosis Research Society-22 (SRS-22) score were recorded for all patients. The immediate match of TLK to LLL postoperatively was calculated as follows: TLM=TLK/LLL. The data of those individuals with excellent improvements in the ODI (>50%) at the final follow-up were recorded and analyzed. Then the mean value and the 95% CI of TLM in those individuals were calculated. All participants were subdivided into three groups according to the 95% CI value of TLM. After the receiver operating characteristic curve (ROC) analyzing, the area under the ROC curve (AUC) was the best cutoff value of TLM. The association of proximal junctional failure (PJF) developing with the abnormal TLM postoperatively was analyzed with logistic regression, and the odds ratio (OR) was calculated. Results:62 patients had significant improvements in ODI (>50%) at the final follow-up, and the mean TLM in those individuals was 0.41 [95% CI (0.2, 0.5)]. All patients were divided into three groups: TLM<0.2 (35 cases), 0.2≤TLM≤0.5 (48 cases) and TLM>0.5 (36 cases). The preoperative TLK (13.87°±16.61°) and T 1 pelvic angle (19.69°±10.55°) in the those patients with TLM<0.2 were the smallest, and those were the largest in those with TLM>0.5 (30.59°±16.68°, 28.30°±14.46°). The individuals with TLM<0.2 still had the smallest TLK (2.89°±1.78°), however, those with TLM>0.5 had the largest TLK (17.13°±12.13°) and the smallest LLL (-26.16°±11.02°) accordingly. Additionally, the ODI and SRS-22 for those with 0.2≤TLM≤0.5 at the final follow-up were the best ( P<0.05). ROC curve analysis results showed that the best cutoff value of TLM was 0.4 (sensitivity=78.9%, specificity=76.2%; AUC=0.802, 95% CI (0.708, 0.896) , P<0.001). During the follow-up after orthopedic surgery, there were 19 patients with postoperative proximal junction failure, including 16 patients in the mismatched group (6 patients in the TLM<0.2 group, 10 patients in the TLM>0.5 group) and 3 patients in the matched group (0.2≤TLM≤0.5 group), with the incidence of 23% (16/71) and 6% (3/48), respectively. The difference was statistically significant (χ 2=5.66, P=0.017). Thoracolumbar mismatch was significantly associated with proximal borderline failure after orthosis [ OR=4.35, 95% CI (1.196, 15.924)]. Conclusion:The abnormal correction in thoracolumbar kyphosis and lower lumbar lordosis may result in mismatch between thoracolumbar segments, which would undermine the quality of life, and increase the incidence of proximal junctional failure developing in those ASD patients underwent long-fusion surgeries. The match between TLK and LLL should be 0.2 to 0.5.

Prevalence and distribution of ossification of ligamentum flavum at the adjacent segment of the apex in patients with degenerative kyphosis / 中华骨科杂志

Objective:To evaluate the prevalence and distribution of ossification of ligamentum flavum (OLF) at the segments adjacent to the apex in patients with degenerative kyphosis.Methods:All of 74 patients with degenerative kyphosis from January 2018 to December 2021 were retrospective reviewed. All patients were taken anteroposterior and lateral radiographs, CT scan and magnetic resonance imaging (MRI) of the entire spine. Global kyphosis, the morphology of kyphosis and the occurrence of OLF at three segments adjacent to the kyphosis apex were recorded.Results:Of the 74 patients, 54 patients (73%) developed OLF in three segments adjacent to the kyphotic apex. The mean age of the 54 patients was 61.4±6.8 years, and the mean global kyphosis was 49.5°±21.2°. Among other 20 patients without OLF, the mean age was 56.1±7.5 years, and the mean kyphosis angle was 52.1°±19.1°. There was a statistically significant difference in ages ( t=2.92, P=0.005), but no statistically significant difference was observed regarding global kyphosis ( t=0.48, P=0.634). In these 74 patients, 9 patients had angular kyphosis, of which 8 (89%) developed OLF; of the 65 patients without angular kyphosis, 46 patients (71%) developed OLF. There was no significant difference between them (χ 2=1.32, P=0.251). Among the 54 patients diagnosed with OLF, 5 patients (9%) suffered ossification of the posterior longitudinal ligament (OPLL) and 20 patients (37%) suffered dural ossification; 43 patients (80%) developed OLF at proximal segments of apex, 6 patient (11%) developed OLF at distal segments of apex, and 5 patients (9%) developed OLF both at proximal and distal segments of apex. Thirty-two patients (59%) developed OLF at the first segment adjacent to the kyphotic apex, 27 patients (50%) developed OLF at the second segment, and 15 patients (28%) developed OLF at the third segment. Conclusion:Among patients with degenerative kyphosis, about 73% may development OLF within three segments adjacent to the kyphotic apex, and it mostly occurred within two segments adjacent to the apex proximally.

Severe kyphoscoliosis patients with type III spinal cord on preoperative apex MRI: preoperative traction does improve the safety of correction surgery / 中华骨科杂志

Objective:To analyze the radiographic improvements after Halo-gravity traction in severe kyphoscoliosis patientswith type III spinal cord on preoperative apex MRI, and to assess the clinical outcomes and surgical safety of Halo-gravity traction in this cohort.Methods:A total of 47 severe thoracic kyphoscoliosis patients with type III spinal cord on preoperative apex MRI who underwent preoperative Halo-gravity traction followed by one-stage posterior spinal fusion from February 2019 to June 2021 in the Nanjing Drum Tower Hospital were retrospectively analyzed. There were 18 males and 29 females with an average age of 22.5±12.8 years (range, 9-60 years). The average duration of traction was 7.4±3.9 weeks (range, 4-16 weeks). Radiographic parameters were measured including the coronal Cobb angle, distance between C 7 plumb line and center sacral vertical line (C 7PL-CSVL), sagittalglobal kyphosis (GK) and sagittal vertical axis (SVA) atpre-traction, post-traction and post-operation, respectively. The traction correction rate was measured as "traction degree before traction-traction degree after traction)/traction degree before traction" and the surgical correction rate was represented as "traction degree before traction-postoperative degree)/ traction degree before traction". The Frankel scoring system was used for the evaluation of neurological status at pre-traction, post-traction and post-operation. Results:All of 47 patients underwent the Halo-gravity traction and posterior spinal correction surgery. The C 7PL-CSVL was 35.7±16.9 mm at initial visit. At post-operation, C 7PL-CSVL was improved to 22.0±13.7 mm ( t=13.75, P<0.001), and the improvement rate was 39.9%±15.5%. The GK was 110.9°±22.1° at initial visit, which was improved to 84.1°±19.9° ( t=8.84, P<0.001) after Halo-gravity traction with an average correction of 23.7%±8.9%. At post-operation, GK was improved to 65.3°±19.3° ( t=10.63, P<0.001), and the improvement rate were 40.1%±20.7%. The SVA was 43.8±19.5 mm at initial visit. At post-operation, SVA was improved to 21.1±14.9 mm ( t=10.32, P<0.001), and the improvement rate were 53.1%±27.0%. A total of 14 patients showed neurological deficits of lower limbs at pre-traction, of which 8 patients had significant neurological improvement after Halo gravity traction; 3 patients had significant neurological improvement after surgery, and the remaining 3 patients had no significant neurological improvement during treatment. No new neurological deficits were observed after Halo-gravity traction or surgery. Conclusion:For severe kyphoscoliosis patients with type III spinal cord on preoperative apex MRI, the Halo-gravity traction could effectively correct the deformity, improve neurological function, enhance the tolerance of spinal cord to surgery and reduce the risk of intraoperative iatrogenic neurological deficit.

Posterior vertebral column resection combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra / 中华创伤骨科杂志

Objective:To investigate the feasibility and clinical efficacy of posterior vertebral column resection (PVCR) combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra.Methods:From January 2017 to September 2021, 9 patients with stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra underwent PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column. Their medical records were retrospectively analyzed. There were 1 male and 8 females, aged (66.9±5.8) years. The injured vertebra was located at T 11 in 2 patients, at T 12 in 4, at L 1 in 2 and at L 2 in 1. X-ray, CT and MRI were performed before operation. The posterior intervertebral heights of adjacent vertebral bodies of the fractured vertebra in the median sagittal position were measured on CT or MRI to evaluate the shortening of the spinal column before PVCR. Recorded were intraoperative bleeding volume, operation time, complications, bone graft fusion, and American Spinal Injury Association (ASIA) grading at preoperation and the last follow-up. The visual analogue scale (VAS) pain scores, Oswestry disability index (ODI) scores, and kyphotic cobb angles at preoperation, 1 week and 3 months postoperation, and the last follow-up were compared to evaluate the clinical efficacy of PVCR. Results:All patients underwent surgery successfully, with tight closure of adjacent vertebrae after resection of the injured vertebra and bone grafting. Operation time was (240.6±23.2) min and intraoperative bleeding (505.6±95.0) mL. The 9 patients were followed up for (17.3±5.6) months. No worsening symptoms of nerve injury, cerebrospinal fluid leakage, or other serious complications were found after operation, nor such complications as loosening or breakage of internal fixation or adjacent vertebral fractures. Bone fusion was achieved at the bone graft sites in all patients by the last follow-up. The VAS and ODI scores and cobb angles at 1 week and 3 months postoperation and at the last follow-up were significantly decreased compared with preoperation ( P<0.05). There were no significant differences in VAS scores or cobb angles among postoperative 1 week and 3 months and the last follow-up ( P>0.05), but pairwise comparisons between different time points after operation showed significant differences in ODI, with postoperative 1 week > postoperative 3 months > the last follow-up ( P<0.05). The ASIA grading at the last follow-up was improved from preoperative grade C to grade D in 2 cases, from preoperative grade C to grade E in 1 case and from preoperative grade D to grade E in 5 cases. Conclusion:PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column is a feasible and effective surgical treatment for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra, leading to good clinical efficacy.

Percutaneous vertebral-disc plasty for very severe osteoporotic vertebral compression fractures / 中华创伤骨科杂志

Objective:To investigate the clinical efficacy of percutaneous vertebral-disc plasty (PVDP) in the treatment of very severe osteoporotic vertebral compression fractures (vsOVCF).Methods:A total of 26 patients with vsOVCF were treated by PVDP at Department of Spine Surgery, The Second Affiliated Hospital, Nantong University from November 2019 to August 2021. They were 8 males and 18 females with an age of (77.9±5.2) years. Fracture sites: T11 in 9 cases, T12 in 13 cases, L1 in 7 cases, and L2 in 2 cases. The loss of vertebral height exceeded 2/3 of its original height. The curative effects were evaluated by comparing the visual analogue scale (VAS), Oswestry disability index (ODI) and local kyphosis angle (LKA) at preoperation, 1 day postoperation and the last follow-up.Results:This cohort was followed up for 12(10, 15) months. No obvious neurological damage or other serious complications occurred. The VAS scores [(2.9±0.7) and (2.2±0.7) points] and ODIs [28.0%±4.8% and 16.9%±4.0%] at 1 day postoperation and the final follow-up were significantly lower than the preoperative values respectively [(6.7±0.8) points and 66.7%±6.0%], and the values at the last follow-up were significantly lower than those at 1 day postoperation ( P<0.05). The LKAs at 1 day postoperation and the last follow-up (18.1°±4.1° and 19.5°±4.4°) were significantly smaller than that before operation (32.0°±5.2°) ( P<0.05), but there was no significant difference between 1 day postoperation and the last follow-up in LKA ( P>0.05). Conclusion:PVDP is an effective surgical treatment of vsOVCF, because it can relieve pain and improve local kyphosis with satisfactory clinical outcomes.