Sagittal Alignment Concepts and Spinopelvic Parameters / Conceitos de alinhamento sagital e parâmetros espinopélvicos

Abstract Spinal surgery continues to expand its horizons to care for disabled patients presenting pain and deformities. Over the past decade, our knowledge of spinal alignment, from the skull to the pelvis, has increased considerably. Such knowledge must expand to reach general orthopedists and improve the care required for so many people. Global spinal alignment is a critical concept in understanding the impact of pathological conditions (degenerative diseases, traumas, deformities) and their treatment, including spinal instrumentation and arthrodesis. Therefore, the treatment of any spinal disease must include the knowledge of the complexity of the spinopelvic alignment. At first, all parameters seem like pure mathematics, hardly applicable to the everyday life of the inattentive reader. However, it gradually becomes clear that, like everything else in orthopedics, biomechanics is an essential part of the knowledge of the musculoskeletal system, revealing the logic behind the physiology of movements. The knowledge of the sagittal alignment concepts and spinopelvic parameteres provide a better comprehension of the axial and appendicular skeletons, increasing the understanding of the physiological and adaptive spinal processes in the face of the degenerative process that increases throughout life.

Resumo A cirurgia da coluna continua a expandir seus horizontes para cuidar dos pacientes incapacitados com dor e deformidades. Desde a última década, nosso conhecimento sobre o alinhamento espinal, do crânio à pelve, aumentou consideravelmente. Portanto, faz-se necessária a expansão de tal conhecimento para o ortopedista geral, para que possamos proporcionar melhores cuidados para essa população. O alinhamento espinal global é um conceito crítico no entendimento do impacto ocasionado pela condição patológica (doença degenerativa, trauma, deformidade) e mesmo do seu tratamento, como na instrumentação e artrodese da coluna. O tratamento de qualquer doença na coluna deve incluir o entendimento da complexidade do alinhamento espinopélvico. A princípio, todos os parâmetros parecem puramente matemáticos e pouco aplicáveis à realidade do leitor mais desatento. Mas, aos poucos, fica claro que, como tudo em ortopedia, a biomecânica faz parte essencial do conhecimento do sistema musculoesquelético, tornando mais claras as lógicas da fisiologia do movimento. O conhecimento dos conceitos de alinhamento sagital e dos parâmetros espinopélvicos proporcionam uma melhor compreensão dos esqueletos axial e apendicular, além de um melhor entendimento dos processos fisiológicos e adaptativos da coluna frente ao processo degenerativo crescente que ocorre ao longo da vida.

Measurement of spino-pelvic anatomical parameters and finite element analysis of lower lumbar vertebra in lumbarization patients / 解剖学报

Objective To measure the sagittal anatomical parameters of the spine and pelvis based on EOS imaging system, and to evaluate the stress of the lower lumbar spine by finite element analysis (FEA). Methods A total of 44 subjects examined by EOS imaging system were included, including 11 sacral lumbar vertebra patients and 33 normal subjects. The sagittal plane parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) were measured and compared in both groups. Pearson test was used to analyze the correlation between PI and LL in the two groups. At the same time, the finite element model of the lower lumbar vertebra was established. The stress condition of the lumbar spine model during forward bending, backward extension and left and right bending was evaluated by FEA method. Results The differences of PI, PT, SS and LL between the two groups were statistically significant (P<0.05). The correlation study found that there was a positive correlation between the two groups of subjects' PI and LL, including the lumbarization group (r = 0.69, P<0.05) and the normal group (r = 0.52, P<0.05). Under the conditions of forward bending, backward stretching, left bending and right bending, the bending moment of the model was 2 Nmm, and the stress concentration gradually decreased from bottom to top. The maximum stress concentration point was located at the lower articular process. Conclusion The physiological curvature and stress distribution of the lumbar spine in lumbarization population were different than normal, especially the stress concentration of the transitional intervertebral disc and articular process joint was obvious, and early degeneration of the spine was easy to occur.

Evaluation of the Radiographic Parameters of Sagittal and Spinopelvic Alignment in Patients with Osteoarthritis submitted to Total Hip Arthroplasty / Avaliação dos parâmetros radiográficos do alinhamento sagital e espinopélvico em pacientes com osteoartrite submetidos à artroplastia total do quadril

Abstract Objective To evaluate radiographic parameters of sagittal and spinopelvic alignment in patients with hip osteoarthritis (OA) undergoing primary total hip arthroplasty (THA) to define the primary surgical approach in individuals with concomitant spinal and hip joint disease. Methods Longitudinal, prospective, comparative study with 27 patients undergoing THA and 43 subjects without OA. Results An association between hip and spine degenerative disease in patients with OA was noted. After THA, radiographic parameters of pelvic tilt angle, sagittal vertical axis (EVS) and seventh cervical vertebra/sacrofemoral distance (C7/DSF) ratio were similar to values from volunteers without joint disease. Global coronal alignment (ACG), sagittal alignment, spinopelvic T1 and T9 tilts (IT1EP and IT9EP), sacral tilt (IS), pelvic version (VP), pelvic type and lumbopelvic complex (CLP) did not change after THA. Conclusion Among the sagittal and spinopelvic alignment parameters evaluated, the pelvic tilt angle, the EVS, and the C7/DSF ratio were corrected after THA and can guide the surgeon in the decision-making process for patients with concomitant spinal and hip joint disease. Spinal deformity may compensate for hip changes.

Resumo Objetivo Avaliar os parâmetros radiográficos do alinhamento sagital e espinopélvico de pacientes com osteoartrite (OA) de quadril submetidos à artroplastia total de quadril (ATQ) primária, com o intuito de definir a abordagem cirúrgica primária em pacientes com doença concomitante na coluna vertebral e na articulação do quadril. Métodos Estudo longitudinal, prospectivo, comparativo, envolvendo 27 pacientes submetidos à ATQ e 43 indivíduos sem OA. Resultados Foi observada associação entre doença degenerativa no quadril e na coluna nos pacientes com OA. Após a ATQ, os parâmetros radiográficos do ângulo da báscula da bacia, do eixo vertical sagital (EVS) e da razão de C7/DSF (sétima vértebra cervical/distância sacrofemoral) foram semelhantes aos valores dos voluntários sem doença articular. O alinhamento coronal global (ACG), o alinhamento sagital, as inclinações T1 e T9 espinopélvicas (IT1EP e IT9EP), a inclinação sacral (IS), a versão pélvica (VP), e o tipo de pelve e do complexo lombopélvico (CLP) não sofreram alteração depois da ATQ. Conclusão Dentre os parâmetros do alinhamento sagital e espinopélvico avaliados, o ângulo da báscula da bacia, o EVS e a razão C7/DSF foram corrigidos após a ATQ e podem orientar o cirurgião na tomada de decisão para pacientes com doença concomitante na coluna vertebral e na articulação do quadril. A deformidade da coluna pode ser compensatória às alterações do quadril.

Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis / 中国骨伤

OBJECTIVE@#To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients.@*METHODS@#The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS).@*RESULTS@#All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (<0.05).@*CONCLUSION@#Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

Analysis of spinopelvic sagittal parameters in degenerative lumbar spondylolisthesis / 第二军医大学学报

Objective To explore the characteristics of spinopelvic sagittal parameters in degenerative lumbar spondylolisthesis patients and the relationship between these parameters and lumbar spondylolisthesis. Methods From Jun. 2016 to Jun. 2018, 42 patients with degenerative lumbar spondylolisthesis (DLS) were enrolled in study group, and 58 degenerative lumbar disease patients without spondylolisthesis were enrolled in control group. The general characteristics of the patients were collected. The sagittal parameters, including pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL) and sagittal vertical axis (SVA), were measured on lateral X-ray films of full-length spine. The differences of general characteristics and sagittal parameters were compared between the two groups. With the lumbar spondylolisthesis rate as dependent variable and the spinopelvic sagittal parameter as independent variable, logistic regression model was used to analyze the risk factors of lumbar spondylolisthesis. Results There were no significant differences in the age, gender, height or body mass of the patients between the two groups (all P>0.05). There were significant differences in the PT, PI, SS, LL, TLK and SVA between the DLS group and the control group (all P0.05). Logistic regression analysis showed that LL and PT were risk factors of lumbar spondylolisthesis (both P<0.05). Conclusion The sagittal parameters (PT, PI, SS, LL, TLK and SVA) in the patients with DLS are significantly changed. LL and PT are the risk factors of lumbar spondylolisthesis.

Correlation between spinopelvic sagittal parameters and adjacent segment disease after lumbar fusion / 第二军医大学学报

Objective To analyze the correlation between adjacent segment disease (ASDis) after lumbar fusion and spinopelvic sagittal parameters, and to explore the risk factors. Methods From Jan. 2013 to Oct. 2017, the patients undergoing revision surgery for ASDis after lumbar fusion in Changhai Hospital of Naval Medical University (Second Military Medical University) were enrolled as ASDis group, and the patients who did not have ASDis after lumbar fusion during the same follow-up period were taken as controls. The clinical data of the patients in the two groups were retrospectively analyzed. The differences of the general data (age, gender, body mass index [BMI], follow-up time and the etiology of the first operation) and the spinopelvic sagittal parameters (thoracic kyphosis [TK], sagittal vertical axis [SVA], lumbar lordosis [LL], segmental lumbar lordosis [sLL], pelvic incidence [PI], pelvic tilt [PT] and sacral slope [SS]) were compared between the two groups. Results There were 25 patients in the ASDis group and 50 patients in the control group. There were no significant differences in the age, gender, BMI, follow-up time or the etiology of the first operation between the two groups (all P>0.05). Compared with the control group, the LL, sLL and SS were significantly lower in the ASDis group (36.00°±5.44°vs 43.88°±10.62°, 17.80°±5.79°vs 27.62°±6.74°, 27.50°±5.30°vs 31.06°±7.48° all P0.05). Meantime, the proportion of patients with SVA>50 mm, the difference of PT and LL (PT-LL)=10°, and the ratio of sLL to LL (RL)<60% were significantly higher in the ASDis group than those in the control group (18/25 vs 21/50, 16/25 vs 11/50, 21/25 vs 17/50; all P<0.05). Conclusion The sagittal imbalance after lumbar fusion is closely associated with ASDis, and compensatory kyphosis of adjacent lumbar segments due to surgical segmental lordosis may be one of the causes of ASDis after lumbar fusion.

Comparison of the Effects of Magnetically Controlled Growing Rod and Tradiotinal Growing Rod Techniques on the Sagittal Plane in the Treatment of Early-Onset Scoliosis

OBJECTIVE: Comparing the effects of magnetically controlled growing rod (MCGR) and traditional growing rod (TGR) techniques on the sagittal plane in the treatment of early-onset scoliosis (EOS).METHODS: Twelve patients were operated using dual MCGR technique in one center, while 15 patients were operated using dual TGR technique for EOS in another center. Patients’ demographic characteristics, complications and radiological measurements such as cobb angle, thoracic kyphosis, lumbar lordosis, T1–S1 range (mm), proximal junctional angle, distal junctional angle, sagittal balance, coronal balance, pelvic incidence, sacral slope and pelvic tilt were assessed and compared in preoperative, postoperative and last follow-up period.RESULTS: Age and sex distributions were similar in both groups. The mean number of lengthening in the MCGR group was 12 (8–15) and 4.8 (3–7) in the TGR group. Two techniques were shown to be effective in controlling the curvature and in the increase of T1–S1 distance. In TGR group, four patients had rod fractures, six patients had screw pull-out and four patients had an infection, whereas three patients had screw pull-out and one patient had infection complications in the MCGR group.CONCLUSION: There was no significant difference between the two groups in terms of cobb angle, coronal and sagittal balance and sagittal pelvic parameters. MCGR can cause hypokyphosis and proximal junctional kyphosis in a minimum 2-year follow-up period. The implant-related complications were less in the MCGR group. However, larger case groups and longer follow-up periods are required for the better understanding of the superiority of one method on other in terms of complications.

The Effects of Sagittal Spino-Pelvic Alignment on the Clinical Symptoms of Thoracolumbar Kyphosis in Osteoporotic Patients

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this study was to assess the effect of sagittal spino-pelvic alignment on the clinical symptoms of thoracolumbar kyphosis (TLK; T10-L2 Cobb's angle >20°) in osteoporotic patients. SUMMARY OF LITERATURE REVIEW: Few studies have investigated the clinical symptoms and radiological features of TLK caused by degenerative changes. There is also controversy over whether clinical symptoms will deteriorate in patients with TLK or which treatment should be chosen according to the degree of TLK. MATERIALS AND METHODS: From May 2005 to May 2016, we reviewed 75 patients who were diagnosed with TLK (T10-L2 Cobb's angle >20°) and osteoporosis. Patients were excluded from the study if they had neurological symptoms, underlying spinal disorders, or unstable vertebral fractures. Fifty patients with TLK due to an osteoporotic vertebral compression fracture (group F) and 25 patients with senile TLK (group S) were assessed by clinical symptoms and radiological parameters. Thoracolumbar kyphosis angle and sagittal vertical axis (SVA) were also analyzed. Clinical symptoms were assessed using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). RESULTS: There were no significant differences in clinical symptoms (VAS, ODI) and radiological parameters between groups F and S, or according to the degree of TLK(20°–30°, 30°–40°, >40°). Clinical symptoms were significantly more severe in patients with sagittal imbalance (SVA >5 cm) than in those with sagittal balance. CONCLUSIONS: Sagittal imbalance is a more important factor affecting clinical symptoms than the cause or the degree of TLK. Therefore, sagittal imbalance should be considered in the management of TLK in osteoporotic patients.

Effect of Spine-Pelvis Relationship in Total Hip Arthroplasty / 대한고관절학회지

When spine-pelvic motion is normally coordinated, the pelvis may tilt posteriorly and acetabular anteversion may increase as the patient's position changes from standing to sitting; this scenario allows for improved clearance of the femoral head and neck during hip flexion. However, changes in the mobility of the spine and pelvis may result in impingement after total hip arthroplasty (THA), with the most obvious complication being dislocation. Understanding the spinal-pelvic relationship in the sagittal plane is essential for planning THA in patients with spinal fusion or a known spine disease. Careful attention should be payed to the cup position when performing THA on patients with an increased risk of dynamic impingement.

Hypertension Is Related to Positive Global Sagittal Alignment: A Cross-Sectional Cohort Study

STUDY DESIGN: Cross-sectional cohort study.PURPOSE: This study aimed to investigate the relationship between hypertension and spino-pelvic sagittal alignment in middle-aged and elderly individuals.OVERVIEW OF LITERATURE: Positive global sagittal alignment is associated with poor health-related quality of life. Hypertension is associated with tissue microcirculation disorders of the skeletal muscle. We hypothesized that hypertension may be involved in positive global sagittal alignment.METHODS: In this institutional review board-approved study, 655 participants (262 men and 393 women; mean age, 72.9 years; range, 50–92 years) who underwent musculoskeletal screening in Toei town, Aichi, Japan were included. Whole spine and pelvic radiographs were taken, and radiographic parameters (thoracic kyphosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and sagittal vertical axis [SVA]) were measured using an image-analysis software. Hypertension was assessed using the standard criteria. The study participants were divided into three subgroups as per age (50–64 years, 65–74 years, and ≥75 years). We examined the differences in the radiographic parameters of those with and without hypertension in each age subgroup.RESULTS: In each age subgroup, there was no significant difference in the age and sex of those with and without hypertension. SVA was significantly shifted forward in the hypertension group than in the non-hypertension group in those aged 50–64 years old (32.4 mm vs. 16.0 mm, p=0.018) and in those aged 65–74 years old (42.7 mm vs. 30.6 mm, p=0.012). There was no significant difference between the hypertension and non-hypertension groups in terms of the alignment of the lumbar and thoracic spine in all the subgroups. In multivariate analysis, hypertension was a significant independent factor of forward-shifted SVA (standardized beta 0.093, p=0.015).CONCLUSIONS: This study showed that hypertension was associated with forward-shifted global sagittal alignment.

Prevention of Adjacent Segmental Disease after Fusion in Degenerative Spinal Disorder: Correlation between Segmental Lumbar Lordosis Ratio and Pelvic Incidence–Lumbar Lordosis Mismatch for a Minimum 5-Year Follow-up

STUDY DESIGN: Retrospective study. PURPOSE: Associations among risk factors related to adjacent segmental disease (ASD) remain unclear. We evaluated the risk factors and segmental lordosis ratio to prevent ASD developing after lumbar spinal fusion. OVERVIEW OF LITERATURE: Risk factors related to ASD development are age, sex, obesity, pre-existing degeneration, number of fusion segments, and decreased postoperative lumbar lordosis (LL). However, the associations among these factors are still unclear and should be clearly identified. METHODS: We retrospectively reviewed data on 274 patients who underwent lumbar spinal fusion of three segments or below for lumbar degenerative disease from January 2010 to December 2012, with over 5 years of follow-up. Patients with preoperative sagittal vertical axis (SVA) >5 cm were excluded due to sagittal imbalance. A total of 37 patients with ASD and 40 control patients (CTRL) were randomly selected in a similar distribution of matching variables: age, sex, and preoperative degenerative changes. Sex, age, number of fusion segments, radiologic measurements, L4–5–S1/L1–S1 LL ratio, and spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and SVA) were analyzed. Logistic regression was used to analyze the correlation between PI–LL mismatch and L4–5–S1 segmental lordosis rate. RESULTS: No significant difference was found between ASDs and CTRL groups regarding age, sex, number of fusion segments, fusion method, and preoperative and postoperative spinopelvic parameters (PI, SS, PT, and LL). However, regarding the L4–5–S1/L1–S1 lordosis ratio, 50% (p=0.045), 60% (p=0.031), 70% (p=0.042), 80% (p=0.023), and 90% (p=0.023) were statistically significant; 10 group, and the difference was statistically significant (p=0.048). CONCLUSIONS: Patients with a postoperative L4–5–S1/L1–S1 lordosis ratio >50% had less occurrence of ASD. Correcting LL according to PI and physiologic segmental lordosis ratio is important in preventing ASD.

Effects of Sagittal Spinopelvic Alignment on Motor Symptom and Respiratory Function in Mild to Moderate Parkinson's disease

PURPOSE: This study examined the effects of sagittal spinopelvic alignment on the clinical parameters, motor symptoms, and respiratory function in patients with mild to moderate Parkinson's disease (PD). METHODS: This study was a prospective assessment of treated patients (n=28, Hoehn and Yahr (H&Y) stage 2–3) in a PD center. Twenty-eight subjects (68.5±5.7 yrs) participated in this study. The clinical and demographic parameters, including age, sex, symptoms duration, treatment duration, and H&Y stage, were collected. Kinematic analysis was conducted in the upright standing posture with a motion capture system. A pulmonary function test (PFT) was performed in the sitting position using a spirometer. The motor symptoms were assessed on part III of the movement disorder society sponsored version of the unified Parkinson's disease rating scale (MDS-UPDRS). SPSS 18.0 was used to analyze the collected data. RESULTS: The exceeding 12 degrees group of the lower trunk showed significantly higher on the clinical parameters than the below 12 degrees group. In addition, the exceeding 12 degrees group of the lower trunk showed a significantly lower forced expiratory volume at one second (FEV1) / forced vital capacity (FVC) (%) and 25–75% forced mid-expiratory flow (FEF) (L/s) than in the below group. On the other hand, there was no difference in the upper trunk and the cervical pelvis between the groups. CONCLUSION: These findings suggest that the sagittal balance in the lower trunk is related to the clinical parameters and respiratory function, but not the motor symptoms in patients with mild to moderate PD.

Comparison of the Effects of Magnetically Controlled Growing Rod and Tradiotinal Growing Rod Techniques on the Sagittal Plane in the Treatment of Early-Onset Scoliosis

OBJECTIVE: Comparing the effects of magnetically controlled growing rod (MCGR) and traditional growing rod (TGR) techniques on the sagittal plane in the treatment of early-onset scoliosis (EOS). METHODS: Twelve patients were operated using dual MCGR technique in one center, while 15 patients were operated using dual TGR technique for EOS in another center. Patients’ demographic characteristics, complications and radiological measurements such as cobb angle, thoracic kyphosis, lumbar lordosis, T1–S1 range (mm), proximal junctional angle, distal junctional angle, sagittal balance, coronal balance, pelvic incidence, sacral slope and pelvic tilt were assessed and compared in preoperative, postoperative and last follow-up period. RESULTS: Age and sex distributions were similar in both groups. The mean number of lengthening in the MCGR group was 12 (8–15) and 4.8 (3–7) in the TGR group. Two techniques were shown to be effective in controlling the curvature and in the increase of T1–S1 distance. In TGR group, four patients had rod fractures, six patients had screw pull-out and four patients had an infection, whereas three patients had screw pull-out and one patient had infection complications in the MCGR group. CONCLUSION: There was no significant difference between the two groups in terms of cobb angle, coronal and sagittal balance and sagittal pelvic parameters. MCGR can cause hypokyphosis and proximal junctional kyphosis in a minimum 2-year follow-up period. The implant-related complications were less in the MCGR group. However, larger case groups and longer follow-up periods are required for the better understanding of the superiority of one method on other in terms of complications.

Effects of fresh lumbar osteoporotic vertebral compression fracture on spinopelvic sagittal parameters and distribution of Roussouly types / 中华创伤骨科杂志

Objective To investigate the effects of fresh lumbar osteoporotic vertebral compression fracture (OVCF) on spinopelvic sagittal parameters and distribution of Roussouly types.Methods One hundred and eight patients with one-level fresh lumbar OVCF and 110 patients with simple osteoporosis (OP) were diagnosed and treated at Department of Orthopedic Surgery,Shougang Hospital from January 2016 to August 2017.The basic clinical data of all the patients were documented and their lumber spines were classified by Roussouly types.The 2 groups were compared in terms of spinopelvic sagittal parameters such as pelvic incidence (PI),pelvic tilt (PT),sacral slope (SS),and lumbar lordosis (LL) and Roussouly types.The correlation between Roussouly types and fracture segments was observed in OVCF group.Results There was no significant different in PI between OVCF and OP groups (50.35° ± 11.00° versus 51.96° ± 11.73°) (P ＞ 0.05).PT in OVCF group (18.79°± 9.51°) was significantly larger than that (16.19°± 9.03°) in OP group while SS (31.56° ± 7.88°) and LL (40.22°± 12.29°) in the former significantly smaller than those in the latter (35.77° ± 8.82° and 47.89° ± 13.20°,respectively) (P ＜ 0.05).Roussouly types Ⅰ,Ⅱ,Ⅲ and Ⅳ in OVCF group were 35,40,28 and 5 cases,respectively,with types Ⅰ and Ⅱ accounting for 69.5％;Roussouly types Ⅰ,Ⅱ,Ⅲ and Ⅳ in OP group were 17,30,49 and 14 cases,respectively,with type Ⅲ being predominant (44.5％).There was a significant difference between the 2 groups in distribution of Roussouly types (P ＜03.05).In OVCF group,fractures of L1 and L2 vertebrae accounted for 82.4％.There was a significant correlation between fracture segments and lumbar Roussouly types (P =0.034).Conclusions Patients with fresh lumbar OVCF tend to have a forward gravity and sagittal disequilibrium,leading to posterior pelvic rotation,increased PT,decreased SS,and downward shift of the apex of the lumbar curve.Their Roussouly classification is mainly type Ⅰ or type Ⅱ.

Spino-Pelvic Fixation in Unstable Sacral Fracture: A Case Report

A 22-year-old female patient visited the emergency room (ER) after a pedestrian traffic accident in a drunken state. An examination at the ER revealed fractures at the right side of the sacral ala, sacral foramina, left anterior acetabulum, right inferior ramus, and right superior articular process of S1. She underwent spino-pelvic fixation and iliosacral (IS) screw fixation. One year later, bone union was completed and implant removal was performed and the treatment was completed without complications. The authors recommend spino-pelvic fixation and IS screw fixation for unstable sacral fractures as one of the excellent methods for obtaining posterior stability of the pelvis among the various treatments of unstable sacral fractures.

Influence of Distal Fusion Level on Sagittal Spinopelvic and Spinal Parameters in the Surgical Management of Adolescent Idiopathic Scoliosis

STUDY DESIGN: Retrospective analysis of adolescent idiopathic scoliosis. PURPOSE: This study aimed to investigate the influence of distinct distal fusion levels on spinopelvic parameters in patients with adolescent idiopathic scoliosis (AIS) who underwent posterior instrumentation and fusion surgery. OVERVIEW OF LITERATURE: The distal fusion level selection in treatment of AIS is the one of milestone to effect on surgical outcome. Most of the paper focused on the coronal deformity correction and balance. The literature have lack of knowledge about spinopelvic changing after surgical treatment and the relation with distal fusion level. We evaluate the spinopelvic and pelvic parameter alteration after fusion surgery in treatment of AIS. METHODS: A total of 100 patients with AIS (88 females and 12 males) were retrospectively reviewed. Patients were assigned into the following three groups according to the distal fusion level: lumbar 2 (L2), lumbar 3 (L3), and lumbar 4 (L4). Using a lateral plane radiograph of the whole spine, spinopelvic angular parameters such as thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were radiologically assessed. RESULTS: The mean age was 15±2.4 years, and the mean follow-up period was 24.27±11.69 months. Regarding the lowest instrumented vertebra, patients were categorized as follows: 30 patients in L2 (group 1), 40 patients in L3 (group 2), and 30 patients in L4 (group 3). TK decreased from 36.60±13.30 degrees preoperatively to 26.00±7.3 degrees postoperatively in each group (p=0.001). LL decreased from 52.8±9.4 degrees preoperatively to 44.30±7.50 degrees postoperatively (p=0.001). Although PI showed no difference preoperatively among the groups, it was statistically higher postoperatively in group 3 than in the other groups (p 0.05). However, mean SS was significantly higher in group 3 (p=0.042, p < 0.05). PT decreased from 15.50±7.90 degrees preoperatively to 15.2±7.10 degrees postoperatively. The positive relationship (28.5%) between LL and PI measurements was statistically significant (r=0.285; p=0.004, p < 0.01). Furthermore, the positive relationship (36.5%) between LL and SS measurements was statistically significant (r=0.365; p=0.001, p < 0.01). CONCLUSIONS: When the distal instrumentation level in AIS surgery is below L3, a significant change in PT and SS (pelvic parameters) is anticipated.

Difference of spino-pelvic sagittal alignment between lumbar disc herniation and lumbar canal stenosis in adults / 中国骨伤

<p><b>OBJECTIVE</b>To study the difference of spino-pelvic sagittal alignment between lumbar disc herniation(LDH) and lumbar canal stenosis(LCS) in adults.</p><p><b>METHODS</b>The integrated imaging data of 88 patients with lumbar disc herniation (42 cases) or lumbar canal stenosis(46 cases) were searched from January 1, 2015 to September 10, 2016 in our hospital.Twenty-two cases were excluded because of age factor, 36 cases of LDH (LDH group) and 30 cases of LCS (LCS group) were internalized in the study. The spino-pelvic parameters were measured including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), thoracolumbar junction (TLJ), sagittal vertical axis (SVA), sagittal vertical axis location (SVA-Location), T₁-spinopelvic inclination (T₁-SPI), T9-spinopelvic inclination (T₉-SPI). Independent sampletest was used in order to analyze the above data.</p><p><b>RESULTS</b>Thoracic kyphosis (TK) in LDH group was smaller than that of LCS group (difference was about 6 degree), there was significant difference between two groups (=0.031). And there were no significant differences in other parameters between two groups (>0.05).</p><p><b>CONCLUSIONS</b>The patients with lumbar disc herniation, the kyphosis of the thoracic spine is smaller, the truncus prones to the straight. The lumbar kyphosis is greater in patients with lumbar spinal stenosis, and the sagittal curvature of the lumbar spine is more obvious.</p>

Comparison of clinical complications of iliac screw fixation versus S2 alar-iliac screw / 局解手术学杂志

Objective To compare the clinical complications between S2 alar-iliac(S2AI) screw and iliac screw(IS) fixation technique.Methods The data of 65 patients who were diagnosed as degenerative scoliosis and underwent spinopelvic fixation in our hospital from August 2010 to July 2012 were retrospectively reviewed.These patients were divided into the iliac screw fixation group (IS group) with 43 patients and the S2 alar iliac fixation group (S2AI group) with 22 patients according to different methods.The complications included screw loosening,screw breakage,acute infections,delayed wound infection and persistent pain over the gluteal region occurring longer than 3 months postoperatively were recorded.Results There were 8cases with screw loosening and 13 cases with gluteal pain in IS group,while there were no screw loosening and only 2 cases with gluteal pain in S2AI group.The average onset of gluteal pain were 11.8 months postoperatively in the IS group and 18 months postoperatively in the S2AI group.It showed that the absolute risk reduction(ARR) of screw loosening and late pain in the S2AI group was 18.6%,which was lower than 21.1% in the IS group. In the IS group, there were a total of 5 cases of delayed wound infection. Finally,3 caes of them were cured by irrigation and debridement only.and the other 2 cases were cured by irrigation and debridement with implant removal.There were no cases of delayed wound infection in the S2AI group.Conclusion The S2AI technique is associated with significantly less clinical and radiographic complications when compared with the iliac screws technique,it is a kind of internal fixation of spine and pelvis,which is worthy of being popularized by spine surgeons.

Difference in measured parameters on spino-pelvic sagittal plane of X-ray film between middle-aged or elderly patients with lumbar spondylolysis and with isthmic spondylolisthesis and its clinical value / 实用放射学杂志

Objective To investigate the differences in some measured paremeters on spino-pelvic sagittal X-ray films in middle-aged and elderly patients between lumbar spondylolysis and isthmic spondylolisthesis,and to explore the predictors that the spondylolysis at lumbar 5 may develope into spondylolisthesis in order to provide imaging details for the clinical treatment of teenage patients with lumbar spondylolysis.Methods Imaging data of 60 patients with spondylolysis at lumbar 5 and other 60 with isthmic spondylolisthesis in middle or elder age in our hospital were analyzed retrospectively,and a control group with 60 normal volunteers were recruited in this study.Some parameters including the angles of pelvic incidence (PI),pelvic tilt (PT),sacral slope (SS),lumbar-sacral angle (LSA)and lumbar lordosis (LL),and the sagittal vertical axis (SVA)were measured in sagittal radiographs of the spine and pelvis. Differences in sagittal parameters among 3 groups were analyzed by one-way variance analysis and SNK-q test.Results The PI,PT, SS and LL were higher,and LSA was lower in patients with isthmic spondylolisthesis than those in the control group and lumbar spondylolysis one (P0.05).No significant differences in all spino-pelvic sagittal parameters were found between lumbar spondylolysis group and the control (P>0.05).Conclusion Such spino-pelvic sagit-tal parameters as PI,PT,SS,LL and LSA on X-ray film can be regarded as predictors that lumbar 5 spondylolysis may develop into spondylolisthesis and may provide imaging reference for the clinical treatment of teen-age patients with lumbar spondylolysis.

Spinopelvic Alignment and Lumbar Diseases(review) / 中国康复理论与实践

The spinopelvic alignment(SPA)closely relates to lumbar disease.This paper summarized various kinds of SPA parameters, introduced a new measure of computer motion analysis system.Most of patients with lumbar disc degeneration are found the lumbar lordo-sis decreasing,which indicates pelvic tilt and trunk anteversion.However,no obviously SPA varieties are found in patients with lumbar spi-nal stenosis and nonspecific low back pain.The SPA parameters can also be used as indices for evaluation of treatment for lumbar disease. Future researches may focus on selection of SPA parameters,noninvasive measurements,relationship to lumbar disease and application of SPA for evaluation of interventions.