Increasing pelvic incidence is associated with more global sagittal imbalance in ankylosing spondylitis with thoracolumbar kyphosis

Abstract Background: Ankylosing spondylitis (AS) patients with kyphosis have an abnormal spinopelvic alignment and pelvic morphology. Most of them focus on the relationship of pelvic tilt (PT) or sacral slope (SS) and deformity, and relatively few studies have addressed the relationship between pelvic incidence (PI) and kyphosis in AS patients. The purpose of this study is to analyze the correlation between pelvic incidence (PI) and the spinopelvic parameters describing local deformity or global sagittal balance in AS patients with thoracolumbar kyphosis. Methods: A total of 94 patients with AS (91 males and 3 females) and 30 controls were reviewed. Sagittal spinopelvic parameters, including PI, PT, SS, thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis(LL), sagittal vertical axis(SVA), T1 pelvic angle(TPA), spinosacral angle(SSA) and spinopelvic angle(SPA) were measured. Statistical analysis was performed to identify the correlation of PI with other parameters. Results: Compared with the control group, the AS patients had significantly higher PI(47.4˚ vs. 43.2˚, P<0.001). PI in AS patients was found to be significantly positively correlated with TPA(r=0.533, R 2 =0.284, P<0.001), and negatively correlated with SPA(r=-0.504, R 2 =0.254, P<0.001). However, no correlations were found between PI and SVA, SSA, TK, TLK or LL in AS patients. Conclusion: The value of PI in AS patients with kyphosis was significantly higher than that of controls. Correlation analysis revealed that increasing PI was significantly correlated with more global sagittal imbalance, not with the local deformity in AS patients with thoracolumbar kyphosis.

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Increasing pelvic incidence is associated with more global sagittal imbalance in ankylosing spondylitis with thoracolumbar kyphosis: an observational retrospective study of 94 cases

10.21203/rs.2.16543/v3 ◽

2020 ◽

Author(s):

Diyu Song ◽

Guoquan Zheng ◽

Tianhao Wang ◽

Dengbin Qi ◽

Yan Wang

Keyword(s):

Ankylosing Spondylitis ◽

Pelvic Incidence ◽

Pearson Correlation ◽

Control Group ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Thoracolumbar Kyphosis ◽

Spinopelvic Parameters ◽

Sagittal Vertical Axis ◽

The Relationship

Abstract Background: Ankylosing spondylitis (AS) patients with kyphosis have an abnormal spinopelvic alignment and pelvic morphology. Most studies focus on the relationship of pelvic tilt (PT) or sacral slope (SS) and deformity, and relatively few studies have addressed the relationship between pelvic incidence (PI) and kyphosis in AS patients. The purpose of this study is to analyze the correlation between pelvic incidence (PI) and the spinopelvic parameters describing local deformity or global sagittal balance in AS patients with thoracolumbar kyphosis.Methods: A total of 94 patients with AS (91 males and 3 females) and 30 controls (27 males and 3 females) were reviewed. The mean age was 36.8 years in AS patients and 34.4 years in controls. Gender ratios and mean age were similar in both group. Sagittal spinopelvic parameters, including PI, PT, SS, thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis(LL), sagittal vertical axis(SVA), the first thoracic vertebra pelvic angle(TPA), spinosacral angle(SSA) and spinopelvic angle(SPA) were measured. The same spine surgeons measured all the parameters of the AS and control group. All the sagittal spinopelvic parameters were compared between the groups. The relationship between PI and other spinopelvic parameters was analyzed with Pearson correlation (r) and unary linear regression model.Results: All the sagittal parameters were found to be significantly different between AS patients and controls. Compared with the control group, the AS patients had significantly higher PI(47.4˚ vs. 43.2˚, P<0.001). Correlation analysis revealed that PI in AS patients was significantly positively correlated with TPA(r=0.533, R2=0.284, P<0.001), and negatively correlated with SPA(r=-0.504, R2=0.254, P<0.001). However, no correlations were found between PI and SVA, SSA, TK, TLK or LL in AS patients.Conclusion: This study revealed that increasing PI was significantly correlated with more global sagittal imbalance, not with the local deformity in AS patients with thoracolumbar kyphosis.

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Increasing pelvic incidence is associated with more global sagittal imbalance in ankylosing spondylitis with thoracolumbar kyphosis

10.21203/rs.2.16543/v2 ◽

2019 ◽

Author(s):

Diyu Song ◽

Guoquan Zheng ◽

Tianhao Wang ◽

Dengbin Qi ◽

Yan Wang

Keyword(s):

Ankylosing Spondylitis ◽

Sagittal Balance ◽

Pelvic Incidence ◽

Pearson Correlation ◽

Control Group ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Thoracolumbar Kyphosis ◽

Spinopelvic Parameters ◽

The Relationship

Abstract Background: Ankylosing spondylitis (AS) patients with kyphosis have an abnormal spinopelvic alignment and pelvic morphology. Most studies focus on the relationship of pelvic tilt (PT) or sacral slope (SS) and deformity, and relatively few studies have addressed the relationship between pelvic incidence (PI) and kyphosis in AS patients. The purpose of this study is to analyze the correlation between pelvic incidence (PI) and the spinopelvic parameters describing local deformity or global sagittal balance in AS patients with thoracolumbar kyphosis. Methods: A total of 94 patients with AS (91 males and 3 females) and 30 controls were reviewed. Sagittal spinopelvic parameters, including PI, PT, SS, thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis(LL), sagittal vertical axis(SVA), the first thoracic vertebra pelvic angle(TPA), spinosacral angle(SSA) and spinopelvic angle(SPA) were measured. Pearson correlation (r) and unary linear regression model were used to analysis the relationship between PI and other spinopelvic parameters. Results: Compared with the control group, the AS patients had significantly higher PI(47.4˚ vs. 43.2˚, P<0.001). PI in AS patients was found to be significantly positively correlated with TPA(r=0.533, R2=0.284, P<0.001), and negatively correlated with SPA(r=-0.504, R2=0.254, P<0.001). However, no correlations were found between PI and SVA, SSA, TK, TLK or LL in AS patients. Conclusion: This study revealed that increasing PI was significantly correlated with more global sagittal imbalance, not with the local deformity in AS patients with thoracolumbar kyphosis. Key Words: ankylosing spondylitis, pelvic incidence, sagittal spinopelvic parameters, global sagittal balance

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Implications of Spinopelvic Alignment for the Spine Surgeon

Neurosurgery ◽

10.1227/neu.0b013e31823262ea ◽

2011 ◽

Vol 70 (3) ◽

pp. 707-721 ◽

Cited By ~ 55

Author(s):

Vivek A. Mehta ◽

Anubhav Amin ◽

Ibrahim Omeis ◽

Ziya L. Gokaslan ◽

Oren N. Gottfried

Keyword(s):

Sagittal Balance ◽

Lumbar Lordosis ◽

Pelvic Incidence ◽

Degenerative Spondylolisthesis ◽

Disease Process ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Spinopelvic Parameters ◽

Spinopelvic Alignment ◽

Spinopelvic Balance

Abstract The relation of the pelvis to the spine has previously been overlooked as a contributor to sagittal balance. However, it is now recognized that spinopelvic alignment is important to maintain an energy-efficient posture in normal and disease states. The pelvis is characterized by an important anatomic landmark, the pelvic incidence (PI). The PI does not change after adolescence, and it directly influences pelvic alignment, including the parameters of pelvic tilt (PT) and sacral slope (SS) (PI = PT 1 SS), overall sagittal spinal balance, and lumbar lordosis. In the setting of an elevated PI, the spineadapts with increased lumbar lordosis. To prevent or limit sagittal imbalance, the spine may also compensate with increased PT or pelvic retroversion to attempt to maintain anupright posture. Abnormal spinopelvic parameters contribute to multiple spinal conditions including isthmic spondylolysis, degenerative spondylolisthesis, deformity, and impact outcome after spinal fusion. Sagittal balance, pelvic incidence, and all spinopelvic parameters are easily and reliably measured on standing, full-spine (lateral) radiographs, and it is essential to accurately assess and measure these sagittal values to understand their potential role in the disease process, and to promote spinopelvic balance at surgery. In this article, we provide a comprehensive review of the literature regarding the implications of abnormal spinopelvic parameters and discuss surgical strategies for correction of sagittal balance. Additionally, the authors rate and critique the quality of the literature cited in a systematic review approach to give the reader an estimate of the veracity of the conclusions reached from these reports.

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Implications of Spinopelvic Alignment for the Spine Surgeon

Neurosurgery ◽

10.1227/01.neu.0000462077.50830.1a ◽

2011 ◽

Vol 76 (suppl_1) ◽

pp. S42-S56 ◽

Cited By ~ 29

Author(s):

Vivek A. Mehta ◽

Anubhav Amin ◽

Ibrahim Omeis ◽

Ziya L. Gokaslan ◽

Oren N. Gottfried

Keyword(s):

Sagittal Balance ◽

Lumbar Lordosis ◽

Pelvic Incidence ◽

Degenerative Spondylolisthesis ◽

Disease Process ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Spinopelvic Parameters ◽

Spinopelvic Alignment ◽

Spinopelvic Balance

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Effect of sagittal imbalance on functional disability in patients with degenerative spondylolisthesis

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20195794 ◽

2019 ◽

Vol 6 (1) ◽

pp. 31

Author(s):

Ramdas Maloth

Keyword(s):

Functional Disability ◽

Pelvic Incidence ◽

Sagittal Plane ◽

Degenerative Spondylolisthesis ◽

Vertical Axis ◽

P Value ◽

Sagittal Imbalance ◽

Sagittal Vertical Axis ◽

Cross Sectional ◽

Digital Radiograph

Background: Deformity of spine in sagittal plane is a major cause of pain and disability among patients presenting with low back pain to spine clinic. We have studied the effect of spinal sagittal imbalance on functional disability in these patients.Methods: Cross sectional observational study in 50 patients with degenerative spondylolisthesis of more than 45 years age group study done in period of1 years. Subjects underwent standing lateral radiographs of the spine in a relaxed position, facing forward, with their knees maximally extended and their arms raised horizontally forward resting on a support. 2 radiographic films are stitched at baseline using digital radiograph operating console (DROC) software.Results: In our study out of 50 patients we observed female preponderance, female:male 3:1, degenerative spondylolisthesis more commonly involves L4-L5 level (46 patients). 58% of patients with severe degenerative spondylolisthesis. There is significant correlation between sagittal vertical axis (SVA) and severity (p=0.015) in both grade 1 and grade 2 DS, there is significant correlation between pi and functional disability (p=0.001 and 0.010 respectively) it is found that pelvic tilt with p=0.02 and sagittal vertical axis with p value 0.036 are the two most significant variables at the end of backward elimination analysis.Conclusions: Sagittal imbalance is seen in degenerative spondylolisthesis which needs further evaluation with spinopelvic parameters. Pelvic incidence and sagittal vertebral axis are important determinants of functional disability in patients with degenerative spondylolisthesis. Individuals with high pelvic incidence and more lumbo pelvic kyphosis showed more functional disability compared to others.

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Global sagittal spinal alignment at cervical flexion in patients with dropped head syndrome

Journal of Orthopaedic Surgery ◽

10.1177/2309499020948266 ◽

2020 ◽

Vol 28 (3) ◽

pp. 230949902094826 ◽

Cited By ~ 1

Author(s):

Takamitsu Konishi ◽

Kenji Endo ◽

Takato Aihara ◽

Hidekazu Suzuki ◽

Yuji Matsuoka ◽

...

Keyword(s):

Thoracic Spine ◽

Vertical Axis ◽

Control Group ◽

Sacral Slope ◽

Neutral Position ◽

Spinal Alignment ◽

Sagittal Vertical Axis ◽

Dropped Head Syndrome ◽

Sagittal Spinal Alignment ◽

Significant Difference

Purpose: Dropped head syndrome (DHS) is characterized by the passively correctable chin-on-chest deformity. The characteristic feature is emphasized in the cervical flexion position. The purpose of this study was to analyze the influence of cervical flexion on sagittal spinal alignment in patients with DHS. Methods: The study included 15 DHS subjects and 55 cervical spondylosis (CS) subjects as the control group. The following parameters were analyzed: cervical sagittal vertical axis (C-SVA), occipitoaxial angle (O–C2A), C2 slope (C2S), C2–C7 angle (C2–C7A), T1 slope (T1S), sagittal vertical axis, T1–T4 angle (T1–T4A), T5–T8 angle (T5–T8A), T9–T12 angle, lumbar lordosis, sacral slope, and pelvic tilt, in cervical flexion and neutral positions. Results: The values of C-SVA, O–C2A, C2S, and T1S were significantly different between CS and DHS at cervical neutral and flexion positions. C2–C7A showed significant difference in cervical neutral position, but the difference disappeared in flexion position. T1–T4A did not present a significant difference, but T5–T8A showed a difference in neutral and flexion positions. Conclusions: Malalignment of DHS extended not only to cervical spine but also to cranio-cervical junction and thoracic spine, except T1–T4. It is known that global sagittal spinal alignment is correlated with adjacent parameters, although in DHS the reciprocal change was lost from cranio-cervical junction to the middle part of thoracic spine at cervical flexion.

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The change of sagital balance after PKP for patients with osteoporotic vertebral compression

10.21203/rs.3.rs-16771/v1 ◽

2020 ◽

Author(s):

Jingkun Li ◽

Kaining Zhang ◽

Yanjun Ren ◽

Yingguang Wu ◽

Yun Yang ◽

...

Keyword(s):

Vertebral Body ◽

Vertebral Compression Fracture ◽

Body Height ◽

Compression Fracture ◽

Vertical Axis ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Vertebral Body Height ◽

Sagittal Vertical Axis ◽

Before And After

Abstract Purpose To detect the postoperative change in total spinal alignment in 0VCF patients after PKP. Methods A total of 130 patients with vertebral compression fracture was involved in this study. The entire spine radiographs of every patients were taken pre and postoperatively. The parameters including vertebral body height, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), sagittal vertical axis (SVA), and spinosacral angle (SSA). All the parameters were compared before and after PKP. Results In the patients, the VAS score was decreased from 8.26±1.12 preoperative to 2.70±0.90 postoperative. And SVA decreased from 6.82±3.30 cm to 4.07±2.77cm. The change in sagittal balance is related to the recovery of vertebral body height. Conclusion PKP plays a role not only in improving the vertebral body height but also in rebuilding sagittal imbalance in the treatment of vertebral compression fracture.

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Sagittal alignment based on inflection point and its differences according to age groups

Journal of Orthopaedic Surgery ◽

10.1177/2309499020904615 ◽

2020 ◽

Vol 28 (1) ◽

pp. 230949902090461

Author(s):

Moon Soo Park ◽

Seong-Hwan Moon ◽

Tae-Hwan Kim ◽

Jae Keun Oh ◽

Seung Jin Lee ◽

...

Keyword(s):

Pelvic Incidence ◽

Sagittal Plane ◽

Sagittal Alignment ◽

Age Groups ◽

Vertical Axis ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Inflection Points ◽

Lumbar Segment ◽

Cervical Segment

Purpose: We have always used the standard anatomical landmark vertebrae to measure the sagittal alignment. Instead, scoliosis has been evaluated by the end vertebrae in the coronal plane. There have been clinical studies to investigate sagittal alignment on the end vertebrae of inflection points (IPs). The purpose is to determine sagittal alignment based on IPs and to elucidate the changes while considering age groups. Methods: We identified the most titled vertebrae in the sagittal plane to define the end vertebrae of S1, thoracolumbar and cervicothoracic IPs and to measure the Cobb angles of sacral slope, functional lumbar, thoracic, cervical segment between them, and the McGregor’s line, and the IP distances from the C2 plumb line to the point bisecting the upper end plate of the IPs, in addition to S1. Results: The most common thoracolumbar and cervicothoracic IPs were L2 and T1, respectively. However, the next most common cervicothoracic IP changed from T2 in the youngest to C7 in the oldest age group. The sagittal angles decreased at the sacral slope and functional lumbar segment but not the functional thoracic segment and functional cervical segment. Similarly, the distance increased at the C2 sagittal vertical axis (SVA) distance to S1 and thoracolumbar IP distance but not at the cervicothoracic IP distance. There was no difference in the pelvic incidence among age groups. Conclusion: The sagittal Cobb angles based on the IPs decreased at the sacral slope and functional lumbar segment in the older adults. Consequently, the C2 SVA distance to S1 and thoracolumbar IP distance increased.

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Can posterior stand-alone expandable cages safely restore lumbar lordosis? A minimum 5-year follow-up study

10.21203/rs.3.rs-27368/v3 ◽

2020 ◽

Author(s):

Seung-Kook Kim ◽

Ogeil Mubarak Elbashier ◽

Su-chan Lee ◽

Woo-jin Choi

Keyword(s):

Sagittal Balance ◽

Lumbar Lordosis ◽

Vertical Axis ◽

Control Group ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Expandable Cage ◽

Cage Group

Abstract Background: Lumbar lordosis (LL) can be restored, and screw-related complications may be avoided with the stand-alone expandable cage method. However, the long-term spinopelvic changes and safety remain unknown. We aimed to elucidate the long-term radiologic outcomes and safety of this technique. Methods: Data from patients who underwent multi-level stand-alone expandable cage fusion and 80 patients who underwent screw-assisted fusion between February 2007 and December 2012, with at least 5 years of follow-up, were retrospectively analyzed. Segmental angle and translation, short and whole LL, pelvic incidence, pelvic tilt, sacral slope (SS), sagittal vertical axis, thoracic kyphosis, and presence of subsidence, pseudoarthrosis, retropulsion, cage breakage, proximal junctional kyphosis (PJK), and screw malposition were assessed. The relationship between local, lumbar, and spinopelvic effects was investigated. The implant failure rate was considered a measure of procedure effectiveness and safety. Results: In total, 69 cases were included in the stand-alone expandable cage group and 150 cases in the control group. The stand-alone group showed shorter operative time (58.48±11.10 versus 81.43±13.75, P=.00028), lower rate of PJK (10.1% versus 22.5%, P=.03), and restoration of local angle (4.66±3.76 versus 2.03±1.16, P=.000079) than the control group. However, sagittal balance (0.01±2.57 versus 0.50 ±2.10, P=.07) was not restored, and weakness showed higher rate of subsidence (16.31% versus 4.85 %, P=.0018), pseudoarthrosis (9.92% versus 2.42%, P=.02), cage, and retropulsion (3.55% versus 0, P=.01) than the control group.Conclusions: Stand-alone expandable cage fusion can restore local lordosis; however, global sagittal balance was not restored. Furthermore, implant safety has not yet been proven.

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Spinopelvic sagittal imbalance is risky for development of proximal instrumented fracture after posterior instrumentation.

10.21203/rs.3.rs-253715/v1 ◽

2021 ◽

Author(s):

Jen-Chung Liao ◽

Wen-Jer Chen

Keyword(s):

Posterior Instrumentation ◽

Control Group ◽

Sacral Slope ◽

Sagittal Imbalance ◽

Study Group ◽

Fracture Type ◽

Mineral Density ◽

Spinopelvic Parameters ◽

T Score ◽

Proximal Junctional Failure

Abstract Backgrounds: Postoperative fracture of the upper instrumented vertebrae (UIV) is thought to be as fracture type of proximal junctional failure (PJF), which usually needs revision surgery for salvage. The purpose of this study was to investigate the influences of spinopelvic parameters, such as the pelvic incidence (PI) angles, sacral slope (SS) angles, and pelvic tilt (PT), sagittal vertical axis (SVA), and proximal local kyphosis (PLK) angle on the development of fracture type of proximal junctional failure after posterior instrumentation. Methods This was a retrospective 1:3 matched case-control cohort study: 24 patients in the study group and 72 patients in the control group. The weighted Charlson Comorbidity Index (CCI) and bone mineral density (BMD) with T score were recorded. In addition to spinopelvic parameters, PI-LL and spinopelvic realignment score were calculated. Results More comorbidities (CCI, p = 0.002), poorer bone density (T score, p = 0.001) were noted in the study group. Before surgery, the study group had significantly lower LL (p = 0.046), SS (p = 0.043), and significantly higher PLK (p < 0.001), PT (p = 0.044) than the control group. Postoperatively, the study group had significantly higher PLK (p < 0.001 ) and lower LL (p = 0.031) than the control group; the degree of PI-LL ( p = 0.007) remained significantly higher in the study group. Both preoperative (p = 0.026) and postoperative (p = 0.045) spinopelvic realignment scores was worse in the study goup. Conclusions Preoperative and postoperative lower LL/spinopelvic realignment score, and higher PLK/PI-LL were significantly associated with instrumented fracture at upper instrumented vertebrae. An appropriate LL and a lower PLK should be obtained at surgery to prevent the development of instrumented fracture.

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