Can the Relationship between Pelvic Incidence, Pelvic Tilt and Sacral Slope be Affected by Changing Pelvic Position?

Background: Acetabular retroversion may lead to impingement and pain, which can be treated with an anteverting periacetabular osteotomy (aPAO). Pelvic tilt influences acetabular orientation; as pelvic tilt angle reduces, acetabular version reduces. Thus, acetabular retroversion may be a deformity secondary to abnormal pelvic tilt (functional retroversion) or an anatomic deformity of the acetabulum and the innominate bone (pelvic ring). Purpose: To (1) measure the spinopelvic morphology in patients with acetabular retroversion and (2) assess whether pelvic tilt changes after successful anteverting PAO (aPAO), thus testing whether preoperative pelvic tilt was compensatory. Study Design: Case series; Level of evidence, 4. Methods: A consecutive cohort of 48 hips (42 patients; 30 ± 7 years [mean ± SD]) with acetabular retroversion that underwent successful aPAO was studied. Spinopelvic morphology (pelvic tilt, pelvic incidence, anterior pelvic plane, and sacral slope) was measured from computed tomography scans including the sacral end plate in 21 patients, with adequate images. In addition, the change in pelvic tilt with aPAO was measured via the sacrofemoral-pubic angle with supine pelvic radiographs at an interval of 2.5 ± 2 years. Results: The spinopelvic characteristics included a pelvic tilt of 4° ± 4°, a sacral slope of 39° ± 9°, an anterior pelvic plane angle of 11° ± 5°, and a pelvic incidence of 42° ± 10°. Preoperative pelvic tilt was 4° ± 4° and did not change postoperatively (4° ± 4°) ( P = .676). Conclusion: Pelvic tilt in acetabular retroversion was within normal parameters, illustrating “normal” sagittal pelvic balance and values similar to those reported in the literature in healthy subjects. In addition, it did not change after aPAO. Thus, acetabular retroversion was not secondary to a maladaptive pelvic tilt (functional retroversion). Further work is required to assess whether retroversion is a reflection of a pelvic morphological abnormality rather than an isolated acetabular abnormality. Treatment of acetabular retroversion should focus on correcting the deformity rather than attempting to change the functional pelvic position.

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3D simulation of radiographic projections to test and reduce the effect of pelvic tilt on the accuracy of cross-table lateral radiography

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03858-2 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Jie Xu ◽

Baohua Su ◽

Wenhui Zhang ◽

Hao Sun ◽

Deng Li ◽

...

Keyword(s):

Measurement Errors ◽

Pelvic Tilt ◽

Intra Class Correlation ◽

High Agreement ◽

Mathematical Algorithm ◽

Radiographic Measurements ◽

Pelvic Position ◽

The Relationship ◽

Intra Class Correlation Coefficient ◽

Version Measurement

Abstract Background Cross-table lateral (CL) radiography is a convenient and feasible method to assess cup version angle (VA) after total hip arthroplasty; However, pelvic tilt (PT) may contribute to its measurement inaccuracy. How PT affects CL radiographic measurements have not been well studied. We sought (1) to determine the effect of the PT on cup version measurement on CL radiography and (2) to develop a method for reducing measurement errors caused by the PT. Methods We used 3D technique to construct standard model and capture CL radiography simulation. A linear regression model was created to analyze the relationship between PT and VA. CL radiography and computed tomography (CT) were performed for the enrolled patients after surgery. The consistency between CL and CT measurements were verified by intra-class correlation coefficient (ICC). Results There was a high correlation between the VA and PT. For each 1-degree increased in the PT, the VA decreased by 0.76° (R2 = 0.995, p < 0.001). Based on the data, we created a corrective formula to convert the radiographic measurements into values approximating the actual VA under a natural pelvic position. The VA measurements corrected by our equation was in high agreement with the CT-measured values with reference to the corresponding PT (ICC = 0.988, p < 0.001), which was in sharp contrast to that without PT control (ICC = 0.454, p = 0.203). Conclusions The PT may contribute to cup version measurement inaccuracies on CL radiography. Our mathematical algorithm can serve as a reliable method to improve the accuracy of CL radiography.

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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/v1 ◽

2019 ◽

Author(s):

Diyu Song ◽

Guoquan Zheng ◽

Tianhao Wang ◽

Dengbin Qi ◽

Yan Wang

Keyword(s):

Ankylosing Spondylitis ◽

Pelvic Incidence ◽

Vertical Axis ◽

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 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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3D simulation of radiographic projections to test and reduce the effect of pelvic tilt on the accuracy of cross-table lateral radiography

10.21203/rs.3.rs-39670/v2 ◽

2020 ◽

Author(s):

Jie Xu ◽

Baohua Su ◽

Wenhui Zhang ◽

Hao Sun ◽

Deng Li ◽

...

Keyword(s):

Measurement Errors ◽

Pelvic Tilt ◽

Intra Class Correlation ◽

High Agreement ◽

Mathematical Algorithm ◽

Radiographic Measurements ◽

Pelvic Position ◽

The Relationship ◽

Intra Class Correlation Coefficient ◽

Version Measurement

Abstract Background: Cross-table lateral (CL) radiography is a convenient and feasible method to assess cup version angle (VA) after total hip arthroplasty; However, pelvic tilt (PT) may contribute to its measurement inaccuracy. How PT affects CL radiographic measurements have not been well studied. We sought (1) to determine the effect of the PT on cup version measurement on CL radiography and (2) to develop a method for reducing measurement errors caused by the PT. Methods: We used 3D technique to construct standard model and capture CL radiography simulation. A linear regression model was created to analyze the relationship between PT and VA. CL radiography and computed tomography (CT) were performed for the enrolled patients after surgery. The consistency between CL and CT measurements were verified by intra-class correlation coefficient (ICC). Results: There was a high correlation between the VA and PT. For each 1-degree increased in the PT, the VA decreased by 0.76° (R²=0.995, p<0.001). Based on the data, we created a corrective formula to convert the radiographic measurements into values approximating the actual VA under a natural pelvic position. The VA measurements corrected by our equation was in high agreement with the CT-measured values with reference to the corresponding PT (ICC=0.988, p<0.001), which was in sharp contrast to that without PT control (ICC=0.454, p=0.203). Conclusions: The PT may contribute to cup version measurement inaccuracies on CL radiography. Our mathematical algorithm can serve as a reliable method to improve the accuracy of CL radiography.

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ASSOCIATION OF SPINOPELVIC PARAMETERS WITH THE LOCATION OF LUMBAR DISC HERNIATION

Coluna/Columna ◽

10.1590/s1808-185120151403145172 ◽

2015 ◽

Vol 14 (3) ◽

pp. 205-209

Author(s):

Jefferson Coelho de Léo ◽

Álvaro Coelho de Léo ◽

Igor Machado Cardoso ◽

Charbel Jacob Júnior ◽

José Lucas Batista Júnior

Keyword(s):

Lumbar Disc Herniation ◽

Disc Herniation ◽

Lumbar Lordosis ◽

Pelvic Tilt ◽

Pelvic Incidence ◽

Lumbar Disc ◽

Sacral Slope ◽

Spinopelvic Parameters ◽

Lateral Recess ◽

Central Disc

Objective:To associate spinopelvic parameters, pelvic incidence, sacral slope, pelvic tilt and lumbar lordosis with the axial location of lumbar disc herniation.Methods:Retrospective study, which evaluated imaging and medical records of 61 patients with lumbar disc herniation, who underwent surgery with decompression and instrumented lumbar fusion in only one level. Pelvic incidence, sacral slope, pelvic tilt and lumbar lordosis with simple lumbopelvic lateral radiographs, which included the lumbar spine, the sacrum and the proximal femur. The affected segment was identified as the level and location of lumbar disc herniation in the axial plane with MRI scans.Results:Of 61 patients, 29 (47.5%) had low lumbar lordosis; in this group 24 (82.8%) had central disc herniation, 4 (13.8%) had lateral recess disc herniation and 1 (3.4%) had extraforaminal disc herniation (p<0.05). Of the 61 patients, 18 (29.5%) had low sacral slope; of this group 15 (83.3%) had central disc herniation and 3 (16.7%) had disc herniation in lateral recess (p<0.05).Conclusions:There is a trend towards greater load distribution in the anterior region of the spine when the spine has hypolordotic curve. This study found an association between low lordosis and central disc herniation, as well as low sacral slope and central disc herniation.

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The effect of direct vertebral rotation on the spine parameters (coronal and sagittal) in adolescent idiopathic scoliosis

Journal of Back and Musculoskeletal Rehabilitation ◽

10.3233/bmr-200320 ◽

2021 ◽

pp. 1-8

Author(s):

Carlos Eduardo Gonçales Barsotti ◽

Carlos Augusto Belchior B. Junior ◽

Rodrigo Mantelatto Andrade ◽

Alexandre Penna Torini ◽

Ana Paula Ribeiro

Keyword(s):

Idiopathic Scoliosis ◽

Cobb Angle ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Pelvic Tilt ◽

Pelvic Incidence ◽

Vertebral Rotation ◽

Sacral Slope ◽

Post Surgery ◽

Radiographic Parameters

BACKGROUND: Idiopathic scoliosis is accompanied by postural alterations, instability of gait, and functional disabilities. The objective was to verify radiographic parameters (coronal and sagittal) of adolescents with idiopathic scoliosis (AIS) pre- and post-surgery with direct vertebral rotation (DVR), associated with type 1 osteotomies in all segments (except the most proximal) and type 2 in the periapical vertebrae of the curves. METHODS: A prospective study design was employed in which 41 AIS were evaluated and compared pre- and post-surgery. Scoliosis was confirmed by a spine X-ray exam (Cobb angle). Eight radiographic parameters were measured: Cobb angles (thoracic proximal and distal), segmental kyphosis, total kyphosis, lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt. RESULTS: The Cobb angle averaged 51.3∘± 14.9∘. Post-surgery, there were significant reductions for the following spine measurement parameters: Cobb angle thoracic proximal (p= 0.003); Cobb angle thoracic distal (p= 0.001); Cobb angle lumbar (p= 0.001); kyphosis (T5-T12, p= 0.012); and kyphosis (T1-T12, p= 0.002). These reductions showed the effectiveness of surgical correction to reduce Cobb angles and improve thoracic kyphosis. The values obtained for lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt were not significantly different pre- and post-surgery. CONCLUSION: The surgical technique of DVR in AIS proved to be effective in the coronal and sagittal parameters directed at Cobb angles and thoracic kyphosis in order to favor the rehabilitation process.

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Synchronous imaging of pelvic geometry and muscle morphometry: a pilot study of pelvic retroversion using upright MRI

Scientific Reports ◽

10.1038/s41598-021-99305-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Noor Shaikh ◽

Honglin Zhang ◽

Stephen H. M. Brown ◽

Hamza Lari ◽

Oliver Lasry ◽

...

Keyword(s):

Pelvic Tilt ◽

Pelvic Incidence ◽

Sacral Slope ◽

Resonance Imaging ◽

Cross Sectional ◽

Future Studies ◽

Upright Mri ◽

Asymptomatic Volunteers ◽

Good Repeatability ◽

Magnetic Resonance Imaging Mri

AbstractThis study investigated feasibility of imaging lumbopelvic musculature and geometry in tandem using upright magnetic resonance imaging (MRI) in asymptomatic adults, and explored the effect of pelvic retroversion on lumbopelvic musculature and geometry. Six asymptomatic volunteers were imaged (0.5 T upright MRI) in 4 postures: standing, standing pelvic retroversion, standing 30° flexion, and supine. Measures included muscle morphometry [cross-sectional area (CSA), circularity, radius, and angle] of the gluteus and iliopsoas, and pelvic geometry [pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), L3–S1 lumbar lordosis (LL)] L3-coccyx. With four volunteers repeating postures, and three raters assessing repeatability, there was generally good repeatability [ICC(3,1) 0.80–0.97]. Retroversion had level dependent effects on muscle measures, for example gluteus CSA and circularity increased (up to 22%). Retroversion increased PT, decreased SS, and decreased L3–S1 LL, but did not affect PI. Gluteus CSA and circularity also had level-specific correlations with PT, SS, and L3–S1 LL. Overall, upright MRI of the lumbopelvic musculature is feasible with good reproducibility, and the morphometry of the involved muscles significantly changes with posture. This finding has the potential to be used for clinical consideration in designing and performing future studies with greater number of healthy subjects and patients.

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Postlaminectomy lumbopelvic sagittal changes in patients with developmental lumbar spinal stenosis grouped into Roussouly lumbopelvic sagittal profiles: 2- to 10-year prospective follow-up

Journal of Neurosurgery Spine ◽

10.3171/2021.8.spine21797 ◽

2021 ◽

pp. 1-9

Author(s):

Sameer A. Kitab ◽

Andrew E. Wakefield ◽

Edward C. Benzel

Keyword(s):

Spinal Stenosis ◽

Pelvic Tilt ◽

Pelvic Incidence ◽

Sacral Slope ◽

Compensatory Mechanisms ◽

Lumbar Segment ◽

Lumbar Spinal

OBJECTIVE Roussouly lumbopelvic sagittal profiles are associated with distinct pathologies or distinct natural histories and prognoses. The associations between developmental lumbar spinal stenosis (DLSS) and native lumbopelvic sagittal profiles are unknown. Moreover, the relative effects of multilevel decompression on lumbar sagittal alignment, geometrical parameters of the pelvis, and compensatory mechanisms for each of the Roussouly subtypes are unknown. This study aimed to explore the association between DLSS and native lumbar lordosis (LL) subtypes. It also attempts to understand the natural history of postlaminectomy lumbopelvic sagittal changes and compensatory mechanisms for each of the Roussouly subtypes and to define the critical lumbar segment or specific lordosis arc that is recruited after relief of the stenosis effect. METHODS A total of 418 patients with multilevel DLSS were grouped into various Roussouly subtypes, and lumbopelvic sagittal parameters were prospectively compared at follow-up intervals of preoperative to < 2 years, 2 to < 5 years, and 5 to ≥ 10 years after laminectomy. The variables analyzed included LL, upper lordosis arc from L1 to L4, lower lordosis arc from L4 to S1, and segmental lordosis from L1 to S1. Pelvic parameters included pelvic incidence, sacral slope, pelvic tilt, and pelvic incidence minus LL values. RESULTS Of the 329 patients who were followed up throughout this study, 33.7% had Roussouly type 1 native lordosis, whereas the incidence rates of types 2, 3, and 4 were 33.4%, 21.9%, and 10.9%, respectively. LL was not reduced in any of the Roussouly subtypes after multilevel decompressions. Instead, LL increased by 4.5° (SD 11.9°—from 27.3° [SD 11.5°] to 31.8° [SD 9.8°]) in Roussouly type 1 and by 3.1° (SD 11.6°—from 41.3° [SD 9.5°] to 44.4° [SD = 9.7°]) in Roussouly type 2. The other Roussouly types showed no significant changes. Pelvic tilt decreased significantly—by 2.8°, whereas sacral slope increased significantly—by 2.9° in Roussouly type 1 and by 1.7° in Roussouly type 2. The critical lumbar segment that recruits LL differs between Roussouly subtypes. Increments and changes were sustained until the final follow-up. CONCLUSIONS The study findings are important in predicting patient prognosis, LL evolution, and the need for prophylactic or corrective deformity surgery. Multilevel involvement in DLSS and the high prevalence of Roussouly types 1 and 2 suggest that spinal canal dimensions are closely linked to the developmental evolution of LL.

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