Assessment of Pelvic Incidence Angle in Normal Indian Population and Spondylolisthesis

There is increasing emphasis on the sagittal spino-pelvic alignment and its interpretation is of critical importance in the management of spinal disorders. The vertebral column shows a vital role in the funding and locomotion of the human body. The judgment of normality can be made possible by analyzing the normal patterns of sagittal curvature and characteristics of each pattern of sagittal curvatures. In our study the control group which comprised of 50 healthy volunteers exhibited a minimum pelvic incidence of 33° and a maximum of 60° with an average of 50.12°. The minimum pelvic incidence in the study group was 42° and the maximum was 75°.The average pelvic incidence in the low grade listhesis group was 57.78° and in the high grade listhesis group it was 64.75°.The combined average of pelvic incidence angle in the study group was 58.34°and only one patient had a Pelvic incidence Angle of 75 degrees and the remaining three were only one patient had a Pelvic incidence Angle of 75 degrees and the remaining three were below 65 degrees. The objective of this study is to observe the parameters of sagittal and spino-pelvic balance in a sample of the Indian population consisting of volunteer asymptomatic individuals.

Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes

OBJECTIVE This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Predictive models were created that can be used with high reliability to help distinguish between severe symptomatic DJK and mild asymptomatic DJK through the use of surgical factors, radiographic parameters, and patient variables. METHODS Patients with cervical deformity (CD) were stratified into asymptomatic and symptomatic DJK groups. Symptomatic: 1) DJK angle (DJKA) > 10° and either reoperation due to DJK or > 1 new-onset neurological sequela related to DJK; or 2) either a DJKA > 20° or ∆DJKA > 20°. Asymptomatic: ∆DJK > 10° in the absence of neurological sequelae. Stepwise logistic regressions were used to identify factors associated with these types of DJK. Decision tree analysis established cutoffs. RESULTS A total of 99 patients with CD were included, with 32.2% developing DJK (34.3% asymptomatic, 65.7% symptomatic). A total of 37.5% of asymptomatic patients received a reoperation versus 62.5% symptomatic patients. Multivariate analysis identified independent baseline factors for developing symptomatic DJK as follows: pelvic incidence (OR 1.02); preoperative cervical flexibility (OR 1.04); and combined approach (OR 6.2). Having abnormal hyperkyphosis in the thoracic spine, more so than abnormal cervical lordosis, was a factor for developing symptomatic disease when analyzed against asymptomatic patients (OR 1.2). Predictive modeling identified factors that were predictive of symptomatic versus no DJK, as follows: myelopathy (modified Japanese Orthopaedic Association score 12–14); combined approach; uppermost instrumented vertebra C3 or C4; preoperative hypermobility; and > 7 levels fused (area under the curve 0.89). A predictive model for symptomatic versus asymptomatic disease (area under the curve 0.85) included being frail, T1 slope minus cervical lordosis > 20°, and a pelvic incidence > 46.3°. Controlling for baseline deformity and disability, symptomatic patients had a greater cervical sagittal vertical axis (4–8 cm: 47.6% vs 27%) and were more malaligned according to their Scoliosis Research Society sagittal vertical axis measurement (OR 0.1) than patients without DJK at 1 year (all p < 0.05). Despite their symptomatology and higher reoperation rate, outcomes equilibrated in the symptomatic cohort at 1 year following revision. CONCLUSIONS Overall, 32.2% of patients with CD suffered from DJK. Symptomatic DJK can be predicted with high reliability. It can be further distinguished from asymptomatic occurrences by taking into account pelvic incidence and baseline cervicothoracic deformity severity.

Spinopelvic alignment and lumbar vertebral shape in children: associations with structural spinal abnormalities and body composition in the generation R study

Purpose To investigate the spinopelvic alignment and vertebral shape in children, and associations with body composition and structural spinal abnormalities on magnetic resonance imaging (MRI). Methods We performed a cross-sectional study embedded in the Generation R Study, a prospective population-based birth cohort. Pelvic incidence and vertebral concavity ratios for each lumbar level were determined on sagittal MRI images in 9-year-old children, and structural spinal abnormalities were scored semi-quantitatively. The BMI-SD score was calculated, and body composition was assessed using DXA scans. Associations of pelvic incidence and vertebral concavity ratios with structural abnormalities and body composition measures were assessed using (multilevel) regression analyses. Results This study included 522 participants (47.7% boys), aged 9.9 years (IQR 9.7–10.0). The mean pelvic incidence was 36.6° (SD 8.0). Vertebral concavity ratios ranged from 0.87 to 0.90, with significantly lower ratios for boys compared to girls. Associations were found for a larger pelvic incidence with decreased disc height [OR 1.03 (95% CI 1.02–1.05)], and a pelvic incidence in the lowest tertile with less disc bulging [OR 0.73 (95% CI 0.56–0.95)]. Increased vertebral concavity ratio was associated with decreased disc height [OR 14.16 (95% CI 1.28–157.13)]. Finally, increased fat-free mass index was associated with a smaller pelvic incidence [adjusted OR 0.85 (95% CI 0.07–1.63)]. Conclusion The mean pelvic incidence of 9-year-old children is 36.6° on supine MRI images, and a slightly concave shape of the lumbar vertebrae is seen. Spinopelvic alignment is associated with structural spinal abnormalities, and might itself be influenced by the children’s body composition.

Stress Analysis of the Lower Lumbar Spine Three-joint Complex According to Different Pelvic Incidences

Background: Pelvic incidence is closely related to degeneration of the facet joint and intervertebral disc and is related to the orientation of the facet joints. Currently, very few studies have been conducted on the force analysis of the three-joint complex in patients with different pelvic incidence measurements under different sports postures. We designed this study to better assess the influence of pelvic incidence on the stress of the lumbar three-joint complex. Finite element analysis can provide a biomechanical basis for the relationship between different pelvic incidences and degenerative diseases of the lower lumbar spine.Methods: We developed three nonlinear finite element models of the lumbar spine (L1-S1) with different pelvic incidences (27.44°, 47.05°, and 62.28°) and validated them to study the biomechanical response of facet joints and intervertebral discs with a follower preload of 400 N, under different torques (5 Nm, 10 Nm, and 15 Nm), and compared the stress of the three-joint complex of the lower lumbar spine (L3-S1) in different positions (flexion-extension, left-right bending, and left-right torsion).Results: In the flexion position, the stress of the disc in the low pelvic incidence model was the largest among the three models; the stress of the facet joint in the high pelvic incidence model was the largest among the three groups during the extension position. During torsion, the intradiscal pressure of the high pelvic incidence model was higher than that of the other two models in the L3/4 segment, and the maximum von Mises stress of the annulus fibrosus in the L5/S1 segment with a large pelvic incidence was greater than that of the other two models.Conclusions: Pelvic incidence is related to the occurrence and development of degenerative lumbar diseases. The stress of the lower lumbar facet joints and fibrous annulus of individuals with a high pelvic incidence is greater than that of individuals with a low pelvic incidence or a normal pelvic incidence. Although this condition only occurs in individual segments, to a certain extent, it can also reflect the influence of pelvic incidence on the force of the three-joint complex of the lower lumbar spine.

Complications of Surgical Treatment of Adult Scoliosis

Introduction: With the increase in global life expectancy, the number of patients presenting with progressive spinal deformities is also on rise. The increasing frequency of surgical intervention as a treatment of this group of patients is associated with many complications and also with increasing rate of reoperation. Methodology: Seventy-two cases of adult scoliosis were treated surgically in Ain Shams spine unit with a minimum follow-up of five years (average, 76 months). Preoperative clinical and radiological evaluation was done, with special emphasis on the degree of pains (back and leg), Oswestry Disability Index (ODI), scoliosis angle, lumbar lordosis, any instability, and the level of spinal canal stenosis needing decompression. The pelvic incidence was measured preoperatively to plan the amount of lordosis needed to be restored. Result: The mean preoperative scoliosis angle was 22 ± 10.4º (16 to 34º) and the mean preoperative lordosis angle was 20.3 ± 12.7º (–15 to –28º). The mean preoperative ODI score was 54.7 ± 5.5, and the mean postoperative scoliosis angle improved to 7.4 ± 3.3. The mean postoperative lordosis angle became 37.3 ± 8.6, and the mean postoperative ODI score was 21.3 ± 3.8. Conclusion: The list of complications included seven cases of pseudoarthrosis and screw loosening, adjacent segment fracture in nine cases, and one case of spondylodiscitis at a level just proximal to the fused level. These 17 cases needed reoperations (24%). Additionally, there were five cases of dural tear, prolonged graft side pain in one case, and two cases of superficial wound infections.