T1 Spinopelvic Inclination Research Articles

Anterior Column Realignment (ACR) for Focal Kyphotic Spinal Deformity Using a Lateral Transpsoas Approach and ALL Release

Retrospective case series. Introduce and evaluate the safety of a new technique of anterior column realignment (ACR) using a lateral transpsoas approach with release of anterior longitudinal ligament and annulus for correction of focal kyphotic deformity. Spinal sagittal imbalance can adversely affect the long-term outcomes of patients with spinal deformity. Clinical and radiographic review of patients who underwent ACR. Seventeen consecutive patients (12 females; 5 males) with a mean age of 63 years (range, 35-76 y) and a mean follow-up of 24 months (range, 12-82 mo) were identified. Fourteen of 17 (82%) had previous spine surgery and 12/17 (71%) had previous fusion. Twelve of the 17 (71%) underwent ACR for adjacent segment disease. Fifteen patients (88%) had Smith-Petersen osteotomies at the ACR level.The mean motion segment angle was 9 degrees preoperatively, which corrected to -19 degrees after ACR and to -26 degrees after posterior instrumentation. Motion segment angle was maintained at -23 degrees at the latest follow-up. The mean lumbar lordosis was -16 degrees preoperatively, which improved to -38 degrees after ACR and to -45 degrees after posterior instrumentation. Lumbar lordosis was maintained at -51 degrees at the latest follow-up. Pelvic tilt averaged 34 degrees before ACR and improved to 24 degrees after ACR and posterior instrumentation and maintained at 25 degrees at the latest follow-up. Patients with preoperative negative T1 spinopelvic inclination (T1SPI) corrected from -6 to -2 degrees and those with 0 or positive T1SPI corrected from 5 to -3 degrees after ACR at the latest follow-up.Eight patients (47%) had 10 complications. Four complications occurred after ACR. Two of 4 were neurological (1 persistent weakness) and 1 was vascular injury during anterior plate removal. Compared with posterior-based techniques, our preliminary results of ACR showed similar correction capacity and similar rate of morbidities for the treatment of focal kyphotic spinal deformity. Careful case selection, attention to the details of the technique, and enough experience are prudent elements for a desirable outcome.

Prise en charge chirurgicale de 379 cas de canal lombaire étroit

Patients with degenerative lumbar stenosis (DLS) adopt a forward flexed posture in an attempt to decompress neural elements. The relationship between sagittal alignment and severity of lumbar stenosis has not previously been studied.We hypothesized that patients with increasing radiological severity of lumbar stenosis will exhibit worsening sagittal alignment.This is a cross-sectional study.Our sample consists of patients who have DLS.Standing pelvic, regional, lower extremity and global sagittal alignment, and health-related quality of life (HRQoL) were the outcome measures.Patients with DLS were identified from a retrospective clinical database with corresponding full-body stereoradiographs. Exclusion criteria included coronal malalignment, prior spine surgery, spondylolisthesis>Grade 1, non-degenerative spinal pathology, or skeletal immaturity. Central stenosis severity was graded on axial T2-weighted magnetic resonance imaging (MRI) from L1–S1. Foraminal stenosis and supine lordosis was graded on sagittal T1-weighted images. Standing pelvic, regional, lower extremity, and global sagittal alignment were measured using validated software. The HRQoL measures were also analyzed in relation to severity of stenosis.A total of 125 patients were identified with DLS on appropriate imaging. As central stenosis grade increased, patients displayed significantly increasing standing T1 pelvic angle, pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis (p<.05). No significant difference wasfound in pelvic incidence, supine lordosis, thoracic kyphosis, or T1 spinopelvic inclination between central stenosis groups. Despite similar supine lordosis between stenosis groups, patients with Grades 2 and 3 stenosis had less standing lordosis, suggesting antalgic posturing. Upper lumbar (L1–L3) stenosis predicted worse alignment than lower lumbar (L4–S1) stenosis.Increasing severity of foraminal stenosis was associated with reduced lumbar lordosis; however, no significant postural difference in lordosis, thoracolumbar, or lower extremity compensatory mechanisms were noted between foraminal stenosis groups. Stenosis grading did not predict worsening HRQoLs in central or foraminal stenosis.Severity of central lumbar stenosis as graded on MRI correlates with severity of sagittal malalignment. These findings support theories of sagittal malalignment as a compensatory mechanism for central lumbar stenosis.

Pelvic tilt and trunk inclination: new predictive factors in curve progression during the Milwaukee bracing for adolescent idiopathic scoliosis

Previous studies had shown that sagittal spinal and pelvic morphology may be associated with the development and progression of adolescent idiopathic scoliosis, but the predictive value of initial spinal and pelvic morphology on the curve progression during brace treatment is unknown. The objective of this study was to evaluate the relation between initial spinopelvic morphology and the risk of curve progression of adolescent idiopathic scoliosis with the Milwaukee brace. From 2002 to 2007, adolescent idiopathic scoliosis (single thoracic curve with apex at or above T8) was treated with the Milwaukee brace in 60 girls. Initial standing, full-length lateral radiographs were made and seven sagittal radiographic parameters of spinal and pelvic alignment were measured. Patients were followed until skeletal maturity or progression of Cobb angle >45°. The progression of curve was defined as an increase of Cobb angle ≥6° at final follow-up or progression to surgery during brace treatment. The 45 patients (75.0 %) who had successful control of curve progression were initially significantly more skeletally mature (higher mean Risser sign) than the 15 patients (25.0 %) who had curve progression. The initial mean Cobb angle was similar between the stable and progressed groups. The mean pelvic tilt, T1-spinopelvic inclination and T9-spinopelvic inclination angles were significantly greater in the stable group than in the progressed group and these three angles were independent predictors for curve progression during brace treatment. There were no significant differences between the stable and progressed groups in initial mean pelvic incidence, sacral slope, thoracic kyphosis or lumbar lordosis angles. Pre-bracing pelvic tilt ≤-0.5° was strongly predictive and T1-spinopelvic inclination ≤3.5° was moderately predictive of curve progression during the Milwaukee brace treatment. Initial pelvic tilt and spinopelvic inclination angles may predict the curve progression and treatment outcome of adolescent idiopathic scoliosis with the Milwaukee brace.

Effect of Spino-Pelvic Sagittal Balance on Degree of Disk Degeneration in the Lumbar Spine

Introduction Recent studies have focused on spino-pelvic sagittal balance. Changes in sagittal balance could alter the load on the spine and may affect spinal mobility. Increasing recognition of the clinical impacted that sagittal alignment has on back pain and adjacent segment degeneration. But recent studies focused only on the effects of lumbar sagittal alignment to the disk degeneration. The relationship between spino-pelvic sagittal balance and lumbar disk degeneration has yet to be determined. The objective of this research was to study the effect of spino-pelvic sagittal balance on degree of disk degeneration in the lumbar spine. Materials and Methods The lumbar spine magnetic resonance imaging (MRI) and whole spine X-ray of 32 patients (13 males and 19 females) with a mean age of 57.92 years (range: 25 to 84 years) were retrospectively evaluated. Patients with history of prior spinal surgery, serious congenital anomalies, infection, spinal trauma, tumorn or ankylosing spondylitis were excluded from the study. In every patient, spino-pelvic sagittal parameters such as sagittal vertical axis (SVA), thoracic Kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), C7 tilt (C7T), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), spino-sacral angle (SSA), spino-pelvic angle (SPA), T1 spiono-pelvic inclination (T1-SPI), and T9 spino-pelvic inclination (T9-SPI) were measured in the whole spine X-ray to evaluate the sagittal balance. And lumbar intervertebral disk degeneration grade for each level (L1/2, L2/3, L3/4, L4/5 and L5/S1) was assessed using the lumbar MRI according to the Pfirrmann grading. The relationship between sagittal parameters and disk degeneration grade was analyzed. Results There was significant correlation between SVA and disk degeneration grade in level L5/S1 ( r = 0.565, p = 0.003) but not significant correlation in level L1/2, L2/3, L3/4 or L4/5. Similarly, significant correlation has been determined between C7T and degree of disk degeneration at the level of L5/S1 ( r = 0.557, p = 0.004), between PT and L2/3 ( r = 0.519, p = 0.008), between SSA and L5/S1 ( r = 0.466, p = 0.019), between SPA and L2/3 ( r = 0.466, p = 0.019), and between T1-SPI and L5/S1 ( r = 0.398, p = 0.049). No significant effect was detected for the degree of disk degeneration with the changes in spino-pelvic parameters like TK, TLK, LL, PI, SS, and T9-SPI. Conclusion Spino-pelvic parameters such as SVA, C7T, SSA, and T1-SPI may have effects on the degeneration of L5/S1 disk. And parameters such as SPA and PT may have effects on the degeneration of L2/3 disk. Changes in spino-pelvic parameters may influence the degree of disk degeneration, but all the parameters are not equally involved in the degree of disk degeneration. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared

Changes in Thoracic Kyphosis Negatively Impact Sagittal Alignment After Lumbar Pedicle Subtraction Osteotomy

Consecutive, multicenter retrospective review. To evaluate if change in thoracic kyphosis (TK) has a positive or negative impact on spinopelvic alignment after lumbar pedicle subtraction osteotomy (PSO) with short fusions. In the setting of sagittal malalignment, the effect of large vertebral resections can now be anticipated in long fusions, but their impact on unfused segments (reciprocal changes [RC]) remains poorly understood. A total of 34 adult patients (mean age = 54 years; SD = 12) who underwent lumbar PSO with upper instrumented vertebra below T10 were included. Radiographic analysis included pre- and postassessment of TK, lumbar lordosis (LL), sagittal vertical axis (SVA), T1 spinopelvic inclination (T1SPI), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were analyzed to determine successful realignment. RC in the thoracic spine was designated favorable or unfavorable on the basis of impact on final SVA and PT. Mean PSO resection was 26°. LL increased from 20° to 49° (P < 0.001). SVA improved from 14 to 4 cm (P < 0.001), and PT improved from 33° to 25° (P < 0.001). Mean increase in TK was 13° (P = 0.002) but was unchanged in 11 patients. Five patients had a favorable RC, and 18 patients had an unfavorable RC. Unfavorable RC was attributed to junctional failure in 6 of 18 patients. Significant differences in the unfavorable RC group included age and greater preoperative PT, PI, SVA, and T1SPI. Significant postoperative alignment changes can occur through unfused thoracic spinal segments after lumbar PSO. Unfavorable RC may limit optimal correction and lead to clinical failures. Risk factors for unfavorable thoracic RC include older patients, larger preoperative PI and PT, and worse preoperative T1SPI and are not simply due to junctional failure. Care should be taken with selective lumbar fusion and PSO in older patients and in those with severe preoperative spinopelvic parameters.

Pelvic Tilt and Truncal Inclination

Prospective radiographic and clinical analysis. Investigate the relationship between spino-pelvic parameters and patient self reported outcomes on adult subjects with spinal deformities. It is becoming increasingly recognized that the study of spinal alignment should include pelvic position. While pelvic incidence determines lumbar lordosis, pelvic tilt (PT) is a positional parameter reflecting compensation to spinal deformity. Correlation between plumbline offset (sagittal vertical axis [SVA]) and Health Related Quality of Life (HRQOL) measures has been demonstrated, but such a study is lacking for PT. This prospective study was carried out on 125 adult patients suffering from spinal deformity (mean age: 57 years). Full-length free-standing radiographs including the spine and pelvis were available for all patients. HRQOL instruments included: Oswestry Disability Index, Short Form-12, Scoliosis Research Society. Correlation analysis between radiographic spinopelvic parameters and HRQOL measures was pursued. Correlation analysis revealed no significance pertaining to coronal plane parameters. Significant sagittal plane correlations were identified. SVA and truncal inclination measured by T1 spinopelvic inclination (T1-SPI) (angle between T1-hip axis and vertical) correlated with: Scoliosis Research Society (appearance, activity, total score), Oswestry Disability Index, and Short Form-12 (physical component score). Correlation coefficients ranged from 0.42 < r < 0.55 (P < 0.0001). T1-SPI revealed greater correlation with HRQOL compared to SVA. PT showed correlation with HRQOL (0.28 < r < 0.42) and with SVA (r = 0.64, P < 0.0001). This study confirms that pelvic position measured via PT correlates with HRQOL in the setting of adult deformity. High values of PT express compensatory pelvic retroversion for sagittal spinal malalignment. This study also demonstrates significant T1-SPI correlation with HRQOL measures and outperforms SVA. This parameter carries the advantage of being an angular measurement which avoids the error inherent in measuring offsets in noncalibrated radiographs.