Purpose
To describe normal variations in sagittal spinal radiographic parameters over an interval period and establish physiological norms and guidelines for which these images should be interpreted.Methods
Data were prospectively collected from a continuous series of adult patients with first-episode mild low back pain presenting to a single institution. The sagittal parameters of two serial radiographic images taken 6-months apart were obtained with the EOS® slot scanner. Measured parameters include CL, TK, TL, LL, PI, PT, SS, and end and apical vertebrae. Chi-squared test and Wilcoxon Signed Rank test were used to compare categorical and continuous variables, respectively.Results
Sixty patients with a total of 120 whole-body sagittal X-rays were analysed. Mean age was 52.1 years (SD 21.2). Mean interval between the first and second X-rays was 126.2 days (SD 47.2). Small variations (< 1°) occur for all except PT (1.2°), CL (1.2°), and SVA (2.9 cm). Pelvic tilt showed significant difference between two images (p = 0.035). Subgroup analysis based on the time interval between X-rays, and between the first and second X-rays, did not show significant differences. Consistent findings were found for end and apical vertebrae of the thoracic and lumbar spine between the first and second X-rays for sagittal curve shapes.Conclusions
Radiographic sagittal parameters vary between serial images and reflect dynamism in spinal balancing. SVA and PT are predisposed to the widest variation. SVA has the largest variation between individuals of low pelvic tilt. Therefore, interpretation of these parameters should be patient specific and relies on trends rather than a one-time assessment.Background Context
Adult spinal deformity correction sometimes involves long posterior pedicle screw constructs extending from the lumbosacral spine to the thoracic vertebra. As fusion obliterates motion and places supraphysiological stress on adjacent spinal segments, it is crucial to ascertain the ideal upper instrumented vertebra (UIV) to minimize risk of proximal junctional failure (PJF). The T10 vertebra is often chosen to allow bridging of the thoracolumbar junction into the immobile thoracic vertebrae on the basis that it is the lowest immobile thoracic vertebra strut by the rib cage.Purpose
This study aimed to characterize the range of motion (ROM) of each vertebral segment from T7 to S1 to determine if T10 is truly the lowest immobile thoracic vertebra.Study Design/Setting
This is a prospective, comparative study.Patient Sample
Seventy-nine adults (mean age of 45.4 years) presenting with low back pain or lower limb radiculopathy or both, without previous spinal intervention, metastases, fractures, infection, or congenital deformities of the spine, were included in the study.Outcome Measures
A ROM >5° across two vertebral segments as determined by the Cobb method from radiographs.Methods
Lumbar flexion-extension and neutral erect radiographs were obtained in randomized order using a slot scanner. Segmental ROM was measured from T7–T8 to L5–S1 and analyzed for significant differences using t tests. Age, gender, radiographical indices such as standard spinopelvic parameters, sagittal vertical axis (SVA), C7–T12 SVA, T1 slope, thoracic kyphosis (TK), and lumbar lordosis (LL) were studied via multivariate analysis to identify predictive factors for >5° change in ROM at the various segmental levels. There were no sources of funding and no conflicts of interest associated with this study.Results
In the thoracolumbar spine, significant decreases in ROM when compared with the adjacent caudad segment occurs up to T9–T10, with mean total ROM of 1.98±1.47° (p<.001) seen in T9–T10, 2.19±1.67° (p<.001) in T10–T11, and 3.92±3.21°(p<.001) in T11–T12. The total ROM of T8–T9 (2.53±1.79°) was not significantly different from that of T9–T10 (p=.261). At the thoracolumbar junction, absence of scoliosis (OR 11.37, p=.020), high pelvic incidence (OR 1.14, p=.046), and low T1 slope (OR 1.45, p=.030) were predictive of ROM >5°.Conclusions
Lumbar spine flexion-extension ROM decreases as it approaches the thoracolumbar junction. T10 is indeed the lowest immobile thoracic vertebra strut by the rib cage, and the last significant decrease in ROM is observed at T9–T10, in relation to T10–T11. However, because this also implies that a UIV of T10 would mean there is only one level of fixation above the relatively mobile segment, while respecting other factors that influence UIV selection, we propose the T9 vertebra as a more ideal UIV to fulfill the biomechanical concept of bridge fixation. However, this decision should still be taken on a case-by-case basis. 相似文献Background Context
Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans.Purpose
This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS.Study Design/Setting
This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period).Patient Sample
All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study.Outcome Measures
Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures.Methods
All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables.Results
The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11–20). Between the two lateral X-rays, there was a mean difference of 0.79?cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77?cm (p=.002), 0.79° (p=.009), and 1.49° (p=.001) mean difference in SVA, LL, and PT, respectively. Additionally, there was also a 1.85° (p=.009) and 1.76° (p=.006) mean difference seen in TL and SS, respectively. The overall profile of the sagittal curves remained largely similar, with only the lumbar apex shifting from L3 to L4 during the first and the second X-rays, respectively (p<.001). This occurred for the combined Lenke 1 and 2 subgroup as well (p<.001).Conclusion
Most radiographic sagittal spinal parameters in AIS patients are generally reproducible with some variations up to a maximum of 4°. This natural variation should be taken into account when interpreting these radiographic sagittal parameters so as to achieve the most accurate results in surgical planning. 相似文献Pelvic fixation via iliac screws is a crucial technique in stabilizing metastatic lumbosacral deformity. MIS iliac screw fixation avoids complications of an open approach and is a viable palliative option in treating patients with painful instability and advanced disease, unsuited for major reconstruction. In this paper we describe the use of MIS iliac screw fixation in treatment of painful metastatic LSJ deformity, highlighting our treatment rationale, selection criteria, technical experience and outcomes.
MethodsFive patients with lumbosacral metastatic deformity who underwent MIS lumbopelvic stabilization using iliac screws were prospectively studied. Patients had severe axial back pain in erect posture with significant resolution when supine. All patients had advanced disease with unfavorable tumor scores for major spinal reconstruction.
ResultsMean cohort age was 62 years. Median pre-op SIN and Tokuhashi scores were 13 and 9, respectively. All patients were instrumented successfully without conversion to open technique. Mean preoperative and postoperative Cobb angle was 11° and 5.4°, respectively. There were no neurological deficits or wound complications postop. Postoperative CT scans showed no iliac screw and sacroiliac joint bony violation. Mean time for commencement of adjuvant therapy was 2.8 weeks. Average follow-up was 13.2 months. No screw breakage, wound complication, symptomatic implant prominence and SI joint pain were noted at last follow-up.
ConclusionMIS iliac screw fixation is feasible, reproducible and can be employed without complications in metastatic spine. This opens a new avenue of surgical management for metastatic lumbosacral disease patients, who otherwise may be inoperable and provide better soft tissue control and earlier postoperative adjuvant treatment opportunity.
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