To evaluate the impact of thoracic spine degeneration in adult spinal deformity (ASD) patients on radiographic outcomes. Primary ASD patients undergoing thoracolumbar fusion with T9–L1 upper instrumented vertebra (UIV) and S1/ilium lower instrumented vertebra were included. Thoracic spine degeneration was assessed radiographically using Kellgren-Lawrence (KL) grading and segmented into T1–T5, T5–T9, and T9–L1 arcs per Lafage criteria. Arc degeneration was defined as ≥ 2 levels with KL grade 3 + in an arc and thoracic spine degeneration as ≥ 1 degenerated arc. Proximal zone degeneration was KL grade 3 + in the two levels above the UIV and distal zone degeneration was KL grade 3 + in unfused thoracic levels outside the proximal zone. Patients with no degenerated levels served as controls. Among 272 patients (mean age 65.1years, 74
Demonstration of tritium breeding blanket technique is one of the engineering goal of International Thermonuclear Experimental Reactor (ITER). Among the different blanket concepts, China decided to develop Heliumcooled Ceramic-Breeder Test Blanket Module (HCCB TBM) and tested in ITER specific TBM port. Currently CN HCCB TBM design is under preliminary design (PD) phase. In 2023, regarding some engineering and technical issues, ITER proposed to modify previous baseline scenario, with less than 1% of total neutron fluence in DT-1 phase, and reduced plasma pulse parameters. Regarding the testing goals of TBM programme, additional electrical heater was proposed to put inside TBM module, so as to achieve relatively high temperature for tritium release. In this paper, steady-state and transient thermo-hydraulic analysis was performed for HCCB TBM typical component, and the overall temperature distribution was achieved, which will be input for structural analysis and dynamic tritium transport analysis in the next step.
Adult spinal deformity patients undergoing total hip arthroplasty experience higher hip dislocation rates than those with normal spinal alignment. The traditional Lewinnek safe zone does not account for spinopelvic variation such as pelvic retroversion. To address this, three patient-specific normative zones for acetabular anteversion were defined. A multicenter retrospective analysis of 146 adult spinal deformity patients and 47 asymptomatic controls was performed using three-dimensional biplanar radiograph reconstructions to measure spinopelvic alignment and acetabular orientation. Normative Zone 1, for patients not undergoing spinal realignment, was delineated by the 95% confidence interval limits: minimum anteversion = 0.3182 × pelvic tilt +2.947 and maximum anteversion = 0.3317 × pelvic tilt +25.823. Normative Zone 2, for patients following spinal realignment, was based on pelvic incidence: minimum anteversion = 0.0682 × pelvic incidence +9.7749 and maximum anteversion = 0.0698 × pelvic incidence +21.5218. Normative Zone 3, intended for cases with uncertain spinal correction plans, was defined as the intersection of Zones 1 and 2, yielding a narrower target anteversion range. These zones enable patient-specific cup placement that accounts for existing or planned spinal alignment, with the potential to reduce dislocation risk. Clinical Significance: This study provides acetabular cup orientation tailored to each patient's spinopelvic alignment and surgical plan, potentially reducing dislocation rates in spinal malalignment patients.
STUDY DESIGN:Retrospective review of multicenter, prospective cervical deformity database. OBJECTIVE:To compare outcomes of extension of fusion to the cervical spine versus the upper thoracic (UT) spine. SUMMARY OF BACKGROUND DATA:Proximal junctional kyphosis (PJK) management after thoracolumbar fusion requires extension of fusion to the proximal spinal segments. Unlike extensions to the less mobile thoracic segments, crossing the cervicothoracic junction (CTJ) involves more mobile cervical segments and creates different biomechanical influences and clinical outcomes. No study has compared the outcomes of extending fusion to the cervical versus the UT spine. METHODS:Patients with thoracic PJK who underwent revision with extension of fusion to either the cervical or UT (T1 or T2) spine were identified in a multicenter, prospective cervical deformity database. Patients with cervical upper instrumented vertebra (UIV) were subdivided into lower cervical (LC; C4-7) and upper cervical (UC; and occiput-C3) groups. Baseline demographics, surgical variables, radiographic outcomes, 2-year health-related quality-of-life scores, complications, and revision rates were analyzed. RESULTS:Fifty-one patients (mean age: 60.4±12.9 y; 91% female) with at least 2 years of follow-up were included. Twelve had extension to the UT, 20 to the LC, and 19 to the UC spine. Demographic data, Charlson Comorbidity Index, follow-up duration, surgical parameters, radiographic measurements, recurrent PJK and reoperation rates, and 2-year patient-reported outcome scores were similar across groups. The instrumentation failure rate was higher in the LC (25%) than in the UT (0%) and UC (8%) groups (P=0.03). CONCLUSIONS:Stopping fusion at T1 or T2 did not result in greater complication or reoperation rates than extending to the cervical spine. The instrumentation-related complication rate was higher for extension to the LC than to the UC or UT spine. Crossing the CTJ should be individualized, but may not prevent additional proximal junctional-level problems in the management of thoracolumbar fusion PJK. LEVEL OF EVIDENCE:Level IV.
Lower limbs can play a major compensating role for sagittal malalignment; however, little is known about the different types of compensation. This study aimed to identify different patterns of lower limb compensation and to determine which parameters may affect the recruitment of knee flexion versus hip extension. This study included adult spinal deformity (ASD) patients with full-body X-rays in erect position from a multicentric prospective database. All parameters were measured at baseline: demographics, clinical scores and radiographic parameters: pelvic parameters, pelvic incidence-lumbar lordosis (PI-LL) mismatch, T1 pelvic angle (TPA), sacro-femoral angle (SFA), knee flexion angle (KA), ankle dorsi-flexion angle (AA), pelvic shift (PSh), hip and knee osteoarthritis (OA) grade. A K-means cluster analysis was conducted to identify patterns of lower limb compensation based on SFA and KA. The optimal number of clusters was determined using the silhouette score. The different parameters were then compared across clusters. 871 ASD patients were included, of whom 66.9
