Vertebra-disc ratio as a new predictor for curve progression in early thoracic AIS with bracing treatment.

OBJECTIVES: Previous studies have reported various predictors for curve progression in braced adolescent idiopathic scoliosis (AIS) patients. However, the reported predictors might be insufficient for patients with early AIS. The aim was to investigate whether the initial vertebra-disc ratio (VDR) could serve as an effective predictor for curve progression in early thoracic AIS (premenarchal and Risser 0) undergoing brace treatment. PATIENTS AND METHODS: This study reviewed a consecutive series of early thoracic AIS girls with thoracic curve. All patients had accepted brace treatment and had regular follow-up. According to the bracing outcomes, patients were divided into two groups: Group P (progressed, curve progressed over six degrees or indicated for surgery) and Group NP (non-progressed). RESULTS: Totally 203 girls were included. There were 73 and 130 patients in Groups P and NP, respectively. The patients in Group P had greater initial VDR (1.9 ± 0.5 vs. 0.8 ± 0.4, P < 0.01) than Group NP. During the follow-up, it showed continuous higher values in Group P than Group NP. The logistic regression analysis revealed that initial VDR had an effective value for predicting curve progression in the braced early AIS girls. The ideal cut-off point of initial VDR was 1.5 for the prediction of curve progression. CONCLUSION: The initial VDR could serve as an effective predictor for curve progression in braced early AIS girls. Evaluation of this new parameter should be carefully performed at the bracing initiation.

Does kyphotic configuration on upright lateral radiograph correlate with instability in patients with degenerative lumbar spondylolisthesis?

OBJECTIVE: To investigate the segmental instability of degenerative lumbar spondylolisthesis (DLS) with a kyphotic configuration at the involved segment, and to determine the most useful diagnostic modalities in the evaluation of instability. PATIENTS AND METHODS: This study reviewed a consecutive series of patients with L4/5 DLS between July 2010 and May 2016. The enrolled patients were divided into two groups based on preoperative neutral radiographs: the kyphotic group (Group K) and non-kyphotic group (Group NK). Translational and angular motion was determined by comparing upright lateral radiograph (U) with a supine sagittal MR image(S) (Combined, US) or flexion/extension radiographs (FE). RESULTS: There were 26 and 201 patients in Groups K and NK, respectively. In comparison to Group NK, Group K demonstrated significantly higher translational motion (12.4% vs. 7.0%, P < 0.001) on US analysis, but significantly lower translational motion (4.2% vs. 6.4%, P < 0.001) on FE analysis. Angular motion was detected to be significantly lower in US versus FE in Group NK (1.2° vs. 7.8°, P < 0.001), while of no difference in Group K (P > 0.05). In Group K, "instability" was recognized in 84.6% of patients using US versus 11.5% patients using FE (P < 0.001); While in Group NK, no significant difference was observed in the incidence of "instability" between FE and US (31.3% vs. 27.8%, P = 0.444). Overall, Group K had a significantly higher incidence of instability than Group NK (84.6% vs. 31.3%, P < 0.001). CONCLUSION: DLS with a kyphotic configuration is a distinct subgroup associated with segmental instability. The modality of US is shown to be superior to traditional FE in measuring translational motion and identifying instability for DLS patients with a kyphotic configuration.

Higher Improvement in Patient-Reported Outcomes Can Be Achieved After Transforaminal Lumbar Interbody Fusion for Clinical and Radiographic Degenerative Spondylolisthesis Classification Type D Degenerative Lumbar Spondylolisthesis.

BACKGROUND: Clinical and radiographic degenerative spondylolisthesis (CARDS) classification defines a distinct subset of patients with kyphotic angulation at the involved segment (type D). Research using CARDS classification to investigate motion characteristics at involved segments or patient-related outcomes (PROs) following surgical intervention is sparse. We investigated the relationship between CARDS type D spondylolisthesis and dynamic instability and PROs in type D versus non-type D spondylolisthesis. METHODS: We reviewed consecutive patients who received transforaminal lumbar interbody fusion for L4-5 spondylolisthesis between 2009 and 2015. Patients were assigned into type D and non-type D groups. Translational motion was determined by upright lumbar lateral radiography with supine sagittal magnetic resonance imaging or flexion and extension radiography. Demographics, radiographic parameters, and PROs were evaluated. RESULTS: Type D and non-type D groups comprised 34 and 163 patients, respectively. Compared with non-type D, type D group was characterized by lordotic angulation loss and higher degree of olisthesis on upright radiographs and demonstrated higher translational motion on upright lumbar lateral radiography with supine sagittal magnetic resonance imaging analysis. After surgery, mean reduction rate was significantly higher in type D group; type D had less slippage, but differences in slip angle and disc height were not significant. Preoperative Oswestry Disability Index and visual analog scale for back pain scores were higher in type D group. Type D spondylolisthesis and dynamic instability were associated with achieving minimal clinically important differences in PROs. CONCLUSIONS: CARDS type D spondylolisthesis is a distinct subset associated with dynamic instability and worse PROs. Higher improvement in PROs can be achieved in CARDS type D spondylolisthesis after surgery.

Incidence, Risk Factors, and Evolution of Proximal Junctional Kyphosis After Posterior Hemivertebra Resection and Short Fusion in Young Children With Congenital Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: To investigate the incidence, risk factors, and evolution of proximal junctional kyphosis (PJK) in young children who underwent posterior hemivertebra resection and short fusion. SUMMARY OF BACKGROUND DATA: PJK is an undesired, but common complication following posterior spinal fusion. However, there is a paucity of data on PJK in young children after posterior hemivertebra resection and short fusion. METHODS: This study included 189 children who had undergone posterior hemivertebra resection and short fusion (≤4 vertebra) from January 2008 and May 2015 at a single institution. Medical records were reviewed and radiographic assessments were made preoperatively and throughout the follow-up period. Risk factors for PJK were evaluated by correlation analysis and logistic regression analysis. RESULTS: The mean age at surgery was 4.5 years (range, 3-10 yr) and the average follow-up was 48.4 months (range, 24-87 mo). Twenty-two (11.6%) patients experienced PJK. PJK was identified within 6 months after surgery in 21 cases (95%), and the most common type was ligamentous failure. In comparison with the non-PJK group, the PJK group had greater preoperative segmental kyphosis (26.9° vs. 16.7°, P < 0.01), longer fusion levels (3.4 vs. 2.5, P < 0.01), and larger postoperative sagittal vertical axis (SVA; 18.9 vs. 8.6 mm, P < 0.01). Preoperative segmental kyphosis >30°(odds ratio, 4.426), and postoperative SVA of more than 20 mm (odds ratio, 3.580) were identified as independent risk factors for PJK. In PJK group, the average proximal junctional angle increased from 4.9° to 18.5° at 6 months postoperatively, but significantly decreased to 14.8° at final follow-up. Eleven patient received brace treatment, and no patients required revision surgery. CONCLUSION: Despite the incidence of PJK in 11.6% of young children undergoing posterior hemivertebra resection and short fusion, no significant deterioration of proximal junctional angle were found till the last follow-up. Its risk factors include preoperative segmental kyphosis, a larger postoperative SVA and ligamentous failure. Early detection and active management may be helpful for minimizing the progression of PJK. LEVEL OF EVIDENCE: 3.

Coronal Decompensation After Posterior-only Thoracolumbar Hemivertebra Resection and Short Fusion in Young Children With Congenital Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence and risk factors of coronal decompensation after posterior-only thoracolumbar hemivertebra (HV) resection and short fusion in patients younger than 5-years old. SUMMARY OF BACKGROUND DATA: Postoperative coronal decompensation may occur in operated patients during the follow up. However, there is a paucity of valid data regarding this complication in very young patients with thoracolumbar HV. METHODS: This study reviewed a consecutive series of patients (younger than 5 years) who had undergone posterior-only hemivertebrectomy and short fusion from January 2006 to December 2014. They had a minimum follow-up of 24 months. According to the coronal compensation behavior, they were divided into two groups: Group P (progressed, curve decompensated beyond twenty degrees) and Group NP (nonprogressed, curve well compensated). RESULTS: There were 179 patients included in this study. Mean age at surgery was 38 ±â€Š11 months. Mean follow-up was 41 ±â€Š11 months. Postoperative coronal decompensation was identified in 18 patients (rate, 10.1%) who constituted Group P. The remaining 161 patients had a well-compensated pattern. In contrast to Group NP, the patients in Group P had greater preoperative lowest instrumented vertebra (LIV) translation (18.5 mm ±â€Š6.4 mm vs. 10.5 mm ±â€Š4.9 mm, P < 0.01), and higher postoperative LIV disc angle (7.0°â€Š±â€Š3.1° vs. 3.1°â€Š±â€Š3.3°, P < 0.01) after surgery. During the follow up, LIV translation and LIV disc experienced continuous aggravation until initiation of bracing. Preoperative LIV translation (≥15.1 mm) and postoperative LIV disc angle (≥5.5°) were identified as two independent risk factors of coronal decompensation after surgery. CONCLUSION: After thoracolumbar hemivertebrectomy in children younger than 5 years, the overall rate of coronal decompensation is approximately 10.1%. As two independent risk factors of postoperative coronal decompensation, preoperative LIV translation (≥15.1 mm) and postoperative LIV disc angle (≥5.5°) should on all accounts be the major causes for concern. LEVEL OF EVIDENCE: 4.

Adding Satellite Rods to Standard Two-rod Construct With the Use of Duet Screws: An Effective Technique to Improve Surgical Outcomes and Preventing Proximal Junctional Kyphosis in Posterior-Only Correction of Scheuermann Kyphosis.

STUDY DESIGN: A retrospective matched-cohort comparative study. OBJECTIVE: The aim of this study was to compare the surgical results after the use of duet screw based satellite rods and bilateral satellite rods (S-RC) versus a standard two-rod construct (2-RC) across osteotomy sites in a matched cohort with Scheuermann kyphosis (SK). SUMMARY OF BACKGROUND DATA: Multiple Ponte osteotomies are frequently employed to correct SK via a posterior-only approach, with a 2-RC across the osteotomy sites. Whereas, correction rate and junction problems remain as the major concerns. METHODS: This study reviewed a consecutive series of patients with SK who had undergone posterior-only correction with multilevel Ponte osteotomy between 2009 and 2014 and had been followed over 24 months. Twenty-two patients receiving placement with an S-RC with the use of duet screws were identified and closely matched with 22 patients with a 2-RC in terms of age, apex, and magnitude of kyphosis. Comparisons were made with regards to deformity magnitude, correction results, complications, and clinical outcomes between the two groups. RESULTS: No significant difference was found between groups in preoperative patient's factors (age, gender, apex, magnitude of kyphosis, and SRS-22 scores) and surgical factors (blood loss, operation time, osteotomy levels, and fused levels). Compared with the 2-RC group, the S-RC group had higher correction rate (55.4% ±â€Š7.5% vs. 46.2% ±â€Š5.1%, P < 0.001), less correction loss (1.0 ±â€Š0.8° vs. 2.4 ±â€Š1.4°, P < 0.001) during the follow-up, and higher improvement of back pain as well (P < 0.05). None were detected with pseudarthrosis or implant failure in either group, but proximal junctional kyphosis was less frequently seen in S-RC group (1 of 22) than 2-RC group (7 of 22) (P < 0.05). CONCLUSION: As a safe method, use of S-RC is effective in providing increased kyphotic correction across multiple Ponte osteotomy levels, and improving patient-reported outcomes of management satisfaction and back pain. The biomechanical benefits of stress dispersion, coupled with increased stability and weight bearing ability, make it a powerful technique preventing correction loss and proximal junctional kyphosis. LEVEL OF EVIDENCE: 3.

Proximal Junctional Kyphosis After Posterior Spinal Instrumentation and Fusion in Young Children With Congenital Scoliosis: A Preliminary Report on its Incidence and Risk Factors.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence and risk factors of proximal junctional kyphosis (PJK) in young children who underwent posterior instrumented spinal fusion. SUMMARY OF BACKGROUND DATA: PJK is a well-recognized postoperative complication in adults and adolescents. However, there is a paucity of valid data with regard to PJK in young children with congenital scoliosis (CS) who were treated with posterior correction surgery. METHODS: This study reviewed the charts and radiographs of a consecutive series of young children with CS who underwent posterior instrumentation and fusion (≥4 levels) from January 2008 to May 2013. The patients were followed up for more than 24 months. Radiographic measurements were made preoperatively and throughout the follow-up period. From sagittal images, the following values were obtained: proximal junctional angle, sagittal vertical axis, pelvic incidence, thoracic kyphosis, lumbar lordosis, and segmental kyphosis. RESULTS: Totally 113 children were recruited in this study. The average age at surgery was 6.6 years, and the average follow-up period was 48.8 months. PJK occurred in 21 of the 113 patients and were mostly classified as ligamentous failure. In comparison with the non-PJK group, the PJK group showed greater preoperative Thoracic kyphosis (TK) (45.9° vs. 37.3°, P = 0.027), longer fusion levels (6.6 vs. 5.4, P < 0.01), and greater segmental kyphosis (SK) change (30.1° vs. 11.2°, P = 0.002). Both a change in SK greater than 30° and a preoperative TK greater than 40° were independent risk factors associated with PJK. In the PJK group, the average PJA increased by 12.4° at 3 months postoperatively and followed by slight improvement till the final follow-up. CONCLUSION: This study demonstrates a high rate of PJK in young children after correction surgery for CS. PJK mainly occurs within 3 months postoperatively and its risk factors include preoperative hyperkyphosis, over-correction of kyphosis, and ligamentous failure. LEVEL OF EVIDENCE: 4.

Does addition of crosslink to pedicle-screw-based instrumentation impact the development of the spinal canal in children younger than 5 years of age?

PURPOSE: Use of pedicle screws has been popularized in the treatment of pediatric spinal deformity. Despite many studies regarding the effect of pedicle screws on the immature spine, there is no study concerning the impact of addition of crosslink to pedicle-screw-based instrumentation on the development of the spinal canal in young children. This study aims to determine the influence of the screw-rod-crosslink complex on the development of the spinal canal. METHODS: This study reviewed 34 patients with congenital scoliosis (14 boys and 20 girls) who were treated with posterior-only hemivertebrectomy and pedicle-screw-based short-segment instrumentation before the age of 5 years. The mean age at surgery in this cohort was 37 ± 11 months (range 21-57 months). They were followed up for at least 24 months. Of these patients, 10 underwent only pedicle screw instrumentation without crosslink, and 24 with additional crosslink placement. The vertebrae were divided into three regions as follows: (1) S-CL (screw-crosslink) region, in which the vertebrae were inserted with bilateral pedicle screws and two rods connected with the crosslink; (2) S (screw) region, in which the vertebrae were inserted with bilateral pedicle screws but without crosslink; (3) NS (no screws) region, which comprised vertebrae cephalad or caudal to the instrumented region. The area, anteroposterior and transverse diameters of the spinal canal were measured at all vertebrae on the postoperative and last follow-up computed tomography axial images. The instrumentation-related parameters were also measured, including the distance between the bilateral screws and the screw base angles. The changes in the above measurements were compared between each region to evaluate the instrumentation's effect on the spinal canal growth. RESULTS: The mean follow-up was 37 ± 13 months (range 24-68 months) and the mean age at the last follow-up was 74 ± 20 months (range 46-119 months). In each region, the spinal canal dimensions significantly increased during the follow-up period. There was no significant difference in the spinal canal growth rate between the S and NS regions or between the S-CL and NS regions. Besides, a comparison of the S-CL and S regions regarding the changes in the measurements of the instrumentation construct revealed no significant differences. CONCLUSION: Pedicle-screw-based instrumentation does not cause retardation of the development of the spinal canal in young children. Moreover, use of the crosslink added to the screw-rod instrumentation also demonstrates no negative effect on the growth of the spinal canal. Thus, the addition of the crosslink to short screw-based instrumentation is recommended as an alternative to increase fixation stability in growing patients, even in very young pediatric population.

Square structures and photophysical properties of Zn(2)Ln(2) complexes (Ln = Nd, Eu, Sm, Er, Yb).

Heterotetranuclear Zn(2)Ln(2) (Ln = Nd , Eu , Sm , Er , Yb ) complexes {Zn(2)(Mq)(2)(tpyO)(2)}{(Ln(hfac)(3))(2)} (HMq = 2-methyl-8-hydroxylquinoline, tpyOH = [2,2':6'2'']terpyridin-4'-ol, hfac = hexafluoroacetylacetonate) display novel square structures ligated by bifunctional ligands tpyO (mono- and tridentate) and Mq (chelating and bridging mu-phenoxo). These compounds exhibit sensitized lanthanide emission upon photo-excitation of ZnMq/tpy antenna chromophores. By virtue of the dual luminescence with complementary colors, the ZnMq/tpyO-based cyan emission and Sm(III)-centered orange luminescence are combined to generate a white-light emission in Zn(2)Sm(2) (4) complex.

Sensitization of lanthanide luminescence by two different Pt-->Ln energy transfer pathways in PtLn3 heterotetranuclear complexes with 5-ethynyl-2,2'-bipyridine.

Reactions of 5-[2-(trimethylsilyl)-1-ethynyl]-2,2'-bipyridine (Me3SiC-Cbpy) with Pt(bpy)C12 (bpy = 2,2'-bipyridine) and Pt(bpyC[triple bond]C-C[triple bond]Cbpy)Cl2 (bpyC[triple bond]C-C[triple bond]Cbpy=bis(2,2'-bipyridin-5-yl)butadiyne) induced isolation of Pt(bpy)(C[triple bond]Cbpy)2 (1) and Pt(bpyC[triple bond]C-C[triple bond]Cbpy)(C[triple bond]Cbpy)2 (5), respectively. Incorporating Ln(hfac)3(H2O)2 (hfac = hexafluoroacetylacetone) with 1 or 5 gave the corresponding PtLn2 (Ln = Nd (2), Eu (3), Yb (4)) or PtLn3 arrays (Ln=Nd (6), Eu (7), Gd (8), Yb (9)). With excitation at 360 < or = lamda(ex)0 < or =480 nm, which is the MLCT absorption region of the Pt(2,2'-bipyridyl)(acetylide)2 chromophore, sensitized lanthanide luminescence is successfully attained by efficient Pt-->Ln energy transfer from the Pt(II) antenna chromophores. In contrast with quite efficient Pt-->Ln energy transfer in the Pt-C[triple bond]Cbpy-Ln(Pt...Ln = 8.6 A) array, energy transfer transmitted across the Pt-bpyC[triple bond]C-C[triple bond]Cbpy-Ln(Pt...Ln = 13.3 A) array is less efficient owing to the much longer Pt...Ln separation in the latter.

[Safety destruction of tetramethylene disulfotetramine and its medical waste].

OBJECTIVE: To develop suitable methods for safety destruction of tetramethylene disulfotetramine (TETS) and the medical wastes polluted by TETS. METHODS: The chemical stability of TETS was evaluated under the conditions of acid, alkali and high temperature. TETS was treated with sodium hydroxide, hydrochloric acid, sulfuric acid and nitric acid under various treatment conditions, i.e. concentration, temperature and time, followed by determining remaining TETS using gas chromatograms to estimating the degradation efficiency of TETS. TETS was put into ampoule and heated under the different conditions of temperature and time. After heat treatment, TETS residue was determined. For evaluating the absorption factor of active carbon to TETS in water and blood, active carbon was added into the water and blood with content of TETS, incubated at room temperature for 24 hours, and then determined the remaining TETS in water and blood. RESULTS: The complete degradation of TETS was achieved by one of the following treatments: heating with 6.0 mol/L hydrochloric acid at 100 degrees C for half an hour, heating with 3.0 mol/L hydrochloric acid or 6.0 mol/L sodium hydroxide at 100 degrees C for 3 hours, mixing with concentrated sulfuric acid or nitric acid at room temperature for 24 hours, and dry heating at 300 degrees C for 4.5 hours. Active carbon showed a marked effectiveness in absorbing the TETS in blood and water, with the mean absorption efficiency of over 90%. CONCLUSIONS: The results of this study suggest that TETS powder should be degraded by acid or alkali, and that the solid medical wastes polluted by TETS should be destroyed at high temperature. For the blood and water having contents of TETS, the active carbon should be used as to absorbing the TETS and then be destroyed at high temperature.