[Influence of paraspinal muscle degeneration and postoperative Roussouly classification restoration on mechanical complications in female patients with degenerative scoliosis after surgery].

Objective: To investigate the impact of lumbar paraspinal muscle degeneration and postoperative failure to restore ideal Roussouly classification on the occurrence of mechanical complications (MC) following long-segment spinal correction surgery in female patients with degenerative scoliosis (DS). Methods: The clinical data of 72 female DS patients who underwent long-segment spinal correction surgery in Gulou Hospital from June 2017 to November 2021 were retrospectively analyzed. According to whether restoring the ideal Roussouly classification after surgery, the patients were divided into R group(recovery group) (n=51) and N group(non-recovery group) (n=21). According to whether mechanical complications occurred after operation within two years, the patients were divided into MC (mechanical complications)group (n=24) and NMC(non-mechanical complications) group (n=48). The RM group (n=14) experienced mechanical complications in the R group, while the RN group (n=37) did not. The NM group (n=10) experienced mechanical complications in the N group, while the NN group (n=11) did not.Radiographic assessment included Sagittal parameters of spine and pelvis, standardized cross-sectional area (SCSA) and fat infiltration rate (FI%) of paraspinal muscle at each lumbar disc level. Results: The age of DS patients in this study was (61.4±6.2) years.The incidence of MC was 33.33%(n=24)in all patients. The incidence of MC was 27.45%(n=14)in group R and 47.62%(n=10) in group N. The correction amount of pelvic tilt angle (PT) (-11.62°±10.06° vs -7.04°±8.45°, P=0.046) and T1 pelvic angle(TPA)(-12.88°±11.23° vs -7.31°±9.55°, P=0.031)during surgery were significantly higher in MC group compared to the NMC group. In group R, the FI% of paraspinal muscles in each lumbar segment of patients with postoperative MC was higher than that in patients without MC (P<0.05). In the R and N groups, there was no significant difference inthe SCSA of the lumbar paravertebral muscles between patients with postoperative MC and those without MC at each level (all P>0.05). Multivariate logistic regression analysis showed that the average FI% of lumbar PSM was correlated with the occurrence of MC after spinal fusion in DS patients.The average FI% of lumbar PSM≥22.63% was a risk factors for MC after spinal fusion (P=0.010,OR=1.088, 95%CI:1.020-1.160). Conclusions: Female DS patients with higher degree of preoperative paraspinal muscle degeneration have a higher incidence of postoperative mechanical complications. For these patients,.there is still a higher risk of mechanical complications after surgery even if the ideal Roussouly classification is restored after surgery.

[Clinical study of the Cobb+1 to Cobb fusion strategy for Lenke 5C adolescent idiopathic scoliosis patients with the lower lumbar apex].

Objective: To investigate the indications and surgical outcome of Cobb+1 to Cobb fusion strategy in Lenke 5C adolescent idiopathic scoliosis (AIS) patients with the lower lumbar apex. Methods: The clinical data of Lenke 5C AIS patients treated in Nanjing Drum Tower Hospital from August 2015 to December 2018 were retrospectively analyzed. The patients were followed-up for at least 2 years after surgery and treated with selective Cobb+1 to Cobb fusion strategy. The patients were divided into the normal lumbar apex group (apex location of the main curve was between T12 and L1) and the lower lumbar apex group (apex location of the main curve was below the disc of L1/L2). The occurrence of proximal decompensation in the two groups was compared. In addition, according to whether the patients had proximal decompensation at the last follow-up, the patients in the lower lumbar apex group were further divided into proximal decompensation group and non-decompensation group. The radiographic parameters and Scoliosis Research Society-22 (SRS-22) scores of the two groups were compared. Results: A total of 52 patients (19 cases in the normal lumbar apex group and 33 cases in the lower lumbar apex group), aged (15.3±1.6) years, were followed up for 2-5 (3.2±1.2) years. Six patients (6/19) in the normal lumbar apex group and 5 cases (15.2%) in the lower lumbar apex group showed proximal decompensation during follow-up, and the incidence was significantly higher in the normal lumbar apex group (P=0.034). Within the lower lumbar apex group, the patients with proximal decompensation (n=5) showed similar Risser grade, baseline thoracic Cobb angle, and main Cobb angle as those without proximal decompensation(n=28), and the differences were all not statistically significant (all P>0.05). However, the baseline thoracic/lumbar apical vertebra translation (AVT) ratio was significantly larger in patients with proximal decompensation (0.6±0.2 vs 0.4±0.2, P=0.042), but the postoperative upper instrumented vertebra (UIV) tilt angle was similar (4.5°±2.3° vs 6.2°±3.4°, P=0.312). Conclusion: Cobb+1 to Cobb fusion strategy, selecting UIV at 1 level above upper end vertebra (UEV), could be performed in Lenke 5C patients with the lower lumbar apex location. In addition, UIV could be selected at UEV+1 in patients with small baseline thoracic curve.

[Effect of different observations on evaluation of cosmetic shoulder balance in adolescent idiopathic scoliosis patients with thoracic curve].

Objective: To investigate the correlations between cosmetic and radiographic parameters of shoulder balance, as well as the variations in cosmetic shoulder balance observed from different perspectives, among patients with adolescent idiopathic scoliosis (AIS) characterized by thoracic curves. Methods: A total of 43 patients with thoracic curves treated from July to October in 2022 in Nanjing Drum Tower Hospital were recruited in this study. There were 9 males and 34 females with a mean age of (14.3±1.5) years. All participants underwent comprehensive radiographic assessments and were photographed both from posterior and anterior views, focusing on the shoulder region as well as a higher level (maintaining a consistent vertical distance of 180 cm from the ground). Six cosmetic parameters were measured on the photographs: shoulder angle(α1), axilla angle(α2), shoulder area index 1(SAI1), shoulder area index 2 (SAI2), inner shoulder height (SHi) and outer shoulder height (SHo). Eight radiographic parameters were measured on the radiographs: radiographic shoulder height difference (RSHD), first rib angle (FRA), clavicle-rib cage intersection (CRCI), coracoid process height (CPH), T1 tilt, clavicle angle(CA), clavicle chest cage angle difference (CCAD) and Cobb angle. Differences among bilateral cosmetic indicators from different perspectives were analyzed and compared, and their correlation with bilateral radiographic indicators was studied. Results: There was no significant differences between anterior cosmetic parameters and posterior cosmetic parameters at the same level of observation(all P>0.05). However, when observing SHi, SHo, α1, and α2 at the shoulder level, it became evident that they exhibited significantly higher values compared to the corresponding higher level on the same side of the patients' bodies. This contrast was observed in both the dorsal [SHo: (0.11±1.20) cm vs (-0.44±1.39) cm, P=0.005; SHi: (0.64±0.86) cm vs (0.32±0.56) cm, P=0.003; α1:-0.47°±2.27° vs -0.77°±2.49°, P=0.014; α2:-3.06°±3.23° vs -2.21°±3.03°, P=0.034] and ventral [SHo: (0.12±1.29) cm vs (-0.48±1.35) cm, P=0.007; SHi: (0.61±0.88) cm vs (0.30±0.59) cm, P=0.006; α1:-0.46°±2.18° vs -0.69°±2.35°, P=0.018; α2:-3.26°±3.12° vs -2.05°±2.97°, P=0.029] aspects of the patients. SHi and SHo were more sensitive to this difference of height. The correlation coefficients between radiographic parameters and cosmetic aspects at the shoulder level varied from 0.374 to 0.767. Similarly, the correlation coefficients between radiographic parameters and cosmetic factors at the higher level ranged from 0.273 to 0.579 (all P<0.05). Conclusions: The cosmetic parameters had significant difference between different perspective of observation, the cosmetic parameters are needed to be observed at the shoulder level in the evaluation of patients' shoulder balance.

[Comparison of intraoperative neurophysiological monitoring between patients with arthrogryposis multiplex congenita and adolescent idiopathic scoliosis].

Objective: To compare the intraoperative neurophysiological monitoring (IONM) results between patients with arthrogryposis multiplex congenita (AMC) and adolescent idiopathic scoliosis (AIS) and to analyze the influence of congenital spinal deformity on IONM in AMC patients, thus to evaluate the efficiency of IONM in AMC patients. Methods: A cross-sectional study. The clinical data of 19 AMC patients underwent correction surgery from July 2013 to January 2022 in Nanjing Drum Tower Hospital were retrospectively reviewed. There were 13 males and 6 females with a mean age of (15.2±5.6) years, and the average Cobb angle of main curve was 60.8°±27.7°. And 57 female AIS patients of similar age and curve type with the AMC patients during the same period were selected as the control group, with an average age of (14.6±4.4) years and a mean Cobb angle of 55.2°±14.2°. The latency and amplitude of samatosensory evoked potentials (SSEPs) and transcranial electric motor evoked potentials (TCeMEPs) were compared between the two groups. The difference in IONM data between AMC patients with and without congenital spinal deformity was also evaluated. Results: The success rates of SSEPs and TCeMEPs were 100% and 14/19 for AMC patients, 100% and 100% for AIS patients. The SSEPs-P40 latency, SSEPs-N50 latency, SSEPs-amplitude, TCeMEPs-latency, TCeMEPs-amplitude showed no significant difference between AMC patients and AIS patients (P>0.05 for all). The side-difference of TCeMEPs-amplitude showed an increasing trend in AMC patients when compared with that in AIS patients, but there was no statistical difference between the two groups [(147.0±185.6) µV vs (68.1±311.4) µV, P=0.198]. The SSEPs-amplitude value was (1.4±1.1) µV on concave side in AMC patients with congenital spinal deformity, and it was (2.6±1.2) µV on concave side in AMC patients without congenital spinal deformity (P=0.041). The SSEPs-amplitude value was (1.4±0.8) µV on convex side in AMC patients with congenital spinal deformity, and it was (2.6±1.3) µV on convex side in AMC patients without congenital spinal deformity (P=0.028). Conclusions: The values of SSEPs-P40 latency, SSEPs-N50 latency, SSEPs-amplitude, TCeMEPs-latency and TCeMEPs-amplitude are similar in AMC and AIS patients. The SSEPs-amplitude of AMC patients with congenital spinal deformity is lower than that of AMC patients without congenital spinal deformity.

Monolayer MSi2P4 (M = V, Nb, and Ta) as Highly Efficient Sulfur Host Materials for Lithium-Sulfur Batteries.

Despite the high capacity and low cost of lithium-sulfur (Li-S) batteries, their commercialization is greatly blocked by multiple bottlenecks including the shuttle effect of lithium polysulfides (LiPSs), poor conductivity of sulfur, and sluggish reaction kinetics. Herein, we propose novel two-dimensional MSi2P4 (M = V, Nb, and Ta) monolayers as promising sulfur hosts to improve the Li-S battery performance. Our calculations show that MSi2P4 monolayers offer moderate binding strengths to the polysulfides, which are expected to effectively inhibit the LiPS shuttling and dissolution. Moreover, the conductive properties of the MSi2P4 systems are well maintained after LiPS adsorption, eliminating the insulating nature of sulfur species. Remarkably, MSi2P4 monolayers exhibit superior electrocatalytic activity for the sulfur reduction reaction and the Li2S decomposition reaction, which considerably lowers the energy barriers of LiPS conversions during discharge and charge, thus ensuring the fast redox kinetics and high sulfur utilization of Li-S batteries. This study pioneers the application of MSi2P4 monolayers as highly efficient sulfur host materials for Li-S batteries and affords insights for further development of advanced Li-S batteries.

[Impact of C2-femoral heads center and sacroiliac fixation on the occurrence of post-operative proximal junctional kyphosis in adults with spinal deformity].

Objective: To analyze the relationship between post-operative proximal junctional kyphosis (PJK) and C2-femoral heads center (C2-FH), pelvic fixation in adult spinal deformity (ASD) patients, so as to provide a reference for the preoperative decision-making and the postoperative intervention timely. Methods: It was a retrospective study that analyzed 34 cases of ASD patients who underwent posterior pedicle screw fixation in Nanjing Drum Tower Hospital between January 2017 and May 2017. ASD patients were divided into two groups according to fixation options: the sacroiliac fixation group and the non-sacroiliac fixation group. The spine-pelvis parameters were evaluated on full-length X ray films of spine at preoperatively, 2 weeks postoperatively and the last follow-up, and the incidence of PJK was recorded. Results: A total of 34 ASD patients (3 males and 31 females) were included in this study, with an average age of (58±6) years. The mean follow-up period was (2.9±1.0) years (2.0-4.0 years). The age, follow-up time and various spine-pelvis parameters showed no significant differences between the two groups (all P>0.05). The immediate postoperative C2-FH in the sacroiliac fixation group was significantly lower than that in the non-sacroiliac fixation group [(-69.46±30.85) mm vs (-31.62±15.31) mm, P<0.001]. The incidence of PJK was as high as 50.0% (8/16) in patients with sacroiliac fixation, but it was only 22% (4/18) in patients without sacroiliac fixation (P=0.016). At the last follow-up, the C2-FH of both groups were both higher than -20 mm (both were approximately -15 mm, P=0.976), indicating that the C2-FH was compensated in both groups. Due to the loss of the distal compensation ability, the incidence of PJK in the sacroiliac fixation group was higher than that in the non-sacroiliac fixation group. Due to the fixation of pelvis and most of lumbar spine, no significant differences were found in lumbar lordosis (LL), pelvic tilt (PT) and sacral slope (SS) at the last follow-up in both groups when compared with those after the operation (all P>0.05); while the thoracic kyphosis (TK) and cervical lordosis (CL) increased significantly (both P<0.05) to compensate C2-FH at the last follow-up. Conclusion: It's demonstrated that C2-FH< -2 cm and pelvic fixation are high risk factors of PJK in ASD patients. It is suggested that both global sagittal balance and pelvic fixation should be considered in decision-making and corrective surgery, rather than only focusing on spine-pelvic parameters.

[Neurological complications after three-column osteotomy in spinal deformity patients with different magnetic resonance imaging -based classification of spinal cord shape].

Objective: To compare the incidences of neurological complications after three-column osteotomy based on the magnetic resonance imaging(MRI)-based classification of spinal cord shape and cerebrospinal fluid in patients with severe thoracic kyphoscoliosis. Methods: A total of 112 patients (52 males, 60 females, age (M(Q1,Q3)) 13.5 years (9.0-38.5 years)) with thoracic kyphoscoliosis who underwent three-column osteotomy in Nanjing Drum Tower Hospital from August 2015 to August 2018 were retrospectively analyzed. The radiographic parameters including spinal cord morphology at apex, Cobb angle of main curve, distance between C7 plumb line and center sacral vertical line (C7PL-CSVL), global kyphosis (GK) and sagittal vertical axis (SVA) were measured, retrospectively. The Frankel scoring system was used for the evaluation of neurological status at pre-operation, post-operation and the last follow-up. Results: The spinal cord morphologies at apex were classified into type Ⅰ in 8 (7.1%) patients, type Ⅱ in 58 (51.8%), and type Ⅲ in 46 (41.1%), respectively. The patients were followed-up for (28.5±3.4) months. Compared with pre-operation, the Cobb angle of main curve, C7PL-CSVL, GK and SVA showed significantly improvement at post-operation (all P<0.05) and with no significant correction loss at the last follow-up (all P>0.05). New neurological complications were detected in 3 patients with type Ⅱ spinal cord shape, of whom the neurological scores were Frankel D at post-operation. For patients with type Ⅲ spinal cord shape, new neurological complications were detected in 6 patients including 1 Frankel C and 5 Frankel D. In addition, deterioration of neurological status from Frankel D to Frankel C was found in 3 patients with type Ⅲ spinal cord shape. The incidence of new or deteriorating neurological complications in patients with type Ⅲ spinal cord shape was higher than that in type Ⅱ patients (19.6% vs 5.2%, P=0.037). Conclusions: The MRI-based classification is associated with post-operative neurological complications in patients with severe kyphoscoliosis undergoing three-column osteotomy. Patients with type Ⅲ spinal cord shape are at higher risk of post-operative neurological complications.

[Different concentrations of specialized pro-resolving mediators in eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps].

Objective: To investigate the difference of concentrations of specialized pro-resolving mediators (SPMs) derived from fatty acids in eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) and non-eosinophilic chronic rhinosinusitis with nasal polyps (nECRSwNP). Methods: A total of 36 patients with bilateral chronic rhinosinusitis with nasal polyps (CRSwNP) who underwent endoscopic nasal surgeries in Peking Union Medical College Hospital from May 2019 to September 2020 were enrolled, including 27 males and 9 females, with the age from 13 to 67 years. There were 23 cases of ECRSwNP and 13 cases of nECRSwNP. At the same time, 12 control subjects were enrolled. The concentrations of multiple SPMs, including lipoxins (LXA4 and LXB4), resolvins (RvD1, RvD2, RvD3, RvD5 and RvE1), protectins (PDX) and maresins (Mar-1) in nasal polyps with different histological subtypes and normal nasal mucosa were analyzed using liquid chromatography-tandem mass spectrometry. The concentrations of SPMs between groups were compared using Mann-Whitney U test. Spearman's rank correlation coefficient was used to measure the correlation between the concentrations of SPMs in nasal polyps and tissue eosinophil counts. Results: The concentrations of RvD2, RvD3, RvD5, LXA4, LXB4, Mar-1 and PDX in ECRSwNP group were significantly higher than that in controls (Z value was -2.276, -2.313, -3.371, -2.094, -2.051, -3.104 and -2.294, respectively, all P<0.05). The concentrations of RvD2, RvD5, Mar-1 and PDX in ECRSwNP group were significantly higher than those in nECRSwNP group (Z value was -2.175, -2.289, -2.243 and -2.124, respectively, all P<0.05). There was no significant difference in all these SPMs between nECRSwNP and controls (all P>0.05). The concentrations of RvD2, RvD3, RvD5, LXB4, Mar-1 and PDX in nasal polyps correlated positively with tissue eosinophil counts (r value was 0.443, 0.436, 0.371, 0.502, 0.340 and 0.386, respectively, all P<0.05). Conclusions: A varienty of SPMs are elevated in ECRSwNP. Dysregulation of fatty acid metabolism might play an important role in the chronic inflammation of ECRSwNP.

[Clinical study of selection of the upper instrumented vertebra at one level caudal to upper end vertebra in patients with Lenke 5C adolescent idiopathic scoliosis].

Objective: To investigate whether the upper instrumented vertebra (UIV) can be selected at one level caudal to upper end vertebra (UEV) in Lenke type 5C adolescent idiopathic scoliosis (AIS) patients. Methods: Total of 28 Lenke 5C AIS patients who underwent selective posterior fusion in Drum Tower Hospital of Nanjing University Medical School from September 2013 to September 2015 were included. There were 4 males and 24 females, with an age of (15.0±2.0) years, the Risser sign was graded 2-5. The following imaging parameters were measured on standing full spine X-ray before, immediately after the surgery and at the last follow-up: thoracolumbar/lumbar (TL/L) Cobb angle, coronal balance, UIV translation, lower instrumented vertebra (LIV) translation, UIV tilt, LIV tilt, and thoracic apical vertebral translation (T-AVT), lumbar apical vertebral translation (L-AVT). The patients were divided into two groups: decompensation group (n=6) and non-decompensation group (n=22). Radiographic parameters and Scoliosis Research Society (SRS)-22 scores were compared between the two groups. Results: Six cases (21.4%) had proximal decompensation at the last follow-up. There were no significant differences in Risser grade(3.8±1.0 vs 3.6±1.6), baseline thoracic Cobb angle(25.8°±2.2° vs 26.3°±6.4°) and TL/L Cobb angle(43.7°±3.4° vs 45.2°±6.5°) between the two groups (all P>0.05). However, the baseline lumbar/thoracic apical vertebra translation (L-T AVT ratio) was significantly higher in patients with proximal decompensation (6.3±1.3 vs 4.0±2.0, P=0.048). Conclusion: Selecting UIV at one level caudal to UEV, would not increase the incidence of proximal decompensation in Lenke 5C AIS patients with Risser higher than grade 2, the smaller baseline L-T AVT ratio, and with thoracic compensatory curve over 15°, and can obtain satisfactory clinical results.

[Clinical application of minimally invasive lumbar interbody fusion].

With the popularization of minimally invasive concept in the treatment of lumbar degenerative disease,minimally invasive lumbar interbody fusion has gradually developed into the mainstream technique of lumbar fixation and fusion.At present,there are many types of minimally invasive lumbar interbody fusion. In this paper, four kinds of minimally invasive lumbar interbody fusion (anterior lumbar interbody fusion,minimally invasive transforaminal lumbar interbody fusion,extreme lateral interbody fusion,oblique lumbar interbody fusion),which are widely used in clinical practice,are systematically described from the aspects of indication selection,technical characteristics, clinical efficacy and prevention of complications.In order to obtain the best treatment effect with the least trauma,it is necessary for the surgeons to formulate detailed surgical strategies on the basis of strictly grasping the indications,and choose the operation according to their own clinical experience and skills,so as to maximize the advantages of different minimally invasive lumbar interbody fusion.

[Occurrence of rod fracture and salvage methods after primary surgery of the congenital lumbosacral deformity associated with sacral agenesis].

Objective: To analyze the occurrence of rod fracture after surgery for lumbosacral deformity associated sacral agenesis and discuss the relevant salvage methods. Methods: The clinical records of 19 patients who underwent surgical treatment for lumbosacral deformity associated sacral agenesis from January 2001 to January 2018 were retrospectively reviewed, including 11 boys and 8 girls. The average age was (9.6±5.2) years. The outcomes of surgical correction and internal fixation were evaluated by postoperative regular follow-up. We also recorded the time and position of rod fracture occurrence. The Cobb angle, coronal balance and sagittal balance were measured and compared to analyze the corresponding salvage methods and revision outcomes. Results: Three patients encountered rod fracture during follow-up, so the incidence of rod fracture after surgery for lumbosacral deformity associated sacral agenesis was 15.8%(3/19). Based on their own conditions, we formulated the individualized strategy and performed the revision surgery through the posterior-only approach. The most critical step was abundant bone-grafting and fusion in the defected sacroiliac joint. After revision, the scoliotic Cobb angle improved in two patients (91.5° vs 47.5°, 49.0° vs 28.0°) and coronal balance improved in one patient (40.3 mm vs 24.3 mm). No complication reoccurred during follow-up. Conclusion: The rod fracture after surgery for lumbosacral deformity associated sacral agenesis is quite common, which is probably correlated with its unique deformed structure and biomechanical characteristics. The individualized salvage methods and adequate bone-grafting and fusion for the defected sacroiliac joint will guarantee the reconstruction and maintenance of spine balance after revision.

[Changes of histopathological and hematological characteristics in recurrent chronic rhinosinusitis with nasal polyps].

Objective: To investigate the histopathological and hematological changes in reoperation of recurrent chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: A total of 41 patients with CRSwNP who underwent two consecutive endoscopic sinus surgeries in Peking Union Medical College Hospital from February 1999 to April 2019 were included retrospectively, including 25 males and 16 females, aged (40.7±13.6) years at the former surgery and (47.0±13.2) years at the recurrent surgery. The peripheral blood cell count results were collected. Differential inflammatory cells in nasal polyp tissue sections were counted and characteristics of tissue remodeling were scored. Paired t test was used to compare the hematological and histological data of the two surgeries in the same cohort. Spearman's rank correlation coefficient was used to determine the correlation between tissue and peripheral blood eosinophil contents. Results: In histopathological tissue sections of nasal polyps, the mean tissue eosinophil, lymphocyte and total inflammatory cell counts per high power field significantly decreased (54.04±34.67 vs 76.97±65.59, 35.27±16.61 vs 50.01±26.94, 128.88±41.32 vs 176.38±80.59, t value was 2.413, 2.923, 3.445, respectively, all P<0.05), whereas the percentages of different inflammatory cell types remained unchanged when comparing the recurrent surgery with the former surgery. There was a significant reduction of basement membrane thickness and goblet cell hyperplasia score in the recurrent surgery (1.29±0.84 vs 2.00±0.84, 1.81±1.31 vs 2.44±1.10, t value was 5.367, 2.714, respectively, all P<0.05). Subgroup analysis suggested that changes in asthmatic cases, younger cases and cases without previous surgery were more remarkable than non-asthmatics, older cases and cases with previous surgery, respectively. There was no significant change in peripheral white blood cell counts and differential cell percentages, except a small increase of blood monocyte percentage. Correlation analysis showed that tissue eosinophil content correlated positively with blood eosinophil content at each surgery. Conclusions: In the recurrent surgery of CRSwNP, tissue eosinophil, lymphocyte and total inflammatory cell counts decrease significantly compare with that of the former surgery. The histological inflammatory load decreases with improvement of tissue remodeling, which could be attributed to the integrated treatment with surgery and medications.

Bain and Nishiyama-Wassermann transition path separation in the martensitic transitions of Fe.

The importance of martensitic transformations has led to tremendous efforts to explore the microscopic martensitic transition paths. There are five possible transformation paths (for γ → α transition) known for Fe at present, and at an arbitrary activation energy, any of the five paths might be followed. It then becomes considerably difficult to monitor the microscopic phase transition mechanism in experiments. Therefore, it is helpful to realize only one of the paths in a physical process. Based on first-principles calculations, we show that at suitable activation energies the Nishiyama-Wassermann (N-W) transformation path can be realized without the involvement of the Bain path, since the condition E NW(θ) < E < E Bain can be satisfied by pure Fe. E is the activation energy of the system, and E NW(θ) and E Bain are the energy barriers for the N-W and Bain transformations, respectively. In particular, the potential energy surface (PES) for the N-W transformation has been calculated as being four-dimensional, i.e., E = E(a,b,c,θ), where (a, b, c) are the lattice constants and θ is the shear angle involved in the shear distortion of the N-W path.

[Comparison of clinical outcomes between type B and type C coronal pattern patients with degenerative scoliosis].

Objective: To investigate the differences of the radiographic and clinical outcomes after posterior correction surgeries between degenerative scoliosis (DS) patients with type B and type C coronal pattern. Methods: From March 2010 to August 2017, the clinical data of 38 patients (type B: 24; type C: 14) who were treated with posterior correction surgeries for DS were retrospectively reviewed. Radiographic parameters including Cobb angle of main curve, coronal imbalance (CI), lumbar lordosis (LL), global kyphosis (GK) and sagittal vertical axis (SVA) were measured on standing anteroposterior and lateral radiographs of the whole spine before and after surgery. Patient-reported outcomes were evaluated by using the visual analogue scale (VAS), the Oswestry disability index (ODI) and SF-36 questionnaire. The independent t-test was applied to compare the difference for statistical analysis. Results: There was no significant differences between the two groups in terms of age, gender, follow-up duration, preoperative curve magnitude, severity of CI, sagittal malalignment and surgical strategies (all P>0.05). In patients with type B coronal pattern, the main curve was corrected from 44°±19° before surgery to 19°±7° immediately after surgery (t=8.496, P<0.001) and to 19°±6° at the last follow-up (t=-0.657, P=0.518). In patients with type C coronal pattern, the main curve was corrected from 43°±9° before surgery to 21°±4° immediately after surgery (t=13.537, P<0.001) and to 21°±5° at the last follow-up (t=-0.186, P=0.856). No significant difference of Cobb angle of main curve was found between the two groups either before the operation or immediately post operation (all P>0.05). In addition, significant improvement of CI was observed after surgery in both groups and the correction was maintained well at the last follow-up. However, patients with type C coronal pattern had greater CI than that in those with type B coronal pattern immediately post operation (t=-2.401, P=0.022) and at the last follow-up (t=-2.659, P=0.012). At the last follow-up the scores of SF-36 questionnaire, ODI and VAS showed significant improvement in both groups (all P<0.05). Conclusion: Posterior correction surgery could provide remarkable radiographic and clinical outcomes in DS patients with type B and type C coronal pattern, and DS patients with type B coronal pattern could achieve a more satisfied coronal balance after surgery.

[Contrastive study of thumb ossification composite index and Risser sign in evaluating the growth potential of adolescent idiopathic scoliosis].

Objective: To compare and analyze the correlations between thumb ossification composite index (TOCI), Risser sign and digital skeletal age (DSA) scores and to verify the possibility of TOCI as a supplementary to Risser sign in the evaluation of growth potential of adolescent idiopathic scoliosis (AIS) patients. Methods: Forty-nine AIS patients undergoing bracing treatment between May 2006 and May 2014 were selected from Nanjing Drum Tower Hospital. The follow-up interval was 4-6 months. The following data at each visit were routinely collected, including TOCI and DSA scores, as well as chronologic age and standing height. The height velocity (HV) at each visit was calculated based on the above data. All results were analyzed by Spearman correlation with TOCI and Risser sign. Results: There were strong correlations between TOCI and Risser sign and DSA scores (r=0.962, 0.813, both P<0.01). In AIS patients whose Risser sign were 0-1, the correlation between TOCI and DSA scores was more pronounced, compared with the correlation between Risser sign and DSA scores (0.918 vs 0.792, P<0.01). The HV averaged (7.1±2.1) cm/year in TOCI 5, significantly larger than these in other TOCI scores (all P<0.01). Conclusions: The TOCI 5 can be a sign of high height velocity and high growth potential in AIS patients. TOCI is a valid indicator of skeletal maturity evaluation and can be used as a helpful supplementary to Risser sign, whose predictive ability may be better than Risser sign.

[Effect of Modic changes on fusion rate and cage subsidence after transforaminal lumbar interbody fusion].

Objective: To investigate the effects of Modic changes on the fusion rate and cage subsidence after transforaminal lumbar interbody fusion (TLIF). Methods: From January 2015 to January 2018, a total of 186 patients with degenerative lumbar disease who received lumbar instrumentation fusion and monosegmental TLIF with single polyetheretherketone (PEEK) cage in Nanjing Drum Tower Hospital were retrospectively reviewed. Patients with Modic changes at the level where the cage was placed were enrolled as Modic group, and the remaining were assigned into non-Modic group. Disk height, lumbar lordosis and segmental lordosis of the level with TLIF were measured based on the preoperative, postoperative and latest follow-up lateral radiograph. The fusion rate and cage subsidence (more than 2 mm on either endplate) were recorded based on CT scan at the latest follow-up. The Oswestry disability index (ODI) and visual analogue scale (VAS) of pain was used to evaluate the clinical outcome. The data were compared with paired t test between the two groups. Results: In this study, there were 70 males and 116 females with an average age of (55±13) years. There were 99 patients in the Modic group (25 with type 1, 66 with type 2, 8 with type 3), and 87 patients in the non-Modic group. There was no significant difference between Modic group and non-Modic group in demographics and postoperative radiographs. The patients were followed-up for (19±4) months (13 to 48 months). All patients achieved grade 1 or 2 fusion. Cage subsidence was detected in 34 patients (18.3%, 34/186). The incidence of subsidence in Modic group (24.2%, 24/99) was significantly higher than that in non-Modic group (11.5%, 10/87) (χ(2)=5.038, P<0.05), and the incidence of subsidence in type Ⅰ (28.0%, 7/25) and type Ⅱ (24.2%, 16/66) were higher than that in non-Modic group (11.5%, 10/87). There was no significant difference in ODI and VAS between Modic group and non-Modic group before and after the operation and at the latest follow-up (t=0.397-1.568, all P>0.05). Conclusion: Preoperative Modic changes have no impact on fusion rate after transforaminal lumbar interbody fusion, but both type Ⅰ and Ⅱ Modic changes do increase the risk of cage subsidence.

[Efficacy of sequential correction based on satellite rod techniquein degenerative scoliosis with B-type coronal imbalance].

Objective: To evaluate the radiographic and clinical outcomes of sequential correction based on satellite rod technique in degenerative scoliosis (DS) with B-type coronal imbalance, and to investigate the efficacy of sequential correction in this cohort. Methods: Twenty-one DS patients with B-type coronal imbalance applying sequential correction from December 2015 to July 2017 in Nanjing Drum Tower Hospital were retrospectively reviewed. There were 4 males and 17 females in this group, the average age was (63±8) years. The coronal parameters including Cobb angle of main curve and distance between C(7) plumb line and center sacral vertical line (C(7)PL-CSVL), as well as sagittal parameters including global kyphosis (GK) and sagittal vertical axis (SVA) were assessed pre-operatively, post-operatively and at the last follow-up. The Scoliosis Research Society-22 (SRS-22) questionnaire was fulfilled before the operation and at each follow-up to evaluate the quality of life. Paired t test was performed for statistical analysis. Results: The patients were followed-up for (20±8) months. The post-operative Cobb angle of main curve was significantly improved from 52°±12° to 19°±7° (t=13.886, P<0.01), and it was 19°±8° at the last follow-up and no significant correction loss was attained (t=1.101, P=0.284). The values of C(7)PL-CSVL before the operation, after the operation and at the final follow-up were (46±11) mm, (12±7) mm and (12±7) mm, respectively; significant post-operative improvement achieved (t=19.718, P<0.01) while there was no correction loss at last follow-up (t=-1.393, P=0.179). After sequential correction, 20 patients (95.2%) improved to A-type coronal imbalance while 1 patient (4.8%) remained with B-type coronal imbalance. Significant post-operative improvements were found in terms of GK and SVA and no significant correction loss was found during follow-up. The scores of pain and self-image showed significant improvement at the last follow-up (t=8.706, 3.104, both P<0.01). In addition, there was no implant failure during follow-up. Conclusion: The sequential correction based on satellite rod technique in DS patients with B-type coronal imbalance corrects the deformity, relieves the clinical symptoms, improves the quality of life, and decreases the rates of post-operative coronal imbalance as well as implant-related complications.

[One-stage posterior correction and second-stage anterior debridement and fusion in treating children with thoracic tuberculosis complicated with kyphoscoliosis].

Objective: To investigate the clinical outcomes of one-stage posterior correction surgery and second-stage anterior debridement and fusion in treating children with thoracic tuberculosis complicated with kyphoscoliosis. Methods: From January 2008 to December 2014, a total of 17 children with thoracic vertebral tuberculosis complicated with kyphoscoliosis who underwent a one-stage posterior correction and second-stage anterior debridement and complementary fusion were included. There were 8 males and 9 females with an average age of (8±4) years (5-14 years). All patients underwent posterior correction and anterior debridement and bone graft fusion surgery. The neurological function was determined by Frankel grade. The operation time, estimated blood loss (EBL), levels fused and numbers of screws were recorded. The following radiographic parameters were measured: Cobb angle of the coronal curve, regional kyphosis and sagittal vertical axis (SVA). The incidence of intraoperative and postoperative complications was recorded. The data before and after the operation were compared with paired sample t test. Results: The tuberculosis lesions located in the thoracic vertebrae, and the abscess involved 2 to 4 vertebral segments. The average operation time was (4.1±0.8) h, the EBL was (526±275) ml, the levels fused were 7.6±2.3, and 173 pedicle screws were placed. The preoperative coronal curve averaged 12.6°±6.2°, and it was corrected to 4.2°±1.9° postoperatively (t=4.628, P<0.01), the regional kyphosis was 67.2°±19.4°, and it was corrected to 15.7°±8.2° postoperatively (t=8.192, P<0.01). The SVA improved from (8.1±5.0) mm to (3.0±1.7) mm postoperatively. The mean duration of follow-up for all the patients were (38±11) months. At final follow-up, SVA was reduced to (2.4±2.0) mm and the other parameter kept stable. Thirteen patients had more than one grade improvement of Frankel grade. The VAS score for all patients improved from 4.7±2.8 to 2.2±0.5 postoperatively (t=3.973, P=0.01), and improved to 0.5±0.5 at final follow-up (t=-7.880, P<0.01). No recurrence of primary spinal tuberculosis was seen at final follow-up of all patients. Conclusions: One-stage posterior correction and second-stage anterior complementary debridement and fusion is an effective procedure for children with thoracic tuberculosis complicated with kyphoscoliosis. Significant postoperative deformity correction could be achieved with satisfactory improvement of neurological function. Solid fusion and satisfactory correction maintenance were observed at mid-to long-term follow-up.