The Comparison of Posterior Intervertebral Release Combined with Posterior Column Osteotomy and Posterior Column Osteotomy Alone for the Treatment of Moderate-to-Severe Rigid Scoliosis: A Prospective Controlled Study.

OBJECTIVES: There is no consensus on the treatment of moderate-to-severe rigid scoliosis. Anterior release and three-column osteotomy are excessively traumatic, whereas posterior column osteotomy (PCO) alone results in poor outcomes. An emerging surgical technique, posterior intervertebral release (PR), can release the rigid spine from the posterior approach. This study was performed to compare the multi-segment apical convex PR combined with PCO and PCO alone in patients with moderate-to-severe rigid scoliosis. METHODS: From June 2021 to June 2022, this prospective study of moderate-to-severe (Cobb: 70-90°) rigid scoliosis (flexibility of main curve <25%) involved two groups defined by surgical procedure: the PR group, the patients undergoing PR combined with PCO; and the PCO group, the patients undergoing PCO alone. Follow-up was at least 12 months. Radiographic results mainly included main curve Cobb, correction of per PR/PCO segment, apical vertebra rotation (AVR) and apical vertebra translation (AVT). Demographics, surgical data, complications were also recorded. Student's independent samples t test and Pearson's chi-square test were used to compare the differences between groups. RESULTS: Forty patients with an average age of 16.65 years were included (PR group, n = 20; PCO group, n = 20). The main curves averaged 77.56° ± 5.86° versus 78.02° ± 5.72° preoperatively and 20.07° ± 6.73° versus 33.58° ± 5.76° (p < 0.001) at the last follow-up in the PR and PCO groups, respectively. The mean correction rates were 74.30% and 56.84%, respectively (p < 0.001). The average coronal curve correction was 13.49° per release segment, which was significantly higher than the PCO correction of 6.20° (p < 0.001). The correction of apical vertebra rotation and translation in the main thoracic curve was significantly better in the PR group than in the PCO group (p < 0.05). Several minor complications in the two groups improved after conservative treatment. CONCLUSION: The multi-segment apical convex PR combined with PCO offers more advantages than PCO alone in the treatment of patients with moderate-to-severe rigid scoliosis. Owing to its excellent corrective effect and few complications, this is a high benefit-risk ratio surgical strategy for rigid scoliosis.

Lumbar Disc Herniation with Contralateral Symptoms: A Case-Series of 11 Patients and Literature Review.

OBJECTIVE: Lumbar disc herniation (LDH) is a common pathology that typically causes unilateral radiculopathy on the same side as herniation, while patients may occasionally present with contralateral symptoms. Owing to the rare incidence of LDH with contralateral symptoms, the pathological mechanism remains unclear and the optimal surgical strategy is a subject of debate. This study aimed to provide new insights into the pathological mechanism of contralateral symptoms and assess the efficacy of ipsilateral hemilaminectomy and discectomy surgery in this population. METHODS: This study was a retrospective, single-center, clinical case series, including 11 LDH cases with exclusive contralateral symptoms. We searched for LDH cases that were presented at our institution between January 2011 and December 2020. Adult LDH Patients with contralateral radicular pains were included, while those with ipsilateral radiculopathy, lumbar stenosis, foraminal stenosis on the symptomatic side, multilevel disc herniations, scoliosis, and lumbar operation history were excluded. Visual Analog Scale (VAS), clinical features, radiographic images, and other data were collected from the study cohort of 11 cases for further analysis. We also reviewed LDH cases in English literature from 1978 to 2023 to analyze their clinical characteristics and treatment. RESULTS: The incidence rate of LDH with contralateral symptoms in single-level LDH cases was 0.32%. The average age of our 11 cases was 49.3 years old, and five of them were female (45.5%). All individuals had single-level lateral LDH, with six cases (54.5%) located at L4-5 and five cases (45.5%) located at L5-S1. Upon admission, patients presented with lower back pain (seven cases, 63.6%), radicular pain (seven cases, 63.6%), hypoesthesia (seven cases, 63.6%), and muscle weakness (one case, 9.1%) on the contralateral side alone. Each case experienced ipsilateral hemilaminectomy and discectomy, and no lateral recess stenosis, hypertrophy of facets or ligaments, and sequestrated discs were found during surgery. All of them have good pain relief with two cases reporting no pain and nine cases reporting only mild pain at the last follow-up. CONCLUSIONS: Based on the surgical findings of our 11 LDH cases with contralateral symptoms, we hypothesized that the contralateral symptoms might be produced when the nerve root on the contralateral symptomatic side was tightly pulled by the herniated disc via the dural mater. Ipsilateral hemilaminectomy and discectomy surgery effectively and efficiently relieve the symptoms without postoperative complications for these patients.

The Effect of Halo-Pelvic Traction on Bone Mineral Density of Vertebrae and Corresponding Risk Factors.

OBJECTIVES: Decreased bone mineral density (BMD) is associated with complications in implantation surgery for severe spinal deformity. In this quantitative study, we aimed to investigate the impact of halo-pelvic traction on vertebral bone mineral density (BMD) and identify the risk factors for a decrease in BMD. METHODS: Patients who underwent halo-pelvic traction at our hospital between 2019 and 2022 were included in the study. Patients' data, including height, weight, and BMD pre- and post-traction, were collected and analyzed. Quantitative computed tomography (QCT) was used to determine the BMD. The paired rank sum test was used to evaluate the changes in each measurement parameter. Linear regression was used to identify risk factors for a decrease in BMD. RESULTS: Fifteen patients were included in the study, nine women and six men, with an average age of 21.2 ± 7.3 years. Eleven patients had severe rigid scoliosis, while four had tuberculotic kyphosis. One expert measured the BMD values of 345 vertebrae using QCT. The average traction time was 143.3 ± 44.4 days. The average pre-traction BMD was 183.1 ± 73.8 mg/cm3 , and the average post-traction BMD was 140.5 ± 61.3 mg/cm3 (p < 0.01) Patients' height increased from an average of 151.3 ± 12.8 cm pre-traction to 165.5 ± 13.7 cm post-traction (p < 0.01), with traction length averaging 14.3 ± 6.2 cm (p < 0.01). The Cobb angle of the main curve declined from an average of 112.5° ± 24.4° pre-traction to 67.7° ± 19.8° post-traction (p < 0.01). Linear regression revealed a positive correlation between BMD loss and traction length and a negative correlation between BMD loss and correction rate. CONCLUSIONS: Halo-pelvic traction can lead to a decrease in the BMD of the spinal vertebrae, with traction length positively correlated with BMD loss and correction rate negatively correlated with BMD loss. To prevent osteoporosis, physicians should ensure a limited traction length while utilizing better management techniques.

Long-term outcomes of the nano-hydroxyapatite/polyamide-66 cage versus the titanium mesh cage for anterior reconstruction of thoracic and lumbar corpectomy: a retrospective study with at least 7 years of follow-up.

BACKGROUND: The nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a biomimetic cage with a lower elastic modulus than the titanium mesh cage (TMC). This study aimed to compare the long-term outcomes of the n-HA/PA66 cage and TMC in the anterior reconstruction of thoracic and lumbar fractures. METHODS: We retrospectively studied 113 patients with acute traumatic thoracic or lumbar burst fractures, comprising 60 patients treated with the TMC and 53 treated with the n-HA/PA66 cage for anterior reconstruction following single-level corpectomy. The radiographic data (cage subsidence, fusion status, segmental sagittal alignment) and clinical data (visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) for function) were evaluated preoperatively, postoperatively, and at final follow-up after a minimum 7-year period. RESULTS: The n-HA/PA66 and TMC groups had similar final fusion rates (96.2% vs. 95.0%). The cage subsidence at final follow-up was 2.3 ± 1.6 mm with subsidence of more than 3 mm occurring in 24.5% in the n-HA/PA66 group, which was significantly lower than the respective values of 3.9 ± 2.5 mm and 58.3% in the TMC group. The n-HA/PA66 group also had better correction of the bisegmental kyphotic angle than the TMC group (7.1° ± 7.5° vs 1.9° ± 8.6°, p < 0.01), with lower loss of correction (2.9° ± 2.5° vs 5.2° ± 4.1°, p < 0.01). The mean ODI steadily decreased after surgery in both groups. At final follow-up, the ODI and VAS were similar in the TMC and n-HA/PA66 groups. CONCLUSIONS: The n-HA/PA66 cage is associated with excellent radiographic fusion, better maintenance of the height of the fused segment, and better correction of kyphosis than the TMC during 7 years of follow-up after one-level anterior corpectomy. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to the TMC in anterior reconstruction of thoracic or lumbar fractures.

Multiple Hemivertebrae: The Natural History and Treatment of 50 Patients.

OBJECTIVE: Multiple hemivertebrae (MHV) is defined as three or more hemivertebrae, and is relatively uncommon among patients with congenital scoliosis. This study aimed to compare the natural history of different kinds of MHV and describe the surgical outcome of MHV. METHODS: In this retrospective cohort study, a total of 50 patients diagnosed with MHV were enrolled from June 2007 to June 2018. The medical records and radiographs of these patients were reviewed to summarize the characteristics of MHV. Patients with MHV were divided into the unbalanced (UB) group, partially unbalanced (PUB) group, and completely balanced (CB) group. Medical records and radiographs of MHV patients were reviewed to collect HV position, natural history, coronal and sagittal parameters. A Mann-Whitney U test was used to compare the radiographical data, such as the cobb angle of main curve and secondary curve, and Fisher's exact test was used to compare the patients in different kinds of MHV with surgical indication or not. RESULTS: The average number of hemivertebrae was 3.6 and the average main curve was 57.5°. Twenty-four of 50 patients had associated anomalies, including four patients with sacral agenesis, one with tetralogy of Fallot, two with congenital imperforate anus, and 17 with Klippel-Feil syndrome. In 22 patients who underwent MRI imaging, three patients had mild syringomyelia and three patients had diastematomyelia. The UB and PUB groups had a larger main curve and compensatory curve than the CB group. Of the 25 patients with follow-up before surgery, the curve progression rate was highest in the UB group (12.1°/year) but similar in the PUB group (4.2°/year) and CB group (3.6°/year). All patients in the UB and PUB group met the criteria for surgery. In contrast, only 10 of 23 patients in the CB group had surgical indications. Eighteen of the 37 patients with surgical indications chose to undergo surgery and the correction rate of the main curve was 51.4%. CONCLUSIONS: Early surgical intervention should be considered for most patients with UB or PUB MHV. For patients with CB MHV, surgical treatment may not be urgently needed at the first visit. Posterior hemivertebrectomy could be used for the treatment of MHV with satisfying radiographic outcome.

Lentivirus-shRNA Mediated Prolyl Hydroxylase 2 Knockdown Increases HIF-1α and Inhibits Nucleus Pulposus Cells Degeneration.

Hypoxia-inducible factor (HIF) plays a crucial role in regulating the hypoxia-inducible state of nucleus pulposus cells in the intervertebral disc. In addition, the oxygen-dependent conversion of HIF-1α in nucleus pulposus cells is controlled by the protein proline 4-hydroxylase domain (PHD) family. To explore whether HIF-1α can be regulated by modulating PHD homologs to inhibit nucleus pulposus degeneration, PHD2-shRNAs were designed and a PHD2 interference vector was constructed. The expression of HIF-1α and PHD2 genes in the nucleus pulposus cells in the experimental group was detected by RT-PCR, and the expression of HIF-1α, MMP-2, Aggrecan, and Col II proteins in the P0-P3 cells in the experimental group and the control group was detected by Western blotting. The apoptosis of P0-P3 nucleus pulposus cells was detected by flow cytometry. After lentivirus infection, the interference efficiency of the PHD2 gene decreased with cell passage. The apoptosis of P1-P3 cells in the experimental group was significantly lower than that in the control group or degeneration group. Compared to the control group, the expression of HIF-1α, Aggrecan, and Col II proteins increased significantly, and the expression of MMP-2 protein decreased significantly. In conclusion, interference with PHD2 can upregulate the expression of HIF-1α, accelerate anabolism, reduce catabolism, inhibit apoptosis of nucleus pulposus cells, and then these can inhibit degeneration of nucleus pulposus cells. Our results can provide an effective therapeutic target in intervertebral discs during intervertebral disc degeneration, and this may have important clinical significance.

Transplantation of NEP1-40 and NT-3 Gene-Co-Transduced Neural Stem Cells Improves Function and Neurogenesis after Spinal Cord Injury in a Rat Model.

Background: Spinal cord injury (SCI) generally results in necrosis, scarring, cavitation, and a release of inhibitory molecules of the nervous system, which lead to disruption of neurotransmission and impede nerve fiber regeneration. This study was intended to evaluate the therapeutic efficacy rates of the transplantation of NEP1-40- and NT-3 gene-co-transduced neural stem cells (NSCs) in a rat model of SCI. Methods: Ninety Sprague-Dawley rats were subdivided randomly into six groups: sham-operated, SCI model, SCI + NSCs-NC, SCI + NEP1-40-NSCs, SCI + NT-3-NSCs, and SCI + NEP1-40/NT-3-NSCs. Motor function at different time points was evaluated using the Basso, Beattie, and Bresnahan locomotor activity scoring system (BBB). At 8 weeks post-transplantation, histological analysis, a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, immunofluorescent assay, immunocytochemical staining, and cholera toxin subunit B (CTB) retrograde tracing were performed. Results: BBB scores of the co-transduction group significantly surpassed those of other transplantation groups and of the SCI-model group after 2 weeks post-transplantation. The apoptotic rate of neurocytes was significantly lower in the co-transduction group than in other experimental groups. Expression of NF-200, MBP, and ChAT was significantly higher in the SCI + NEP1-40/NT-3-NSCs group than in other transplantation groups, whereas the expression of GFAP and GAD67 was the second lowest after the sham-operated group. CTB retrograde tracing showed that CTB-positive neural fibers on the caudal side of the hemisected site were more numerous in the SCI + NEP1-40/NT-3-NSCs group than in other experimental groups. Conclusion: Transplantation of NEP1-40- and NT-3-gene-co-transduced NSCs can modify the protein expression following acute SCI and promote neuron formation and axonal regeneration, thus having a neuroprotective effect. Furthermore, this effect surpasses that of transplantation of single-gene-transduced NSCs. Transplantation of NEP1-40- and NT-3-gene-co-transduced NSCs is effective at the neural recovery of the rat model of SCI and may be a novel strategy for clinical treatment of SCI.

Postoperative proximal junctional kyphosis correlated with thoracic inlet angle in Lenke 5c adolescent idiopathic scoliosis patients following posterior surgery.

BACKGROUND: Proximal junctional kyphosis is a common complication after posterior fusion in patients with adolescent idiopathic scoliosis and is correlated with postoperative changes of thoracic kyphosis. In lenke 5c patients, higher postoperative LL and spontaneous change of TK may produce an effect on final PJK. However, no studies has been performed to evaluate the correlation of PJK with thoracocervical parameters in patients with AIS. METHODS: Data from 98 patients who underwent posterior fusion for Lenke 5C AIS with 2 years of follow-up were retrospectively reviewed. Patients in the extended fusion group underwent fusion at levels higher than upper-end vertebra + 2 (n = 38), and those in the thoracolumbar/lumbar (TL/L) fusion group underwent fusion at UEV + 2 or lower (n = 60). RESULTS: During an average follow-up of 38.1 months, 23 of 98 patients developed PJK. The extended fusion group had a higher incidence of PJK than the TL/L fusion group (14/38 vs. 9/60, respectively; P = 0.01) and a significantly greater decrease in thoracic kyphosis than the TL/L group (P < 0.01). Patients with PJK had a significantly larger preoperative thoracic inlet angle (TIA) than those without PJK (P < 0.01). Multivariate analysis showed that a greater preoperative TIA and extended fusion were associated with PJK. The Scoliosis Research Society 22-item questionnaire score did not significantly differ between the PJK and non-PJK groups. CONCLUSIONS: The preoperative TIA could be a predictor of PJK. Among patients with Lenke 5C AIS, those with a TIA of > 71° are more likely to develop PJK. Additionally, extended fusion in patients with Lenke 5C may increase the risk of PJK.

As above, so below? The influence of leader humor on bootleg innovation: The mechanism of psychological empowerment and affective trust in leaders.

Leadership humor is widely used in management practice and has aroused extensive discussion in academia. On account of the two-sided influence of leader humor on employees, its double-edged sword effect on employee behavior has been put more emphasis. As a benign violation of organizational norms and a kind of pro-organizational violation, respectively, both Leadership humor and employee bootleg innovation have the characteristics of violating organizational norms, but few studies have examined the relationship between them. Based on benign violation theory and social cognition theory, this study conducted a two-stage questionnaire survey and statistical-econometric analysis of 324 employees in 23 IT and manufacturing technology companies in Guangdong, Jiangsu, Zhejiang, Hubei, Beijing, and Shanghai, China. It not only examined the relationship between leadership humor and employee bootleg innovation but also tested a moderated mediation model. Results show that leadership humor is positively correlated with psychological empowerment and employee bootleg innovation, namely, leadership humor indirectly and positively affects employee bootleg innovation through psychological empowerment. Moreover, the indirect effect is positively regulated by leadership emotional trust. The higher the emotional trust of employees to leadership, the stronger the mediating role of psychological empowerment between leader humor and bootleg innovation behavior. The study enriches the existing path of research on the double-edged impact of leader humor on employee behavior, expands the boundary conditions of the relationship between empowered cognitive mediation and employee bootleg innovation and provides enlightenments for Chinese leaders to effectively apply the tool of leader humor.

Inhibition of PARP Potentiates Immune Checkpoint Therapy through miR-513/PD-L1 Pathway in Hepatocellular Carcinoma.

Background: The DNA repair enzyme poly(ADP-ribose) polymerase (PARP) is involved in DNA damage repair and cell death. However, the association between PARP's biological activities and the immune microenvironment in hepatocellular carcinoma (HCC) is unclear. The present study will explore whether combining a PARP inhibitor with anti-PD1 might improve the anti-HCC impact and explain how it works. Method: The PARP inhibitor olaparib was screened out of 867 drugs through Cell Counting Kit 8 (CCK-8) assay. The expression of PARP was verified through the TCGA and TISIDB databases. The impacts exerted by PARP inhibitor olaparib to HCC cells were assessed via wound healing, Transwell, and proliferation assay. In vivo, experiments were performed in a C57BL/6 mouse model to evaluate the function of PARP inhibitor olaparib combination with anti-PD1 in HCC and mice tumors were further detected by immunohistochemically staining. Result: Olaparib was selected as the research object on the basis of drug screening. The results of the TCGA and Human Protein Atlas databases revealed that PARP was significantly upregulated in carcinoma cell cluster of HCC tissues compared to normal tissues. Higher expression of PARP showed a poorer prognosis based on Kaplan-Meier Plotter. qRT-PCR experiments confirmed that olaparib could increase PD-L1 expression through inhibiting miR-513 in HCC cells. In vivo, experiment confirmed that the combination of olaparib and anti-PD1 could enhance the immunotherapy effect of HCC. Conclusion: The present study reveals that inhibition of PARP potentiates immune checkpoint therapy through the miR-513/PD-L1 pathway in HCC and the combination of PARP inhibitor olaparib and anti-PD1 is beneficial to HCC therapy.

Nomogram for predicting the distal adding-on phenomenon in severe and rigid scoliosis.

Background: The distal adding-on phenomenon has attracted extensive discussion in the field of spine surgery due to the continual occurrence after scoliosis correction. Previous work has mainly focused on adolescent idiopathic scoliosis (AIS), and a relatively high number of theories for the mechanism of the distal adding-on phenomenon has been proposed for these kinds of patients. Severe and rigid scoliosis, as a special disease form, has a unique etiology, clinical manifestations and internal mechanisms distinct from those of AIS. Given the uniqueness of this disease, the mechanism and causes of the distal adding-on phenomenon have been infrequently studied in depth. Objective: To define clinical and radiological factors associated with distal adding-on in patients with severe and rigid scoliosis. Methods: Radiographic parameters and demographic data of patients with severe and rigid scoliosis were evaluated preoperatively, after posterior instrumentation and fusion surgery, and at the final follow-up via radiographs. According to the appearance of distal adding-on at the final follow-up, the patients were grouped into the Adding-on and the Non-adding-on groups. Various radiological parameters were analyzed in stepwise multivariate logistic regression to identify the variables associated with distal adding-on, which were then incorporated into a nomogram. The predictive performance and calibration of the nomograms for distal adding-on were assessed using C statistics and calibration plots. Results: 93 patients (21 in the Adding-on and 72 in the Non-adding-on group) were included. The incidence of distal adding-on was 22.6%. The variables associated with distal adding-on were the anterior release, posterior internal distraction, and later posterior spinal fusion (IP) procedure, the posterior vertebral column resection and posterior spinal fusion (PVCR) procedure, postoperative apical vertebral translation (Post-AVT) and preoperative slope of the line linking the pedicles on the concave side of the upper- and lower-end vertebrae (Tan α). Combining these factors, the nomogram achieved a concordance index of 0.92 in predicting distal adding-on and had well-fitted calibration curves. Conclusions: For patient with a negative Tanα in severe and rigid scoliosis, the risk of distal adding-on tended to increase, and it is recommended to give priority to IP or PVCR. In the final correction, a smaller Post-AVT should not be pursued excessively.

Clinical algorithm for preventing missed diagnoses of occult cervical spine instability after acute trauma: A case report.

BACKGROUND: Missed or delayed diagnosis of cervical spine instability after acute trauma can have catastrophic consequences for the patient, resulting in severe neurological impairment. Currently, however, there is no consensus on the optimal strategy for diagnosing occult cervical spine instability. Thus, we present a case of occult cervical spine instability and provide a clinical algorithm to aid physicians in diagnosing occult instability of the cervical spine. CASE SUMMARY: A 57-year-old man presented with cervical spine pain and inability to stand following a serious fall from a height of 2 m. No obvious vertebral fracture or dislocation was found at the time on standard lateral X-ray, computed tomography, and magnetic resonance imaging (MRI). Subsequently, the initial surgical plan was unilateral open-door laminoplasty (C3-7) with alternative levels of centerpiece mini-plate fixation (C3, 5, and 7). However, the intraoperative C-arm fluoroscopic X-rays revealed significantly increased intervertebral space at C5-6, indicating instability at this level that was previously unrecognized on preoperative imaging. We finally performed lateral mass fixation and fusion at the C5-6 level. Looking back at the preoperative images, we found that the preoperative T2 MRI showed non-obvious high signal intensity at the C5-6 intervertebral disc and posterior interspinous ligament. CONCLUSION: MRI of cervical spine trauma patients should be carefully reviewed to detect disco-ligamentous injury, which will lead to further cervical spine instability. In patients with highly suspected cervical spine instability indicated on MRI, lateral X-ray under traction or after anesthesia and muscle relaxation needs to be performed to avoid missed diagnoses of occult cervical instability.

Proximal junctional kyphosis in Lenke 5 AIS patients: the important factor of pelvic incidence.

BACKGROUND: The purpose of the study was to investigate whether pelvic incidence (PI) will affect the occurrence of PJK in Lenke 5 AIS patients after correction surgery and try to explore a better surgical scheme based on PI. METHODS: Lenke 5C AIS patients that underwent correction surgery with a minimum of a 2-year follow-up were identified. Demographic and radiographic data were collected preoperatively, postoperatively, and at the final follow-up. The comparison between the PJK and the Non-PJK group was conducted and the subgroup analysis was performed based on the preoperative value of PI to investigate the potential mechanism of PJK. Clinical assessments were performed using the Scoliosis Research Society (SRS)-22 questionnaire. RESULTS: The mean preoperative Cobb angle of the TL/L curve was 53.4°±8.6. At the final follow-up, the mean TL/L Cobb angle was drastically decreased to 7.3°±6.8 (P < 0.001). The incidence of PJK in Lenke 5 AIS was 18.6 %, 21.9 % (7/32) in the low PI group (PI < 45°) and 15.8 % (6/38) in the high PI group (PI ≥ 45°), and there was no statistical difference between the two groups (χ2 = 0.425, P = 0.514). For low PI patients, there is no significant difference where the UIV is located with regards to the TK apex between the PJK and Non-PJK subgroups (χ2 = 1.103, P = 0.401). For high PI patients, PJK was more likely to occur when UIV was cephalad to than caudal to the TK apex (31.25 % vs. 4.7 %, P = 0.038). There was no significant difference in the selection of LIV between the two groups. CONCLUSIONS: There is no difference in the incidence of PJK between the Lenke 5 AIS patients with low PI (< 45°) and high PI (≥45°), but the main risk factor of PJK should be different. For patients with low PI, overcorrection of LL should be strictly avoided during surgery. For patients with high PI, the selection of UIV should not be at or cephalad to the apex of thoracic kyphosis to retain more mobile thoracic segments.

A novel posterior multiple screws distraction reducer system versus anterior release, posterior internal distraction, and subsequent spinal fusion for severe scoliosis.

PURPOSE: We previously reported anterior release, posterior internal distraction, and subsequent spinal fusion (ARPIDF) for the correction of severe scoliosis with a satisfactory correction rate. However, surgical procedures were completed in 2-3 stages. Here we compare Cobb angle of ≥90° in scoliosis correction between a novel posterior multiple screws distraction reducer (MSDR) system and ARPIDF. METHODS: Thirty-six patients with severe scoliosis treated by MSDR or ARPIDF (n = 18 in both groups). We retrospectively analyzed and compared outcome measures between the two groups over a minimum follow-up duration of 2 years. The following variables were compared between the two groups: age at surgery, sex, etiology, flexibility of the main thoracic curve, number of fused segments and screws, operation time, estimated blood loss, hospitalization time, follow-up duration, various radiological parameters, complication rate, and Scoliosis Research Society-30 score. RESULTS: There were no significant between-group differences with respect to age, sex, etiology, flexibility of the main thoracic curve, number of fused segments and screws, and follow-up duration. Further, there was no significant difference in terms of preoperative, postoperative, and final follow-up findings of the radiographic data. However, the ARPIDF group had longer operation and hospitalization times and greater blood loss. In the ARPIDF group, 4 patient developed complications (infection, intraoperative neuromonitoring changes, transient dyspnea); none of these events occurred in the MSDR group. CONCLUSION: The use of MSDR helped achieve greater scoliosis correction with a shorter operation time, lower blood loss, and lower complication rate than the use of ARPIDF. MSDR facilitates safer and easier correction of severe scoliosis without increasing surgical risk.

Predictive ability of pharyngeal inlet angle for the occurrence of postoperative dysphagia after occipitocervical fusion.

BACKGROUND: PIA has been proven to be a predictor for postoperative dysphagia in patients who undergo occipitospinal fusion. However, its predictive effect for postoperative dysphagia in patients who undergo OCF is unknown. The aim of this study was to evaluate the predictive ability of the pharyngeal inlet angle (PIA) for the occurrence of postoperative dysphagia in patients who undergo occipitocervical fusion (OCF). METHODS: Between 2010 and 2018, 98 patients who had undergone OCF were enrolled and reviewed. Patients were divided into two groups according to the presence of postoperative dysphagia. Radiographic parameters, including the atlas-dens interval (ADI), O-C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa), C2 tilting angle (C2Ta), C2-7 angle (C2-7a), PIA and narrowest oropharyngeal airway space (nPAS), were measured and compared. Simple linear regression and multiple regression analysis were used to evaluate the radiographic predictors for dysphagia. In addition, we used PIA = 90° as a threshold to analyze its effect on predicting dysphagia. RESULTS: Of the 98 patients, 26 exhibited postoperative dysphagia. Preoperatively, PIA in the dysphagia group was significantly higher than that in the nondysphagia group. We detected that O-C2a, O-EAa, PIA and nPAS all decreased sharply in the dysphagia group but increased slightly in the nondysphagia group. The changes were all significant. Through regression analyses, we found that PIA had a similar predictive effect as O-EAa for postoperative dysphagia and changes in nPAS. Additionally, patients with an increasing PIA exhibited no dysphagia, and the sensitivity of PIA <90° in predicting dysphagia reached 88.5%. CONCLUSIONS: PIA could be used as a predictor for postoperative dysphagia in patients undergoing OCF. Adjusting a PIA level higher than the preoperative PIA level could avoid dysphagia. For those who inevitably had decreasing PIA, preserving intraoperative PIA over 90° would help avert postoperative dysphagia. TRIAL REGISTRATION: This trial has been registered in the Medical Ethics Committee of West China Hospital, Sichuan University. The registration number is 762 and the date of registration is Sep. 9 th, 2019.

Loss of Correction After Removal of Spinal Implants in Congenital Scoliosis.

BACKGROUND: Previous studies have reported the progression of deformity in patients with adolescent idiopathic scoliosis after implant removal. However, for patients with congenital scoliosis, few studies have investigated the prognosis after implant removal. METHODS: We observed 24 patients with congenital scoliosis, who underwent implant removal, for at least 3 years. Radiographic parameters and demographic data were compared to evaluate whether implant removal would lead to deformity progression. RESULTS: Four of the 24 patients (16.7%) suffered correction loss and underwent revision surgery (RS). All correction losses occurred within 12 months of implant removal. The average curve of fixed segments (9.84° ± 7.22° to 16.42° ± 16.79°; P = 0.017) and kyphosis of fixed segments (10.46° ± 13.42° to 18.98° ± 25.99°; P = 0.03) increased significantly throughout the follow-up. After excluding patients who underwent RS, the changes in curve of fixed segments (9.10°-11.58°) and kyphosis of fixed segments (8.50°-9.24°) were all within the measurement error. The coronal and sagittal balance maintained during the follow-up. Through comparison, we thought that the younger age and lower Risser's grade with larger scoliosis might be risk factors for correction loss. CONCLUSIONS: Implant removal after fusion surgery for congenital scoliosis may present loss of correction and require RS, thus preserving implants is recommended. When removal of instrumentation is inevitable, parents and patients should be counseled for potential loss of correction and RS, and patients should be monitored for the progression of deformity.

A case report of severe degenerative lumbar scoliosis associated with windswept lower limb deformity.

BACKGROUND: The windswept lower limb deformity describes valgus deformity in one leg with varus deformity in the other. It is mostly seen in young children with metabolic bone diseases (such as rickets) and may lead to leg length discrepancy (LLD) and Degenerative scoliosis (DS) in older age. To the best of our knowledge, there was no report of the spinal surgery in patient with severe DS associated with windswept deformity. The objective of this study is to report the unique case of a 60-year-old woman with severe degenerative scoliosis (DS) associated with windswept deformity caused by rickets who underwent a posterior correction and fusion surgery in spine. CASE PRESENTATION: The patient was diagnosed as rickets windswept lower limb deformity for 50 years but never went through routine treatment. Then, she performed lumbar scoliosis for more than 20 years and suffered from severe back pain for 4 years. After overall clinical evaluation and radiographic measures, we performed a posterior surgical correction and fusion from T9-L5. With this surgery, the main thoracolumbar curve Cobb angle corrected from 72.5° to 21.0°, the coronal balance from 0 cm to 2.0 cm while the sagittal vertical axis (SVA) from 1.5 cm to - 1.0 cm. At 2 years postoperative follow-up, her back pain has almost completely relieved with a satisfied fixation and bone fusion showed on CT scans. However, a coronal imbalance was found with C7-CSVLdistance equal to 4.0 cm. This coronal imbalance was highly correlated to the untreated LLD and pelvic obliquity, and should be improved by standing posture or shoe lifts. CONCLUSIONS: For such patient, the pure spinal correction and fusion surgery, in spite of lower limbs deformity, can achieve good relieve of back pain symptom, however may accompany by the complication of coronal imbalance due to the unimproved pelvic obliquity and LLD. However, longer follow-up is necessary to observe the long-term outcome of this patient's postoperative coronal imbalance.