[Long-term Survival in Hospitalized Patients with Lung Cancer among Peasants 
in the Coal-producing Area in Eastern Yunnan, China].

BACKGROUND: Xuanwei and Fuyuan are rural counties, located in the late Permian coal poly area of eastern Yunnan and western Guizhou, where lung cancer mortality rates are among the highest in the China, with similarity for both men and women, younger age at diagnosis and death, and higher in rural areas than in urban areas. In this paper, long-term follow-up of lung cancer cases in local peasants was conducted to observe their survival prognosis and its influencing factors. METHODS: Data of patients diagnosed with lung cancer from January 2005 to June 2011, who had lived in Xuanwei and Fuyuan counties for many years, were collected from 20 hospitals at the local provincial, municipal and county levels. To estimate survival outcomes, individuals were followed up until the end of 2021. The 5-year, 10-year and 15-year survival rates were estimated using the Kaplan-Meier method. Survival differences were examined with Kaplan-Meier curves and Cox proportional hazards models. RESULTS: A total of 3,017 cases were effectively followed up (2,537 peasants and 480 non-peasants). The median age at diagnosis was 57 years, and the median follow-up time was 122 months. During the follow-up period, 2,493 cases (82.6%) died. The distribution of cases by clinical stage was as follows: stage I (3.7%), stage II (6.7%), stage III (15.8%), stage IV (21.1%) and unknown stage (52.7%). Treatment at the provincial, municipal and county-level hospitals accounted for 32.5%, 22.2% and 45.3%, respectively, and surgical treatment was performed in 23.3% of cases. The median survival time was 15.4 months (95%CI: 13.9-16.1), and the 5-year, 10-year and 15-year overall survival rates were 19.5% (95%CI: 18.0%-21.1%), 7.7% (95%CI: 6.5%-8.8%) and 2.0% (95%CI: 0.8%-3.9%), respectively. Peasants with lung cancer had a lower median age at diagnosis, higher proportion residing in remote rural areas, and higher use of bituminous coal as a household fuel. They also have a lower proportion of early-stage cases, treatment at provincial or municipal hospitals, and surgical treatment, leading to poorer survival outcomes (HR=1.57). Even when considering factors such as gender, age, residential location, clinical stage at diagnosis, histological type, hospital level of service, and surgical intervention, peasants still exhibit a survival disadvantage. Multivariable Cox model analysis comparing peasants and non-peasants reveals that surgical intervention, tumor-node-metastasis (TNM) stage, and hospital level of service are common factors influencing survival prognosis, while the use of bituminous coal as a household fuel, hospital level of service and adenocarcinoma (compared to squamous cell carcinoma) are independent prognostic factors for lung cancer survival among peasants. CONCLUSIONS: The lower lung cancer survival rate among peasants is associated with their lower socioeconomic status, lower proportion of early-stage diagnoses, lower proportion of surgical interventions, and treatment at provincial-level hospitals. Furthermore, the impact of other factors such as high-risk exposure to bituminous coal pollution on survival prognosis requires further investigation.

Epidemiological characteristics of influenza in Mianyang, Sichuan, 2019-2021 / 中国热带医学

@#Objective To understand the epidemiological and etiological characteristics of influenza in Mianyang City from 2019 to 2021, so as to provide a basis for the prevention and control of influenza. Methods Influenza surveillance data in Mianyang City from 2019 to 2021 were collected and analyzed statistically. Results A total of 55 970 cases of influenza were reported in Mianyang City from 2019 to 2021, with an average annual incidence of 388.08/100 000. A total of 103 723 cases of influenza -like illness cases (ILI) were reported, with an average annual ILI% of 3.58%. The incidence, ILI% , and positive detection rates of influenza were all far higher than those in the corresponding period in 2019. The classification of the population is mainly composed of students under the age of 15. The top three reported cases were Fucheng District (20 118, 35.94%), Youxian District (6 394, 11.42%) and Jiangyou District (5 800, 10.36%). 10 126 samples of ILI were received and detected, with a positive rate of 19.53%, the positive rate of ILI samples was mainly students under 15 years old. The dominant strains of influenza viruses showed an alternating trend over the years, and A (H3) was the predominant type in 2019. Except for 2 A (H9) strains detected in 2021, the rest were all BV strains. Due to the impact of COVID-19 in 2020, the positive detection rate was low throughout the year. 43 outbreaks of ILI were reported, which were mainly occurred in winter, and most of them were in primary schools. Conclusion From 2019 to 2021, the characteristics of cases, ILI, pathogen surveillance and outbreak events of influenza in Mianyang City are basically the same, with students under 15 years of age and schools remaining the key population and sites of concern. the importance of non-pharmaceutical interventions for influenza prevention and control is further evidenced by the low incidence of influenza during the COVID-19 pandemic.

Differential activation mechanisms of lipid GPCRs by lysophosphatidic acid and sphingosine 1-phosphate.

Lysophospholipids are bioactive lipids and can signal through G-protein-coupled receptors (GPCRs). The best studied lysophospholipids are lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). The mechanisms of lysophospholipid recognition by an active GPCR, and the activations of lysophospholipid GPCR-G-protein complexes remain unclear. Here we report single-particle cryo-EM structures of human S1P receptor 1 (S1P1) and heterotrimeric Gi complexes formed with bound S1P or the multiple sclerosis (MS) treatment drug Siponimod, as well as human LPA receptor 1 (LPA1) and Gi complexes in the presence of LPA. Our structural and functional data provide insights into how LPA and S1P adopt different conformations to interact with their cognate GPCRs, the selectivity of the homologous lipid GPCRs for S1P versus LPA, and the different activation mechanisms of these GPCRs by LPA and S1P. Our studies also reveal specific optimization strategies to improve the MS-treating S1P1-targeting drugs.

[Survival in Lung Cancer among Female Never-smokers in Rural Xuanwei 
and Fuyuan Counties in Eastern Yunnan Province, China].

BACKGROUND: Lung cancer rates among women in rural Xuanwei and Fuyuan counties in eastern Yunnan province, China, are among the highest in the world, even though almost all women are non-smokers, and they tend to develop lung cancer at a younger age than other locations by roughly 5 yr-10 yr. This study investigated the survival of lung cancer patients among female never-smokers. METHODS: The female never-smokers, who had lived for many years in Xuanwei and Fuyuan counties, with lung cancer newly-diagnosed between July 2006 to March 2010, were followed up through the end of 2016. Age-standardized relative survival for all cases was calculated using local life table. The Kaplan-Meier method and Log-rank test were used to analyze the relationship between the variables and the prognosis in univariate analysis. Cox regression analysis was employed in the multivariate analysis. RESULTS: Among 1,250 total subjects, 1,075 died and the remaining 175 were censored during the follow-up, with a median follow-up period of 69 months (95%CI: 61.9-76.0). Overall, the mean age was (54.8 ±10.9) yr, with variable clinical stages: 3.5% of cases were stage I, 8.7% stage II, 20.7% stage III, 29.7% stage IV, and 37.4% stage unknown. The 645 patients(51.6%) with cyto-histological diagnosis contains 303 with Squamous cell carcinoma, and 231 with adenocarcinoma, 24 with small cell, 43 with other specified type and 39 with unknown histological type. Only 215 (17.2%) patients received surgery, 487 (39.0%) were treated without surgery, and 548 (43.8%) did not receive any specific anticancer therapy. The 5-year observed survival rate and age-standardized relative survival were 8.9% (95%CI: 7.0-10.6), and 10.1% (95%CI: 3.7-20.5) respectively, with a median survival of 13.2 months. The 5-year survival rates were 41.1% for stage I, 22.4% for stage II, 5.3% for stage III, 1.3% for stage IV, 11.2% for missing stage, 17.9% for adenocarcinoma, and 5.6% for squamous cell carcinoma respectively. Surgery significantly improved 5-year survival rate compared with non-surgery (34.8% vs 3.2%, P<0.001). The patients with non-treatment, aged 65 years and older, living in rural areas and farmer with low socioeconomic status had poorer survival, whereas the patients treated in provincial hospitals and chest X-ray screening had better survival. Cox multivariate analysis further showed that stage of tumor-node-metastasis (TNM), treatment status, hospital-level, and X-ray screening were factors correlated with survival. CONCLUSIONS: Patients with lung cancer among female never-smokers in Xuanwei and Fuyuan experience poorer survival, because they are less likely to be diagnosed at early stage, as well as less likely to receive surgery and comprehensive treatment. Furthermore low socioeconomic status and poor health security are also responsible for the low survival.

Spinal Fusion in Parkinson's Disease Patients: A Propensity Score-Matched Analysis With Minimum 2-Year Surveillance.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To compare outcomes and complication rates between patients with and without Parkinson's disease (PD) patients undergoing surgery for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: There is limited literature evaluating the impact of PD on long-term outcomes after thoracolumbar fusion surgery for ASD. METHODS: Patients admitted from 2009 to 2011 with diagnoses of ASD who underwent any thoracolumbar fusion procedure with a minimum 2-year follow-up surveillance were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System. A 1:1 propensity score-match by age, Deyo score, and number of fused vertebral levels was conducted before comparing surgical outcomes of patients with ASD with and without PD. Univariate analysis compared demographics, complications, and subsequent revision. Multivariate binary stepwise logistic regression models identified independent predictors of these outcomes (covariates: age, sex, Deyo Index score, and PD diagnosis). RESULTS: A total of 576 propensity score-matched patients were identified (PD: n = 288; no-PD: n = 288), with a mean age of 69.7 years (PD) and 70.2 years (no-PD). Each cohort had comparable distributions of age, sex, race, insurance provider, Deyo score, and number of levels fused (all P > 0.05). Patients with PD incurred higher total charges across ASD surgery-related visits ($187,807 vs. $126,610, P < 0.001), yet rates of medical complications (35.8% PD vs. 34.0% no-PD, P = 0.662) and revision surgery (12.2% vs. 10.8%, P > 0.05) were comparable. Postoperative mortality rates were comparable between PD and no-PD cohorts (2.8% vs. 1.4%, P = 0.243). Logistic regression identified nine-level or higher spinal fusion as a significant predictor for an increase in total complications (odds ratio = 5.64); PD was not associated with increased odds of any adverse outcomes. CONCLUSION: Aside from higher hospital charges incurred, patients with PD experienced comparable overall complication and revision rates to a propensity score-matched patient cohort without PD from the general population undergoing thoracolumbar fusion surgery. These results can support management of concerns and postoperative expectations in this patient cohort. LEVEL OF EVIDENCE: 3.

MicroED structure of the NaK ion channel reveals a Na+ partition process into the selectivity filter.

Sodium (Na+) is a ubiquitous and important inorganic salt mediating many critical biological processes such as neuronal excitation, signaling, and facilitation of various transporters. The hydration states of Na+ are proposed to play critical roles in determining the conductance and the selectivity of Na+ channels, yet they are rarely captured by conventional structural biology means. Here we use the emerging cryo-electron microscopy (cryoEM) method micro-electron diffraction (MicroED) to study the structure of a prototypical tetrameric Na+-conducting channel, NaK, to 2.5 Å resolution from nano-crystals. Two new conformations at the external site of NaK are identified, allowing us to visualize a partially hydrated Na+ ion at the entrance of the channel pore. A process of dilation coupled with Na+ movement is identified leading to valuable insights into the mechanism of ion conduction and gating. This study lays the ground work for future studies using MicroED in membrane protein biophysics.

The Impact of Comorbid Mental Health Disorders on Complications Following Cervical Spine Surgery With Minimum 2-Year Surveillance.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To improve understanding of the impact of comorbid mental health disorders (MHDs) on long-term outcomes following cervical spinal fusion in cervical radiculopathy (CR) or cervical myelopathy (CM) patients. SUMMARY OF BACKGROUND DATA: Subsets of patients with CR and CM have MHDs, and their impact on surgical complications is poorly understood. METHODS: Patients admitted from 2009 to 2013 with CR or CM diagnoses who underwent cervical surgery with minimum 2-year surveillance were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System. Patients with a comorbid MHD were compared against those without (no-MHD). Univariate analysis compared demographics, complications, readmissions, and revisions between MHD and no-MHD cohorts. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: age, sex, Charlson/Deyo score, and surgical approach). RESULTS: A total of 20,342 patients (MHD: n = 4819; no-MHD: n = 15,523) were included. MHDs identified: depressive (57.8%), anxiety (28.1%), sleep (25.2%), and stress (2.9%). CR patients had greater prevalence of comorbid MHD than CM patients (P = 0.015). Two years postoperatively, all patients with MHD had significantly higher rates of complications (specifically: device-related, infection), readmission for any indication, and revision surgery (all P < 0.05); regression modeling corroborated these findings and revealed combined surgical approach as the strongest predictor for any complication (CR, odds ratio [OR]: 3.945, P < 0.001; CM, OR: 2.828, P < 0.001) and MHD as the strongest predictor for future revision (CR, OR: 1.269, P = 0.001; CM, OR: 1.248, P = 0.008) in both CR and CM cohorts. CONCLUSION: Nearly 25% of patients admitted for CR and CM carried comorbid MHD and experienced greater rates of any complication, readmission, or revision, at minimum, 2 years after cervical spine surgery. Results must be confirmed with retrospective studies utilizing larger national databases and with prospective cohort studies. Patient counseling and psychological screening/support are recommended to complement surgical treatment. LEVEL OF EVIDENCE: 3.

Complications in Patients Undergoing Spinal Fusion After THA.

INTRODUCTION: Patients with lumbar spine and hip disorders may, during the course of their treatment, undergo spinal fusion and THA. There is disagreement among prior studies regarding whether patients who undergo THA and spinal fusion are at increased risk of THA dislocation and other hip-related complications. QUESTIONS / PURPOSES: Is short or long spinal fusion associated with an increased rate of postoperative complications in patients who underwent a prior THA? PATIENTS AND METHODS: A retrospective study of New York State's Department of Health database (SPARCS) was performed. SPARCS has a unique identification code for each patient, allowing investigators to track the patient across multiple admissions. The SPARCS dataset spans visit data of patients of all ages and races across urban and rural locations. The SPARCs dataset encompasses all facilities covered under New York State Article 28 and uses measures to further representative reporting of data concerning all races. Owing to the nature of the SPARCS dataset, we are unable to comment on data leakage, as there is no way to discern between a patient who does not subsequently seek care and a patient who seeks care outside New York State. ICD-9-Clinical Modification codes identified adult patients who underwent elective THA from 2009 to 2011. Patients who had subsequent spinal fusion (short: 2-3 levels, or long: ≥ 4 levels) with a diagnosis of adult idiopathic scoliosis or degenerative disc disease were identified. Forty-nine thousand nine hundred twenty patients met the inclusion criteria of the study. In our inclusion and exclusion criteria, there was no variation with respect to the distribution of sex and race across the three groups of interest. Patients who underwent a spinal procedure (short versus long fusion) had comparable age. However, patients who did not undergo a spinal procedure were older than patients who had short fusion (65 ± 12.4 years versus 63 ± 10.7 years; p < 0.001). Multivariate binary logistic regression models that controlled for age, sex, and Deyo/Charlson scores were used to investigate the association between spinal fusion and THA revisions, postoperative dislocation, contralateral THAs, and total surgical complications to the end of 2013. A total of 49,920 patients who had THAs were included in one of three groups (no subsequent spinal fusion: n = 49,209; short fusion: n = 478; long fusion: n = 233). RESULTS: Regression models revealed that short and long spinal fusions were associated with increased odds for hip dislocation, with associated odds ratios (ORs) of 2.2 (95% CI, 1.4-3.6; p = 0.002), and 4.4 (95% CI, 2.7-7.3; p < 0.001), respectively. Patients who underwent THA and spinal surgery also had an increased odds for THA revision, with ORs of 2.0 (95% CI, 1.4-2.8; p < 0.001) and 3.2 (95% CI, 2.1-4.8; p < 0.001) for short and long fusion, respectively. However, spinal fusions were not associated with contralateral THAs. Further, short and long spinal fusions were associated with increased surgical complication rates (OR = 2.8, 95% CI, 2.1-3.8, p < 0.001; OR = 5.3, 95% CI, 3.8-7.4, p < 0.001, respectively). CONCLUSION: We showed that spinal fusion in adults is associated with an increased frequency of complications and revisions in patients who have had a prior THA. Specifically, patients who had a long spinal fusion after THA had 340% higher odds of experiencing a hip dislocation and 220% higher odds of having to undergo a revision THA. Further research is necessary to determine whether this relationship is associated with the surgical order, or whether more patient-specific surgical goals of revision THA should be developed for patients with a spinal deformity. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Impact of Comorbid Mental Health Disorders on Complications Following Adult Spinal Deformity Surgery With Minimum 2-Year Surveillance.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: To compare long-term outcomes between patients with and without mental health comorbidities who are undergoing surgery for adult spinal deformity (ASD). SUMMARY OF BACKGROUND DATA: Recent literature reveals that one in three patients admitted for surgical treatment for ASD has comorbid mental health disorder. Currently, impacts of baseline mental health status on long-term outcomes following ASD surgery have not been thoroughly investigated. METHODS: Patients admitted from 2009 to 2013 with diagnoses of ASD who underwent more than or equal to 4-level thoracolumbar fusion with minimum 2-year follow-up were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System (SPARCS). Patients were stratified by fusion length (short: 4-8-level; long: ≥9 level). Patients with comorbid mental health disorder (MHD) at time of admission were selected for analysis (MHD) and compared against those without MHD (no-MHD). Univariate analysis compared demographics, complications, readmissions, and revisions between cohorts for each fusion length. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: fusion length, age, female sex, and Deyo score). RESULTS: Six thousand twenty patients (MHD: n = 1631; no-MHD: n = 4389) met inclusion criteria. Mental health diagnoses included disorders of depression (59.0%), sleep (28.0%), anxiety (24.0%), and stress (2.3%). At 2-year follow-up, MHD patients with short fusion had significantly higher complication rates (P = 0.001). MHD patients with short or long fusion also had significantly higher rates of any readmission and revision (all P ≤ 0.002). Regression modeling revealed that comorbid MHD was a significant predictor of any complication (odds ratio [OR]: 1.17, P = 0.01) and readmission (OR: 1.32, P < 0.001). MHD was the strongest predictor of any revision (OR: 1.56, P < 0.001). Long fusion most strongly predicted any complication (OR: 1.87, P < 0.001). CONCLUSION: ASD patients with comorbid depressive, sleep, anxiety, and stress disorders were more likely to experience surgical complications and revision at minimum of 2 years following spinal fusion surgery. Proper patient counseling and psychological screening/support is recommended to complement ASD treatment. LEVEL OF EVIDENCE: 3.

Complication Rates and Maintenance of Correction After 3-Column Osteotomy in the Elderly: Report of 55 Patients With 2-Year Follow-up.

BACKGROUND: Three-column osteotomies (3CO) provide substantial correction for adult spinal deformity (ASD), but carry risks of complications and revisions. The risk-benefit balance of 3CO in the elderly remains unclear. OBJECTIVE: To evaluate sagittal alignment and complications after 3CO in a population over 70-yr old. METHODS: Radiographic retrospective review of consecutive patients over 70 yr ("Elderly") undergoing 3CO for ASD. Demographic, operative, and outcomes data were collected. Full-spine radiographs were analyzed at baseline and 2-yr postoperatively. Results were compared to a group of young controls ("Young") matched by global sagittal alignment. RESULTS: Elderly (n = 55) and Young (n = 52) were similar in operating room time, blood loss, levels fused, and revision surgeries. Elderly and Young groups had similar baseline radiographic malalignment for pelvic tilt, pelvic incidence-lumbar lordosis (PI-LL), and sagittal vertical axis (P > .5 for all). At 2-yr postoperatively, both groups underwent significant improvement in the setting of sagittal alignment parameters (Elderly: sagittal vertical axis 150 mm to 59 mm, P < .001; pelvic tilt 33° to 25°, P < .001; PI-LL 35° to PI-LL 6°, P < .001). However, the Elderly group underwent significantly greater correction in PI-LL than the Young group (-29° vs -20°, P = .024). There were no differences in total, intraoperative or postoperative complications or revisions between groups, though the Elderly group had more intraoperative complications when major blood loss was included. The Elderly group had more severe proximal junctional kyphosis (22.1° vs 9.6° in Young; P < .001). CONCLUSION: Compared to young patients, elderly patients may achieve the same, or even better, correction in radiographic spinopelvic parameters. In addition, not only the total intraoperative and postoperative complication rates but also revision rates were comparable between both groups.

Ion Binding to Transport Proteins using Isothermal Titration Calorimetry.

Isothermal titration calorimetry (ITC) is an emerging, label-free technology used to measure ligand binding to membrane proteins. This technology utilizes a titration calorimeter to measure the heat exchange upon ligands binding to proteins, the magnitude of which is based on the overall enthalpy of the reaction. In this protocol, the steps we and others use to measure ion binding to ion transport proteins are described.

A study on the temperature field of a bronze-bonded diamond wheel dressed using a laser/ultrasonic vibration combined method.

To solve problems in dressings for metal-bonded super-hard abrasive wheels, such as low efficiency and rapid wear, this article introduces a laser-assisted ultrasonic vibration dressing technique. Firstly, finite-element simulations were conducted on the dressing process of a bronze-bonded diamond wheel, and the wheel's temperature field distributions under different laser parameters were simulated. By analysing the simulation results of temperature fields and the melting point of the bronze bond, the laser parameters for laser-assisted ultrasonic vibration dressing tests were optimized, and then actual tests were carried out on the bronze-bonded diamond wheel. Results showed that, with appropriate technology parameters, the laser-assisted ultrasonic vibration dressing technique achieved desirable dressing results; specifically, the dressing force was low, the abrasive particles had high protrusions and the wheel had a large chip space and favourable surface topography.

Atomic resolution structure determination by the cryo-EM method MicroED.

The electron cryo-microscopy (cryoEM) method MicroED has been rapidly developing. In this review we highlight some of the key steps in MicroED from crystal analysis to structure determination. We compare and contrast MicroED and the latest X-ray based diffraction method the X-ray free-electron laser (XFEL). Strengths and shortcomings of both MicroED and XFEL are discussed. Finally, all current MicroED structures are tabulated with a view to the future.

Global sagittal axis: a step toward full-body assessment of sagittal plane deformity in the human body.

OBJECTIVE Sagittal malalignment requires higher energy expenditure to maintain an erect posture. Because the clinical impact of sagittal alignment is affected by both the severity of the deformity and recruitment of compensatory mechanisms, it is important to investigate new parameters that reflect both disability level and compensatory mechanisms for all patients. This study investigated the clinical relevance of the global sagittal axis (GSA), a novel measure to evaluate the standing axis of the human body. METHODS This is a retrospective review of patients who underwent full-body radiographs and completed health-related quality of life (HRQOL) questionnaires: Oswestry Disability Index (ODI), Scoliosis Research Society-22, EuroQol-5D (EQ-5D), and the visual analog scale for back and leg pain. The GSA was defined as the angle formed by a line from the midpoint of the femoral condyles to the center of C-7, and a line from the midpoint between the femoral condyles to the posterior superior corner of the S-1 sacral endplate. After evaluating the correlation of GSA/HRQOL with sagittal parameters, linear regression models were generated to investigate how ODI and GSA related to radiographic parameters (T-1 pelvic angle, pelvic retroversion, knee flexion, and pelvic posterior translation). RESULTS One hundred forty-three patients (mean age 44 years) were included. The GSA correlated significantly with all HRQOL (up to r = 0.6 with EQ-5D) and radiographic parameters (up to r = 0.962 with sagittal vertical axis). Regression between ODI and sagittal radiographic parameters identified the GSA as an independent predictor (r = 0.517, r2 = 0.267; p < 0.001). Analysis of standardized coefficients revealed that when controlling for deformity, the GSA increased with a concurrent decrease in pelvic retroversion (-0.837) and increases in knee flexion (+0.287) and pelvic posterior translation (+0.193). CONCLUSIONS The GSA is a simple, novel measure to assess the standing axis of the human body in the sagittal plane. The GSA correlated highly with spinopelvic and lower-extremities sagittal parameters and exhibited remarkable correlations with HRQOL, which exceeded other commonly used parameters.

Ratio of lumbar 3-column osteotomy closure: patient-specific deformity characteristics and level of resection impact correction of truncal versus pelvic compensation.

PURPOSE: The resection point of a lumbar three-column osteotomy (3CO) creates separation of the spino-pelvic complex. This study investigates the impact of patients' baseline deformity and level of 3CO resection on the distribution of correction between the trunk and the pelvis following osteotomy closure. METHODS: Patients who underwent single lumbar 3CO, upper instrumented vertebra (UIV) T1-T10, and 6 month follow-up were included. The truncal and pelvic closures were calculated based on the vertebrae adjacent to the osteotomy level and the impact of radiographic parameters and level of 3CO on the closures were analyzed. RESULTS: 113 patients were included. Patients who experienced more pelvic correction had significantly higher Pelvic Tilt and lower Sagittal Vertical Axis at baseline. Patients who underwent more caudal osteotomies with higher pelvic compensation with modest SVA sustained more pelvic correction. CONCLUSIONS: The osteotomy closure is driven by patient's specific deformity. More caudal osteotomy level leads to greater pelvic tilt improvement. LEVEL OF EVIDENCE: III.

The benefit of nonoperative treatment for adult spinal deformity: identifying predictors for reaching a minimal clinically important difference.

BACKGROUND CONTEXT: Adult spinal deformity (ASD) patients may gain minimal clinically important difference (MCID) in one or more of the health-related quality-of-life instruments without surgical intervention. The present study identifies the baseline characteristics of this subset of nonoperative patients and proposes predictors of those most likely to benefit. PURPOSE: The study aims to determine the factors that affect likelihood of nonoperative patients to reach MCID. STUDY DESIGN/SETTING: This is a retrospective review of a prospective, multicenter database. PATIENT SAMPLE: The study includes nonoperative ASD patients. OUTCOME MEASURES: Health-related quality-of-life measures, including the Scoliosis Research Society (SRS)-22 questionnaire, were used. METHODS: The study used a multicenter database of 215 nonoperative patients with ASD and with minimum 2-year follow-up. Using a multivariate analysis, two groups were compared to identify possible predictors: those who reached MCID in the SRS pain or activity (N=86) at 2 years and those who did not reach MCID (N=129). A subgroup multivariate analysis of patients with a deficit (potential improvement) in both SRS pain and activity (N=84) was performed. Data collection was supported by a grant from DePuy for the International Spine Study Group Foundation. RESULTS: At baseline, the nonoperative patients who reached MCID had a significantly lower SRS pain score (3.0 vs. 3.6), smaller thoracolumbar Cobb (TL Cobb) angle (29.6° vs. 36.5°; 87 patients with SRS-Schwab classification of lumbar or double), lower sacral slope (33.1° vs. 36.4°), and less lumbar lordosis (46.5° vs. 52.8°) (all p<.05). The SRS pain and TL Cobb were significant predictors for reaching MCID. The pelvic incidence minus lumbar lordosis (PI-LL) was significant on univariate analysis but not on multivariate analysis (7.5° vs. 2.6°; p=.14). In the subset of severely disabled patients, worse vertebral obliquity was a predictor for not achieving MCID (p<.05). CONCLUSIONS: Nonoperative ASD patients who achieved MCID in SRS activity or pain had a lower baseline SRS pain score and less coronal deformity in the TL region. Greater baseline pain offers significant room for potential improvement, which may be important in identifying ASD patients who have the potential to reach MCID nonoperatively. Coronal deformities in the TL region and associated vertebral obliquity may negatively impact potential for improvement in nonoperative care.

Role of pelvic translation and lower-extremity compensation to maintain gravity line position in spinal deformity.

OBJECT: Previous forceplate studies analyzing the impact of sagittal-plane spinal deformity on pelvic parameters have demonstrated the compensatory mechanisms of pelvis translation in addition to rotation. However, the mechanisms recruited for this pelvic rotation were not assessed. This study aims to analyze the relationship between spinopelvic and lower-extremity parameters and clarify the role of pelvic translation. METHODS: This is a retrospective study of patients with spinal deformity and full-body EOS images. Patients with only stenosis or low-back pain were excluded. Patients were grouped according to T-1 spinopelvic inclination (T1SPi): sagittal forward (forward, > 0.5°), neutral (-6.3° to 0.5°), or backward (< -6.3°). Pelvic translation was quantified by pelvic shift (sagittal offset between the posterosuperior corner of the sacrum and anterior cortex of the distal tibia), hip extension was measured using the sacrofemoral angle (SFA; the angle formed by the middle of the sacral endplate and the bicoxofemoral axis and the line between the bicoxofemoral axis and the femoral axis), and chin-brow vertical angle (CBVA). Univariate and multivariate analyses were used to compare the parameters and correlation with the Oswestry Disability Index (ODI). RESULTS: In total, 336 patients (71% female; mean age 57 years; mean body mass index 27 kg/m(2)) had mean T1SPi values of -8.8°, -3.5°, and 5.9° in the backward, neutral, and forward groups, respectively. There were significant differences in the lower-extremity and spinopelvic parameters between T1SPi groups. The backward group had a normal lumbar lordosis (LL), negative SVA and pelvic shift, and the largest hip extension. Forward patients had a small LL and an increased SVA, with a large pelvic shift creating compensatory knee flexion. Significant correlations existed between lower-limb parameter and pelvic shift, pelvic tilt, T-1 pelvic angle, T1SPi, and sagittal vertical axis (0.3 < r < 0.8; p < 0.001). ODI was significantly correlated with knee flexion and pelvic shift. CONCLUSIONS: This is the first study to describe full-body alignment in a large population of patients with spinal pathologies. Furthermore, patients categorized based on T1SPi were found to have significant differences in the pelvic shift and lower-limb compensatory mechanisms. Correlations between lower-limb angles, pelvic shift, and ODI were identified. These differences in compensatory mechanisms should be considered when evaluating and planning surgical intervention for adult patients with spinal deformity.

Natural Head Posture in the Setting of Sagittal Spinal Deformity: Validation of Chin-Brow Vertical Angle, Slope of Line of Sight, and McGregor's Slope With Health-Related Quality of Life.

BACKGROUND: The maintenance of horizontal gaze is an essential function of upright posture and global sagittal spinal alignment. Horizontal gaze is classically measured by the chin-brow vertical angle (CBVA), which is not readily measured on most lateral spine radiographs. OBJECTIVE: To evaluate relations between CBVA and the slope of the line of sight, the slope of McGregor's line (McGS), and Oswestry Disability Index. METHODS: Patients were identified from a single center database of 531 spine patients who underwent full-body EOS x-rays. Correlations between CBVA, the slope of the line of sight, and McGS were assessed. Using a quadratic regression with Oswestry Disability Index and CBVA, windows of low disability were identified. Comparison of sagittal spinopelvic parameters was carried out between patients with "ascending gaze" and "neutral position." RESULTS: Three hundred three patients were included (74% female, mean age 54.8 years, body mass index 26.6 ± 6.0 kg/m). CBVA strongly correlated with the slope of the line of sight (r = 0.996) and McGS (r = 0.862). Regression studies between Oswestry Disability Index and CBVA yielded a range of values corresponding to low disability (-4.7 degrees to 17.7 degrees). Similarly, a low disability range for the slope of the line of sight (-5.1 degrees to 18.5 degrees) and McGS (-5.7 degrees to 14.3 degrees) was computed. Patients with "ascending gaze" had a worse spinopelvic alignment than "neutral position" patients. CONCLUSION: The slope of the line of sight and McGS correlated strongly with CBVA and can be used as surrogate measures. The range of values for these measures corresponding to low disability was identified. These values can be used as a general guideline to assess alignment for diagnostic purposes. Cervical compensatory mechanism may modify the natural head position in sagittally misaligned patients. ABBREVIATIONS: CBVA, chin-brow vertical angleHRQoL, health-related quality of lifeMcGS, slope of McGregor's lineODI, Oswestry Disability IndexSLs, slope of the line of sight.