Assembly Structure Formation in Bulk and Ultrathin Films of Poly(substituted methylene) Having an Azobenzene Side Chain.

The density of the side chain introduced to a polymer main chain greatly influences the properties and functions of the polymer. This work first reports on the packing structure and properties at an interface of a poly(substituted methylene) where an azobenzene side chain is introduced at every carbon atom in the main chain (C1PAz). The structure and properties are compared with those of a conventional vinyl polymer [poly(methacrylate)] possessing an identical side-chain structure (C2PAz). The packing structure in the bulk state analyzed by X-ray measurements revealed that C1PAz adopts a highly ordered rectangular unit cell structure, whereas C2PAz shows a less ordered lamellar one. Langmuir film balance experiments indicated that both polymers with the trans-azobenzene give essentially the identical 2D side-chain occupying area on water, which agrees well with the smectic B (hexatic packing) model based on the X-ray data. Upon transfer onto a solid substrate, only C1PAz shows a conformational transformation to a spread bilayer-type layer, most probably due to conformational frustration stemming from the crowding of the side chains. This study proposes new insights into the effects of side-chain density on the self-assembly and photoreaction of azobenzene-containing polymers, which are expected to expand the possibilities of polymer design for various applications.

Effect of anti-claudin 18.2 monoclonal antibody zolbetuximab alone or combined with chemotherapy or programmed cell death-1 blockade in syngeneic and xenograft gastric cancer models.

The development of targeted cancer therapies based on monoclonal antibodies against tumor-associated antigens has progressed markedly over recent decades. This approach is dependent on the identification of tumor-specific, normal tissue-sparing antigenic targets. The transmembrane protein claudin-18 splice variant 2 (CLDN18.2) is frequently and preferentially displayed on the surface of primary gastric adenocarcinomas, making it a promising monoclonal antibody target. Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. In studies using xenograft or syngeneic models with gastric cancer cell lines, zolbetuximab mediated death of CLDN18.2-positive human cancer cell lines via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity in vitro and demonstrated anti-tumor efficacy as monotherapy and combined with chemotherapy in vivo. Mice treated with zolbetuximab plus chemotherapy displayed a significantly higher frequency of tumor-infiltrating CD8+ T cells versus vehicle/isotype control-treated mice. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.

Neurological recovery rate and predictive factors of incomplete AIS grade C spinal cord injury in the older aged population.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To define the prognosis and predictive factors for neurological improvement in older patients with incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale grade C (AIS-C). SETTINGS: Multi-institutions in Japan. METHODS: We included patients aged ≥65 years with traumatic SCI of AIS-C who were treated conservatively or surgically with >3 follow-up months. To identify factors related to neurological improvement, patients were divided into three groups according to their neurological status at the final follow-up, with univariate among-group comparisons of demographics, radiographic, and therapeutic factors. Significant variables were included in the multivariate logistic regression analysis. RESULTS: Overall, 296 older patients with SCI of AIS-C on admission were identified (average age: 75.2 years, average follow-up: 18.7 months). Among them, 190 (64.2%) patients improved to AIS-D and 21 (7.1%) patients improved to AIS-E at final follow-up. There were significant among-group differences in age (p = 0.026), body mass index (p = 0.007), status of pre-traumatic activities of daily living (ADL) (p = 0.037), and serum albumin concentrations (p = 0.011). Logistic regression analysis showed no significant differences in variables in the stratified group of patients who improved to AIS-D. Meanwhile, serum albumin was a significant variable in patients who improved to AIS-E (p = 0.026; OR: 6.20, pre-traumatic ADL was omitted due to data skewness). CONCLUSIONS: Most older patients with incomplete AIS-C SCI demonstrated at least 1 grade of neurological improvement. However, <10% of patients achieved complete recovery. Key predictors of complete recovery were high serum albumin levels on admission and independent pre-traumatic ADL. SPONSORSHIP: No funding was received for this study.

Comparison of Skeletal Stability after Le Fort I Osteotomy With Bone Fixation Using Biodegradable and Titanium Systems: A Retrospective Study.

The titanium osteosynthesis system used for fixing bone segments after maxillary osteotomy provides reliable outcomes owing to its biocompatibility and adequate strength. In addition, several studies have evaluated the skeletal stability after maxillary osteotomy with fixation using a biodegradable system. However, the indications for applying a biodegradable system after maxillary osteotomy remain controversial. Therefore, this study aimed to compare the long-term skeletal stability of bone segments after maxillary osteotomy with bone fixation using biodegradable and titanium osteosynthesis systems and to assess the usefulness of a biodegradable osteosynthesis system. Patients who underwent Le Fort I osteotomy of the maxilla to correct jaw deformities between April 2008 and March 2021 were included in this study. A total of 45 patients were included, with 28 in the biodegradable osteosynthesis system group and 17 in the titanium group. Cephalometric and computed tomography analyses were performed to evaluate the skeletal stability of the bone segments after maxillary osteotomy with bone fixation using biodegradable or titanium osteosynthesis systems. The maxillary segment was repositioned anteriorly with a clockwise rotation. Skeletal stability was similar between the biodegradable and titanium osteosynthesis systems. Segmental changes occurred mainly in the first 6 months after surgery, and the segment was completely stable between 6 and 12 months after surgery. This study revealed no significant differences in skeletal stability after maxillary osteotomy between the biodegradable and titanium osteosynthesis systems. However, the findings in this study should be interpreted with caution owing to the small sample size and small amount of maxillary-segment movement.

Long-term effects of diffuse idiopathic skeletal hyperostosis on physical function: A longitudinal analysis.

BACKGROUND: Cross-sectional studies on diffuse idiopathic skeletal hyperostosis have focused on its incidence and related factors. However, the long-term changes caused by the disease remain unclear. This longitudinal cohort study aimed to elucidate the progression of diffuse idiopathic skeletal hyperostosis and its effects on physical function, health-related quality of life, and spinal alignment. METHODS: We recruited 255 older adults (87 men and 168 women; average age, 71.3 years in 2014) who attended local health checkups in 2014 and 2020. Height, body weight, body mass index, blood pressure, grip strength, functional reach, and bone mineral density were measured. The prevalence, location, number of ossified contiguous vertebrae, and spinopelvic parameters were estimated using whole-spine standing radiographs. For health-related quality of life assessment, the Oswestry disability index and EuroQuol-5D were obtained. We performed a 1:1 case-control study with age and sex-matched patients with and without diffuse idiopathic skeletal hyperostosis and analyzed progression over a 6-year period. RESULTS: In 2014, 39 (15.3%) of 255 patients were diagnosed with diffuse idiopathic skeletal hyperostosis (24 males and 15 females), which occurred more frequently in the elderly and males. In 2020, 12 (4.3%) patients were newly diagnosed with diffuse idiopathic skeletal hyperostosis, and 28 (71.7%) of 39 patients diagnosed in 2014 showed varying degrees of progression. Compared with age- and sex-matched patients without diffuse idiopathic skeletal hyperostosis, patients with the condition had higher body mass index and lumbar bone mineral density, larger sagittal vertical axis, and greater T1-pelvic angle. Changes in physical function and spinal-pelvic parameters during the 6-year period did not differ between the groups. CONCLUSIONS: Over a 6-year period, the prevalence of diffuse idiopathic skeletal hyperostosis increased by 4.3%, and it progressed in 71.7% of patients. However, it had little effect on longitudinal physical function, health-related quality of life, and spinopelvic parameters in older adults.

Impact of multi-rod reinforcement on rod fractures in adult spinal deformity: A retrospective case series with a minimum follow up of 5 years.

BACKGROUND: This study aimed to determine the impact of the multi-rod construct on rod fractures over a minimum follow-up period of five years in comparison to that with the conventional two-rod construct using the same technique, rod composition, and rod reinforcement method. METHODS: Data were retrospectively retrieved from a prospectively collected, single-center database. Consecutive patients >50 years of age who underwent thoracopelvic corrective fusion with planned two-stage anterior-posterior surgery and were followed up for at least five years were included in this study. The incidence of rod fracture in the conventional two-rod and multi-rod groups was investigated. RESULTS: A total of 58 patients (mean age, 68.9 years) were included in this study (follow-up rate, 73.4 %). Rod fracture was identified in 25 patients (43.1 %), within an average period of 25.1 months. The incidence of rod fracture in the multi-rod group was significantly lower than that in the two-rod group. However, there was no significant difference in the time to rod fracture between the two groups. Reinforcement of the multi-rod to the distal portion of the connector of the iliac screw had the lowest fracture rate and no cases of reoperation. CONCLUSIONS: The incidence of rod fracture was significantly lower using multi-rod reinforcement, but the timing of rod fracture did not differ, compared to that with the two-rod construct using the same surgical technique and rod material. Multi-rod reinforcement covering the distal portion of the iliac screw is recommended to reduce the risk of fracture and reoperation.

Influence of the timing of surgery for cervical spinal cord injury without bone injury in the elderly: A retrospective multicenter study.

BACKGROUND: Although previous studies have demonstrated the advantages of early surgery for traumatic spinal cord injury (SCI), the appropriate surgical timing for cervical SCIs (CSCIs) without bone injury remains controversial. Here, we investigated the influence of relatively early surgery within 48 h of injury on the neurological recovery of elderly patients with CSCI and no bone injury. METHODS: In this retrospective multicenter study, we reviewed data from 159 consecutive patients aged ≥65 years with CSCI without bone injury who underwent surgery in participating centers between 2010 and 2020. Patients were followed up for at least 6 months following CSCI. We divided patients into relatively early (≤48 h after CSCI, n = 24) and late surgery (>48 h after CSCI, n = 135) groups, and baseline characteristics and neurological outcomes were compared between them. Multivariate analysis was performed to identify factors associated with neurological recovery. RESULTS: The relatively early surgery group demonstrated a lower prevalence of cardiac disease, poorer baseline American Spinal Injury Association (ASIA) impairment scale grade, and lower baseline ASIA motor score (AMS) than those of the late surgery group (P < 0.030, P < 0.001, and P < 0.001, respectively). Although the AMS was lower in the relatively early surgery group at 6 months following injury (P = 0.001), greater improvement in this score from baseline to 6-months post injury was observed (P = 0.010). Multiple linear regression analysis revealed that relatively early surgery did not affect postoperative improvement in AMS, rather, lower baseline AMS was associated with better AMS improvement (P < 0.001). Delirium (P = 0.006), pneumonia (P = 0.030), and diabetes mellitus (P = 0.039) negatively influenced postoperative improvement. CONCLUSIONS: Although further validation by future studies is required, relatively early surgery did not show a positive influence on neurological recovery after CSCI without bone injury in the elderly.

Deterioration of apatite orientation in the cholecystokinin B receptor gene (Cckbr)-deficient mouse femurs.

INTRODUCTION: The discrepancy between bone mineral density (BMD), the gold standard for bone assessment, and bone strength is a constraint in diagnosing bone function and determining treatment strategies for several bone diseases. Gastric hypochlorhydria induced by clinically used proton pump inhibitor (PPI) therapy indicates a discordance between changes in BMD and bone strength. Here, we used Cckbr-deficient mice with gastric hypochlorhydria to examine the effect of gastric hypochlorhydria on bone mass, BMD, and preferential orientation of the apatite crystallites, which is a strong indicator of bone strength. MATERIALS AND METHODS: Cckbr-deficient mice were created, and their femurs were analyzed for BMD and preferential orientation of the apatite c-axis along the femoral long axis. RESULTS: Cckbr-deficient mouse femurs displayed a slight osteoporotic bone loss at 18 weeks of age; however, BMD was comparable to that of wild-type mice. In contrast, apatite orientation in the femur mid-shaft significantly decreased from 9 to 18 weeks. To the best of our knowledge, this is the first report demonstrating the deterioration of apatite orientation in the bones of Cckbr-deficient mice. CONCLUSION: Lesions in Cckbr-deficient mice occurred earlier in apatite orientation than in bone mass. Hence, bone apatite orientation may be a promising method for detecting hypochlorhydria-induced osteoporosis caused by PPI treatment and warrants urgent clinical applications.

The relationship between frailty and spinal alignment in the elderly general population: a two-year longitudinal study.

PURPOSE: Frailty is caused by age-related decline in physical function, which may contribute to worsening spinal alignment. Cardiovascular Health Study (CHS)-criteria for assessing physical function seem more appropriate than frailty index which evaluate comorbiduty. However, there have been no reports investigating the relationship between frailty and spinal alignment using the CHS criteria. This study aimed to examine spinal radiographic parameters using the CHS criteria in volunteers participating in a health screening study. METHODS: The subjects were 211 volunteers (71 males and 140 females) aged 60-89 years old who participated in the TOEI study in 2018 and 2020. They were divided into three groups (R: robust, PF: pre-frailty, and F: frailty) according to the score of the Japanese version of the CHS (J-CHS) criteria in 2018. The radiographic parameters were evaluated using a whole-spine standing X-ray. RESULTS: There were 67 volunteers in group R, 124 volunteers in group PF, and 20 volunteers in group F. Of the five items in the J-CHS criteria, low activity was the most common in the PF group (64%). Low activity was also the most common in the F group (100%). Regarding spinal alignment, significant differences were found in C7SVA in 2020 (R:PF:F = 26:31:62 mm, P = 0.047), C2SVA in 2018 (20:34:63 mm, P = 0.019), and C2SVA in 2020 (37:47:78 mm, P = 0.041). CONCLUSION: Frailty was associated with a worsening in global alignment along the 2- year follow up. The frailty may begin with a decrease in activity and progression of exhaustion; preventing this progression is important through motivation to exercise. LEVEL OF EVIDENCE: II.

Clinical differences in preoperative symptoms and surgical outcomes between early and late-teen patients with Lenke type 5C adolescent idiopathic scoliosis.

PURPOSE: This study aimed to compare the clinical features and postoperative outcomes in patients with Lenke type 5C AIS in the early and late teens. METHODS: The study included eligible patients with AIS aged < 20 years with Lenke type 5C curves who underwent selective thoracolumbar/lumbar (TL/L) fusion. The patients were divided into two groups according to the age: younger (11-15 years) and older (16-19 years). Demographic data, radiographic parameters, and 22-item scoliosis research society questionnaire (revised) (SRS-22r) scores were compared. RESULTS: Seventy-three (female: 69, male: 4, mean age: 15.1 years) patients were included. There were 45 and 28 patients in the younger and older groups, respectively. The older group exhibited a significantly smaller TL/L curve than the younger group, whereas no between-group differences were identified regarding curve flexibility and fusion length. The change in coronal balance and subjacent disc angle from preoperative to 2 years after surgery was significantly greater in the younger group, although each curve was equally corrected. Preoperative SRS-22r scores in the older group were significantly worse; however, they improved to the level of the younger group at 2 years after surgery. Postoperative coronal malalignment was observed in six patients (21.4%) in the older group, whereas no cases in the younger group (p < 0.05). CONCLUSION: In patients with Lenke type 5C AIS, we showed that late teens had significantly worse SRS-22r scores than did early teens. Postoperative coronal malalignment was frequently observed in the late teens due to the reduced ability of compensation by subjacent disc wedging.

Prognostic impact of respiratory dysfunction in elderly patients with cervical spinal cord injury and/or fractures: a multicenter survey.

PURPOSE: To investigate the impact of early post-injury respiratory dysfunction for neurological and ambulatory ability recovery in patients with cervical spinal cord injury (SCI) and/or fractures. METHODS: We included 1,353 elderly patients with SCI and/or fractures from 78 institutions in Japan. Patients who required early tracheostomy and ventilator management and those who developed respiratory complications were included in the respiratory dysfunction group, which was further classified into mild and severe respiratory groups based on respiratory weaning management. Patient characteristics, laboratory data, neurological impairment scale scores, complications at injury, and surgical treatment were evaluated. We performed a propensity score-matched analysis to compare neurological outcomes and mobility between groups. RESULTS: Overall, 104 patients (7.8%) had impaired respiratory function. In propensity score-matched analysis, the respiratory dysfunction group had a lower home discharge and ambulation rates (p = 0.018, p = 0.001, respectively), and higher rate of severe paralysis (p < 0.001) at discharge. At the final follow-up, the respiratory dysfunction group had a lower ambulation rate (p = 0.004) and higher rate of severe paralysis (p < 0.001). Twenty-six patients with severe disability required respiratory management for up to 6 months post-injury and died of respiratory complications. The mild and severe respiratory dysfunction groups had a high percentage of severe paraplegic cases with low ambulatory ability; there was no significant difference between them. The severe respiratory dysfunction group tended to have a poorer prognosis. CONCLUSION: Respiratory dysfunction in elderly patients with SCI and/or cervical fracture in the early post-injury period reflects the severity of the condition and may be a useful prognostic predictor.

Effect of corrective stresses on rods in adult spinal deformity surgery-finite element analysis.

BACKGROUND: The incidence of rod fracture after corrective surgery for adult spinal deformity (ASD) is high. Although many reports have investigated the effects of rod bending considering postoperative body motion, and countermeasures, there are no reports investigating the effects during intraoperative correction. The purpose of this study was to investigate the effect of ASD correction on rods by using finite element analysis (FEA) based on the rod shape changes before and after spinal corrective fusion. METHODS: Five ASD patients (mean age 73 years, all female) who underwent thoracic to pelvic fusion were included in this study. A 3D rod model was created using computer-aided design software from digital images of the intraoperatively bended rod and intraoperative X-ray images after corrective fusion. The 3D model of the bent rod was meshed by dividing each of the screw head intervals into 20 sections and cross-section of the rod into 48 sections. Two surgical fusion methods of stepwise fixation as the cantilever method and parallel fixation as the translational method were simulated to evaluate stress and bending moments on the rods during intraoperative correction. RESULTS: The stresses on the rods were 1500, 970, 930, 744, and 606 MPa in the five cases for stepwise fixation and 990, 660, 490, 508, and 437 MPa for parallel fixation, respectively, with parallel fixation having lower stresses in all cases. In all cases, maximum stress was found around the apex of the lumbar lordosis and near L5/S1. The bending moment was high around L2-4 in most cases. CONCLUSIONS: The external forces of intraoperative correction had the greatest effect on the lower lumbar region, especially around the apex of the lumbar lordosis.

Symptoms of sacral fractures after posterior spinal instrumented fusion: A case series.

BACKGROUND: Improvements in spinal fusion devices and techniques have enabled stronger spinal fusion, resulting in excellent clinical outcomes. Nevertheless, complications associated with implants, such as screw misalignment, screw lubrication, cage dislocation, and skin issues, might occur. This study aimed to investigate the characteristics and symptoms of sacral fractures after spinal instrumented fusion. METHODS: This case series retrospectively examined the medical records of eight patients (one man and seven women; mean age: 74 years) diagnosed with sacral fractures after undergoing posterior spinal instrumented fusion from February 2015 to March 2022. RESULTS: The average number of fusion levels in all patients was 3.5 (range, 1-10). The lowest instrumented vertebrae (LIV) ranged from L5 to the ilium. Sacral fractures were diagnosed at 18.8 (range, 0.5-84) months postoperatively. The average time from consultation to diagnosis was nine days (range, 0-25 days). Two patients had subclinical fractures, two had H-shaped fractures with the LIV at L5, and four had U-shaped fractures, including screw holes. Buttock pain and lower extremity pain, the most commonly reported symptoms, were observed in seven patients each. There were also instances of leg numbness, muscle weakness, and unilateral leg pain that may be related to L5 or S1 radiculopathy. In all patients, leg and buttock pain were worse during movement and in the sitting position, and better while resting and in the supine position. Three patients were treated conservatively, and five were treated with extended fixation to the ilium. CONCLUSIONS: Sacral fractures following posterior spinal fusion can cause radiculopathy and buttock pain. Symptoms are especially severe when instability occurs in the pelvic region, such as during movements or sitting. As atypical radiculopathy may lead to delays in diagnosis, spine surgeons should recognize the symptoms of this condition.

Sex differences between the relationship of trunk muscle mass and whole body sagittal plane alignment in older adults.

BACKGROUND: This study aimed to clarify sex differences in the relationship between trunk muscle mass, aging, and whole-body sagittal alignment. METHODS: Subjects aged 60-89 years who underwent musculoskeletal screening in 2018 were included in the study. Subject demographics, trunk muscle mass (TMM) measured by bioelectrical impedance analysis (BIA), and spinopelvic and lower extremity alignment parameters measured from standing radiographic images were investigated. Additionally, TMM was corrected for BMI (TMM/BMI). The relationship between trunk muscle and whole-body sagittal alignment was analyzed for each age group (young-old group (60-74 years) and old-old group (>75 years)) and sex. RESULTS: A total of 281 (mean age 75.4 ± 6.7 years, 100 males and 181 females) were enrolled. The trunk muscle mass in both men and women significantly decreased with age. Regarding TMM/BMI, there was no significant difference in men, but there was a significant difference between females in the young-old and old-old groups (p < 0.001). TMM/BMI was significantly correlated with sagittal vertical axis (SVA) and knee flexion angle (KF) in both sexes. In females, TMM/BMI was significantly correlated with thoracic kyphosis in the young-old group, whereas in the old-old group, TMM/BMI was correlated with SVA, PI-LL, and KF. CONCLUSIONS: TMM was related to trunk anteverion and lower extremity alignment in both sexes. However, the relationship between TMM on alignment differs between sexes. Thoracic hyperkyphosis in young-old adults indicated a decrease in muscle mass, which may be a sign of future malalignment.

Characteristics of pedicle screw misplacement using freehand technique in degenerative scoliosis surgery.

PURPOSE: This study aimed to estimate the accuracy of pedicle screw (PS) placement in degenerative scoliosis surgery, characterize a patient population with PS misplacement, and analyze the association between misplaced PS vector and lumbar coronal curve. METHODS: In this study, 122 patients (average age 68.6 years), who underwent corrective and decompression surgery, were selected retrospectively. PS accuracy was evaluated in the thoracic to lumbar spine. We identified characteristics of misplacement in each patient. Screw positions were categorized into grade A, entirely in the pedicle; grade B, < 2 mm breach; grade C, 2-4 mm breach; and grade D, > 4 mm breach using postoperative computed tomography. RESULTS: The mean preoperative lumbar coronal curve was 32.3 ± 18.4°, and the number of fused vertebrae was 8.9 ± 2.8. A total of 2032 PS were categorized as follows: grade A, 1897 PS (93.3%); grade B, 67 (3.3%); grade C, 26 (1.3%); and grade D, 43 (2.1%). One PS (grade D), inserted at T5, needed surgery for removal due to neurological deficit. The misplacement group (grades C and D) had a significantly stronger lumbar coronal curve and apical vertebral rotation than the accuracy group (grades A and B). Misplaced PS vector (direction and degree) was significantly correlated with inserted vertebral rotation. Grade D misplacement was distributed mainly around the transitional vertebra of the lumbar curve. CONCLUSIONS: The accuracy of PS insertion in the thoracic to lumbar spine was high in DS surgery, but the need for care was highlighted in the transitional vertebra.

The validation study of preoperative surgical planning for corrective target in adult spinal deformity surgery with 5-year follow-up for mechanical complications.

PURPOSE: We used the Hamamatsu formula as an indicator of correction goals in surgery for adult spinal deformity (ASD). However, it is reported that correction according to Global Alignment and Proportion (GAP) score and the Roussouly algorithm reduces implant-related complications. The purpose of this study was to validate three preoperative plannings for the incidence of complications. METHODS: Patients who underwent ASD surgery and followed up for 5 years were included. The Hamamatsu formula was also divided into three groups: ideal (I), moderate (M), and under (U). The GAP score was divided into three groups: proportioned (P), moderately disproportioned (MD), and severely disproportioned (SD). Patients who met the postoperative Roussouly classification algorithm were defined as the restored (R) group and those who did not were defined as the non-restored (NR) group. Proximal junctional kyphosis (PJK) and rod fractures were investigated. RESULTS: In the Hamamatsu formula, there were 51, 108, and 44 patients in Groups I, M, and U, respectively, with no significant differences in their complications. In the GAP score, there were 45, 71, and 87 patients in the P, MD, and SD group, respectively, with no significant differences in their complications. In the Roussouly classification, there were 102 and 101 patients in the R and NR group, respectively, with a significant difference in their complication rate (R/NR = 51%:70%; P = 0.005). PJK was significantly lower in the R group (R/NR = 15%:30%; P = 0.010). CONCLUSION: Correction according to the Roussouly algorithm is useful for the prevention of mechanical complications, especially PJK.

Does surgery improve neurological outcomes in older individuals with cervical spinal cord injury without bone injury? A multicenter study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate the neurological outcomes of older individuals treated with surgery versus conservative treatment for cervical spinal cord injury (CSCI) without bone injury. SETTING: Thirty-three medical institutions in Japan. METHODS: This study included 317 consecutive persons aged ≥65 years with CSCI without bone injury in participating institutes between 2010 and 2020. The participants were followed up for at least 6 months after the injury. Individuals were divided into surgery (n = 114) and conservative treatment (n = 203) groups. To compare neurological outcomes and complications between the groups, propensity score matching of the baseline factors (characteristics, comorbidities, and neurological function) was performed. RESULTS: After propensity score matching, the surgery and conservative treatment groups comprised 89 individuals each. Surgery was performed at a median of 9.0 (3-17) days after CSCI. Baseline factors were comparable between groups, and the standardized difference in the covariates in the matched cohort was <10%. The American Spinal Injury Association (ASIA) impairment scale grade and ASIA motor score (AMS) 6 months after injury and changes in the AMS from baseline to 6 months after injury were not significantly different between groups (P = 0.63, P = 0.24, and P = 0.75, respectively). Few participants who underwent surgery demonstrated perioperative complications such as dural tear (1.1%), surgical site infection (2.2%), and C5 palsy (5.6%). CONCLUSION: Conservative treatment is suggested to be a more favorable option for older individuals with CSCI without bone injuries, but this finding requires further validation.

A multicenter study of 1-year mortality and walking capacity after spinal fusion surgery for cervical fracture in elderly patients.

BACKGROUND: The 1-year mortality and functional prognoses of patients who received surgery for cervical trauma in the elderly remains unclear. The aim of this study is to investigate the rates of, and factors associated with mortality and the deterioration in walking capacity occurring 1 year after spinal fusion surgery for cervical fractures in patients 65 years of age or older. METHODS: Three hundred thirteen patients aged 65 years or more with a traumatic cervical fracture who received spinal fusion surgery were enrolled. The patients were divided into a survival group and a mortality group, or a maintained walking capacity group and a deteriorated walking capacity group. We compared patients' backgrounds, trauma, and surgical parameters between the two groups. To identify factors associated with mortality or a deteriorated walking capacity 1 year postoperatively, a multivariate logistic regression analysis was conducted. RESULTS: One year postoperatively, the rate of mortality was 8%. A higher Charlson comorbidity index (CCI) score, a more severe the American Spinal Cord Injury Association impairment scale (AIS), and longer surgical time were identified as independent factors associated with an increase in 1-year mortality. The rate of deterioration in walking capacity between pre-trauma and 1 year postoperatively was 33%. A more severe AIS, lower albumin (Alb) and hemoglobin (Hb) values, and a larger number of fused segments were identified as independent factors associated with the increased risk of deteriorated walking capacity 1 year postoperatively. CONCLUSIONS: The 1-year rate of mortality after spinal fusion surgery for cervical fracture in patients 65 years of age or older was 8%, and its associated factors were a higher CCI score, a more severe AIS, and a longer surgical time. The rate of deterioration in walking capacity was 33%, and its associated factors were a more severe AIS, lower Alb, lower Hb values, and a larger number of fused segments.

Three-Dimensional Geometric Morphometry of Facial Soft Tissue Changes After Bilateral Sagittal Split Ramus Osteotomy.

ABSTRACT: This study aimed to evaluate the performance of geometric morphometry (GM) to assess the changes in facial soft tissue after orthognathic surgery. Subjects were 27 patients (skeletal class III) who underwent bilateral sagittal split ramus osteotomy and 27 volunteers as a control group. Computed tomography images of each patient were obtained before surgery (T0) and 6 months after surgery (T1). Computed tomography images of 27 volunteers (skeletal class I) were also obtained as a control group. Using a three-dimensional (3D) modeling software, 3D models were created and exported to a 3D surface analyzing software for geometric morphometry and principal component (PC) analysis. Significant differences in facial soft tissue were found in the first and second of 15 PC. The first PC represented variation in the lower facial height, and the second PC represented variation in the anterior-posterior position of the chin. Comparing the pre- and post-operative images, they illustrated that lower facial height was decreased, and the chin and lower lip moved posteriorly. Geometric morphometry showed to be a successful tool to isolate surgery-related changes from interindividual morphological variations.

Condoliase therapy for lumbar disc herniation -2 year clinical outcome.

BACKGROUND: Condoliase-induced chemonucleolysis is a less invasive treatment for lumbar disc herniation (LDH); however, its long-term clinical outcomes remain unclear. We investigated 2-year clinical outcomes and assess radiographs after chemonucleolysis with condoliase. METHODS: We enrolled patients with LDH who received condoliase therapy, with a minimum follow-up period of two years. Sixty-seven patients (44 men, 23 women; mean age, 46.7 ± 18.0 years) were analyzed. Time-course changes in disc height, disc degeneration, and herniation size were assessed. For clinical outcomes assessment, visual analog scale (VAS) scores for leg and back pain and the Oswestry disability index (ODI) were obtained at baseline and the 3-month, 1-year, and 2-year follow-ups. We obtained a questionnaire from these patients at two years to assess satisfaction and recommendation. Condoliase therapy was considered to be effective in patients whose VAS score for leg pain improved by ≥ 50% at 2 years from baseline and who did not require surgery. RESULTS: Condoliase therapy was effective in 51 patients (76.1%). Eight patients (11.9%) required surgery due to ineffectiveness of the therapy. Condoliase therapy was ineffective in five out of six patients with a history of discectomy. The ODI and VAS scores for leg and back pain significantly improved from three months to two years. Of the patients, 80% satisfied with their outcomes, and 85% recommended this therapy. Progression of disc degeneration was observed in 57.1% of patients at three months; however, 30% recovered to baseline at two years. The mean disc height decreased at three months, but recovered slightly at one year and remained stable until two years. No recurrent disc herniation was observed. CONCLUSIONS: Chemonucleolysis with condoliase was effective in 78% of patients with LDH for 2 years. Chemonucleolysis-induced disc degeneration was slightly recovered and maintained for two years post-injection. This treatment resulted in high patient satisfaction and recommendations.