The Validation of the Japanese Version of the Scoliosis Research Society-30 Questionnaire for Adolescent Idiopathic Scoliosis Patients.

Introduction: The Scoliosis Research Society-30 (SRS-30) is a questionnaire originally developed from the SRS-22r questionnaire and is used to evaluate adolescent idiopathic scoliosis (AIS). It comprised questions on five domains: function, pain, self-image, mental health, and satisfaction, with seven additional questions related to postoperative aspects. In addition to the original English version, translations in multiple languages have been effectively applied. Herein, we evaluated the internal consistency and external validity of the Japanese version of the SRS-30 for AIS patients. Methods: Among the 30 questions in SRS-30, the eight additional questions from SRS-22r were translated and back-translated to create a Japanese version of the SRS-30. This translated questionnaire was then used to survey patients with AIS who underwent corrective fusion surgery one year postoperatively. The internal consistency of the responses was evaluated using the Cronbach α coefficient. Additionally, the Spearman correlation analyses were conducted to assess the correlation between the scores obtained from the SRS-30 Japanese version and SRS-22r and the Oswestry Disability Index (ODI) for the overall scale and the five domains. Results: A total of 81 cases (eight males and 73 females; mean age at surgery 14.4 years) were enrolled. The mean preoperative Cobb angle was 51.0°. The Cronbach α coefficient for the overall SRS-30 was 0.861, indicating high internal consistency, while the coefficients for each domain were as follows: function/activity, 0.697; pain, 0.405; self-image/appearance, 0.776; mental health, 0.845; and satisfaction, 0.559. The SRS-30 total score significantly correlated with the SRS-22r total (r=0.945, P<0.001) and the ODI (r=-0.511, P<0.001). The SRS-30 domains highly correlated with the corresponding SRS-22r domains, with correlations ranging from r=0.826 to 0.901 (all P<0.001). Conclusions: The Japanese version of the SRS-30 demonstrated good internal and external validity. The SRS-30 can be used as an assessment tool for health-related quality of life in AIS patients.

Evaluation of crankshaft phenomenon after posterior fusion for early onset scoliosis using an inverse trigonometric function: a multicenter retrospective cohort study.

PURPOSE: The crankshaft phenomenon (CSP) is a corrective loss after posterior surgery for early onset scoliosis (EOS). However, an accurate method for CSP evaluation has yet to be developed. In this study, we evaluated pedicle screw (PS) length and rotation angle using an inverse trigonometric function and investigated the prevalence of the CSP. METHODS: Fifty patients from nine institutions (mean age 10.6 years, male/female ratio 4:46) who underwent early definitive fusion surgery at ≤ 11 years of age were included. The rotation angle was calculated as arctan (lateral/frontal PS length) using radiography. Measurements were taken at the apex and lower instrumented vertebra (LIV) immediate, 2-, and 5-year postoperatively. CSP was defined as a rotation angle progression ≥ 5°. We divided patients into CSP and non-CSP groups and measured the demographic parameters, Risser grade, state of the triradiate cartilage, major coronal Cobb angle, T1-T12 length, T1-S1 length, and presence of distal adding-on (DAO). We compared these variables between groups and investigated the correlation between the measured variables and vertebral rotation. Logistic regression analysis investigated factors associated with CSP. RESULTS: The rotation angle progressed by 2.4 and 1.3° over 5 years for the apex and LIV, respectively. CSP occurred in 15 cases (30%), DAO in 11 cases (22%), and CSP and DAO overlapped in 4 cases (8%). In the CSP group, the T1-T12 length was low immediate postoperatively. The rotation angle was negatively correlated with preoperative height (r = - 0.33), T1-T12 length (r = - 0.35), and T1-S1 length (r = - 0.30). A lower preoperative T1-T12 length was associated with CSP (odds ratio: 0.996, p = 0.048). CONCLUSIONS: CSP occurred in 30% of patients with EOS who underwent definitive fusion. The presence of CSP was associated with a lower preoperative T1-T12 length. LEVEL OF EVIDENCE: Diagnosis, level IV.

Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs.

BACKGROUND: Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs). METHODS: We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery. RESULTS: The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference. CONCLUSIONS: We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

Radiation exposure in pediatric patients with early onset scoliosis: A longitudinal single-center study.

BACKGROUND: There is no consensus regarding the acceptable level of medical radiation exposure in patients with early-onset scoliosis. This study aimed to quantify radiation exposure in these patients and investigate factors associated with high exposure. METHODS: Patients with early-onset scoliosis who received care for their spine deformity and other comorbidities in our institution were retrospectively reviewed. Cumulative radiation exposure and total number of imaging studies were recorded. Patients with ≥30 mSv exposure were classified as high exposure and analyzed to clarify factors associated with high exposure. RESULTS: Thirty-five patients were included for analysis. The etiology of scoliosis was idiopathic in 8 patients, congenital in 7, syndromic in 8, and neuromuscular in 12. Fifteen patients underwent 19 spinal surgeries. The types of operation performed were definitive fusion (n = 12), vertebrectomy for hemivertebra (n = 2), growing rod (n = 1), lengthening (n = 3), and revision/partial implant removal (n = 1). The mean cumulative radiation dose was 22.3 mSv (range, 2.5-94.5 mSv). Spine radiography and computed tomography combined accounted for 15.0 mSv (range, 2.4-52.5 mSv, 67.3% of the mean cumulative dose). The mean radiation dose was significantly higher in patients who underwent spinal surgery than in those who did not (31.2 mSv vs. 15.6 mSv). The high-exposure group comprised 10 patients (1 idiopathic, 1 congenital, 5 syndromic, and 3 neuromuscular scoliosis) and 8 underwent 11 spinal operations. Among 8 patients who underwent spinal surgery, the cumulative radiation dose for spine was ≥30 mSv and spine computed tomography was performed an average of 4.0 times. CONCLUSIONS: Nearly one-third of patients with early-onset scoliosis and half of patients who underwent spinal surgery had >30 mSv radiation exposure due to multiple computed tomography. Medical radiation exposure and associated cancer risk should be considered when treating these patients.

Hypochnicium sensu lato (Polyporales, Basidiomycota) from Japan, with descriptions of a new genus and three new species.

Species of Hypochnicium (Polyporales, Basidiomycota) collected from Japan were studied on their taxonomy by morphological and phylogenetic approaches. Phylogenetic analyses based on a nrDNA LSU and ITS dataset including the Japanese specimens and other publicly available ones show that Hypochnicium is polyphyletic. Since the clade containing the type species H. bombycinum was well-supported, we defined this clade as Hypochnicium s. str., and emended Hypochnicium to include restricted taxa with only smooth basidiospores. The new genus Neohypochnicium is proposed to accommodate the remaining taxa excluded from the genus Hypochnicium s. str., which includes both species with smooth basidiospores and ornamented ones. Three new species, Gyrophanopsis japonica, N. asiaticum and N. perlongicystidiosum are described and illustrated based on morphological and phylogenetic analyses using an ITS region dataset. In addition, the following 15 new combinations are proposed: N. albostramineum, N. aotearoae, N. capitulateum, N. cremicolor, N. cystidiatum, N. geogenium, N. guineense, N. huinayense, N. michelii, N. microsporum, N. patagonicum, N. pini, N. punctulatum, N. subrigescens and N. wakefieldiae. An identification key to Japanese species of Bulbillomyces, Gyrophanopsis, Hypochnicium and Neohypochnicium is provided.

Predictors of Postoperative Delirium in Older Patients Undergoing Elective Spine Surgery.

Introduction: This prospective study was conducted to investigate the prevalence and predictors of postoperative delirium (POD) in a cohort of patients aged ≥65 years who were scheduled to undergo elective spine surgery. Methods: Patients aged ≥65 years who were scheduled to undergo elective spine surgery from February 2018 to May 2019 were prospectively recruited for this study. Delirium was diagnosed according to the Confusion Assessment Method algorithm. Candidate predictors included patient characteristics, comorbidities, surgical time, blood loss, preoperative laboratory parameters, and preoperative cognitive function, as assessed by the Mini-Cog test. These variables were compared between patients with and without POD. Multivariate logistic regression was performed to identify the independent predictors of POD. For the continuous variables, a receiver operating characteristic curve was used to determine the optimal cutoff value for predicting POD. Results: Of the 106 patients included in the study, 12 (11.3%) patients developed POD, with a median time to onset of 3 d and median duration of 2 d. After adjusting for confounders, the occurrence of POD was independently associated with older age, a higher blood urea nitrogen (BUN) concentration, and a lower Mini-Cog score. The optimal cutoff point of the Mini-Cog score for predicting the occurrence of POD was ≤3. Conclusions: POD was a common complication after spine surgery, showing an incidence of 11.3% in this study. Older age, a higher BUN concentration, and impaired cognition, as defined by the Mini-Cog, were independent predictors of POD. The current results may be useful for early identification of patients at risk of POD and facilitation of targeted interventions for preventing POD or mitigating its severity.

Incidence and causes of instrument-related complications after primary definitive fusion for pediatric spine deformity.

OBJECTIVE: Various complications have been reported in the treatment of pediatric spinal deformities. Among these, instrument-related complications could be critical concerns and risks of reoperation. This study aimed to identify the incidence and causes of complications after primary definitive fusion for pediatric spine deformities. METHODS: The authors retrospectively collected data from 14 institutions about patients who underwent primary definitive fusion between 2015 and 2017. There were 1490 eligible patients (1184 female and 306 male), with a mean age of 13.9 years. The incidence, causes, and reoperation rates were analyzed according to 4 etiologies of pediatric spine deformity (congenital, neuromuscular, syndromic, idiopathic). The complications were also categorized as screw-, hook-, or rod-related complications, implant loosening or backout, and junctional problems. RESULTS: The incidence of overall instrument-related complications was 5.6% (84 cases). Regarding etiology, the incidence rates were 4.3% (idiopathic), 6.8% (syndromic), 7.9% (congenital), and 10.4% (neuromuscular) (p < 0.05). The most common causes were pedicle screw malposition (60.7%), followed by implant backout or loosening (15.4%), junctional problems (13.1%), rod breakage (4.8%), and other complications (6.0%). Univariate analysis showed that etiology, type of deformity (kyphosis), surgical procedure, operation time, and estimated blood loss were significant factors. Multivariate analysis revealed that etiology (neuromuscular), surgical procedure (combined approach), and operation time (> 5 hours) remained as significant risk factors. Among all patients with instrument-related complications, 45% (38/84) required revision surgery. Of these cases, > 50% were related to pedicle screw malposition. Medial breach was the most common complication regardless of location, from upper thoracic to lumbar spine. CONCLUSIONS: Pedicle screw malposition was the primary cause of overall complications and subsequent reoperation. In addition to more precise screw insertion techniques, meticulous confirmation of pedicle screw placement, especially of medial breach, may reduce the overall instrument-related complications and revision rates.

Two new species of Sistotrema s.l. (Cantharellales) from Japan with descriptions of their ectomycorrhizae.

We describe two new species of resupinate Sistotrema sensu lato (Cantharellales) collected in Japan: S. flavorhizomorphae and S. chloroporum. Both species have urniform basidia with more than four sterigmata and monomitic hyphal system, oil-rich hyphae in subiculum, which is typical for this genus. Sistotrema chloroporum is characterized by poroid hymenophore partly yellowish-green, basidia 4-6-spored, medium-sized basidiospores (4.5-6.5 × 3.5-6 µm), and broadleaf forest habitat. Sistotrema flavorhizomorphae is characterized by hydnoid-irpicoid hymenophore, bright yellowish rhizomorphs, basidia 6-8-spored, small basidiospores (3-3.5 × 2.5-3 µm), and pine forest habitat. Phylogenetic trees inferred from the fungal nrDNA ITS and LSU and the rpb2 sequences supported that both species were distinct and grouped with other ectomycorrhizal Sistotrema and Hydnum species, but their generic boundary was unclear. Mycorrhizae underneath basidiomes of both species were identified and described via molecular techniques. Mycorrhizae of S. chloroporum have similar characteristics to those of other Sistotrema s.l. and Hydnum species, i.e., S. confluens and H. repandum, whereas S. flavorhizomorphae has a distinct morpho-anatomy, for example, a distinct pseudoparenchymatous mantle. Comprehensive characterizations of basidiomes and mycorrhizae improve the taxonomic analysis of mycorrhizal species of Sistotrema s.l.

Acute aortic occlusion after microendoscopic laminectomy in a patient with lumbar spinal stenosis: A case report.

RATIONALE: Acute aortic occlusion is an uncommon disease with a high morbidity and high mortality. Clinical symptoms typically include acute lower limb pain, acute paralysis, and absent pulses. We report a very rare case of acute aortic occlusion causing complete paralysis of bilateral lower limbs following microendoscopic laminectomy. PATIENT CONCERNS: A 64-year-old man with hypertension, hyperlipidemia, diabetes, and atrial fibrillation underwent microendoscopic laminectomy for lumbar spinal stenosis. After the operation, intermittent claudication improved significantly without neurological deficit. However, 7 days later, he developed complete paralysis of the bilateral lower limbs, extreme pain of the bilateral lower limbs, and mottling of the left extremity. DIAGNOSIS: An emergency magnetic resonance imaging examination revealed no epidural hematoma behind the spinal cord, proscribing spinal cord compression. Computed tomography revealed occlusion of the infrarenal abdominal aorta. Blood tests revealed high values of total plasminogen activator inhibitor-1 before surgery. INTERVENTIONS: The acute aortic occlusion was verified and underwent thrombectomy and right axillary-bifemoral bypass. OUTCOMES: Following the revascularization, the neurological deficit of the lower limbs improved. On follow-up after 1 year, the muscle strength of the bilateral lower limbs had returned to normal. LESSONS: This case presentation highlights the necessity of early diagnosis and early revascularization. Moreover, a preoperative high value of plasminogen activator inhibitor-1 may indicate vascular complications including Acute Aortic Occlusion.

Polygenic Risk Score of Adolescent Idiopathic Scoliosis for Potential Clinical Use.

Adolescent idiopathic scoliosis (AIS) is a common disease causing three-dimensional spinal deformity in as many as 3% of adolescents. Development of a method that can accurately predict the onset and progression of AIS is an immediate need for clinical practice. Because the heritability of AIS is estimated as high as 87.5% in twin studies, prediction of its onset and progression based on genetic data is a promising option. We show the usefulness of polygenic risk score (PRS) for the prediction of onset and progression of AIS. We used AIS genomewide association study (GWAS) data comprising 79,211 subjects in three cohorts and constructed a PRS based on association statistics in a discovery set including 31,999 female subjects. After calibration using a validation data set, we applied the PRS to a test data set. By integrating functional annotations showing heritability enrichment in the selection of variants, the PRS demonstrated an association with AIS susceptibility (p = 3.5 × 10-40 with area under the receiver-operating characteristic [AUROC] = 0.674, sensitivity = 0.644, and specificity = 0.622). The decile with the highest PRS showed an odds ratio of as high as 3.36 (p = 1.4 × 10-10 ) to develop AIS compared with the fifth in decile. The addition of a predictive model with only a single clinical parameter (body mass index) improved predictive ability for development of AIS (AUROC = 0.722, net reclassification improvement [NRI] 0.505 ± 0.054, p = 1.6 × 10-8 ), potentiating clinical use of the prediction model. Furthermore, we found the Cobb angle (CA), the severity measurement of AIS, to be a polygenic trait that showed a significant genetic correlation with AIS susceptibility (rg = 0.6, p = 3.0 × 10-4 ). The AIS PRS demonstrated a significant association with CA. These results indicate a shared polygenic architecture between onset and progression of AIS and the potential usefulness of PRS in clinical settings as a predictor to promote early intervention of AIS and avoid invasive surgery. © 2021 American Society for Bone and Mineral Research (ASBMR).

Clinical Results of Corrective Cast and Brace Treatment for Early-onset Scoliosis: The Effectiveness of Long-term Cast Treatment That Extends into Children's Schooldays.

BACKGROUND: Cast and brace treatment is a conservative treatment for early-onset scoliosis (EOS). We analyzed the clinical results of this treatment when extended into patients' schooldays. METHODS: Twenty-two children with EOS underwent alternatively repetitive cast and brace treatment (ARCBT). Cast was applied under general anesthesia and remained for some weeks, and the brace was continuously worn, which was repeatedly applied when scoliosis progressed. The change in the major curve angle, requirement for surgical intervention, and complications of ARCBT were analyzed. RESULTS: Six patients had idiopathic scoliosis (IS), 9 had syndromic scoliosis (SS), and 7 had neuromuscular scoliosis. Cast treatment started at 4.9±2.1 years of age, and the patients were followed up for 8.3 years. The average total number of cast applications was 5.5 per patient. The mean major scoliosis angle was 45.4±12.5 degrees at the first visit; this was corrected to 26.5±8.7 degrees at the first cast application and progressed to 75.4±22.1 degrees at the final visit. Nine patients whose scoliosis progressed finally underwent surgery. The mean age at surgery was 11.0 years (range, 8.8 to 13.1 y), and the mean period from first cast application to surgery was 6.1 years (range, 5.0 to 8.9 y). Four patients' IS rapidly progressed after 9 years of age, and all of them underwent final fusion surgery with a correction rate of 56.9%. Among patients with SS, 1 final fusion, and 2 growth-friendly surgeries were performed at a mean age of 9.2 years; the correction rate was 21.5%. Among patients with neuromuscular scoliosis, 2 final fusion surgeries were performed at a mean age of 11.3 years; the correction rate was 30.7%. The cast-related complication rate was 5.0%, and most complications were skin problems. CONCLUSIONS: Long-term ARCBT extended into schooldays might be effective for IS. This should be considered as a time-saving treatment option for EOS. LEVEL OF EVIDENCE: Level IV-case series.

Cobalt-chromium versus titanium alloy rods for correction of adolescent idiopathic scoliosis based on 1-year follow-up: a multicenter randomized controlled clinical trial.

OBJECTIVE: For instrumented correction surgery for adolescent idiopathic scoliosis (AIS), surgeons are increasingly switching from titanium (Ti) alloy rods to stiffer cobalt-chromium (CoCr) rods. The authors conducted the first multicenter randomized controlled clinical trial to investigate whether these materials affect the outcomes in terms of spine correction and quality of life (QOL). This trial was registered at UMIN Clinical Trials Registry on September 3, 2012, under the identifier UMIN000008838 (level of evidence 1). METHODS: Female AIS patients (Lenke types 1-3, patient age 10-19 years) were recruited at 5 Japanese institutions and randomized into two cohorts: 6.0-mm-diameter Ti rods were placed in one group, and 6.0-mm-diameter CoCr rods were placed in the other. Patients were followed up at 2 weeks and 3, 6, and 12 months with radiographic examination to quantify the sagittal and coronal correction (Cobb angle, thoracic kyphosis, rib hump, and apical vertebral rotation). Patients completed questionnaires (Scoliosis Research Society-22r, 12-Item Short-Form Health Survey, and Scoliosis Japanese Questionnaire-27) at 6 and 12 months to assess QOL. RESULTS: A total of 69 AIS patients were randomized to the demographically similar Ti (n = 37) or CoCr (n = 32) cohort. Four adverse events were recorded, two in each cohort, but these were not related to the rod material. At the final follow-up, both Ti and CoCr cohorts showed significant improvement in spinal correction, including the Cobb angle, thoracic kyphosis, and rib hump size. The correction rates were 68.4% and 67.1% for the Ti and CoCr cohorts, respectively. No parameters differed significantly between the cohorts at any time. Survey data showed improved but similar outcomes in both cohorts. CONCLUSIONS: Both treatments (Ti and CoCr) produced similar results and were efficient in engendering clinically significant spine corrections. Clinical trial registration no.: UMIN000008838 (UMIN Clinical Trials Registry).

Surgical Site Infection Following Primary Definitive Fusion for Pediatric Spinal Deformity: A Multicenter Study of Rates, Risk Factors, and Pathogens.

STUDY DESIGN: A retrospective multicenter study. OBJECTIVE: To determine the surgical site infection (SSI) rate, associated risk factors, and causative pathogens in pediatric patients with spinal deformity. SUMMARY OF BACKGROUND DATA: There have been no extensive investigations of the risk factors for SSI in Japan. METHODS: Demographic data, radiographic findings, and the incidence of SSI were retrospectively analyzed in 1449 pediatric patients who underwent primary definitive fusion surgery for spinal deformity at any of 15 institutions from 2015 to 2017. SSI was defined according to the US Centers for Disease Control and Prevention guideline. RESULTS: The incidence of all SSIs was 1.4% and that of deep SSIs was 0.76%. The most common pathogenic microbes were methicillin-resistant staphylococci (n = 5) followed by gram-negative rods (n = 4), methicillin-sensitive staphylococci (n = 1), and others (n = 10). In univariate analysis, younger age, male sex, a diagnosis of kyphosis, type of scoliosis, American Society of Anesthesiologists (ASA) class ≥3, mental retardation urinary incontinence, combined anterior-posterior fusion, greater magnitude of kyphosis, three-column osteotomy, use of blood transfusion, and number of antibiotic administration were associated with the likelihood of SSI (all P < 0.05). Multivariate logistic regression analysis identified the following independent risk factors for SSI: syndromic scoliosis etiology (vs. idiopathic scoliosis; adjusted odds ratio [OR] 16.106; 95% confidence interval [CI] 2.225-116.602), neuromuscular scoliosis etiology (vs. idiopathic scoliosis; adjusted OR 11.814; 95% CI 1.109-125.805), ASA class 3 (vs. class 2; adjusted OR 15.231; 95% CI 1.201-193.178), and administration of antibiotic therapy twice daily (vs. three times daily; adjusted OR 6.121; 95% CI 1.261-29.718). CONCLUSION: The overall infection rate was low. The most common causative bacteria were methicillin-resistant followed by gram-negative rods. Independent risk factors for SSI in pediatric patients undergoing spinal deformity surgery were scoliosis etiology, ASA class 3, and administration of antibiotic therapy twice daily.Level of Evidence: 3.

The complication trends of pediatric spinal deformity surgery in Japan - The Japanese Scoliosis Society Morbidity and Mortality survey from 2012 to 2017.

BACKGROUND: The Japanese Scoliosis Society Morbidity & Mortality Committee performed a longitudinal nationwide complication survey of spinal deformity surgery from 2012 to 2017. The present study aimed to analyze the survey results and report the complication trends of pediatric spinal deformity surgery in Japan. METHODS: All Japanese Scoliosis Society members were invited to participate in the survey. Diagnoses were grouped into idiopathic scoliosis, congenital scoliosis, neuromuscular scoliosis, other types of scoliosis, and pediatric kyphosis. Complications were grouped into death, blindness, neurological deficits (motor/sensory), infection, massive bleeding, hematoma, pneumonia, cardiac failure, deep vein thrombosis/pulmonary embolism, gastrointestinal perforation, and instrumentation failure. RESULTS: The surveys were performed in 2012, 2014, and 2017. The overall complication rate decreased from 10.7% in 2012 to 8.1% in 2017. In particular, the complication rate in patients with idiopathic scoliosis decreased from 8.8% in 2012 to 4.0% in 2017. The complication rate of patients with neuromuscular scoliosis and kyphosis remained high. The rate of neurological deficits, especially in motor deficits, significantly decreased from 2.0% in 2012 to 0.7% in 2017, and tended to be highest in patients with kyphosis. The rate of massive bleeding was significantly decreased from 3.3% in 2012 to 0.8% in 2017, especially in patients with neuromuscular scoliosis (12.2-4.4%). However, patients with neuromuscular scoliosis had a high rate of postoperative pneumonia (3.7%, 2.6%, and 5.1%, respectively). The rate of instrumentation failure was also high (2.1%, 1.5%, and 2.2%, respectively), especially in patients with early onset idiopathic, congenital and other types of scoliosis. CONCLUSIONS: The overall surgical complication rates in pediatric patients decreased due to decreased rates of neurological deficits and massive bleeding, especially in patients with idiopathic scoliosis. However, the complication rates remain high in patients with neuromuscular scoliosis and kyphosis.

The complication trends of adult spinal deformity surgery in Japan - The Japanese Scoliosis Society Morbidity and Mortality survey from 2012 to 2017.

BACKGROUND: The Japanese Scoliosis Society Morbidity & Mortality Committee performed a longitudinal nationwide complication survey of spinal deformity surgery from 2012 to 2017. The present study aimed to analyze the survey results and report the complication trends of adult spinal deformity surgery in Japan. METHODS: All Japanese Scoliosis Society members were invited to participate in the survey. Adult spinal deformity was categorized into three groups by age: 20-39 years, 40-64 years and ≥65 years. Complications were grouped into death, blindness, neurological deficits (motor/sensory), infection, massive bleeding, hematoma, pneumonia, cardiac failure, deep vein thrombosis/pulmonary embolism, gastrointestinal perforation, and instrumentation failure. RESULTS: The surveys were performed in 2012, 2014, and 2017. The overall complication rates were 21.6%, 26.0%, and 25.4%, respectively. The complication rates differed significantly by age group in all years such that older patients had a higher complication rate than younger patients. The rate of neurological deficits, particularly motor deficits, significantly increased in 2014 (3.1%-5.5%), and decreased in 2017 (4.3%). Massive bleeding and postoperative hematoma decreased significantly year by year (8.0%, 4.8%, 2.5% and 1.3%, 0.5%, 0.3%, respectively). The complication rate of instrumentation failure remained high, increasing without significant difference (5.2%, 5.8%, 6.5%, respectively), and was more common in the middle-aged and older patients. CONCLUSIONS: Surgical complication rates in patients with adult spinal deformity remain high, especially neurological deficits and instrumentation failure in patients aged over 40 years. However, the complication rates of massive bleeding and postoperative hematoma decreased over this period.

Incidence and Risk Factors for Unplanned Return to the Operating Room Following Primary Definitive Fusion for Pediatric Spinal Deformity: A Multicenter Study with Minimum 2-year Follow-Up.

STUDY DESIGN: A retrospective multicenter cohort study. OBJECTIVE: The aim of this study was to identify the incidence and risk factors for UPROR within minimum 2-year follow-up in primary definitive fusion for pediatric spinal deformity. SUMMARY OF BACKGROUND DATA: Several previous reports have elucidated the incidence of complications after pediatric scoliosis surgery; however, there has been no study that described the incidence and risk factors for unplanned return to the operating room (UPROR) with long-term follow-up in surgery for pediatric scoliosis with every etiology. METHODS: We retrospectively extracted data of patients aged <19 years, from 14 institutes in Japan, who underwent primary definitive fusion surgery for spinal deformity between January 1, 2015 and December 31, 2017. The primary outcomes were the incidence of UPROR within the minimum 2-year follow-up period for any reason. Univariate and multivariate logistical analyses were conducted to identify potential risk factors associated with UPROR. RESULTS: We identified 1417 eligible patients (287 males and 1130 females) with a mean age of 13.9 years. UPROR for any reason within minimum 2-year follow-up was identified in 68 patients (4.8%). The most frequent cause for UPROR was implant failure found in 29 patients, followed by surgical site infection in 14 patients, junctional problems in 10 patients, and neurological complications in six patients. The multivariate logistic regression analysis revealed that a diagnosis of kyphosis (odds ratio [OR], 2.65; 95% confidence interval [CI] 1.16-6.04), etiology of congenital or structural type (OR 2.21; 95% CI 1.08-4.53), etiology of syndromic type (OR 2.67; 95% CI 1.27-5.64), and increased operation time of ≥300 minutes (OR 1.81; 95% CI 1.07-3.07) were the risk factors for the incidence of UPROR. CONCLUSION: The present multicenter study identified for the first time the incidence and risk factors for UPROR with minimum 2-year follow-up after primary definitive fusion surgery for pediatric spinal deformity with every etiology.Level of Evidence: 3.

Impact of K-Line (-) in the Neck-Flexion Position on Patient-reported Outcomes After Cervical Laminoplasty For Patients With Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: This study was a post hoc analysis of prospective data. OBJECTIVE: The objective of this study was to investigate whether K-line (-) in the neck-flexion position [f-K-line (-)] affects patient-reported outcome measures after cervical laminoplasty for patients with ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND AND DATA: The f-K-line was recently proposed as a predictor of poor outcomes after laminoplasty for patients with OPLL. However, its impact on patient-reported outcome measures remains to be elucidated. PATIENTS AND METHODS: We analyzed prospectively collected data from 68 patients with cervical myelopathy due to OPLL who underwent double-door laminoplasty between 2008 and 2015. Patients were categorized into f-K-line (-) and f-K-line (+) groups on a baseline neck-flexion radiograph. Outcome measures included the Japanese Orthopaedic Association score, EuroQol 5-Dimensional Questionnaire, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, and 11-point Numerical Rating Scale for pain. The degree of satisfaction with the outcome was assessed at the 2-year follow-up using a 7-point Numerical Rating Scale. RESULTS: Of the 68 patients, 22 (32%) and 46 (68%) were grouped into the f-K-line (-) and f-K-line (+) groups, respectively. The 2 groups showed no significant difference in baseline functions. The f-K-line (-) group showed a significantly lower recovery rate of the Japanese Orthopaedic Association score and a significantly lower gain in EuroQol 5-Dimensional Questionnaire score than compared with the f-K-line (+) group at the 2-year follow-up. Among the 5 domains of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, cervical function, and upper extremity function were significantly lower in the f-K-line (-) group than in the f-K-line (+) group. Patients in the f-K-line (-) group also reported a significantly higher pain intensity in the upper and lower extremities and a significantly lower degree of satisfaction compared with those in the f-K-line (+) group. CONCLUSION: The f-K-line (-) was significantly associated with poorer functional recovery, higher pain intensity in the extremities, and lower patient satisfaction after cervical laminoplasty for patients with OPLL.

The Japanese Scoliosis Society Morbidity and Mortality Survey in 2014: The Complication Trends of Spinal Deformity Surgery from 2012 to 2014.

INTRODUCTION: The Japanese Scoliosis Society (JSS) created a longitudinal complication survey of spinal deformity surgery and established the Morbidity and Mortality (M&M) Committee in 2012. The purpose of this study was to analyze the results of the complication survey in 2014 and to report the differences in the complication rates between the years 2012 and 2014. METHODS: A request to participate in this survey was mailed to all JSS members. The questionnaires were sent through e-mail to the members who took part in this survey, and the responses were returned through the same. Diagnosis was grouped into idiopathic scoliosis, congenital scoliosis, neuromuscular scoliosis, spondylolisthesis, pediatric kyphosis and adult spinal deformity. Complication was grouped into death, blindness, neurological deficit (motor or sensory deficit), infection, massive bleeding, hematoma, pneumonia, cardiac failure, DVT/PE, gastrointestinal perforation and instrumentation failure. RESULTS: A total of 2,012 patients were reported from 71 institutes. Overall, complications were observed in 326 patients, and the complication rate increased from 10.4% in 2012 to 15.3% in 2014. The complication rate decreased from 8.8% to 3.7% in idiopathic scoliosis, 21.9% to 15.8% in neuromuscular scoliosis and 26.8% to 0% in kyphosis. The complication rate increased from 6.6% to 14.4% in congenital scoliosis, 9.3% to 12.0% in other types of scoliosis, 3.5% to 14.3% in spondylolisthesis and 21.6% to 26.0% in adult spinal deformity. The rate of neurological deficit, especially in motor deficit, increased from 3.2% to 7.7% in older patients with adult spinal deformity. Instrumentation failure was also more common in patients with adult spinal deformity (5.2% to 5.8%), especially in patients aged 40-65 years (4.4% to 9.1%). CONCLUSIONS: The major complication trends were an increasing rate of neurological deficit and instrumentation failure, especially in adult spinal deformity.

Bi-allelic loss of function variants of TBX6 causes a spectrum of malformation of spine and rib including congenital scoliosis and spondylocostal dysostosis.

BACKGROUND: Congenital scoliosis (CS) is a common vertebral malformation. Spondylocostal dysostosis (SCD) is a rare skeletal dysplasia characterised by multiple vertebral malformations and rib anomalies. In a previous study, a compound heterozygosity for a null mutation and a risk haplotype composed by three single-nucleotide polymorphisms in TBX6 have been reported as a disease-causing model of CS. Another study identified bi-allelic missense variants in a SCD patient. The purpose of our study is to identify TBX6 variants in CS and SCD and examine their pathogenicity. METHODS: We recruited 200 patients with CS or SCD and investigated TBX6 variants. We evaluated the pathogenicity of the variants by in silico prediction and in vitro experiments. RESULTS: We identified five 16p11.2 deletions, one splice-site variant and five missense variants in 10 patients. In vitro functional assays for missense variants identified in the previous and present studies demonstrated that most of the variants caused abnormal localisation of TBX6 proteins. We confirmed mislocalisation of TBX6 proteins in presomitic mesoderm cells induced from SCD patient-derived iPS cells. In induced cells, we found decreased mRNA expressions of TBX6 and its downstream genes were involved in somite formation. All CS patients with missense variants had the risk haplotype in the opposite allele, while a SCD patient with bi-allelic missense variants did not have the haplotype. CONCLUSIONS: Our study suggests that bi-allelic loss of function variants of TBX6 cause a spectrum of phenotypes including CS and SCD, depending on the severity of the loss of TBX6 function.