The Influence of Titanium-coated Poryetheretherketone Cages in Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation.

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation (CBT-PLIF) shows potential for reducing adjacent segmental disease. Previously, our investigations revealed a relatively lower fusion rate with the use of carbon fiber-reinforced polyetheretherketone (CP) cages in CBT-PLIF compared with traditional pedicle screw fixation (PS-PLIF) using CP cages. This study aims to evaluate whether the implementation of titanium-coated polyetheretherketone (TP) cages can enhance fusion outcomes in CBT-PLIF. METHODS: A retrospective analysis was conducted on 68 consecutive patients who underwent CBT-PLIF with TP cages (TP group) and 89 patients who underwent CBT-PLIF with CP cages (CP group). Fusion status was assessed using computed tomography at 1 year postoperatively and dynamic plain radiographs at 2 years postoperatively. RESULTS: No statistically significant differences in fusion rates were observed at 1 and 2 years postoperatively between the TP group (86.8% and 89.7%, respectively) and the CP group (77.5% and 88.8%, respectively). Notably, the CP group exhibited a significant improvement in fusion rate from 1 to 2 years postoperatively (P = 0.002), while no significant improvement was observed in the TP group. CONCLUSIONS: Examination of temporal changes in fusion rates reveals that only the TP group achieved a peak fusion rate 1 year postoperatively. This implies that TP cages may enhance the fusion process even after CBT-PLIF. Nevertheless, the definitive efficacy of TP cages for CBT-PLIF remains uncertain in the context of overall fusion rates.

Predicting dry weight change in Hemodialysis patients using machine learning.

BACKGROUND: Machine Learning has been increasingly used in the medical field, including managing patients undergoing hemodialysis. The random forest classifier is a Machine Learning method that can generate high accuracy and interpretability in the data analysis of various diseases. We attempted to apply Machine Learning to adjust dry weight, the appropriate volume status of patients undergoing hemodialysis, which requires a complex decision-making process considering multiple indicators and the patient's physical conditions. METHODS: All medical data and 69,375 dialysis records of 314 Asian patients undergoing hemodialysis at a single dialysis center in Japan between July 2018 and April 2020 were collected from the electronic medical record system. Using the random forest classifier, we developed models to predict the probabilities of adjusting the dry weight at each dialysis session. RESULTS: The areas under the receiver-operating-characteristic curves of the models for adjusting the dry weight upward and downward were 0.70 and 0.74, respectively. The average probability of upward adjustment of the dry weight had sharp a peak around the actual change over time, while the average probability of downward adjustment of the dry weight formed a gradual peak. Feature importance analysis revealed that median blood pressure decline was a strong predictor for adjusting the dry weight upward. In contrast, elevated serum levels of C-reactive protein and hypoalbuminemia were important indicators for adjusting the dry weight downward. CONCLUSIONS: The random forest classifier should provide a helpful guide to predict the optimal changes to the dry weight with relative accuracy and may be useful in clinical practice.

Freehand screw insertion technique without image guidance for the cortical bone trajectory screw in posterior lumbar interbody fusion: what affects screw misplacement?

OBJECTIVE: Cortical bone trajectory (CBT) screw insertion using a freehand technique is considered less feasible than guided techniques, due to the lack of readily identifiable visual landmarks. However, in posterior lumbar interbody fusion (PLIF), after resection of the posterior anatomy, the pedicles themselves, into which implantation is performed, are palpable from the spinal canal and neural foramen. With the help of pedicle wall probing, the authors have placed CBT screws using a freehand technique without image guidance in PLIF. This technique has advantages of no radiation exposure and no requirement for expensive devices, but the disadvantage of reduced accuracy in screw placement. To address the problem of symptomatic breaches with this freehand technique, variables related to unacceptable screw positioning and need for revisions were investigated. METHODS: From 2014 to 2020, 182 of 426 patients with single-level PLIF were enrolled according to the combined criteria of L4-5 level, excluding cases of revision and isthmic spondylolisthesis; using screws 5.5 mm in diameter; and operated by right-handed surgeons. We studied the number of misplaced screws found and replaced during initial surgeries. Using multiplanar reconstruction CT postoperatively, 692 screw positions on images were classified using previously reported grading criteria. Details of pedicle breaches requiring revisions were studied. We conducted a statistical analysis of the relationship between unacceptable (perforations > 2 mm) misplacements and four variables: level, laterality, spinal deformity, and experiences of surgeons. RESULTS: Three screws in L4 and another in L5 were revised during initial surgeries. The total rate of unacceptable screws on CT examinations was 3.3%. Three screws in L4 and another in L5 breached inferomedial pedicle walls in grade 3 and required revisions. The revision rate was 2.2%. The percentage of unacceptable screws was 5.2% in L4 and 1.7% in L5 (p < 0.05), whereas other variables showed no significant differences. CONCLUSIONS: A freehand technique can be feasible for CBT screw insertion in PLIF, balancing the risks of 3.3% unacceptable misplacements and 2.2% revisions with the benefits of no radiation exposure and no need for expensive devices. Pedicle palpation in L4 is the key to safety, even though it requires deeper and more difficult probing. In the initial surgeries and revisions, 75% of revised screws were observed in L4, and unacceptable screw positions were more likely to be found in L4 than in L5.

Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial.

Importance: The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown. Objective: To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury. Design, Setting, and Participants: This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020. Interventions: Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment. Main Outcomes and Measures: The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury. Results: Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, -4.2 to 14.5; P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3]; P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%]; P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80; P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients). Conclusions and Relevance: These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation. Trial Registration: ClinicalTrials.gov Identifier: NCT01485458; umin.ac.jp/ctr Identifier: UMIN000006780.

Postoperative Loss of Lumbar Lordosis Affects Clinical Outcomes in Patients with Pseudoarthrosis after Posterior Lumbar Interbody Fusion Using Cortical Bone Trajectory Screw Fixation.

STUDY DESIGN: Retrospective cohort study. PURPOSE: This study aimed to investigate relationships between clinical outcomes and radiographic parameters in patients with pseudoarthrosis after posterior lumbar interbody fusion (PLIF). OVERVIEW OF LITERATURE: In some patients with pseudoarthrosis after PLIF, clinical symptoms improve following surgery, although pseudoarthrosis can often be one of the complications. However, there are no previous reports describing differences between patients with pseudoarthrosis after PLIF who have obtained better clinical outcomes and those who have not. METHODS: Twenty-seven patients who were diagnosed with pseudoarthrosis after single-level PLIF with cortical bone trajectory screw fixation (CBT-PLIF) were enrolled in this study. They were divided into two groups based on mean improvement of 22 points on the Oswestry Disability Index (ODI) at the 2-year follow-up. Group G consisted of 15 patients who showed improvement on the ODI of ≥22 points, and group P consisted of the residual 12 patients. Radiographic parameters, percentage of slip, lumbar lordosis (LL), segmental lordosis, segmental range of motion, screw loosening, and subsidence were compared between the two groups. RESULTS: There were no significant differences between the two groups on radiographic parameters except for postoperative changes in LL. Although surgery-induced changes in LL showed no significant difference between the two groups, changes in LL from before surgery to 2-year follow-up and during postoperative 2-year follow-up were significantly better in group G (mean change of LL: +3.5° and +5.1°, respectively) compared to group P (mean change of LL: -4.6° and -0.5°, respectively) (p<0.01 and 0.05, respectively). CONCLUSIONS: Patients with greater improvement in ODI gained LL over the 2-year follow-up, whereas patients with less improvement in ODI lost LL during the 2-year follow-up. These results indicate that there is a significant correlation between clinical outcomes and LL even in patients with pseudoarthrosis after single-level CBT-PLIF.

A rare case of nephrotic syndrome associated with Dent's disease: a case report.

Dent's disease is a rare X-linked condition caused by a mutation in CLCN5 and OCRL gene, which impair the megalin-cubilin receptor-mediated endocytosis in kidney's proximal tubules. Thus, it may manifest as nephrotic-range low-molecular-weight proteinuria (LMWP). On the other hand, glomerular proteinuria, hypoalbuminemia, and edema formation are the key features of nephrotic syndrome that rarely found in Dent's disease. Here, we reported a man in his 30 s with Dent's disease presented with leg edema for 5 days. The laboratory results revealed hypoalbuminemia and a decrease of urine ß2-microglobulin/urine protein ratio (Uß2-MG /UP), indicating that the primary origin of proteinuria shifted from LMWP to glomerular proteins. The kidney biopsy revealed glomerular abnormality and calcium deposition in the renal medulla. Electron microscopy of the kidney tissue indicated extensive foot-process effacement of the glomerular podocytes and degeneration of tubular epithelium. After a combination of treatment with prednisolone and cyclosporine (CyA), the nephrotic syndrome was remitted. Given the atypical clinical presentation and the shift of LMWP to glomerular proteinuria in this patient, glomerulopathy and the Dent's disease existed separately in this patient.

South Pacific influence on the termination of El Niño in 2014.

The El Niño/Southern Oscillation (ENSO) is the dominant mode of climate variability affecting worldwide extreme weather events; therefore, improving ENSO prediction is an important issue. In this regard, a peculiar time evolution of ENSO in 2014 posed a challenge to the climate science community. Despite the observance of several precursors for a strong El Niño to develop during the summer and autumn, cold sea surface temperature (SST) anomalies appeared unexpectedly to the south of the equatorial cold tongue, which prevented development of an El Niño event in the late summer. Several hypotheses have been raised to explain the unmaterialized El Niño in 2014, but complete understanding of processes responsible for terminating this event has not yet been obtained. Here we show, using observations and extended seasonal prediction experiments with a climate model, that cold off-equatorial subsurface water in the South Pacific Ocean penetrated into the equatorial region along the slanted isopycnal surface via the mean advection, and it prevented the El Niño evolution in 2014. The negative subsurface temperature anomalies in the off-equatorial South Pacific Ocean were persistent throughout the last decade, and additional numerical simulations indicated that they contributed to the suppression of El Niño events during the 2000s.

Skilful multi-year predictions of tropical trans-basin climate variability.

Tropical Pacific sea surface temperature anomalies influence the atmospheric circulation, impacting climate far beyond the tropics. The predictability of the corresponding atmospheric signals is typically limited to less than 1 year lead time. Here we present observational and modelling evidence for multi-year predictability of coherent trans-basin climate variations that are characterized by a zonal seesaw in tropical sea surface temperature and sea-level pressure between the Pacific and the other two ocean basins. State-of-the-art climate model forecasts initialized from a realistic ocean state show that the low-frequency trans-basin climate variability, which explains part of the El Niño Southern Oscillation flavours, can be predicted up to 3 years ahead, thus exceeding the predictive skill of current tropical climate forecasts for natural variability. This low-frequency variability emerges from the synchronization of ocean anomalies in all basins via global reorganizations of the atmospheric Walker Circulation.

Postoperative deep surgical-site infection after instrumented spinal surgery: a multicenter study.

A retrospective survey revealed 37 cases (1.1%) of deep surgical-site infection (SSI) among 3,462 instrumented spinal surgeries between 2004 and 2008. Excluding 8 patients who were unclassifiable, we categorized 29 patients into 3 groups of similar backgrounds-thoracolumbar degenerative disease (the DEG group; n = 15), osteoporotic vertebral collapse (the OVC group; n = 10), and cervical disorders (the cervical group; n = 4)-and investigated the key to implant salvage. Final respective implant retention rates for the groups were 40, 0, and 100%, with the OVC group having the worst rate (p < 0.01). In the DEG group with early infection, those whose implants were retained had lower body temperatures, lower white blood cell counts, and a lower rate of discharge at the time of SSI diagnosis (p < 0.05). Implant retention may be affected by initial spinal pathology. In the DEG group, debridement before drainage may be advantageous to implant salvage.

Deterioration of surgical outcomes with aging in patients with cervical spondylotic myelopathy.

STUDY DESIGN: : A retrospective investigation. OBJECTIVE: : To clarify at which age and at what point in the postoperative period neurological deterioration occurs in patients with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: : Inferior surgical outcomes tend to be seen with increasing age, however, the age threshold and the postoperative period associated with deterioration have not been established. METHODS: : Of 273 patients who underwent laminoplasty, 75 were enrolled in our study who met the criteria of having cervical spondylotic myelopathy, being monitored for a minimum of 2 years after surgery, and experiencing no morbidities within 2 years after surgery. Participants were classified into 4 age groups: group A, 54 years or below (n=12); group B, 55-64 years (n=22); group C, 65-74 years (n=24); and group D, 75 years or above (n=17). Preoperative physical status scores, using the American Society of Anesthesiologists (ASA) classification system, and neurological recovery, indicated by Japanese Orthopaedic Association (JOA) scores, were compared and surgical complications were reviewed. RESULTS: : The ASA physical status score was significantly lower in group A (1.4±0.5) than in group C (2.0±0.5) or group D (2.2±0.4) (P<0.0083). No difference was seen between the preoperative and 1-year postoperative JOA scores between the groups. However, the JOA score at ≥2 years after surgery was significantly lower in group D (12.9±2.0) than in group A (15.2±1.4; P<0.0083). Major complications of cardiopulmonary disorders were documented only in patients in groups C and D with A higher ASA scores. CONCLUSIONS: : Inferior surgical outcomes were seen in patients 75 years of age or above at 2 years after surgery compared with patients of 54 years or below of age. These clinical features could be reasonably explained by the patients' preexisting physical status related to age.

Robust warming of the global upper ocean.

A large ( approximately 10(23) J) multi-decadal globally averaged warming signal in the upper 300 m of the world's oceans was reported roughly a decade ago and is attributed to warming associated with anthropogenic greenhouse gases. The majority of the Earth's total energy uptake during recent decades has occurred in the upper ocean, but the underlying uncertainties in ocean warming are unclear, limiting our ability to assess closure of sea-level budgets, the global radiation imbalance and climate models. For example, several teams have recently produced different multi-year estimates of the annually averaged global integral of upper-ocean heat content anomalies (hereafter OHCA curves) or, equivalently, the thermosteric sea-level rise. Patterns of interannual variability, in particular, differ among methods. Here we examine several sources of uncertainty that contribute to differences among OHCA curves from 1993 to 2008, focusing on the difficulties of correcting biases in expendable bathythermograph (XBT) data. XBT data constitute the majority of the in situ measurements of upper-ocean heat content from 1967 to 2002, and we find that the uncertainty due to choice of XBT bias correction dominates among-method variability in OHCA curves during our 1993-2008 study period. Accounting for multiple sources of uncertainty, a composite of several OHCA curves using different XBT bias corrections still yields a statistically significant linear warming trend for 1993-2008 of 0.64 W m(-2) (calculated for the Earth's entire surface area), with a 90-per-cent confidence interval of 0.53-0.75 W m(-2).

Pacific decadal oscillation hindcasts relevant to near-term climate prediction.

Decadal-scale climate variations over the Pacific Ocean and its surroundings are strongly related to the so-called Pacific decadal oscillation (PDO) which is coherent with wintertime climate over North America and Asian monsoon, and have important impacts on marine ecosystems and fisheries. In a near-term climate prediction covering the period up to 2030, we require knowledge of the future state of internal variations in the climate system such as the PDO as well as the global warming signal. We perform sets of ensemble hindcast and forecast experiments using a coupled atmosphere-ocean climate model to examine the predictability of internal variations on decadal timescales, in addition to the response to external forcing due to changes in concentrations of greenhouse gases and aerosols, volcanic activity, and solar cycle variations. Our results highlight that an initialization of the upper-ocean state using historical observations is effective for successful hindcasts of the PDO and has a great impact on future predictions. Ensemble hindcasts for the 20th century demonstrate a predictive skill in the upper-ocean temperature over almost a decade, particularly around the Kuroshio-Oyashio extension (KOE) and subtropical oceanic frontal regions where the PDO signals are observed strongest. A negative tendency of the predicted PDO phase in the coming decade will enhance the rising trend in surface air-temperature (SAT) over east Asia and over the KOE region, and suppress it along the west coasts of North and South America and over the equatorial Pacific. This suppression will contribute to a slowing down of the global-mean SAT rise.

Absolute structure of panaxytriol.

Diastereomeric mixture at C-3 of (9R,10R)-panaxytriol acetonide (3) and (9S,10S)-panaxytriol acetonide (4) were enantioselectively acetylated to give (3R)-acetates (3a-Ac, 4a-Ac) and (3S)-alcohols (3b, 4b) by enzyme mediated-acetylation using CHIRAZYME and vinyl acetate, respectively. Hydrolysis of (3R)-acetate (3a-Ac, 4a-Ac) with CHIRAZYME and phosphate buffer afforded (3R)-alcohols (3a, 4a), respectively. Deprotection of panaxytriol acetonides (3a, 3b, 4a, 4b) gave panaxatriol and its isomers, respectively. Comparison of optical rotation values of the synthetic panaxatriols with that of the natural one confirmed that the absolute configuration of panaxytriol sould be 3R,9R,10R.