Pre-contoured patient-specific rods result in superior immediate sagittal plane alignment than surgeon contoured rods in adolescent idiopathic scoliosis.

Background: Adolescent idiopathic scoliosis (AIS) surgery typically involves posterior spinal fusion (PSF) using rods contoured by the surgeon, which may be time-consuming and may not reliably restore optimal sagittal alignment. However, pre-contoured patient-specific rods may more optimally restore sagittal spinal alignment. This study evaluates the radiographic outcomes of AIS patients who underwent PSF utilizing surgeon contoured vs. pre-contoured rods. Methods: This is a retrospective cohort study of AIS patients who underwent PSF with either surgeon contoured or pre-contoured rods. Demographics, Lenke classification, fused levels, osteotomies, estimated blood loss (EBL), and surgical time were also obtained via chart review. Coronal curve magnitude, T5-T12 thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, and T1 pelvic angle (TPA) were obtained pre-operatively, postoperatively and at last follow up. Outcome measures included rate of achievement of postoperative radiographic alignment goals (TK between 20 and 40 degrees, PI-LL mismatch within 10 degrees, and TPA <14 degrees). Predicted post-operative sagittal alignment was also compared with observed measurements. Student's and paired t-tests were performed to determine significant mean differences for continuous variables, and chi-square for categorical variables. Results: No differences were found in demographics, Lenke classification, preop radiographic measurements, fused levels, osteotomies, EBL, and surgical time in the surgeon contoured cohort (n=36; average follow up 11.3 months) and pre-contoured cohort (n=22; average follow up 9.7 months). At last follow up, 95.5% of patients with pre-contoured rods vs. 61.1% of patients with surgeon contoured rods (P=0.004) met TK goal. During assessment of first standing postoperative X-ray, 72.7% of patients with pre-contoured rods vs. 33.3% of patients with surgeon contoured rods met PI-LL mismatch goal (P=0.004). Other radiographic measurements were similar. Artificial intelligence (AI) predicted and observed differences for the pre-contoured group were 3.7 for TK (P=0.005), -7.6 for PI-LL mismatch (P=0.002), and -2.6 for TPA (P=0.11). Conclusions: AI and pre-contoured rods help achieve global sagittal balance with high accuracy and improved kyphosis restoration and PI-LL mismatch than surgeon contoured rods in AIS patients.

Selective Liquid-Liquid Extraction of Thorium(IV) from Rare-Earth Element Mixtures.

One of the major challenges in processing rare-earth element (REE) materials arises from the large amounts of radioactive thorium (Th) that are often found within REE minerals, encouraging enhanced metal separation procedures. We report here a study aimed at developing improved systems for REE processing with the goal of efficient extraction of Th(IV) from acidic solution. A tripodal ligand, TRPN-CMPO-Ph, was prepared that utilizes carbamoylmethylphosphine oxide (CMPO) chelators tethered to a tris(3-aminopropyl)amine (TRPN) capping scaffold. The ligand and its metal complexes were characterized by using elemental analysis, NMR, Fourier transform infrared spectroscopy, mass spectrometry, and luminescence spectroscopy. Using a liquid-liquid metal extraction protocol, TRPN-CMPO-Ph selectively extracts Th(IV) at an efficiency of 79% from a mixture of Th(IV), UO22+, and all rare-earth metal cations (except promethium) dissolved in nitric acid into an organic solvent. Th(IV) extraction selectivity is maintained upon extraction from a mixture that approximates a typical monazite leach solution containing several relevant lanthanide ions, including two ions at higher concentration relative to Th(IV). Comparative studies with a tris(2-aminoethyl)amine (TREN)-capped derivative are presented and support the need for a larger TRPN capping scaffold in achieving Th(IV) extraction selectivity.

Electron Paramagnetic Resonance, Electronic Ground State, and Electron Spin Relaxation of Seven Lanthanide Ions Bound to Lanmodulin and the Bioinspired Chelator, 3,4,3-LI(1,2-HOPO).

The electron paramagnetic resonance (EPR) spectra of lanthanide(III) ions besides Gd3+ , bound to small-molecule and protein chelators, are uncharacterized. Here, the EPR properties of 7 lanthanide(III) ions bound to the natural lanthanide-binding protein, lanmodulin (LanM), and the synthetic small-molecule chelator, 3,4,3-LI(1,2-HOPO) ("HOPO"), were systematically investigated. Echo-detected pulsed EPR spectra reveal intense signals from ions for which the normal continuous-wave first-derivative spectra are negligibly different from zero. Spectra of Kramers lanthanide ions Ce3+ , Nd3+ , Sm3+ , Er3+ , and Yb3+ , and non-Kramers Tb3+ and Tm3+ , bound to LanM are more similar to the ions in dilute aqueous:ethanol solution than to those coordinated with HOPO. Lanmodulins from two bacteria, with distinct metal-binding sites, had similar spectra for Tb3+ but different spectra for Nd3+ . Spin echo dephasing rates (1/Tm ) are faster for lanthanides than for most transition metals and limited detection of echoes to temperatures below ~6 to 12 K. Dephasing rates were environment dependent and decreased in the order water:ethanol>LanM>HOPO, which is attributed to decreasing librational motion. These results demonstrate that the EPR spectra and relaxation times of lanthanide(III) ions are sensitive to coordination environment, motivating wider application of these methods for characterization of both small-molecule and biomolecule interactions with lanthanides.

Effects of delayed ambulation following posterior spinal fusion for adolescent idiopathic scoliosis: a single institutional study.

OBJECTIVE: Mobilizing out of bed and ambulation are key components of recovery following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). However, there remains a paucity of studies identifying risk factors associated with delayed ambulation and its impact on postoperative outcomes. The aim of this study was to investigate patient- and surgical-level risk factors associated with delayed ambulation and the ramifications of delayed ambulation on healthcare utilization for patients undergoing PSF for AIS. METHODS: The medical records of 129 adolescent (10-18 years) patients diagnosed with AIS undergoing posterior spinal fusion at a major academic institution between 2013 and 2020 were reviewed. Patients were categorized based on days from surgery to ambulation: early (≤ 1 day), intermediate (2 days), or late (≥ 3 days). Patient demographics, comorbidities, spinal deformity characteristics, intraoperative variables, postoperative complications, LOS, and unplanned readmissions were assessed. The odds ratios for risk-adjusted delayed ambulation and extended LOS were determined via multivariate stepwise logistic regressions. RESULTS: One Hundred and Twenty Nine patients were included in this study, of which 10.8% (n = 14) were classified as Early ambulators, 41.9% (n = 54) Intermediate ambulators, and 47.3% (n = 61) were Late ambulators. Late ambulators were significantly younger than early and intermediate ambulators (Early: 15.7 ± 1.9 years vs. Intermediate: 14.8 ± 1.7 years vs. Late: 14.1 ± 1.9 years, p = 0.010). The primary and secondary spinal curves were significantly worse among Late ambulators (p < 0.001 and p = 0.002 respectively). Fusion levels (p < 0.01), EBL (p = 0.014), and the rate of RBC transfusions (p < 0.001) increased as time to ambulation increased. Transition time from IV to oral pain medications (Early: 1.6 ± 0.8 days vs. Intermediate: 2.2 ± 0.6 days vs. Late: 2.4 ± 0.6 days, p < 0.001) and total hospital length of stay (Early: 3.9 ± 1.4 days vs. Intermediate: 4.7 ± 0.9 days vs. Late: 5.1 ± 1.2 days, p < 0.001) were longer in Late ambulators. On multivariate analysis, significant predictors of delayed ambulation included primary curve degree ≥ 70° [aOR: 5.67 (1.29‒31.97), p = 0.030] and procedure time [aOR: 1.66 (1.1‒2.59), p = 0.019]. CONCLUSIONS: Our study suggests that there may be patient- and surgical-level factors that are independently associated with late ambulation following PSF for AIS, including extent of major curve and length of operative time. Additionally, delayed ambulation has implications to length of hospital stay and postoperative complications.

Association Between Intravenous to Oral Opioid Transition Time and Length of Hospital Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

BACKGROUND: Transitioning from intravenous (IV) to oral opioids after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) is necessary during the postoperative course. However, few studies have assessed the effects of longer transition times on hospital length of stay (LOS). This study investigated the impact of longer IV to oral opioid transition times on LOS after PSF for AIS. METHODS: The medical records of 129 adolescents (10-18 years old) with AIS undergoing multilevel PSF at a major academic institution from 2013 to 2020 were reviewed. Patients were categorized by IV to oral opioid transition time: normal (≤2 days) vs prolonged (≥3 days). Patient demographics, comorbidities, deformity characteristics, intraoperative variables, postoperative complications, and LOS were assessed. Multivariate analyses were used to determine odds ratios for risk-adjusted extended LOS. RESULTS: Of the 129 study patients, 29.5% (n = 38) had prolonged IV to oral transitions. Demographics and comorbidities were similar between the cohorts. The major curve degree (P = 0.762) and median (interquartile range) levels fused (P = 0.447) were similar between cohorts, but procedure time was significantly longer in the prolonged cohort (normal: 6.6 ± 1.2 hours vs prolonged: 7.2 ± 1.3 hours, P = 0.009). Postoperative complication rates were similar between the cohorts. Patients with prolonged transitions had significantly longer LOS (normal: 4.6 ± 1.3 days vs prolonged: 5.1 ± 0.8 days, P < 0.001) but similar discharge disposition (P = 0.722) and 30-day readmission rates (P > 0.99). On univariate analysis, transition time was significantly associated with extended LOS (OR: 2.0, 95% CI [0.9, 4.6], P = 0.014), but this assocation was not significant on multivariate analysis (adjusted OR: 2.1, 95% CI [1.3, 4.8], P = 0.062). CONCLUSIONS: Longer postoperative IV to oral opioid transitions after PSF for AIS may have implications for hospital LOS.

Impact of insurance status on healthcare resource utilization and outcomes in adolescent patients presenting with spinal cord injuries.

OBJECTIVE: Insurance disparities have been suggested to influence the medical and surgical outcomes of adult patients with spinal cord injury (SCI), with a paucity of studies demonstrating their impact on the outcomes of pediatric and adolescent SCI patients. The aim of this study was to assess the impact of insurance status on healthcare utilization and outcomes in adolescent patients presenting with SCI. METHODS: An administrative database study was performed using the 2017 admission year from 753 facilities using the National Trauma Data Bank. Adolescent patients (11-17 years old) with cervical/thoracic SCIs were identified using International Classification of Diseases, Tenth Revision, Clinical Modification coding. Patients were categorized by governmental insurance versus private insurance/self-pay. Patient demographics, comorbidities, imaging, procedures, hospital adverse events (AEs), and length of stay (LOS) data were collected. Multivariate regression analyses were used to determine the effect of insurance status on LOS, any imaging or procedure, or any AE. RESULTS: Of the 488 patients identified, 220 (45.1%) held governmental insurance while 268 (54.9%) were privately insured. Age was similar between the cohorts (p = 0.616), with the governmental insurance cohort (GI cohort) having a significantly lower proportion of non-Hispanic White patients than the private insurance cohort (PI cohort) (GI: 43.2% vs PI: 72.4%, p < 0.001). While transportation accident was the most common mechanism of injury for both cohorts, assault was significantly greater in the GI cohort (GI: 21.8% vs PI: 3.0%, p < 0.001). A significantly greater proportion of patients in the PI cohort received any imaging (GI: 65.9% vs PI: 75.0%, p = 0.028), while there were no significant differences in procedures performed (p = 0.069) or hospital AEs (p = 0.386) between the cohorts. The median (IQR) LOS (p = 0.186) and discharge disposition (p = 0.302) were similar between the cohorts. On multivariate analysis, with respect to governmental insurance, private insurance was not independently associated with obtaining any imaging (OR 1.38, p = 0.139), undergoing any procedure (OR 1.09, p = 0.721), hospital AEs (OR 1.11, p = 0.709), or LOS (adjusted risk ratio -2.56, p = 0.203). CONCLUSIONS: This study suggests that insurance status may not independently influence healthcare resource utilization and outcomes in adolescent patients presenting with SCIs. Further studies are needed to corroborate these findings.

Differences in Outcomes and Health Care Resource Utilization After Surgical Intervention for Metastatic Spinal Column Tumor in Safety-Net Hospitals.

STUDY DESIGN: Observational cohort study. OBJECTIVE: The aim of this study was to investigate the association between safety-net hospital (SNH) status and hospital length of stay (LOS), cost, and discharge disposition in patients undergoing surgery for metastatic spinal column tumors. SUMMARY OF BACKGROUND DATA: SNHs serve a high proportion of Medicaid and uninsured patients. However, few studies have assessed the effects of SNH status on outcomes after surgery for metastatic spinal column tumors. PATIENTS AND METHODS: This study was performed using the 2016-2019 Nationwide Inpatient Sample database. All adult patients undergoing metastatic spinal column tumor surgeries, identified using ICD-10-CM coding, were stratified by SNH status, defined as hospitals in the top quartile of Medicaid/uninsured coverage burden. Hospital characteristics, demographics, comorbidities, intraoperative variables, postoperative complications, and outcomes were assessed. Multivariable analyses identified independent predictors of prolonged LOS (>75th percentile of cohort), nonroutine discharge, and increased cost (>75th percentile of cohort). RESULTS: Of the 11,505 study patients, 24.0% (n = 2760) were treated at an SNH. Patients treated at SNHs were more likely to be Black-identifying, male, and lower income quartile. A significantly greater proportion of patients in the non-SNH (N-SNH) cohort experienced any postoperative complication [SNH: 965 (35.0%) vs . N-SNH: 3535 (40.4%), P = 0.021]. SNH patients had significantly longer LOS (SNH: 12.3 ± 11.3 d vs . N-SNH: 10.1 ± 9.5 d, P < 0.001), yet mean total costs (SNH: $58,804 ± 39,088 vs . N-SNH: $54,569 ± 36,781, P = 0.055) and nonroutine discharge rates [SNH: 1330 (48.2%) vs . N-SNH: 4230 (48.4%), P = 0.715) were similar. On multivariable analysis, SNH status was significantly associated with extended LOS [odds ratio (OR): 1.41, P = 0.009], but not nonroutine discharge disposition (OR: 0.97, P = 0.773) or increased cost (OR: 0.93, P = 0.655). CONCLUSIONS: Our study suggests that SNHs and N-SNHs provide largely similar care for patients undergoing metastatic spinal tumor surgeries. Patients treated at SNHs may have an increased risk of prolonged hospitalizations, but comorbidities and complications likely contribute greater to adverse outcomes than SNH status alone. LEVEL OF EVIDENCE: 3.

Impact of Racial Disparities on All-Cause Mortality in Patients With Tumors of the Spinal Cord or Spinal Meninges: A Propensity-Score Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The influence that race has on mortality rates in patients with spinal cord tumors is relatively unknown. The aim of this study was to investigate the influence of race on the outcomes of patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges. METHODS: The Surveillance, Epidemiology, and End Results (SEER) Registry was used to identify all patients with a code for primary malignant or nonmalignant tumor of the spinal cord (C72.0) or spinal meninges (C70.1) from 1973 through 2016. Racial groups (African-American/Black vs. White) were balanced using propensity-score (PS) matching using a non-parsimonious 1:1 nearest neighbor matching algorithm. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across non-PS-matched and PS-matched groups using log-rank tests. Associations of survival with clinical variables was assessed using doubly robust Cox proportional-hazards (CPH) regression analysis. RESULTS: There were a total of 7,498 patients identified with 648 (6.8%) being African American. African-American patients with primary intradural spine tumors were more likely to die of all causes than were White patients in both the non-PS-matched [HR: 1.26, 95% CI: (1.04, 1.51), P = 0.01] and PS-matched cohorts [HR: 1.64, 95% CI: (1.28, 2.11), P < 0.0001]. On multivariate CPH regression analysis age at diagnosis [HR: 1.03, 95% CI: (1.02, 1.05), P < 0.0001], race [HR: 1.82, 95% CI: (1.22, 2.74), P = 0.004), and receipt of RT [HR: 2.62, 95% CI: (1.56, 4.37), P = 0.0002) were all significantly associated with all-cause mortality, when controlling for other demographic, tumor, and treatment variables. CONCLUSIONS: Our study provides population-based estimates of the prognosis for patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges and suggests that race may impact all-cause mortality.

Prospective analysis of home narcotic consumption and management of excess narcotic prescription following adolescent idiopathic scoliosis surgery.

PURPOSE: The aim of this study was to identify factors associated with the outpatient narcotic intake of patients following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) and to introduce a safe and effective method of disposing of unused narcotics. METHODS: Following Institutional Review Board approval, retrospective review of prospectively collected data from patients undergoing PSF for AIS took place. Pain scores, narcotic use, patient demographic data, pre-, intra-, and postoperative parameters, and discharge data were gathered via chart review. Patients were divided into two groups according to home narcotic use, high use (top 25th percentiles) and low use (bottom 75th percentiles), and multivariate statistical analysis was conducted. Narcotic surplus was collected during postoperative clinic visits and disposed of using biodegradable bags. RESULTS: Statistical analysis of 27 patients included in the study showed that patients with a higher home narcotic use correlated with increased length of hospitalization with an average of 3.4 days compared to the lower-use group of 2.8 day (p = 0.03). Higher-use group also showed increased inpatient morphine milligram equivalent than the lower-use group. There was no significant difference of home narcotic use when looking at patient age, height, weight, BMI, levels fused, intraoperative blood loss, or length of surgery. A total of 502 narcotic doses were disposed of in the clinic. CONCLUSION: Our study suggests that there are not a significant number of patient- or surgical-level factors predisposing patients to increased home narcotic usage following spinal fusion for adolescent idiopathic scoliosis. LEVEL OF EVIDENCE: Level I, prospective study.