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Purpose: The AOSpine classification divides thoracolumbar burst fractures into A3 and A4 fractures; nevertheless, past research has found inconsistent interobserver reliability in detecting those two fracture patterns. This systematic analysis aims to synthesize data on the reliability of discriminating between A3 and A4 fractures.

Methods: We searched PubMed, Scopus, and the Web of Science for studies reporting the inter- and intra-observer reliability of detecting thoracolumbar AO A3 and A4 fractures using computed tomography (CT). The search spanned 2013 to 2023 and included both primarily reliability and observational comparative studies. We followed the PRISMA guidelines and used the modified COSMIN checklist to assess the studies' quality. Kappa coefficient (k) values were categorized according to Landis and Koch, from slight to excellent.

Results: Of the 396 identified studies, nine met the eligibility criteria; all were primarily reliability studies except one observational study. Interobserver k values for A3/A4 fractures varied widely among studies (0.19-86). The interobserver reliability was poor in two studies, fair in one study, moderate in four studies, and excellent in two studies. Only two studies reported intra-observer reliability, showing fair and excellent agreement. The included studies revealed significant heterogeneity in study design, sample size, and interpretation methods.

Conclusion: Considerable variability exists in interobserver reliability for distinguishing A3 and A4 fractures from slight to excellent agreement. This variability might be attributed to methodological heterogeneity among studies, limitations of reliability analysis, or diagnostic pitfalls in differentiating between A3 and A4. Most observational studies comparing the outcome of A3 and A4 fractures do not report interobserver agreement, and this should be considered when interpreting their results.

Background: Bone metastases can compromise the integrity of the spinal canal and cause epidural spinal cord compression (ESCC). The Spinal Instability Neoplastic Score (SINS) was developed in order to evaluate spinal instability due to a neoplastic process. The SINS has reached wide acceptance among clinicans but its prognostic value is still controversial. The aim was to investigate the correlation between the SINS and ESCC and the association between SINS and ambulation before and survival after surgery.

Methods: Correlations were assessed between SINS and grades of ESCC in patients who underwent spine surgery for spinal metastases. CT and MRI were used to calculate SINS and the grades of ESCC respectively. Correlations were analyzed with the Spearman’s correlation test. Postoperative survival was estimated with Kaplan-Meier analysis and survival curves were compared with the log-rank test. The Cox proportional hazard model was used to assess the effect of prognostic variables including age, ambulation before surgery, SINS, and the Karnofsky Performance Status (KPS) as covariates.

Results: The study included 256 patients (196 men and 60 women) with a median age of 70 (24–88) years. The mean SINS was 10. One hundred fifty-two patients (59%) had lost ambulation before surgery. One hundred and one patients had grades 0–2 and 155 patients had grade 3 according to the ESCC-scale. SINS correlated with the grades of ESCC (p = 0.001). The SINS score was not associated with ambulation before surgery (p = 0.63). The median postoperative survival was 10 months, and there was no difference in postoperative survival between the SINS categories (p = 0.25). The ability to walk before surgery and a high KPS were associated with longer postoperative survival.

Conclusion: SINS correlated with grades of ESCC, which implies that higher SINS may be considered as an indicator of risk for developing ESCC. The SINS was not associated with ambulation before or survival after surgery.

Purpose: Selective nerve root blocks (SNRB) are used both as a therapeutic and diagnostic tool for lumbar radicular pain. Most studies evaluate the effect of SNRB simply by its relation to pain reduction. It is well known that pain is associated with other factors such as depression, anxiety, inactivity and sleeping disorders, but these patient-related outcomes are seldom evaluated. This study evaluated the influence of SNRB on pain-related outcomes including depression, anxiety, fatigue, pain interference, activity and sleep.

Methods: One hundred three patients with lumbar radicular pain were treated with a SNRB. Patient-reported outcome measures (PROMs) were assessed with the PROMIS-29 for 12 weeks (84 days) following the SNRB. Patients were stratified based on their pain reduction at the 14-day follow up as responders (≥ 30% pain reduction) and non-responders (< 30% pain reduction). Post-treatment duration was estimated with the Kaplan–Meier analysis with return to baseline as an event. A paired t-test was used to compare pre- and post-treatment responses at specific time intervals.

Results: Forty-four percent (n = 45) of the patients were responders and showed significant improvement in all parameters throughout the 84-days follow-up, the exception was sleep that lost significance at day 70. The mean post-treatment duration among responders was 59 (52–67) days. Non-responders showed significant improvements in pain interference and pain intensity until day 35 and in ability for social participation until 21-day.

Conclusion: SNRB can improve pain intensity, pain interference, physical function, fatigue, anxiety, depression, sleep disturbance and the ability to participate in social roles.

Background: Low back pain, a common problem worldwide, causes more global disability than any other condition and is associated with high costs to society. This observational registry-based study describes the current trends in the medical treatment of neuropathic low back pain in the Swedish region of Västra Götaland, which has a population of 1.7 million. The study aims to; (1) identify the prevalence of neuropathic low back pain within the study population; (2) to explore the patterns of medical treatment utilization, including the prevalence and distribution of opioids (OG) and analgesics specified for neuropathic low back pain (NG) and (3) to evaluate the long-term trends and changes in medical treatment practice for neuropathic low back pain over the study period.

Methods: This study includes a descriptive analysis of aggregated data extracted from the Swedish primary care registry VEGA and the pharmaceutical prescription registry Digitalis between the years 2017 and 2021. The data were stratified by year, age, gender, pharmaceutical code (ATC), and sub-diagnoses and presented as the prevalence of unique patients retrieving prescribed medication within six months before or after a registered diagnosis of neuropathic low back pain. The pharmaceutical codes were furthermore grouped into two groups depending on their mechanism of action; opioid group (OG) and neuropathic group (NG).

Results: In all four diagnosis groups, more patients used opioid analgesics than neuropathic analgesics. The greatest difference between the opioid group and neuropathic group was in the lumbar spinal stenosis diagnosis group (67.1% vs. 40.6%), followed by the lumbar root canal stenosis diagnosis (65.9% vs. 44.2%), the nerve root and plexus compressions in intervertebral disc disorders diagnosis (57.5% vs. 40.8%), and lumbago with sciatica diagnosis (38.4% vs. 22.7%).

Conclusions: The trends suggest a general increase in the prescription rate and therefore patients’ use of neuropathic analgesics for neuropathic pain associated with the studied diagnoses. However, opioid treatment remains the most common. The results indicate that the treatment for neuropathic low back pain needs to be improved.

Spinal epidural hematomas (SEH) are a rare hemorrhagic event occurring after trauma, epidural anesthesia, or operative inventions. However, in 40–50% of cases, they occur spontaneously. Spontaneous spinal epidural hematomas (SSEH) are rare in occurrence with an estimated incidence of 1 case per million annually. Pregnancy is an independent risk factor. Sudden neck or back pain, often in combination with a rapid onset of neurological symptoms, is the most common presentation of SEH (1). A 36-year-old Caucasian female with rheumatoid arthritis (RA) presented to the emergency department approximately 48 h after an uncomplicated vaginal delivery. She sought medical attention due to constant headaches and neck pain that started during active labor. An MRI of the spine revealed an extensive SEH spreading from C1 to L5. The patient was without neurological symptoms or deficits and was successfully treated conservatively without any sequelae. Even though the definitive cause of this case of SEH will remain unknown, several possible synergistic mechanisms have been identified. These include female gender, full-term pregnancy, physical activity with increased intraabdominal pressure (i.e., Valsalva maneuver), systemic administration of platelet aggregation inhibitor (PAI), and iatrogenic manipulation such as spinal epidural anesthesia. Even though autoimmune and inflammatory disorders have been described in the literature to be rare sources of hemorrhage in the spinal canal, it is unclear whether the patient’s RA should be regarded as an individual risk factor.

BACKGROUND: Patients with lumbar spinal stenosis (LSS) sometimes have lower lumbar lordosis (LL), and the incidence of LSS correlates closely with the loss of LL. The few studies that have evaluated the association between LL and clinical outcomes after non-instrumented surgery for LSS show conflicting results. This study investigates the association between preoperative LL and changes in PROMs 2 years after decompressive surgery.

METHOD: This prospective cohort study obtained preoperative and postoperative data for 401 patients from the multicenter randomized controlled spinal stenosis trial as part of the NORwegian degenerative spondylolisthesis and spinal STENosis (NORDSTEN) study. Before surgery, the radiological sagittal alignment parameter LL was measured using standing X-rays. The association between LL and 2-year postoperative changes was analyzed using the oswestry disability index (ODI), a numeric rating scale (NRS) for low back and leg pain, the Zurich claudication questionnaire (ZCQ), and the global perceived effect (GPE) score. The changes in PROMs 2 years after surgery for quintiles of lumbar lordosis were adjusted for the respective baseline PROMs: age, sex, smoking, and BMI. The Schizas index and the Pfirrmann index were used to analyze multiple regressions for changes in PROMs.

RESULTS: There were no associations in the adjusted and unadjusted analyses between preoperative LL and changes in ODI, ZCQ, GPE, and NRS for back and leg pain 2 years after surgery.

CONCLUSION: LL before surgery was not associated with changes in PROMs 2 years after surgery. Lumbar lordosis should not be a factor when considering decompressive surgery for LSS.

With the aim of finding alternative reaction media for the synthesis of subvalent main group and transition metal cluster compounds, traditionally made through solid state reactions or in superacidic media, different alternative reaction media have been explored in this work. Room-temperature ionic liquids are amongst the more unconventional reaction media used. The syntheses performed have been aimed at both anionic and cationic cluster and the main tools used for characterization have been different X-ray diffraction and spectroscopic techniques.

Selected ionic liquids have along with dichloromethane been shown to work as alternative reaction media for room temperature synthesis of the Bi₅[GaCl₄]₃ salt. The salt containing the subvalent naked bismuth polycation Bi₅³⁺ was isolated from reduction reactions of BiCl₃ in Ga/GaCl₃-dichloromethane respectively Ga/GaCl₃-ioinc liquid media. Three different classes of ionic liquids based on phosphonium-, imidazolium- and pyrrolidinium- salts have been used in synthesis. Homopolyatomic clusters from the lighter Group 15 element arsenic have also been studied. Solutions from the oxidative and reductive reaction routes of arsenic and AsCl₃ in Lewis acidic toluene media were studied by EXAFS spectroscopy. The results were evaluated using molecular dynamics simulations of arsenic clusters. A discussion on how the calculated As4 cluster model relates to the experimental data resulted from this study.

In terms of homopolyatomic anionic clusters the [K⁺(2,2,2-crypt)]₂Ge₉^2- compound containing the naked Ge₉^2- anionic cluster has been isolated. The crystallographic investigation of [K⁺(2,2,2-crypt)]₂Ge₉^2- shows Zintl cluster anion Ge₉^2- to be tricapped trigonal-prismatic with a symmetry very close to D_3h. A chemical bonding analysis reveals two local minima of D_3h symmetry and the cluster interaction scheme to be based on highly delocalised bonding.

Ligand supported transition metal clusters from tungsten and palladium have also been prepared. Reduction of WCl₆ in a reaction mixture of ionic liquid and co-solvent toluene resulted in tritungsten decachloride; W₃Cl₁₀(MeCN)₃, being formed. Furthermore, palladium sandwich compounds; [Pd₂(Ga₂Cl₇)(C₇H₈)₂], [Pd₂(GaCl₄)(C₉H₁₂)₂]∙C₉H₁₂ and [Pd₂(Ga₂Cl₇)(C₆H₅Cl)₂] have been prepared using GaCl₃-arene reaction media.

Different synthetic approaches and modifications to reaction media have been applied in order to find new routes to the synthesis of main-group clusters and transition metal compounds. The focus has been on the Group 15 element bismuth and the transition metal palladium. The reactions performed have mainly been Lewis acid-base reactions and the characterization tools used X-ray diffraction and Raman spectroscopy.

The Bi₅[GaCl₄]₃ salt, previously known form synthesis using other reaction routes, has been isolated from GaCl₃-dichloromethane media. The salt containing the subvalent naked bismuth polycation Bi₅³⁺ was isolated from the reduction of bismuth(III) chloride. Quantum chemical calculations on the interaction energies of the isolated bismuth cluster show the dichloromethane-cluster interaction energy to be higher than that between benzene and the cluster.

Ionic liquids have, in addition to dichloromethane, been shown to work as alternative reaction media for room-temperature synthesis of the Bi₅[GaCl₄]₃ salt. Three different classes of ionic liquids have been used; phosphonium-, imidazolium- and pyrrolidinium-based salts. The ionic liquids used have been treated with Lewis acids in order to promote cluster formation.

In this work three new palladium sandwich compounds have also been isolated, using GaCl₃-arene reaction media; [Pd₂(Ga₂Cl₇)(C₇H₈)₂], [Pd₂(GaCl₄)(C₉H₁₂)2]∙C₉H₁₂ and [Pd₂(Ga₂Cl₇)(C₆H₅Cl)₂]. Quantum chemical calculations on these palladium sandwiches show the chlorobenzene sandwiching ligands unexpectedly interacting more strongly with the dipalladium unit than the methyl substituted arenes.

Background: Intraoperative (IO) image guidance surgery using 3-dimensional fluoroscopic navigation methods, such as the O-arm system, has improved the accuracy of pedicle screw placement in instrumented spine surgery. IO and postoperative (PO) validation of the implant’s correct position from radiological images is a decisive step to ensure patient safety and avoidance of complications related to implant misplacement. In this prospective single-center study, the authors investigated the accuracy and agreement of assessment of pedicle screws from IO O-arm images in comparison to PO computed tomography images. This study aimed to determine whether a final evaluation of pedicle screws can safely be conducted from IO images that supersede the PO computed tomography control.

Methods: A prospective single-center study was carried out at the Spine Unit in the Department of Orthopedics at Umeå University Hospital between 2019 and 2021. All patients enrolled in the study underwent instrumented thoracolumbar spine surgery using navigation. Imaging data were obtained from IO and PO examinations. Four reviewers—2 attending senior spine surgeons, 1 final year resident in orthopedics, and 1 attending neuroradiologist—classified pedicle screws using the Gertzbein and Robbins classification system. Agreement and accuracy of the reviewers were studied to evaluate the assessment of pedicle screws from IO and PO images.

Results: A total of 70 patients (422 screws) were included in the study. There was high accuracy among surgeons both on IO and PO images (0.96–0.97, 95% CI [0.94–0.99] and 0.97, 95% CI [0.94–0.99], respectively), and the overall agreement between all raters was 92% to 98% (95% CI [0.90, 1.00]). The discrepancy in assessment between optimal (Group 1) and suboptimal (Group 2) screws between IO and PO images was as low as 1% to 1.7%, which indicates that very few suboptimal screws are missed in the assessment of IO images.

Conclusions: The assessment of navigated pedicle screws using IO images is safe and reliable and may replace the need for further assessment using PO imaging.

The binuclear palladium(I) compounds, [Pd-2(Ga2Cl7)(2)(C7H8)(2)] (1), [Pd-2(GaCl4)(2)(C9H12)(2)]center dot C9H12 (2) and [Pd-2(Ga2Cl7)(2)(C6H5Cl)(2)] (3), have been prepared from palladium(II) chloride in gallium(III) chloride-arene reaction media. All isolated crystalline solids (1, 2 and 3) have been structurally characterized by single crystal X-ray diffraction and Raman spectroscopy. The results form quantum chemical calculations on the interaction energies of the arenes and the dipalladium unit of these compounds is also presented.

Following the development in the synthesis of subvalent cluster compounds, we report on the use of three different classes of room-temperature ionic liquids for the synthesis of the pentabismuth-tris(tetragallate) salt, Bi-5[GaCl4](3), characterized by X-ray diffraction. The Bi-5[GaCl4](3) salt was prepared by reduction of BiCl3 using gallium metal in ionic liquid reaction media containing a strong Lewis acid, GaCl3. The ionic liquids; trihexyltetradecyl phosphonium chloride [Th-Td-P+]Cl-, 1-dodecyl-3-methylimidazolium chloride [Dod-Me-Im(+)]Cl- and N-butyl-N-methylpyrrolidinium chloride [Bu-Me-Pyrr(+)]Cl- from three of the main classes of ionic liquids were used in synthesis. Reactions using ionic liquids composed of the trihexyltetradecyl phosphonium cation [Th-Td-P+] and the anions; tetrafluoroborate [BF4 (-)], bis(trifluoro-methyl sulfonyl) imide [(Tf)(2)N-] and hexafluorophosphate [PF6 (-)] were also investigated.

Atlantoaxial rotatory subluxation is an important differential diagnosis in young children with torticollis. The condition rarely results in neurological deficits. Radiological examinations such as computer tomography (CT) and magnetic resonance imaging (MRI) are useful to determine the diagnosis. It is important for doctors in all areas of healthcare to be aware of the condition, as persistent problems or surgery can be avoided by early detection and treatment.

[K(+)(2,2,2-crypt)] (2)Ge(9)(2-) containing the deltahedral Zintl anion Ge(9)(2-) has been isolated from a solution of K(4)Ge(9) in ethylenediamine in the presence of 2,2,2-crypt, intended as an intermediate in mixed-cluster synthesis. The subsequent crystallographic characterisation shows the closo-Ge(9)(2-) cluster unit to be tricapped trigonal-prismatic with a symmetry very close to D(3h). Each Ge(9)(2-) unit is surrounded by two 2,2,2-crypt units, each with a chelated K(+) cation, viz. [K(+)(2,2,2-crypt)]. The structure characterisation of this ordered Ge(9)(2-) cluster is surprisingly enough the first one reported. A chemical bonding analysis reveals two local minima of D(3h) symmetry, with that of lowest energy being highly similar to that resulting from the crystallographic analysis of low-temperature data. The cluster interaction scheme is based on highly delocalised bonding.

Study design: A prospective cohort study.

Objective: The aim was to investigate changes in lumbar lordosis (LL) and its association to changes in patient reported outcome measures (PROMs) after decompressive surgery for lumbar spinal stenosis (LSS).

Summary of background: Few studies have addressed change in LL after decompression surgery for LSS in relation to outcomes.

Method: Pre- and postoperative data from 310 patients having standing x-ray both before and 2 years after surgery were included. The patients were grouped based on the change in LL preoperatively to 2 years after surgery; group 1: <5 degrees (n=196), group 2: ≥5 <10 degrees (n=55) or group 3: ≥10 degrees (n=59) of change in LL. The changes in function, disability and pain were assessed by the Oswestry Disability Index (ODI), Numeric Rating Scale (NRS), and the Zurich claudication questionnaire (ZCQ). The three groups were compared regarding baseline variables using the ANOVA test for continuous variables and the chi-square test for categorical variables. The groups were further compared with a likelihood ratio test in relation to changes in PROMs 2 year after surgery and outcomes were adjusted for respective baseline PROMs, age, sex, smoking, BMI, Schizas and Pfirrmann scores.

Results: LL was significantly changed at group level 2 years after surgery with a mean difference of 2.2 (SD 9.4) degrees (P=0.001). The three LL change groups did not show any significant differences in patient characteristics, function, disability, and pain at baseline. The two groups with a change of more than 5 degrees in LL 2 year after surgery (group 2 and 3) had significantly greater improvements in ODI (P=0.022) and ZCQ function (P=0.016) in the adjusted analyses, but was not significant for back and leg pain

Conclusion: Changed LL after decompressive surgery for LSS was associated with improved ODI and physical function.

Dichloromethane (DCM), CH2Cl2 has been identified as an alternative reaction medium for room-temperature synthesis of subvalent homopolyatomic clusters of the group 15 element bismuth.