Successful Fusion Research Articles

A Lateral Expandable Cage with Independently Adjustable Anterior and Posterior Heights Can Improve the Pressure Distribution at the Cage-Endplate Interface: A Biomechanics Study

ObjectiveThis study investigated how the expansion trajectory of a lateral expandable cage affects pressure distribution at the cage-endplate interface under well-controlled biomechanical loading conditions. MethodsThree unique vertical height expansion trajectories used by clinically relevant lateral expandable cages were evaluated: craniocaudal, fixed-arc, and independently-adjustable anterior and posterior (IAP) height expansion. Two biomechanical loading scenarios were performed. The first scenario used custom bone foam test blocks to assess resultant pressure distribution at varying test block lordotic angles and expansion heights. The second scenario performed simulated expansion using synthetic spine units and compared the pressure distribution following expansion. ResultsFor an expandable cage with craniocaudal expansion, the pressure distribution at the cage-endplate interface was found to be heavily dependent on the lordotic angle of the test block (p<0.001) but not expansion height (p=0.634). The greatest maximum pressure occurred at higher test block lordotic angles. For an expandable cage with fixed-arc expansion, the pressure distribution shifted anteriorly throughout expansion. In the simulated expansion trials, an expandable cage with IAP expansion was found to improve the pressure distribution at the cage-endplate interface reducing the maximum pressure measurements by 22% and 14% compared to the craniocaudal and fixed-arc expansion respectively. ConclusionsOf the cage designs evaluated within this study, an expandable cage with independently adjustable anterior and posterior heights lowered the maximum pressure measured at the cage-endplate interface and alleviated the potential of cage edge loading, both important considerations fundamental for a successful fusion procedure and the mitigation of implant subsidence risk.

Effect of Mixture of Recombinant Human Bone Morphogenic Protein-2 and Demineralized Bone Matrix in Lateral Lumbar Interbody Fusion.

This study aims to determine the optimal dose of recombinant-human bone morphogenic protein-2 (rhBMP-2) for successful bone fusion in minimally invasive lateral lumbar interbody fusion (MIS LLIF). Previous studies show that rhBMP is an effective alternative to autologous iliac crest bone graft, but the optimal dose remains uncertain. The study analyzes the fusion rates associated with different rhBMP doses to provide a recommendation for the optimal dose in MIS LLIF. Ninety-three patients underwent MIS LLIF using demineralized bone matrix (DBM) or a mixture of rhBMP-2 and DBM as fusion material. The group was divided into the following three groups according to the rhBMP-2 usage : group A, only DBM was used (n=27); group B, 1 mg of rhBMP-2 per 5 mL of DBM paste (n=41); and group C, 2 mg of rhBMP-2 per 5 mL of DBM paste (n=25). Demographic data, clinical outcomes, postoperative complication and fusion were assessed. At 12 months post-surgery, the overall fusion rate was 92.3% according to Bridwell fusion grading system. Groups B and C, who received rhBMP-2, had significantly higher fusion rates than group A, who received only DBM. However, there was no significant increase in fusion rate when the rhBMP-2 dosage was increased from group B to group C. The groups B and C showed significant improvement in back pain and Oswestry disability index compared to the group A. The incidence of screw loosening was decreased in groups B and C, but there was no significant difference in the occurrence of other complications. Usage of rhBMP-2 in LLIF surgery leads to early and increased final fusion rates, which can result in faster pain relief and return to daily activities for patients. The benefits of using rhBMP-2 were not significantly different between the groups that received 1 mg/5 mL and 2 mg/5 mL of rhBMP-2. Therefore, it is recommended to use 1 mg of rhBMP-2 with 5 mL of DBM, taking both economic and clinical aspects into consideration.

Minimally Invasive Surgery vs Open Approach to First Metatarsophalangeal Joint Arthrodesis: A Comparison of Surgical Outcomes

Category: Midfoot/Forefoot; Other Introduction/Purpose: Minimally invasive surgery (MIS) is becoming increasingly popular among foot and ankle orthopaedic surgeons, as it has been shown to have limited complication rates and faster recovery times. Although there is robust data on MIS to treat hallux valgus, few studies have evaluated the role of MIS for 1st metatarsophalangeal (MTP) fusion to treat hallux rigidus - the most common arthritis of the foot. Hallux rigidus affects 2.5% of the U.S. population over age 50. Given this disease prevalence, it is important to characterize outcomes following MTP fusion procedures to optimize surgical approaches. In this retrospective cohort study, we aim to compare (1) patient-reported pain, (2) rate of successful fusion, and (3) rate of complications between groups who underwent open or MIS 1st MTP arthrodesis. Methods: This retrospective cohort study was conducted by evaluating clinical metrics, surgical outcomes, and radiographic data through chart review of 78 patients (25 male, 53 female), who underwent a 1st MTP fusion procedure at a large urban academic medical center from July 2015 through January 2023. 71 patients had a diagnosis of hallux rigidus, with other common diagnoses including hammertoe (24), hallux valgus (24), additional arthritides (11), and metatarsalgia (11). Two patients were excluded from our analysis due to lack of sufficient orthopaedic follow-up preventing evaluation of joint fusion. Pre- and post-operative pain scores were recorded on a 0-10 scale, though some notes documented subjective experience of pain (e.g., “minimal”). Complications were identified using post-operative clinic notes. The following radiographic data were included: hallux valgus angle, intermetatarsal angle, Coughlin classification, presence of arthritis, pre-operative sesamoid position, fusion construct materials, and success of fusion. Results: Of the 80 1st MTP fusion surgeries (two patients received both left and right foot operations), 51 were open and 29 were minimally invasive. There was no significant difference in the change in pre- to post-operative pain between the two groups (p=0.39). MIS patients had a higher successful fusion rate (100.0%) when compared to open surgery patients (94.1%), though this difference was insignificant (p=0.55). There was no significant difference in overall complication rates between MIS and open surgery groups (p=0.79). However, the MIS patients did not have any cases of deep infection or wound dehiscence and all (5/5) of their complications were related to hardware removal after fusion, whereas half of the complications (5/10) for the open surgery patients were related to infection and wounds. Conclusion: This retrospective analysis of 78 patients treated for hallux rigidus with 1st MTP fusion surgery showed no significant difference in rates of successful fusion and complications among patients who received an MIS procedure compared to an open surgery. There was no difference in patient-reported pain improvement between the two groups. Our main limitation is provider specialization, as only one surgeon in this study performed the MIS cases. Further studies should be done to obtain higher-level evidence to elucidate potential benefits of MIS over open surgery for 1st MTP arthrodesis.

Influence of Retrograde Intramedullary Beam Position Within Talar Body on Radiographic Failure of Medial Column Fusion

Category: Midfoot/Forefoot; Diabetes Introduction/Purpose: Intramedullary fixation in the form of retrograde beam or bolt has developed as an intriguing treatment option for unstable midfoot collapse. This is particularly true when it is desired to minimize the length of incision or to avoid surface implants in a compromised soft tissue envelope. However, prior studies have demonstrated high rates of complications associated with intramedullary midfoot fusion constructs (Ford et al., Butt et al). The goal of this study was to create a reproducible convention of classifying position of the terminal implant within the talar body and to uncover an association of relative position of the implant at the time of surgery with an increased risk of failure. Methods: Consecutive patients treated surgically from January 2017 to September 2022 with retrograde intramedullary fusion beam were identified; 44 were included in the final analysis. Average age was 62.7 years and mean radiographic follow up measured 12.86 months. Figure 1 demonstrates our classification of relative talar position. First, a line was drawn along the axis of the talar neck and carried posteriorly dividing the talar body into dorsal and plantar hemispheres. Then, a line was drawn from the anterior articular margin of the talar body to the lateral talar process. Parallel lines were then created in an equidistant fashion to divide the talar body into equal relative quartiles. At the time of surgery, the tip of the intramedullary beam was classified into relative axial and coronal position by a single observer. Our primary outcomes were hardware failure defined by implant fracture or cutout from the bone or additional surgery. Results: Successful midfoot fusion with intramedullary beam was achieved in 77% of our cases. 10 cases demonstrated hardware failure or the need for additional surgery. Relative implant position was classified as dorsal in 43% of cases and plantar in 57% of cases. Talar quartile depth was classified as 1st in 6% cases, 2nd in 32% of cases, 3rd in 30% of cases, and 4th in 32% of cases. There was no clinical or statistically significant difference between rates of failure based on relative implant position. Conclusion: Retrograde intramedullary fusion for medial column collapse remains a viable treatment option and our data supports successful fusion in most patients but a risk of failure remains significant. In this study, the relative position of the terminal implant within the talar body did not correlate with an increased risk of failure. There are likely other patient specific, or biomechanical factors leading to hardware fracture, cut out, or return of deformity. Continued analysis as sample size increases remains paramount to forming additional conclusions.

Fusion Rates in Tibiotalocalcaneal Arthrodesis with Tantalum Coated Metal Cup Augmentation

Category: Ankle Arthritis; Ankle Introduction/Purpose: Tantalum coated metal spacers (TCMS) have recently been utilized to fill and provide structure to large bony defects in the hindfoot. TCMS have a porous structure and elastic modulus similar to cancellous bone, increasing resistance to collapse, as well as osteoconductive properties that allow for bony ingrowth. At this time, there is still a paucity of literature assessing the use and outcomes of TCMS in foot and ankle surgery, more specifically as bridging structures for large bony defects when performing tibiotalocalcaneal (TTC) arthrodesis. This study serves to assess clinical outcomes and fusion rates of patients who underwent TTC arthrodesis utilizing intramedullary nailing with tantalum coated metal cup augmentation for large bony defects. Methods: We retrospectively reviewed the charts of 20 patients who underwent TTC fusion with TCMS augmentation at our local tertiary care center between 2015-2021. The CT scans at the six-month post-operative window were reviewed by one orthopaedic surgeon to determine the presence of bony fusion, which was defined as having at least 50% fusion mass. From the initial cohort, we collected the following modified foot function index scores for 13 patients: PROMIS Physical Health (0-20), PROMIS Mental health (0-20), Foot Function Index (0-170), Activity Limitation Scale (0-30), Pain Scale (0-50) and Disability Scale (0-90). Results: The mean age of our cohort was 53.9 (± 12.9) with a mean CCI of 1.54 (± 1.127) and mean follow up of 451.5 days (± 353.3). Mean modified foot function index scores included: PROMIS Physical Health 12.15 (± 3.34), PROMIS Mental health 12.23 (± 4.82), Foot Function Index 91.08 (± 47.59), Activity Limitation Scale 15.00 (± 10.42), Pain Scale 25.00 (± 14.77) and Disability Scale 51.00 (± 25.06). The post-operative complication rate was 30.8% in which 3 patients required a revision surgery via nail dynamization and one patient required a below knee amputation due to an infected nonunion of the TTC arthrodesis. The overall fusion rate at the 6-month postoperative visit was 69.2%. Conclusion: Unlike prior studies, we were able to obtain 6-month post-operative CT scans to delineate successful fusions with a larger number of patients (n=13). Given the paucity of literature looking at TCMS augmented fusions in foot and ankle surgery, our data will contribute to our understanding and efficaciousness of this relatively new use of TCMS in foot and ankle surgery. Further studies are needed to evaluate the efficacy of TCMS augmented fusions as a viable surgical approach as well an alternative to standard nail dynamizations with structural grafts.

Adjacent Joint Arthritis Incidence Rate Following Fusion of the First Tarsometatarsal Joint as Treatment for a Forefoot Deformity

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Nontraumatic forefoot deformities such as hallux valgus (HV) are common causes for patients seeking reconstructive surgery. Known as a “bunion,” HV is characterized by 1-2 intermetatarsal angle widening and first metatarsal head medial drift, resulting in the great toe pointing laterally. Surgery is indicated for patients who fail to find relief with conservative management. However, there is no consensus among orthopedic surgeons on whether osteotomy or first tarsometatarsal (TMT) arthrodesis is the better surgical treatment method. Additionally, no known studies have explored the development of adjacent joint arthritis in patients who have received a first TMT fusion. This study aims to investigate the rate of arthritis development in the adjacent joints following arthrodesis of the first TMT joint. Methods: A retrospective chart review at a tertiary foot and ankle clinic was performed on subjects who received a first TMT fusion between January 2004 and December 2017. This included subjects who received concomitant gastrocnemius recession, tendo-achilles lengthening, 1-2 intermetatarsal arthrodesis, 1-2 intercuneiform arthrodesis, hammertoe corrections, and other soft tissue releases deemed by the senior authors to be inconsequential in the case of adjacent joint arthritis development. Pre- operative, operative, and post-operative indications will be evaluated throughout this thorough chart review, and charts will be continually reviewed for inclusion and exclusion criteria. Patient information gathered includes age, sex, height, weight, BMI, activity level, smoking history, medications, time spent with hardware retained, the method of arthritis diagnosis (x-ray alone, CT, MRI, bone scan), relevant additional diagnoses, and operative data. Pre- and post-operative pain levels and satisfaction scores will follow the AOFAS Score Criteria. Results: Preliminary Results: 899 subjects (148 males, 751 females) are included in this study. The age range was 67 years (18 - 85), with an average age of 56.6 at surgery. Patient BMI varied from 12.7 to 53.1. Concurrent operative soft tissue procedures: gastrocnemius recession (749), tendo-Achilles lengthening (13), and a combination of the two (1). Concomitant fusions: isolated 1- 2 intermetatarsal arthrodesis (799) and combined with 1-2 intercuneiform arthrodesis (695). Clinical follow-up ranged from three to 186 months, averaging 34 (2 years, ten months). Presently, radiographic assessment has been performed for 154 of the 899 patients included in this study. Of these, 11 had developed adjacent joint arthritis at last radiographic follow-up (7.1%); two with naviculocuneiform arthritis, eight with talonavicular arthritis, and one with both. Conclusion: Based on preliminary data, a successful fusion of the first TMT joint, as treatment of a forefoot deformity such as HV, does not appear to accelerate the development of arthritis in the adjacent joints.

Patient Reported Outcomes Following Revision Ankle Arthrodesis for Ankle Fusion Non-Union

Category: Ankle Arthritis; Hindfoot Introduction/Purpose: Ankle arthrodesis (AA) has, for many years, been considered the gold standard procedure for the surgical treatment of end stage ankle arthritis. Non-union following AA surgery is a devastating complication which subsequently requires revision surgery. However, data on outcomes including patient reported outcome measures (PROMs) following revision ankle arthrodesis (RAA) after failed AA is lacking. The aim of this study is to assess the outcome of RAA for symptomatic non-union after AA including PROMs. Methods: Prospectively collected data from a multicenter database of ankle arthritis surgery was analyzed. Demographic data and PROMs including Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) health survey were collected at regular intervals. Surgeries were performed by six fellowship-trained foot and ankle surgeons between January 2003 and July 2015. 336 primary AA cases were identified, of which 27 (8%) underwent revision for symptomatic AA non-union. Results: Mean follow-up of 27 AA non-union cases was 5.3 years (2-10). There were 16 (59%) males and 11 (41%) females, with a mean age of 62 years (44 - 81) and a mean BMI of 32 (26.5 – 45), respectively. At index AA, 12 (44%) cases were performed arthroscopically. Twenty-three (84%) AA non-union patients were actively smoking pre- and post-operatively, and 15 (56%) were diabetic. Overall union-rate following RAA was 85% (23/27). For RAA the pre-operative mean AOS score of 64.9 (38.8-81.5) improved to 49.1 (24.1-73) at latest follow-up. SF-36 PCS score improved from 27.2 (21.3 – 38.3) to 33.3 (19.1-54.2) and SF-36 MCS score improved from 41.2 (17.5-60.9) to 46.2 (29.3-65.9). Overall complication rate of RAA was 22%, with a re-operation rate of 15%. Conclusion: Revision ankle arthrodesis (RAA) for ankle fusion non-union resulted in a successful fusion of the ankle in 85% of patients with modest improvement in AOS and SF-36 scores. Indeed, even after successful RAA, patients report pain and disability levels comparable to that reported by primary AA patients pre-operatively. Additionally, complication and re-operation rates of RAA are high. This data emphasizes on the importance of achieving a primary fusion in AA. The presented patient reported outcomes may help the treating surgeon to counsel patients prior to RAA surgery to better set their expectations.

αB-Crystallin Peptide Fused with Elastin-like Polypeptide: Intracellular Activity in Retinal Pigment Epithelial Cells Challenged with Oxidative Stress.

Oxidative stress-induced retinal degeneration is among the main contributing factors of serious ocular pathologies that can lead to irreversible blindness. αB-crystallin (cry) is an abundant component of the visual pathway in the vitreous humor, which modulates protein and cellular homeostasis. Within this protein exists a 20 amino acid fragment (mini-cry) with both chaperone and antiapoptotic activity. This study fuses this mini-cry peptide to two temperature-sensitive elastin-like polypeptides (ELP) with the goal of prolonging its activity in the retina. The biophysical properties and chaperone activity of cry-ELPs were confirmed by mass spectrometry, cloud-point determination, and dynamic light scattering 'DLS'. For the first time, this work compares a simpler ELP architecture, cry-V96, with a previously reported ELP diblock copolymer, cry-SI. Their relative mechanisms of cellular uptake and antiapoptotic potential were tested using retinal pigment epithelial cells (ARPE-19). Oxidative stress was induced with H2O2 and comparative internalization of both cry-ELPs was made using 2D and 3D culture models. We also explored the role of lysosomal membrane permeabilization by confocal microscopy. The results indicated successful ELP fusion, cellular association with both 2D and 3D cultures, which were enhanced by oxidative stress. Both constructs suppressed apoptotic signaling (cleaved caspase-3); however, cry-V96 exhibited greater lysosomal escape. ELP architecture is a critical factor to optimize delivery of therapeutic peptides, such as the anti-apoptotic mini-cry peptide; furthermore, the protection of mini-cry via ELPs is enhanced by lysosomal membrane permeabilization.

Iliac crest bone graft versus cell-based grafts to augment spinal fusion: a systematic review and meta-analysis.

Despite successful fusion rates with iliac crest bone graft (ICBG), donor-site morbidity and increased operating time remain a considerable limitation and drive the search for alternatives. In this systematic review, grafts with additional cellular supplementation were compared with ICBG for spinal arthrodesis. We compared safety, efficacy and long-term outcomes, thus providing the current and relevant evidence for orthopaedic surgeons to make informed choices regarding this rapidly developing field. An electronic literature search was conducted according to the PRISMA guidelines by two independent reviewers for articles published up to 1st March 2023 using PubMed, EMBASE and the Cochrane Central Register of Controlled Trial. Cellular allografts were not included. The following data were extracted: Number of patients, type of graft, fusion assessment method, follow-up duration, fusion rates, clinical outcomes and complications. The methodological quality of evidence (MQOE) was assessed using the Risk of Bias 2 (RoB-2) tool and Risk of Bias In Non-Randomised Studies (ROBINS) tool developed by Cochrane for evaluating bias in randomised and non-randomised studies. Ten studies fulfiled the inclusion criteria, including 465 patients. The mean number of patients per study was 43.8 (std dev. 28.81, range 12-100). Two studies demonstrated cell-based therapy to be significantly more successful in terms of fusion rates compared to ICBG. However, the remaining eight demonstrated equivocal results. No study found that cell-based therapy was inferior. No difference was seen between the two groups in three studies who focused on degenerative cohorts. No difference in functional outcome scores was seen between the groups. A number of different preparation techniques for cell-based grafts were used throughout the studies. Cell-based therapy offers a promising alternative to ICBG in spinal fusion surgery, which could help reduce the associated morbidity to patients. This review found that cell-based therapy is non-inferior to iliac crest bone graft and may offer patients an alternative treatment option with fewer complications and reduced post-operative pain. However, the literature to date is limited by heterogeneity of the cell preparation and grafting process. Future research with a unified approach to the cell preparation process is required to fully delineate the potential advantages of this technology.

Application of Escherichia coli-Derived Recombinant Human Bone Morphogenic Protein-2 to Unstable Spinal Fractures.

(1) Background: Recently, Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E. coli-derived rhBMP-2) has been increasingly applied to different types of spinal surgeries and reported to achieve successful fusion. This pilot study aimed to evaluate the clinical efficacy and safety of rhBMP-2 in patients undergoing posterior instrumented fusions for unstable spinal fractures. (2) Methods: This study included ten consecutive patients undergoing spinal surgery using E. coli-derived rhBMP-2 with more than one year of follow-up. Radiologic outcomes were compared, including the average fracture healing period, local kyphosis correction, and clinical outcomes between preoperative and the last follow-up. (3) Results: The average time of radiographic union was 99.9 ± 45.4 (62-192) days, with an average use of 5.2 ± 3.9 months of anabolic agents. Radiologic parameters such as anterior vertebral height and vertebral wedge angle were significantly corrected postoperatively and at the last follow-up. Clinical outcomes other than leg pain were significantly improved after the surgery. In addition, four patients with preoperative neurologic deficits showed improved neurologic status. (4) Conclusions: Combined with the anabolic agents, applying E. coli-derived rhBMP-2 to the fractured vertebral body could be an effective surgical treatment for unstable spinal fractures. Further trials are needed to validate this result.

THE INFLUENCE OF EUROPEAN ART ON CHINESE OPERA CULTURE

The article examines the influence of European culture on the origin and development of Beijing opera, focusing on the penetration and assimilation of European opera's characteristic features into Chinese musical culture. It systematically analyzes these innovations within the historical context, elucidating their role and position in the broader Chinese cultural and historical processes. The study reveals that the primary avenue for introducing European musical canons was through school songs, which, due to their simple composition and ease of performance, served as the basis for incorporating structured European approaches into Chinese music. It notes that the creation of the first officially recognized Chinese opera, “Grey-hair Girl”, followed the emergence of Children's Operas, which exhibited elements of Europeanization while retaining their melodic structure. The conclusions highlight that the development of the European experience within the opera genre unfolded in tandem with the evolution of compositional and dramatic patterns derived from Western opera. However, on a musical and stylistic level, Chinese composers remained rooted in the national tradition, endeavoring to achieve varying degrees of successful fusion between Western form and national content. It was only towards the latter part of the 20th century that a harmonious symbiosis began to emerge, integrating the organizational aspects of opera from the European experience with Chinese identity at different levels.

Blockchain based trusted execution environment architecture analysis for multi - source data fusion scenario

Multi-source data fusion techniques are widely applied in dynamic target detection scenarios, such as target situational awareness, radar signal resolution, and feature fusion labeling. Currently, techniques including clustering, neural networks, Bayesian analysis, and machine learning have been applied to improve the success rate of multi-source data fusion in terms of interference data noise reduction. The research on data tampering prevention of multiple data sources is mainly based on the data distributed authentication technology. The research on performing data fusion process in a trusted execution environment is mainly based on cryptography and codec technology. This paper focuses on the technical application architecture that can effectively improve the comprehensive efficiency of multi-source data fusion processing under the constraints of business scenarios. Accordingly, this paper proposes a trusted execution environment architecture based on blockchain technology for multi-source data fusion scenarios. It integrates the strategy of trusted data source data verification in blockchain smart contracts into the typical multi-source data fusion application architecture. After comparison tests in a simulation environment, the trusted execution environment architecture based on blockchain technology has shown considerable improvements in fusion success rate with limited performance cost.

In Vitro Roles of Burkholderia Intracellular Motility A (BimA) in Infection of Human Neuroblastoma Cell Line.

The bacterial pathogen Burkholderia pseudomallei causes human melioidosis, which can infect the brain, leading to encephalitis and brain abscesses. Infection of the nervous system is a rare condition but is associated with an increased risk of mortality. Burkholderia intracellular motility A (BimA) was reported to play an important role in the invasion and infection of the central nervous system in a mouse model. Thus, to gain insight of the cellular mechanisms underlying the pathogenesis of neurological melioidosis, we explored the human neuronal proteomics to identify the host factors that are up- and downregulated during Burkholderia infection. When infected the SH-SY5Y cells with B. pseudomallei K96243 wild-type (WT), 194 host proteins showed a fold change of >2 compared with uninfected cells. Moreover, 123 proteins showed a fold change of >2 when infected with a knockout bimA mutant (ΔbimA) mutant compared with WT. The differentially expressed proteins were mainly associated with metabolic pathways and pathways linked to human diseases. Importantly, we observed the downregulation of proteins in the apoptosis and cytotoxicity pathway, and in vitro investigation with the ΔbimA mutant revealed the association of BimA with the induction of these pathways. Additionally, we disclosed that BimA was not required for invasion into the neuron cell line but was necessary for effective intracellular replication and multinucleated giant cell (MNGC) formation. These findings show the extraordinary capacity of B. pseudomallei in subverting and interfering with host cellular systems to establish infection and extend our understanding of B. pseudomallei BimA involvement in the pathogenesis of neurological melioidosis. IMPORTANCE Neurological melioidosis, caused by Burkholderia pseudomallei, can result in severe neurological damage and enhance the mortality rate of melioidosis patients. We investigate the involvement of the virulent factor BimA, which mediates actin-based motility, in the intracellular infection of neuroblastoma SH-SY5Y cells. Using proteomics-based analysis, we provide a list of host factors exploited by B. pseudomallei. The expression level of selected downregulated proteins in neuron cells infected with the ΔbimA mutant was determined by quantitative reverse transcription-PCR and was consistent with our proteomic data. The role of BimA in the apoptosis and cytotoxicity of SH-SY5Y cells infected by B. pseudomallei was uncovered in this study. Additionally, our research demonstrates that BimA is required for successful intracellular survival and cell fusion upon infection of neuron cells. Our findings have significant implications for understanding the pathogenesis of B. pseudomallei infections and developing novel therapeutic strategies to combat this deadly disease.

Sclerostin small-molecule inhibitors promote osteogenesis by activating canonical Wnt and BMP pathways.

The clinical healing environment after a posterior spinal arthrodesis surgery is one of the most clinically challenging bone-healing environments across all orthopedic interventions due to the absence of a contained space and the need to form de novo bone. Our group has previously reported that sclerostin in expressed locally at high levels throughout a developing spinal fusion. However, the role of sclerostin in controlling bone fusion remains to be established. We computationally identified two FDA-approved drugs, as well as a single novel small-molecule drug, for their ability to disrupt the interaction between sclerostin and its receptor, LRP5/6. The drugs were tested in several in vitro biochemical assays using murine MC3T3 and MSCs, assessing their ability to (1) enhance canonical Wnt signaling, (2) promote the accumulation of the active (non-phosphorylated) form of β-catenin, and (3) enhance the intensity and signaling duration of BMP signaling. These drugs were then tested subcutaneously in rats as standalone osteoinductive agents on plain collagen sponges. Finally, the top drug candidates (called VA1 and C07) were tested in a rabbit posterolateral spine fusion model for their ability to achieve a successful fusion at 6 wk. We show that by controlling GSK3b phosphorylation our three small-molecule inhibitors (SMIs) simultaneously enhance canonical Wnt signaling and potentiate canonical BMP signaling intensity and duration. We also demonstrate that the SMIs produce dose-dependent ectopic mineralization in vivo in rats as well as significantly increase posterolateral spine fusion rates in rabbits in vivo, both as standalone osteogenic drugs and in combination with autologous iliac crest bone graft. Few if any osteogenic small molecules possess the osteoinductive potency of BMP itself - that is, the ability to form de novo ectopic bone as a standalone agent. Herein, we describe two such SMIs that have this unique ability and were shown to induce de novo bone in a stringent in vivo environment. These SMIs may have the potential to be used in novel, cost-effective bone graft substitutes for either achieving spinal fusion or in the healing of critical-sized fracture defects. This work was supported by a Veteran Affairs Career Development Award (IK2-BX003845).

Risk Factors of Nonfusion after Anterior Cervical Decompression and Fusion in the Early Postoperative Period: A Retrospective Study.

Although high fusion rates have been reported for anterior cervical decompression and fusion (ACDF) in the medium and long term, the risk of nonfusion in the early period after ACDF remains substantial. This study investigates early risk factors for cage nonfusion in patients undergoing single- or multi-level ACDF. This was a retrospective study. From August 2020 to December 2021, 107 patients with ACDF, including 197 segments, were enrolled, with a follow-up of 3 months. Among the 197 segments, 155 were diagnosed with nonfusion (Nonfusion group), and 42 were diagnosed with fusion (Fusion group) in the early period after ACDF. We assessed the significance of the patient-specific factors, radiographic indicators, serum factors, and clinical outcomes. The Wilcoxon rank sum test, t-tests, analysis of variance, and stepwise multivariate logistic regression were used for statistical analysis. Univariate analysis showed that smoking, insufficient improvement in the C2-7 Cobb angle (p = 0.024) and the functional spinal unit Cobb angle (p = 0.022) between preoperative and postoperative stages and lower serum calcium (fusion: 2.34 ± 0.12 mmol/L; nonfusion: 2.28 ± 0.17 mmol/L, p = 0.003) β-carboxyterminal telopeptide end of type 1 collagen (β-CTX) (fusion: 0.51 [0.38, 0.71]; nonfusion: 0.43 [0.31, 0.57], p = 0.008), and N-terminal fragment of osteocalcin (N-MID-BGP) (fusion: 18.30 [12.15, 22.60]; nonfusion: 14.45 [11.65, 18.60], p = 0.023) are risk factors for nonfusion in the early period after ACDF. Stepwise logistic regression analysis revealed that poor C2-7 Cobb angle improvement (odds ratio [OR], 1.107 [1.019-1.204], p = 0.017) and lower serum calcium (OR, 3.700 [1.138-12.032], p = 0.030) are risk factors. Patients with successful fusion after ACDF had higher preoperative serum calcium and improved C2-7 Cobb angle than nonfusion patients at 3 months. These findings suggest that serum calcium could be used to identify patients at risk of nonfusion following ACDF and that correcting the C2-7 Cobb angle during surgery could potentially increase fusion in the early period after ACDF.

Unilateral Minimally Invasive Across-Midline Vertebral Column Resection Partially Corrects Thoracolumbar Kyphosis – A Case Series

The goal of this study was to describe the indirect and partial correction of spine kyphotic deformities (secondary to various pathologies) achieved by minimally invasive posterolateral extracavitary approach (MIS-PLECA) for corpectomy. The authors retrospectively reviewed a consecutive case series of 12 patients undergoing MIS PLECA in a single institution. Perioperative data were collected and follow-up CTs and radiographs were reviewed to assess for interbody arthrodesis. The mean age was 60.7 ± 20.8 years (58.4% males). The etiologies of deformity included pathological fracture (41.6%), acute trauma (30%), and infection. An expandable cage was used in 66.7% of patients for anterior reconstruction. The mean total EBL was 764.1 ± 332.9 ml. The mean operative time was 413.3 ± 98.8 min. The average length of hospital stay was 5.8 ± 2.5 days. A consistent degree of focal correction of sagittal alignment was seen in all patients with a mean correction of sagittal angle of 7.4 ± 4.3 degrees (P<.0001). The mean duration of rehabilitation was 8.5 ± 6.7 days. All patients remained neurologically stable at the last follow-up with a mean follow-up period of 20.1 ± 12.8 months. Successful fusion was achieved in 91.7% at the last follow-up. MIS PLECA for corpectomy appears to be a feasible, safe, and effective MIS technique for select patients, particularly those who cannot tolerate the traditional open approach. Additionally, a focal sagittal deformity correction can be achieved using MIS corpectomy.

Three-Dimensional-Printed Titanium Versus Polyetheretherketone Cages for Lumbar Interbody Fusion: A Systematic Review of Comparative In Vitro, Animal, and Human Studies.

Interbody fusion is a workhorse technique in lumbar spine surgery that facilities indirect decompression, sagittal plane realignment, and successful bony fusion. The 2 most commonly employed cage materials are titanium (Ti) alloy and polyetheretherketone (PEEK). While Ti alloy implants have superior osteoinductive properties they more poorly match the biomechanical properties of cancellous bones. Newly developed 3-dimensional (3D)-printed porous titanium (3D-pTi) address this disadvantage and are proposed as a new standard for lumbar interbody fusion (LIF) devices. In the present study, the literature directly comparing 3D-pTi and PEEK interbody devices is systematically reviewed with a focus on fusion outcomes and subsidence rates reported in the in vitro, animal, and human literature. A systematic review directly comparing outcomes of PEEK and 3D-pTi interbody spinal cages was performed. PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Mean Newcastle-Ottawa Scale score for cohort studies was 6.4. A total of 7 eligible studies were included, comprising a combination of clinical series, ovine animal data, and in vitro biomechanical studies. There was a total population of 299 human and 59 ovine subjects, with 134 human (44.8%) and 38 (64.4%) ovine models implanted with 3D-pTi cages. Of the 7 studies, 6 reported overall outcomes in favor of 3D-pTi compared to PEEK, including subsidence and osseointegration, while 1 study reported neutral outcomes for device related revision and reoperation rate. Though limited data are available, the current literature supports 3D-pTi interbodies as offering superior fusion outcomes relative to PEEK interbodies for LIF without increasing subsidence or reoperation risk. Histologic evidence suggests 3D-Ti to have superior osteoinductive properties that may underlie these superior outcomes, but additional clinical investigation is merited.

Delayed myelopathy after remote C1-2 sublaminar wire fixation: illustrative case.

Atlantoaxial sublaminar wiring complications, both early and delayed, have been documented. However, delayed neurological compromise 27 years after successful fusion is a rare but possible occurrence. A 76-year-old male, who had undergone C1-2 sublaminar wire fusion for atlantoaxial instability in 1995, presented with symptoms of progressive right arm weakness, falls, and incontinence of bowel and bladder over a 1-week period. Initial imaging workup revealed bowing of the C1-2 sublaminar wires resulting in cervical spinal cord compression and T2-weighted signal changes. A C1-2 laminectomy was performed to remove the wires and decompress the spinal cord with improvement in the patient's neurological status. This rare case highlights the potential for delayed cervical myelopathy and cord compression from sublaminar wires, even after a successful fusion. In patients with a history of sublaminar wiring who experience new neurological deficits, it is essential to evaluate the hardware for migration.

MSAFNet: Multiscale Successive Attention Fusion Network for Water Body Extraction of Remote Sensing Images

Water body extraction is a typical task in the semantic segmentation of remote sensing images (RSIs). Deep convolutional neural networks (DCNNs) outperform traditional methods in mining visual features; however, due to the inherent convolutional mechanism of the network, spatial details and abstract semantic representations at different levels are difficult to capture accurately at the same time, and then the extraction results decline to become suboptimal, especially on narrow areas and boundaries. To address the above-mentioned problem, a multiscale successive attention fusion network, named MSAFNet, is proposed to efficiently aggregate the multiscale features from two aspects. A successive attention fusion module (SAFM) is first devised to extract multiscale and fine-grained features of water bodies, while a joint attention module (JAM) is proposed to further mine salient semantic information by jointly modeling contextual dependencies. Furthermore, the multi-level features extracted by the above-mentioned modules are aggregated by a feature fusion module (FFM) so that the edges of water bodies are well mapped, directly improving the segmentation of various water bodies. Extensive experiments were conducted on the Qinghai-Tibet Plateau Lake (QTPL) and the Land-cOVEr Domain Adaptive semantic segmentation (LoveDA) datasets. Numerically, MSAFNet reached the highest accuracy on both QTPL and LoveDA datasets, including Kappa, MIoU, FWIoU, F1, and OA, outperforming several mainstream methods. Regarding the QTPL dataset, MSAFNet peaked at 99.14% and 98.97% in terms of F1 and OA. Although the LoveDA dataset is more challenging, MSAFNet retained the best performance, with F1 and OA being 97.69% and 95.87%. Additionally, visual inspections exhibited consistency with numerical evaluations.

Delayed successful interbody fusion after initially failed midline lumbar interbody fusion spinal arthrodesis in a patient with degenerative lumbar spondylolisthesis and severe osteoporosis.

Introduction. Dual x-ray absorptiometry (DEXA) scan has been the gold standard for assessing bone mineral density prior to spinal instrumentation surgery. DEXA scans, on the other hand, can produce falsely elevated measurements in patients with severe degenerative changes, compression fractures, and aortic calcification, which can lead to incorrect patient selection and failed interbody fusion. Materials and methods. Detailed anamnesis of disease development, thorough clinical examination, patient-reported outcome measures (pain VAS, ODI, SF-12), preoperative and postoperative bone-window CT of the spine (interbody fusion status assessment), vertebral bone mineral density assessment by DEXA scan, vertebral bone density measurement in Hounsfield units by computer tomography, and the review of published literature were analysed. Results. A 67-year-old woman was diagnosed with L4-L5 degenerative spondylolisthesis. DEXA scan revealed normal bone mineral density in the lumbar vertebrae. The patient underwent midline lumbar interbody fusion (MIDLIF). The postoperative course was complicated by the occurrence of clinical and radiographic signs of pseudarthrosis. She refused revision surgery and was lost to follow-up. Three years postoperatively, she presented in good physical condition, with significant improvement in pain and functional disability. A CT scan showed delayed successful interbody fusion with complete resolution of radiolucency around implants. Conclusions. This case report summarizes some of the possible errors in diagnosis and surgical treatment in patients with degenerative pathology associated with severe vertebral osteoporosis.