Objective: Cervical hybrid surgery optimizes the use of cervical disc arthroplasty (CDA) and zero-profile (ZOP) devices in anterior cervical discectomy and fusion (ACDF) but lacks uniform combination and biomechanical standards, especially in revision surgery (RS). This study aimed to investigate the biomechanical characteristics of adjacent segments of the different hybrid RS constructs in ACDF RS.Methods: An intact 3-dimensional finite element model generated a normal cervical spine (C2–T1). This model was modified to the primary C5–6 ACDF model. Three RS models were created to treat C4–5 adjacent segment degeneration through implanting cages plus plates (Cage-Cage), ZOP devices (ZOP-Cage), or Bryan discs (CDA-Cage). A 1.0-Nm moment was applied to the primary C5–6 ACDF model to generate total C2–T1 range of motions (ROMs). Subsequently, a displacement load was applied to all RS models to match the total C2–T1 ROMs of the primary ACDF model.Results: The ZOP-Cage model showed lower biomechanical responses including ROM, intradiscal pressure, maximum von Mises stress in discs, and facet joint force in adjacent segments compared to the Cage-Cage model. The CDA-Cage model exhibited the lowest biomechanical responses and ROM ratio at adjacent segments among all RS models, closely approached or lower than those in the primary ACDF model in most motion directions. Additionally, the maximum von Mises stress on the C3–4 and C6–7 discs increased in the Cage-Cage and ZOP-Cage models but decreased in the CDA-Cage model when compared to the primary ACDF model.Conclusion: The CDA-Cage construct had the lowest biomechanical responses with minimal kinematic change of adjacent segments. ZOP-Cage is the next best choice, especially if CDA is not suitable. This study provides a biomechanical reference for clinical hybrid RS decision-making to reduce the risk of ASD recurrence.

A healthy cervical spine with normal movement is the basis of many daily activities and is essential for maintaining a good quality of life. However, the alignment, fusion, and structure of the cervical spine can change for various reasons, leading to cervical deformity, mainly kyphosis. Approximately 5%‒20% of spinal infections in the cervical spine cause cervical deformity. The deformity can recover early; however, the disease's long-term existence or the continuous action of abnormal stress may lead to intervertebral fusion and abnormal osteophytes. Many gaps and controversies exist regarding infectious cervical deformities, including a lack of clear definitions and an acceptable classification system thereby requiring further research. Moreover, there is no consensus on the indications for postinfectious cervical deformity associated with Mycobacterium tuberculosis, Staphylococcus aureus, and Brucellosis. Therefore, we reviewed and discussed the incidence, clinical manifestations, changes, and treatment of infectious and inflammatory secondary cervical deformities from common to rare to provide a theoretical basis for clinical decision-making.

Background: Hybrid surgery (HS) combined cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion (ACDF) is emerging, but its biomechanical effects as a revision surgery (RS) on adjacent segments were unclear.Objectives: This finite element (FE) study aimed to investigate the biomechanical characteristics of HS to treat two‐level discontinuous ASD in ACDF RS.Methods: A C2‐T1 intact FE model was established and modified to a primary C5/6 ACDF model and five RS models. These RS models' segments C4/5 and C6/7 were revised using cage plus plate (C), zero‐profile devices (P), and Bryan disc (D), respectively, generating C‐C‐C, P‐C‐P, D‐C‐P, P‐C‐D, and D‐C‐D models. In the intact and C5/6 ACDF models, a 1.0 Nm moment was used to produce the range of motion (ROM). A displacement load was applied to all RS models, to achieve a total ROM match that of the primary C5/6 ACDF model.Results: In the P‐C‐P model, biomechanical responses including ROM, Intradiscal pressure (IDP), Facet joint force (FJF), and Maximum von Mises stresses of discs at segments C3/4 and C7/T1 were slightly lower than the C‐C‐C model. The biomechanical response parameters at segments C3/4 and C7/T1 of P‐C‐D, D‐C‐P, and D‐C‐D were smaller than those in C‐C‐C and P‐C‐P models. D‐C‐D had the most significant effect on reducing all biomechanical responses among all RS models in segments C3/4 and C7/T1. Moreover, the disc stress cloud maps showed that the maximum von Mises stress of the C3/4 disc was higher than that of C7/T1.Conclusions: D‐C‐D, P‐C‐D, and D‐C‐P are good RS choices for reducing the biomechanical responses, and D‐C‐D was the best choice. P‐C‐P can be the best recommendation when it does not meet the CDA indications. This study provided a biomechanical reference for hybrid surgical decision‐making in the ACDF RS for preventing ASD recurrence.

Background:Distractive spinal cord injury (DSCI), a severe complication of spinal deformity correction surgery, is characterized by rapid neuronal loss. However, the molecular mechanisms linking mechanical distraction to apoptosis remain unclear. Here, we tested whether sodium rutin (NaR), a water-soluble rutin derivative with improved oral bioavailability, mitigates DSCI.Methods:We employed an in vivo rat DSCI model and an in vitro mechanical distraction (DIS) model using neuronal cells. The therapeutic efficacy of NaR was evaluated using locomotor function assessments (Basso–Beattie–Bresnahan score and footprint analysis), histopathology, and transmission electron microscopy. Molecular docking simulations were performed to predict the binding affinity of NaR to Erb-B2 receptor tyrosine kinase 4 (ErbB4). Mechanistic investigations targeting the ErbB4/protein kinase B (Akt) axis, reactive oxygen species (ROS), and apoptotic pathways were conducted using western blot analysis and immunofluorescence.Results:DIS suppressed ErbB4 phosphorylation and downstream Akt signaling, accompanied by the activation of B-cell lymphoma 2/Bcl-2-associated X protein/Caspase-3 (Bcl-2/Bax/Caspase-3) apoptotic pathways after DSCI. Simultaneously, DIS induced a decrease in the mitochondrial membrane potential (ΔΨm) and accumulation of mitochondrial ROS, along with a significant reduction in superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4) levels. NaR treatment engaged ErbB4 to restore ErbB4/Akt signaling, inhibited mitochondrial ROS signaling, ameliorated ΔΨm, and reduced the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic neurons, thereby inhibiting neuronal apoptosis. However, the inhibition of ErbB4 phosphorylation along with NaR treatment significantly reversed these therapeutic effects. Furthermore, the pharmacological administration of NaR ameliorated histopathological and neuronal ultrastructural damage in the spinal cord tissues, increased the number of surviving neurons, and facilitated locomotor recovery after DSCI.Conclusions:These findings identify ErbB4 and ROS signaling as key regulators of neuronal survival during DSCI and establish NaR as a candidate therapeutic strategy for DSCI associated with spinal deformity correction surgery.

INPLASY202430047 Comparison of Hybrid Surgery and Two-Level ACDF in Treating Consecutive Cervical Degenerative Disc Disease: A Systematic Review and Meta-Analysis Keywords: Cervical degenerative di…