Reactive oxygen species (ROS) are thought to have a strong correlation with a number of intervertebral disc (IVD) diseases. Here, we aimed to determine whether ROS represent an etiology of low back pain (LBP) during IVD degeneration. Thirty degenerated intervertebral disc samples were obtained from patients, and ROS levels were quantified using dihydroethidium (DHE) staining. The results suggested a significant correlation between the ROS level and the severity of LBP. Subsequently, a puncture‐induced LBP model was established in rats, and ROS levels significantly increased compared with those in the sham surgery group, accompanied with severe puncture‐induced IVD degeneration. In addition, when ROS levels were increased by H₂O₂ administration or decreased by NAC treatment, the rats showed increased or decreased LBP, respectively. Based on this evidence, we further determined that stimulation with H₂O₂ in nucleus pulposus cells (NPCs) in vivo or in vitro resulted in upregulation of substance P (SP), a peptide thought to be involved in the synaptic transmission of pain, and that the severity of LBP decreased when SP levels were increased by exogenous SP administration or neutralized via aprepitant treatment in the IVDs of rats. In conclusion, ROS are primary inducers of LBP based on clinical and animal data, and the mechanism involves ROS stimulation of NPCs to secrete SP, which is a critical neurotransmitter peptide, to promote LBP in IVDs. Therefore, reducing the level of ROS with specific drugs and inhibiting SP may be alternative methods to treat LBP in the clinic.

Intervertebral disc degeneration (IDD) is a chronic disease affecting millions of patients; however, its specific etiology is unknown. G protein‐coupled receptors (GPRs) are a superfamily of integral membrane receptors in cells, and the receptors respond to a diverse range of stimuli and participate in multiple cellular activities. Here, using RNA‐sequencing (RNA‐seq) methods and immunohistochemistry, we revealed that G protein‐coupled receptor 35 (GPR35) may have a relationship with IDD. Then, we demonstrated that the deletion of GPR35 in nucleus pulposus cells (NPCs) with siRNA or in Gpr35^-/- mice significantly alleviated IDD caused by senescence or mechanical stress, further validating the pathological role of GPR35 in IDD. In addition, GPR35 induced the influx of Ca²⁺ and upregulation of reactive oxygen species (ROS) under mechanical stress in NPCs, which we believe to be the mechanism of GPR35‐induced IDD. Finally, GPR35 caused upregulation of ROS in NPCs under mechanical stress, while excessive ROS stimulated the NPCs to express more GPR35 with a significant dose or time response. The u‐regulated GPR35 could sense mechanical stress to produce more ROS and perpetuate this harmful cycle. In summary, our study shows that GPR35 plays a critical role in mediating IDD via mediating the influx of calcium ions and upregulating ROS, which implies a strong potential advantage of GPR35 as a prevention and treatment target in IDD.

Polyetheretherketone (PEEK) is an important material applied in orthopedic applications, as it posses favorable properties for orthopedic implants, e.g., radiolucency and suitable elastic modulus. However, PEEK exhibits insufficient osteogenesis and osteointegration that limits its clinical applications. In this study, we aimed to enhance the osteogenisis of PEEK by using a surface coating approach. Nanocomposite coating composed of albumin/lithium containing bioactive glass nanospheres was fabricated on PEEK through dip-coating method. The presence of nanocomposite coating on PEEK was confirmed by SEM, FTIR, and XRD techniques. Nanocomposite coatings significantly enhanced hydrophilicity and roughness of PEEK. The nanocomposite coatings also enhanced adhesion, proliferation, and osteogenic differentiation of bone mesenchymal stem cells due to the presence of bioactive glass nanospheres and the BSA substrate film. The results indicate the great potential of the nanocomposite coating in enhancing osteogenesis and osteointegration of PEEK implants.

To investigate the long-term outcomes of young spondylolysis patients treated with smiley face rod surgery. The study is a retrospective analysis of the clinical data of 45 young lumbar spondylolysis patients from 2008 to 2024. All patients underwent smiley face rod surgery and the follow-up period ranged from 3 months to 17 years. The clinical outcomes (VAS score, ODI index, and Odom score) and radiological evaluations were compared before/after surgery and at the final follow-up. All the participations reported satisfactory short-term outcomes after smiley face rod surgery, with VAS scale and ODI index improved significantly 3 months after surgery. The VAS scale and ODI index both maintained good enough until final follow-up (mean 11.2 years). The successful union rate was only 57.5% at 12 months after surgery and 58.6% at final follow-up, as shown in 3D-CT scan. And the VAS and ODI scales had no statistical difference between the healed and unhealed patients. The smiley face rod technique demonstrated long-term satisfactory outcomes for treating young spondylolysis. Though the healing rate was only 57.5–58.6%, all patients reported excellent clinic outcomes and the healing status had no impact on clinic outcomes.

Purpose: The aim of this study was to explore short-term radiological findings after contiguous two-level ACDF with Zero-P VA devices. Methods: Patients who underwent contiguous two-level anterior cervical discectomy and fusion (ACDF) from C3 to C7 with a Zero-P VA system were followed. Cervical anteroposterior and lateral X-rays and functional outcomes were assessed 3 months after surgery. Results: Overall, 34.9% of patients had prosthesis subsidence and 74.6% screw loosening. Up to 46.8% of the patients with screw loosening also experienced prosthesis subsidence compared with 0 patients without screw loosening (p=0.0005). The screw-loosening rate was 91.7% in patients with poor positioning of the screw/cage and 70.6% in patients without poor positioning of the screw/cage, but no statistical difference was found between the groups (p=0.267). The subsidence rate was 50% in patients with poor positioning of the screw/cage and 31.4% in patients without poor positioning of the screw/cage, but no statistical difference was found between the groups (p=0.314). VAS scores of patients with prosthesis subsidence were much higher than those without (p=0.031), but this difference was not found for patients with or without screw loosening (p=0.116). The NDI scale was much higher in patients regradless of screw loosening or subsidence. Conclusion: Screw loosening and prosthesis subsidence happen frequently after contiguous two-level ACDF with Zero-P VA. Screw loosening seems to be the only risk factor for prosthesis subsidence.