ObjectiveTo assess the mid-long-term clinical and radiological outcomes of zero-profile (ZP) compared with stand-alone (ST) cages for two-level anterior cervical discectomy and fusion (ACDF).MethodsWe included 77 patients (39 women and 38 men) who underwent two-level ACDF between May 5, 2016, and May 5, 2020, and who were followed up for at least 1 year. The subjects were divided into the ST (n = 38) and ZP (n = 39) group. For the evaluation of functional status, Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) scores were used. Additionally, radiological outcomes and procedure complications were observed at final follow-up.ResultsBoth groups had excellent clinical outcomes at the final follow-up. There were no significant intergroup (ZP vs. ST) differences in the fusion rate (91.02% vs. 90.79%, P > 0.05) and postoperative dysphagia (15.4% vs. 2.6%, P = 0.108). However, the disc height at the final follow-up in the ZP group was higher than that in the ST group (6.86 ± 0.84 vs. 6.17 ± 1.03, P = 0.002). The ZP group accomplished a lower loss of cervical lordosis (18.46 ± 4.78 vs. 16.55 ± 4.36, P = 0.071), but without reaching statistical significance.ConclusionACDF with either ZP or ST cages turns out to be a dependable strategy for two-level ACDF in terms of clinical results. However, compared with the ST, the ZP cage may achieve a significantly lower loss of disc height.

Objective: Hydrogen sulfide (H 2 S) has been found to act as an important gasotransmitter to regulate cell activities. This study aimed to investigate the effect of H 2 S on autophagy of nucleus pulposus (NP) cells under hypoxia and possible mechanism.Materials and Methods: NP cells were isolated from rat caudal discs. Cobalt chloride was used to mimic hypoxia, sodium hydrosulfide was used to emulate exogenous H 2 S and 3-methyladenine was used to block cell autophagy. Cell viability was assessed by phase contrast microscope and Cell Counting Kit-8 method. Moreover, expression of key autophagic proteins was analyzed via western blotting, and transmission electron microscopy was performed to detect autophagosomes.Results: Hypoxia markedly impaired NP cell proliferation compared with control.Whereas H 2 S provided pro-proliferation and pro-autophagy effects on hypoxic NP cells. However, these beneficial impact of H 2 S on hypoxic NP cells were reversed by autophagy inhibitor.Conclusions: Our results showed that H 2 S played a cytoprotective role in NP cells exposed to hypoxia in an autophagy-dependent manner.

BACKGROUND Deep venous thrombosis (DVT) is a serious complication of lumbar spine surgery. Current guidelines recommend pharmacomechanical prophylaxis for patients at high risk of DVT after spine surgery. May-Thurner syndrome (MTS), a venous anatomical variation that may require invasive intervention, is an often overlooked cause of DVT. To date, no case reports of symptomatic MTS caused by isthmic spondylolisthesis or subsequent acute DVT after posterior lumbar surgery have been published. CASE SUMMARY We here present a case of a patient who developed acute DVT 4 h after spondylolisthesis surgery, and MTS was only considered after surgery, during a review of a gynecological enhanced computed tomography image taken before the procedure. CONCLUSION In conclusion, clinicians should consider MTS in the presence of a dangerous triad: spondylolisthesis, elevated D-dimer levels, and sonographically indicated unilateral deep vein dilation. Consultation with a vascular surgeon is also essential to MTS management.

Purpose To evaluate the effect of cement augmentation of cortical bone trajectory (CBT) screws using a novel calcium phosphate–based nanocomposite (CPN). Material and Methods CBT screws were placed into cadaveric lumbar vertebrae. Depending on the material used for augmentation, they were divided into the following three groups: CPN, polymethylmethacrylate (PMMA), and control. Radiological imaging was used to evaluate the cement dispersion. Biomechanical tests were conducted to measure the stability of CBT screws. A rat cranial defect model was used to evaluate biodegradation and osseointegration of the CPN. Results After cement augmentation, the CPN tended to disperse into the distal part of the screws, whereas PMMA remained limited to the proximal part of the screws (P < 0.05). As for cement morphology, the CPN tended to form a concentrated mass, whereas PMMA arranged itself as a scattered cement cloud, but the difference was not significant (P > 0.05). The axial pullout test showed that the average maximal pullout force (Fmax) of CPN-augmented CBT screws was similar to that of the PMMA group (CPN, 1639.56 ± 358.21 N vs PMMA, 1778.45 ± 399.83 N; P = 0.745) and was significantly greater than that of the control group (1019.01 ± 371.98 N; P < 0.05). The average torque value in the CPN group was higher than that in the control group (CPN, 1.51 ± 0.78 N∙m vs control, 0.97 ± 0.58 N∙m) and lower than that in the PMMA group (1.93 ± 0.81 N∙m), but there were no statistically significant differences (P > 0.05). The CPN could be biodegraded and gradually replaced by newly formed bone tissue after 12 weeks in a rat cranial defect model. Conclusion The biocompatible CPN could be a valuable augmentation material to enhance CBT screw stability.