Comparative Analysis of Cage Subsidence in Anterior Cervical Decompression and Fusion: Zero Profile Anchored Spacer (ROI-C) vs. Conventional Cage and Plate Construct.

Background: Anterior cervical discectomy and fusion (ACDF) has been widely performed to treat cervical generative diseases. Cage subsidence is a complication after ACDF. Although it is known that segmental kyphosis, acceleration of adjacent segmental disease, and restenosis may occur due to cages subsidence; however detailed research comparing zero-profile cages (ROI-C) and conventional plate and cage construct (CPC) on cage subsidence has been lacking. Objective: The objectives of this study was to compare the rate of postoperative cage subsidence between zero profile anchored spacer (ROI-C) and conventional cage and plate construct (CPC) and investigate the risk factors associated with cage subsidence following ACDF. Methods: Seventy-four patients with ACDF who received either ROI-C or CPC treatment from October 2013 to August 2018 were included in this retrospective cohort study. Clinical and radiological outcomes and the incidence of cage subsidence at final follow up-were compared between groups. All patients were further categorized into the cage subsidence (CS) and non-cage subsidence (NCS) groups for subgroup analysis. Results: The overall subsidence rate was higher in the ROI-C group than in the CPC group (66.67 vs. 38.46%, P = 0.006). The incidence of cage subsidence was significantly different between groups for multiple-segment surgeries (75 vs. 34.6%, P = 0.003), but not for single-segment surgeries (54.55 vs. 42.30%, P = 0.563). Male sex, operation in multiple segments, using an ROI-C, and over-distraction increased the risk of subsidence. Clinical outcomes and fusion rates were not affected by cage subsidence. Conclusion: ROI-C use resulted in a higher subsidence rate than CPC use in multi-segment ACDF procedures. The male sex, the use of ROI-C, operation in multiple segments, and over-distraction were the most significant factors associated with an increase in the risk of cage subsidence.

Comparison of the Wiltse Approach and Percutaneous Pedicle Screw Fixation Under O-arm Navigation for the Treatment of Thoracolumbar Fractures.

OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of the Wiltse approach and percutaneous pedicle screw placement under O-arm navigation for the treatment of thoracolumbar fracture. METHODS: We enrolled a total of 54 patients with neurologically intact thoracolumbar fracture who received minimally invasive treatments between October 2014 and October 2018 in this retrospective study. Among these, 28 patients (22 males and six females, with a mean age of 48.6 ± 9.6 years) were treated with pedicle screw fixation through the Wiltse approach (WPSF), and another 26 (15 males and 11 females, with a mean age of 45.7 ± 10.6 years) received percutaneous pedicle screw fixation under O-arm navigation (OPSF). Statistical methods were used to perform a detailed comparison of clinical outcomes, radiologic findings, and complications between the two groups obtained preoperatively, postoperatively, and at last follow-up. RESULTS: All patients underwent surgery successfully and finished a follow-up of more than 12 months. No serious complications, such as infection, blood vessel injury, or spinal cord or nerve root injury occurred. Visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, local Cobb angle (LCA), vertebral wedge angle (VWA), and R value were notably improved after surgery, though there was no clear discrepancy between the groups at each time point (P > 0.05). During the follow-up period, no patients developed neurological impairment or implant-related complications, and no patients underwent revision surgery. The WPSF group had a significantly shorter operation time than the OPSF group (68.1 ± 9.8 vs 76.1 ± 9.0 minutes, P = 0.005). Moreover, the WPSF group showed less cost of surgery than the WPSF group (48142.1 ± 1430.1 vs 59035.4 ± 1152.7 CNY, P < 0.001). There were no significant differences between the two groups in terms of the intraoperative bleeding, length of incision, or postoperative hospitalization time (P > 0.05). The accuracy of pedicle screw placement was 95.2% (160/168) in the WPSF group and 96.8% (151/156) in the OPSF group, with no significant difference between the groups (P = 0.432). CONCLUSION: Both WPSF and OPSF were safe and effective for the treatment of thoracolumbar fracture. Although the two groups showed favorable clinical and radiologic outcomes through to final follow-up, we recommended the minimally invasive WPSF given its shorter operation time and lower cost of surgery.

Percutaneous kyphoplasty for a patient of thoracolumbar osteoporotic vertebral compression fractures with distal lumbosacral pain: a case report.

When patients combined thoracolumbar osteoporotic vertebral compression fracture (OVCF) with lumbar degenerative disease, whose main clinical manifestations are distal lumbosacral pain (DLP), the therapeutic schedule should be made cautiously. We reported an 80-year-old female presented with long-term lumbosacral pain accused of lumbar disc herniation. Percutaneous kyphoplasty (PKP) had been received because of OVCF at L1 vertebral body. Twenty days ago, the elderly felt the DLP was aggravated with no obvious reason. Magnetic resonance imaging (MRI) showed the fresh compression fracture of L2 vertebral body, but the palpation found absence of focal tenderness. Then, we chose to perform PKP at L2 vertebral body, and the patient felt substantial pain relief of lumbosacral area after operation. This case showed that patient manifested as DLP that combined thoracolumbar OVCF with lumbar degenerative disease, PKP has a significant relieving effect on lumbosacral pain.

X-ray therapy promotes structural regeneration after spinal cord injury in a rat model.

OBJECTIVE: This study aims to investigate the therapeutic effects and mechanisms of x-ray treatment on rats following spinal cord injury (SCI). METHODS: Forty-six female Sprague-Dawley rats were subjected to spinal cord injury using the modified Allen weight-drop method. The animals were randomly divided into six groups. Two of the animal groups were irradiated with 10 Gy at the lesion site; another two groups were irradiated with 20 Gy; and the last two groups without irradiation were regarded as the sham group. One of the each of two animal groups was euthanized at different time points at 4 and 12 weeks, respectively, after irradiation. Spinal cord calluses were assessed using kinology and electrophysiology and histology methods. RESULTS: In all of the groups, the neurofilament (NF) counts at 14 weeks were found to be higher than that at 6 weeks after SCI. Both 10-Gy irradiated and 20-Gy irradiated groups were higher than those of the sham group at each time point (P < 0.05). The myelin basic protein (MBP) count decreased at 14 weeks after SCI in the irradiated groups (P < 0.05) but increased at 14 weeks in the sham group (P < 0.05). Furthermore, the MBP count of the irradiated groups was lower than that of the sham group at 14 weeks (P < 0.05). The glial fibrillary acidic protein (GFAP) and Nogo-A counts at 14 weeks were higher than those at 6 weeks in all the groups (P < 0.05), and there was no statistical significance with kinology and electrophysiology tests in all groups. CONCLUSIONS: A self-repair mechanism exists after spinal cord injury, which lasts at least 14 weeks. X-ray therapy promotes the regeneration of the spinal cord system after injury.

The application of a zero-profile implant in anterior cervical discectomy and fusion.

We analyzed the clinical efficacy of the Zero-P implant (Synthes GmbH Switzerland, Oberdorf, Switzerland) in the treatment of single level cervical spondylotic myelopathy. The clinical data of 47 patients with single level cervical spondylotic myelopathy were retrospectively analyzed. Twenty-two patients were treated with a Zero-P implant (Group A) and 25 with a titanium plate with cage (Group B) between January 2009 and September 2010. Operative time, intraoperative blood loss, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores and JOA recovery rate, dysphagia incidence and adjacent segment degeneration rate were measured. The mean operative time in Group A and Group B was 98.18 minutes and 105.4 minutes, respectively. The average intraoperative blood loss in Group A and Group B was 87.95 ml and 92.4 ml, respectively. There were no statistical differences in operation time and intraoperative blood loss between the two groups (p>0.05). The JOA score was significantly improved in the two groups (p<0.001), and the recovery rate was similar (60.86% for Group A versus 62.95% for Group B, p>0.05). Dysphagia was experienced by one (4.5%) patient in Group A and eight (32%) patients in Group B, which was significantly different (p=0.044). There was no statistical significance found in the adjacent level degeneration rates between Group A and Group B (p=0.330). The Zero-P implant and traditional titanium plate with cage are effective treatments for single level cervical spondylotic myelopathy, but the Zero-P implant has a lower dysphagia incidence.