Guibin Zhong

Comparison of plate-cage construct and stand-alone anchored spacer in the surgical treatment of three-level cervical spondylotic myelopathy: a preliminary clinical study

BACKGROUND CONTEXT Although stand-alone cages were advocated to be superior to plate-cage construct (PCC) because of comparable clinical outcomes and fewer plate-related complications, cage dislocation and subsidence were frequently mentioned in multilevel fusion. There are some concerns about whether these issues can be effectively prevented in multilevel anterior cervical discectomy and fusion (ACDF) by stand-alone anchored spacer (SAAS). PURPOSE The aim was to compare clinical outcomes, radiologic parameters, and complications of PCC and SAAS in the treatment of three-level cervical spondylotic myelopathy (CSM). STUDY DESIGN/SETTING This was a retrospective comparative study. PATIENT SAMPLE A total of 38 consecutive patients with three-level CSM (ACDF with PCC, 20 patients; ACDF with SAAS, 18 patients) were reviewed. OUTCOME MEASURES Clinical outcomes were assessed using Japanese Orthopaedic Association and Neck Disability Index. The radiologic evaluations included cervical alignment (CA), segmental angle (SA), postoperative curvature loss (PCL), and incidence of subsidence. METHODS All the aforementioned parameters were compared before and after surgery between two groups. Besides, the aforementioned results were also compared between the two groups. The complications were also recorded. RESULTS The mean follow-up period was 30.3 months. No significant differences were observed in clinical outcomes between the two groups (p>.05). Additionally, no significant differences existed in fusion rate between the two groups. There were significant differences in PCL of SA and CA and correction of SA between the two groups (p<.05). Besides, the incidence of subsidence (9 of 54 levels, 16.7%) was recorded in the SAAS group, and the potential of SAAS to reduce the incidence of postoperative dysphagia was not proven. No other complications were observed in this study. CONCLUSIONS In the surgical treatment of three-level CSM, PCC is superior to SAAS in correction and maintenance of SA and avoiding cage subsidence, although the technique of ACDF with SAAS yielded encouraging clinical outcomes and high fusion rate.

Laminoplasty versus laminectomy for multi-level cervical spondylotic myelopathy: a systematic review of the literature.

BackgroundThere is considerable controversy as to which posterior technique is best for the treatment of multi-level cervical spondylotic myelopathy. The aim of this study was to compare the clinical and radiographic results and complications of laminoplasty (LAMP) and laminectomy (LAMT) in the treatment of multi-level cervical spondylotic myelopathy.MethodsWe reviewed and analyzed papers published from January 1966 and June 2013 regarding the comparison of LAMP and LAMT for multi-level cervical spondylotic myelopathy. Statistical comparisons were made when appropriate.ResultsFifteen studies were included in this systematic review. There was no significant difference in the incidence of surgical complications between LAMP and LAMT. Compared to conventional LAMT and skip LAMT, postoperative ROM was more limited in LAMP, but this was still superior to postoperative ROM following LAMT with fusion. Postoperative kyphosis occurred in 8/180 (4.44%) in LAMP and 13/205 (6.34%) in LAMT, whereas no cases of kyphosis were reported for skip LAMT. Skip LAMT appears to have better clinical outcomes than LAMP, while the outcome was similar between LAMP and LAMT with fusion.ConclusionsBased on these results, a claim of superiority for laminoplasty or laminectomy was not justified. In deciding between the two procedures, the risks of surgical and neurological complications, and radiologic and clinical outcome, must be taken into consideration if both options are available in multi-level cervical spondylotic myelopathy.

Posterior unilateral pedicle subtraction osteotomy of hemivertebra for correction of the adolescent congenital spinal deformity.

BACKGROUND CONTEXT The treatment of adolescent congenital deformity (late-diagnosed congenital deformity) is still unknown. The best candidates for hemivertebra excision are young patients, typically between 4 and 6 years of age. Partial excision may be feasible for older children. PURPOSE The purpose of this study was to assess the effect of unilateral pedicle subtraction osteotomy of hemivertebra for correction of the adolescent congenital spinal deformity. STUDY DESIGN Retrospective analysis. PATIENT SAMPLE Twelve patients with adolescent congenital deformity who underwent posterior unilateral pedicle subtraction osteotomy and correction were evaluated. Mean age at the time of surgery was 17 years. OUTCOME MEASURES The charts, standing full-length posteroanterior and lateral view radiographs, and functional measures were reviewed. METHODS For evaluation of surgical effectiveness, comparative analysis of the parameters of the total main curve, the segmental curve, the compensatory cranial and caudal curves, the segmental kyphosis, and the trunk shift before and after operation and at the most recent follow-up was done. RESULTS The mean follow-up period was 40.5 months. Mean Cobb angles of the total main curve and the segmental curve were, respectively, 47.5° and 43.8° before surgery, 23.7° and 16.5° after surgery, and 22.6° and 17° at the last follow-up. The angle of segmental kyphosis was 11.8° before surgery, 6.2° after surgery, and 7.8° (range, -30° to 26°) at the final follow-up. The mean final global lordosis was within the normal range. No neurologic deficit occurred. Solid fusion was achieved for all cases. CONCLUSIONS Unilateral pedicle subtraction osteotomy with instrumentation from a posterior-only approach is indicated in older teenagers for an adolescent congenital spinal deformity. Compared with hemivertebra excision, corrective surgery with hemivertebra osteotomy has a lower intraoperative blood loss and shorter operation time.

Hypertrophy of Ligamentum Flavum in Lumbar Spine Stenosis Is Associated with Increased miR-155 Level

Hypertrophy of ligamentum flavum (LF) contributes to lumbar spinal stenosis (LSS) and is caused mainly by fibrosis. Recent data indicate that miR-155 plays a crucial role in the pathogenesis of different fibrotic diseases. This study aimed to test the hypothesis that miR-155 exerts effects on LF thickness by regulating collagen expression. We found that LF thickness and the expression of collagen I and, collagen III were higher in LF from LSS patients than in LF from lumbar disc herniation (LDH) patients (P < 0.01). The expression of miR-155 was significantly higher in LF from LSS group than in LF from LDH group (P < 0.01). miR-155 level was positively correlated with LF thickness (r = 0.958, P < 0.01), type I collagen level (r = 0.825, P < 0.01), and type III collagen level (r = 0.827, P < 0.01). miR-155 mimic increased mRNA and protein expression of collagen I and collagen III in fibroblasts isolated from LF, while miR-155 sponge decreased mRNA and protein expression of collagen I and III in fibroblasts. In conclusions, miR-155 is a fibrosis-associated miRNA and may play important role in the pathogenesis of LF hypertrophy.

An Agonist of the Protective Factor SIRT1 Improves Functional Recovery and Promotes Neuronal Survival by Attenuating Inflammation after Spinal Cord Injury

Targeting posttraumatic inflammation is crucial for improving locomotor function. SIRT1 has been shown to play a critical role in disease processes such as hepatic inflammation, rheumatoid arthritis, and acute lung inflammation by regulating inflammation. However, the role of SIRT1 in spinal cord injury (SCI) is unknown. We hypothesized that SIRT1 plays an important role in improving locomotor function after SCI by regulating neuroinflammation. In this study, we investigate the effect of SIRT1 in SCI using pharmacological intervention (SRT1720) and the Mx1-Cre/loxP recombination system to knock out target genes. First, we found that SIRT1 expression at the injured lesion site of wild-type (WT) mice (C57BL/6) decreased 4 h after SCI and lasted for 3 d. Moreover, administration of SRT1720, an agonist of SIRT1, to WT mice significantly improved functional recovery for up to 28 d after injury by reducing the levels of proinflammatory cytokines, the number of M1 macrophages, the number of macrophages/microglia, and the accumulation of perivascular macrophages. In contrast, administration of SRT1720 to SIRT1 knock-out (KO) mice did not improve locomotor recovery or attenuate inflammation. Furthermore, SIRT1 KO mice exhibited worse locomotor recovery, increased levels of inflammatory cytokines, and more M1 macrophages and perivascular macrophages than those of WT mice after SCI. Together, these findings indicate that SRT1720, an SIRT1 agonist, can improve functional recovery by attenuating inflammation after SCI. Therefore, SIRT1 is not only a protective factor but also an anti-inflammatory molecule that exerts beneficial effects on locomotor function after SCI. SIGNIFICANCE STATEMENT Posttraumatic inflammation plays a central role in regulating the pathogenesis of spinal cord injury (SCI). Here, new data show that administration of SRT1720, an SIRT1 agonist, to wild-type (WT) mice significantly improved outcomes after SCI, most likely by reducing the levels of inflammatory cytokines, the number of macrophages/microglia, perivascular macrophages, and M1 macrophages. In contrast, SIRT1 KO mice exhibited worse locomotor recovery than that of WT mice due to aggravated inflammation. Taken together, the results of this study expand upon the previous understanding of the functions and mechanisms of SIRT1 in neuroinflammation following injury to the CNS, suggesting that SIRT1 plays a critical role in regulating neuroinflammation following CNS injury and may be a novel therapeutic target for post-SCI intervention.

Application of a stand-alone anchored spacer in noncontiguous anterior cervical arthrodesis with radiologic analysis of the intermediate segment

The purpose of this study was to describe the clinical features of noncontiguous cervical degenerative disc disease (cDDD), investigate the efficacy and complications of a stand-alone anchored spacer (SAAS) for patients with noncontiguous cDDD, and present radiologic analysis of the intermediate segment (IS) after skip-level fusion. Nineteen consecutive patients with noncontiguous cDDD who underwent skip-level anterior cervical discectomy and fusion (ACDF) with SAAS from January 2010 to December 2012 were enrolled in this study. Clinical outcomes were assessed preoperatively and at 24 months postoperatively using the Japanese Orthopaedic Association score, Neck Disability Index, and Visual Analog Scale. Overall cervical alignment (OCA) of the cervical spine, and the range of motion (ROM), intervertebral disc height (IDH), disc signal intensity and disc protrusion of IS were measured and compared before and after surgery. Clinical outcomes significantly improved compared to preoperative scores. The OCA was corrected and maintained at 24 months postoperatively compared with preoperative values (p<0.05). There were no significant differences in the ROM and IDH of the IS at each follow-up (p>0.05). However, decreased signal intensity on T2-weighted MRI was evidenced in three mobile IS at final follow-up (20.0%). Skip-level ACDF with SAAS may be an efficacious option for the treatment of noncontiguous cDDD.

Surgical treatment for cervical spondylotic myelopathy in elderly patients: A retrospective study

OBJECTIVE To analyze perioperetive clinical features and outcomes of surgical treatment for cervical spondylotic myelopathy (CSM) in elderly patients. METHODS From 2006 to 2013, we retrospectively reviewed 136 patients with CSM who underwent surgery. The patients were divided into two groups: 70 years or older (elderly group, 58 patients) and younger than 70 years (younger group, 78 patients). The course of disease, surgical outcome, morbidities, and postoperative complications were analyzed. RESULTS In the elderly group, follow-up lasted 9-76 months (mean 39.6 months), the course of disease was 23.7 months (range 4-72 months). Anterior cervical decompression and fusions and posterior laminectomy and fixation were performed in 24 and 34 patients, respectively. The operative time averaged 103 min (range 48-210 min). In the younger group, follow-up lasted 10-71 months (mean 37.8 months), the course of disease was 12.6 months (range 2-58 months). Anterior cervical decompression and fusions and posterior laminectomy and fixation were performed in 75 and three patients, respectively. The prevalence of chronic diseases and postoperative complications were higher in the elderly group than the younger group. The recovery rates of JOA score were 40.82 ± 11.20% in the elderly group and 64.10 ± 22.61% in the younger group. The therapeutic effects of surgery were significantly better for the young patients than for the elderly. CONCLUSION Elderly patients with CSM present long period and serious symptoms, and the degeneration of multiple organs. Surgical decompression for CSM appears to be a beneficial and safe procedure for older patients if properly handled, although the recovery rate is poorer than that of younger patients.

Dynamic response of the idiopathic scoliotic spine to axial cyclic loads.

Study Design. Numerical techniques were used to study the vibration response of idiopathic scoliosis patients with single thoracic curve. Objective. To analyze the dynamic characteristics of the idiopathic scoliotic spine under the whole-body vibration condition. The influence of the upper body mass was also studied. Summary of Background Data. The relationship between the whole-body vibration and the spinal disorders has been investigated using fitnite element method. However, the dynamic response features of the scoliotic spine to the vibration were poorly understood. Methods. The resonant frequencies of the scoliotic spine and the effects of the body weight were studied using a fitnite element model described previously. Modal and harmonic analysis was conducted. The amplitudes of 6 fundamental vertebral movements around the long, coronal and sagittal axis were quantifited in the frequency range of 1 to 35 Hz. Results. The vibration-induced rotation amplitudes of the apex of the thoracic deformity were higher than that of the lumbar segments. The apical vertebrae had the greatest rotation amplitudes at 2 and 8 Hz, and the largest lateral translation amplitudes at 16 Hz. Vibration could cause large lateral flexion amplitudes in the apex of the thoracic deformity. The apical vertebrae had the largest side flexion amplitudes at 6 Hz. Increasing upper body mass could not change resonant frequency of vibration-induced lateral translation and rotation around the long axis of the apical vertebrae. Conclusion. The scoliotic spine is more sensitive to vibration than the normal spine. For a patient with single thoracic curve, long-term whole-body vibration may do more harm to the thoracic deformity than to the lower lumbar segments. Axial cyclic loads applied to an already deformed spine may cause further rotational and scoliotic deformity. The patients with idiopathic scoliosis are more likely to suffer from vibration-induced spinal disorders than those by normal persons.

Kinetic Magnetic Resonance Imaging Analysis of Spinal Degeneration: a Systematic Review

To evaluate the clinical use of kinetic magnetic resonance imaging (kMRI) in spinal degenerative diseases.

Split Spinal Cord Malformation: Report of 5 Cases in a Single Chinese Center and Review of the Literature

Background: Split spinal cord malformation (SSCM) is rare in scoliosis. This study evaluated the safety and effectiveness of one-stage surgical treatment of congenital scoliosis (CS) in patients with SSCM in a single Chinese center. Method: A retrospective study of 5 cases who underwent surgery for CS with SSCM (2 type I and 3 type II) from March 2004 to March 2012. Patients included 4 females and 1 male with a mean age of 13.8 years. All patients underwent one-stage posterior fusion surgery with resection of a bony spur firstly in SSCM type I, but we did nothing to the SSCM in type II. Clinical symptoms and radiological changes were evaluated preoperatively and for at least 2 years postoperatively. Results: Preoperatively, 5 patients had variant neurological and other symptoms. They had a mean preoperative Cobb angle of 63 ± 20° and T5-T12 kyphosis of 30 ± 21°. The mean postoperative Cobb angle was 30.2 ± 19.8° with a correction rate of 57.2 ± 17.0%. At the 3-month follow-up the Cobb angle loss was 3.0 ± 6.8°, and at the 2-year follow-up the Cobb angle loss was 6.5 ± 9.7°. Hyperkyphosis was significantly corrected after surgery but correction loss was indicated at the 2-year follow-up (p < 0.01). There were no neurological deficit complications or deteriorated neurological signs postoperatively or at follow-up. Conclusions: One-stage surgical treatment of CS with SSCM could be safe and effective, but we need further multicenter studies with larger samples. Intraspinal intervention of bone spur was recommended in SSCM type I before deformity correction, while in SSCM type II it was needless.