Feasibility of microwave ablation of the vertebral growth plate for spine growth regulation: a preliminary study.

PURPOSE: To explore the feasibility of microwave ablation (MWA) of the vertebral growth plate as a minimally invasive treatment for early-onset scoliosis. MATERIALS AND METHODS: One side of the L1-L3 vertebral growth plates were ablated using different MWA powers. Ablation safety and size were examined. Subsequently, L1-L3 vertebral growth plates were ablated on one side for 40 s at 20 W. At 2, 4, and 6 weeks after the ablation, growth changes of the spine were observed. RESULTS: No piglets died during and after ablation, and all had modified Tarlov Grade 5. The safe MWA time (time for safely ablating the vertebral growth plate) was 17.0 ± 1.5 s at 50 W, 23.0 ± 2.3 s at 40 W, 31.0 ± 3.1 s at 30 W, 47.0 ± 3.7 s at 20 W, 70.0 ± 4.2 s at 15 W, and 158.0 ± 5.0 s at 10 W. With power <15 W, the vertebral growth plate could not be effectively ablated within the safe ablation time. Within the safe ablation times, the MWA size on hematoxylin and eosin slices on a transverse diameter was between 7 and 10 mm; and that on longitudinal diameter was mainly determined by the ablation needle length. Moreover, the growth plate and annulus fibrosus on the ablated side grew poorly over time, the vertebral body showed significant wedge-shaped changes, and the spine showed significant unbalanced growth. CONCLUSION: MWA of the vertebral growth plate can be performed safely when accompanied with appropriate thermometry, and could be a new minimally invasive strategy in regulating spine growth.

Effect of Spinal Shortening for Protection of Spinal Cord Function in Canines with Spinal Cord Angulation.

BACKGROUND Posterior vertebral column resection (PVCR) has been widely used as a treatment for severe spinal deformity. By using the canine model of vertebral column resection, this study explored the effect of spinal shortening on blood flow and function of the spinal cord during spinal cord angulation. MATERIAL AND METHODS The canine model of L1 vertebral column resection was constructed with the PVCR technique. The canines were divided into 5 groups according to the degree of shortening: the 0/4 group, the 1/4 group, the 2/4 group, the 3/4 group, and the control group. Spinal cord blood flow, neuroelectrophysiology, HE staining, nitric oxide, and endothelin-1 were measured during the procedure of vertebral column resection and spinal cord angulation. RESULTS The results showed that, in the 1/4 group and the 2/4 group, the blood flow of the spinal cord decreased by 16.5% and 10.6%, respectively, with no obvious damage in the spinal cord; in the 0/4 group and the 3/4 group, the blood flow decreased by 23.5% and 23.1%, respectively, with significant damage in the spinal cord. CONCLUSIONS When the spinal cord is shortened by 1/4 to 2/4, the tolerance of the spinal cord can increase and spinal cord injury resulting from angulation can be avoided. However, when the shortening reaches 3/4, it is harmful to the spinal cord. Proper shortening of the spinal cord by 1/4 to 2/4 may increase the tolerance of the spinal cord to the damage caused by angulation during PVCR.

The risk factors of neurologic deficits of one-stage posterior vertebral column resection for patients with severe and rigid spinal deformities.

PURPOSE: To determine the risk factors of neurologic deficits during PVCR correction, so as to help improve safety during and after surgery. METHODS: A consecutive series of 76 patients with severe and rigid spinal deformities who were treated with PVCR at a single institution between October 2004 and July 2011 were included in our study. Of the 76 patients, 37 were male and 39 female, with an average age of 17.5 years (range 10-48 years). There were 52 adolescent patients (with an age <18 years) and 24 adult patients (with an age ≥18 years). Preoperatively, postoperatively and 6 months after surgery, we performed systemically neurologic function evaluations of each patients through meticulous physical examination. Any new abnormality or deterioration in evaluation of neurologic function than preoperative is reckoned postoperative neurologic deficits. Ten variables that might affect the safety of neurologic deficits during PVCR procedures, including imaging factors, clinical factors and operational factors, were analyzed using univariate analysis. Then the variables with statistical difference were analyzed by using multi-factor unconditional logistic regression analysis. RESULTS: No patient in this series had permanent paraplegia and nerve root injury due to operation. Change of neurologic status was found in six patients after surgery. Results of single-factor comparison demonstrated that the following seven variables were statistically different (P < 0.05): location of apex at main curve (X 3), Cobb angle at the main curve at the coronal plane (X 4), scoliosis associated with thoracic hyperkyphosis (X 5), level of vertebral column resected (X 6), number of segmental vessels ligated (X 7), preexisting neurologic dysfunction (X 8), and associated with intraspinal and brain stem anomalies (X 9). The multi-factor unconditional logistic regression analysis revealed that X 8 (OR = 49.322), X 9 (OR = 18.423), X 5 (OR = 11.883), and X 6 (OR = 8.769) were independent and positively correlated with the neurologic deficit. CONCLUSIONS: Preexisting neurologic dysfunction, associated with intraspinal and brain stem anomalies, scoliosis associated with thoracic hyperkyphosis and level of vertebral column resected are independent risk factors for neurologic deficits during PVCR procedure.

A five-step remedial screw placement method to treat severe spinal deformity with free-hand transpedicular screw placement.

PURPOSE: Severe spinal deformity is a complex morphological deformation that occurs and develops in three-dimensional space combined with abnormal development and morphology of anatomical structures, which presents great difficulties in the process of transpedicular screw placement. This study tried to explore the methods of transpedicular screw placement in surgical correction of severe spinal deformities. METHODS: Surgical corrections through posterior approach were performed in all the 76 cases (mean age 20.4 years). The averaging preoperative Cobb's angle of scoliosis was 108.2° ± 33.6° (range 100°-170°). Among these patients, 34 cases were combined with kyphosis; the average Cobb's angle of kyphosis was 77.3° (range 63°-160°). During operation, the screw tract was first established with the regular free-hand pedicle screw placement method. When this failed, in order to adjust the screw trajectory, a five-step remedial method was performed in the following order: (1) the"funnel" method; (2) exploring the pedicle exterior edge through the costotransverse joint; (3) exploring the superior and inferior edges of pedicle through the nerve root canal; (4) the vertebral plate fenestration; and (5) hemilaminectomy. RESULTS: Among all 1,472 screws planned to be placed for the patients, 1,210 (82.2 %) were successfully placed after using the regular method, and 262 (17.8 %) failed in this stage. After applying the five-step remedial method, 256 of the failed 262 screws were successfully placed. Among them, 176 screws (68.8 %) were successfully placed after Step 1, 44 (17.2 %) after Step 2, 21 (8.2 %) after Step 3, 12 (4.7 %) after Step 4, and 3 (1.2 %) after Step 5. In only six, pedicles screws could not be placed eventually. No nerve or blood vessel damages occurred in all cases. All final screw positions were validated by CT. CONCLUSION: The five-step remedial method proved to be an effective supplementary method for transpedicular screw placement to treat patients with severe spinal deformities. The key points include a detailed preoperative plan, a meticulous hand drilling sensation, and an experienced probing technique for screw tract.

Upregulation of JHDM1D-AS1 alleviates neuroinflammation and neuronal injury via targeting miR-101-3p-DUSP1 in spinal cord after brachial plexus injury.

BACKGROUND: Neuroinflammation in the spinal cord following acute brachial plexus injury (BPI) remains a vital cause that leads to motor dysfunction and neuropathic pain. In this study, we aim to explore the role of long non-coding RNA JHDM1D antisense 1 (JHDM1D-AS1) in mediating BPI-induced neuroinflammation and neuronal injury. METHODS: A total brachial plexus root avulsion (tBPRA) model in adult rats and IL-1ß-treated motor neuron-like NSC-34 cells and LPS-treated microglia cell line BV2 were conducted for in vivo and in vitro experiments, respectively. The expressions of JHDM1D-AS1, miR-101-3p and DUSP1, p38, NF-κB, TNF-α, IL-1ß, and IL-6 were detected by RT-PCR and western blot seven days after tBPI. Immunohistochemistry (IHC) was used to detect neuronal apoptosis. CCK8 assay, Tunel assay and LDH kit were used for the detection of neuronal injury. The targeted relationships between JHDM1D-AS1 and miR-101-3p, miR-101-3p and DUSP1 were verified by RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assay. RESULTS: We found significant downregulated expression of JHDM1D-AS1 and DUSP1 but upregulated expression of miR-101-3p in the spinal cord after tBPI. Overexpression of JHDM1D-AS1 had a prominent neuroprotective effect by suppressing neuronal apoptosis and microglial inflammation through reactivation of DUSP1. Further exploration revealed that JHDM1D-AS1 may act as a competitive endogenous RNA targeting miR-101-3p, which bound on the 3'UTR of DUSP1 mRNA. In addition, overexpression of miR-101-3p could reverse the neuroprotective effects of JHDM1D-AS1 upregulation by blocking DUSP1. CONCLUSIONS: JHDM1D-AS1 exerted neuroprotective and anti-inflammatory effects in a rat model of tBPI by regulating miR-101-3p/DUSP1 axis.

Cervical Abnormalities in Severe Spinal Deformity: A 10-year MRI Review.

OBJECTIVE: To investigate the incidence of cervical anomalies (CA), including cervical intraspinal neural axis abnormalities (CIINAA) and/or cervical osseous abnormalities (COA), and the clinical relevance in severe spinal deformities (SSD) at a single center. METHODS: A retrospective study of SSD admitted for spinal surgery from January 2003 to January 2015 was conducted at a single center. INCLUSION CRITERIA: patients who present with coronal Cobb over 90° (and/or sagittal cobb ≥90°); and patients with complete imaging and clinical data preoperatively. EXCLUSION CRITERIA: ankylosing spondylitis, adult onset scoliosis, scoliosis secondary to bone destruction. There were 108 SSD patients who fulfilled the criteria in this research (41 males and 67 females). The mean age of the patients was 18.1 ± 2.7 years (range, 10-45 years). The clinical and radiological data of these patients were reviewed to identify CA and to analyze the relationship between clinical and radiographic characteristics in the population of SSD. RESULTS: The major curves of scoliosis and segmental kyphosis were 109.1° ± 24.7° and 91.2° ± 29.1°. Cervical abnormalities were detected in 56 patients (51.85%) with 9 different CA, including 28 patients (25.9%) with 6 different COA, 21 patients (19.4%) with 3 different CIINAA, and 7 patients (6.5%) with a combination of COA and cervical intraspinal neural axis abnormalities (CINAA). Basilar invagination and Klippel-Feil syndrome were the most frequent COA. Syringomyelia was the most frequent CINAA. SSD with COA in upper vertebral levels (UVL) had a higher incidence of CINAA than those in subaxial vertebral levels (SVL) (P = 0.024) and SSD with multiple COA (mCOA) in UVL had a higher incidence of CINAA than those with single COA (sCOA) (P = 0.029). In the present study, 83.9% of the SSD with CA were asymptomatic. CONCLUSION: The incidence of CA in SSD was 51.85%, with most presenting with intact neurologic status. As the diversity of COA increased, we found a higher incidence of CINAA, especially in UVL.

Improvement of chloroperoxidase stability by covalent immobilization on chitosan membranes.

Chloroperoxidase (CPO) from Caldariomyces fumago was optimally covalently immobilized on chitosan membranes pretreated with 0.8 M glutaraldehyde at pH 3.5 to give 3.18 mg CPO g(-1) support. Using monochlorodimedone (MCD) as assay substrate, the immobilized-CPO retained 40% activity at 50 degrees C after 40 min whereas free CPO retained only 0.02%. The residual activity for immobilized-CPO was 99 and 58% compared with 68 and 43% for free CPO in the presence of 1.5 M urea and 300 microM H(2)O(2), respectively, after 20 h.

Expert consensus for PVCR in severe, rigid and angular spinal deformity treatment: The Kunming consensus.

In the past decades, an increasing number of surgeons started using posterior vertebral column resection (PVCR) to treat severe, rigid and angular spinal deformities. Little high-level evidence is available to guide surgical treatment. The aims of our study were to identify important surgical strategies and key technical points of Chinese experts who have extensive experience in the management of severe, rigid and angular spinal deformities using PVCR, and to standardize and unify the current core concepts. Workgroups of consensus were formed by selecting nationwide representing experts and comprehensive consultations. Eight task forces for major issues were established, then retrieval of literature, collection of expert opinions and writing of review articles were carried out. A modified Delphi process was chosen in round-table forum with three face-to-face meetings. Consensus was reached with items graded more than seven points including: indications and contraindications of PVCR; review PVCR in the evolution of spinal osteotomies; The corrective mechanism and safety of spinal cord; monitoring and responses of spinal cord crisis; characteristics and therapeutic outcome of pulmonary function; management of bleeding during PVCR; relationship of pedicle screw insertion and spinal cord safety; and analysis of non-neurologic complications and prevention strategies. In conclusion, The essential properties regarding PVCR procedure are tightly linked with various factors such as medical and surgical indication, range and level of vertebral column resection, strategies of correction, corrective efficiency and control of neurological risk. PVCR is used mainly for severe, rigid spinal deformity that is not manageable by other osteotomy techniques.