Cell-Free Extracts from Human Fat Tissue with a Hyaluronan-Based Hydrogel Attenuate Inflammation in a Spinal Cord Injury Model through M2 Microglia/Microphage Polarization.

Treatment for spinal cord injuries (SCIs) is often ineffective because SCIs result in a loss of nerve tissue, glial scar formation, local ischemia and secondary inflammation. The current promising strategy for SCI is the combination of bioactive materials and cytokines. Bioactive materials support the injured spinal cord, stabilize the morphology, and avoid excessive inflammatory responses. Fat extract (FE) is a cell-free liquid component containing a variety of cytokines extracted from human fat tissue using mechanical methods. In this research, a biocompatible HAMC (hyaluronan and methylcellulose) loaded with FE is used to treat a model of spinal cord contusion in mice. The composite not only inhibits death of neuro- and vascular cells and leads to the preservation of neural and vascular structure, but also modulates the inflammatory phenotype of macrophages in the locally injured region. Specifically, FE promotes the polarization of macrophages from an inflammatory M1 phenotype to an anti-inflammatory M2 phenotype. During the screening of the involved pathways, it is corroborated that activation of the STAT6/Arg-1 signaling pathway is involved in macrophage M2 polarization. In summary, FE is a promising treatment for SCI, as it is easy to obtain, nonimmunogenic, and effective.

Electrophysiological differences between Hirayama disease, amyotrophic lateral sclerosis and cervical spondylotic amyotrophy.

BACKGROUND: Hirayama disease (HD), amyotrophic lateral sclerosis (ALS) or cervical spondylotic amyotrophy (CSA) may result in atrophy of intrinsic hand and forearm muscles. The incidence of HD is low, and it is rarely encountered in the clinical setting. Consequently, HD is often misdiagnosed as ALS or CSA. It is important to differentiate these diseases because HD is caused by a benign focal lesion that is limited to the upper limbs. METHODS: The thenar and hypothenar compound muscle action potential (CMAP) amplitude of the upper limbs of 100 HD, 97 ALS and 32 CSA cases were reviewed; 35 healthy individuals were included as controls. Seventy-eight percent, 38% and 69% of patients with HD, ALS or CSA had unilateral involvement; the remaining patients were affected bilaterally. Thenar and hypothenar CMAP amplitude evoked by ulnar stimulation was compared with CMAP evoked by median stimulation. RESULTS: The ulnar/median CMAP ratio was found to be lower in HD (0.55 ± 0.41, P<0.0001), higher in ALS (2.28 ± 1.15, P<0.0001) and no different in CSA (1.21 ± 0.53, P>0.05) compared with the normal range from previous studies (0.89-1.60) and with the healthy controls (1.15 ± 0.23). Conduction velocities of the sensory and motor nerves, the amplitude of the sensory nerve action potential, and the CMAP amplitude of the unaffected limb were all normal. CONCLUSIONS: The hand muscles were differentially affected between patients with HD, ALS and CSA. The ulnar/median CMAP ratio could be used to distinguish these three diseases.

Effect of rat brain tissue extracts on osteoblast proliferation and differentiation.

PURPOSE: The reason for enhanced fracture healing in traumatic brain injury patients is not clearly understood. It is possible that factors inherent in the brain passing through the blood-brain barrier to the peripheral circulation, or a disruption of central nervous system (CNS) control of the sympathetic nervous system (SNS), stimulates the process of fracture healing. METHODS: In this study, we assessed proliferation [using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay] and differentiation [using alkaline phosphatase (ALP)] in rat osteoblasts incubated with gray matter or other tissue extracts with and without the addition of an α- or ß-adrenergic receptor blocker (phentolamine or propranolol). RESULTS: Gray matter extract from normal brain caused a dose-dependent increase in osteoblast proliferation and differentiation. Serum from normal rats enhanced differentiation but not proliferation. Alpha-receptor blockade had no effect on proliferation or differentiation. Beta-receptor blockade caused a partial, but statistically significant, decrease in gray matter stimulation of osteoblast differentiation. CONCLUSION: The results of this study indicate that gray matter extract from normal brain increases osteoblast proliferation and differentiation and that ß receptors may be involved in differentiation under these conditions.

Ankle fusion with a retrograde locked intramedullary nail for sequela of lower extremity compartment syndrome.

OBJECTIVE: To assess the value of ankle fusion with a retrograde locked intramedullary nail in the treatment of sequela of lower extremity compartment syndrome. METHODS: Thirty-five cases of equinus deformity follow-ing tibiofibular compartment syndrome treated by means of ankle fusion with a retrograde locked intramedullary nail from January 2001 to December 2010 were retrospectively reviewed. The complications, the time needed for bony fusion of the ankle joint assessed by anteroposterior and lateral X-ray photographs as well as patients'subjective evaluation were recorded and analysed. RESULTS: Among the 35 patients, 15 had previously undergone surgical treatment twice on the same limb, 13 had thrice and 7 had to be operated on four times before ankle fusion. An anterior midpoint approach to the ankle joint was adopted in 29 cases, while anterior midpoint approach plus a small incision on the posterior ankle joint was made in 17 cases, whereas lateral approach in 6 cases. Tarsus joint fusion was performed on 4 cases. The follow-up period ranged 6-124 months, averaged 40.6 months. Bone grafting was not performed in this series. Preoperative tibial shaft fracture occurred in one patient and was healed after conservative treatment. Incision dehiscence located at previous Achilles tendon incision was found in two patients. As a result, one received an intramedullary nail emplacement at calcaneoplantar part while the wound at anterosuperior part of the other one was healed by dressing change. Two patients failed to bony union 5 months postoperatively, in which one healed 10 weeks after retrieval of proximal tibial nail and another by iliac grafting. Terminal necrosis of the toe due to blood supply dysfunction was not found in this series. All the patients were satisfied with the ankle joint function postoperatively. The time for bony union on X-rays was 9.8 weeks on average. Except for one patient who demanded removal of intramedullary nail, all the intramedullary nails were not retrieved at the end of follow-up. Nail breakage happened in one patient and no other breakage or backing out of the nail was found. CONCLUSIONS: Lower extremity compartment syndrome and residual ankle deformity often extremely impact ambulation and are hard to deal with because several pathologic phenomena might exist in these patients, for instance, poor skin conditions due to repeated preexisting surgery; poor perfusion in distal limbs following blood vascular injury; reflux limitation and long-term limb swelling due to muscle strength disturbance; osteoporosis as a result of long-term immobilization or limb disuse. Ankle fusion with a retrograde locked intramedullary nail is an optimal protocol to solve these clinical symptoms and rather ensures a definite fusion and firm fixation to these patients with simple manipulation and few complications.

The Relationship Between Preoperative Cervical Sagittal Balance and Clinical Outcome of Acute Traumatic Central Cord Syndrome.

OBJECTIVE: To explore the sagittal radiological parameters related to clinical recovery of patients with acute traumatic central cord syndrome (ATCCS) and determine the diagnostic value of related variables. METHODS: A retrospective review was performed of 104 patients with ATCCS. Six cervical sagittal balance parameters were collected: Cobb angle, T1 slope, neck tilt, thoracic inlet angle (TIA), C2-C7 sagittal vertex axis, T1 slope - C2-C7 Cobb angle. The patients were assigned to an ideal improvement group and poor improvement group according to their recovery rate. Receiver operating characteristic curve and area under the curve were used to evaluate the significant results of logistic regression and the optimal diagnostic value. RESULTS: Preoperative and postoperative Japanese Orthopaedic Association scores indicated a good recovery after surgical intervention. Radiological findings revealed that neck tilt and TIA were risk factors for poor neurological improvement of patients with ATCCS. Area under the curve (95% confidence interval) values of neck tilt and TIA were 0.763 (0.660-0.866) and 0.749 (0.643-0.855), and cutoff values were 39.1° and 65.6°, respectively. CONCLUSIONS: Lower neck tilt and TIA are risk factors for poor outcomes in patients with ATCCS after surgery. Neck tilt <39° and TIA <66° had significant diagnostic value for poor prognosis.

Somatosensory evoked potential from S1 nerve root stimulation.

The objective of this study was to detect cerebral potentials elicited by proximal stimulation of the first sacral (S1) nerve root at the S1 dorsal foramen and to investigate latency and amplitude of the first cerebral potential. Tibial nerve SEP and S1 nerve root SEP were obtained from 20 healthy subjects and 5 patients with unilateral sciatic nerve or tibial nerve injury. Stimulation of the S1 nerve root was performed by a needle electrode via the S1 dorsal foramen. Cerebral potentials were recorded twice to document reproducibility. Latencies and amplitudes of the first cerebral potentials were recorded. Reproducible cerebral evoked potentials were recorded and P20s were identified in 36 of 40 limbs in the healthy subjects. The mean latency of P20 was 19.8 ± 1.6 ms. The mean amplitude of P20-N30 was 1.2 ± 0.9 µV. In the five patients, P40 of tibial nerve SEP was absent, while well-defined cerebral potentials of S1 nerve root SEP were recorded and P20 was identified from the involved side. This method may be useful in detecting S1 nerve root lesion and other disorders affecting the proximal portions of somatosensory pathway. Combined with tibial nerve SEP, it may provide useful information for diagnosis of lesions affecting the peripheral nerve versus the central portion of somatosensory pathway.

The Relationship Between Preoperative Cervical Sagittal Balance and Clinical Outcome of Patients With Hirayama Disease Treated With Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a common surgical method used to treat patients with Hirayama disease. And sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical diseases, but their relationships with ACDF-treated Hirayama disease outcomes remain unknown. The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcomes in ACDF-treated Hirayama disease patients. METHODS: Eighty patients with Hirayama disease treated by ACDF were reviewed retrospectively. Six cervical sagittal balance parameters were collected including Cobb angle, T1 slope, C1-7 sagittal vertical axis (SVA), C2-7 SVA, center of gravity of the head (CGH)-C7 SVA, range of motion. The recovery outcomes of the patients were divided into 2 groups by Odom score and the differences in recovery between the 2 groups were confirmed by electromyography. The correlation between imaging parameters and postoperative outcome was evaluated with logistic regression. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate the significant result of logistic regression and the optimal diagnostic value. RESULTS: Only 2 parameters, Cobb angle and CGH-C7 SVA, showed statistical correlation with the postoperative outcome assessment by logistic regression. AUC of Cobb angle and CGH-C7 SVA were 0.559 and 0.702 respectively. The optimal predictive threshold was 1.50° and 5.40 mm, respectively. CONCLUSION: A larger Cobb angle and smaller CGH-C7 SVA seemed to correlate with a better postoperative outcome. These 2 factors could be used to predict the outcome of surgical treatment of Hirayama disease preoperatively.

Analysis of the Effect of Surgical Treatment for the Patients with Hirayama Disease from the Perspective of Cervical Spine Sagittal Alignment.

OBJECTIVE: This study was carried out to analyze the surgical effect of cervical spine sagittal alignment for patients with Hirayama disease (HD). METHODS: Forty-four subjects were retrospectively analyzed for the parameters of cervical spine sagittal alignment. The case group consisted of 23 patients with HD, whereas the control group consisted of 21 healthy adolescent subjects. Pre- and postoperative cervical spine sagittal parameters of the patients with HD were collected; the cervical sagittal parameters of the healthy adolescent subjects were also collected. Sagittal alignment parameters were compared between the patients with HD and the healthy adolescent subjects, and between the pre- and postoperative parameters for the patients with HD. RESULTS: Forty-four subjects completed the follow-up, with the average follow-up period being 18.0 months. No significant differences were detected between the HD and control groups for clinical parameters (P > 0.05). The preoperative HD group had smaller values compared with the control group in the sagittal parameters of C2-7 cervical lordosis (CL) angle, T1 slope, thoracic inlet angle (TIA), and cervical tilt angle (P < 0.05). For the patients with HD, the preoperative values were smaller compared with the postoperative HD values for the parameters of C2-7 CL angle, T1 slope, and cervical tilt angle (P < 0.05). We found no significant differences between the postoperative patients with HD and the healthy subjects, including C2-7 CL angle, C2-7 sagittal vertical axis, T1 slope, TIA, neck tilt angle, cervical tilt angle, and cranial tilt angle (P > 0.05). CONCLUSIONS: Patients with HD have sagittal imbalance of the cervical spine compared with age-matched healthy adolescent subjects, and surgical treatment could correct the sagittal imbalance.

Exosome-Transported circRNA_0000253 Competitively Adsorbs MicroRNA-141-5p and Increases IDD.

The pathogenesis of intervertebral disc degeneration (IDD) is complex, and a better understanding of IDD pathogenesis may provide a better method for the treatment of IDD. Exosomes are 40-100 nm nanosized vesicles that are released from many cell types into the extracellular space. We speculated that exosome-transported circular RNAs (circRNAs) could regulate IDD. Exosomes from different degenerative grades were isolated and added to nucleus pulposus cells (NPCs), and indicators of proliferation and apoptosis were detected. Based on the previous circRNA microarray results, the top 10 circRNAs were selected. PCR was performed to determine the circRNA with the maximum upregulation. Competing endogenous RNA (ceRNA) analysis was carried out, and the sponged microRNA (miRNA) was identified. Further functional verification of the selected circRNA was carried out in vivo and in vitro. NPCs of different degenerative grades secreted exosomes, which could regulate IDD. circRNA_0000253 was selected as having the maximum upregulation in degenerative NPC exosomes. ceRNA analysis showed that circRNA_0000253 could adsorb miRNA-141-5p to downregulate SIRT1. circRNA_0000253 was confirmed to increase IDD by adsorbing miRNA-141-5p and downregulating SIRT1 in vivo and in vitro. Exosomal circRNA_0000253 owns the maximum upregulation in degenerative NPC exosomes and could promote IDD by adsorbing miRNA-141-5p and downregulating SIRT1.

[The anatomic study and clinical significance of the modified transforaminal lumbar interbody fusion].

OBJECTIVE: To put some improvements to the traditional transforaminal lumbar interbody fusion (TLIF) and discuss its clinical significance. METHODS: Completed the traditional posterior lumbar interbody fusion (PLIF) and TLIF procedure in 12 fresh cadavers, dissect further to expose the surrounding anatomical structures, and put the modified TLIF surgery according to the anatomical findings. And simulated the operation in 12 fresh cadavers, analyzed its feasibility and potential advantages. RESULTS: The early anatomical study found that the related nerve root was in a state of high tension and certain risk of injury when completed the traditional PLIF and TLIF surgery, and found certain operational area between the superior articular process and the midline structures of the spinous processes and interspinous ligaments. Put the modified TLIF surgical approach according to the anatomical findings, which the operating area is located in PLIF outside and TLIF inside. As the following words: Take a posterior-middle incision, preserve the supraspinous and interspinous ligaments, and the spinous processes, dissect the bilateral paravertebral muscle, expose lamina and facet joints, not including transverse process, and remove unilateral inferior two third lamina, inferior articular process and expose the articular surface of the superior articular process, then dispose the intervertebral space for interbody fusion obliquely in the unilateral approach. Successfully completed the modified TLIF procedure in 12 fresh cadavers, the results showed that the technique has the following advantages. (1) Only remove unilateral inferior two third lamina and inferior articular process, preserve the supraspinous and interspinous ligaments, and the spinous processes, not expose the transverse process. (2) Both central canal, and lateral recess and nerve root canal of the operative side can be decompressed effectively simultaneously. (3) Avoid excessive traction to the thecal sac and traversing nerve roots and decrease the injury rate due to the reservation of the midline structures and the oblique manipulation, and less injury rate of the exiting nerve root, because of not necessary to expose it routinely. CONCLUSIONS: The modified TLIF is safe and feasible, could effectively reduce the nerve roots injuries. Maybe it's a better choice for most of the Chinese patients at present.

Risk Factors of Adjacent Segment Disease After Anterior Cervical Arthrodesis: A Retrospective Study of Sagittal Measurement of Thoracic Inlet Parameters.

BACKGROUND: To explore the predictive parameters for adjacent segment disease (ASD) after anterior cervical arthrodesis at the sagittal measurement of thoracic inlet. METHODS: We included 212 subjects treated with anterior cervical fusion surgery to identify predictive parameters for ASD. We applied multivariate logistic regression to find the relevant parameters. RESULTS: Two hundred patients completed the final follow-up. The results of logistic regression analysis showed that T1 slope of less than 19.50 could be a predictive parameter of ASD after the anterior cervical arthrodesis (P < 0.05). CONCLUSIONS: Sagittal balance of thoracic inlet is vital to avoid the. cervical degenerative disease, while T1 slope of less than 19.50 appears to be an independent risk factor for the ASD, keeping the T1 slope of more than 19.5 is reasonable.

Cortical Activation Changes in Hirayama Disease After Anterior Cervical Decompression and Fusion.

BACKGROUND: Spinal cord injury may cause cortical reconstruction. We, therefore explored the changes in cortical activation before and after anterior cervical decompression and fusion surgery in patients with Hirayama disease (HD). METHODS: In total, 17 cases with HD underwent anterior cervical decompression and fusion surgery. Blood oxygenation level-dependent functional magnetic resonance imaging scan was performed preoperatively, 3 months, 6 months, and 1 year after surgery. Activated voxels were compared between both hands after adjusting for head motion, slice timing, spatial normalization, and image smoothing. Grip strength also was tested in both hands. RESULTS: A retrospective review indicated that the grip strength of the asymptomatic hand was significantly stronger than the symptomatic hand at the time point before the surgery, 3 months after surgery, 6 months after surgery, and 1 year after surgery (P < 0.001). The grip strength of both symptomatic and asymptomatic hands continuously increased within 6 months after surgery (P < 0.05), but it stopped at 1 year after the surgery. The symptomatic limb tends to produce bilateral activation in the primary motor area (M1) during motor tasks. Both contralateral and ipsilateral M1 activation were stronger in symptomatic hand tasks preoperatively (P < 0.05). Both contralateral and ipsilateral activation in M1 during symptomatic hand tasks began to reduce after surgery, and statistical significance was observed 6 months after surgery (P < 0.05). Contralateral activation was relatively even over 6 months of the surgery (P > 0.05). CONCLUSIONS: After surgery, pathologic reconstruction may have occurred in the primary motor cortex. Recovery of motor function in the symptomatic limb was accompanied by decreased ipsilateral and contralateral M1 activation, as well as symptom improvement. These findings suggested that postoperative cortical activation changes may reflect functional recovery in HD.

CircularRNA_104670 plays a critical role in intervertebral disc degeneration by functioning as a ceRNA.

This study was carried out to explore the roles of circular RNAs (circRNAs) in nucleus pulposus (NP) tissues in intervertebral disc degeneration (IDD). Differentially expressed circRNAs in IDD and normal NP tissues were identified based on the results of microarray analysis. Bioinformatics techniques were employed to predict the direct interactions of selected circRNAs, microRNAs (miR), and mRNAs. CircRNA_104670 was selected as the target circRNA due to its large multiplier expression in IDD tissues. After luciferase reporter and EGFP/RFP reporter assays, we confirmed that circRNA_104670 directly bound to miR-17-3p, while MMP-2 was the direct target of miR-17-3p. The receiver-operating characteristic (ROC) curve showed that circRNA_104670 and miR-17-3p had good diagnostic significance for IDD (AUC circRNA_104670 = 0.96; AUC miRNA-17-3p = 0.91). A significant correlation was detected between the Pfirrmann grade and expression of circRNA_104670 (r = 0.63; p = 0.00) and miR-17-3p (r = -0.62; p = 0.00). Flow-cytometric analysis and the MTT assay showed that interfering with circRNA_104670 using small interfering RNA (siRNA) inhibited NP cell apoptosis (p < 0.01), and this inhibition was reduced by interfering with miR-17-3p. Interfering with circRNA_104670 suppressed MMP-2 expression and increased extracellular matrix (ECM) formation, which were also reduced by interfering with miR-17-3p. Finally, an MRI evaluation showed that circRNA_104670 inhibition mice had a lower IDD grade compared with control mice (p < 0.01), whereas circRNA_104670 and miRNA-17-3p inhibition mice had a higher IDD grade compared with circRNA_104670 inhibition mice (p < 0.05). CircRNA_104670 is highly expressed in the NP tissues of IDD and acts as a ceRNA during NP degradation.

[Comparison of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle puncture: in vitro experiment on a cadaveric lumbar trunk specimen].

OBJECTIVE: To compare the accuracy and operating features of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle punctures. METHODS: A specimen of cadaveric lumbar trunk underwent lumbar pedicle punctures at the levels of L3, L4, and L5 under the guidance of the 3D C-arm fluoroscopy-based and CT-based navigation systems. During the procedure C-arm fluoroscopy was used to monitor the accuracy of the puncture. Generally, in comparison with the 3D C-arm fluoroscopy-based navigation system, the best operation route and protocol could be drawn up pre-operatively, matched registration needed to be renewed for each vertebra, and the images thus obtained were of high quality in CT-based navigation. RESULTS: Both navigation systems had excellent accuracy in the guidance of lumbar pedicle punctures, and had different operating features. CONCLUSION: Both navigation systems had its special advantages. The operating process of the 3D C-arm fluoroscopy-based navigation system was more convenient and rapid, and suitable for percutaneous vertebral puncture. CT based navigation system had clearer pictures, especially for the osteoporotic vertebral bodies, and it had less requirements for the equipments.

[Appraise operative outcome for acute central cervical spinal cord injuries without fracture and dislocation].

OBJECTIVE: To evaluate the surgical outcome for acute central cervical spinal cord injuries without fracture and dislocation. METHODS: A retrospective study was performed on 52 patients with acute central cervical cord injuries without fracture and dislocation from 2000 to 2005. All of patients underwent cervical anterior or posterior decompression, fusion and inter fixation. Spinal function was evaluated by ASIA (American Spinal Injury Association) guidelines. Pre- and post-operation ASIA scores were analyzed using liner correlation and regression. The neurological function was recorded during followed-up. The average follow-up was 29 months (range, 12 to 42). RESULTS: After operation, the ASIA scores increased significantly (P<0.01). Finally, ASIA motor, pin pricking and light touching scores of the 41 patients were 91 +/- 7, 107 +/- 6 and 107 +/- 6 respectively. CONCLUSION: Decompression and inter fixation for injured segment can make a stable and broad space for spinal cord, promoting early neurological recovery and long-term improvement.

Risk Factors for Surgical Results of Hirayama Disease: A Retrospective Analysis of a Large Cohort.

OBJECTIVE: To explore risk factors affecting surgical results of Hirayama disease. METHODS: A retrospective analysis of 210 patients was performed to identify risk factors affecting surgical results of Hirayama disease by using univariate and multivariate analyses. A receiver operating characteristic curve and area under the curve were applied to evaluate the significant results of the multivariate analysis and the optimal reference value. RESULTS: The mean follow-up period was 27.3 months (range, 14-45 months), and 194 patients with clinical and radiographic data completed the final follow-up. Multivariate analysis identified age of patients (cutoff value 22.5 years), duration of the disease (cutoff value 33 months), physiologic reflex, and pathologic reflex as independent risk factors for surgical results of Hirayama disease. The receiver operating characteristic curve analysis and area under the curve showed that good reference value was obtained for the risk factors. CONCLUSIONS: Age of patient, duration of the disease, physiologic reflex, and pathologic reflex are the main risk factors affecting surgical results of Hirayama disease. Receiver operating characteristic analysis shows that good reference value was obtained for the risk factors.

The value of radiographic indexes in the diagnosis of discogenic low back pain: a retrospective analysis of imaging results.

To explore value of different radiographic indexes in the diagnosis of discogenic low back pain (LBP). A total number of 120 cases (60 patients diagnosed with discogenic LBP and 60 healthy people) were retrospectively analysed to identify factors in the diagnosis of discogenic LBP by using univariate and multivariate analyses. A receiver operating characteristic (ROC) curve was drew to show the predictive accuracy of the finally enrolled factors. Among all the included patients, 60 were strictly admitted in the discogenic LBP group while the other 60 were enrolled in the control group. Five results shows significant differences between discogenic LBP and control groups, including Cobb angle, lumbar stability, height of the disc, Modic change and High intense zone (HIZ) based on the results of univariate analysis; lumbar stability, Modic change and HIZ show high value in the diagnosis of lumbar discogenic pain based on the multivariate logistic analysis. The ROC curve shows that good diagnostic accuracy was obtained from the enrolled diagnostic factors including lumbar stability (Angular motion, more than 14.35°), Modic change and HIZ.

[Transduction of recombinant marrow stem cells using lentiviral vector and adenoviral vector: a comparative study].

OBJECTIVE: To compare the efficiency of transfection of marrow stem cells (MSCs) by using lentiviral vector and adenoviral vector. METHODS: MSCs were obtained from the femur bone marrow of rat and cultured. Recombinant plasmid pHIV-CS-CG-PRE containing green fluorescent protein (GFP) gene, and package plasmids pRSV-Rev, pMDLg/pPRE, and pMD.G were infected into the human embryonic kidney cells of the line 293T. The rat MSCs were transfected with the DFP recombinant lentiviral particles, and flow cytometry was used to detect the expression of GFP 1, 3, and 5 weeks later. Full-length human bone morphogenetic protein = 2 (hBMP2) gene was searched out from the GenBank and isolated from human liver cDNA from a sample of liver tissue resected from a patient with liver rupture and then cloned. Thus the lentiviral vector with BMP-2 gene, pHIV-CS-CDF-CG-PRE-BMP-2 was constructed and transfected into 293 cells. Indirect immunofluorescence assay, ELISA, and Western blotting were used to detect the expression of hBMP2 gene. RESULTS: After infected by the viral vectors the GFP expression was significantly better in the lentiviral vector-infected rMSCs than in the adenoviral vector-infected ones. FCM showed that the GFP expression rates of the lentiviral vector-infected rMSCs 1, 3, and 5 weeks after the infection were 90%, 83.2%, and 79% respectively, and he GFP expression rates of the adenoviral vector-infected rMSCs 1, 3, and 5 weeks after the infection were 71%, 0.13%, and 0.05% respectively, all significantly lower than on the former group. Indirect immunofluorescence assay, ELISA, and Western blotting showed that the recombinant lentivirus successfully expressed the target protein in the transfected 293T cells. CONCLUSION: Lentiviral vector with hBMP2 gene can be constructed successfully. The transfection efficiency of BMP2 gene by lentivirus is significantly higher than that of adenovirus.

Can an Endplate-conformed Cervical Cage Provide a Better Biomechanical Environment than a Typical Non-conformed Cage?: A Finite Element Model and Cadaver Study.

OBJECTIVES: To evaluate the biomechanical characteristics of endplate-conformed cervical cages by finite element method (FEM) analysis and cadaver study. METHODS: Twelve specimens (C2 -C7 ) and a finite element model (C3 -C7 ) were subjected to biomechanical evaluations. In the cadaver study, specimens were randomly assigned to intact (I), endplate-conformed (C) and non-conformed (N) groups with C4-5 discs as the treated segments. The morphologies of the endplate-conformed cages were individualized according to CT images of group C and the cages fabricated with a 3-D printer. The non-conformed cages were wedge-shaped and similar to commercially available grafts. Axial pre-compression loads of 73.6 N and moment of 1.8 Nm were used to simulate flexion (FLE), extension (EXT), lateral bending (LB) and axial rotation (AR). Range of motion (ROM) at C4-5 of each specimen was recorded and film sensors fixed between the cages and C5 superior endplates were used to detect interface stress. A finite element model was built based on the CT data of a healthy male volunteer. The morphologies of the endplate-conformed and wedge-shaped, non-conformed cervical cages were both simulated by a reverse engineering technique and implanted at the segment of C4-5 in the finite element model for biomechanical evaluation. Force loading and grouping were similar to those applied in the cadaver study. ROM of C4-5 in group I were recorded to validate the finite element model. Additionally, maximum cage-endplate interface stresses, stress distribution contours on adjoining endplates, intra-disc stresses and facet loadings at adjacent segments were measured and compared between groups. RESULTS: In the cadaver study, Group C showed a much lower interface stress in all directions of motion (all P < 0.05) and the ROM of C4-5 was smaller in FLE-EXT (P = 0.001) but larger in AR (P = 0.017). FEM analysis produced similar results: the model implanted with an endplate-conformed cage presented a lower interface stress with a more uniform stress distribution than that implanted with a non-conformed cage. Additionally, intra-disc stress and facet loading at the adjacent segments were obviously increased in both groups C and N, especially those at the supra-jacent segments. However, stress increase was milder in group C than in group N for all directions of motion. CONCLUSIONS: Endplate-conformed cages can decrease cage-endplate interface stress in all directions of motion and increase cervical stability in FLE-EXT. Additionally, adjacent segments are possibly protected because intra-disc stress and facet loading are smaller after endplate-conformed cage implantation. However, axial stability was reduced in group C, indicating that endplate-conformed cage should not be used alone and an anterior plate system is still important in anterior cervical discectomy and fusion.

Mast Quadrant-assisted minimally invasive modified transforaminal lumbar interbody fusion: single incision versus double incision.

BACKGROUND: The concept of minimally invasive techniques is to make every effort to reduce tissue damage. Certainly, reducing skin incision is an important part of these techniques. This study aimed to investigate the clinical feasibility of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF) with a small single posterior median incision. METHODS: During the period of March 2011 to March 2012, 34 patients with single-segment degenerative lumbar disease underwent the minimally invasive modified TLIF assisted by Mast Quadrant with a small single posterior median incision (single incision group). The cases in this group were compared to 37 patients with single-segment degenerative lumbar disease in the double incision group. The perioperative conditions of patients in these two groups were statistically analyzed and compared. The Oswestry Disability Index (ODI) scores, Visual Analog Scale (VAS) scores, and sacrospinalis muscle damage evaluation indicators before operation and 3, 12 months postoperation were compared. RESULTS: A total of 31 and 35 cases in the single incision and double incision groups, respectively, completed at least 12 months of systemic follow-up. The differences in perioperative conditions between the two groups were not statistically significant. The incision length of the single incision group was significantly shorter than that of the double incision group (P < 0.01). The ODI and VAS scores of patients in both groups improved significantly at 3 and 12 months postoperation. However, these two indicators at 3 and 12 months postoperation and the sacrospinalis muscle damage evaluation indicators at 3 months postoperation did not differ significantly between the two groups (P ≥ 0.05). CONCLUSIONS: Mast Quadrant-assisted modified TLIF with a small single posterior median incision has excellent clinical feasibility compared to minimally invasive TLIF with a double paramedian incision.