Haopeng Li

The incidence of adjacent segment degeneration after cervical disc arthroplasty (CDA): a meta analysis of randomized controlled trials.

Background Cervical disc arthroplasty is being used as an alternative degenerative disc disease treatment with fusion of the cervical spine in order to preserve motion. However, whether replacement arthoplasty in the spine achieves its primary patient centered objective of lowering the frequency of adjacent segment degeneration is not verified yet. Methodology We conducted a meta-analysis according to the guidelines of the Cochrane Collaboration using databases including PubMed, Cochrane Central Register of Controlled Trials and Embase. The inclusion criteria were: 1) Randomized, controlled study of degenerative disc disease of the cervical spine involving single segment or double segments using Cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion (ACDF) as controls; 2) A minimum of two-year follow-up using imaging and clinical analyses; 3) Definite diagnostic evidences for “adjacent segment degeneration” and “adjacent segment disease”; 4) At least a minimum of 30 patients per population. Two authors independently selected trials; assessed methodological quality, extracted data and the results were pooled. Results No study has specifically compared the results of adjacent segment degenerative; Two papers describing 140 patients with 162 symptomatic cervical segment disorders and compared the rate of postoperative adjacent segment disease development between CDA and ACDF treatments, three publications describing the rate of adjacent-segment surgery including 1273 patients with symptomatic cervical segments. The result of the meta-analysis indicates that there were fewer the rate of adjacent segment disease and the rate for adjacent-segment surgery comparing CDA with ACDF, but the difference was not statistically significant. Conclusions Based on available evidence, it cannot be concluded, that CDA can significantly reduce the postoperative rate of the adjacent segment degenerative and adjacent segment disease. However, due to some limitations, the results of this meta-analysis should be cautiously accepted, and further studies are needed.

Systematic Review and Meta-Analysis of Perioperative Intravenous Tranexamic Acid Use in Spinal Surgery

Background Tranexamic acid (TXA) is well-established as a versatile oral, intramuscular, and intravenous (IV) antifibrinolytic agent. However, the efficacy of IV TXA in reducing perioperative blood transfusion in spinal surgery is poorly documented. Methodology We conducted a meta-analysis of randomized controlled trials (RCTs) and quasi-randomized (qi-RCTs) trials that included patients for various spinal surgeries, such as adolescent scoliosis surgery administered with perioperative IV TXA according to Cochrane Collaboration guidelines using electronic PubMed, Cochrane Central Register of Controlled Trials, and Embase databases. Additional journal articles and conference proceedings were manually located by two independent researchers. Results Totally, nine studies were included, with a total sample size of 581 patients. Mean blood loss was decreased in patients treated with perioperative IV TXA by 128.28 ml intraoperatively (ranging from 33.84 to 222.73 ml), 98.49 ml postoperatively (ranging from 83.22 to 113.77 ml), and 389.21 ml combined (ranging from 177.83 to 600.60 ml). The mean volume of transfused packed cells were reduced by 134.55 ml (ranging 51.64 to 217.46) (95% CI; P = 0.0001). Overall, the number of patients treated with TXA who required blood transfusions was lower by 35% than that of patients treated with the comparator and who required blood transfusions (RR 0.65; 95% CI; 0.53 to 0.85; P<0.0001, I2 = 0%). A dose-independent beneficial effect of TXA was observed, and confirmed in subgroup and sensitivity analyses. A total of seven studies reported DVT data. The study containing only a single DVT case was not combined. Conclusions The blood loss was reduced in spinal surgery patients with perioperative IV TXA treatment. Also the percentage of spinal surgery patients who required blood transfusion was significantly decreased. Further evaluation is required to confirm our findings before TXA can be safely used in patients undergoing spine surgery.

Combined Elevation of microRNA-196a and microRNA-196b in Sera Predicts Unfavorable Prognosis in Patients with Osteosarcomas

Aim To investigate whether the aberrant expression of microRNA (miR)-196a and miR-196b can be used as potential prognostic markers of human osteosarcoma. Methods Quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis was performed to detect the expression levels of miR-196a and miR-196b in osteosarcoma tissues and patients’ sera. Results Expression levels of miR-196a and miR-196b in osteosarcoma tissues were both significantly higher than those in noncancerous bone tissues (both p < 0.001), in line with which, the serum levels of the two miRNAs were also markedly upregulated in patients with osteosarcomas compared with healthy controls (both p < 0.001). Then, the elevation of serum miR-196a and miR-196b levels both more frequently occurred in osteosarcoma patients with high tumor grade (p = 0.008 and 0.01, respectively), positive metastasis (p = 0.001 and 0.006, respectively) and recurrence (p = 0.001 and 0.006, respectively). Moreover, high serum miR-196a, high serum miR-196b and conjoined expression of miR-196a/miR-196b were all independent prognostic factors for OS (overall survival) and DFS (disease-free survival) of osteosarcoma patients. Conclusion Our present data indicate the involvement of miR-196a and miR-196b upregulation in the pathogenesis of osteosarcoma. More importantly, the altered levels of circulating miR-196a and miR-196b might have great potential to serve as novel and non-invasive prognostic factors for this malignancy.

Classification of gluteal muscle contracture in children and outcome of different treatments

BackgroundGluteal muscle contracture (GMC) is a clinical syndrome due to multiple etiologies in which hip movements may be severely limited. The aim of this study was to propose a detailed classification of GMC and evaluate the statistical association between outcomes of different management and patient conditions.MethodsOne hundred fifty-eight patients, who were treated between January 1995 and December 2004, were reviewed at a mean duration of follow-up of 4.8 years. Statistical analyses were performed using X2 and Fishers exact tests.ResultsNon-operative management (NOM), as a primary treatment, was effective in 19 of 49 patients (38.8%), while operative management was effective in all 129 patients, with an excellence rating of 83.7% (108/129). The outcome of NOM in level I patients was significantly higher than in level II and III patients (P < 0.05). The results of NOM and operative management in the child group were better than the adolescent group (P < 0.05). Complications in level III were more than in level II.ConclusionNOM was more effective in level I patients than in level II and III patients. Operative management was effective in patients at all levels, with no statistical differences between levels or types. We recommend NOM as primary treatment for level I patients and operative management for level II and III patients. Either NOM or operative management should be carried out as early as possible.

Biomechanical study of anterior cervical corpectomy and step-cut grafting with bioabsorbable screws fixation in cadaveric cervical spine model.

Study Design. An in vitro biomechanical study. Objective. To determine the initial stability of a novel construct in a 1-level cadaveric cervical spine model by comparing it with a conventional method. Summary of Background Data. Lots of endeavors have been made to enhance fusion rates and reduce complications in the anterior cervical spine procedure. Methods. There were 12 fresh human cadaveric cervical spines (C3–C7) randomly divided into 2 groups: group 1, 1-level corpectomy of C5 and step-cut grafting with bioabsorbable screw fixation (SCAS); and group 2, 1-level corpectomy of C5 and strut grafting with anterior plate fixation (SP). For each specimen, the intact underwent a flexibility test first, followed by the instrumented construct. Rotational angles of the C4–C6 segment were measured to study the immediate stability of anterior cervical corpectomy and SCAS, compared with the intact and anterior cervical corpectomy and SP. Results. Both anterior cervical corpectomy with SCAS and with SP significantly (P < 0.01) decreased the motions of C4–C6 in all 6 degrees of freedom after instrumentation. Compared with anterior cervical corpectomy and SP, anterior cervical corpectomy and SCAS had higher stability (P < 0.05) in extension, and comparable stability (P > 0.05) in flexion and axial rotation, but lower stability (P ≤ 0.05) in lateral bending. Conclusion. Anterior cervical corpectomy and SCAS, a novel method of anterior cervical spine decompression and reconstruction, was introduced. The in vitro biomechanical study showed that anterior cervical corpectomy and SCAS had sufficient immediate stability except for the lateral bending, compared with anterior cervical corpectomy and SP, in a 1-level cadaveric cervical spine model. However, an animal experimental in vivo evaluation of anterior cervical corpectomy and SCAS still has to be performed.

miRNA-449a is downregulated in osteosarcoma and promotes cell apoptosis by targeting BCL2

Accumulating evidence reveals that miR-449a is expressed at a low level in several tumors and cancer cell lines, and acts as a tumor suppressor in several cancers. However, its role in osteosarcoma (OS) is not well understood. In the present study, we found that miR-449a was significantly downregulated in both OS tissues and cell lines. Furthermore, low expression level of miR-449a was correlated with advanced tumor stage, metastasis, and predicted a poor overall survival in OS patients. Additionally, restoration of miR-449a in OS cell lines U2OS and Saos-2 reduced cell viability, promoted cell apoptosis in vitro, and suppressed tumorigenicity in vivo. Moreover, BCL2, an antiapoptotic molecule, was identified to be a direct target of miR-449a, and the proapoptotic function of miR-449a was mainly through targeting BCL2 expression. Taken together, our results demonstrated a tumor-suppressive role of miR-449a in OS progression and suggested a potential therapeutic target for OS.

Biomechanical study of artificial atlanto-odontoid joint.

Study Design. An in vitro biomechanical study. Objective. To determine the initial stability and function of a new artificial joint in a cadaveric cervical spine model by comparing it with a conventional method. Summary of Background Data. Resection of the odontoid and anterior arch of the atlas results in atlantoaxial instability, which if left uncorrected may lead to severe neurologic complications. Currently, such atlantoaxial instability is corrected by anterior and/or posterior C1–C2 fusion. Methods. There were 24 fresh human cadaveric cervical spines (C0–C3) randomly divided into 2 groups: group 1, resection of the odontoid with artificial atlanto-odontoid joint (AAOJ); and group 2, resection of the odontoid with Harms anterior atlantoaxial plate (Harms). For each specimen, the intact and resection of the odontoid underwent a flexibility test first, followed by the instrumented construct. Rotational angles of the C0–C3 segment were measured to study the immediate stability and function of resection of the odontoid and AAOJ, compared with the intact and resection of the odontoid and Harms. Results. Compared with the intact state, resection of the odontoid and AAOJ resulted in a significant decrease in the range of motion (ROM) and neutral zone during flexion, extension, and lateral bending (P < 0.05); however, with regard to axial rotation, there was no significant difference in ROM (P > 0.05). Compared with resection of the odontoid and Harms, resection of the odontoid and AAOJ during flexion, extension, and lateral bending, there was no significant difference in ROM (P > 0.05). Conclusion. We have designed a new type of AAOJ for correcting atlantoaxial instability arising from C1 to C2 anterior decompression procedures. The unique aspect of this joint is that it restores, to a great extent, the C1–C2 axial rotation that is lost during current stabilization procedures.

Increased expression of collagens, transforming growth factor-β1, and -β3 in gluteal muscle contracture

BackgroudGluteal muscle contracture (GMC) is a multi-factor human chronic fibrotic disease of the gluteal muscle. Fibrotic tissue is characterized by excessive accumulation of collagen in the muscles extracellular matrix. Transforming growth factor (TGF)-β1 and -β2 are thought to play an important role in fibrogenesis, while TGF-β3 is believed to have an anti-fibrotic function. We hypothesize that the expression of collagen and TGF-βs would be up-regulated in GMC patients.MethodsThe expression of collagen type I, type III and TGF-βs were studied in 23 fibrotic samples and 23 normal/control samples in GMC patients using immunohistochemistry, reverse transcription and polymerase chain reaction (RT-PCR) and western bolt analysis.ResultsCompared to the unaffected adjacent muscle, increased expression of TGF-β1 and -β3 was associated with deposition of collagen type I and type III in the fibrotic muscle of the GMC patients at the mRNA level. Strong up-regulation of these proteins in fibrotic muscle was confirmed by immunohistochemical staining and western blot analysis. TGF-β2 was not up-regulated in relation to GMC.ConclusionThis study confirmed our hypothesis that collagen types I, III, TGF-β1 and TGF-β3 were up-regulated in biopsy specimens obtained from patients with GMC. Complex interaction of TGF-β1 with profibrotic function and TGF-β3 with antifibrotic function may increase synthesis of collagens and thereby significantly contribute to the process of gluteal muscle scarring in patients with GMC.

Clinical efficacy of posterior versus anterior instrumentation for the treatment of spinal tuberculosis in adults: a meta-analysis.

BackgroundThe aim of our study was to evaluate the clinical efficacy of posterior vs. anterior instrumentation for the treatment of spinal tuberculosis in adults.MethodsThe electronic databases such as PubMed, MEDLINE, Springer, EMBASE, Google scholar, and Cochrane library were searched to select the potentially relevant reports that compared the efficacy of posterior instrumentation group (group A) with anterior instrumentation group (group B) in the treatment of spinal tuberculosis. Outcome assessments were correction of angle, loss of correction, fusion rate of the grafting bone, and complications after surgery.ResultsThis meta-analysis included four trials published between 2006 and 2012, involving 291 adult patients (group A, 154; group B, 137) with spinal tuberculosis. The overall meta-analysis showed that there were no significant differences (P > 0.01) between group A and group B in correction of angle and loss of correction at final follow-up after operation The pooled WMD (weighted mean difference) of group A and group B was 2.85 (95% CI (confidence interval) = -1.25 ~ 6.94) and 1.14 (95% CI = -3.07 ~ 5.34), respectively. Besides, no significant differences (P > 0.01) were observed in fusion rate of the grafting bone and complications after operation between group A and group B, and the pooled ORs (odds ratio) were 0.65 (95% CI = -0.23 ~ 1.85) and (95% CI = -0.19 ~ 1.50), respectively.ConclusionsOur results suggested that the posterior instrumentation appeared to have the same clinical outcome with the anterior instrumentation in the treatment of the adult patients with spinal tuberculosis.

Artificial Cervical Vertebra and Intervertebral Complex Replacement through the Anterior Approach in Animal Model: A Biomechanical and In Vivo Evaluation of a Successful Goat Model

This was an in vitro and in vivo study to develop a novel artificial cervical vertebra and intervertebral complex (ACVC) joint in a goat model to provide a new method for treating degenerative disc disease in the cervical spine. The objectives of this study were to test the safety, validity, and effectiveness of ACVC by goat model and to provide preclinical data for a clinical trial in humans in future. We designed the ACVC based on the radiological and anatomical data on goat and human cervical spines, established an animal model by implanting the ACVC into goat cervical spines in vitro prior to in vivo implantation through the anterior approach, and evaluated clinical, radiological, biomechanical parameters after implantation. The X-ray radiological data revealed similarities between goat and human intervertebral angles at the levels of C2-3, C3-4, and C4-5, and between goat and human lordosis angles at the levels of C3-4 and C4-5. In the in vivo implantation, the goats successfully endured the entire experimental procedure and recovered well after the surgery. The radiological results showed that there was no dislocation of the ACVC and that the ACVC successfully restored the intervertebral disc height after the surgery. The biomechanical data showed that there was no significant difference in range of motion (ROM) or neural zone (NZ) between the control group and the ACVC group in flexion-extension and lateral bending before or after the fatigue test. The ROM and NZ of the ACVC group were greater than those of the control group for rotation. In conclusion, the goat provides an excellent animal model for the biomechanical study of the cervical spine. The ACVC is able to provide instant stability after surgery and to preserve normal motion in the cervical spine.