Correction to: microRNA-124 inhibits bone metastasis of breast cancer by repressing Interleukin-11.

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microRNA-124 inhibits bone metastasis of breast cancer by repressing Interleukin-11.

BACKGROUND: Most patients with breast cancer in advanced stages of the disease suffer from bone metastases which lead to fractures and nerve compression syndromes. microRNA dysregulation is an important event in the metastases of breast cancer to bone. microRNA-124 (miR-124) has been proved to inhibit cancer progression, whereas its effect on bone metastases of breast cancer has not been reported. Therefore, this study aimed to investigate the role and underlying mechanism of miR-124 in bone metastases of breast cancer. METHODS: In situ hybridization (ISH) was used to detect the expression of miR-124 in breast cancer tissues and bone metastatic tissues. Ventricle injection model was constructed to explore the effect of miR-124 on bone metastasis in vivo. The function of cancer cell derived miR-124 in the differentiation of osteoclast progenitor cells was verified in vitro. Dual-luciferase reporter assay was conducted to confirm Interleukin-11 (IL-11) as a miR-124 target. The involvement of miR-124/IL-11 in the prognosis of breast cancer patients with bone metastasis was determined by Kaplan-Meier analysis. RESULTS: Herein, we found that miR-124 was significantly reduced in metastatic bone tissues from breast cancers. Down-regulation of miR-124 was associated with aggressive clinical characteristics and shorter bone metastasis-free survival and overall survival. Restoration of miR-124 suppressed, while inhibition of miR-124 promoted the bone metastasis of breast cancer cells in vivo. At the cellular level, gain of function and loss-of function assays indicated that cancer cell-derived miR-124 inhibited the survival and differentiation of osteoclast progenitor cells. At the molecular level, we demonstrated that IL-11 partially mediated osteoclastogenesis suppression by miR-124 using in vitro and in vivo assays. Furthermore, IL-11 levels were inversely correlated with miR-124, and up-regulation IL-11 in bone metastases was associated with a poor prognosis. CONCLUSIONS: Thus, the identification of a dysregulated miR-124/IL-11 axis helps elucidate mechanisms of breast cancer metastases to bone, uncovers new prognostic markers, and facilitates the development of novel therapeutic targets to treat and even prevent bone metastases of breast cancer.

HIF1/2α mediates hypoxia-induced LDHA expression in human pancreatic cancer cells.

Glycolysis is a typical conduit for energy metabolism in pancreatic cancer (PC) due to the hypoxic microenviroment. Lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactate and is considered to be a key checkpoint of anaerobic glycolysis. The aim of the present study was to explore the mechanism of interactions between hypoxia, HIF-1/2α and LDHA, and the function of LDHA on PC cells by analyzing 244 PC and paratumor specimens. It was found that LDHA was over-expressed and related to tumor stages. The result of in vitro study demonstrated that hypoxia induced LDHA expression. To explore the relationship between HIF and LDHA, chromatin immunoprecipitation assay and luciferase assay were performed. The result showed that HIF-1/2α bound to LDHA at 89bp under the hypoxic condition. Furthermore, knockdown of endogenous HIF-1α and HIF-2α decreased the LDHA expression even in the hypoxic condition, which was accompanied with a significant decrease in lactate production and glucose utilization (p < 0.01). Immunofluorescence in the 244 specimens showed that HIF-1/2α was over-expressed and associated with LDHA over-expression (p < 0.0001). Forced expression of LDHA promoted the growth and migration of PC cells, while knocking down the expression of LDHA inhibited the cell growth and migration markedly. In summary, the present study proved that HIF1/2α could activate LDHA expression in human PC cells, and high expression of LDHA promoted the growth and migration of PC cells.

HIF-1α activates hypoxia-induced BCL-9 expression in human colorectal cancer cells.

B-cell CLL/lymphoma 9 protein (BCL-9), a multi-functional co-factor in Wnt signaling, induced carcinogenesis as well as promoting tumor progression, metastasis and chemo-resistance in colorectal cancer (CRC). However, the mechanisms for increased BCL-9 expression in CRC were not well understood. Here, we report that hypoxia, a hallmark of solid tumors, induced BCL-9 mRNA expression in human CRC cells. Analysis of BCL-9 promoter revealed two functional hypoxia-responsive elements (HRE-B and HRE-C) that can be specifically bound with and be transactivated by hypoxia inducible factors (HIF) -1α but not HIF-2α. Consistently, ectopic expression of HIF-1α but not HIF-2α transcriptionally induced BCL-9 expression levels in cells. Knockdown of endogenous HIF-1α but not HIF-2α by siRNA largely abolished the induction of HIF by hypoxia. Furthermore, there was a strong association of HIF-1α expression with BCL-9 expression in human CRC specimens. In summary, results from this study demonstrated that hypoxia induced BCL-9 expression in human CRC cells mainly through HIF-1α, which could be an important underlying mechanism for increased BCL-9 expression in CRC.

En Bloc Resection of Primary Malignant Bone Tumor in the Cervical Spine Based on 3-Dimensional Printing Technology.

OBJECTIVE: To investigate the feasibility and safety of en bloc resection of cervical primary malignant bone tumors by a combined anterior and posterior approach based on a three-dimensional (3-D) printing model. METHODS: Five patients with primary malignant bone tumors of the cervical spine underwent en bloc resection via a one-stage combined anteroposterior approach in our hospital from March 2013 to June 2014. They comprised three men and two women of mean age 47.2 years (range, 26-67 years). Three of the tumors were chondrosarcomas and two chordomas. Preoperative 3-D printing models were created by 3-D printing technology. Sagittal en bloc resections were planned based on these models and successfully performed. A 360° reconstruction was performed by spinal instrumentation in all cases. Surgical margins, perioperative complications, local control rate and survival rate were assessed. RESULTS: All patients underwent en bloc excision via a combined posterior and anterior approach in one stage. Mean operative time and estimated blood loss were 465 minutes and 1290 mL, respectively. Mean follow-up was 21 months. Wide surgical margins were achieved in two patients and marginal resection in three; these three patients underwent postoperative adjuvant radiation therapy. One vertebral artery was ligated and sacrificed in each of three patients. Nerve root involved by tumor was sacrificed in three patients with preoperative upper extremity weakness. One patient (Case 3) had significant transient radiculopathy with paresis postoperatively. Another (Case 4) with C 4 and C 5 chordoma had respiratory difficulties and pneumonia after surgery postoperatively. He recovered completely after 2 weeks' management with a tracheotomy tube and antibiotics in the intensive care unit. No cerebrovascular complications and wound infection were observed. No local recurrence or instrumentation failure were detected during follow-up. CONCLUSION: Though technically challenging, it is feasible and safe to perform en bloc resection of cervical primary bone tumors. This is the most effective means of managing cervical spine tumors. Preoperative 3-D printing modelling enables better anatomical understanding of the relationship between the tumor and cervical spine and can assist in planning the surgical procedure.

MiR-451 inhibits synovial fibroblasts proliferation and inflammatory cytokines secretion in rheumatoid arthritis through mediating p38MAPK signaling pathway.

Rheumatoid arthritis is an autoimmune disease characterized as joint synovial inflammation. MicroRNA is a group of small noncoding RNA molecules discovered in recent years that can posttranscriptional regulate mRNA expression and involved in a variety processes of immune cell activation and differentiation. There is still lack of study about the role of miR-451 in rheumatoid arthritis. Synovial fibroblasts isolated from rheumatoid arthritis patients were cultured in vitro. Chemical synthesized miR-451 was lipo-transfected, real-time RT-PCR was applied to detect miR-451 expression level, and MTT method was used to detect the effect of miR-451 on synovial fibroblasts proliferation. Enzyme-linked immunosorbent assay was used to detect tumor necrosis factor TNF-α, IL-1ß, and IL-6 level in the supernatant. Western blot was applied to test target protein p38 MAPK expression level. Our study found that synovial fibroblasts expressed higher miR-451 mRNA level in miR-451 treatment group. MiR-451 treatment significantly decreased cell proliferation ability (P < 0.05). Compared with the control, p38 MAPK protein expression reduced obviously in the miR-451 treatment group (P < 0.05). MiR-451 transfected synovial fibroblasts secreted lower levels of TNF-α (198 ± 12 pg/ml vs 124 ± 13 pg/ml, P < 0.01), IL-1ß (352 ± 43 pg/ml vs 165 ± 87 pg/ml, P < 0.01), and IL-6 (487 ± 84 pg/ml vs 257 ± 92 pg/ml, P < 0.01). The results proved that miR-451 can down-regulate p38 MAPK protein expression, and reduce synovial fibroblasts proliferation and cytokine expression level.

Knockdown of TNFAIP1 inhibits growth and induces apoptosis in osteosarcoma cells through inhibition of the nuclear factor-κB pathway.

Tumor necrosis factor-α-inducible protein-1 (TNFAIP1) plays a role in DNA synthesis, DNA repair, cell apoptosis and human diseases including cancer, and may be involved in tumor progression and metastases. However, little is known concerning the function of TNFAIP1 in human osteosarcoma (OS). The aim of the present study was to investigate the function and underlying mechanisms of TNFAIP1 in human OS. The expression of TNFAIP1 was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects of lentiviral-mediated TNFAIP1 siRNA (siTNFAIP1) on cell proliferation, invasive potential and apoptosis by MTT and Transwell assays and flow cytometric analysis in OS (MG-63 and U-2 OS) cells. The results showed that the expression of TNFAIP1 protein was significantly increased in OS tissues compared with that in adjacent non-cancerous tissues (ANCTs) (73.3 vs. 48.9%, P=0.018), and was correlated with the distant metastasis of the patients with OS (P=0.029). Knockdown of TNFAIP1 suppressed cell proliferation and invasion, and induced cell apoptosis in the OS cells together with the downregulation of p65 nuclear factor-κB (NF-κB), proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase-2 (MMP-2) and upregulation of caspase-3. Collectively, our findings indicate that high expression of TNFAIP1 is associated with distant metastasis of OS, and knockdown of TNFAIP1 inhibits the growth and invasion, and induces apoptosis in OS cells through inhibition of the NF-κB pathway, suggesting that TNFAIP1 may act as a potential therapeutic target for the treatment of cancer.

[Biomechanical performance of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability].

OBJECTIVE: To compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes. METHODS: Six specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire. RESULTS: The strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05). CONCLUSIONS: The fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

[The surgical treatment of severe adolescent idiopathic cervical kyphosis].

OBJECTIVE: To summarize the clinical characteristics of severe adolescent idiopathic cervical kyphosis and the operation method. METHODS: A retrospective study was performed in 12 adolescent patients with severe cervical kyphosis treated from July 2003 to January 2007. Preoperative the Cobb angle of kyphosis range from 55 degrees to 73 degrees (average 61 degrees ). According to the angles between the posterior vertebral body tangents at every involved level on lateral cervical radiograph in extension, the osteotomy angles and range of lamina and facet were decided. The anterior release and posterior osteotomy were performed firstly. Then skull traction was maintained in order to correct the deformity as long as possible, fusion and internal fixation was completed after 7-10 days. The cervical coronal and sagittal planes X-rays and the MR were hold after operation 3 days, 3 months, 6 months, 1 year and 2 years. At the same time the treatment result, bone fusion and the instrumentation were followed up, and the symptoms were compared between pre-operation and post-operation. RESULTS: The defect appearance of the patients was improved significantly, with the total disappearance of neck pain and improvement of nerve function. Post-operational cervical spine MR showed that the physiological curve of cervical spine was restored, cerebral spinal fluid line was clear in the kyphosis area and no spinal cord compression was found. X-ray imaging of post-operation 3 d showed that Cobb angle ranged from -12.3 degrees to 11.2 degrees with an average of -2.0 degrees . Beside one patient's AISA score was D, other patient's AISA score was E. CONCLUSIONS: The severe adolescent idiopathic cervical kyphosis has its own clinical manifestation. It is an ideal treatment to completely assess the deformity, have staging operation and skull traction between two operations.

Choice of surgical approach for ossification of the posterior longitudinal ligament in combination with cervical disc hernia.

Ossification of the posterior longitudinal ligament (OPLL) is a common spinal disorder that presents with or without cervical myelopathy. Furthermore, there is evidence suggesting that OPLL often coexists with cervical disc hernia (CDH), and that the latter is the more important compression factor. To raise the awareness of CDH in OPLL for spinal surgeons, we performed a retrospective study on 142 patients with radiologically proven OPLL who had received surgery between January 2004 and January 2008 in our hospital. Plain radiograph, three-dimensional computed tomography construction (3D CT), and magnetic resonance imaging (MRI) of the cervical spine were all performed. Twenty-six patients with obvious CDH (15 of segmental-type, nine of mixed-type, two of continuous-type) were selected via clinical and radiographic features, and intraoperative findings. By MRI, the most commonly involved level was C5/6, followed by C3/4, C4/5, and C6/7. The areas of greatest spinal cord compression were at the disc levels because of herniated cervical discs. Eight patients were decompressed via anterior cervical discectomy and fusion (ACDF), 13 patients via anterior cervical corpectomy and fusion (ACCF), and five patients via ACDF combined with posterior laminectomy and fusion. The outcomes were all favorable. In conclusion, surgeons should consider the potential for CDH when performing spinal cord decompression and deciding the surgical approach in patients presenting with OPLL.

[Anterior decompression for the treatment of cervical spondylotic myelopathy associated with ossification of posterior longitudinal ligament].

OBJECTIVE: To study the technique and effect of anterior decompression for the treatment of cervical spondylotic myelopathy associated with ossification of posterior longitudinal ligament (OPLL). METHOD: Sixty-one patients (42 male and 19 female, 45 - 74 years with mean age of 57 years old) underwent anterior decompression for the treatment of cervical spondylotic myelopathy associated with OPLL. Among them, OPLL was definitely diagnosed in 49 patients preoperatively, and was found during the operation in the other 12 patients. The occupying rate of OPLL ranged 32%-70% with an average of 52%. The preoperative JOA scores ranged 4 - 14 points with an average of 9.6 points. In additional to conventional decompression, the ossification was removed completely after discectomy and corpectomy. RESULTS: Corpectomy was performed in 41 cases, discectomy in 6 cases and combination of corpectomy and discectomy in 14 cases. The follow-up of all patients ranged from 6 to 36 months (mean 16 months). The postoperative JOA scores ranged 8-16 points with an average of 12.8 points. The neurological improvement rate ranged from 25.0% to 87.5% with an average of 65.2%. The transient leakage of cerebrospinal fluid (CSF) occurred in 5 cases, and stopped after conservational treatment. No neurological deterioration developed. CONCLUSIONS: The difficulty and risk of anterior decompression are significantly increased in the patients with cervical spondylotic myelopathy associated with OPLL. Remove of ossification after corpectomy and discectomy could provide complete decompression and better results.

[Anterior multilevel corpectomy for the treatment of severe ossification of posterior longitudinal ligament in the cervical spine].

OBJECTIVE: To discuss the surgical indications, outcomes and complications of anterior multilevel corpectomy for the treatment of severe ossification of posterior longitudinal ligament (OPLL) in the cervical spine. METHODS: Between April 2006 and March 2008, a total of 25 patients (20 males and 5 females, age range: 42 - 75 yr, mean: 53. 2 yr) underwent anterior multilevel corpectomy for severe ossification of posterior longitudinal ligament in the cervical spine. Radiological studies showed that the type of OPLL was distributed as follows: 7 local, 5 segmental, 8 continuous and 5 mixed. The OPLL extended an average of 2. 8 vertebrae (2 - 4) and the stenotic rate of spinal canal was 68.4% (50% - 97%). After corpectomy and removal of OPLL, titanium mesh cage and anterior plate were employed to restore cervical stability in all patients. RESULTS: Among these patients, 16 underwent two-level corpectomy and 9 three-level corpectomy. After a follow-up of 2 - 18 months, the mean JOA score increased from 9. 3 (5 - 12) points pre-operation to 14.2 (11 - 16) points post-operation. The mean improvement rate of neurological status was 63.2% (22.2% - 87.5%). The complications included CSF leakage in 6 cases (intermittent CSF pseudocyst in 4), nerve root palsy in 2, hematoma in 1 and transient neurological deterioration in 1. CONCLUSION: Anterior multilevel corpextomy can achieve a better clinical outcome in the treatment of severe cervical ossification of posterior longitudinal ligament. But it is technically demanding and carries a higher risk.

[Anti-rotation biomechanical study of wire and various cable system in the posterior brooks instrumentation for atlantoaxial instability].

OBJECTIVE: To compare the anti-rotation biomechanical performances of wire and various cable fixation devices currently used in the posterior Brooks instrumentation for atlantoaxial instability. METHODS: In this experiment,six specimens of the atlantoaxial complex (Occipital-C3) were used. The models of the normal complex,unstable complex (type II odontoid fracture) and fixed complex were established. On the WD-5 mechanics experimental machine,the parameters including the strength and rigidity of anti-rotation were quantified for the normal complex (group N),the atlantoaxial instability complex (group M), the new type Titanium cable (group A), Atlas titanium cable (group B), Songer Titanium cable (group C), stainless wire(group D). RESULTS: The max strength of A, B, C, D groups was 12.5, 11.3, 11.52, 11.55 N x m respectively, the max rigidity was 58.81, 53.17, 54.11, 54.35 N x cm/deg respectively. The strength and rigidity of anti-rotation, compare to the unstable atlantoaxial complex which were fixed by the new double locking Titanium cable fixation system were superior to those of normal complex, instability complex, Songer or Atlas Titanium cable (P < 0.05). CONCLUSION: Having been changed the locking method, the anti-rotation biomechanical characteristics of the new type double locking Titanium cable fixation system are superior or similar to the traditional Songer or Atlas Titanium cable.

[Clinical characteristics and diagnosis of rheumatoid arthritis of upper cervical spine: analysis of 71 cases].

OBJECTIVE: To study the clinical characteristics and diagnosis of rheumatoid arthritis (RA) in the upper cervical spine. METHODS: The clinical data of 71 patients with RA in the upper cervical spine, 18 males and 53 females, aged 46.2 (23-76), with a mean duration of RA of 18.2 years (2 months-47 years) were retrospectively reviewed. Fifty-three patients received glucocorticoid for more than 3 months. In addition to routine examinations, all patients underwent plain X-ray film taking, CT and MRI scanning, and erythrocyte sedimentation rate, rheumatoid factor (RF) and antistreptolysin O testing. RESULTS: The symptoms of upper cervical spine appeared at 8.3 years (2 months-46 years) after the diagnosis of RA was confirmed. The clinical manifestations of RA in the upper cervical spine were intractable pain in craniocervical junction or radiating pain. Abnormal postures in the neck and Sherp-Purser's sign were positive in some patients. Progressive neurological dysfunction with the involvement of spinal cord, medulla, or some cranial nerves might gradually appear. Irregular destruction of bone with osteoporosis around the lateral and median atlantoaxial joint was a common finding in the X-ray films and CT scans. Instability of the atlantoaxial joint, including anterior atlantoaxial subluxation, posterior atlantoaxial subluxation and anterior-posterior atlantoaxial subluxation were found in 68 cases, while rotation subluxation was presented in 37 cases. Vertical migration of the odontoid was seen in 11 cases. RF was positive in 18 cases. MRI revealed that the cause of spinal cord compression was the bone tissue and soft tissue pannus. CONCLUSIONS: RA in the upper cervical spine is a common situation in the clinical settings. The key point in the diagnosis of this disease is the identification of instability in the atlantoaxial joint and assessment of the spinal neurological deficit. And a careful analysis of the natural history will further help to achieve a better treatment effect.

[Change of motor evoked potential of the diaphragm after graded upper cervical spinal cord injury in rats].

OBJECTIVE: To study the change of motor evoked potential of the diaphragm after graded upper cervical cord injuries and analyze the prognosis of the respiratory function after upper cervical cord injuries by MEP. METHODS: The C(3, 4) spinal cord of 40 SD rats were injured with modified Allen method by weight drop force of 30 gcf, 50 gcf, 80 gcf, 100 gcf. The change of latent and amplitude of MEP of the diaphragm was observed before and after the spinal cord injuries (followed up for 1 month). At the same time, the femoral arterial blood of 0.2 ml was drawn. The pH value, the partial pressure of oxygen, the partial pressure of carbon dioxide, and the saturation of the blood oxygen were monitored. The change of the respiratory function was evaluated in the rats after cervical cord injuries. The relationship between the recovery of the respiratory function and the latent or amplitude was analyzed. RESULTS: The MEP wave of the diaphragm was stable before the upper cervical spinal cord injury in the rats. It was usually composed of a positive and negative wave. The latent period and peak-peak amplitude of wave were (3.13 +/- 0.29) ms and (6.78 +/- 3.48) mv. The latent period of the diaphragms MEP in rats change with graded upper cervical cord injuries significantly, the more sever the injury, the longer the latent period. There were obvious relationship between the change of the latent period and the recovery of the respiratory function. When the latent period prolonged 101%, the respiratory function is hardly to recovery. CONCLUSIONS: MEP can objectively and sensitively reflect the injury extent of the respiratory function when upper cervical cord is injured. It would be a reliable index to evaluate the long-term prognosis of respiratory function.

[The biomechanical study of craniovertebral junction fixation with posterior transarticular screw].

OBJECTIVE: To evaluate the stability of biomechanics of occipitoatlantoaxial reconstruction with transarticular screw fixation. METHODS: Twelve fresh human cadaveric occipitocervical spine specimens were mounted in a custom-designed, spine-testing machine that applied pure moments while recording the three-dimensional angular movement at occiput (Oc)-C(1) and C(1 - 2) segments. The specimens were tested under seven different conditions: the intact (intact group), the occipitoatlantoaxial instability (Destabilized group), fixation with Ti-cable plus bone graft group (cable + graf group), fixation with the transarticular fixation (CTS group), fixation with SUMMIT occitocervical spinal fixation system (SUMMIT group), fixation with transarticular screw plus bone graft (CTS + graf group), and fixation with SMMIT system and plus graft group (SUMMIT + graf group). The data obtained were statistically analyzed. RESULTS: The CTS group reduced motion to well within the normal rang. In the Oc-C(1) segment, The CTS group and SUMMIT group allowed a very small rang of motion (ROM) and neutral zone (NZ) during lateral bending and axial rotation. The ROM and NZ during flexion and extension of the SUMMIT group, were significantly smaller than those of cable + graf group and CTS group (6.64 degrees +/- 0.59 degrees, 2.49 degrees +/- 0.26 degrees, 0.50 degrees +/- 0.03 degrees, 0.21 degrees +/- 0.01 degrees, 0.27 degrees +/- 0.07 degrees, 0.13 degrees +/- 0.01 degrees vs 10.01 degrees +/- 1.26 degrees, 3.80 degrees +/- 0.79 degrees, 7.93 degrees +/- 1.34 degrees, 3.18 degrees +/- 0.95 degrees, 9.54 degrees +/- 0.87 degrees, 5.93 degrees +/- 0.74 degrees, P < 0.05). In the C(1 - 2) segment, ROM and NZ in all directions of CTS group were smaller in rotation than SUMMIT group (1.64 degrees +/- 0.39 degrees, 0.61 degrees +/- 0.15 degrees, 0.14 degrees +/- 0.05 degrees, 0.02 degrees +/- 0.01 degrees, 0.32 degrees +/- 0.04 degrees, 0.08 degrees +/- 0.01 degrees, vs 0.21 degrees +/- 0.04 degrees, 0.07 degrees +/- 0.03 degrees, 0.21 degrees +/- 0.12 degrees, 0.10 degrees +/- 0.02 degrees, 2.92 degrees +/- 0.28 degrees, 1.27 degrees +/- 0.11 degrees, all P < 0.05). There was no significant difference in ROM and NZ in all directions between CTS + graf group and SUMMIT + Graf group (P > 0.05). CONCLUSION: In vivo biomechanics studies show that posterior occipitocervical transarticular fixation has unique features in reconstructing dynamic stability of the occipitoatlantoaxis, especially in controlling stability of rotation and lateral flexion, thus ensuring successful fusion of the implanted bone and allowing for clinical use of the technique.