Biomechanical evaluation of a novel atlas polyaxial transverse connecting screw system, an in vitro human cadaveric study.

PURPOSE: To introduce a novel transverse connecting screw system, and to evaluate the biomechanical stability of the novel screw system using human cadaveric specimens. METHODS: Six fresh-frozen cadaveric upper cervical spines were used in our study. Every specimen was tested under 5 conditions: intact group; unstable group; C1 to C2 screw rod system group; C1 to C2 + crosslink system group; atlas polyaxial transverse connecting screw (APTCS) system. RESULTS: Compared with the intact state, C1 to C2 screw rod system, C1 to C2 + CL system and APTCS showed statistically decrease range of motion in all directions except for the unstable group under posterior extension direction (P < .05). APTCS group has the least range of motion in all directions (P < .001). CONCLUSION: The APTCS system was able to restore stability to the atlantoaxial joint. APTCS system has the advantages of easy installation, convenient bone grafting, and strong biomechanical strength.

Combined TIM-3 and PD-1 blockade restrains hepatocellular carcinoma development by facilitating CD4+ and CD8+ T cell-mediated antitumor immune responses.

BACKGROUND: Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) and T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) are beneficial to the resumption of anti-tumor immunity response and hold extreme potential as efficient therapies for certain malignancies. However, ICIs with a single target exhibit poor overall response rate in hepatocellular carcinoma (HCC) patients due to the complex pathological mechanisms of HCC. AIM: To investigate the effects of combined TIM-3 and PD-1 blockade on tumor development in an HCC mouse model, aiming to identify more effective immunotherapies and provide more treatment options for HCC patients. METHODS: The levels of PD-1 and TIM-3 on CD4+ and CD8+ T cells from tumor tissues, ascites, and matched adjacent tissues from HCC patients were determined with flow cytometry. An HCC xenograft mouse model was established and treated with anti-TIM-3 monoclonal antibody (mAb) and/or anti-PD-1 mAb. Tumor growth in each group was measured. Hematoxylin and eosin staining and immunohistochemical staining were used to evaluate T cell infiltration in tumors. The percentage of CD4+ and CD8+ T cells in tissue samples from mice was tested with flow cytometry. The percentages of PD-1+CD8+, TIM-3+CD8+, and PD-1+TIM-3+ CD8+ T cells was accessed by flow cytometry. The levels of the cytokines including tumor necrosis factor alpha (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-6, and IL-10 in tumor tissues were gauged with enzyme-linked immunosorbent assay kits. RESULTS: We confirmed that PD-1 and TIM-3 expression was substantially upregulated in CD4+ and CD8+ T cells isolated from tumor tissues and ascites of HCC patients. TIM-3 mAb and PD-1 mAb treatment both reduced tumor volume and weight, while combined blockade had more substantial anti-tumor effects than individual treatment. Then we showed that combined therapy increased T cell infiltration into tumor tissues, and downregulated PD-1 and TIM-3 expression on CD8+ T cells in tumor tissues. Moreover, combined treatment facilitated the production of T cell effector cytokines TNF-α and IFN-γ, and reduced the production of immunosuppressive cytokines IL-10 and IL-6 in tumor tissues. Thus, we implicated that combined blockade could ameliorate T cell exhaustion in HCC mouse model. CONCLUSION: Combined TIM-3 and PD-1 blockade restrains HCC development by facilitating CD4+ and CD8+ T cell-mediated antitumor immune responses.

[Imaging measurement for the posterior pars interarticularis screw fixation on axis].

OBJECTIVE: To explore the safety and feasibility of posterior pars interarticularis screw fixation on axis by CT measurement. METHODS: The CT data of 137 patients with complete upper cervical spine who underwent full cervical spine CT examination from January 2016 to December 2019 were collected, including 71 males and 66 females, aged from 22 to 65 years old with an average of (41.8±17.4) years old. Mimics 19.0 software was used to measure anatomical data related to the pars interarticularis screw, including the pars width, pars vertical length, pars vertical height, length of pars screw trajectory, upward inclination angle of pars screw trajectory. And the correlation between each index was analyzed. RESULTS: The axis pars has an average width of (9.05±1.63) mm, an average vertical length of (11.21±1.43) mm, and an average vertical height of (17.53±2.93) mm. The mean length of pars screw trajectory was(19.07±3.20) mm. Regarding to the length of pars screw trajectory, 94.53% of pars measured more than 14 mm, 82.12% of pars measured at 14-16 mm, 63.14% of pars measured at 16-18 mm, 39.78% of pars measured at 18-20 mm. The upward inclination angle of pars screw was 30°-68° with an average of (46.06±8.06) °. There was a highly positive correlation between the length of screw trajectory and upward inclination angle(r=0.965, P=0.000). The vertical length of pars was weakly positively correlated with length of screw trajectory and upward inclination angle(r=0.240, P=0.000;r=0.163, P=0.007). Pars width was moderately negative correlated with length of scrwe trajectory and upward inclination angle(r =-0.333, P=0.000;r=-0.380, P=0.000). CONCLUSION: The posterior pars interarticularis screw fixation is safe and reliable. It has a more wider applicability than pedicle screw fixation and can be used as an alternative to pedicle screws.

Posterior temporary fixation of C1-C2 screw-rod system for unstable C1 burst fracture.

Whether an unstable C1 burst fracture should be treated surgically or conservatively is controversial. The purpose of this study is to evaluate the effectiveness and motion-preserving function of temporary fixation of C1-C2 screw-rod system for the reduction and fixation of unstable C1 burst fracture. We retrospectively reviewed 10 patients who were treated with posterior C1-C2 temporary fixation without fusion. We assessed age at surgery, gender, pre- and postoperative visual analog scale (VAS), Neck Disability Index (NDI), atlanto-dens interval (ADI), lateral mass distance (LMD), and rotation function of C1-C2 complex. Six males and 4 females were included in our study. The average follow-up duration was 14.1 ± 1.37 months. The left-to-right ROMs of C1-C2 rotation was 9.6° ± 1.42°. The preoperative cervical VAS was 8.30 ± 0.48; the postoperative cervical VAS of C1-C2 fusion was 2.90 ± 0.57. The preoperative VAS for removal was 2.0 ± 0.00, and the postoperative VAS for removal was 2.3 ± 0.48. The preoperative cervical NDI was 81.40% ± 2.07%, the postoperative cervical NDI of C1-C2 fusion was 18.10% ± 1.52%. The preoperative NDI for removal was 15.9% ± 1.20%. The postoperative NDI for removal was 14.5% ± 1.08%. The preoperative ADI was 4.43 ± 0.34 mm, and postoperative ADI was 1.94 ± 0.72 mm. The preoperative LMD was 6.36 ± 0.58 mm, and postoperative LMD was 1.64 ± 0.31 mm. Posterior temporary C1-C2 fixation can achieve a good fusion and satisfied reduction of C1 fracture, relieve the pain, improve the cervical function outcome, but may reduce the rotational range of motion of C1-C2. Posterior C1-C2 temporary fixation without fusion was not suitable for C1 burst fracture. We recommend permanent C1-C2 fixation and fusion for C1 burst fracture if surgery is necessary.

Contralateral radiculopathy after unilateral transforaminal lumbar interbody fusion: causes and prevention.

BACKGROUND: Unilateral transforminal lumbar interbody fusion (TLIF) with a single cage can provide circumferential fusion and biomechanical stability. However, the causes and prevention of contralateral radiculopathy following unilateral TLIF remain unclear. METHODS: In total, 190 patients who underwent unilateral TLIF from January 2017 to January 2019 were retrospectively reviewed. Radiological parameters including lumbar lordosis, segmental angle, anterior disc height, posterior disc height (PDH), foraminal height (FH), foraminal width, and foraminal area (FA) were measured preoperatively and postoperatively. Preoperative and postoperative visual analog scale scores were also recorded. RESULTS: The incidence of contralateral radiculopathy after unilateral TLIF was 5.3% (10/190). The most common cause was contralateral foraminal stenosis. Unilateral TLIF could increase the lumbar lordosis, segmental angle, and anterior disc height but decrease the PDH, FA, and FH in patients with symptomatic contralateral radiculopathy. The intervertebral cage should be placed to cover the epiphyseal ring and cortical compact bone of the midline, and the disc height can be increased to enlarge the contralateral foramen. CONCLUSION: The most common cause of contralateral radiculopathy is contralateral foraminal stenosis. Careful preoperative planning is necessary to achieve satisfactory outcomes. Improper unilateral TLIF will decrease the PDH, FA, and FH, resulting in contralateral radiculopathy.

[Treatment strategy and curative effect analysis of os odontoideum complicated with atlantoaxial joint dislocation].

OBJECTIVE: To explore the treatment strategy and clinical efficacy for os odontoideum complicated with atlantoaxial dislocation. METHODS: The clinical data of 17 patients with os odontoideum complicated with atlantoaxial dislocation surgically treated from January 2006 to January 2015 were retrospectively analyzed, including 7 males and 10 females, aged 17 to 53 (43.1±11.3) years old;course of disease was 3 to 27(10.2±6.9) months. All patients received cranial traction before operation, 12 of 14 patients with reducible dislocation were treated by posterior atlantoaxial fixation and fusion, and 2 patients with atlantooccipital deformity were treated by posterior occipitocervical fixation and fusion;3 patients with irreducible alantoaxial dislocation were treated by transoral approach decompression combined with posterior atlantoaxial fixation and fusion. The operation time, intraoperative blood loss and perioperative complications were recorded. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the change of neck pain and neurological function. Atlantoaxial joint fusion rate was evaluated by CT scan. RESULTS: The operation time of posterior fixation and fusion ranged from 86 to 170 (92.2±27.5) min, and the intraoperative blood loss was 200-350 (250.7±65.2) ml. No vertebral artery injury and spinal cord injury were recorded. Among the patients underwent atlantoaxial fixation and fusion, 1 patient with reducible dislocation fixed by C2 laminar screw lost reduction after primary operation, and received anterior release again and finally occipitocervical fusion. All patients were followed up for 15 to 58 (32.0±12.2) months. VAS score was decreased from preoperative 4.2±0.9 to 1.3±0.7 at final follow up and the JOA score was improved from preoperative 11.2±1.2 to 16.9±0.8 at final follow-up. CT scan confirmed that the atlantoaxial or occipitocervical fusion wasgood, and the fusion time was 5 to 9 (6.7±0.6) months. CONCLUSION: Surgical treatment of os odontoideum complicated with atlantoaxial dislocation can achieve satisfactory results, improve the patient's neurological function and improve the quality of life, however the surgical options needs to be individualized.

[Minimally invasive direct lateral approach debridement, interbody bone grafting, and interbody fusion combined with posterior percutaneous pedicle screw fixation for lumbar spinal tuberculosis].

OBJECTIVE: To investigate the clinical efficacy and superiority of direct lateral interbody fusion combined with posterior percutaneous screw fixation in the treatment of lumbar tuberculosis. METHODS: From June 2013 to August 2016, the clinical data of 83 patients with lumbar tuberculosis were retrospectively analyzed, including 55 males and 28 females, aged from 27 to 72 (49.5±13.5) years. These 83 patients were divided into two groups according to different operation methods, 35 cases in group A were treated with direct lateral interbody fusion combined with posterior percutaneous screw fixation;48 cases in group B were treated with anterior traditional extraperitoneal debridement combined with posterior internal fixation. After operation, regular quadruple antituberculosis drugs were continued for 18 months. The operation time, intraoperative blood loss, hospital stay, bone graft fusion time and complications were compared between the two groups. Visual analogue score (VAS) of lumbar pain, Oswestry Disability Index (ODI), sagittal Cobb angle, erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP) values before and after operation were analyzed. RESULTS: The operation was successfully completed in both groups, and the operation mode was not changed during operation. The operation time, intraoperative blood loss and hospital stay were (149.4±13.3) min, (354.3±69.0) ml, (9.4±1.6) d in group A and(116.8±10.0) min, (721.9±172.3) ml, (11.8±1.7) d in group B, respectively, with significant difference between the two groups (P<0.05). The follow up time was (24.2±5.1) months in group A and (24.0±5.0) months in group B, there was no significant difference between two groups (P>0.05). At the follow-up of 4 months after operation, one patient in group A was found to have enlarged psoas major abscess on the contralateral side, and was cured after secondary operation. No sinus formation, cerebrospinal fluid leakage, internal fixation loosening, fracture or distal junction kyphosis were found during follow-up. The fusion time was (5.1±1.6) months in group A and (5.1± 1.7) months in group B, there was no significant difference between two groups (P>0.05). The VAS, ODI score, sagittal Cobb angle, ESR and CRP value of the lesion segment at the last follow-up of the two groups were significantly improved (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The two kinds of operation can obtain satisfactory clinical effect. Direct lateral interbody fusion combined with posterior percutaneous screw fixation can reduce intraoperative blood loss and hospital stay, which is conducive to early rehabilitation of patients.

[Wiltse approach combined with contralateral transforaminal lumbar interbody fusion and conventional surgery for lumbar disc herniation:a case-control study].

OBJECTIVE: To compare the clinical effecty of Wiltse approach combined with contralateral transforaminal lumbar interbody fusion (TLIF) and traditional TLIF in the treatment of lumbar disc herniation and its affect on injury of multifidus muscle. METHODS: From June 2014 to September 2017, 90 patients with lumbar disc herniation combined with lumbar spine instability were divided into two groups (Wiltse approach group and traditional group) depend on the procedure of operation. Wiltse approach group was treated with Wiltse approach screw placement in one side combined with contralateral TLIF. There were 50 patients in Wiltse approach group, including 36 males and 14 females, aged 45 to 72 yearswith an average of (60.4± 3.1) years. The traditional group was treated with traditional TLIF operation. There were 40 patients in the traditional group, including 25 males and 15 females, aged 45 to 74 years with an average of (62.1±3.4) years. The operative time, intraoperative blood loss, accuracy of screw implantation, postoperative drainage volume and drainage tube removal time were recorded in two groups. Visual analogue scale (VAS) and Oswestry Disability Index (ODI)were observed before and 12 months after operation. All patients underwent CT examination preoperative and 12 months postoperative, and the CT values of bilateral multifidus muscle were measured. RESULTS: All the patients were followed up, 40 patients in traditional group were 12 to 18 months with an average of (15.3±4.3) months; and 50 patients in Wiltse approach group were 13 to 24 months with an average of (16.5± 4.1) months. There were no statistically significant differences in operative time and intraoperative blood loss between two groups (P>0.05). The accuracy of screw implantation in Wiltse approach group was higher than traditional group (P<0.05).There was no significant difference in preoperative VAS score and ODI between two groups, and 12 months after operation, VAS score and ODI in Wiltse approach group was significantly lower than traditional group (P <0.05). The postoperative drainage and drainage tube placement time in Wiltse approach group were lower than the traditional group(P<0.05). There was no statistically significant difference in CT value of multifidus muscle before operation between two groups (P>0.05), while there was statistically significant difference after operation (P<0.05). Postoperative CT values of multifidus muscles on decompression and non-decompression side were obviously reduced in traditional group (P<0.05). The CT value of the multifidus muscle on the decompression side of the Wiltse approach group was significantly lower than that before operation(P<0.05), and there was no significant difference before and after the operation on the non-decompression side (P>0.05). CONCLUSION: Compared with traditional surgical procedures, the Wiltse approach nail placement combined with contralateral TLIF has the advantage of accurate nail placement, reducing multifidus muscle damage, and reducing the incidence of postoperative intractable low back pain.

[Nomograma prediction of the surgical treatment in triad of elbow].

OBJECTIVE: To establish an individualized Nomogram prediction model for predicting the postoperative recovery of patients with triad of elbow (TE) by analyzing risk factors of triad of elbow joint. METHODS: From January 2012 to December 2018, 116 patients with TE who met the criteria were collected. The independent risk factors were screened by univariate Logistic regression analysis. The statistically significant risk factors were included in the multivariate Logistic regression model. The R software was used to establish the Nomogram diagram model to predict the postoperative recovery of TE patients. C index was used to verify the discrimination, Calibration plot of the model, and the decision curve (decision curve analysis, DCA) to verify the net clinical benefit rate of the model. RESULTS: Forty-four of the 116 patients with TE developed symptoms after operation, with an incidence of 37.93%. Age (OR=1.930, 95% CI 1.418 to 2.764), work (OR=6.153, 95%CI 1.466 to 31.362), smoking(OR=4.463, 95%CI 1.041 to 2.291), the Mason of radial head(OR=1.348, 95%CI 2.309 to 9.348), the Regan-Morrey of coronal process (OR=4.424, 95%CI 1.751 to 2.426) and postoperative elbow immobilization time(OR=7.665, 95%CI 1.056 to 5.100) were independent risk factors for postoperative recovery of TE (P<0.05). The C-index of Nomogram plot was 0.716. Calibration plot showed that the predictive model was consistent, and the DCA curve showed satisfactory clinical net benefit. CONCLUSION: The Nomogram for predicting postoperative results of TE patients based on six independent risk factors:age, work, smoking, Mason classification of radial head, Regan-Morrey classification of coronal process and immobilization time of elbow joint after operation, has good distinguishing capacity and consistency. Thepredictive model could help clinicians to identify high risk population and establish appropriate intervention strategies.

[Analysis on the causes and prevention strategies of the vascular injury caused by the oblique lateral lumbar fusion].

OBJECTIVE: To analyze the causes of vascular injury occurred in oblique lateral interbody fusion for treating lumbar degenerative diseases, and put forward preventive measures. METHODS: There were 235 patients analyzed from October 2014 to May 2017 in five hospitals, who were treated with oblique lateral interbody fusion with or without posterior pedicle screw fixation. There were 79 males and 156 females with an average age of (61.9±13.5) years old (ranged from 32 to 83 years). There were 7 cases of vascular injury, including 4 cases of segmental vessel injury, 1 case of left common iliac artery injury, 1 case of left common iliac veininjury and 1 case of ovarian vein injury. RESULTS: The follow up time ranged from 6 to 36 months, averagely (15.6±7.5) months. There was no pedicle screw loosen or fracture. The low back pain VAS decreased from preoperative 6.7±2.3 to 1.4±0.8 at the latest follow-up, which was statistically difference(t=7.21, P=0.033). The ODI decreased from preoperative (36.5±7.7)% to (9.4±3.6)% at the latest follow-up, which was statistically difference (t=8.11, P=0.025). CONCLUSION: Oblique lateral interbody fusion technique provides a new method for minimally invasive fusion of lumbar internal fixation. However, it has a risk of vascular injury. In order to effectively prevent the occurrence of vascular injury, the operative indications and careful and meticulous operation should be strictly grasped.

Key factors affecting photoactivated fungicidal activity of sodium pheophorbide a against Pestalotiopsis neglecta.

Recently, photodynamic therapy (PDT) and photoactivated pesticides have attracted considerable research attention. In the present study, we aimed to investigate the photodynamic activity of a chlorophyllous derivative, sodium pheophorbide a (SPA), and to evaluate its potential as a photoactivated fungicide. The singlet oxygen quantum yield, the photoreaction process, the anti-photobleaching ability in sterile water (H2O), the effect of light conditions on its antifungal activity, and its stability were all investigated. SPA showed significant fungicidal activity and photostability, during which Type I and Type II photodynamic reactions occurred simultaneously on Pestalotiopsis neglecta, and the influence of Type I was slightly larger than that of Type II. In addition, light promoted the antifungal activity of SPA. In particular, the antifungal activity was enhanced with increasing light intensity, and was strongest under 8000 lx conditions. Under monochromatic light sources, antifungal activity was strongest under green light s; however, the effect of monochromatic light was not as good as that of white light. From 0 to 24 h, the antifungal effect of the SPA solution was enhanced; however, the activity of the solution began to weaken after 24 h. Furthermore, our study confirmed that the antifungal activity of SPA was stable under different temperatures, pH values, and UV irradiation durations.

[Comparison of the effects of injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty in the treatment of osteoporotic thoracolumbar burst fractures].

OBJECTIVE: To assess the curative effects of injured vertebra pedicle fixation combined with vertebroplasty and short-segment pedicle screw fixation combined with vertebroplasty in treatment of osteoporotic thoracolumbar burst fractures. METHODS: Seventy patients with osteoporotic thoracolumbar burst fractures who met the inclusion criteria were collected in the study from January 2015 to December 2017. Among them, 35 patients were treated with injured vertebra pedicle fixation combined with vertebroplasty (group A), including 20 males and 15 females, aged from 55 to 74 years with an average of (64.03± 7.82) years. Twenty-six cases were type A3 and 9 cases were type A4 according to the AO typing;another 35 patients were treated with short segment pedicle screw fixation combined with vertebroplasty (group B), including 18 males and 17 females, aged from 54 to 72 years with an average of (62.78±6.40) years. Twenty-eight cases were type A3 and 7 cases were type A4 according to AO typing. Operation length, intraoperative bleeding volume, complication, imaging parameters and clinical effects were compared between the two groups. RESULTS: All the patients were followed up for at least 12 months. There were no significant differences in gender, age, injury site, preoperative VAS, Cobb angle, and injured vertebral height before surgery. There were no significant differences in operation length, intraoperative bleeding volume between two groups. In terms of VAS scores before surgery, 1 week after surgery, and at the final follow up, group A was 5.5 ±2.5, 1.8 ±0.8, 0.9 ±0.4, group B was 5.4 ± 2.3, 1.7±0.6, 1.2±1.8, respectively;injured vertebral height was (40.4±8.8)%, (92.0±4.9)%, (87.1±3.8)% in group A, and (41.2±6.6)%, (93.2±4.6)%, (80.0±4.3)% in group B;Cobb angle was (18.4±6.9) °, (2.8±2.2) °, (4.2±2.6) ° in group A, and (16.8±7.2) °, (2.7±2.5) °, (6.0±2.4) ° in group B. There were significant differences in the 3 parameters above before the operation and at the final follow up in all groups (P<0.05). There were significant differences in the Cobb angle and injured vertebral height between 1 week after operation and at the final follow up (P<0.05). At the final follow up, injured vertebral height in group A was obviously better than that in group B (P<0.05). Internal fixation failure occurred in 2 cases from the group A, and occurred in 4 cases from the group B. There were no neurological complications in both groups. CONCLUSION: For osteoporotic thoracolumbar vertebral burst fractures, injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty can achieve good clinical effects. However, injured vertebra pedicle fixation combined with vertebroplasty is better at maintaining postoperative vertebral height and sagittal arrangement, and reducing internal fixation related complications. The treatment strategy is worthy of application and promotion.

The biomechanical study of a modified lumbar interbody fusion-crenel lateral interbody fusion (CLIF): a three-dimensional finite-element analysis.

To analyze the biomechanical stability of a redesigned cage, a new lateral plate and the effect of length of cage in CLIF, an L4-L5 finite element model was performed. Six different internal fixation methods were designed and operated under six conditions (Stand-alone CLIF; CLIF with unilateral pedicle screws (CLIF + UPS); CLIF with bilateral pedicle screws (CLIF + BPS); CLIF with lateral plate (CLIF + LP); CLIF with lateral plate and unilateral pedicle screws (CLIF + LP + UPS); CLIF with lateral plate and bilateral pedicle screws (CLIF + LP + BPS)). Ranges of motion (ROM) and stress distribution were evaluated. The effect of the length of cage was analyzed. The ROMs of stand-alone CLIF group and other internal fixation groups were decreased by >90% compared with the intact group. The CLIF + LP + BPS group has the minimum ROM. The CLIF + LP group has smaller ROM than stand-alone group. The stand-alone group has the minimum stress except for extension condition. The CLIF + LP model has less ROM, but a greater stress load was observed in the lateral plate. As for the length of cage, the largest stress is located at the junction between cage and distal end plate, especially in the epiphyseal ring and cortical compact. We conduct a new 'cylinder wall theory' that the cage should be placed to cover the epiphyseal ring. We recommend the length of cage should cover the epiphyseal ring to reduce the subsidence of cage.

[Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis].

OBJECTIVE: To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients. METHODS: The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). RESULTS: All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (P<0.05). CONCLUSION: Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

Safe trajectory for an occipital condyle screw: A computer simulation study.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of posterior occipital condyle screw (OCS) placement analysis of the safe trajectory area for screw insertion. METHODS: Computed tomographic angiography scans of patients (46 males and 27 females) with normal occipitocervical structures were obtained consecutively. Vertebral artery (VA)-occiput distance <4.0 mm was defined as "unfeasible" for OCS fixation, and occipital-atlas angulation was measured to assess the feasibility of screw placement. Next, the placement of 3.5 mm diameter OCS was simulated, the probability of breach of structures surrounding occipital condyles was calculated, and placement parameters were analyzed. RESULTS: OCS placement was feasible in 91.1% (133/146) of occipital condyles, and the feasible probability also presented a significant sex-related difference: The probability was higher for males than for females (95.7% vs. 83.3%, p < 0.05). The incidence of anatomical structures injured under screw placement limitation was 18.8% (VA), 81.2% (hypoglossal canal), 59.4% (occipital-atlas joint), and 40.6% (occiput bone surface). There were no significant differences between the left and right condyles in relation to the measured parameters (p > 0.05). The screw range of motion was significantly smaller in females than in males (p < 0.05). The feasibility of OCS placement and OCS range of motion were significantly greater in the kyphosis group (>5°) than in the other two groups (p < 0.05). CONCLUSION: OCS placement is a feasible technique for occipital-cervical fusion. The male group and occipitocervical region kyphosis group had a wider available space for OCS placement. Tangent angulation may be useful for the accurate and safe placement of an OCS.

Modified Broström Repair With and Without Augmentation Using Suture Tape for Chronic Lateral Ankle Instability.

OBJECTIVE: To compare the clinical and radiological outcome between the modified Broström repair with augmentation using suture tape (MBA) and the modified Broström repair (MB) for patients with chronic lateral ankle instability. METHODS: A retrospective study was performed in Ningbo No. 6 Hospital. The study included 53 patients who underwent surgical treatment from March 2014 to July 2016 and were followed for 2 years. A total of 25 patients underwent modified Broström repair with augmentation using suture tape, and 28 patients were treated with modified Broström repair. Patients were evaluated using the American Orthopedic Foot and Ankle Scale (AOFAS) hindfoot scale, the Foot and Ankle Ability Measure (FAAM) score, range of motion (ROM), and the visual analogue scale (VAS). The talar tilt angle (TTA) and anterior talar translation (ATT) were used to evaluate the mechanical stability. All radiological outcomes were measured by two orthopaedic surgeons, with the measurements repeated 3 days later. RESULTS: The mean age of the patients was 26.6 ± 17.8 years in the MBA group and 28.1 ± 19.4 years in the MB group, and no statistical difference in preoperative data was found between two groups. There were significant differences before and after the operation within the groups. Both groups achieved satisfactory outcomes, and significant improvements (VAS, FAAM, AOFAS, TTA, and ATT) were observed between the 1-year follow-up and final follow-up (P < 0.05). The MBA group showed significant improvement in the FAAM Sport (87.1 ± 5.4 vs 78.2 ± 12.0, P = 0.001) and total scores (93.1 ± 2.3 vs 90.5 ± 5.1, P = 0.027) at the final follow-up compared with the MB group, and for the other outcomes, there were no significant differences between the two groups. CONCLUSION: The modified Broström repair with augmentation using suture tap for chronic lateral ankle instability achieves a better outcome; however, further research is necessary.

[Efficacy of bilateral sagittal cross percutaneous kyphoplasty for preventing recurrent fracture of the cemented vertebrae].

OBJECTIVE: To explore the efficacy of bilateral sagittal cross percutaneous kyphoplasty(PKP) for preventing recurrent fracture of the cemented vertebrae. METHODS: From January 2017 to June 2017, 85 patients with single-segment osteoporotic vertebral compression fractures(OVCFs) were treated by bilateral sagittal cross PKP(cross group). There were 35 males and 50 females with an average age of (70.1±8.3) years old in cross group. Another 85 patients with single-segment OVCFs were treated by traditional PKP (traditional group). There were 37 males and 48 females with an average age of (73.3±9.5) years old in traditional group. The cement distribution condition, recurrent fracture of the cemented vertebrae, the anterior vertebral body height and sagittal Cobb angle, visual analogue scale(VAS) were observed in two groups. RESULTS: All patients underwent operation successfully. The follow-up time were (11.8±4.5) months in cross group and (12.1±3.7) months in traditional group. In cross group, all patients' bone cement touched the upper and lower endplates of the vertebral body while 67 cases (78.8%) in traditional group did with significant difference between two groups (P<0.05). No patient in cross group suffered recurrent fracture of the cemented vertebrae while 10 cases (11.8%) in traditional group did with significant difference between two groups(P<0.05). The anterior vertebral body height, sagittal Cobb angle and VAS in both groups were obvious improved at 2 days after operation (P<0.05) and there were no significant difference between two groups at 2 days after operation and the final follow-up(P>0.05). CONCLUSIONS: Bilateral sagittal cross PKP was a simple, safe and effective technique which can make bone cement distribute in the fractured vertebral body and contact the upper and lower endplates of the vertebral body, thus preventing the recurrent fracture of the cemented vertebrae.

Missed manubriosternal dislocation in patient with thoracolumbar fracture, a case report.

BACKGROUND: Spine fractures combined with sternal injury are most commonly occur in the thoracic region. Lower cervical and thoracolumbar injuries have also been reported, especially for the patients with manubriosternal dislocation. The type of spine injury is easily recognized in initial presentation, but we may miss the sternal fracture and manubriosternal dislocation. CASE PRESENTATION: A 23-year-old male patient complained with chest, right ankle, and lumbar pain after a fall at ground level, with diagnosis of right distal tibial fracture, sternal fracture, calcaneus fracture, and L2 vertebral fracture. However, neurologically he was completely normal. He underwent the operation for his lower extremity and spine, but we missed his manubriosternal dislocation after discharged. After one month, he came to the clinic with complained of chest pain, the imaging exams showed anterior dislocation of manubriosternal joint. We chose conservative treatment for manubriosternal dislocation. He was followed up at monthly intervals and radiographs along with computerized tomography showed satisfactory in fracture healing of lumber and the sternal fracture. However, the manubriosternal dislocation was malunioned. The patient had appearance deformity of the manubriosternal joint. CONCLUSION: This case supports the concept of the existence and clinical relevance of the thoracic cage theory, the thoracolumbar vertebrae should also be included in the thoracic cage theory.

[One stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers].

OBJECTIVE: To assess the clinical results of one stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers. METHODS: From February 2009 to April 2015, 19 teenagers with Grauer type IIB dens fractures not amenable to anteiror screw fixation were enrolled and treated using one stage temporary atlantoaxial segmental fixation and reduction without fusion. There were 14 males and 5 females, aged from 14 to 32 years with an average of (24.6±5.0 ) years. The internal fixation was removed after bone healing confirmed by CT scan. At the last follow-up (at least 1 year after internal fixation removal), dynamic CT was used to assess the atlantoaxial rotation activity. Visual analogue scale (VAS) was recorded before the first operation, before the second operation (removal of internal fixation) and at the last follow-up. Neck Disability Index(NDI) was used to evaluate the efficacy before the second operation (removal of internal fixation) and the last follow-up. RESULTS: After operation, 2 patients developed the symptoms of occipital nerve stimulation such as numbness and pain in the occipitocervical region, and were treated with drugs such as dehydration and neurotrophic drugs, and the symptoms were relieved after 1 to 2 months. All the internal fixations were removed and all the patients were followed up more than 1 year, with time ranging from 18 to 25 months and an average of (21.47±2.41) months. The time of bone fusion after operation was 6 to 10 months with the mean of(8.21±1.27) months. Secondary surgical removal of internal fixation were performed immediately after fracture healing without internal fixation failure. The symptoms of neck pain improved significantly after operation, VAS score decreased from 6.74±0.65 before operation to 0.42±0.51 at the last follow-up after the second operation (removal of internal fixation), with statistically significant differences(P<0.01). The NDI value decreased from (10.58±2.04)% before the second operation (removal of internal fixation) to (3.79±2.23)% at the last follow-up after the second operation (removal of internal fixation), with statistically significant difference(P<0.01). At the last follow-up after the second operation (removal of internal fixation), dynamic CT showed that the unilateral rotation of the atlantoaxial spine reached (15.73±5.57)° to the left, (15.55±5.78)° to the right, and the overall rotation of the atlantoaxial spine was (31.28±10.71)°. CONCLUSIONS: One stage temporary atlantoaxial segmental fixation and reduction for the treatment of Grauer type IIB dens fractures not amenable to anteiror screw fixation in teenagers can avoid the loss of atlantoaxial rotation function caused by atlantoaxial fusion, and to some extent retain the rotation activity of atlanto-axial joint.