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This study was a retrospective review of prospectively collected clinical data.To evaluate the clinical and radiologic outcomes of computer-assisted minimally invasive spine surgery transforaminal lumbar interbody fusion (CAMISS-TLIF) and open TLIF for the treatment of 1-level degenerative lumbar disease.Minimally invasive TLIF is becoming increasingly popular; however, the limited space and high rate of hardware complications associated with this method are challenging to surgeons. Computer-assisted navigation has the potential to dynamically show the fine anatomic structures, which could theoretically facilitate minimally invasive spine procedures.Sixty-one patients underwent 1-level TLIF procedures (30, CAMISS-TLIF; 31, open TLIF). The computer-assisted navigation system was used for CAMISS-TLIF, whereas conventional fluoroscopy was used for open TLIF. Demographic, operative, visual analog scale, and Oswestry disability index data were collected. Screw insertion was assessed by computed tomography, and radiologic fusion based on Bridwell grading was evaluated 2 years after surgery by independent investigators.The CAMISS-TLIF group had significantly less blood loss, postoperative drain, need for transfusion, and initial postoperative back pain; earlier rehabilitation; and shorter postoperative hospitalization than the open TLIF group, whereas CAMISS-TLIF took longer surgical time than open TLIF. However, no significant differences between the 2 groups in visual analog scale scores and Oswestry disability index were observed at 3 months, 1 year, and 2 years postoperatively. A total of 93.33% and 73.39% of screws in the CAMISS and open groups, respectively, had no pedicle perforation (P=0.016), and the fusion rate was similar in both groups (P=0.787).Computer-assisted navigation facilitated minimally invasive spine surgery-TLIF. CAMISS-TLIF was superior to open TLIF for treating 1-level degenerative lumbar disease, although it required longer operation time in the initial stage. CAMISS-TLIF showed several benefits compared with open TLIF, including less intraoperative blood loss, postoperative drainage, and pain; earlier rehabilitation; and shorter postoperative hospitalization.

Epoxy resin, a brittle material, is a widely used thermosetting material, and one of the mature methods to toughen it is to use liquid rubber. Which can not only improve the mechanical properties of epoxy matrix, but also change other properties of epoxy matrix. In this paper, hydroxyl-terminated liquid Nitrile Rubber (HTBN) is used to modify a kind of room temperature initially-cured epoxy resin. The size of the rubber particles becomes larger as the content of HTBN increases. The rubber particles formed by HTBN reduce the crosslinking degree of the epoxy resin matrix, resulting in a small decrease in the glass ring transition temperature of the composite. Meanwhile, the rubber particles hinder the conduction of phonons, so that the thermal conductivity and thermal diffusivity of the composite material are reduced, but the reduction range is small. At the same time, the rubber phase introduces two polarization relaxation processes into the matrix, causing the relative permittivity and dielectric loss to increase abruptly at low temperature and low frequency.

To compare one-time accuracy rate between simulated freehand (SFH) and navigation simulated (NS) pedicle screw insertion, assuming no second chance to correct screws.A simulated, comparative, cross-sectional study was conducted on 69 patients undergoing lumbar spine surgery. An intraoperative registration system captured the planned point of entry and trajectory of pedicle screws for both SFH under direct visualization and NS under navigation-aided visualization. Pedicle screw insertion was simulated for each captured image (370 screws) using Surgimap. Rajasekaran's method helped evaluate the point of entry accuracy and trajectory.Accuracy rate was better for the NS method (97.8%) than for the SFH method (63.8%). Of 370 screws in the SFH group, 134 penetrated the cortex, with 31 resulting in4 mm penetration. Of 370 screws in the NS group, 8 penetrated the cortex,4 mm penetration. Of 134 misplaced screws in the SFH group, 64 were due to error in the point of entry, 63 were due to error in the trajectory angle, and 7 were due to both errors. Of 8 errors in the NS group, 7 were due to the point of entry.Intraoperative navigation had significantly better one-time accuracy of pedicle screw insertion than freehand insertion and should be used to avoid injury to the pedicle and surrounding tissue from screw reinsertion.

To retrospectively assess the feasibility and safety of percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation.Thirty patients admitted from April 2012 to May 2014 in Beijing Jishuitan Hospital with cervical fracture underwent pedicle screw fixation using intraoperative three-dimensional fluoroscopy-based navigation, with 8 patients using minimally invasive technique (CAOS-MIS group), and the other 22 patients using conventional open approach (CAOS-open group). Operative time, blood loss and postoperative neurovascular complications were recorded. Screw positions were studied by postoperative CT scan. All patients were followed up for at least 6 months. Neck visual analogue score (VAS) and American Spinal Injury Association (ASIA) classification were evaluated preoperatively and at 6-month follow-up. Independent-sample t test and Chi-Square test were used for statistical analysis.Operation time was (139 ± 18) minutes and blood loss was (73 ± 40) ml in CAOS-MIS group and correspondingly (154 ± 42) minutes and (296 ± 171) ml in CAOS-open group. The blood loss in CAOS-MIS group was significantly lower than that in CAOS-open group (t = 5.695, P0.01). No screw-related injury to nerve or vertebral artery was observed. Thirty-four screws were placed in CAOS-MIS group with 28 screws (82.4%) classified as Grade I, meanwhile in CAOS-open group 108 screws were placed with 96 screws (88.9%) classified as Grade I. There was no statistical difference between the two groups (χ² = 0.998, P0.01). VAS score showed no statistical difference preoperatively (t = 0.334, P0.01), however statistical difference existed at 6 months follow-up (t = 4.111, P0.01) with (0.4 ± 0.5) in CAOS-MIS group and (1.5 ± 0.7) in CAOS-open group. There were 1 patient from class B to improve to D, 1 case from D to E in CAOS-MIS group, and 1 patient from class A to improve to B, 1 case from B to D, 2 cases from C to D, 3 cases from D to E in CAOS-open group 6 months after surgery. Cervical X-ray demonstrated fractures healed well in all cases at 6 months follow-up.It is feasible and safe for percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation, which can also decreases the incidence of postoperative neck pain.

Minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) is a challenging technique with a long learning curve. We combined computer-assisted navigation and MI TLIF (CAMISS TLIF) to treat lumbar degenerative disease. This study aimed to evaluate the learning curve associated with computer-assisted navigation MI spine surgery (CAMISS) and TLIF for the surgical treatment of lumbar degenerative disease. Seventy four consecutive patients with lumbar degenerative disease underwent CAMISS TLIF between March 2011 and May 2015; all surgeries were performed by a single surgeon. According to the plateau of the asymptote, the initial 25 patients constituted the early group and the remaining patients comprised the latter group. The clinical evaluation data included operative times, anesthesia times, intraoperative blood losses, days until ambulation, postoperative hospital stays, visual analog scale (VAS) leg and back pain scores, Oswestry disability index (ODI) values, Macnab outcome scale scores, complications, radiological outcomes, and rates of conversion to open surgery. The complexity of the cases increased over the series, but the complication rate decreased (12.00%-6.12%). There were significant differences between the early and late groups with respect to the average surgical times and durations of anesthesia, but no differences in intraoperative blood losses, days until ambulation, postoperative hospital stays, complication rate, VAS, ODI, Macnab outcome scale scores, or solid fusion rates. There was no need for conversion to open procedures in either group. Our study showed that a plateau asymptote for CAMISS TLIF was reached after 25 operations. The later patients experienced shorter operative times and anesthesia durations.

As the clean energy developing rapidly in recent years, the operational mode of power system was adjusted persistently because it was impacted by the randomness of clean energy output. Meanwhile, the efficiency of transmission grid was decreasing in certain level for the same reason. The production simulation model of power system was presented, and the power source which considering the output characteristics of different clean energy was described respectively. In additionally, the analytical method of efficiency assessment was proposed to assess the impact degree of clean energy. Moreover, the efficiency index of power transmission system programming was adopted to choose planning scheme. At last, three planning schemes of a power grid with massive clean energy are analyzed to confirm the production simulation model and assessing method.

Retrospective comparative cohort series.To evaluate the accuracy and feasibility of minimally invasive surgical (MIS) techniques incorporating with intraoperative 3-dimensional fluoroscopy-based navigation (ITFN) for treating Hangman fracture.MIS screw fixation for Hangman fracture can decrease iatrogenic soft-tissue injury, but increase the risk of instrumentation-related complications due to lack of anatomical landmarks. With the advantages of obtaining intraoperative real-time images, automatic registration, and 3-dimensional views, the ITFN system seems to be an inherent partner for MIS.20 patients with Hangman fracture underwent C2-C3 pedicle screw fixation using ITFN. 6 patients used MIS technique, with the other 14 patients using conventional open technique. Operative time and blood loss were recorded. The accuracy of screw positions was studied by postoperative CT scan. Neck pain visual analogue score (VAS) was evaluated and the fusion status was ascertained in 6-month follow-up.The average operative time was 134.2 ± 8.0 minutes in computer-assisted orthopaedics surgery (CAOS)-MIS group and 139.3 ± 25.8 minutes in CAOS-open group (P 0.01). The blood loss was 66.7 ± 25.8 mL in CAOS-MIS group and 250.0 ± 141.4 mL in CAOS-open group (P 0.01). A total of 80 screws were inserted. No screw-related neurovascular injury was observed. 83.3% (20/24) screws in CAOS-MIS group and 89.3% (50/56) screws in CAOS-open group were grade 1 screw (P 0.01). No grade 3 screw was detected in both groups. Compared with the CAOS-open group (1.7 ± 0.6), neck pain VAS in 6-month follow-up in CAOS-MIS group (0.3 ± 0.5) was significantly lower (P 0.01). Solid fusion was demonstrated in all the cases.The integration of these 2 techniques MIS and ITFN, we call "computer assisted minimally invasive spinal surgery," is proved to be feasible and safe for treating Hangman fracture with the advantage of significantly reduced iatrogenic soft tissue injury. So we think CAMISS technique represents the most recent modification of spine surgery.