Biomechanical behaviour of a novel bone cement screw in the minimally invasive treatment of Kummell's disease: a finite element study.

OBJECTIVE: To investigate and evaluate the biomechanical behaviour of a novel bone cement screw in the minimally invasive treatment of Kummell's disease (KD) by finite element (FE) analysis. METHODS: A validated finite element model of healthy adult thoracolumbar vertebrae T12-L2 was given the osteoporotic material properties and the part of the middle bone tissue of the L1 vertebral body was removed to make it wedge-shaped. Based on these, FE model of KD was established. The FE model of KD was repaired and treated with three options: pure percutaneous vertebroplasty (Model A), novel unilateral cement screw placement (Model B), novel bilateral cement screw placement (Model C). Range of motion (ROM), maximum Von-Mises stress of T12 inferior endplate and bone cement, relative displacement of bone cement, and stress distribution of bone cement screws of three postoperative models and intact model in flexion and extension, as well as lateral bending and rotation were analyzed and compared. RESULTS: The relative displacements of bone cement of Model B and C were similar in all actions studied, and both were smaller than that of Model A. The minimum value of relative displacement of bone cement is 0.0733 mm in the right axial rotation of Model B. The maximum Von-Mises stress in T12 lower endplate and bone cement was in Model C. The maximum Von-Mises stress of bone cement screws in Model C was less than that in Model B, and it was the most substantial in right axial rotation, which is 34%. There was no substantial difference in ROM of the three models. CONCLUSION: The novel bone cement screw can effectively reduce the relative displacement of bone cement by improving the stability of local cement. Among them, novel unilateral cement screw placement can obtain better fixation effect, and the impact on the biomechanical environment of vertebral body is less than that of novel bilateral cement screw placement, which provides a reference for minimally invasive treatment of KD in clinical practice.

Combining Music and Indoor Spatial Factors Helps to Improve College Students' Emotion During Communication.

Against the background of weakening face-to-face social interaction, the mental health of college students deserves attention. There are few existing studies on the impact of audiovisual interaction on interactive behavior, especially emotional perception in specific spaces. This study aims to indicate whether the perception of one's music environment has influence on college students' emotion during communication in different indoor conditions including spatial function, visual and sound atmospheres, and interior furnishings. The three-dimensional pleasure-arousal-dominance (PAD) emotional model was used to evaluate the changes of emotions before and after communication. An acoustic environmental measurement was performed and the evaluations of emotion during communication was investigated by a questionnaire survey with 331 participants at six experimental sites [including a classroom (CR), a learning corridor (LC), a coffee shop (CS), a fast food restaurant (FFR), a dormitory (DT), and a living room(LR)], the following results were found: Firstly, the results in different functional spaces showed no significant effect of music on communication or emotional states during communication. Secondly, the average score of the musical evaluation was 1.09 higher in the warm-toned space compared to the cold-toned space. Thirdly, the differences in the effects of music on emotion during communication in different sound environments were significant and pleasure, arousal, and dominance could be efficiently enhanced by music in the quiet space. Fourthly, dominance was 0.63 higher in the minimally furnished space. Finally, we also investigated influence of social characteristics on the effect of music on communication in different indoor spaces, in terms of the intimacy level, the gender combination, and the group size. For instance, when there are more than two communicators in the dining space, pleasure and arousal can be efficiently enhanced by music. This study shows that combining the sound environment with spatial factors (for example, the visual and sound atmosphere) and the interior furnishings can be an effective design strategy for promoting social interaction in indoor spaces.

[Clinical application of cervical pedicle screw implantation technique under regional method].

OBJECTIVE: To investigate the effectiveness of cervical pedicle screw implantation technique under regional method. METHODS: The clinical data of 85 patients who met the selection criteria between April 2010 and May 2018 were retrospectively analyzed. There were 57 males and 28 females, aged 35-68 years, with an average of 57.6 years. Among them, there were 10 cases of ossification of posterior longitudinal ligament, 68 cases of cervical spondylosis with multilevel stenosis, 3 cases of cervical tumor, 1 case of congenital malformation, and 3 cases of cervical trauma; the lower cervical spine lesions involved C 3-C 7. Preoperative Frankel spinal cord injury grading: 2 cases of grade C, 51 cases of grade D, and 32 cases of grade E. Cervical pedicle screw implantation technique under regional method was performed with a total of 618 pedicle screws. Postoperative changes in neurological symptoms were observed; cervical mouth opening anteroposterior and lateral X-ray films and cervical CT examinations were performed to evaluate the pedicle screws position. RESULTS: The operation time was 2.5-4.0 hours, with an average of 3.0 hours. The intraoperative blood loss was 180-550 mL, with an average of 345 mL. No intraoperative vascular or nerve injury occurred. The patients with neurological symptoms were relieved to varying degrees. There were 2 cases of superficial incision infection after operation, the wound healed after enhanced dressing change. The postoperative hospital stay was 5-14 days, with an average of 8.4 days. At discharge, Frankel neurological grading was grade D in 26 patients and grade E in 59 patients. All the patients were followed up 6-24 months, with an average of 13 months. At last follow-up, cervical X-ray films showed the good pedicle screw fixation without loosening. Cervical CT evaluated the position of pedicle screws: 523 pedicle screws (84.7%) in grade Ⅰ, 80 (12.9%) in grade Ⅱ, and 15 (2.4%) in grade Ⅲ; the accuracy rate of the screw position was 97.6%. CONCLUSION: Cervical pedicle screw implantation technique under regional method can significantly improve the success rate of screw implantation. It is easy to operate, does not destroy the bone cortex, and has stable fixation.

Intraoperative microwave inactivation in-situ of malignant tumors in the scapula.

OBJECTIVE: To explore the feasibility and effect of microwave in situ inactivation of malignant primary or metastatic tumors in the scapula. METHODS: Seventeen patients (12 men, 5 women, mean age 48 years [range, 13-59 years]) with malignant primary or metastatic tumors involving the scapula were treated by microwave inactivation between June 1998 and February 2008. There were 12 malignant primary bone and 5 metastatic tumors. In 14 cases Area Sl was involved and in 3 cases both Areas S1 and S2. All 17 cases were by making a dorsal arc- or "∩-" shaped incision to expose the tumor, protecting the surrounding soft tissues with a copper grid, and then heated the tumors locally with 2450 MHz microwave to 50°C for 20 min, after which all or some of the necrotic tumor tissue was removed, preserving the support role of the scapula. RESULTS: The operation time was 60-180 min (mean 120 min) and blood loss was 300-1000 mL (mean 460 mL). No serious intraoperative or postoperative complications occurred in any patient. The patients were followed up for 3 months to 10 years (mean 4.2 years). Three patients with Ewing's sarcoma in the scapula had pulmonary, cerebral and systemic multiple metastases and died 8~24 months after surgery. Three patients with malignant fibrous histiocytoma died of pulmonary and systemic multiple metastases 10~22 months after surgery; one patient had recurrence 6 months after surgery and survived with tumor. Five patients with metastatic tumor in the scapula died of non-scapular metastatic tumor 6~14 months after surgery. The other five patients with primary malignant bone tumors had no recurrence or metastasis during follow-up. Three cases had restricted extension of the shoulder joint with unrestricted protraction and retroflexion after surgery. CONCLUSION: In situ microwave inactivation features simple surgery, reliable effects and patient acceptability, making it an ideal surgical method for malignant tumors in the scapula.

One-stage combined posterior and anterior approaches for excising thoracolumbar and lumbar tumors: surgical and oncological outcomes.

STUDY DESIGN: Retrospective clinical and radiologic evaluation. OBJECTIVE: To investigate the feasibility of a 1-stage combined posterior and anterior approaches for excising thoracolumbar and lumbar tumors with the patient lying in the lateral position. SUMMARY OF BACKGROUND DATA: Traditional anteroposterior approaches for total spondylectomy require a 2-stage operation or changing the patient's position, with secondary sterilization in the one stage. So the surgical time, cost and trauma, as well as blood loss, would be increased. One-stage en bloc spondylectomy with the patient lying in the lateral position may be a good way for improving it. METHODS: This study retrospectively reviewed 18 patients with thoracolumbar and lumbar spinal tumors who underwent spondylectomy. All patients were observed up, and their status was evaluated by clinical and imaging studies. RESULTS: Total en bloc spondylectomy was performed successfully in 15 patients, and 3 patients underwent bulk vertebrectomy. All patients were observed up for 18 months to 3 years (mean, 2 years). Posterior pedicle screw fixation and anterior intervertebral titanium mesh placement were stable in all patients, with satisfactory positions. Two patients with preoperative neurologic deficits recovered less than 3 weeks after surgery. One patient with thyroid metastasis underwent artificial joint replacement 5 months after surgery. Two patients with metastatic tumor died 6 months and 8 months, respectively, after surgery. Ten months after surgery, local tumor recurred in one patient with chondrosarcoma. One patient with Ewing's sarcoma died due to distal metastasis 1 year after surgery. CONCLUSION: The 1-stage combined posterior and anterior approaches with the patient lying in the lateral position, used to excise thoracolumbar and lumbar spinal tumors, is feasible and permits sufficient exposure, reduces the risk of neurovascular injury and blood loss during surgery, facilitates total en bloc spondylectomy and spinal reconstruction, and reduces the surgical time of a 2-stage procedure and repositioning the patient. This method can be used effectively for excising spinal tumors.

[Comparative study of transurethral electrovaporization of prostate versus transurethral resection of prostate on benign prostatic hyperplasia].

OBJECTIVES: To compare the efficacy of transurethral electrovaporization of prostate (TUVP) with transurethral resection of prostate (TURP). METHODS: 206 patients with symptomatic benign prostatic hyperplasia (BPH) whose prostatic sizes were all less than 60 grams were randomly divided into two groups. 97 cases were treated by TUVP while the other 109 cases were treated by TURP. The patients who underwent either TUVP or TURP were followed up for 12-34 months with an average of 20 months postoperatively. RESULTS: Both groups showed the significant decline in the mean IPSS (international prostatic symptom score) (P < 0.01), the mean PVR (Postovoiding Residual Volume) (P < 0.01), while increase in mean Qmax (Peak uroflow rate) (P < 0.01) in 12 months, 24 months after the operation. There were significant differences in the mean duration of operation or catheterization postoperatively (P < 0.05). The main complications of post-operation in the two groups were stress incontinence, TUR syndrome, urethral stricture, secondary bleeding. CONCLUSIONS: Both TUVP and TURP are effective treatment for the patient with BPH whose prostatic size is less than 60 grams. TUVP spends shorter time of the operation and postoperative catheterization than that of TURP.