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Background: Intraoperative CT-guided navigation (iCT-navigation) has been reported to improve the accuracy and safety of transpedicular screw placement in primary spinal surgery. However, due to a disrupted bony anatomy and scarring tissue, revision spinal surgery can be challenging. The purpose of this study was to evaluate the accuracy and safety of iCT-navigation for screw placement at the virgin site versus the revision site in revision thoracolumbar spinal surgery. Method: In total, 254 screws were inserted in 27 revision surgeries, in which 114 (44.9%) screws were inserted at the site with previous laminectomy or posterolateral fusion (the revision site), 64 (25.2%) were inserted at the virgin site, and 76 (29.9%) were inserted to replace the pre-existing screws. CT scans were conducted for each patient after all screws were inserted to intraoperatively confirm the screw accuracy. Results: In total, 248 (97.6%) screws were considered accepted. The rate of accepted screws at the virgin site was 98.4% (63/64) versus 95.6% (109/114) at the revision site (p: 0.422). There were six (2.4%) unaccepted screws, which were immediately revised during the same operation. There was no neurological injury noted in our patients. Conclusion: With the use of iCT-navigation, the rate of accepted screws at the revision site was found to be comparable to that at the virgin site. We concluded that iCT-navigation could achieve high accuracy and safety for transpedicular screw placement in revision spinal surgery and allow for the immediate revision of unaccepted screws.

Biomechanical performance of longitudinal component in dynamic hybrid devices was evaluated to display the load-transfer effects of Dynesys cord spacer or Isobar damper-joint dynamic stabilizer on junctional problem based on various disc degenerations. The dynamic component was adapted at the mildly degenerative L3–L4 segment, and the static component was fixed at the moderately degenerative L4–L5 segment under a displacement-controlled mode for the finite element study. Furthermore, an intersegmental motion behavior was analyzed experimentally on the synthetic model under a load-controlled mode. Isobar or DTO hybrid fixator could reduce stress/motion at transition segment, but compensation was affected at the cephalic adjacent segment more than the caudal one. Within the trade-off region (as a motion-preserving balance between the transition and adjacent segments), the stiffness-related problem was reduced mostly in flexion by a flexible Dynesys cord. In contrast, Isobar damper afforded the effect of maximal allowable displacement (more than peak axial stiffness) to reduce stress within the pedicle and at facet joint. Pedicle-screw travel at transition level was related to the extent of disc degeneration in Isobar damper-joint (more than Dynesys cord spacer) attributing to the design effect of axial displacement and angular rotation under motion. In biomechanical characteristics relevant to clinical use, longitudinal cord/damper of dynamic hybrid lumbar fixators should be designed with less interface stress occurring at the screw-vertebral junction and facet joint to decrease pedicle screw loosening/breakage under various disc degenerations.

Conventional laminectomy for spine decompression involves inherent complications resulting from perioperative traumatization of posterior structures. Minimally invasive decompression was developed to address these issues. Full endoscopic spine surgery has shifted the paradigm from disc pathology to spinal stenosis by overcoming the limitation of bony procedures with evolving endoscopic instruments. However, a steep learning curve restricts the development of endoscopic decompression. The purpose of this study is to describe full endoscopic uniportal unilateral laminotomy for bilateral decompression through the interlaminar approach and to evaluate its efficacy and safety in 2 years of follow-up.A total of 106 patients (45 men, 61 women) with degeneration lumbar stenosis involving 165 segments were enrolled from April 2015 to June 2017, and treated by full endoscopic uniportal unilateral laminotomy for bilateral decompression. We made an 8-mm incision and used a general-size endoscope (working channel 4.3 mm) to avoid neurological compromise during the demonstration.The visual analogue scale (VAS) results for back pain revealed a significant reduction from preoperative 6.8 ± 2.1 to 1.7 ± 1.7 after 2 years (P0.001). The VAS results for leg pain revealed a significant reduction from preoperative 7.6 ± 1.3 to 1.3 ± 1.6 after 2 years (P0.001). The Oswestry Disability Index showed significant improvement from preoperative 62.0 ± 13.9 to 14.6 ± 15.7 after 2 years (P 0.001). The average operation time was 68.9 ± 10.0 minutes per level. One case had iatrogenic durotomy, 1 case underwent revision surgery due to incomplete decompression, and 2 cases had delayed wound healing.This procedure obtained successful and satisfactory outcomes for patients, and was more feasible for surgeons.

Simultaneous bilateral total knee arthroplasty (SBTKA) increases the rates of procedure-related complications and mortality compared with unilateral TKA. There are no well-defined guidelines for selecting patients to avoid mortality and proposing an upgrade treatment to decrease complication rates. This study aimed to evaluate whether optimal perioperative management could improve the safety of SBTKA. From 2005 to 2017, 1,166 cases of SBTKA were identified from 14,209 TKA procedures. We retrospectively examined the SBTKA patients' demographics, comorbidity profiles, procedure-related complications, and perioperative management during two time periods. Optimal perioperative workup for managing SBTKA significantly decreased the incidences of major complication from 6.2 to 2.4% (p = 0.001) and minor complications from 28.9 to 21.5% (p = 0.004) during period I and period II, respectively. The efficiency of less tourniquet use along with intraarticular tranexamic acid injection was demonstrated by the decreases of hemoglobin (Hb) change in the first 2 days after surgery (p = 0.005) and blood transfusion requirement (p = 0.035) during the SBTKA. Furthermore, the less tourniquet use group had less thigh pain (visual analog scale decreased from 6.0 to 4.2, p = 0.003), shorter duration of hospital stay (decreased from 7.8 to 7.1, p 80 years and with an American Society of Anesthesiologists score of 3. Additionally, hospitalists should consider developing methods for the eligibility, testing, and perioperative monitoring of patients who undergo SBTKA with the aim of avoiding complications and improving outcomes.

Background: Controversy is not uncommon in the diagnosis of discogenic low back pain (DLBP) and in the identification of the location of the pain source for the symptomatic disc in patients with DLBP. Various techniques, from minimally invasive procedures to fusion surgery, are used to treat chronic DLBP, but the clinical outcomes are variable. Percutaneous endoscopic discectomy by transforaminal or interlaminar approach is considered to be an effective method to treat DLBP, but the evidence is limited; the lack of clear evidence may be associated with patient selection and surgical technique. Objectives: The purpose of this study is to evaluate the clinical results of percutaneous endoscopic treatment for annular tear in selected patients with DLBP by using the outside-in technique. Study Design: A prospective study and retrospective observations were performed on 24 consecutive patients with a minimum 2 years of follow-up. This study was approved by the Institutional Review Board (IRB) of Buddhist Dalin Tzu-Chi General Hospital Foundation (IRB number: 10504004) and written informed consent was obtained from all patients. Setting: This research took place within an interventional pain management and spine practice. Methods: Twenty-four consecutive patients with single-level DLBP diagnosed by positive highintensity zone on magnetic resonance imaging, positive provocative discography, and block test underwent a percutaneous endoscopic procedure from January 2014 to December 2015. The transforaminal approach or interlaminar approach was selected according to the location of the annular tear. The torn lesions were visualized directly and treated by puncture and debridement of the inflammatory tissues from the outer annulus fibrosus to the inner nucleus using the outsidein technique. The Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI) score were evaluated before and after surgery. The clinical global outcomes were assessed on the basis of modified MacNab criteria. Results: These patients included 13 men and 11 women with a mean age of 43.8 years (range, 32-55 yrs). There were 15 lesion levels at L4/L5 and 9 lesion levels at L5/S1. Among them, 15 levels were accessed by transforaminal approach and 9 levels by interlaminar approach. No serious complications were observed during the follow-up periods. All except 2 patients experienced significant symptomatic and functional improvements at the 2-year follow-up with a success rate of 91.7%. Limitations: Significant limitations include nonrandom format and small sample size. Future research may focus on controlled prospective studies with larger sample sizes and long-term followup to examine the validity of this protocol. Conclusions: The percutaneous endoscopic procedure provides a safe and effective treatment for selected patients with DLBP. The outside-in technique allows the surgeons to visualize and treat the torn or inflammatory lesions directly, and the success rate is high at 2 years follow-up. Key words: Transforaminal, interlaminar, outside-in technique, endoscopic discectomy, discogenic low back pain

Background: Patients undergoing hemodialysis are prone to cardiac arrests. Methods: This study aimed to develop a risk score to predict in-hospital cardiac arrest (IHCA) in emergency department (ED) patients undergoing emergency hemodialysis. Patients were included if they received urgent hemodialysis within 24 h after ED arrival. The primary outcome was IHCA within three days. Predictors included three domains: comorbidity, triage information (vital signs), and initial biochemical results. The final model was generated from data collected between 2015 and 2018 and validated using data from 2019. Results: A total of 257 patients, including 52 with IHCA, were analyzed. Statistical analysis selected significant variables with higher sensitivity cutoff, and scores were assigned based on relative beta coefficient ratio: K &gt, 5.5 mmol/L (score 1), pH &lt, 7.35 (score 1), oxygen saturation &lt, 85% (score 1), and mean arterial pressure &lt, 80 mmHg (score 2). The final scoring system had an area under the curve of 0.78 (p &lt, 0.001) in the primary group and 0.75 (p = 0.023) in the validation group. The high-risk group (defined as sum scores ≥ 3) had an IHCA risk of 47.2% and 41.7%, while the low-risk group (sum scores &lt, 3) had 18.3% and 7%, in the primary and validation databases, respectively. Conclusions: This predictive score model for IHCA in emergent hemodialysis patients could help healthcare providers to take necessary precautions and allocate resources.

Seismic signals are usually generated during landslides or movement of soil mass due to collisions and friction among the soil particles and masses. The seismic signals will be different when different sliding (movement) types occur. This study discusses the landslide process and seismic signals produced by soil ruptures to understand the nature of the signals, which could help in predicting landslides as well as understanding different landslide processes. Physical model tests were performed to record the seismic signals generated during the sliding processes. The self-potential (SP), pore water pressure (PP), and volumetric water content (VWC) were also measured to assist the interpretation of the failure processes. Based on the characteristics of the seismic signals recorded, three slide types were identified: intermittent slide, successive slide, and single slide. Precursor signals prior to the single slide event were found in both the seismic and SP signals and therefore the monitoring of these two kinds of precursors has the potential for real-world application in landslide prewarning. In addition, the landslide areas of the tests were correlated with Arias intensities (IA) in a linear relationship. The relationship has the potential to be implemented in estimating a landslide’s scale for a fast landslide response decision.

Autogenous bone grafts are the gold standard for interbody fusion implant materials; however, they have several disadvantages. Tantalum (Ta) and titanium (Ti) are ideal materials for interbody cages because of their biocompatibility, particularly when they are incorporated into a three-dimensional (3D) porous structure. We conducted an in vitro investigation of the cell attachment and osteogenic markers of self-fabricated uniform porous Ti (20%, 40%, 60%, and 80%), nonporous Ti, and porous Ta cages (n = 6) in each group. Cell attachment, osteogenic markers, and alkaline phosphatase (ALP) were measured. An in vivo study was performed using a pig-posterior-instrumented anterior interbody fusion model to compare the porous Ti (60%), nonporous Ti, and porous Ta interbody cages in 12 pigs. Implant migration and subsidence, determined using plain radiographs, were recorded before surgery, immediately after surgery, and at 1, 3, and 6 months after surgery. Harvested implants were assessed for bone ingrowth and attachment. Relative to the 20% and 40% porous Ti cages, the 60% and 80% cages achieved superior cellular migration into cage pores. Among the cages, osteogenic marker and ALP activity levels were the highest in the 60% porous Ti cage, osteocalcin expression was the highest in the nonporous Ti cage, and the 60% porous Ti cage exhibited the lowest subsidence. In conclusion, the designed porous Ti cage is biocompatible and suitable for lumbar interbody fusion surgery and exhibits faster fusion with less subsidence compared with porous Ta and nonporous Ti cages.

Surgical site infections after posterior spinal surgery may lead to spondylodiscitis, pseudarthrosis, correction loss, adverse neurological sequelae, sepsis, and poor outcomes if not treated immediately. Infection rates vary depending on the type and extent of operative procedures, use of instrumentation, and patients' risk factors. Image evaluation is crucial for early diagnosis and should be complementary to clinical routes, laboratory survey, and treatment timing. Magnetic resonance imaging detects early inflammatory infiltration into the vertebrae and soft tissues, including hyperemic changes of edematous marrow, vertebral endplate, and abscess or phlegmon accumulation around the intervertebral disk, epidural, and paravertebral spaces. Aggressive surgical treatment can eradicate infection sources, obtain a stable wound closure, decrease morbidity, and restore spinal integrity. Organ/space infection is defined as any body parts opened to manipulate other than superficial/deep incision. Advanced magnetic resonance imaging evaluating abnormal fluid accumulation, heterogenous contrast enhancement of the endplate erosion due to cage/screw infection is categorized to inform a presumptive diagnosis for early implant salvage. However, patients' defense response, infection severity, bacteriology, treatment timing, spinal stability, and available medical and surgical options must be fully considered. Revision surgery is indicated for pseudarthrosis, implant loosening with correction loss, recalcitrant spondylodiscitis, and adjacent segment diseases for infection control.

Controversy is not uncommon in the diagnosis of discogenic low back pain (DLBP) and in the identification of the location of the pain source for the symptomatic disc in patients with DLBP. Various techniques, from minimally invasive procedures to fusion surgery, are used to treat chronic DLBP, but the clinical outcomes are variable. Percutaneous endoscopic discectomy by transforaminal or interlaminar approach is considered to be an effective method to treat DLBP, but the evidence is limited; the lack of clear evidence may be associated with patient selection and surgical technique.The purpose of this study is to evaluate the clinical results of percutaneous endoscopic treatment for annular tear in selected patients with DLBP by using the outside-in technique.A prospective study and retrospective observations were performed on 24 consecutive patients with a minimum 2 years of follow-up. This study was approved by the Institutional Review Board (IRB) of Buddhist Dalin Tzu-Chi General Hospital Foundation (IRB number: 10504004) and written informed consent was obtained from all patients.This research took place within an interventional pain management and spine practice.Twenty-four consecutive patients with single-level DLBP diagnosed by positive high-intensity zone on magnetic resonance imaging, positive provocative discography, and block test underwent a percutaneous endoscopic procedure from January 2014 to December 2015. The transforaminal approach or interlaminar approach was selected according to the location of the annular tear. The torn lesions were visualized directly and treated by puncture and debridement of the inflammatory tissues from the outer annulus fibrosus to the inner nucleus using the outside-in technique. The Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI) score were evaluated before and after surgery. The clinical global outcomes were assessed on the basis of modified MacNab criteria.These patients included 13 men and 11 women with a mean age of 43.8 years (range, 32-55 yrs). There were 15 lesion levels at L4/L5 and 9 lesion levels at L5/S1. Among them, 15 levels were accessed by transforaminal approach and 9 levels by interlaminar approach. No serious complications were observed during the follow-up periods. All except 2 patients experienced significant symptomatic and functional improvements at the 2-year follow-up with a success rate of 91.7%.Significant limitations include nonrandom format and small sample size. Future research may focus on controlled prospective studies with larger sample sizes and long-term follow-up to examine the validity of this protocol.The percutaneous endoscopic procedure provides a safe and effective treatment for selected patients with DLBP. The outside-in technique allows the surgeons to visualize and treat the torn or inflammatory lesions directly, and the success rate is high at 2 years follow-up.Transforaminal, interlaminar, outside-in technique, endoscopic discectomy, discogenic low back pain.

The postoperative infection rates for transforaminal lumbar interbody fusion (TLIF) have ranged from2% to 4%. However, no consensus has been reached on the treatment strategies. TLIF cage preservation or revision surgery for lumbar spine reconstruction are 2 possible treatments. We aimed to determine the most effective method for organ/space infection control.The data from 4923 patients who had undergone TLIF with cage and posterior pedicle-screw instrumentation for spondylolysis or degenerative spondylolisthesis from January 2008 to December 2015 were retrospectively analyzed. Of the 4923 patients, 32 (0.65%) had developed organ/space infection of the interbody cage and were divided into 2 groups: those whose interbody cage was removed for revision (group 1) and those who interbody cage was retained (group 2). We compared the initial management of both groups in terms of age, sex, elapsed time to diagnosis, changes in spinal lordotic angle, visual analog scale score, fusion status, and Kirkaldy-Willis functional outcomes.The 32 patients with organ/space infection had a mean age of 66.3 years and a follow-up period of 23.8 months. Significant differences were observed in the mean elapsed time to diagnosis (P = 0.004), lordotic angle correction at the disease level (P = 0.03), and Kirkaldy-Wallis functional outcomes (P = 0.01). Of the 17 patients undergoing debridement for implant retention, 9 (52.9%) exhibited poor results.The most important factor contributing to TLIF cage retention failure was epidural fibrosis of the previous transforaminal route and biofilm adhesion on interbody devices affecting infection clearance. Thus, we would recommend a combined anterior and posterior approach or the transforaminal route for radical debridement with cage removal and fusion to achieve better clinical outcomes.

Multiple-input and multiple-output (MIMO) scheme can extend the transmission capacity for the light-emitting-diode (LED) based visible light communication (VLC) systems. The MIMO VLC system that uses the mobile-phone camera as the optical receiver (Rx) to receive MIMO signal from the n×n Red–Green–Blue (RGB) LED array is desirable. The key step of decoding this signal is to detect the signal direction. If the LED transmitter (Tx) is rotated, the Rx may not realize the rotation and transmission error can occur. In this work, we propose and demonstrate a novel hierarchical transmission scheme which can reduce the computation complexity of rotation detection in LED array VLC system. We use the n×n RGB LED array as the MIMO Tx. In our study, a novel two dimensional Hadamard coding scheme is proposed. Using the different LED color layers to indicate the rotation, a low complexity rotation detection method can be used for improving the quality of received signal. The detection correction rate is above 95% in the indoor usage distance. Experimental results confirm the feasibility of the proposed scheme.

To explore the intellectual structure of nursing leadership research in the last decade, the most crucial publications, most influential scholars, as well as the correlations among the publications of these scholars were identified. In this study, bibliometric techniques (citation analysis and cocitation analysis) were used to investigate the intellectual pillars of nursing leadership literature. By analyzing 92 394 citations of 1317 articles regarding nursing leadership published from 2003 to 2012 obtained from the Science Citation Index and Social Sciences Citation Index databases, a knowledge network of nursing leadership studies was mapped. The mapping results can be used to help identify the direction of nursing leadership research and provide a valuable tool for researchers to access the literature in this field. In this paper, the problems arising from the struggle to establish nursing leadership were empirically investigated by examining the literature by using citation and cocitation data obtained from Technovation. A brief review of similar bibliometric studies is presented to introduce the approach, accompanied by a description of the data. The principal investigation was a factor analysis that was performed to determine the latent structure underlying the nursing leadership literature. Citation and cocitation are essential research tools for evaluating the core knowledge of an academic field (1), (2). A few studies using bibliometrics to examine leadership research have been published (3), (4), but almost none have reported cocitation analysis in the nursing leadership field. Therefore, conducting this study fills the gap in nursing leadership research by providing a detailed evaluation of applying citation and cocitation to nursing leadership research. The aim of this study was to provide leadership researchers with a unique map to improve their understanding of leadership-related publications and to provide a systematic and objective map of various themes and concepts in the development of the leadership field. The linkages among publications were also identified and their statuses, positions, and contributions to the development of the nursing

ABSTRACT: Study Design. For lumbosacral nonlinear analysis, the characteristics and differences between the load- and range of motion-controlled methods (LCM and RCM) were compared using the numerical approach.Objective. This study aimed to discuss the LCM and RCM problems inherent in method assumption and calculation procedure. A displacement-controlled method (DCM) based on the nodal movement at the lumbosacral top was proposed to offer a more efficient and equivalent comparison between the evaluated models.Summary of Background Data. Both LCM and RCM have been extensively used to evaluate the biomechanical performance of lumbosacral implants. The LCM models were subject to the same loads as the intact model. The ranges of motion (ROMs) of the RCM models were controlled in the same way by iteratively adjusting some of the applied loads. However, the different strategies for adjusting lumbar loads might affect the predicted results and the execution might be inefficient. To the best of the authors' knowledge, the kinematic, mechanical, and computational comparisons between the two methods have still not been extensively investigated.Methods. An intact lumbosacral model was developed and validated with the cadaveric and numerical data of the literature studies. The intact model was then modified as a degenerative model, in which the moderately dehydrated L4-L5 segment was instrumented with transpedicular fixation. Lumbosacral flexion was simulated by ligament interconnection, muscular contraction, and weight compression. One LCM, three RCM, and one DCM models were developed to evaluate their effects on biomechanical results and the computational efficiency of the lumbosacral nonlinear analysis.Results. Both solution feasibility and calculation time were closely related to the loading sequence that was defined as the time curves of the load-incremental control. The calculations of the RCM models were the most time-consuming. The calculation time of the DCM model was about seventeen times faster than that of the RCM counterparts. Aside from the LCM model, the total ROM of the other models could be consistently controlled to the same value as that of the intact model. The intersegmental ROMs of all models were quite comparable. However, the LCM model predicted the least value of the screw stress and averagely 15.6% and 19.9% less than the RCM, and DCM models. In general, the computational efficiency between the models was the most different, followed by the mechanical stress; the kinematic results were the most comparable.Conclusion. The superiority of the computational efficiency of the DCM over its counterparts makes it the improved strategy for executing lumbosacral nonlinear analysis.

Background: Although antituberculosis medication is the first step in the management of skeletal tuberculosis (TB), surgical debridement, biopsy, synovectomy, or arthrodesis may be needed for the definitive diagnosis and treatment of the symptomatic ankle. Methods: Twenty-nine patients with TB around the ankle joint were enrolled during a 23-year period and followed for 73.1 months (range, 30-260 months) after TB was controlled. Among 61 surgical procedures performed in 29 patients, complete resolution of ankle TB was seen in 28 patients. Results: According to Martini and Ouahes classification, radiographic findings of localized osteoporosis were stage I in 4 patients, one or more erosions were stage II in 9 patients, destruction of the whole joint was stage III in 8 patients, and anatomic disorganization and subluxation were stage IV in 8 patients. Functional results were excellent in 6 patients and good in 16 patients, but with talar bone collapse or hindfoot malalignment, a fair result was noted in 6 patients. The diagnostic accuracy rates were 28.5% with aspiration of synovial fluid, 66.7% in histological analysis, and 44.4% in bacteriological analysis. Mixed infection with bacterial flora was noted in 8 patients (27.6%). Conclusions: Ankle TB is easily misdiagnosed and may ultimately involve the peritalar neighboring joints with talar height loss or hindfoot deformity. Successful treatment depends on the extent of disease at presentation, accurate staging, duration of adequate chemotherapy, and optimal surgical intervention. Level of Evidence: Level IV, retrospective case series.

In this paper, an effective music genre classification algorithm using sparse representation based classification (SRC) and wavelet packet transform (WPT) with discrete trigonometric transform (DTT) is developed for improving the classification performance. The first step of the proposed algorithm is to apply moving average filter and Butterworth low-pass filter to partly eliminate the effect of fluctuation in short-term signal. Then one can make use of SRC and WPT with DTT to accurately classify and increase classification performance. Sparse representation based classification has been widely used for music genre classification via the primal-dual algorithm for linear programming to search the most compact representation of the signal in the digital domain. To investigate its performance, the proposed method is validated by comparison with various discrete cosine transform types and classification methods. Various experimental results carried out one the ISMIR 2004 Genre dataset show that the proposed method can achieve higher classification accuracy than other music genre classification methods with the same experimental setup.

STUDY DESIGN The biomechanical effects of disc degeneration and hybrid fixation on the transition and adjacent segments were evaluated using a numerical approach. OBJECTIVE This study aimed to evaluate the rigidity-rising effects of the dehydrated disc and bridged fixator on the kinematic and mechanical redistribution of the transition and adjacent segments. SUMMARY OF BACKGROUND DATA After static fixation, a dynamic fixator can be used to preserve motion and share loads for the transition segments. However, the hybrid use of both static and dynamic fixators and its effects on the biomechanical behavior of the transition and adjacent segments were not investigated extensively. METHODS A nonlinear and osseoligamentous lumbar model from L1 vertebra to S1 vertebrae was developed. Ligament interconnection, muscular contraction, and weight compression were all used to simulate lumbar flexion. The static fixator was instrumented at the degenerative L4-L5 segment and the dynamic fixators (Dynesys system) with different stiffness were subsequently applied to the degenerative or healthy L3-L4 segment. A healthy lumbar model was used as a reference point for further comparison and evaluation. The predicted results were validated with the cadaveric and numerical values of the literature studies. Among the 21 models, the junctional problem at the adjacent (L2/L3 and L5/S1) discs as well as the motion preservation and stress distribution at the transition (L3/L4) disc were compared. RESULTS Static fixation and the degenerative disc deteriorated the junctional problem at adjacent segments. On average, the hybrid fixation of the original Dynesys cord constrained the range of motion (ROM) by 65%. Furthermore, it shared 43% of the stress on the transition disc. However, this resulted in the adjacent discs increasing about 50% ROM and 40% stress. The term "trade-off stiffness" was used to express the concept that the decreased stiffness of the original cord could balance the junctional problem, motion preservation, and load protection of the transition and adjacent segments. The trade-off stiffness of the degenerative transition disc was higher than that of the healthy disc. Compared with the original design, the increased ROM and stress of the adjacent segments can be reduced by about 43% using the trade-off stiffness. CONCLUSION The use of the hybrid fixator should involve a certain trade-off between the protection of the transition segment and the deterioration of the adjacent segments. This trade-off stiffness, which largely depends on both fixator design and disc degeneration, provides the improved rigidity and flexibility of the transition and adjacent segments.

Visible light communication (VLC) using spread spectrum modulation (SSM) and differential signaling (DS), detected by a mobile-phone camera is proposed and demonstrated for the first time to provide high immunity to background ambient light interference. The SSM signal provides the coding gain while the DS scheme enhances the clock recovery particular under high background ambient light. Experiment results confirm the feasibility of the proposed scheme, showing that the proposed system has 6-dB gain comparing with the traditional on–off keying (OOK) modulation under background ambient light of 3000 lux. The direct incident ambient light to the mobile-phone camera is 520 lux.

The Coflex device may provide stability to the surgical segment in extension but does not restore stability in other motion. Recently, a modified version called the Coflex rivet has been developed. The effects of Coflex and Coflex rivet implantation on the adjacent segments are still not clear; therefore, the purpose of this study was to investigate the biomechanical differences between Coflex and Coflex rivet implantation by using finite element analyses. The results show that the Coflex implantation can provide stability in extension, lateral bending, and axial rotation at the surgical segment, and it had no influence at adjacent segments except for extension. The Coflex rivet implantation can provide stability in all motions and reduce disc annulus stress at the surgical segment. Therefore, the higher range of motion and stress induced by the Coflex rivet at both adjacent discs may result in adjacent segment degeneration in flexion and extension.

Ninety-eight pilon fractures associated with ipsilateral distal fibular fracture were included in this study. The pilon fractures were treated by open reduction and plating. The 98 fractures were divided into three groups based on the treatment method of fractured fibula. Group A was composed of 50 fibular fractures treated by open reduction and plate fixation. Group B was composed of 23 fibular fractures treated by open reduction and pin fixation. Group C was composed of 25 fibular fractures treated conservatively by closed reduction. The radiographs were reviewed for adequacy of fracture reduction and posttraumatic arthrosis. At the end of follow-up, the clinical outcomes were evaluated using a rating scale. The three groups were similar in respect to Ruedi type, open fracture grade, and demographics (all p values >0.25). Group A showed a decreasing trend of malunion and ankle arthrosis compared to group C (p = 0.091 and p = 0.099, respectively). Group A had a better clinical outcome than group C (p = 0.008). In addition, group A showed an increasing trend of satisfactory outcome compared to group B (p = 0.096). In conclusion, for pilon fractures associated with ipsilateral fibular fractures, stabilisation of the fractured fibula plays an important role in the decrease of distal tibial malunion and post-traumatic ankle arthrosis as well as improvement of clinical outcomes.

This study employed both mechanical testing and finite element analysis to compare the stiffness variations among different intramedullary nail constructs used in the treatment of distal femoral fractures. Compressive and torsional experiments were conducted on a transversely, as well as an obliquely fractured sawbone femur restored with the retrograde intramedullary nail. Corresponding finite element models were established to evaluate the stress distributions around screw holes. The results showed that a perifracture screw could increase stiffness by 40% for the obliquely fractured femur, but that it played an insignificant role in stiffness improvement for the transverse fracture groups. Moreover, compared to proximal-screw fixation, distal-screw fixation could improve construct stiffness by 20%. The absence of one of the two distal screws would increase the screw-hole stress by 70%. Therefore, the distal screw around the metaphyseal region has a more important stabilizing effect in the femur-nail construct than does the proximal screw. A twisting stress pattern occurs on the unused screw holes of the metaphyseal region and induces a higher risk for fatigue fracture. The locking screw at the fracture site would be most effective only if it passed through the fracture gap to integrate the separated femoral pieces.

Based on the rolling shutter effect of the complementary metal-oxide-semiconductor (CMOS) image sensor, bright and dark fringes can be observed in each received frame. By demodulating the bright and dark fringes, the visible light communication (VLC) data logic can be retrieved. However, demodulating the bright and dark fringes is challenging as there is a high data fluctuation and large extinction ratio (ER) variation in each frame due. Hence proper thresholding scheme is needed. In this work, we propose and compare experimentally three thresholding schemes; including third-order polynomial curve fitting, iterative scheme and quick adaptive scheme. The evaluation of these three thresholding schemes is performed.

Percutaneous vertebroplasty has been established as a safe and effective treatment for compression fractures of osteoporotic vertebrae. Complications of vertebroplasty, such as infection or anterior cement extrusion, are rare. Herein, we report an unusual presentation in an immunocompromised patient with an insidious infection of the disk. This infection resulted in dislodgment of the cement inferiorly and a compression fracture of the adjacent vertebra 6 months after vertebroplasty. We discuss the significance of this case and compare it with 7 others found in the literature.

Although free vascularized fibular bone grafting is a good method for the reconstruction of large bone defects, it might cause morbidity of the donor leg. Progression of ankle osteoarthritis, valgus deformity and instability of the donor leg subsequently leading to arthrodesis has rarely been reported. A 53-year-old man suffered from a left tibial comminuted and Gustilo type IIIb open fracture. A folded free vascularized osteoseptocutaneous flap was harvested from the right fibula and transferred to the left tibial bone defect. After the reconstructive surgery, the patient obtained a solid union of the left tibial shaft uneventfully. Ten years later, he suffered intermittent pain on his right ankle. Plain radiographs revealed progressive tibiotalar osteoarthritis. Right ankle arthrodesis with crossed cannulated screws fixation and osteosynthesis of the fibula to the tibia and talus were performed. However, this procedure failed due to a deep infection and osteomyelitis. A revision of the failed ankle fusion was performed by using a vascularized iliac bone flap to strut the anterolateral aspect of the tibiotalar bone defect. A ventral plate fixation and supplementary onlay bone grafting were applied across the anterior aspect of the tibiotalar joint. At the 2-year follow-up, the patient had no pain and resumed his regular daily activities. Harvesting of the fibula may cause longterm ankle osteoarthritis that requires ankle arthrodesis. In revision arthrodesis a ventral plate fixation and vascularized iliac bone flap may be the treatment of choice, neutralizing the large moment due to the long lever arms.

We demonstrate using solar cell as optical receiver (Rx) for visible light communication (VLC). The solar cell is low cost and can convert the VLC optical signal into electrical signal without external power supply. As the response of the solar cell is very limited; we also propose and demonstrate using pre-distortion to significantly enhance the response of the solar cell Rx. A VLC capacity of 0.4 Mbit/s at bit-error-rate (BER) of 10−9 under wireless transmission distance of 75 cm; and a capacity of 0.3 Mbit/s at BER of 10−9 under wireless transmission distance of 125 cm can be achieved.

Distal femur fractures adjacent to total knee arthroplasty are a rare yet complex problem. Recently, extramedullary locking plate and retrograde intramedullary nail fixations have become popular options, but the complication rates associated with these procedures are 15–20 %. Modified fixations were assessed in an effort to reduce complications from unstable periprosthetic fractures. Using experimental and finite element methods, this study compared the construct behaviours of a locking plate, a retrograde intramedullary nail, and their modifications (a spiral-blade supplemented in an intramedullary nail or a locking plate/allograft hybrid) when subjected to various fracture types, locations, loading conditions, and bony strength. The implanted models were used to assess construct stiffness, fracture micromotion, and implant stress under different osteoporotic conditions. Finally, we collected 40 cases for radiological analysis to indicate the appropriate procedure for treating periprosthetic fractures following total knee arthroplasty. Regardless of the fracture type, femoral constructs fixed with a conventional or spiral-blade supplemented intramedullary nail exhibited higher axial but lower torsional stiffness than those fixed with a locking plate. Torsional deformation occurred if the lower-positioned fracture had no medial support. The locking plate/allograft construct exhibited the highest stiffness and the least micromotion. A review of 40 clinical cases confirmed the above findings regarding the locking plate/allograft construct. The spiral-blade supplement of retrograde intramedullary nail and locking plate/allograft modified constructs significantly stabilizes the unstable fractured gaps. The locking plate/allograft is recommended for the periprosthetic fractures with deficient bone stock and severe osteoporosis to improve alignment and healing potentials.

Despite the proximity of the vertebral bodies and discs to the vascular structures of the retroperitoneum, the association of spinal osteomyelitis and aortic infection is a rare1, easily overlooked, but potentially lethal condition that requires prompt diagnosis and aggressive surgical therapy. The pathogens responsible for concurrent vertebral and aortic lesions include Salmonella species as well as other gram-negative bacilli, mycobacteria, gram-positive cocci, and fungi1-3. A delay in the start of appropriate antimicrobial therapy for infections involving these anatomic sites could result in bone and joint destruction and possibly death. We report the case of an elderly immunocompromised patient who had a mycotic aneurysm caused by Salmonella species. After aneurysmectomy, he experienced persistent back pain and progressive loss of lower-extremity neurological function. Further work up disclosed tuberculous lumbar spondylitis and an epidural abscess in the vicinity of the resected aneurysm. The case of this patient emphasizes the possibility of coexistent infection in vulnerable patients. The pitfalls in diagnosis and management are discussed, to enable clinicians to avoid potentially catastrophic complications. The patient was informed that data concerning the case would be submitted for publication. A seventy-nine-year-old man presented to our emergency service because of fever and chills that he had had for eight days. The history included the use of analgesics and a steroid (20 mg/day of prednisolone) for one year for the treatment of chronic low back pain. On arrival, the patient was febrile (38.4°C), with a blood pressure of 150/90 mm Hg. Physical examination revealed a cushingoid habitus (moon face, truncal obesity, and paper-thin skin), a pulsatile abdominal mass, and low back pain limiting his spinal flexibility. Plain radiographs of the lumbar spine showed multiple traction spurs along the anterior edges of the vertebrae and decreased disc height at L3-L4 without overt evidence …

The long-term results of pilon fractures are rarely documented. The present study evaluated the long-term results related to each fracture pattern of a pilon fracture treated with open reduction and plating. One hundred and twenty-eight pilon fractures with a mean 10-year follow-up were divided into three groups, based on the Ruedi-Allgower classification. Group A was composed of 39 patients with Ruedi-Allgower type I fractures; group B comprised 62 patients with type II fractures; and group C included 27 patients with type III fractures. The radiographs were reviewed for adequacy of fracture reduction and posttraumatic arthrosis. At the end of follow-up, the clinical results were evaluated using a rating scale. Group C had significantly lower excellent and good reduction rates than group A or B (P

This study investigated the release of antibiotics in vivo, from an articulating polymethylmethacrylate (PMMA) spacer used in two-stage revision arthroplasty of infected hip implants. Forty-six patients who underwent two-stage revision hip arthroplasty for infections were managed with an interim PMMA spacer loaded with a high dose of vancomycin and aztreonam. Serum and aliquots of drainage collected after the first-stage surgery, and joint fluid obtained at the time of the second-stage surgery were analyzed for antibiotic concentrations by high performance liquid chromatography and bioactivity by tube dilution bioassay. Following implantation, the highest levels of antibiotics were measured in aliquots of drainage on the first day (vancomycin: 1538.0 +/- 243.6 microg/mL; aztreonam: 1003.5 +/- 323.5 microg/mL), decreasing to 571.9 +/- 169.4 microg/mL for vancomycin and 313.6 +/- 88.3 microg/mL for aztreonam after 7 days. Antibiotic concentrations in serum were very low (vancomycin: 0.58 +/- 0.2 microg/mL, range: 0.1-1.6 microg/mL; aztreonam: 0.46 +/- 0.3 microg/mL, range: 0.1-0.9 microg/mL at 24 h) and there was no systemic adverse effect. At a mean 107 days after the first-stage surgery, the concentrations of antibiotics in joint fluid were well above the minimal inhibitory concentration of most common microorganisms. The released antibiotics were bioactive against the test organisms. Based on the observed results, we confirmed the safety and effectiveness of in vivo drug delivery from antibiotic-impregnated PMMA hip spacers.

The modified Bosworth technique, a reconstructive procedure for the treatment of chronic Achilles tendon ruptures, resolves the problem of the shorter gastrosoleus aponeurosis.

Juvenile xanthogranuloma (JXG) is a self-limited cutaneous lesion that most often occurs in infancy. Approximately 10% to 30% of JXGs occur in adult patients, where most cases present as cutaneous papulonodular lesions, with only rare cases involving extracutaneous sites. Intramuscular JXG is extremely rare and has received little attention. On review of the literature, all of the 6 previously reported intramuscular JXGs were noted in the pediatric population. The authors hereby describe a case of adult intramuscular JXG that occurred in a woman who initially had a dermal JXG in the nasal skin at the age of 48 years and then developed a slow-growing painless intramuscular JXG in the right forearm 4 years later. Both the dermal and intramuscular lesions revealed similar histologic features and consisted of diffuse infiltrates of histiocytes with eosinophilic and foamy cytoplasm, lymphocytes, eosinophils, and Touton giant cells in varying proportions. However, central fibrosis and a focal storiform arrangement of spindled fibroblast-like cells in the intramuscular lesion resulted in a histologic pattern reminiscent of a fibrous histiocytoma. Immunohistochemically, the intramuscular JXG was positive for CD68, factor XIIIa, CD31, and vimentin. This case underscores the fact that intramuscular JXG can also involve adult patients and its morphologic variation is more likely to be time dependent rather than site specific or age related.

The current study aims to investigate the relationships among social support, thriving at work, and change-oriented organizational citizenship behavior in the Taiwan’s hotel workplace context. 276 valid data collected from employees in Taiwan’s hotel were used to proof the research hypotheses through structural equation model. Empirical results demonstrated that the proposed model fits well. Findings also showed that social support was positive related to employees’ thriving at work and change-oriented organizational citizenship behavior; employees’ thriving at work was positively related to employees’ change-oriented organizational citizenship behavior. This study highlighted that employees’ thriving at work mediated the relationship between social support and change-oriented organizational citizenship behavior. Theoretical and practice implications, limitations, and suggestions for future were offered.

Blunt chest trauma with tracheoesophageal perforation is an unusual and potentially catastrophic event. More than 60% of patients with these injuries-which are often associated with multiple major vessel tears, cardiopulmonary tamponade, or tension pneumothorax-die before reaching a hospital or during resuscitation1. Tracheoesophageal perforations in the cervical region are most often caused by penetrating injuries or by blunt trauma causing cervical hyperextension. Such injuries are less frequently recognized in the thoracic area2,3. Combined perforations of the "common weak wall" of the trachea and esophagus in the upper thoracic region can present challenges such as airway obstruction, septic pleuromediastinitis, and unstable hemodynamics. Furthermore, concurrent vertebral fracture with spinal cord damage can confound the course of management. We report a case of a motorcyclist with an upper thoracic spine fracture associated with incomplete spinal cord damage and a tracheoesophageal perforation. A twenty-year-old male motorcycle rider was hit by an automobile and struck the road, landing on the upper part of his back. In the emergency room, he was found to be in shock and unconscious and to have severe neck swelling, subcutaneous emphysema, and dyspnea. A supine chest radiograph revealed mediastinal widening, a right pneumothorax (Fig. 1, A ), and fractures of the right third through sixth ribs. A thoracostomy yielded abundant air, 200 mL of blood, and food debris. Neurological assessment of the limbs was impossible because the patient was unconscious (a score of 7 of 15 on the Glasgow coma scale4 ). However, a computed tomographic evaluation was negative for intracranial hemorrhage. Subsequent supine radiographs of the chest showed a persistent air leak, massive subcutaneous emphysema, and a pneumomediastinum (Fig. 1, B ), but no bone abnormalities were noted on radiographs of the cervical spine. Because the patient was having respiratory difficulty, an endotracheal …