Deep learning-based facial analysis for predicting difficult videolaryngoscopy: a feasibility study

While videolaryngoscopy has resulted in better overall success rates of tracheal intubation, airway assessment is still an important prerequisite for safe airway management. This study aimed to create an artificial intelligence model to identify difficult videolaryngoscopy using a neural network. Baseline characteristics, medical history, bedside examination and seven facial images were included as predictor variables. ResNet-18 was introduced to recognise images and extract features. Different machine learning algorithms were utilised to develop predictive models. A videolaryngoscopy view of Cormack-Lehane grade of 1 or 2 was classified as 'non-difficult', while grade 3 or 4 was classified as 'difficult'. A total of 5849 patients were included, of whom 5335 had non-difficult and 514 had difficult videolaryngoscopy. The facial model (only including facial images) using the Light Gradient Boosting Machine algorithm showed the highest area under the curve (95%CI) of 0.779 (0.733-0.825) with a sensitivity (95%CI) of 0.757 (0.650-0.845) and specificity (95%CI) of 0.721 (0.626-0.794) in the test set. Compared with bedside examination and multivariate scores (El-Ganzouri and Wilson), the facial model had significantly higher predictive performance (p < 0.001). Artificial intelligence-based facial analysis is a feasible technique for predicting difficulty during videolaryngoscopy, and the model developed using neural networks has higher predictive performance than traditional methods.

Orthopedic mechanism analysis of growing rod distraction for early-onset scoliosis based on 3D morphological parameters

Traditional growing rod (TGR) provides a corrective moment for deformed segments to straighten the spine, whose clinical efficacy has proven positive and growth-friendly. However, an insufficient understanding of orthopedic mechanisms can affect the development of clinical strategies. This research attempts to analyze the spine that has undergone four distraction operations: exploring the spinal orthopedic mechanism, including alignment, growth, and morphology. In this study, the spinal morphology curves were illustrated in three human planes to exhibit the changes in spinal alignment. The spinal growth characteristics were measured to discuss the unsynchronized and diminishing growth rate. The spinal deformations were evaluated to indicate asymmetric growth. As a result, the spinal alignment changes indicated the orthopedic process improved, but the re-unbalance occurred after multiple distractions. Then, unsynchronized growth existed in the superior and inferior segments, and the growth rate over every distraction diminished. Finally, asymmetric growth was indicated as the axial/circumferential growth ratio getting greater and the cuneate level approaching normal. Accordingly, a TGR is growth-friendly, but combining the osteotomy fusion of lumbar segments for severe early-onset scoliosis may be an excellent choice to solve the insufficient corrective stimulation. Regarding the distraction process, reshaping before the final fusion can fix the balance loss, and a prolonged distraction frequency fits the law of diminishing return. In conclusion, studying orthopedic mechanisms based on morphological measurement can guide clinical strategy optimization.

Effects of dynamic and rigid implantation on biomechanical characteristics of different sagittal alignment lumbar after single- or double-level spinal fixations: a finite-element modeling study

BACKGROUND

Although it is critical to understand the accelerated degeneration of adjacent segments after fusion, the biomechanical properties of the spine have not been thoroughly studied after various fusion techniques. This study investigates whether four Roussouly's sagittal alignment morphotypes have different biomechanical characteristics after different single- or double-level spinal fixations.

METHODS

The parametric finite element (FE) models of Roussouly's type (1-4) were developed based on the radiological data of 625 Chinese community population. The four Roussouly's type models were reassembled into four fusion models: single-level L4-5 Coflex fixation model, single-level L4-5 Fusion (pedicle screw fixation) model, double-level Coflex (L4-5) + Fusion (L5-S1) model, and double-level Fusion (L4-5) + Fusion (L4-5) model. A pure moment of 7.5 Nm was applied to simulate the physiological activities of flexion, extension, lateral bending and axial rotation.

RESULTS

Both single-level and double-level spinal fixation had the greatest effect on lumbar range of motion, disc pressure, and annulus fibrosis stress in flexion, followed by lateral bending, extension, and axial rotation. In all models, the upper adjacent segment was the most influenced by the implantation and bore the most compensation from the fixed segment. For Type 2 lumbar, the L4-L5 Coflex effectively reduced the disc pressure and annulus fibrosis stress in adjacent segments compared to the L4-L5 Fusion. Similarly, the L4-L5 Coflex offered considerable advantages in preserving the biomechanical properties of adjacent segments for Type 1 lumbar. For Type 4 lumbar, the L4-L5 Coflex did not have superiority over the L4-L5 Fusion, resulting in a greater increase in range of motion at adjacent segments in flexion and extension. The difference between the two fixations was not apparent in Type 3 lumbar. Compared to the single-level Fusion, the changes in motion and mechanics of the lumbar increased after both the double-level Coflex + Fusion and Fusion + Fusion fixations, while the differences between two double-level fixation methods on adjacent segments of the four lumbar models were similar to that of the single-level fixation.

CONCLUSION

Type 3 and Type 4 lumbar have good compensatory ability and therefore allow for a wider range of surgical options, whereas surgical options for small lordotic Type 1 and Type 2 lumbar are more limited and severe.

Investigations into the effects of scaffold microstructure on slow-release system with bioactive factors for bone repair

In recent years, bone tissue engineering (BTE) has played an essential role in the repair of bone tissue defects. Although bioactive factors as one component of BTE have great potential to effectively promote cell differentiation and bone regeneration, they are usually not used alone due to their short effective half-lives, high concentrations, etc. The release rate of bioactive factors could be controlled by loading them into scaffolds, and the scaffold microstructure has been shown to significantly influence release rates of bioactive factors. Therefore, this review attempted to investigate how the scaffold microstructure affected the release rate of bioactive factors, in which the variables included pore size, pore shape and porosity. The loading nature and the releasing mechanism of bioactive factors were also summarized. The main conclusions were achieved as follows: i) The pore shapes in the scaffold may have had no apparent effect on the release of bioactive factors but significantly affected mechanical properties of the scaffolds; ii) The pore size of about 400 μm in the scaffold may be more conducive to controlling the release of bioactive factors to promote bone formation; iii) The porosity of scaffolds may be positively correlated with the release rate, and the porosity of 70%-80% may be better to control the release rate. This review indicates that a slow-release system with proper scaffold microstructure control could be a tremendous inspiration for developing new treatment strategies for bone disease. It is anticipated to eventually be developed into clinical applications to tackle treatment-related issues effectively.

Biomechanical comparative analysis of conventional pedicle screws and cortical bone trajectory fixation in the lumbar spine: An in vitro and finite element study

Numerous screw fixation systems have evolved in clinical practice as a result of advances in screw insertion technology. Currently, pedicle screw (PS) fixation technology is recognized as the gold standard of posterior lumbar fusion, but it can also have some negative complications, such as screw loosening, pullout, and breakage. To address these concerns, cortical bone trajectory (CBT) has been proposed and gradually developed. However, it is still unclear whether cortical bone trajectory can achieve similar mechanical stability to pedicle screw and whether the combination of pedicle screw + cortical bone trajectory fixation can provide a suitable mechanical environment in the intervertebral space. The present study aimed to investigate the biomechanical responses of the lumbar spine with pedicle screw and cortical bone trajectory fixation. Accordingly, finite element analysis (FEA) and in vitro specimen biomechanical experiment (IVE) were performed to analyze the stiffness, range of motion (ROM), and stress distribution of the lumbar spine with various combinations of pedicle screw and cortical bone trajectory screws under single-segment and dual-segment fixation. The results show that dual-segment fixation and hybrid screw placement can provide greater stiffness, which is beneficial for maintaining the biomechanical stability of the spine. Meanwhile, each segment's range of motion is reduced after fusion, and the loss of adjacent segments' range of motion is more obvious with longer fusion segments, thereby leading to adjacent-segment disease (ASD). Long-segment internal fixation can equalize total spinal stresses. Additionally, cortical bone trajectory screws perform better in terms of the rotation resistance of fusion segments, while pedicle screw screws perform better in terms of flexion-extension resistance, as well as lateral bending. Moreover, the maximum screw stress of L4 cortical bone trajectory/L5 pedicle screw is the highest, followed by L45 cortical bone trajectory. This biomechanical analysis can accordingly provide inspiration for the choice of intervertebral fusion strategy.

Adding sacral anchors through an S1 alar screw and multirod construct as a strategy for lumbosacral junction augmentation: an in vitro comparison to S1 pedicle screws alone with sacroiliac fixation

OBJECTIVE

Achieving solid fusion of the lumbosacral junction continues to be a challenge in long-segment instrumentation to the sacrum. The purpose of this study was to test the condition of adding sacral anchors through an S1 alar screw (S1AS) and multirod construct relative to using S1 pedicle screws (S1PSs) alone with sacroiliac fixation in lumbosacral junction augmentation.

METHODS

Seven fresh-frozen human lumbar-pelvic spine cadaveric specimens were tested under nondestructive moments (7.5 Nm). The ranges of motion (ROMs) in extension, flexion, left and right lateral bending (LB), and axial rotation (AR) of instrumented segments (L3-S1); the lumbosacral region (L5-S1); and the adjacent segment (L2-3) were measured, and the axial construct stiffness (ACS) was recorded. The testing conditions were 1) intact; 2) bilateral pedicle screw (BPS) fixation at L3-S1 (S1PS alone); 3) BPS and unilateral S2 alar iliac screw (U-S2AIS) fixation; 4) BPS and unilateral S1AS (U-S1AS) fixation; 5) BPS and bilateral S2AIS (B-S2AIS) fixation; and 6) BPS and bilateral S1AS (B-S1AS) fixation. Accessory rods were used in testing conditions 3-6.

RESULTS

In all directions, the ROMs of L5-S1 and L3-S1 were significantly reduced in B-S1AS and B-S2AIS conditions, compared with intact and S1PS alone. There was no significant difference in reduction of the ROMs of L5-S1 between B-S1ASs and B-S2AISs. Greater decreased ROMs of L3-S1 in extension and AR were detected with B-S2AISs than with B-S1ASs. Both B-S1ASs and B-S2AISs significantly increased the ACS compared with S1PSs alone. The ACS of B-S2AISs was significantly greater than that of B-S1ASs, but with greater increased ROMs of L2-3 in extension.

CONCLUSIONS

Adding sacral anchors through S1ASs and a multirod construct was as effective as sacropelvic fixation in lumbosacral junction augmentation. The ACS was less than the sacropelvic fixation but with lower ROMs of the adjacent segment. The biomechanical effects of using S1ASs in the control of long-instrumented segments were moderate (better than S1PSs alone but worse than sacropelvic fixation). This strategy is appropriate for patients requiring advanced lumbosacral fixation, and the risk of sacroiliac joint violation can be avoided.

Biomechanical comparative analysis of effects of dynamic and rigid fusion on lumbar motion with different sagittal parameters: An in vitro study

Background: Although the management of the lumbar disease is highly dependent on the severity of the patient’s condition, optimal surgical techniques to reduce the risk of adjacent degeneration disease (ADS) remain elusive. Based on in vitro biomechanical tests of the cadaver spine, this study aimed to comparatively analyze the kinematic responses of the spine with dynamic and rigid fixations (i.e., Coflex fixation and posterolateral fusion) after single-or double-level lumbar fusion in daily activities.

Methods: Six human lumbar specimens (L1-S1) were selected for this experiment, and the sagittal parameters of each lumbar specimen were measured in the 3D model. The specimens were successively reconstructed into five groups of models: intact model, single-level L4-5 Coflex fixation model, single-level L4-5 Fusion (posterior pedicle screw fixation) model, double-level L4-5 Coflex + L5-S1 Fusion model; and double-level L4-5 Fusion + L5-S1 Fusion model. The pure moment was applied to the specimen model to simulate physiological activities in daily life through a custom-built robot testing device with an optical tracking system.

Results: For single-level lumbar fusion, compared to the traditional Fusion fixation, the Coflex dynamic fixation mainly restricted the extension of L4-L5, partially retained the range of motion (ROM) of the L4-L5 segment, and reduced the motion compensation of the upper adjacent segment. For the double-level lumbar fixation, the ROM of adjacent segments in the Coflex + Fusion was significantly decreased compared to the Fusion + Fusion fixation, but there was no significant difference. In addition, PT was the only sagittal parameter of the preoperative lumbar associated with the ROM under extension loading. The Coflex fixation had little effect on the original sagittal alignment of the lumbar spine.

Conclusion: The Coflex was an effective lumbar surgical technique with a less altering kinematic motion of the lumbar both at the index segment and adjacent segments. However, when the Coflex was combined with the fusion fixation, this ability to protect adjacent segments remained elusive in slowing the accelerated degradation of adjacent segments.

Biomechanical responses of human lumbar spine and pelvis according to the Roussouly classification

Background

Few studies have analyzed the different biomechanical properties of the lumbar with various morphological parameters, which play an important role in injury and degeneration. This study aims to preliminarily investigate biomechanical characteristics of the spine with different sagittal alignment morphotypes by using finite element (FE) simulation and in-vitro testing.

Methods

According to the lumbar-pelvic radiographic parameters of the Chinese population, the parametric FE models (L1-S1-pelvis) of Roussouly’s type (1–4) were validated and developed based on the in-vitro biomechanical testing. A pure moment of 7.5 Nm was applied in the three anatomical planes to simulate the physiological activities of flexion, extension, left-right lateral bending and left-right axial rotation.

Results

The sagittal configuration of four Roussouly’s type models had a strong effect on the biomechanical responses in flexion and extension. The apex of the lumbar lordosis is a critical position where the segment has the lowest range of motion among all the models. In flexion-extension, type 3 and 4 models with a good lordosis shape had a more uniform rotation distribution at each motor function segment, however, type 1 and 2 models with a straighter spine had a larger proportion of rotation at the L5-S1 level. In addition, type 1 and 2 models had higher intradiscal pressures (IDPs) at the L4-5 segment in flexion, while type 4 model had larger matrix and fiber stresses at the L5-S1 segment in extension.

Conclusion

The well-marched lordotic type 3 lumbar had greater stability, however, a straighter spine (type 1 and 2) had poor balance and load-bearing capacity. The hypolordotic type 4 model showed larger annulus fiber stress. Therefore, the sagittal alignment of Roussouly’s type models had different kinetic and biomechanical responses under various loading conditions, leading to different clinical manifestations of the lumbar disease.

Kinematic and biomechanical responses of the spine to distraction surgery in children with early onset scoliosis: A 3-D finite element analysis

Periodical and consecutive distraction is an effective treatment for severe early onset scoliosis (EOS), which enables the spinal coronal and sagittal plane deformity correction. However, the rate of rod fractures and postoperative complications was still high mainly related to the distraction process. Previous studies have primarily investigated the maximum safe distraction force without a rod broken, neglecting the spinal re-imbalance and distraction energy consumption, which is equally vital to evaluate the operative value. This study aimed to reveal the kinematic and biomechanical responses occurring after spinal distraction surgery, which were affected by traditional bilateral fixation. The spinal models (C6-S1) before four distractions were reconstructed based on CT images and the growing rods were applied with the upward displacement load of 0–25 mm at an interval of 5 mm. Relationships between the distraction distance, the distraction force and the thoracic and lumbar Cobb angle were revealed, and the spinal displacement and rotation in three-dimensional directions were measured. The spinal overall imbalance would also happen during the distraction process even under the safe force, which was characterized by unexpected cervical lordosis and lateral displacement. Additionally, the law of diminishing return has been confirmed by comparing the distraction energy consumption in different distraction distances, which suggests that more attention paid to the spinal kinematic and biomechanical changes is better than to the distraction force. Notably, the selection of fixed segments significantly impacts the distraction force at the same distraction distance. Accordingly, some results could provide a better understanding of spinal distraction surgery.

Influence of Sagittal Lumbopelvic Morphotypes on the Range of Motion of Human Lumbar Spine: An In Vitro Cadaveric Study

Background: Although spinopelvic radiographs analysis is the standard for a pathological diagnosis, it cannot explain the activities of the spine in daily life. This study investigates the correlation between sagittal parameters and spinal range of motion (ROM) to find morphological parameters with kinetic implications. Methods: Six L1–S1 human lumbar specimens were tested with a robotic testing device. Eight sagittal parameters were measured in the three-dimensional model. Pure moments were applied to simulate the physiological activities in daily life. Results: The correlation between sagittal parameters and the ROM was moderate in flexion and extension, but weak in lateral bending and rotation. In flexion–extension, the ROM was moderately correlated with SS and LL. SS was the only parameter correlated with the ROM under all loading conditions. The intervertebral rotation distribution showed that the maximal ROM frequently occurred at the L5–S1 segment. The minimal ROM often appeared near the apex point of the lumbar. Conclusion: Sagittal alignment mainly affected the ROM of the lumbar in flexion and extension. SS and apex may have had kinetic significance. Our findings suggest that the effect of sagittal parameters on lumbar ROM is important information for assessing spinal activity.

Effects of Growing Rod Technique with Different Surgical Modes and Growth Phases on the Treatment Outcome of Early Onset Scoliosis: A 3-D Finite Element Analysis

Early onset scoliosis (EOS) is emerging as a serious threat to children’s health and is the third largest threat to their health after myopia and obesity. At present, the growing rod technique (GRT), which allows patients to regain a well-balanced sagittal profile, is commonly considered as an invasive surgical procedure for the treatment of EOS. However, the risk of postoperative complications and instrumentation breakage remains high, which is mainly related to the choice of fixed mode. Several authors have studied primary stability and instrumentation loads, neglecting the mechanical transmission of the spinal long-segment model in different growth phases, which is fundamental to building a complete biomechanical environment. The present study aimed to investigate the kinematic and biomechanical properties that occur after GRT, across the long spinal structure and the posterior instrumentation, which are affected by unilateral or bilateral fixation. Accordingly, spinal segments (C6-S1) were loaded under flexion (Flex), extension (Ext), left lateral bending (LB), right lateral bending (RB), left torsion (LT), and right torsion (RT) using 11 established spinal models, which were from three growth phases. The stress distribution, spinal and intervertebral range of motion (ROM), counter torque of the vertebra, and bracing force on the rods were measured. The results showed that bilateral posterior fixation (BPF) is more stable than unilateral posterior fixation (UPF), at the expense of more compensations for the superior adjacent segment (SAS), especially when the superior fixed segment is closer to the head. Additionally, the bracing force of the instrumentation on the spine increases as the Cobb angle decreases. Accordingly, this biomechanical analysis provides theoretical suggestions for the selection of BPF or UPF and fixed segments in different growing phases.

The effects of gastric cancer interstitial fluid on tumors based on traditional Chinese medicine 'phlegm' theory and the investigation on the mechanism through microRNA-21 regulation

This study aimed to investigate the effects of gastric cancer interstitial fluid (GCIF) on tumors and explore the possible mechanism of Xiaotan Sanjie decoction (XTSJ) on treatment of gastric cancer from the view of regulating microRNA-21 (miR-21) expression. The GCIF was extracted and identified by measuring the levels of interleukin-8 (IL-8), intercellular adhesion molecule 1 (ICAM-1) and miR-21. The effects of GCIF on the proliferation of SGC-7901 cells and tumor growing were assessed by cell counting kit-8 (CCK-8) assay and subcutaneously transplanted tumor-bearing nude mice model, respectively. Additionally, inhibition effect of XTSJ decoction on proliferation of SGC-7901 cells intervened by GCIF were assessed in vitro and anti-cancer effect of it was further assessed using orthotopic transplanted tumor-bearing nude mice model. The concentration of SGC-7901 gastric cancer cells were dependent on the concentration of the added GCIF. After 72 hours of continuous culture, the interstitial fluid had an obvious proliferative effect on the SGC-7901 tumor cells, which was the most significant in the high concentration group. XTSJ decoction could inhibit the growth-promoting effect (P < 0.01) of GCIF on gastric cancer cells. Intervention of the GCIF might promote the growth (P < 0.05) of the subcutaneously transplanted tumors in nude mice and decrease the net weight of the tumor-bearing nude mice (P < 0.05) after tumor removal. The GCIF was able to up-regulate the expression (P < 0.001) of miR-21 in the subcutaneously transplanted tumors. XTSJ decoction could downregulate the expression (P < 0.05) of miR-21 in SGC-7901 orthotopically transplanted tumors. XTSJ decoction can inhibit the multiplicative effect of GCIF on gastric cancer cells, growth of gastric tumor and promotion effect of GCIF on tumors, probably due to the down-regulating miR-21 expression in tumor tissues.

Applications of Carbon Nanotubes in Bone Tissue Regeneration and Engineering: Superiority, Concerns, Current Advancements, and Prospects

With advances in bone tissue regeneration and engineering technology, various biomaterials as artificial bone substitutes have been widely developed and innovated for the treatment of bone defects or diseases. However, there are no available natural and synthetic biomaterials replicating the natural bone structure and properties under physiological conditions. The characteristic properties of carbon nanotubes (CNTs) make them an ideal candidate for developing innovative biomimetic materials in the bone biomedical field. Indeed, CNT-based materials and their composites possess the promising potential to revolutionize the design and integration of bone scaffolds or implants, as well as drug therapeutic systems. This review summarizes the unique physicochemical and biomedical properties of CNTs as structural biomaterials and reinforcing agents for bone repair as well as provides coverage of recent concerns and advancements in CNT-based materials and composites for bone tissue regeneration and engineering. Moreover, this review discusses the research progress in the design and development of novel CNT-based delivery systems in the field of bone tissue engineering.

Biomechanical effects of posterior pedicle fixation techniques on the adjacent segment for the treatment of thoracolumbar burst fractures: a biomechanical analysis

Posterior pedicle fixation technique is a common method for treating thoracolumbar burst fractures, but the effect of different fixation techniques on the postoperative spinal mechanical properties has not been clearly defined, especially on adjacent segments. A finite element model of T10-L2 with moderate T12 vertebra burst fracture was constructed to investigate biomechanical behavior of three posterior pedicle screw fixation techniques. Compared with traditional short-segment 4 pedicle screw fixation (TS-4) and intermediate long-segment 6 pedicle screw fixation (IL-6), mono-segment 4 pedicle screw fixation (MS-4) provides a safer surgical selection to prevent the secondary degeneration of adjacent segments in the long-term.

Fiber-reinforced scaffolds in soft tissue engineering

Soft tissue engineering has been developed as a new strategy for repairing damaged or diseased soft tissues and organs to overcome the limitations of current therapies. Since most of soft tissues in the human body are usually supported by collagen fibers to form a three-dimensional microstructure, fiber-reinforced scaffolds have the advantage to mimic the structure, mechanical and biological environment of natural soft tissues, which benefits for their regeneration and remodeling. This article reviews and discusses the latest research advances on design and manufacture of novel fiber-reinforced scaffolds for soft tissue repair and how fiber addition affects their structural characteristics, mechanical strength and biological activities in vitro and in vivo. In general, the concept of fiber-reinforced scaffolds with adjustable microstructures, mechanical properties and degradation rates can provide an effective platform and promising method for developing satisfactory biomechanically functional implantations for soft tissue engineering or regenerative medicine.

[Effects of tetrahydrobiopterin on the angiogenesis in hepatocellular carcinoma]

Objective: To investigate the effect and mechanism of tetrahydrobiopterin (BH4) on the angiogenesis in hepatocellular carcinoma (HCC). Methods: BALB/c-nu mice were subcutaneously injected with HepG-2 cells and randomly divided into control and BH4 groups. The BH4 group and control group received 20 mg/kg BH4 or saline by intraperitoneal injection daily for two weeks, respectively. The level of BH4 was measured by high performance liquid chromatography (HPLC), the level of nitric oxide (NO) was measured by Griess test array, the transcriptional level of K-ras was measured by quantitative RT-PCR, and the protein expressions of guanosine triphosphate cyclohydrolase Ⅰ(GTPCH), endothelial nitric oxide synthase (eNOS), phospho-Akt and Akt were determined by Western blot. Results: BH4 level in the tumor tissues of BH4 group was (0.24±0.02) μg/ml, significantly higher than the (0.17±0.01) μg/ml in the control group (P<0.01). The level of NO in the tumor tissues of BH4 group was (51.44±2.90) mmol/L, significantly higher than the (24.77±0.54) mmol/L in the control group (P<0.01). The tumor volume of BH4 group was (191.05±8.70) mm3, significantly higher than the (103.10±5.03) mm3 in the control group (P<0.01). The expressions of CD34, K-ras, phospho-eNOS, phospho-Akt and GTPCH were significantly up-regulated in the tumor tissues of BH4 group when compared with those of the control group (P<0.01). Conclusions: BH4 recognized as an essential cofactor of eNOS can increase tumor-produced NO by activating the wild-type Ras-PI3K/Akt pathway, thus induces angiogenesis. This might provide a novel and promising way to control the progression of hepatocellular carcinoma through targeting BH4 synthesis pathway and inhibiting angiogenesis.

Aggravation of spinal cord compromise following new osteoporotic vertebral compression fracture prevented by teriparatide in patients with surgical contraindications

Patients with spinal cord deficits following new unstable osteoporotic compression fracture and surgical contraindications were considered to receive conservative treatment. Teriparatide was better than alendronate at improving bone mineral density and bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

INTRODUCTION

This study compared the preventive effects of teriparatide and alendronate on aggravation of spinal cord compromise following new unstable osteoporotic vertebral compression fracture (OVCF) in patients with surgical contraindications.

METHODS

This was a 12-month, randomized, open-label study of teriparatide versus alendronate in 49 patients with new unstable OVCF and surgical contraindications. Neurological function was evaluated using modified Japanese Orthopedic Association (mJOA) score (11-point scale, the maximum score of 11 implies normalcy). Visual analog scale (VAS) scores, kyphotic angles, anterior-border heights and diameters of the spinal canal of the fractured vertebrae, any incident of new OVCFs (onset of OVCF during follow-up), spine bone mineral density (BMD), and serum markers of bone resorption and bone formation were also examined at baseline and 1, 3, 6, and 12 months after initiation of the medication regimen.

RESULTS

At 12 months, mean mJOA score had improved in the teriparatide group and decreased in the alendronate group. Mean concentrations of bone formation and bone resorption biomarkers, mean spine BMD, and mean anterior-border height and spinal canal diameter of the fractured vertebrae were significantly greater in the teriparatide group than in the alendronate group. Mean VAS score, mean kyphotic angle of the fractured vertebrae, and incidence of new OVCFs were significantly smaller in the teriparatide group than in the alendronate group.

CONCLUSIONS

In patients with neurological deficits following new unstable OVCF and with surgical contraindications, teriparatide was better than alendronate at improving the BMD and the bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

[Biomechanical study on the effect of the length of cervical anterior fusion on adjacent levels]

OBJECTIVE

To study the effect of length of cervical anterior fusion on adjacent levels by Biomechanical test.

METHODS

Six fresh-frozen human cervical specimens were used in this study. The specimens were tested in flexion, extension, bending and rotation on a spine 3D test system. The specimens were tested intact and then underwent a single-level anterior cervical discectomy and fusion (ACDF) at the C4-5 first, a double-level fusion at the C4-6, and finally extended to triple-level at the C4-7, Based on a hybrid test method. Changes in overall range of motion (ROM), segmental motion and facet joints pressure during flexion, extension, bending and rotation were measured and statistically analyzed.

RESULTS

The overall ROM of the entire spinal construct decreased progressively as the single-level fixation extending to 2-level and 3-level (P < 0.05). A progressive increase in ROM above (C3-4) the fused motion segment units (MSUs) was found during flexion, extension and bending (P < 0.05). In bending and extension, a same result was recorded on the average pressure and max pressure of C3-4 facet joints (P < 0.05).

CONCLUSIONS

This study has demonstrated that the biomechanics at adjacent levels to a cervical spine fusion are altered and that there was progressively increased adjacent segment motion and stress as a single-level ACDF extended to a 3-level fusion, which might lead to the acceleration of adjacent segment degeneration.

[Key technologies and implementation of the medical equipment road transportation simulation platform based on 6-DOF parallel robots]

In view of the shortage of medical equipment road transportation simulation platform, we put forward a road transportation simulation method based on 6-DOF parallel robots. A 3D road spectrum model was built by the improvement of the harmonic superposition method. The simulation model was then compared with the standard model to verify its performance. Taking the road spectrum as the excitation, we could get the robot motion data to control the parallel robot through the S-shaped linear interpolation of the absolute position. It can simulate the movement of vehicles with different speed under various road conditions efficiently and accurately.

[A design of simple ventilator control system based on LabVIEW]

This paper designed a ventilator control system to control proportional valves and motors. It used LabVIEW to control the object mentioned above and design ,validate, evaluate arithmetic, and establish hardware in loop platform. There are two system' s hierarchies. The high layer was used to run non-real time program and the low layer was used to run real time program. The two layers communicated through TCP/IP net. The program can be divided into several modules, which can be expanded and maintained easily. And the harvest in the prototype designing can be seamlessly used to embedded products. From all above, this system was useful in employing OEM products.

The effect of methadone on the QTc interval in advanced cancer patients

9064

Background: Methadone (ME) has been used increasingly for pain control and for maintenance in drug addiction programs. Its use is increasing in cancer patients (pts), mainly as part of opioid rotation. Some recent reports suggest that ME may prolong QTc interval and cause torsade de pointes in pts on high dose ME. The purpose of our study was to determine the effect of initiation of ME on QTc interval in pts with cancer pain. Methods: We enrolled 101 pts in this prospective study. These pts had never been on ME before. Pts were followed clinically and electrocardiographically for QTc changes from baseline. EKG was obtained at baseline (QTc0), 2 (QTc2), 4 (QTc4), and 8 (QTc8) weeks. We recorded other contributing factors for QTc prolongation such as medication interactions with ME and electrolyte disturbances. QTc is prolongation is defined as > 430 ms in males and > 450 ms in females. In our study, significant QTc prolongation was defined as = 10% increase from baseline or QTc = 500 msec. Results: 74 pts (73%) had normal QTc (group A) and 27 pts (27%) had prolonged QTc (group B) at baseline. Significant increase in QTc in group A males occured in 1 of 16 (6%) at week 2, 2 of 10 (20%) at week 4, and 0 of 8 (0%) at week 8. Significant increase in QTc in group A females occured in 3 of 32 (10%) at week 2, 1 of 21 (5%) at week 4, and 0 of 12 (0%) at week 8. These pts had multiple contributing factors for QTc prolongation. QTc > reference for males occured in 6 of 16 (37%) at week 2, 4 of 10 (40%) at week 4, and 1 of 8 (12%) at week 8; in females, 1 of 32 (3%) at week 2, 3 of 21 (14%) at week 4, and 1 of 12 (8%) at week 8 ( Table 1 ). 2 of 27 pts (7%) from group B had a significant prolongation at week 2: one of them had an increase from 498 to 509 ms, then to 512 at week 4 and 486 at week 8. Conclusions: Baseline prolonged QTc is a common finding. QTc prolongation = 500 ms is rare in pts receiving ME for cancer pain. No data exists for other opioids. There was one case of temporary increase in QTc > 500 ms. There was no evidence of severe arrhythmias or torsade de pointes clinically or on EKG. ME dose was = 50 mg/day in the majority of these pts.

[Table: see text]

No significant financial relationships to disclose.

Interval between first palliative care consultation and death in patients with advanced cancer

9028

Background: Most referrals to acute palliative care (PC) services occur late in the trajectory of the disease, although an earlier intervention can decrease patients’ (pts) symptoms distress. The purpose of this study was to determine the time interval between first palliative care consultation (PC1) and death (D) in pts diagnosed with advanced cancer (aCA) at our comprehensive cancer center and whether such interval has increased over time. Methods: The study group was 2,868 consecutive pts who had their PC1 during a 30-month period. We reviewed the charts for information about demographics, cancer type, date of cancer diagnosis, aCA diagnosis, PC1, and D. aCA was defined as locally recurrent or metastatic. Results: 1,404 pts (49%) were female, 1,791 (62%) were < 65 years old, 2,563 (89%) had solid cancer, and 2,004 (70%) were white. The median PC1-D, aCA- PC1, and aCA-D intervals were 40, 114, and 243 days respectively. The median PC1-D interval (days) was: 47 for pts with solid cancer vs 14 for pts with hematological malignancy (p < 0.0001); 44 for pts < 65 years old vs 36 for pts = 65 years old (p = 0.002); 45 for females vs 37 for males (p = 0.004); 40 for white pts vs 41 for pts from other ethnicities (p = 0.42). The median PC1-D interval in 5 consecutive half-years was 46, 56, 42, 41, and 34 days respectively (p = 0.02). The total number of pts referred for PC1 in this period increased 20%, from 544 to 654. The ratio of PC involvement period in the aCA-D interval (PC1-D/aCA-D) decreased from 0.30 to 0.26 over the 5 half-year periods (p = 0.0004) ( Table ). Conclusions: Patients with solid cancers, younger pts, and females pts were referred earlier to acute PC. Referral timing was not affected by ethnicity. The interval between first palliative care consult and death has decreased over time. Education is needed among referring physicians to increase this interval. Further research on increasing acute PC access and its impact on PC1-D interval is needed.

[Table: see text]

No significant financial relationships to disclose.

Donepezil for cancer-related fatigue: A double-blind, randomized, placebo-controlled study

9003

Background: Fatigue is the most frequent symptom in advanced cancer. No standard treatment is available. We previously found that open-label donepezil significantly improved fatigue by day 3 and 7 in patients (pts) on opioids for cancer pain (Fisch et al, ASCO 2003). The purpose of this study was to compare donepezil (D) with placebo (P) for fatigue in pts with advanced cancer. Methods: In this randomized, double-blind, placebo-controlled trial, pts with fatigue score = 4 on a 0 to 10 scale (10 = worst fatigue) for > 1 week, hemoglobin = 10g/dl for = 4 weeks, and no major contraindication to D were randomized to receive D 5 mg or P orally every morning for 7 days. All pts were offered open-label D during week 2. Assessment included: research nurse daily phone call for fatigue and toxicity evaluation, Edmonton Symptom Assessment System (ESAS), Functional Assessment for Chronic Illness Therapy-Fatigue (FACIT-F), Sleeping Pattern Assessment, and overall effectiveness of the treatment. The FACIT-F fatigue subscale score on day 8 was considered the primary endpoint. Results: 103 pts were evaluable for final analysis. Mean difference in scores for symptoms intensity between baseline and day 8 are shown in Table 1 . FACIT-F fatigue subscale score at day 8 decreased a mean of 6 (10.6 SD) in the D arm (p < 0.001) and 7.2 (9.5 SD) in the P arm (p < 0.001). There was no significant difference in fatigue improvement between both arms according to the FACIT-F subscale (p = 0.57) and ESAS fatigue (p = 0.18) scores, and no significant difference in sleep quality score between D and P. On day 15 of the open-label phase, mean fatigue intensity remained significantly improved as compared to baseline on FACIT-F fatigue subscale (p < 0.001) and ESAS fatigue (p < 0.001) scores. No significant toxicities were observed. Conclusions: Both donepezil and placebo resulted in significant fatigue improvement. Donepezil was not significantly superior to placebo after one week. Our pilot findings are probably due to placebo effect.

No significant financial relationships to disclose.

[Table: see text]

Spirituality, quality of life, and locus of control in a palliative care setting

18529

Background: A patient’s spirituality/religious beliefs have a profound role on how one copes with disease & on quality of life (QOL). Perceptions of control play an important role in coping not only with stressful experiences, but also in health outcomes. Therefore, the primary objective was to determine whether patients’ spirituality/ religiosity correlates with quality of life and locus of control. Methods: As part of a pilot study, pts presenting for initial outpatient evaluation in the Department of Symptom Control & Palliative Care were enrolled and completed self-report measures: Functional Assessment of Chronic Illness Therapy-General (FACT-G), FACT-Spiritual Well-Being Scale (FACT-Sp), Duke University Religion Index (DUREL), Locus of Control (LOC), Herth Hope Scale (HHS), Predestination (PDQ), and Hospital Anxiety & Depression Scale (HADS). LOC contained 3 subscales: perceived occurrence of chance, dependence on powerful others, and internal control. Pearson correlation coefficients were calculated to explore the relationship between measures. The Mann-Whitney t-test was used to compare patient scores. Results: One hundred patients (48 men & 52 women) completed the surveys & 90% reported a Christian affiliation. QOL was positively correlated with FACT-Sp (p ≤ 0.001, r = .614) and the DUREL which measures both external/internal religiosity (p ≤ .01, r = .291). Interestingly, there was no gender difference in spirituality as measured by FACT-Sp; however, by the DUREL women engaged more frequently in private religious activity when compared with men (p < 0.001). Men had more perceived internal control with less emphasis on the occurrence of chance events or dependence on powerful others on LOC (p = 0.07), as well as a positive correlation with controlling of one’s own fate as measured by the PDQ (p = 0.1). Conclusions: As oncologists committed to providing comprehensive care, we need to be receptive to the spiritual needs of our patients since it augments their QOL and to empower them to have a sense of control. Future studies need to further define these complex relationships and to recognize possible gender differences.

No significant financial relationships to disclose.

Switching from methadone to a different opioid: What is the equianalgesic dose ratio?

8617

Background: Methadone (ME) is a highly effective opioid agonist used for difficult pain syndromes. However, the rotation from ME to another opioid may be difficult because of the absence of a uniformly accepted conversion ratio. Methods: We retrospectively reviewed consecutive medical records of Pts undergoing an opioid rotation from ME to an alternative opioid. For inclusion, Pts were required to have received ME for at least 3 days prior to the switch and reach a stable dose of the alternative opioid(s) during 7 days following. Stable dose was defined as a 30% or less change in opioid dose from one day to the next. For purposes of analysis, on the day before the switch, doses, were divided into ME doses and the oral morphine equivalent daily dose (MEDD), based on medication and route of all other opioids taken on that day, using standard equinalgesic tables. All doses after the switch were converted to the MEDD. For Pts receiving ME and a second opioid prior to the switch, the MEDD of the second opioid was subtracted from the MEDD calculated for the day when stable dose was reached. The remainder was used to calculate the equianalgesic raio with the previous ME dose. Results: Records on 39 Pts met inclusion criteria. Excluded from analysis were 5 Pts who were restarted on ME in < 8 days, 2 whose opioid dose markedly decreased of post switch, and 3 due to concerns about reliability of multiple routes used for fentanyl. Data from 29 Pts, 10 female, mean age 48 ±14.4 were evaluable. The ratio for: oral ME to MEDD was 1:4.7 (CL 3.0–6.5)(n=16), IV ME to MEDD was 1:13.5 (CL6.6–20.5)(n=13), p=0.06. ME dose is significantly correlated to stable MEDD after switching opioids for both ME IV and oral (Spearman=0.86,p=0.0001 and Spearman=0.72, p=0.0024, respectively. Mean day of achieving stable dose was on day 2.5 ±0.2 for IV ME and day 2.6±0.3 for oral ME. Conclusions: These dose ratios are new findings that will assist in switching Pts more safely to alternative opioids, when side effects or pain problems occur.An important difference in analgesic potency appears to exist between IV and oral ME. Further research with prospective studies is required.

No significant financial relationships to disclose.

Characterization of cancer pain syndromes (PS) seen at a Comprehensive Cancer Center (CCC) and pain response (PR) to palliative care consultation (PCC)

8551

Background: Comparison of cancer PS across settings is challenging due to differences in prognostic features. Data from 1 CCC participating in a multi-site international study of a pain classification system is presented to characterize cancer PS & response to PCC. Methods: The Edmonton Classification System for Cancer Pain was completed by prospective chart review to characterize PS of 100 consecutive hospitalized patients (pts) seen in PCC. Pts were followed until major PR, hospital discharge or death. Major PR was defined as <2 p.r.n. opioid doses/d & pain intensity (PI) <3/10 for 3 consecutive days (d). Results: 85% of pts had pain (n=85), with age 62.9+13.3, 47.1% male & KPS 44.5+23.1. The most common tumor diagnoses were lung (24.7%) & GU (21.2%). Pts were followed for a median of 4 d (0–27). 39% achieved a major PR. Except for steroids (49.4%) & anticonvulsants (29.4%), other adjuvant analgesic use was all <10%. Pain-associated features: *Numeric Rating Scale 0–10, 10=worst suggestivie of alcoholism + Mean morphine equivalent dailydose On univariate analysis, older age (p=.006), lower initial PI (p=.003), lower final PI (p=.001) & lower final MEDD (p=.002) were significantly associated with achieving major PR. On multivariate analysis, lower initial PI (p=.03) & lower final MEDD (p=.02) retained significance for achieving major PR. Conclusions: Only 39%of pts with cancer pain seen in PCC achieve a major PR by discharge or death. Despite aggressive opioid titration, 61% do not achieve a major PR & require better pain management. Potential strategies for achieving improved PR include earlier PCC, identification of more sensitive prognostic variables &critical evaluation of targeted therapies.

[Table: see text]

No significant financial relationships to disclose.

[Clinical application of sural nerve island flap pedicled with collateral vessels]

OBJECTIVE

To sum up the application experience of the sural nerve island flap pedicled with the collateral vessels.

METHODS

From 1997, the retrograde-flow sural nerve island flaps pedicled with collateral vessels were performed to repair the soft tissues defects of the shank in 3 cases, ankle in 3 cases and foot in 8 cases.

RESULTS

Twelve flaps were survived, one flap was partially necrosed and one flap was necrosed. Among them, 10 wounds healed by first intention, 3 cases were healed after changing dressing and the one necrosed flap was repaired by free flap transplantation. Nine cases were followed up for 3 to 21 months and had fine appearance and function. The flap texture was similar to normal skin, the sensation of flap partially recovered after 6 months.

CONCLUSION

The flap has more reliable blood supply and great rotation arc, it is easy to resect with little injury. It is excellent for repairing the soft tissues defect in the anterior leg, ankle and proximal half of foot. It is more significant while the main blood vessels are damaged.

[An epidemiological investigation of eperythrozoon infection in human and animals (II)]

This paper reported an epidemiological investigation on human and animals infection of eperythrozoon in 1 provinces. The results showed that eperythrozoon infection appeared in human as well as in swines, sheep, cats, donkeis and chickens. Due to geographical variations, the infection rates showed a significant difference, both in human and animals. The infection rate was not associated with sex, age or occupation in human, but was associated with seasons in animals. High peak of infection rates in animals was in May, June, July and August.