Publications by authors named "Chia-Hsien Chen"

28 Publications

  • Page 1 of 1

Effectiveness of shared decision-making intervention in patients with lumbar degenerative diseases: A randomized controlled trial.

Patient Educ Couns 2021 Mar 10. Epub 2021 Mar 10.

Cochrane Taiwan, Taipei Medical University, Taipei, Taiwan; Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan.

Objective: To evaluate the efficacy of shared decision-making (SDM) intervention among patients with lumbar degenerative diseases (LDDs) in terms of decision self-efficacy, control preferences, SDM process, decision satisfaction, and conflict.

Methods: A total of 130 outpatients with LDDs recruited from orthopedic or rehabilitation clinics were randomly assigned to the SDM intervention (n = 67) or comparison (n = 63) groups. Patients in the intervention group received decision aids (DAs) with decision coaching and those in controlled group received standard educational materials from a health educator. The primary outcome was decision self-efficacy, and secondary outcomes were control preference, SDM process, conflict, and satisfaction.

Results: The SDM intervention significantly improved decision self-efficacy (mean difference [MD] = 7.1, 95% confidence interval [CI]: 1.7-12.5, partial η = 0.05) and reduced conflict (MD = -7.0, 95% CI: -12.2 to -1.9, partial η = 0.06), especially in patients without family involvement, compared with the health education group. However, no significant between-group differences were observed in other outcomes.

Conclusion: SDM intervention improved SDM self-efficacy and reduced conflict in patients with LDDs.

Practice Implications: Clinicians can integrate DAs and decision coaching in SDM conversations. SDM intervention seems to engage patients in decision-making, especially those without family involvement.
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http://dx.doi.org/10.1016/j.pec.2021.03.002DOI Listing
March 2021

Influenza vaccination reduces incidence of peripheral arterial occlusive disease in elderly patients with chronic kidney disease.

Sci Rep 2021 Mar 1;11(1):4847. Epub 2021 Mar 1.

Department of Primary Care Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.

An influenza vaccination might reduce the risk of incident peripheral arterial occlusive disease (PAOD) in patients with chronic kidney disease (CKD), but supporting evidence is limited. This case-crossover study analyzed data from Taiwan's real-world National Health Insurance Research Database. This study included elderly (≥ 67 years old) patients with CKD having incident PAOD from January 1, 2006, to June 30, 2015. We defined 1 year before PAOD onset as the index date for the self-control group. A conditional logistic regression model was used to investigate exposure to an influenza vaccination for estimating the risk for incident PAOD following vaccination. In total, this study included 46,782 elderly patients with CKD having incident PAOD. The odds ratios for incident PAOD were 0.85 (95% confidence interval 0.77-0.94), 0.85 (0.79-0.92), 0.84 (0.79-0.90), and 0.85 (0.81-0.90) at 1, 2, 3, and 4 months after an influenza vaccination, respectively. We observed consistent results for the subgroups of patients with CKD and concomitant diabetes. However, we did not observe any beneficial effects of influenza vaccination in patients with advanced CKD or end-stage renal disease. This study demonstrated that influenza vaccination may be associated with a reduced risk of incident PAOD among patients with early-stage CKD.
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http://dx.doi.org/10.1038/s41598-021-84285-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921588PMC
March 2021

Molybdenum Tungsten Disulfide with a Large Number of Sulfur Vacancies and Electronic Unoccupied States on Silicon Micropillars for Solar Hydrogen Evolution.

ACS Appl Mater Interfaces 2020 Dec 26;12(49):54671-54682. Epub 2020 Nov 26.

Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.

Hydrogen energy is a promising alternative for fossil fuels because of its high energy density and carbon-free emission. Si is an ideal light absorber used in solar water splitting to produce H gas because of its small band gap, appropriate conduction band position, and high theoretical photocurrent. However, the overpotential required to drive the photoelectrochemical (PEC) hydrogen evolution reaction (HER) on bare Si electrodes is severely high owing to its sluggish kinetics. Herein, a molybdenum tungsten disulfide (MoS-WS) composite decorated on a Si photoabsorber is used as a cocatalyst to accelerate HER kinetics and enhance PEC performance. This MoS-WS hybrid showed superior catalytic activity compared with pristine MoS or WS. The optimal MoS-WS/Si electrode delivered a photocurrent of -25.9 mA/cm at 0 V (vs reversible hydrogen electrode). X-ray absorption spectroscopy demonstrated that MoS-WS possessed a high hole concentration of unoccupied electronic states in the MoS component, which could promote to accept large amounts of carriers from the Si photoabsorber. Moreover, a large number of sulfur vacancies are generated in the MoS constituent of this hybrid cocatalyst. These sulfur defects served as HER active sites to boost the catalytic efficiency. Besides, the TiO-protective MoS-WS/Si photocathode maintained a current density of -15.0 mA/cm after 16 h of the photocatalytic stability measurement.
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http://dx.doi.org/10.1021/acsami.0c15905DOI Listing
December 2020

Boosting Solar Hydrogen Production of Molybdenum Tungsten Sulfide-Modified Si Micropyramids by Introducing Phosphate.

ACS Appl Mater Interfaces 2020 Sep 31;12(37):41515-41526. Epub 2020 Aug 31.

Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.

Si is regarded as a promising photocathode material for solar hydrogen evolution reaction (HER) because of its small band gap and highly negative conduction band edge. However, bare Si electrodes have high overpotential because of sluggish HER kinetics on the surface. In this study, molybdenum tungsten sulfide (MoS-WS) was decorated on Si photocathodes as the co-catalyst to accelerate HER kinetics. The catalytic performance of MoS-WS was further enhanced by introducing phosphate materials. Phosphate-modified molybdenum tungsten sulfide (PO-MoWS) was deposited on Si photoabsorbers to provide an optimal current of -15.0 mA cm at 0 V. Joint characterizations of X-ray photoelectron and X-ray absorption spectroscopies demonstrated that the phosphate material dominantly coordinated with the WS component in PO-MoWS. Moreover, this phosphate material induced a large number of sulfur vacancies in the PO-MoWS/Si electrodes that contributed to the ideal catalytic activity. Herein, TiO thin films were prepared as the protective layer to improve the stability of photocathodes. The PO-MoWS/2 nm TiO/Si electrode maintained 83.8% of the initial photocurrent after chronoamperometric measurement was performed for 8000 s.
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http://dx.doi.org/10.1021/acsami.0c11538DOI Listing
September 2020

Concentrated stress effects of contoured and non-contoured high Tibial osteotomy plates: A finite-element study.

Clin Biomech (Bristol, Avon) 2020 08 11;78:105089. Epub 2020 Jun 11.

Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. Electronic address:

Background: The TomoFix plate has been extensively used in high tibial osteotomy surgery to stabilize the distracted tibial bones. However, distal pain related to plate irritation was considered one of the most relevant complications for this fixation device. This study aimed to correlate reports of distal pain with the profiles of the distracted tibia and initial plate and plate contour.

Methods: This study used the finite-element method to investigate the profile-, distraction-, and contour-induced effects on stress distribution of the distal tibia-plate contact. The associations of two tibia profiles (normal and concave), distraction angles, and two plate profiles (contoured and non-contoured) were discussed in this study. The areas and stresses of the distal tibia-plate contact were chosen as comparison indices.

Findings: Before weight-bearing, the non-contoured plates of the normal and concave tibia profiles consistently showed less contact area at the distal tibia-plate region. Consequently, the physiological loads make the non-contoured plate subject to more concentrated bone stresses and thus may induce more pain at the distal tibia-plate region than a contoured plate. When the distraction angle decreases, the tibia-plate gap increases. Prior to fixation, the tibia-plate gap can be evaluated by the profiles of the distracted tibia and non-contoured plate by use of anteroposterior radiograph and computer-aided simulation.

Interpretation: In the situations of a lower distraction angle or a large tibia-plate gap, the use of a plate bender or a lag screw is recommended in order to contour the plate for reducing the concentrated stress at the distal tibia-plate region.
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http://dx.doi.org/10.1016/j.clinbiomech.2020.105089DOI Listing
August 2020

Biomechanical analysis of single-level interbody fusion with different internal fixation rod materials: a finite element analysis.

BMC Musculoskelet Disord 2020 Feb 14;21(1):100. Epub 2020 Feb 14.

Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan.

Background: Lumbar spinal fusion with rigid spinal fixators as one of the high risk factors related to adjacent-segment failure. The purpose of this study is to investigate how the material properties of spinal fixation rods influence the biomechanical behavior at the instrumented and adjacent levels through the use of the finite element method.

Methods: Five finite element models were constructed in our study to simulate the human spine pre- and post-surgery. For the four post-surgical models, the spines were implanted with rods made of three different materials: (i) titanium rod, (ii) PEEK rod with interbody PEEK cage, (iii) Biodegradable rod with interbody PEEK cage, and (iv) PEEK cage without pedicle screw fixation (no rods).

Results: Fusion of the lumbar spine using PEEK or biodegradable rods allowed a similar ROM at both the fusion and adjacent levels under all conditions. The models with PEEK and biodegradable rods also showed a similar increase in contact forces at adjacent facet joints, but both were less than the model with a titanium rod.

Conclusions: Flexible rods or cages with non-instrumented fusion can mitigate the increased contact forces on adjacent facet joints typically found following spinal fixation, and could also reduce the level of stress shielding at the bone graft.
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http://dx.doi.org/10.1186/s12891-020-3111-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023693PMC
February 2020

Incomplete insertion of pedicle screws in a standard construct reduces the fatigue life: A biomechanical analysis.

PLoS One 2019 1;14(11):e0224699. Epub 2019 Nov 1.

Department of Orthopedic Surgery, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.

Pedicle screws are commonly used for posterior stabilization of the spine. When used in deformed or degenerated segments, the pedicle screws are often not fully inserted into the bone, but instead the threaded portion is exposed by 1 or 2 threads to accommodate rod placement and ensure alignment between the tulip of the screw and the rod. However, broken pedicle screws have been reported with the use of this method. The aim of this study was to determine how the fatigue life of the screw is affected by not fully inserting the screw into the bone. Spinal constructs were evaluated in accordance with ASTM F1717. The following three screw positions were subjected to compression bending fatigue loading; (i) pedicle screw fully inserted in the test block with no threads exposed (EXP-T0), (ii) pedicle screw inserted with one thread exposed outside the test block (EXP-T1), (iii) pedicle screw inserted with two threads exposed outside the test block (EXP-T2). Corresponding finite element models FEM-T0, FEM-T1 and FEM-T2 were also constructed and subjected to the same axial loading as the experimental groups to analyze the stress distribution in the pedicle screws and rods. The results showed that under a 190 N axial load, the EXP-T0 group survived the full 5 million cycles, the EXP-T1 group failed at 3.7 million cycles on average and the EXP-T2 groups failed at 1.0 million cycles on average, while the fatigue strength of both the EXP-T1 and EXP-T2 groups was 170 N. The constructs failed through fracture of the pedicle screw. In comparison to the FEM-T0 model, the maximum von Mises stress on the pedicle screw in the FEM-T1 and FEM-T2 models increased by 39% and 58%, respectively. In conclusion, this study demonstrated a drastic decrease in the fatigue life of pedicle screws when they are not full inserted into the plastic block.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224699PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6824572PMC
March 2020

Radiofrequency neurotomy in chronic lumbar and sacroiliac joint pain: A meta-analysis.

Medicine (Baltimore) 2019 Jun;98(26):e16230

Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City.

Background: Effective treatment of low back pain (LBP) originating in the lumbar and sacroiliac joints is difficult to achieve. The objective of the current study was to compare the clinical effectiveness of radiofrequency (RF) neurotomy versus conservative nonsurgical approaches for the management of chronic lumbar and sacroiliac joint pain.

Methods: The PICOS framework was adhered to (P [population]: patients with a history of chronic function-limiting lumbar and sacroiliac joint pain lasting at least 6 months; I [intervention]: RF neurotomy; C [comparator]: other nonsurgical treatments; O [outcomes]: the Oswestry Disability Index (ODI), measurement for pain, and a quality of life (QoL) questionnaire; S [study design]: meta-analysis). Two trained investigators systematically searched Medline, Cochrane, EMBASE, and ISI Web of Knowledge databases for relevant studies published in English through March 2019.

Results: Patients treated with RF neurotomy (n = 528) had significantly greater improvement in ODI scores, pain scores and QoL measured by EQ-5D compared with controls (n = 457); however, significant heterogeneity was observed when data were pooled from eligible studies. In subgroup analyses, patients who received RF neurotomy had a significantly greater improvement in ODI scores compared with those with sham treatment. Patients treated with RF achieved significantly greater improvement in pain scores compared with controls who received sham treatment or medical treatment. In a subgroup analysis of pain in the sacroiliac joint and in lumbar facet joints, the RF neurotomy group achieved a significantly greater improvement in ODI score and pain scores compared with the control group. The ODI score and pain score were improved after 2 months of follow up in the analyses stratified by follow-up duration.

Conclusions: Use of RF neurotomy as an intervention for chronic lumbar and sacroiliac joint pain led to improved function; however, larger, more directly comparable studies are needed to confirm this study's findings.
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http://dx.doi.org/10.1097/MD.0000000000016230DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6617467PMC
June 2019

The stability of long-segment and short-segment fixation for treating severe burst fractures at the thoracolumbar junction in osteoporotic bone: A finite element analysis.

PLoS One 2019 4;14(2):e0211676. Epub 2019 Feb 4.

Department of Orthopedic Surgery, Taipei Municipal Wanfang Hospital, Taipei Medical University, Taipei, Taiwan.

The majority of compressive vertebral fractures in osteoporotic bone occur at the level of the thoracolumbar junction. Immediate decompression is often required in order to reduce the extent of neurological damage. This study evaluated four fixation methods for decompression in patients with thoracolumbar burst fractures, and presented the most suitable method for osteoporotic patients. A finite element model of a T7-L5 spinal segment was created and subjected to an L1 corpectomy to simulate a serious burst fracture. Five models were tested: a) intact spine; 2) two segment fixation (TSF), 3) up-three segment fixation (UTSF), below-three segment fixation (BTSF), and four segment fixation (FSF). The ROM, stiffness and compression ratio of the fractured vertebra were recorded under various loading conditions. The results of this study showed that the ROM of the FSF model was the lowest, and the ROMs of UTSF and BTSF models were similar but still greater than the TSF model. Decreasing the BMD to simulate osteoporotic bone resulted in a ROM for the four instrumented models that was higher than the normal bone model. Of all models, the FSF model had the highest stiffness at T12-L2 in extension and lateral bending. Similarly, the compression ratio of the FSF model at L1 was also higher than the other instrumented models. In conclusion, FSF fixation is suggested for patients with osteoporotic thoracolumbar burst fractures. For patients with normal bone quality, both UTSF and BTSF fixation provide an acceptable stiffness in extension and lateral bending, as well as a favorable compression ratio at L1.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0211676PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6361511PMC
November 2019

Estimation of Blood Pressure in the Radial Artery Using Strain-Based Pulse Wave and Photoplethysmography Sensors.

Micromachines (Basel) 2018 Oct 29;9(11). Epub 2018 Oct 29.

Department of Pediatrics, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan.

Blood pressure (BP) is a crucial indicator of cardiac health and vascular status. This study explores the relationship between radial artery BP and wrist skin strain. A BP estimation method based on the physical model of wrist skin tissues and pulse wave velocity (PWV) is proposed. A photoplethysmography (PPG) sensor and strain gauge are used in this method. The developed strain-based pulse wave sensor consists of a pressing force sensor, which ensures consistent pressing force, and a strain gauge, which measures the cardiac pulsation on the wrist skin. These features enable long-term BP monitoring without incurring the limb compression caused by a cuff. Thus, this method is useful for individuals requiring continuous BP monitoring. In this study, the BP of each participant was measured in three modes (before, during, and after exercise), and the data were compared using a clinically validated sphygmomanometer. The percentage errors of diastolic and systolic BP readings were, respectively, 4.74% and 4.49% before exercise, 6.38% and 6.10% during exercise, and 5.98% and 4.81% after a rest. The errors were compared with a clinically validated sphygmomanometer.
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http://dx.doi.org/10.3390/mi9110556DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266472PMC
October 2018

Sintered dicalcium pyrophosphate treatment attenuates estrogen deficiency-associated disc degeneration in ovariectomized rats.

Drug Des Devel Ther 2018 18;12:3033-3041. Epub 2018 Sep 18.

Department of Orthopedic Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan,

Background: Estrogen deficiency is associated with musculoskeletal disorders. Sintered dicalcium pyrophosphate (SDCP) is a novel antiosteoporotic agent. In this study, we examined its use for restoration of bone quality and attenuation of disc degeneration in ovariectomy rats.

Methods: Sixty female Sprague Dawley rats were randomly divided into 3 groups, namely sham group undergoing sham surgery, ovariectomy (OVX) group receiving an equivalent volume of isotonic sodium chloride solution, and OVX/SDCP group orally administered with 0.25 mg/mL SDCP. Animals were sacrificed at 3 and 6 months post ovariectomy and lumbar vertebrae and intervertebral discs were harvested. Bone mineral density, micro-computed tomography analysis, and biomechanical testing were performed to assess bone quality. Histological analysis with hematoxylin and eosin, Alcian blue, and Masson's trichrome stain were conducted to determine disc degeneration. Immunohistochemistry and real-time PCR were carried out to measure the expressions of aggrecan, type I collagen, type II collagen, and MMP-1, MMP-3, and MMP-13.

Results: SDCP improved bone quality as observed by the results of increased bone mineral density and stiffness in OVX rats. The improvement in disc degeneration induced by estrogen withdrawal was associated with reduced gene expressions of MMPs and increased production of collagen type II.

Conclusion: SDCP prevents osteoporosis and ameliorates disc degeneration in OVX rats. It represents a favorable therapeutic agent for osteoporotic and osteoarthritic conditions in clinical practice.
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http://dx.doi.org/10.2147/DDDT.S170816DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6151093PMC
December 2018

Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain.

Reg Anesth Pain Med 2018 May;43(4):425-433

Background And Objectives: This study is a meta-analysis of randomized controlled trials comparing the efficacy of transcutaneous electrical nerve stimulation (TENS) to a control and to other nerve stimulation therapies (NSTs) for the treatment of chronic back pain.

Methods: Citations were identified in MEDLINE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov through June 2014 using the following keywords: nerve stimulation therapy, transcutaneous electrical nerve stimulation, back pain, chronic pain. Control treatments included sham, placebo, or medication only. Other NSTs included electroacupuncture, percutaneous electrical nerve stimulation, and percutaneous neuromodulation therapy.

Results: Twelve randomized controlled trials including 700 patients were included in the analysis. The efficacy of TENS was similar to that of control treatment for providing pain relief (standardized difference in means [SDM] = -0.20; 95% confidence interval [CI], -0.58 to 0.18; P = 0.293). Other types of NSTs were more effective than TENS in providing pain relief (SDM = 0.86; 95% CI, 0.15-1.57; P = 0.017). Transcutaneous electrical nerve stimulation was more effective than control treatment in improving functional disability only in patients with follow-up of less than 6 weeks (SDM = -1.24; 95% CI, -1.83 to -0.65; P < 0.001). There was no difference in functional disability outcomes between TENS and other NSTs.

Conclusions: These results suggest that TENS does not improve symptoms of lower back pain, but may offer short-term improvement of functional disability.
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http://dx.doi.org/10.1097/AAP.0000000000000740DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5916478PMC
May 2018

Assessment of the suitability of biodegradable rods for use in posterior lumbar fusion: An in-vitro biomechanical evaluation and finite element analysis.

PLoS One 2017 16;12(11):e0188034. Epub 2017 Nov 16.

Department of Orthopedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.

Interbody fusion with posterior instrumentation is a common method for treating lumbar degenerative disc diseases. However, the high rigidity of the fusion construct may produce abnormal stresses at the adjacent segment and lead to adjacent segment degeneration (ASD). As such, biodegradable implants are becoming more popular for use in orthopaedic surgery. These implants offer sufficient stability for fusion but at a reduced stiffness. Tailored to degrade over a specific timeframe, biodegradable implants could potentially mitigate the drawbacks of conventional stiff constructs and reduce the loading on adjacent segments. Six finite element models were developed in this study to simulate a spine with and without fixators. The spinal fixators used both titanium rods and biodegradable rods. The models were subjected to axial loading and pure moments. The range of motion (ROM), disc stresses, and contact forces of facet joints at adjacent segments were recorded. A 3-point bending test was performed on the biodegradable rods and a dynamic bending test was performed on the spinal fixators according to ASTM F1717-11a. The finite element simulation showed that lumbar spinal fusion using biodegradable implants had a similar ROM at the fusion level as at adjacent levels. As the rods degraded over time, this produced a decrease in the contact force at adjacent facet joints, less stress in the adjacent disc and greater loading on the anterior bone graft region. The mechanical tests showed the initial average fatigue strength of the biodegradable rods was 145 N, but this decreased to 115N and 55N after 6 months and 12 months of soaking in solution. Also, both the spinal fixator with biodegradable rods and with titanium rods was strong enough to withstand 5,000,000 dynamic compression cycles under a 145 N axial load. The results of this study demonstrated that biodegradable rods may present more favourable clinical outcomes for lumbar fusion. These polymer rods could not only provide sufficient initial stability, but the loss in rigidity of the fixation construct over time gradually transfers loading to adjacent segments.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188034PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5690668PMC
December 2017

Percutaneous pedicle screw placement under single dimensional fluoroscopy with a designed pedicle finder-a technical note and case series.

Spine J 2017 09 20;17(9):1373-1380. Epub 2017 Jun 20.

Department of Orthopedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan No. 291, Zhongzheng Rd, Zhonghe District, New Taipei City, 23561, Taiwan; Department of Orthopedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan No. 250, Wu-Xing Street, Taipei City, 110, Taiwan. Electronic address:

Background Context: Minimally invasive spine surgery has become increasingly popular in clinical practice, and it offers patients the potential benefits of reduced blood loss, wound pain, and infection risk, and it also diminishes the loss of working time and length of hospital stay. However, surgeons require more intraoperative fluoroscopy and ionizing radiation exposure during minimally invasive spine surgery for localization, especially for guidance in instrumentation placement. In addition, computer navigation is not accessible in some facility-limited institutions.

Purpose: This study aimed to demonstrate a method for percutaneous screws placement using only the anterior-posterior (AP) trajectory of intraoperative fluoroscopy.

Study Design: A technical report (a retrospective and prospective case series) was carried out.

Patient Sample: Patients who received posterior fixation with percutaneous pedicle screws for thoracolumbar degenerative disease or trauma comprised the patient sample.

Method: We retrospectively reviewed the charts of consecutive 670 patients who received 4,072 pedicle screws between December 2010 and August 2015. Another case series study was conducted prospectively in three additional hospitals, and 88 consecutive patients with 413 pedicle screws were enrolled from February 2014 to July 2016. The fluoroscopy shot number and radiation dose were recorded. In the prospective study, 78 patients with 371 screws received computed tomography at 3 months postoperatively to evaluate the fusion condition and screw positions.

Results: In the retrospective series, the placement of a percutaneous screw required 5.1 shots (2-14, standard deviation [SD]=2.366) of AP fluoroscopy. One screw was revised because of a medialwall breach of the pedicle. In the prospective series, 5.8 shots (2-16, SD=2.669) were required forone percutaneous pedicle screw placement. There were two screws with a Grade 1 breach (8.6%), both at the lateral wall of the pedicle, out of 23 screws placed at the thoracic spine at T9-T12. Forthe lumbar and sacral areas, there were 15 Grade 1 breaches (4.3%), 1 Grade 2 breach (0.3%), and 1 Grade 3 breach (0.3%). No revision surgery was necessary.

Conclusion: This method avoids lateral shots of fluoroscopy during screw placement and thus decreases the operation time and exposes surgeons to less radiation. At the same time, compared with the computer-navigated procedure, it is less facility-demanding, and provides satisfactory reliability and accuracy.
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http://dx.doi.org/10.1016/j.spinee.2017.06.022DOI Listing
September 2017

Optimized decellularization protocol including α-Gal epitope reduction for fabrication of an acellular porcine annulus fibrosus scaffold.

Cell Tissue Bank 2017 Sep 24;18(3):383-396. Epub 2017 Mar 24.

Institute of Biomedical Engineering, College of Engineering, College of Medicine, National Taiwan University, No. 1, Sec. 1, Jen-Ai Road, Taipei, Taiwan.

Recent advances in tissue engineering have led to potential new strategies, especially decellularization protocols from natural tissues, for the repair, replacement, and regeneration of intervertebral discs. This study aimed to validate our previously reported method for the decellularization of annulus fibrosus (AF) tissue and to quantify potentially antigenic α-Gal epitopes in the decellularized tissue. Porcine AF tissue was decellularized using different freeze-thaw temperatures, chemical detergents, and incubation times in order to determine the optimal method for cell removal. The integrity of the decellularized material was determined using biochemical and mechanical tests. The α-Gal epitope was quantified before and after decellularization. Decellularization with freeze-thaw in liquid nitrogen, an ionic detergent (0.1% SDS), and a 24 h incubation period yielded the greatest retention of GAG and collagen relative to DNA reduction when tested as single variables. Combined, these optimal decellularization conditions preserved more GAG while removing the same amount of DNA as the conditions used in our previous study. Components and biomechanical properties of the AF matrix were retained. The decellularized AF scaffold exhibited suitable immune-compatibility, as evidenced by successful in vivo remodeling and a decrease in the α-Gal epitope. Our study defined the optimal conditions for decellularization of porcine AF tissues while preserving the biological composition and mechanical properties of the scaffold. Under these conditions, immunocompatibility was evidenced by successful in vivo remodeling and reduction of the α-Gal epitope in the decellularized material. Decellularized AF scaffolds are potential candidates for clinical applications in spinal surgery.
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http://dx.doi.org/10.1007/s10561-017-9619-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5587617PMC
September 2017

Removal of fixation construct could mitigate adjacent segment stress after lumbosacral fusion: A finite element analysis.

Clin Biomech (Bristol, Avon) 2017 Mar 23;43:115-120. Epub 2017 Feb 23.

Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, Taiwan; Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taiwan. Electronic address:

Background Data: Combined usage of posterior lumbar interbody fusion and transpedicular fixation has been extensively used to treat the various lumbar degenerative disc diseases. The transpedicular fixator aims to increase stability and enhance the fusion rate. However, how the fused disc and bridged vertebrae respectively affect adjacent-segment diseases progression is not yet clear.

Methods: Using a validated lumbosacral finite-element model, three variations at the L4-L5 segment were analyzed: 1) moderate disc degeneration, 2) instrumented with a stand-alone cage and pedicle screw fixators, and 3) with the cage only after fusion. The intersegmental angles, disc stresses, and facet loads were examined. Four motion tests, flexion, extension, bending, and twisting, were also simulated.

Findings: The adjacent-segment disease was more severe at the cephalic segment than the caudal segment. After solid fusion and fixation, the increase in intersegmental angles, disc stresses and facet loads of the adjacent segments were about 57.6%, 47.3%, and 59.6%, respectively. However, these changes were reduced to 30.1%, 22.7%, and 27.0% after removal of the fixators. This was attributed to the differences between the biomechanical characteristics of the fusion and fixation mechanisms.

Interpretation: Fixation superimposes a stiffer constraint on the mobility of the bridged segment than fusion. The current study suggested that the removal of spinal fixators after complete fusion could decrease the stress at adjacent segments. Through a minimally invasive procedure, we could reduce secondary damage to the paraspinal structures while removing the fixators, which is of utmost concern to surgeons.
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http://dx.doi.org/10.1016/j.clinbiomech.2017.02.011DOI Listing
March 2017

The effects of tibia profile, distraction angle, and knee load on wedge instability and hinge fracture: A finite element study.

Med Eng Phys 2017 04 5;42:48-54. Epub 2017 Feb 5.

Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei, Taiwan. Electronic address:

Several plate systems for high tibial osteotomy (HTO) have been developed to stabilize the opening wedge of an osteotomized tibia. Among them, the TomoFix system, having a quasi-straight and T-shaped design, has been widely adopted in the literature. However, this system is implemented by inserting a lag (i.e., cortical) screw through the proximal combi-hole, to deform the plate and pull the distal tibia toward the plate. This process potentially induces plate springback and creates an elastic preload on the osteotomized tibia, especially at the lateral hinge of the distracted wedge. Using the finite-element method, this study aims to investigate the contoured effect of lag-screw application on the biomechanical behavior of the tibia-plate construct. Two tibial profiles (normal and more concave), three distraction angles (6°, 9°, and 12°), and three knee loads (intraoperative: contouring plate; postoperative: weight and nonweight bearing) are systematically varied in this study. The wedge instability and fracture risk at the lateral hinge are chosen as the comparison indices. The results show the necessity of preoperative planning for a precontoured procedure, rather than elastic deformation using a lag screw. Within the intraoperative period, a more concave tibial profile and/or reduced distraction angle (i.e., 6° or 9°) necessitate a higher compressive load to elastically deform the plate, thereby deteriorating the lateral-hinge fracture risk. A precontoured plate is recommended in the case that the proximal tibia is highly concave and the distraction angle is insufficient to stretch the tibial profile.
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http://dx.doi.org/10.1016/j.medengphy.2017.01.007DOI Listing
April 2017

Biomechanical arrangement of threaded and unthreaded portions providing holding power of transpedicular screw fixation.

Clin Biomech (Bristol, Avon) 2016 11 23;39:71-76. Epub 2016 Sep 23.

Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, Taiwan; Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taiwan. Electronic address:

Background: Failure of pedicle screw is a major concern in spinal surgery. The threaded and unthreaded portions of the pedicle screw provide the ability to anchor and squeeze the surrounding bone, respectively. This study aimed to investigate the anchoring and squeezing effects of different design of the threaded/unthreaded portions of a pedicle screw to vertebrae.

Methods: Four variations (one fully and three partially threaded, with a 1/3, 1/2, and 2/3 unthreaded designs at the proximal portion) of screws were used to measure pullout strength and withdrawn energy using synthetic and porcine specimens. The tests were conducted in static and dynamic fashions, in that the screws were axially extracted directly and after 150,000cycles of lateral bending. The load-displacement curves were recorded to gain insight into the peak load (pullout strength) and cumulative work (withdrawn energy).

Findings: The two testing results of the synthetic and porcine specimens consistently showed that the 1/3 unthreaded screw provides significantly higher pullout strength and withdrawn energy than the fully threaded screw. The withdrawn energy of the three unthreaded screws was significantly higher than that of the threaded counterpart.

Interpretation: The holding power of a pedicle screw was the integration of the anchoring (cancellous core) and squeezing (compact pedicle) effects within the threaded and unthreaded portions. The current study recommends the 1/3 unthreaded screw as an optimal alternative for use as a shank-sliding mechanism to preserve the holding power within the pedicle isthmus.
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http://dx.doi.org/10.1016/j.clinbiomech.2016.09.010DOI Listing
November 2016

In vitro Penetration and in vivo Distribution of Honokiol into the Intervertebral Disc in Rat.

Anal Sci 2015 ;31(12):1297-302

Institute of Traditional Medicine, National Yang Ming University.

Honokiol is a potential candidate for the treatment of intervertebral disc (IVD) degeneration. In this study, we develop in vitro and in vivo methods to detect the distribution of honokiol in intervertebral discs using high-performance liquid chromatography. A rat tail disc was used for both experimental models. For the in vivo animal experiment, blood samples and tail discs were collected at 15, 30, 60, 120 and 240 min after honokiol administration (30 mg/kg, i.v.). The analyte was separated by a mobile phase of methanol and 10 mM NaH2PO4 buffer at pH 2.8 (78:22, v/v) and pumped through a reversed-phase analytical column (250 × 4.6 mm, particle size 5 μm) at room temperature. The in vitro experimental results demonstrated that honokiol diffused into the intervertebral disc and was concentration-dependent. The active concentration is obtained for the therapeutic level at 15 and 30 min after honokiol administration in the in vivo model.
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http://dx.doi.org/10.2116/analsci.31.1297DOI Listing
October 2016

The effect of annular repair on the failure strength of the porcine lumbar disc after needle puncture and punch injury.

Eur Spine J 2016 Mar 9;25(3):906-12. Epub 2015 Nov 9.

Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, No.291, Zhongzheng Rd., Zhonghe District, New Taipei City, 23561, Taiwan.

Purpose: The purpose was to quantify the structural integrity of annulus fibrosis (AF) after injuries with repair.

Methods: Punctures in the AF of 6-month-old porcine spine specimens were made with 18-, 20-, 22-, 24-, and 26-gauge needles. Leakage testing was performed immediately after needle puncture (Group 1), after the puncture was repaired with a modified purse-string suture (MPSS) (Group 2), and after needle puncture with immediate repair (Group 3). Punch injuries repaired with the MPSS alone, or with an AF graft and MPSS were also examined.

Results: There was no leakage from 26-gauge needle punctures. Pressures at which the nucleus pulposus leaked from the 24-, 22-, 20- and 18-gauge needle punctures (Group 1) were 4.28, 2.03, 1.27, and 1.06 MPa, respectively. Failure pressure after repair (Group 2, 3) was significantly greater than without (Group 1). Failure pressure in Group 3 was much greater than in Group 2 with 18- and 20-gauge punctures. Punch injury repaired with a graft and MPSS had significantly greater failure pressure than repair with MPSS alone (1.88 vs. 1.02 MPa, p = 0.0001).

Conclusions: The MPSS can restore the mechanical integrity of the AF after needle puncture. An annular graft along with a MPSS may increase the structural integrity of the AF after a punch injury. As this was an acute animal study, the measurements and results may not directly translate to the human intervertebral disc.
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http://dx.doi.org/10.1007/s00586-015-4316-0DOI Listing
March 2016

Extracorporeal shockwave therapy improves short-term functional outcomes of shoulder adhesive capsulitis.

J Shoulder Elbow Surg 2014 Dec;23(12):1843-1851

Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan. Electronic address:

Background: The treatment of adhesive capsulitis is a dilemma for orthopaedic rehabilitation specialists. In this study, we assessed whether extracorporeal shockwave therapy (ESWT) improves the functional outcome of primary shoulder adhesive capsulitis.

Methods: In this prospective, randomized, controlled, single-blind clinical trial, we enrolled 40 patients with primary adhesive capsulitis to assess whether ESWT can improve the functional outcome of primary adhesive capsulitis better than oral steroid therapy. Patients were allocated to the oral steroid group or ESWT group with randomization. Functional outcome evaluations were performed using the Constant Shoulder Score (CSS) and Oxford Shoulder Score.

Results: Both groups showed significant improvement in the Oxford Shoulder Score evaluation throughout the study period. In the ESWT group, the total CSS and range of motion (ROM) parameter of the CSS in the ESWT group showed significant improvement from the fourth week that was better than that in the steroid group; the activities–of–daily living (ADL) parameter of the CSS achieved significance and was better than that in the steroid group at the sixth week. For the steroid group, pain was significantly reduced from baseline to the fourth week of the study; ADL and ROM improved at the fourth to 12th week. For the ESWT group, ADL and ROM improvements were significant from baseline to the sixth week.

Conclusion: Our results showed that ESWT can be an alternative treatment, at least in the short-term, for primary adhesive capsulitis of the shoulder. In addition, all of the side effects of ESWT were transient and tolerable.
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http://dx.doi.org/10.1016/j.jse.2014.08.010DOI Listing
December 2014

Better Osteoporotic Fracture Healing with Sintered Dicalcium Pyrophosphate (SDCP) Treatment: A Rat Femoral Fracture Model.

J Histochem Cytochem 2014 Aug 14;62(8):565-76. Epub 2014 May 14.

Institute of Clinical Medicine (YJK, JSS) National Yang Ming University, Taipei, TaiwanInstitute of Microbiology and Immunology (CHC) National Yang Ming University, Taipei, TaiwanInstitute of Traditional Medicine (THT, YHT) National Yang Ming University, Taipei, TaiwanDepartment of Orthopaedics (YJK), School of Medicine, College of MedicineGraduate Institute of Clinical Medicine (JSS, GR), School of Medicine, College of MedicineDepartment of Orthopaedics, Shang-Ho Hospital (GR, CHC, YHT) Taipei Medical University, Taipei, TaiwanDepartment of Orthopaedic Surgery, National Taiwan University Hospital Hsin Chu Branch, Hsin-Chu, Taiwan (JSS)Department of Orthopaedics, Shang-Ho Hospital (CHC, GR, YHT)Department of Orthopaedics, School of Medicine, National Taiwan University Hospital Hsin Chu Branch, Hsin-Chu, Taiwan (JSS).

The aim of this study was to evaluate the effect of sintered dicalcium pyrophosphate (SDCP) on fracture healing in an osteoporotic rat model. Female Sprague-Dawley rats (8 weeks old) were randomly allocated into five groups: sham-operated group, and bilateral ovariectomized group treated with SDCP, alendronate, calcitonin, or no treatment. Rats were sacrificed at 6 or 16 weeks after fracture. Fracture sites were examined by microcomputed tomography (microCT), histology, and mechanical testing. The results showed that SDCP mildly suppressed callus remodeling at 6 weeks, but not at 16 weeks. The lamellar bone in the callus area and new cortical shell formation in SDCP-treated group were similar to that of the sham group at 16 weeks after fracture, indicating there was no delayed callus remodeling into lamellar bone. At both 6 and 16 weeks after fracture, ultimate stress and elastic modulus were similar between the SDCP and sham groups, and the mechanical strength in these groups was better than that in other groups. Finally, analysis of the serum bone markers CTX-1 and P1NP suggested that SDCP decreased the bone turnover rate and promoted proper fracture healing. The effect of SDCP is superior to that of alendronate and calcitonin in the healing of osteoporotic fractures.
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http://dx.doi.org/10.1369/0022155414538264DOI Listing
August 2014

Complete Femoral Nerve Palsy Following Traumatic Iliacus Hematoma: A Case Report and Literature Review.

JBJS Case Connect 2013 Jul;3(3 Suppl 1):e741-4

Department of Radiology (J.-W.K.), Department of Orthopaedics (C.-J.C., G.R., C.-Y.C., C.-H.C.), Shuang-Ho Hospital, Taipei Medical University, Taipei, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 23561, Taiwan. E-mail address for C.-H. Chen:

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July 2013

Complete Femoral Nerve Palsy Following Traumatic Iliacus Hematoma: A Case Report and Literature Review.

JBJS Case Connect 2013 Jul-Sep;3(3):e74

Department of Radiology (J.-W.K.), Department of Orthopaedics (C.-J.C., G.R., C.-Y.C., C.-H.C.), Shuang-Ho Hospital, Taipei Medical University, Taipei, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 23561, Taiwan. E-mail address for C.-H. Chen:

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http://dx.doi.org/10.2106/JBJS.CC.L.00291DOI Listing
December 2017

Calcitonin inhibits SDCP-induced osteoclast apoptosis and increases its efficacy in a rat model of osteoporosis.

PLoS One 2012 6;7(7):e40272. Epub 2012 Jul 6.

Department of Orthopaedic, Taipei Medical University Hospital, Taipei, Taiwan, Republic of China.

Introduction: Treatment for osteoporosis commonly includes the use of bisphosphonates. Serious side effects of these drugs are caused by the inhibition of bone resorption as a result of osteoclast apoptosis. Treatment using calcitonin along with bisphosphonates overcomes these side-effects in some patients. Calcitonin is known to inhibit bone resorption without reducing the number of osteoclasts and is thought to prolong osteoclast survival through the inhibition of apoptosis. Further understanding of how calcitonin inhibits apoptosis could prove useful to the development of alternative treatment regimens for osteoporosis. This study aimed to analyze the mechanism by which calcitonin influences osteoclast apoptosis induced by a bisphosphate analog, sintered dicalcium pyrophosphate (SDCP), and to determine the effects of co-treatment with calcitonin and SDCP on apoptotic signaling in osteoclasts.

Methods: Isolated osteoclasts were treated with CT, SDCP or both for 48 h. Osteoclast apoptosis assays, pit formation assays, and tartrate-resistant acid phosphatase (TRAP) staining were performed. Using an osteoporosis rat model, ovariectomized (OVX) rats received calcitonin, SDCP, or calcitonin + SDCP. The microarchitecture of the fifth lumbar trabecular bone was investigated, and histomorphometric and biochemical analyses were performed.

Results: Calcitonin inhibited SDCP-induced apoptosis in primary osteoclast cultures, increased Bcl-2 and Erk activity, and decreased Mcl-1 activity. Calcitonin prevented decreased osteoclast survival but not resorption induced by SDCP. Histomorphometric analysis of the tibia revealed increased bone formation, and microcomputed tomography of the fifth lumbar vertebrate showed an additive effect of calcitonin and SDCP on bone volume. Finally, analysis of the serum bone markers CTX-I and P1NP suggests that the increased bone volume induced by co-treatment with calcitonin and SDCP may be due to decreased bone resorption and increased bone formation.

Conclusions: Calcitonin reduces SDCP-induced osteoclast apoptosis and increases its efficacy in an in vivo model of osteoporosis.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040272PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3391248PMC
April 2013

Novel diterpenes from the heartwood of Chamaecyparis obtusa var. formosana.

Chem Pharm Bull (Tokyo) 2004 Jun;52(6):764-6

Department of Chemistry, National Taiwan University, Taipei, Taiwan 106, ROC.

Two novel diterpenes, obtusanal B (1) and obtusadione (2), along with obtusanal A (3), obtunone (4), 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial, 8,12-dihydroxydielmentha-5,9-diene-7,11-dione and myrcene, isolated from the heartwood of Chamaecyparis obtusa var. formosana, were characterized by spectroscopic means, including 2D-NMR techniques. Compounds 1 and 2 are 7(6-->2)abeoabietane and 14(8-->9)abeoabietane type diterpenes, respectively. Their biosyntheses were proposed.
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http://dx.doi.org/10.1248/cpb.52.764DOI Listing
June 2004

New lignans from the heartwood of Chamaecyparis obtusa var. formosana.

Chem Pharm Bull (Tokyo) 2002 Jul;50(7):978-80

Department of Chemistry, National Taiwan University, Tapei, Taiwan, ROC.

Four new lignans, 3',4'-O,O-demethylenehinokinin (1), chamalignolide (2), 8'beta-hydroxyhinokinin (3) and 7beta,8beta-epoxyzuonin A (4), as well as (-)-hinokinin (5), and (-)-zuonin A (6), were isolated from the heartwood of Chamaecyparis obtusa var. formosana. The structures of these lignans were unambiguously determined by spectroscopic methods. And the absolute configuration of 1 was elucidated with a circular dichroism (CD) spectrum.
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http://dx.doi.org/10.1248/cpb.50.978DOI Listing
July 2002

Five new cadinane-type sesquiterpenes from the heartwood of Chamaecyparis obtusa var. formosana.

J Nat Prod 2002 Jan;65(1):25-8

Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China.

Muurola-4,10(14)-dien-3-one (1), 10-O-acetyl-15-oxo-alpha-cadinol (2), 15-hydroxy-alpha-cadinol (3), 4alpha-hydroxy-5beta-ethoxy-epi-cubenol (4), and 4alpha-hydroxy-5beta-acetoxy-epi-cubenol (5), five new bicyclic sesquiterpenes, have been isolated from the heartwood of Chamaecyparis obtusa var. formosana along with the known compounds epi-cubenol, T-cadinol, T-muurolol, delta-cadinol, and alpha-cadinol. The structures of the new constituents were elucidated through chemical and spectral studies.
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http://dx.doi.org/10.1021/np0101402DOI Listing
January 2002