Publications by authors named "Dapeng Fan"

17 Publications

  • Page 1 of 1

Pre-Pressure Optimization for Ultrasonic Motors Based on Multi-Sensor Fusion.

Sensors (Basel) 2020 Apr 8;20(7). Epub 2020 Apr 8.

National University of Defense Technology, Deya Road No. 109, Kaifu District, Changsha 410073, China.

This paper investigates the pre-pressure's influence on the key performance of a traveling wave ultrasonic motor (TRUM) using simulations and experimental tests. An analytical model accompanied with power dissipation is built, and an electric cylinder is first adopted in regulating the pre-pressure rapidly, flexibly and accurately. Both results provide several new features for exploring the function of pre-pressure. It turns out that the proportion of driving zone within the contact region declines as the pre-pressure increases, while a lower power dissipation and slower temperature rise can be achieved when the driving zones and the braking zones are in balance. Moreover, the shrinking speed fluctuations with the increasing pre-pressures are verified by the periodic-varying axial pressure. Finally, stalling torque, maximum efficiency, temperature rise and speed variance are all integrated to form a novel optimization criterion, which achieves a slower temperature rise and lower stationary error between 260 and 320 N. The practical speed control errors demonstrate that the proportion of residual error declines from 2.88% to 0.75% when the pre-pressure is changed from 150 to 300 N, which serves as one of the pieces of evidence of the criterion's effectiveness.
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http://dx.doi.org/10.3390/s20072096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7181230PMC
April 2020

Open arthrolysis for elbow stiffness increases carrying angle but has no impact on functional recovery.

BMC Musculoskelet Disord 2016 09 9;17(1):388. Epub 2016 Sep 9.

Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, People's Republic of China, 200233.

Background: With the exception of normal anatomic changes in the medial collateral ligament and radial head, other factors related to carrying angle changes have not been systematically studied. We reviewed patients who underwent open arthrolysis of the elbow, and evaluated if open arthrolysis could change carrying angle. We then identified factors associated with carrying angle changes.

Methods: Fifty patients with a minimum of 24 months of follow-up after open arthrolysis were evaluated retrospectively. Preoperative and postoperative carrying angles were compared.

Results: The carrying angles of 36 elbows in 36 patients were unchanged after surgery (Group A), while the carrying angles of 14 elbows in 14 patients increased postoperatively (Group B). In Group A, mean postoperative extension and flexion were 7° (range 0-24°) and 125° (range 10-135°) respectively, while mean postoperative pronation and supination were 60° (range 50-80°) and 65° (range 30-85°), respectively. In Group B, mean postoperative extension and flexion were 25° (range 0-40°) and 128° (range 60-138°), while mean postoperative pronation and supination were 65° (range 45-85°) and 60° (range 45-75°), respectively. No significant difference in range of motion and Mayo Elbow Performance Score was observed between the two groups.

Conclusions: During open arthrolysis, humeral trochlea debridement and techniques for improving forearm rotation could increase carrying angle. However, this had no impact on elbow functional recovery.
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http://dx.doi.org/10.1186/s12891-016-1205-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017133PMC
September 2016

Laser scanning by rotating polarization gratings.

Appl Opt 2016 Jul;55(19):5149-57

Laser beam scanning can be realized using two independently rotating, inline polarization gratings, termed Risley gratings, in a fashion similar to Risley prisms. The analytical formulas of pointing position as well as their inverse solutions are described. On this basis, the beam scanning is investigated and the performance of scanning imaging is evaluated. It is shown that the scanning function in 1D scanning evolves from a sinusoidal to triangular scan and the duty cycle increases rapidly as the ratio of grating period to wavelength is reduced toward 2. The scan pattern in 2D scanning is determined by the ratio k of the gratings' rotatory frequency. In imaging applications, when k tends toward 1 or -1, the scan pattern becomes dense and is inclined to be spiral or rose-like, respectively, which is desirable for the purpose of enhancing spatial resolution. There is a direct trade-off between spatial resolution and frame rate. The spiral and rose scanning enable multiresolution imaging, providing a preview of the scanned area in a fraction of the overall scan time, which is extremely useful for fast, real-time imaging applications.
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http://dx.doi.org/10.1364/AO.55.005149DOI Listing
July 2016

[ROLE OF Smad4 ON FIBROSIS OF TENDON DERIVED FIBROBLASTS INDUCED BY TRANSFORMING GROWTH FACTOR β BY TARGETED REGULATION OF miRNA219-5P].

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2016 May;30(5):641-646

Department of Orthopaedics, the Sixth Affiliated People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200233, P. R. China.

Objective: To investigate the effect of Smad4 on the fibrosis of tendon derived fibroblasts (TDFs) induced by transforming growth factor β(TGF-β) by targeted regulation of miRNA219-5P (miR219-5P).

Methods: The tendons donated by the volunteers were harvested to isolate and culture TDFs. The 3rd generation cells were used for experiment. Chemically synthesized miR219-5P mimics, miR219-5P inhibitor, and negative control sequences were transfected into TDFs. The gene expression of miR219-5P in TDFs was detected by real-time PCR, and the protein expression of Smad4 in TDFs was detected by Western blot at 48 hours after transfection. The combining sites of miR219-5P and Smad4 in 3'UTR district were predicted by informatics software. Wild type and mutant type reporter gene expression vectors were constructed and then targeted verification was carried out by the luciferase reporter gene test. Transfected TDFs were then induced by TGF-β. The proliferation activity of the cells were measured by the cell counting kit 8 after culturing for 24, 48, and 72 hours. The expressions of fibrosis related proteins in TDFs were detected by Western blot at 72 hours.

Results: After TDFs were transfected by miR219-5P mimics, miR219-5P expression was significantly up-regulated, but the expressions of Smad4 was decreased subsequently (<0.05). Intracellular expression of miR219-5P was inhibited by miR219-5P mimics inhibitor, however, the protein expression of Smad4 was significantly increased (<0.05). Luciferase reporter gene test showed that luciferase activities were significantly decreased in pGL3-WT-Smad4+mimics group, but were significantly increased in pGL3-WT-Smad4+inhibitor group when compared with pGL3-WT-Smad4 transfected group (<0.05), but no significant difference was found between GL3-MT-Smad4+mimics and pGL3-MT-Smad4+inhibitor groups (>0.05). Cell proliferation and the fibrosis related proteins were increased in TGF-β induced TDFs, however, decreased in TGF-β induced TDFs after transfected by miR219-5P inhibitor (<0.01).

Conclusions: miR219-5P can significantly inhibit fibrosis of TDFs induced by TGF-β by down-regulating Smad4 expression.
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http://dx.doi.org/10.7507/1002-1892.20160128DOI Listing
May 2016

The use of SHP-2 gene transduced bone marrow mesenchymal stem cells to promote osteogenic differentiation and bone defect repair in rat.

J Biomed Mater Res A 2016 08 30;104(8):1871-81. Epub 2016 Mar 30.

Department of Orthopaedics, Shanghai Jiaotong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai, 200233, People's Republic of China.

Bone tissue engineering is a promising approach for bone regeneration, in which growth factors play an important role. The tyrosine phosphatase Src-homology region 2-containing protein tyrosine phosphatase 2 (SHP2), encoded by the PTPN11 gene, is essential for the differentiation, proliferation and metabolism of osteoblasts. However, SHP-2 has never been systematically studied for its effect in osteogenesis. We predicted that overexpression of SHP-2 could promote bone marrow-derived mesenchymal stem cell (BMSC)osteogenic differentiation and SHP-2 transduced BMSCs could enhance new bone formation, determined using the following study groups: (1) BMSCs transduced with SHP-2 and induced with osteoblast-inducing liquid (BMSCs/SHP-2/OL); (2) BMSCs transduced with SHP-2 (BMSCs/-SHP-2); (3) BMSCs induced with osteoblast-inducing liquid (BMSCs/OL) and (4) pure BMSCs. Cells were assessed for osteogenic differentiation by quantitative real-time polymerase chain reaction analysis, western blot analysis, alkaline phosphatase activity and alizarin red S staining. For in vivo assessment, cells were combined with beta-tricalcium phosphate scaffolds and transplanted into rat calvarial defects for 8 weeks. Following euthanasia, skull samples were explanted for osteogenic evaluation, including micro-computed tomography measurement, histology and immunohistochemistry staining. SHP-2 and upregulation of its gene promoted BMSC osteogenic differentiation and therefore represents a potential new therapeutic approach to bone repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1871-1881, 2016.
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http://dx.doi.org/10.1002/jbm.a.35718DOI Listing
August 2016

Release of celecoxib from a bi-layer biomimetic tendon sheath to prevent tissue adhesion.

Mater Sci Eng C Mater Biol Appl 2016 Apr 17;61:220-6. Epub 2015 Dec 17.

Department of Orthopaedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai 200233, PR China. Electronic address:

Posttraumatic tendon adhesion limits the motion of the limbs greatly. Biomimetic tendon sheaths have been developed to promote tendon healing and gliding. However, after introduction of these biomaterials, the associated inflammatory responses can decrease the anti-adhesion effect. Celecoxib is a non-steroidal anti-inflammatory drug (NSAID) that can decrease inflammation responses. We blended hyaluronic acid and poly(l-lactic acid)-polyethylene glycol (PELA) with microgel electrospinning technology to form an inner layer of a bi-layer biomimetic sheath using sequential electrospinning of an outer celecoxib-PELA layer. Electrospun bi-layer fibrous membranes were mechanically tested and characterized by morphology, surface wettability, and drug release. The tensile strength showed a decreased trend and water contact angles were 114.7 ± 3.9°, 103.6 ± 4.4°, 116.3 ± 5.1°, 122.8 ± 4.7°, and 126.5 ± 4.2° for the surface of PELA, hyaluronic acid-PELA, 2, 6, and 10% celecoxib-PELA electrospun fibrous membranes, respectively. In vitro drug release studies confirmed burst release and then sustained release from the fibrous membranes containing celecoxib for 20 days. In a chicken model of flexor digitorum profundus tendon surgery, the outer celecoxib/PELA layer offered advanced anti-adhesion roles compared to the outer PELA layer and the inner hyaluronic acid-loaded PELA layer still offered tendon healing and gliding. Thus, celecoxib-loaded anti-adhesive tendon sheaths can continuously offer bi-layer biomimetic tendon sheath effects with celecoxib release from the outer layer to prevent tendon adhesion.
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http://dx.doi.org/10.1016/j.msec.2015.12.028DOI Listing
April 2016

Multi-layer electrospun membrane mimicking tendon sheath for prevention of tendon adhesions.

Int J Mol Sci 2015 Mar 26;16(4):6932-44. Epub 2015 Mar 26.

Department of Orthopaedics, Shanghai Jiaotong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China.

Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid)-polyethylene glycol (PELA) electrospun fibrous membrane as the outer layer, hyaluronic acid (HA) gel as middle layer, and PELA electrospun fibrous membrane as the inner layer was designed. The anti-adhesion efficacy of this multi-layer membrane was compared with a single-layer use in rabbit flexor digitorum profundus tendon model. The surface morphology showed that both PELA fibers and celecoxib-loaded PELA fibers in multi-layer membrane were uniform in size, randomly arrayed, very porous, and smooth without beads. Multi-layer membrane group had fewer peritendinous adhesions and better gliding than the PELA membrane group and control group in gross and histological observation. The similar mechanical characteristic and collagen expression of tendon repair site in the three groups indicated that the multi-layer membrane did not impair tendon healing. Taken together, our results demonstrated that such a biomimetic multi-layer sheath could be used as a potential strategy in clinics for promoting tendon gliding and preventing adhesion without poor tendon healing.
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http://dx.doi.org/10.3390/ijms16046932DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4424997PMC
March 2015

Pointing error analysis of Risley-prism-based beam steering system.

Appl Opt 2014 Sep;53(25):5775-83

Based on the vector form Snell's law, ray tracing is performed to quantify the pointing errors of Risley-prism-based beam steering systems, induced by component errors, prism orientation errors, and assembly errors. Case examples are given to elucidate the pointing error distributions in the field of regard and evaluate the allowances of the error sources for a given pointing accuracy. It is found that the assembly errors of the second prism will result in more remarkable pointing errors in contrast with the first one. The pointing errors induced by prism tilt depend on the tilt direction. The allowances of bearing tilt and prism tilt are almost identical if the same pointing accuracy is planned. All conclusions can provide a theoretical foundation for practical works.
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http://dx.doi.org/10.1364/AO.53.005775DOI Listing
September 2014

Frame frequency prediction for Risley-prism-based imaging laser radar.

Appl Opt 2014 Jun;53(16):3556-64

A dual-wedge scanner has potential applications in laser imaging radar. To realize fast scanning imaging without a blind region, the rotation rates of the wedges have to be controlled to perform beam scanning along appropriate track paths. The first-order paraxial approximation method is employed to investigate the 2D scan patterns and path density for different angular frequency ratios of the wedges rotating steadily in the same and opposite directions. The frame rate of no-blind-region scanning imaging is estimated in terms of the imaging coverage requirement. The internal relations between the rotation rates, the instantaneous field of view (IFOV), and the imaging velocity are revealed. The results show that the spiral scanning trace, resulting from co-rotating wedges, is dense in the center and sparse at the edge of the scanning field. The reverse results can be obtained for the rosette scanning trace, resulting from counter-rotating wedges. The denser the scanning trace is, the longer the scan period is. The faster the wedges rotate and the wider the IFOV is, the higher the frame rate is. When the ratio of the width of IFOV to the angular radius of the scanning field is 0.15, the frame rate of no-blind-region spiral scanning imaging can be up to 18 fps for wedge rotation rate of 12000  r/min, and that for rosette scanning imaging can be up to 20 fps.
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http://dx.doi.org/10.1364/AO.53.003556DOI Listing
June 2014

Motion control of the wedge prisms in Risley-prism-based beam steering system for precise target tracking.

Appl Opt 2013 Apr;52(12):2849-57

Department of Electronic and Communication Engineering, Changsha University, Changsha, China.

Two exact inverse solutions of Risley prisms have been given by previous authors, based on which we calculate the gradients of the scan field that open a way to investigate the nonlinear relationship between the slewing rate of the beam and the required angular velocities of the two wedge prisms in the Risley-prism-based beam steering system for target tracking. The limited regions and singularity point at the center and the edge of the field of regard are discussed. It is found that the maximum required rotational velocities of the two prisms for target tracking are nearly the same and are dependent on the altitude angle. The central limited region is almost independent of the prism parameters. The control singularity at the crossing center path can be avoided by switching the two solutions.
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http://dx.doi.org/10.1364/AO.52.002849DOI Listing
April 2013

Theoretical and experimental determination of steering mechanism for Risley prism systems.

Appl Opt 2013 Mar;52(7):1389-98

College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan, China.

Two different analytical methods, the first-order paraxial approximation method and the nonparaxial ray tracing method, are applied to determine the steering mechanism of the Risley prism system, including the pointing prediction and the complete and exact inverse orientation solutions. The analytical results obtained with the two different methods are investigated in detail about the pointing prediction and the two groups of inverse orientation solutions, respectively. Risley prism equipment for wide angular range beam scanning is assembled and the experimental setup is built to test the steering mechanism of the Risley prism system. Experimental results validate the availability of the nonparaxial ray tracing method to discuss the beam steering mechanism for the Risley prism system.
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http://dx.doi.org/10.1364/AO.52.001389DOI Listing
March 2013

Association of CTLA4 gene polymorphisms with susceptibility and pathology correlation to pulmonary tuberculosis in Southern Han Chinese.

Int J Biol Sci 2012 10;8(7):945-52. Epub 2012 Jul 10.

Institute of Cell Biology, Zhejiang University, Hangzhou 310058, PR China.

The cytotoxic T lymphocyte antigen-4 (CTLA4) gene is a key negative regulator of the T lymphocyte immune response. It has been found that CTLA4 +49A>G (rs231775), +6230G>A (rs3087243), and 11430G>A (rs11571319) polymorphisms are associated with susceptibility to many autoimmune diseases, and can down-regulate the inhibition of cellular immune response of CTLA4. Three SNPs in CTLA4 were genotyped by using the PCR and DNA sequencing methods in order to reveal the susceptibility and pathology correlation to pulmonary tuberculosis in Southern Han Chinese. We found that the frequency of CTLA4 +49AG genotype in the pulmonary tuberculosis patients (38.42%) was significantly lower than that of the healthy controls (49.77%), (P(cor)=0.038, OR 0.653, 95% CI 0.436-0.978). But, no associations were found between the other 2 SNPs (+6230G>A, 11430G>A) and tuberculosis (P>0.05). Haplotype analysis showed that the frequency of haplotype AGG in the healthy controls group (6.9%) was significantly higher than the pulmonary tuberculosis patients group (1.4%), (global P=0.005, P(cor)=0.0002, OR 0.183, 95% CI 0.072-0.468). In addition, haplotype GGA was found to be significantly related to tuberculosis with double lung lesion rather than single lung lesion (P(cor)=0.042). This study is the first to report that genetic variants in the CTLA4 gene can be associated with pulmonary tuberculosis in Southern Han Chinese, and CTLA4 +49AG genotype as well as haplotype AGG may reduce the risk of being infected with pulmonary tuberculosis. The GGA haplotype was related to tuberculosis with double lung lesion, which provides a new experimental basis to clarify the pathogenesis of pulmonary tuberculosis.
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http://dx.doi.org/10.7150/ijbs.4390DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399317PMC
November 2012

A novel single nucleotide polymorphism within the NOD2 gene is associated with pulmonary tuberculosis in the Chinese Han, Uygur and Kazak populations.

BMC Infect Dis 2012 Apr 14;12:91. Epub 2012 Apr 14.

Institute of Cell Biology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.

Background: The present study aimed to investigate the genetic polymorphisms in exon 4 of the NOD2 gene in tuberculosis patients and healthy controls, in order to clarify whether polymorphisms in the NOD2 gene is associated with tuberculosis.

Methods: A case-control study was performed on the Chinese Han, Uygur and Kazak populations. Exon 4 of the NOD2 gene was sequenced in 425 TB patients and 380 healthy controls to identify SNPs.

Results: The frequency of T/G genotypes for the Arg587Arg (CGT → CGG) single nucleotide polymorphism (SNP) in NOD2 was found to be significantly higher in the Uygur (34.9%) and Kazak (37.1%) populations than the Han population (18.6%). Also, the frequency of G/G genotypes for the Arg587Arg SNP was significantly higher in the Uyghur (8.3%) and Kazak (5.4%) populations than the Han population (0.9%). Meanwhile, no significant difference was found in the Arg587Arg polymorphism between the tuberculosis patients and healthy controls in the Uyghur and Kazak populations (P > 0.05) whereas, a significant difference was observed in the Arg587Arg polymorphism between the tuberculosis patients and healthy controls in the Han population (P < 0.01). The odd ratio of 2.16 (95% CI = 1.31-3.58; P < 0.01) indicated that the Arg587Arg SNP in NOD2 may be associated with susceptibility to tuberculosis in the Chinese Han population.

Conclusions: Our study is the first to demonstrate that the Arg587Arg SNP in NOD2 is a new possible risk factor for tuberculosis in the Chinese Han population, but not in the Uyghur and Kazak populations. Our results may reflect racial differences in genetic susceptibility to tuberculosis.
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http://dx.doi.org/10.1186/1471-2334-12-91DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3379957PMC
April 2012

Polymorphic allele of human MRC1 confer protection against tuberculosis in a Chinese population.

Int J Biol Sci 2012 23;8(3):375-82. Epub 2012 Feb 23.

Institute of Cell Biology, Zhejiang University, Hangzhou, PR China.

Mannose receptor is a member of the C-type lectin receptor family involved in pathogen molecular-pattern recognition, and plays a critical role in shaping host immune response. Single nucleotide polymorphisms (SNPs) in the MRC1 gene may affect expression levels and differences in the structure and function of proteins in different individuals, thereby affecting individual susceptibility to pulmonary tuberculosis. However, to date, MRC1 polymorphisms associated with susceptibility to pulmonary tuberculosis have not yet been reported. The present study aimed to investigate potential associations of SNPs in the MRC1 gene with pulmonary tuberculosis in a Chinese population. Six SNPs (G1186A, G1195A, T1212C, C1221G, C1303T and C1323T) in exon 7 of the MRC1 gene were genotyped using the PCR and DNA sequencing methods in the pulmonary tuberculosis patients and the healthy controls. Linkage disequilibrium analysis was performed between polymorphic sites. The study found that the allele frequency of G1186A (rs34039386) of the MRC1 gene in a Chinese population was higher in the pulmonary tuberculosis group than the healthy control group. There was a significant difference in frequency distribution between the two groups (P = 0.037; OR = 0.76; 95% CI, 0.58-0.98). Genotypic analysis also indicated that the AG genotypes in a Chinese population were significantly correlated with pulmonary tuberculosis (P < 0.01; OR = 0.57; 95% CI, 0.37-0.87). After adjustment for age and gender, G1186A sites were found to be dominant (P < 0.01; OR = 0.59; 95% CI, 0.40-0.87), over-dominant (P = 0.045; OR = 0.69; 95% CI, 0.47-0.99) and additive models (P = 0.041; OR = 0.76; 95% CI, 0.59-0.99) in association with pulmonary tuberculosis. But, no association was found between the other 5 SNPs (G1195A, T1212C, C1221G, C1303T and C1323T) and tuberculosis (P > 0.05). This study is the first to report that genetic variants in the MRC1 gene can be associated with pulmonary tuberculosis in a Chinese population, and may reduce the risk of infecting pulmonary tuberculosis. This also provides a new experimental basis to clarify the pathogenesis of pulmonary tuberculosis.
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http://dx.doi.org/10.7150/ijbs.4047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291854PMC
July 2012

Resection of a large atrial hemangioma using a bloodless surgical technique: a case report.

Heart Surg Forum 2007 ;10(1):E87-9

Department of Surgery, Pennsylvania Hospital, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA.

We present a biatrial hemangioma in a Jehovah's Witness patient. Hemangioma is extremely rare, accounting for 1% to 2% of benign cardiac tumors. Complete resection of a large hemangioma is mandatory due to its potentially life-threatening risk. In Jehovah's Witness patients, it is necessary to employ bloodless surgery protocols to maximize the patient's outcome. Our patient had undergone 6 weeks of monitoring and erythropoietin therapy prior to surgery, raising her hemoglobin level from 11.6 g/dL to 16.8 g/dL. Intraoperative bloodless surgical protocols as well as a continuous blood circuit were utilized. The patient's hemoglobin level on postoperative day one was 14.5 g/dL; one year postsurgery, the patient was symptom free.
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http://dx.doi.org/10.1532/HSF98.20061078DOI Listing
March 2007

Intraoperative neurophysiologic detection of iatrogenic C5 nerve root injury during laminectomy for cervical compression myelopathy.

Spine (Phila Pa 1976) 2002 Nov;27(22):2499-502

Surgical Monitoring Associates, Inc., Bala Cynwyd, Pennsylvania 19004, USA.

Study Design: A retrospective and prospective study was conducted to investigate intraoperative neurophysiologic monitoring during cervical laminectomy to detect iatrogenic C5 nerve root palsy.

Objective: To evaluate the usefulness of various intraoperative neuromonitoring methods for identifying C5 nerve root palsy.

Summary Of Background Data: One unsolved complication after laminectomy or laminoplasty for cervical compression myelopathy is C5 nerve root palsy. It can go undetected even in the presence of intraoperative neuromonitoring with conventional upper extremity mixed nerve or dermatomal somatosensory-evoked potentials or transcranial motor-evoked potentials, recording typically from hand muscles.

Methods: The intraoperative neuromonitoring data of 200 patients who underwent cervical laminectomy for myelopathy between 1998 and 2000 were reviewed for C5 nerve root palsy. Retrospective studies were conducted for the first 132 patients, who were monitored with conventional techniques including ulnar and posterior tibial nerve somatosensory-evoked potentials, C5-C7 dermatomally evoked potentials, and transcranial electrical motor-evoked potentials recorded from hand and leg muscles. Prospective studies then were applied to the remaining 68 patients, for whom transcranial electrical motor-evoked potentials and spontaneous electromyography were monitored from deltoid and biceps muscles in the wake of undetected C5 nerve root palsy from conventional neurophysiologic monitoring methods.

Results: In the retrospective cohort, six patients presented after surgery with C5 nerve root palsy showing unilateral deltoid muscle paralysis despite entirely unremarkable conventional somatosensory-evoked potentials, dermatomally evoked potentials, and transcranial electrical motor-evoked potentials from hand and leg muscles. For the prospective cohort, two patients experienced postoperative iatrogenic C5 motor nerve root palsy. Impending C5 nerve root injuries after laminectomy were successfully identified in both patients showing significant changes in deltoid and biceps transcranial electrical motor-evoked potentials and spontaneous electromyography, thereby averting more serious consequence. There were no false-negative and false-positive results.

Conclusions: In an effort to reduce postoperative C5 nerve root palsy, the clinician should consider intraoperative deltoid and biceps transcranial electrical motor-evoked potential and spontaneous electromyography monitoring whenever there is potential for iatrogenic C5 nerve root injury.
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http://dx.doi.org/10.1097/00007632-200211150-00014DOI Listing
November 2002