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1.  Pulsed Electromagnetic Fields in the treatment of fresh scaphoid fractures. A multicenter, prospective, double blind, placebo controlled, randomized trial 
The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences.
Initially Pulsed Electromagnetic Fields was used in the treatment of tibial pseudoarthrosis and non-union. More recently there is evidence that physical forces can also be used in the treatment of fresh fractures, showing accelerated healing by 30% and 71% reduction in nonunion within 12 weeks after initiation of therapy. Until now no double blind randomized, placebo controlled trial has been conducted to investigate the effect of this treatment on the healing of fresh fractures of the scaphoid.
This is a multi center, prospective, double blind, placebo controlled, randomized trial. Study population consists of all patients with unilateral acute scaphoid fracture. Pregnant women, patients having a life supporting implanted electronic device, patients with additional fractures of wrist, carpal or metacarpal bones and pre-existing impairment in wrist function are excluded. The scaphoid fracture is diagnosed by a combination of physical and radiographic examination (CT-scanning).
Proven scaphoid fractures are treated with cast immobilization and a small Pulsed Electromagnetic Fields bone growth stimulating device placed on the cast. Half of the devices will be disabled at random in the factory.
Study parameters are clinical consolidation, radiological consolidation evaluated by CT-scanning, functional status of the wrist, including assessment by means of the patient rated wrist evaluation (PRWE) questionnaire and quality of life using SF-36 health survey questionnaire.
Primary endpoint is number of scaphoid unions at six weeks, secondary endpoints are time interval to clinical and radiological consolidation, number of non-unions, functional status at 52 weeks and non-adherence to the treatment protocol.
Trial registration
Netherlands Trial Register (NTR): NTR2064
PMCID: PMC3107178  PMID: 21548951
2.  Synthaderm in the management of pre-tibial lacerations: a controlled clinical study. 
Archives of Emergency Medicine  1987;4(3):179-186.
A clinical study of patients with pre-tibial lacerations at King's College Hospital and Guy's Hospital, London, England, compared a non-adhesive dressing with Synthaderm. Treatment was randomly allocated. At King's College Hospital, deep and superficial lacerations were equally distributed, the median time to healing with Synthaderm was significantly (P less than 0.02) reduced; and the median rate of healing (mm/day) was significantly (P less than 0.01) better. At Guy's Hospital, larger and wider wounds were unequally distributed, with fewer in the control group; in the Synthaderm group, the median rate of healing was increased. In both centres, the clinical impression was that Synthaderm reduced nursing dressing time and a better scar resulted. Synthaderm improved the rate of healing in pre-tibial lacerations.
PMCID: PMC1285441  PMID: 3318859
3.  Pulsed electromagnetic stimulation in nonunion of tibial diaphyseal fractures 
Indian Journal of Orthopaedics  2009;43(2):156-160.
Nonunion of long bones is a difficult clinical problem and challenges the clinical acumen of surgeons. Multiple surgical or nonsurgical modalities have been used to treat nonunions. Noninvasive pulsed electromagnetic stimulation is an entity known to affect the piezoelectric phenomenon of bone forming cells. We conducted a study on 45 long-bone fractures of tibia treated by pulsed electromagnetic stimulation, which are analyzed and reported.
Materials and Methods:
A total of 45 tibial fractures with established atrophic nonunion were enrolled between 1981 and 1988. All the patients had abnormal mobility and no or minimal gap at fracture site with no evidence of callus formation across the fracture site. The patients' age ranged between 24 and 68 years; 40 were men and 5 were women. All patients having evidence of infection, implant in situ, and gap nonunions were excluded from study. Pulsed electromagnetic stimulation was given using above-knee plaster of Paris cast (0.008 Weber/m2 magnetic field was created for 12 h/day). The average duration for pulsed electromagnetic stimulation (PEMS) therapy was 8.35 weeks, with the range being 6–12 weeks. The cases were evaluated at 6 weeks and subsequently every 6-weekly interval for clinical and radiological union. The withdrawal of therapy was decided as per clinicoradiological evidence of union.
All but three patients showed evidence of union. About 35% (n = 16) cases showed union in 10 weeks, and 85%(n = 38) cases showed union in 4 months. The average duration of therapy using PEMS was 8.35±0.48 weeks, and the average duration of immobilization was 3.02 ± 0.22 months. Three cases that did not show evidence of union were poorly compliant for the apparatus of PEMS.
PEMS is a useful noninvasive modality of treatment for difficult nonunion of long bones.
PMCID: PMC2762255  PMID: 19838364
Nonunion; pulsed electromagnetic stimulation; tibial diaphyseal fractures
4.  The Effect of High Voltage, High Frequency Pulsed Electric Field on Slain Ovine Cortical Bone 
High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network causing the bone strength and toughness augmentation, it apparently did not affect the mineral phase of the cortical bone material. The results also confirmed that the indirect application of high power pulsed electric field at 500 V and 10 kHz through capacitive coupling method was safe and did not destroy the bone tissue construction.
PMCID: PMC3994715  PMID: 24761375
Cortical bone tissue; effect of electrical pulsed power; high voltage and high frequency pulsed electric field; mechanical properties of cortical bone; pulsed power
5.  Pulsed electromagnetic fields for the treatment of tibial delayed unions and nonunions. A prospective clinical study and review of the literature 
Pulsed electromagnetic fields (PEMF) stimulation for the treatment of bone nonunion or delayed union have been in use for several years, but on a limited basis. The aim of this study was to assess the overall efficacy of the method in tibial delayed unions and nonunions and identify factors that could affect the final outcome.
We prospectively reviewed 44 patients (27 men) with a mean age of 49.6 ± 18.4 years that received PEMF therapy due to tibial shaft delayed union or nonunion. In all cases, fracture gap was less than 1 cm and infection or soft tissue defects were absent.
Fracture union was confirmed in 34 cases (77.3%). No relationship was found between union rate and age (p = 0.819), fracture side (left or right) (p = 0.734), fracture type (simple or comminuted, open or closed) (p = 0.111), smoking (p = 0.245), diabetes (p = 0.68) and initial treatment method applied (plates, nail, plaster of paris) (p = 0.395). The time of treatment onset didn’t affect the incidence of fracture healing (p = 0.841). Although statistical significance was not demonstrated, longer treatment duration showed a trend of increased probability of union (p = 0.081).
PEMF stimulation is an effective non-invasive method for addressing non-infected tibial union abnormalities. Its success is not associated with specific fracture or patient related variables and it couldn’t be clearly considered a time-dependent phenomenon.
PMCID: PMC3441225  PMID: 22681718
PEMF; Tibia; Fracture; Nonunion; Delayed union
6.  Comparative study of the use of electromagnetic fields in patients with pseudoarthrosis of tibia treated by intramedullary nailing 
International Orthopaedics  2009;34(3):437-440.
We made a comparative cohort study in patients suffering from tibial pseudoarthrosis, all of whom were treated by intramedullary nailing. We divided patients into two groups: one treated by intramedullary nailing only (control group) and the other by intramedullary nailing combined with pulsed electromagnetic fields (PEMFs). The study included 57 cases of tibial pseudoarthrosis in 57 patients from February 1987 to February 2002. Pseudoarthrosis was treated surgically in all cases (Grosse-Kempf dynamic intramedullary nailing). This was combined with PEMFs in 22 cases. The average age was 38.3 years (range 14–89 years) and the average duration of follow-up was 27.2 months (range 12–48 months). Forty-nine fractures (86%) healed and eight (14%) did not. Of the group treated with PEMFs, 20 (91%) healed and two (9%) did not; from the group that did not receive PEMF (35), 29 (83%) healed compared to six (17%) that did not. The relationship between union and use of PEMFs, and between time to union and use of PEMFs was clinically relevant. PEMFs are useful when treating tibial pseudoarthrosis. Its noninvasive nature means that there are more complication-free unions.
PMCID: PMC2899307  PMID: 19462169
7.  Mechanical Compromise of Partially Lacerated Flexor Tendons 
Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the “50% rule.” Few studies provide mechanical insight into the “50% rule.”
Method of Approach
In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75mm deep transverse, mid-substance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration.
Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross-section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses.
The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the “50% rule.” Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.
PMCID: PMC3697059  PMID: 23363212
Mechanics; tendon; laceration; viscoelasticity
8.  Low-Intensity Pulsed Ultrasound and Pulsed Electromagnetic Field in the Treatment of Tibial Fractures: A Systematic Review 
Journal of Athletic Training  2007;42(4):530-535.
Objective: To compare the effects of low-intensity pulsed ultrasound (LIPUS) or pulsed electromagnetic fields (PEMF) on fracture healing through a systematic review of original, English-language clinical research reports.
Data Sources: A search of MEDLINE, Physiotherapy Evidence Database (PEDro), and ProQuest to identify clinical trials of LIPUS or PEMF with fractures in humans, written in English, published from 1966 through 2004. Key words were ultrasound, fracture, tibial, electric current, and healing.
Study Selection: After search limits were applied, 17 papers were assessed independently by 2 reviewers. Papers were excluded from consideration if they lacked (1) random allocation of treatments, (2) inclusion of skeletally mature patients of either sex with a current fracture, (3) blinding of both the patient and the assessors as to treatment group, (4) administration of either LIPUS or PEMF treatments to one of the treatment groups, or (5) assessment of time to fracture healing or proportion of fractures healed, as determined radiographically, clinically, or both.
Data Extraction: Eight trials met the inclusion criteria. Methodologic quality of all trials was assessed using the PEDro criteria. Outcome measures were tabulated.
Data Synthesis: Heterogeneity among studies precluded direct comparison of the efficacy of LIPUS to that of PEMF.
Conclusions: The studies we included in our review were of generally high methodologic quality. The evidence suggests that LIPUS may speed healing of acute tibial fractures. Comparison studies of these modalities are needed to guide treatment of fractures sustained by athletic individuals.
PMCID: PMC2140080  PMID: 18174942
nonunion; modalities; radiographic healing; clinical healing
9.  The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field 
Clinics  2011;66(7):1237-1245.
Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields.
This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old).
The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays.
The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents.
Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.
PMCID: PMC3148471  PMID: 21876981
Microwave; Caspases; Creatine kinase; Testosterone; Infertility
10.  Management of a tibial periprosthetic fracture following revision knee arthroplasty using a pulsed electromagnetic field stimulation device: a case report 
Cases Journal  2009;2:8706.
Periprosthetic fractures associated with total knee arthroplasty are rare but present a challenging problem particularly when associated with revision arthroplasty. Fractures around tibial stems are particularly difficult with no accepted technique in their management. This case describes a tibial periprosthetic fracture following a revision knee arthroplasty which was successfully managed with a Pulsed ElectroMagnetic Field bone stimulation device. We believe this to be first reported use of a bone stimulation device in this clinical environment.
PMCID: PMC2769467  PMID: 19918397
11.  Lower Extremity Energy Absorption and Biomechanics During Landing, Part I: Sagittal-Plane Energy Absorption Analyses 
Journal of Athletic Training  2013;48(6):748-756.
Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing has been associated with landing biomechanics considered high risk for anterior cruciate ligament (ACL) injury. We do not know whether groups with different INI EA magnitudes exhibit meaningful differences in ACL-related landing biomechanics and whether INI EA might be useful to identify ACL injury-risk potential.
To compare biomechanical factors associated with noncontact ACL injury among sagittal-plane INI EA groups and to determine whether an association exists between sex and sagittal-plane INI EA group assignment to evaluate the face validity of using sagittal-plane INI EA to identify ACL injury risk.
Descriptive laboratory study.
Research laboratory.
Patients or Other Participants:
A total of 82 (41 men, 41 women; age = 21.0 ± 2.4 years, height = 1.74 ± 0.10 m, mass = 70.3 ± 16.1 kg) healthy, physically active individuals volunteered.
We assessed landing biomechanics using an electromagnetic motion-capture system and force plate during a double-legged jump-landing task.
Main Outcome Measure(s):
Total INI EA was used to group participants into high, moderate, and low tertiles. Sagittal- and frontal-plane knee kinematics; peak vertical and posterior ground reaction forces (GRFs); anterior tibial shear force; and internal hip extension, knee extension, and knee varus moments were identified and compared across groups using 1-way analyses of variance. We used a χ2 analysis to compare male and female representation in the high and low groups.
The high group exhibited greater knee-extension moment and posterior GRFs than both the moderate (P < .05) and low (P < .05) groups and greater anterior tibial shear force than the low group (P < .05). No other group differences were noted. Women were not represented more than men in the high group (χ2 = 1.20, P = .27).
Greater sagittal-plane INI EA likely indicates greater ACL loading, but it does not appear to influence frontal-plane biomechanics related to ACL injury. Women were not more likely than men to demonstrate greater INI EA, suggesting that quantification of sagittal-plane INI EA alone is not sufficient to infer ACL injury-risk potential.
PMCID: PMC3867085  PMID: 23944382
anterior cruciate ligament; landing biomechanics; kinetics; kinematics
12.  Moderate-Intensity Rotating Magnetic Fields Do Not Affect Bone Quality and Bone Remodeling in Hindlimb Suspended Rats 
PLoS ONE  2014;9(7):e102956.
Abundant evidence has substantiated the positive effects of pulsed electromagnetic fields (PEMF) and static magnetic fields (SMF) on inhibiting osteopenia and promoting fracture healing. However, the osteogenic potential of rotating magnetic fields (RMF), another common electromagnetic application modality, remains poorly characterized thus far, although numerous commercial RMF treatment devices have been available on the market. Herein the impacts of RMF on osteoporotic bone microarchitecture, bone strength and bone metabolism were systematically investigated in hindlimb-unloaded (HU) rats. Thirty two 3-month-old male Sprague-Dawley rats were randomly assigned to the Control (n = 10), HU (n = 10) and HU with RMF exposure (HU+RMF, n = 12) groups. Rats in the HU+RMF group were subjected to daily 2-hour exposure to moderate-intensity RMF (ranging from 0.60 T to 0.38 T) at 7 Hz for 4 weeks. HU caused significant decreases in body mass and soleus muscle mass of rats, which were not obviously altered by RMF. Three-point bending test showed that the mechanical properties of femurs in HU rats, including maximum load, stiffness, energy absorption and elastic modulus were not markedly affected by RMF. µCT analysis demonstrated that 4-week RMF did not significantly prevent HU-induced deterioration of femoral trabecular and cortical bone microarchitecture. Serum biochemical analysis showed that RMF did not significantly change HU-induced decrease in serum bone formation markers and increase in bone resorption markers. Bone histomorphometric analysis further confirmed that RMF showed no impacts on bone remodeling in HU rats, as evidenced by unchanged mineral apposition rate, bone formation rate, osteoblast numbers and osteoclast numbers in cancellous bone. Together, our findings reveal that RMF do not significantly affect bone microstructure, bone mechanical strength and bone remodeling in HU-induced disuse osteoporotic rats. Our study indicates potentially obvious waveform-dependent effects of electromagnetic fields-stimulated osteogenesis, suggesting that RMF, at least in the present form, might not be an optimal modality for inhibiting disuse osteopenia/osteoporosis.
PMCID: PMC4105536  PMID: 25047554
13.  Electromagnetic Fields 
Establishing a means to prevent osteonecrosis after corticosteroid administration is an important theme. We asked whether pulsed electromagnetic field stimulation, a noninvasive treatment, could prevent osteonecrosis. Ninety rabbits were divided into four treatment groups: (1) exposure of 10 hours per day to electromagnetic stimulation for 1 week, followed by injection of methylprednisolone (20 mg/kg), and exposure of 10 hours per day to electromagnetism for a further 4 weeks (n = 40); (2) methylprednisolone injection only (n = 40); (3) no treatment (n = 5); and (4) exposure of 10 hours per day to electromagnetism for 5 weeks (n = 5). After 5 weeks, we harvested and histologically examined femurs bilaterally. The frequency of osteonecrosis was lower in the steroid-electromagnetism group (15/40) than in the steroid-only group (26/40). No necrotic lesions were found in the two control groups. We observed no clear effects of electromagnetism on the number, location, extent, and repair of necrotic lesions and intramedullary fat cell size in affected rabbits. Pulsed electromagnetic field stimulation reportedly augments angiogenesis factors and dilates blood vessels; these effects may lower the frequency of osteonecrosis. Exposure to pulsed electromagnetic field stimulation before corticosteroid administration could be an effective means to reduce the risk of osteonecrosis.
PMCID: PMC2311468  PMID: 18350347
14.  Effect of Axial Load on Anterior Tibial Translation when Transitioning from Non-Weight Bearing to Weight Bearing 
While the application of compressive joint loads and thigh muscle activity are associated with anterior tibial translation in vitro, less is known during early load acceptance in-vivo. We investigated the effects of increasing axial loads on anterior tibial translation and thigh muscle activity in healthy knees during transition from non-weight bearing to early weight bearing.
Participants (11 Male, 11 Female) underwent 20%, 40%, and 60% body weight acceptance trials at 20° knee flexion while electromagnetic sensors measured anterior tibial translation (mm), and surface electromyography recorded quadriceps and hamstring muscle onset times (ms) and amplitudes (% maximal voluntary isometric contraction). Repeated measures ANOVA compared values across loads. Pearson correlations examined relationships between anterior tibial translation and muscle onset times and amplitudes within each load.
As load increased, anterior tibial translation (Mean (standard deviation)) (20%=4.7(1.7)mm < 40%=7.1(1.9)mm < 60%=8.8(2.1)mm), and quadriceps (20%=23.6(14.9)% maximal voluntary isometric contraction < 40%=32.7(11.8)% maximal voluntary isometric contraction < 60%=41.1(13.5)% maximal voluntary isometric contraction) and hamstring (20%=15.5(15.7)% maximal voluntary isometric contraction < 40%=23.0(16.4)% maximal voluntary isometric contraction < 60%=27.6(19.1)% maximal voluntary isometric contraction) activation increased, while quadriceps (20% = 96.7(28.4)ms > 60% 80.2(21.8)ms) and hamstring (20% = 141.5(65.0)ms & 40% = 126.3(68.8)> 60% 107.6(28.4)ms) onset times decreased (P≤0.05). There were no relationships between anterior tibial translation and muscle activation amplitudes (R = .033–.294) or onset times (R = −.031–.374)(P>.09).
Greater axial loads near full knee extension during early weight acceptance result in greater anterior tibial translation, regardless of faster and stronger activation amplitudes. These findings support injury prevention programs aimed to reduce impact forces as they may in turn reduce anterior tibial translation and corresponding ligamentous strain during dynamic activity.
PMCID: PMC2795012  PMID: 19837495
Knee; ACL; Loading Rate
15.  Pulsed Ultrasound Differentially Stimulates Somatosensory Circuits in Humans as Indicated by EEG and fMRI 
PLoS ONE  2012;7(12):e51177.
Peripheral somatosensory circuits are known to respond to diverse stimulus modalities. The energy modalities capable of eliciting somatosensory responses traditionally belong to mechanical, thermal, electromagnetic, and photonic domains. Ultrasound (US) applied to the periphery has also been reported to evoke diverse somatosensations. These observations however have been based primarily on subjective reports and lack neurophysiological descriptions. To investigate the effects of peripherally applied US on human somatosensory brain circuit activity we recorded evoked potentials using electroencephalography and conducted functional magnetic resonance imaging of blood oxygen level-dependent (BOLD) responses to fingertip stimulation with pulsed US. We found a pulsed US waveform designed to elicit a mild vibration sensation reliably triggered evoked potentials having distinct waveform morphologies including a large double-peaked vertex potential. Fingertip stimulation with this pulsed US waveform also led to the appearance of BOLD signals in brain regions responsible for somatosensory discrimination including the primary somatosensory cortex and parietal operculum, as well as brain regions involved in hierarchical somatosensory processing, such as the insula, anterior middle cingulate cortex, and supramarginal gyrus. By changing the energy profile of the pulsed US stimulus waveform we observed pulsed US can differentially activate somatosensory circuits and alter subjective reports that are concomitant with changes in evoked potential morphology and BOLD response patterns. Based on these observations we conclude pulsed US can functionally stimulate different somatosensory fibers and receptors, which may permit new approaches to the study and diagnosis of peripheral nerve injury, dysfunction, and disease.
PMCID: PMC3514181  PMID: 23226567
16.  Bone Healing: Little Secrets 
The ability to stimulate bone repair, heal non-unions, or restore lost segments of bone is a common goal among orthopaedic surgeons, trauma surgeons, and scientists who investigate wound healing responses. The stimulation of bone repair has been reported using biophysical means such as electromagnetic fields, low-intensity pulsed ultrasound and extracorporeal shockwave therapy. Reported studies on the use of these modalities suggest beneficial effects but the quality of the evidence and high between-study heterogeneity leave the impact of these biophysical stimuli on bone repair uncertain.
New biotechnologies to enhance skeletal repair have focused on growth factors, osteoinductive molecules, and, more recently, autologous adult bone marrow stem cells. Recent randomized, placebo-controlled clinical trials using recombinant human fibroblast growth factor-2 for the treatment of tibial shaft fractures, and platelet-derived growth factor for the treatment of ankle fractures have yielded potentially interesting results. More data are needed to confirm these findings. Investigations using prostaglandin EP-2 receptor agonists to enhance tibia shaft fracture healing are also under way.
Clinicians and scientists have utilized autologous bone marrow for over a century. Unprocessed preparations have shown uneven results with regard to their ability to enhance bone repair. Recent data, however, demonstrating the use of autologous bone marrow stem cells in a concentrated manner have been very encouraging. Injection of bone marrow aspirate concentrate into non-unions and in conjunction with local bone for the enhancement of spinal fusion have shown impressive results.
Perhaps the most well-investigated biotechnology for the enhancement of bone repair is the use of the bone morphogenetic proteins. BMP-2 and BMP-7 are now available as recombinant molecules and have been evaluated in both spinal and long-bone trauma applications. RhBMP-2 has demonstrated efficacy in the enhancement of single-level lumbar intervertebral body fusions and open (compound) tibia-shaft fractures. RhBMP-7 (also known as OP-1) has been shown to be effective in the treatment of recalcitrant non-unions of long bones. Fusion of the spine, however, in patients undergoing posterolateral fusions has been somewhat less successful. At this time, use of BMPs should be limited to only those applications approved by government regulatory bodies as off-label use has been associated with serious complications, such as the use of BMP-2 in the cervical spine causing airway obstruction.
Future biotechnologies to enhance bone repair are in development. One potential area of interest may be to target the Wnt signaling pathway in osteoblasts. Recent data suggesting the efficacy of Wnt proteins in the enhancement of skeletal healing suggest that this pathway may be worthy of further investigation. Although technologies for the enhancement of skeletal repair have focused on locally applied materials that are either implanted or injected, future technologies may focus on systemic means of enhancing skeletal repair. In particular, the presence of known human phenotypes associated with mutations in the receptor-ligand interactions that trigger this pathway suggests that modification of Wnt signaling may have a beneficial clinical impact when the appropriate agonist or antagonist is formulated in the appropriate way. A recent randomized, controlled trial using parathyroid hormone (1–34) to enhance the healing of distal radius fractures shows promise and may form the foundation for future investigations to develop systemic therapies for bone repair.
PMCID: PMC3213826
17.  Development and Application of Integrated Optical Sensors for Intense E-Field Measurement 
Sensors (Basel, Switzerland)  2012;12(8):11406-11434.
The measurement of intense E-fields is a fundamental need in various research areas. Integrated optical E-field sensors (IOESs) have important advantages and are potentially suitable for intense E-field detection. This paper comprehensively reviews the development and applications of several types of IOESs over the last 30 years, including the Mach-Zehnder interferometer (MZI), coupler interferometer (CI) and common path interferometer (CPI). The features of the different types of IOESs are compared, showing that the MZI has higher sensitivity, the CI has a controllable optical bias, and the CPI has better temperature stability. More specifically, the improvement work of applying IOESs to intense E-field measurement is illustrated. Finally, typical uses of IOESs in the measurement of intense E-fields are demonstrated, including application areas such as E-fields with different frequency ranges in high-voltage engineering, simulated nuclear electromagnetic pulse in high-power electromagnetic pulses, and ion-accelerating field in high-energy physics.
PMCID: PMC3472891  PMID: 23112663
electric field; E-field sensor; Pockels effect; integrated optics
18.  High-energy extracorporeal shockwave therapy in a patellar tendon animal model: a vascularization-focused study 
Clinics  2011;66(9):1611-1614.
The aim of this study was to analyze the effect of high-energy extracorporeal shockwave therapy on tendon angiogenesis in the patellar tendons of rabbits. We sought to investigate whether different voltage and number pulses modify the angiogenesis pattern.
High-energy extracorporeal shockwave therapy is an option in the treatment of orthopedic diseases such as chronic tendonitis. Despite its potential clinical applicability, there have been few studies on this technique that examine both its clinical effectiveness and its effect on angiogenesis.
High-energy extracorporeal shockwave therapy was applied at the tibial insertion of the left patellar ligament in 30 rabbits that were separated into six groups that differed in terms of the voltage and number of pulses that were applied by high-energy extracorporeal shockwave therapy. The tibial insertion in the right legs of the animals was used as the control. After six weeks, we performed histological analysis on the region and quantified the number of blood vessels.
No significant differences in the number of blood vessels between the left and right patellar tendons were found within groups. Additionally, no significant differences in the number of blood vessels in the left patellar tendons were found between groups.
The application of high-energy extracorporeal shockwave therapy did not cause a change in vascularization in the patellar tendon in rabbits.
PMCID: PMC3164413  PMID: 22179168
High-energy shock waves; Patellar ligament; Neovascularization; Animal model
19.  Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty 
Knee Surgery & Related Research  2014;26(4):214-221.
The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA).
Materials and Methods
We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed.
The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05).
In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups.
PMCID: PMC4258488  PMID: 25505703
Knee; Arthroplasty; Navigation; Optical and electromagnetic; Precision
20.  Electromagnetic Navigation for Thoracic Aortic Stent Graft Deployment: A Pilot Study in Swine 
The goal of this study was to determine the feasibility of electromagnetic tracking as a method to augment conventional imaging guidance for the safe delivery, precise positioning, and accurate deployment of thoracic aortic endografts.
Materials & Methods
Custom guidewires were fabricated and the delivery catheters for thoracic aortic endoprostheses (Gore TAG endoprostheses, W.L. Gore & Assoc. Inc., Flagstaff AZ) were retrofitted with integrated electromagnetic coil sensors enabling realtime endovascular tracking. Pre-procedure thoracic CTA were obtained after placement of fiducial skin patches on the chest wall of three anesthetized swine, enabling automatic registration. The stent graft deployment location target near the subclavian artery was selected on the pre-procedure CTA. Two steps were analyzed: advancing a tracked glidewire to the aortic arch, and positioning the tracked stent graft assembly using electromagnetic guidance alone. Multiple CT scans were performed to evaluate the accuracy of the electromagnetic tracking system by measuring the target registration error which compared the actual position of the tracked devices to the displayed “virtual” electromagnetic-tracked position. Post-deployment CTA and necropsy confirmed stent graft position and subclavian artery patency.
A stent graft was successfully delivered and deployed in each of the three animals using real-time electromagnetic tracking alone. The mean of the fiducial registration error of the auto-registration was 1.5 mm. Sixteen comparative scans were obtained to determine the target registration error, which was 4.3mm ± 0.97 mm (Range: 3.0 to 6.0mm) for the glidewire sensor coil. The target registration error for the stent graft delivery catheter sensor coil was 2.6 mm ± 0.7 mm (Range: 1.9 to 3.8 mm). The deployment error for the stent graft defined as deployment deviation from target was 2.6mm ± 3.0 mm.
Delivery and deployment of customized thoracic stent grafts is feasible and accurate in swine using electromagnetic tracking alone. Combining endovascular electromagnetic tracking with conventional fluoroscopy may further improve accuracy and be a more realistic multi-modality approach.
PMCID: PMC2875302  PMID: 20382032
21.  Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice 
Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and mortality. Based on the nature of primary injury following TBI, complex and heterogeneous secondary consequences result, which are followed by regenerative processes 1,2. Primary injury can be induced by a direct contusion to the brain from skull fracture or from shearing and stretching of tissue causing displacement of brain due to movement 3,4. The resulting hematomas and lacerations cause a vascular response 3,5, and the morphological and functional damage of the white matter leads to diffuse axonal injury 6-8. Additional secondary changes commonly seen in the brain are edema and increased intracranial pressure 9. Following TBI there are microscopic alterations in biochemical and physiological pathways involving the release of excitotoxic neurotransmitters, immune mediators and oxygen radicals 10-12, which ultimately result in long-term neurological disabilities 13,14. Thus choosing appropriate animal models of TBI that present similar cellular and molecular events in human and rodent TBI is critical for studying the mechanisms underlying injury and repair.
Various experimental models of TBI have been developed to reproduce aspects of TBI observed in humans, among them three specific models are widely adapted for rodents: fluid percussion, cortical impact and weight drop/impact acceleration 1. The fluid percussion device produces an injury through a craniectomy by applying a brief fluid pressure pulse on to the intact dura. The pulse is created by a pendulum striking the piston of a reservoir of fluid. The percussion produces brief displacement and deformation of neural tissue 1,15. Conversely, cortical impact injury delivers mechanical energy to the intact dura via a rigid impactor under pneumatic pressure 16,17. The weight drop/impact model is characterized by the fall of a rod with a specific mass on the closed skull 18. Among the TBI models, LFP is the most established and commonly used model to evaluate mixed focal and diffuse brain injury 19. It is reproducible and is standardized to allow for the manipulation of injury parameters. LFP recapitulates injuries observed in humans, thus rendering it clinically relevant, and allows for exploration of novel therapeutics for clinical translation 20.
We describe the detailed protocol to perform LFP procedure in mice. The injury inflicted is mild to moderate, with brain regions such as cortex, hippocampus and corpus callosum being most vulnerable. Hippocampal and motor learning tasks are explored following LFP.
PMCID: PMC3217637  PMID: 21876530
22.  Tissue Adhesives for Simple Traumatic Lacerations 
Journal of Athletic Training  2008;43(2):222-224.
Reference/Citation: Farion K, Osmond MH, Hartling L, et al. Tissue adhesives for traumatic lacerations in children and adults. Cochrane Database Syst Rev. 2001(4);CD003326.
Clinical Question: What is the clinical evidence base for tissue adhesives in the management of simple traumatic lacerations?
Data Sources: Studies were identified by searches of the following databases: Cochrane Wounds Group Specialized Trials Register (September 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (CDROM 2003, issue 3), MEDLINE (1966 to September 2003, week 1), EMBASE (1988 to 2003, week 36), Web of Science Science Citation Index (1975 to September 13, 2003) and various clinical trials registers (September 2003). Investigators and product manufacturers were contacted to identify additional eligible studies. The search terms included wounds and injuries, laceration, face injury, nose injury, tissue adhesives, and acrylates.
Study Selection: Each study fulfilled the following criteria: (1) The study was a randomized controlled trial that compared tissue adhesives with standard wound closure (SWC) (sutures, staples, adhesive strips) or tissue adhesive with tissue adhesive. (2) The wounds were acute, linear lacerations less than 12 hours old, resulting from blunt or sharp trauma. (3) The wound length, width, and depth allowed for approximation of the edges with minimal tension after deep sutures were placed, if required. Studies were included with no language or publication status restriction, with participants of any age recruited in an emergency department, outpatient clinic, walk-in clinic, or other primary care setting. Studies were excluded if the wounds were stellate lacerations, puncture wounds, mammalian bites, infected, heavily contaminated or devitalized, crossing joints or mucocutaneous junctions, in hair-bearing areas, or in patients with keloid formation or chronic illness.
Data Extraction: The characteristics of the study and participants, interventions, outcome measures, and findings were extracted by one author and verified by a second using a standard form. The primary measure was cosmetic outcome. Secondary measures were pain with the procedure, time to complete the procedure, and complications (erythema, infection, discharge, need for delayed closure, and dehiscence). Studies were divided into 2 groups as follows: group 1, comparisons among tissue adhesives with SWC, and group 2, comparisons among different tissue adhesives. All eligible studies were assessed for methodologic quality independently by 2 investigators using the Jadad Scale, which evaluates randomization, double blinding, withdrawals, and dropouts and is scored on a 5-point (maximum) scale. The data from the tissue adhesive and SWC studies were pooled and analyzed with a random-effects model. The I 2 statistic was used to determine heterogeneity among the studies. χ 2 analysis was performed to compare participant age, wound location, and type of tissue adhesive among the studies. The data from the studies comparing tissue adhesives were pooled and analyzed using a fixed-effects model.
Main Results: The search criteria identified 39 eligible studies, of which 11 met the inclusion criteria. In 10 studies, a tissue adhesive was compared with SWC. Five groups used butylcyanoacrylate, and 5 used octylcyanoacrylate. For SWC, 6 groups used sutures, 2 used adhesive strips, and 2 used a combination of methods, although most used sutures. Six studies were limited to pediatric patients and 2 to adult patients; 2 included patients of any age. Wounds were limited to facial lacerations in 2 pediatric studies and 1 group with patients of any age. Lacerations requiring deep sutures were excluded in 4 studies. One group compared tissue adhesives (butylcyanoacrylate and octylcyanoacrylate) among pediatric patients with facial lacerations not requiring deep sutures. In the 11 included studies, authors of 9 randomized and evaluated 1 laceration per patient, whereas 2 groups included patients with more than 1 laceration. In 1 group, each laceration was independently randomized and evaluated, and the other group randomized the patient and assigned all lacerations to a treatment group (tissue adhesive with SWC or tissue adhesive with tissue adhesive). The sample sizes ranged between 60 and 163 lacerations, and all 11 studies were performed in emergency departments.
The primary measure in all included studies was cosmetic outcome. The majority of groups used the Cosmetic Visual Analogue Scale, the Wound Evaluation Score, or a combination of these measures. Three groups measured cosmetic outcome with nonvalidated scoring systems. Assessment time periods were grouped and reported at (1) 5 to 14 days, (2) 1 to 3 months, and (3) 9 to 12 months after wound closure. Secondary outcomes were pain (as noted on visual analogue scale) and time to complete the procedure (as mean number of minutes). The 11 studies scored from 1 to 3 on the Jadad Scale. Adequate allocation concealment was reported in only 1 group.
Examining cosmetic outcome, 8 groups (565 lacerations) used the Cosmetic Visual Analogue Scale to compare tissue adhesives and SWC. The authors reported no significant differences in scores at the time periods of 5 to 14 days, 1 to 3 months, and 9 to 12 months. A subgroup analysis showed a significant ( P = .005) superiority of butylcyanoacrylate over SWC at 1 to 3 months. Using the Wound Evaluation Score, 4 studies (364 lacerations) compared tissue adhesives with SWC. No significant differences in cosmetic scores were found at 5 to 14 days, 1 to 3 months, or 9 to 12 months. One group (83 lacerations) compared butylcyanoacrylate with octylcyanoacrylate and reported no significant differences in cosmetic scores using the Cosmetic Visual Analogue Scale at 1 to 3 months and the Wound Evaluation Score at 5 to 14 days and 1 to 3 months.
Examining secondary outcomes, 6 groups (570 lacerations) compared tissue adhesives with SWC using the visual analogue scale for pain. Scores reported by parents, patients, physicians, and nurses significantly favored tissue adhesives. In 6 studies (584 lacerations), tissue adhesives were significantly favored over SWC in time to complete the procedure. For complication outcomes, 8 groups (727 lacerations) demonstrated significantly fewer incidences of erythema and an increased risk of dehiscence with tissue adhesives compared with SWC. No significant differences were shown for infection, delayed closure, or discharge. Among 83 lacerations, 1 group compared butylcyanoacrylate with octylcyanoacrylate and reported no significant differences in combined patient-reported and parent-reported visual analogue pain scores, time to complete the procedure, dehiscence, or infection.
Conclusions: This review provides evidence that tissue adhesives are an option to SWC (sutures, staples, adhesive strips) for the management of simple traumatic lacerations. Overall, no significant differences were found in cosmetic scores at the reported assessment periods between tissue adhesives and SWC. At 1 to 3 months, a subgroup analysis significantly favored butylcyanoacrylate over SWC. Tissue adhesives significantly lowered the time to complete the procedure, levels of pain, and rate of erythema. However, the data revealed a significant increase in the rate of dehiscence with the use of tissue adhesives when compared with SWC. The low methodologic quality of the evidence should be considered in the interpretation of the findings.
PMCID: PMC2267332  PMID: 18345349
wound closure; tissue bonding; open wounds
23.  Assessment of a Modified Acoustic Lens for Electromagnetic Shock Wave Lithotripters in a Swine Model 
The Journal of urology  2013;190(3):1096-1101.
The acoustic lens of the Siemens Modularis electromagnetic (EM) shock wave lithotripter has been modified to produce a pressure waveform and focal zone more closely resembling that of the original Dornier HM3 device. Herein, we assess the newly designed acoustic lens in vivo in an animal model.
Materials and Methods
Stone fragmentation and tissue injury produced by the original and modified lenses of a Siemens lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (~45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. For tissue injury assessment, shock wave-treated kidneys were perfused, dehydrated, cast in paraffin wax and sectioned. Digital images were captured every 120 µm and processed to determine the functional renal volume damage.
After 500 shocks, stone fragmentation efficiency produced by the original and modified lenses was 48 ± 12% and 52 ± 17% (p=0.60), respectively. However, after 2000 shocks, the modified lens showed significantly improved stone fragmentation of 86 ± 10%, compared to 72 ± 12% for the original lens (p=0.02). Tissue injury caused by the original and modified lenses was minimal at 0.57 ± 0.44% and 0.25 ± 0.25% (p=0.27), respectively.
With lens modification, the Siemens Modularis lithotripter demonstrates significantly improved stone fragmentation with minimal tissue injury at clinically relevant acoustic pulse energy. This new lens design could potentially be retrofitted to existing lithotripters, thereby improving the effectiveness of EM lithotripters.
PMCID: PMC3742623  PMID: 23485509
Lens modification; Electromagnetic Lithotripter; in vivo; Swine model
24.  Magnetic resonance imaging in patients with cardiac pacemakers: era of "MR Conditional" designs 
Advances in cardiac device technology have led to the first generation of magnetic resonance imaging (MRI) conditional devices, providing more diagnostic imaging options for patients with these devices, but also new controversies. Prior studies of pacemakers in patients undergoing MRI procedures have provided groundwork for design improvements. Factors related to magnetic field interactions and transfer of electromagnetic energy led to specific design changes. Ferromagnetic content was minimized. Reed switches were modified. Leads were redesigned to reduce induced currents/heating. Circuitry filters and shielding were implemented to impede or limit the transfer of certain unwanted electromagnetic effects. Prospective multicenter clinical trials to assess the safety and efficacy of the first generation of MR conditional cardiac pacemakers demonstrated no significant alterations in pacing parameters compared to controls. There were no reported complications through the one month visit including no arrhythmias, electrical reset, inhibition of generator output, or adverse sensations. The safe implementation of these new technologies requires an understanding of the well-defined patient and MR system conditions. Although scanning a patient with an MR conditional device following the strictly defined patient and MR system conditions appears straightforward, issues related to patients with pre-existing devices remain complex. Until MR conditional devices are the routine platform for all of these devices, there will still be challenging decisions regarding imaging patients with pre-existing devices where MRI is required to diagnose and manage a potentially life threatening or serious scenario. A range of other devices including ICDs, biventricular devices, and implantable physiologic monitors as well as guidance of medical procedures using MRI technology will require further biomedical device design changes and testing. The development and implementation of cardiac MR conditional devices will continue to require the expertise and collaboration of multiple disciplines and will need to prove safety, effectiveness, and cost effectiveness in patient care.
PMCID: PMC3219582  PMID: 22032338
25.  Tibial Bone Density in Athletes With Medial Tibial Stress Syndrome: A Controlled Study 
Medial tibial stress syndrome (MTSS) is a common overuse injury of the lower extremity predominantly observed in weight bearing activities. Knowledge about the pathological lesions and their pathophysiology is still limited. Only a single study was found to have investigated tibial bone density in the pain region, revealing lower density in athletes with long standing (range, 5-120 month) MTSS. In a follow-up study, bone density was determined to return to normal levels after recovery. The purpose of the present study was to investigate tibial bone density in athletes with shorter MTSS history (range, 3-10 weeks). A total of 11 athletes (7 males, 4 females) diagnosed with medial tibial stress syndrome were included in the study. The control group consisted of 11 regularly exercising individuals (7 males, 4 females). Tibial, femoral and vertebral bone densities were measured by dual energy x-ray absorptiometry. Total calcium intake was calculated by evaluating detailed nutrition history. No statistically significant differences were found in the tibial, femoral and vertebral bone densities between the groups. No statistically significant difference was found among groups, considering for calcium intake. Tibial bone densities were not lower in athletes with MTSS of 5.0 weeks mean duration (range, 3-10 weeks) compared to the healthy control group. Longitudinal studies with regular tibial bone density measurements in heavily trained athletes are necessary to investigate tibial density alterations in MTSS developing athletes during the course of the symptoms.
Key pointsTibial, femoral and vertebral bone densities were measured by dual energy x-ray absorptiometry.No differences were found between the MTSS group (MTSS history 3-10 weeks) and the healthy athletes group.
PMCID: PMC3761496  PMID: 24149568
Medial tibial stress syndrome; tibial bone density; calcium intake, athletes; exercise; bone mineral density; overuse injury

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