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This case report describes a novel and unique combination of both electromagnetic and electrohydraulic focused extracorporeal shockwave therapy (ESWT) and extracorporeal magnetotransduction therapy (EMTT) for accelerated healing in a calcaneus epiphyseal fracture with delayed healing in an adolescent Parkour athlete. After a 2.5m jump, the 14-year-old experienced significant heel pain, however avoided telling his parents. After eight weeks, the initial imaging using ultra low dose weight-bearing cone beam CT (WBCT) revealed a calcaneus non-union situation adjacent to the open calcaneal physis. To improve and accelerate bony healing substantially, we chose to apply both combined focused electromagnetic (Storz Ultra, Storz Medical AG, Tägerwillen, CH) and focused electrohydraulic (MTS, Konstanz, Germany) ESWT in a fractioned fashion plus EMTT (Storz Magnetolith, Tägerwillen, CH) in five consecutive weekly sessions while allowing the patient to fully weight bear. The follow-up WBCT after six weeks revealed a near to total healing of the delayed union and being pain-free. Notably, combination therapy with focused ESWT and EMTT did not result in early closure of the calcaneal epiphysis. We conclude that combined focused electromagnetic and electrohydraulic ESWT and EMTT facilitate bony healing in adolescent calcaneal apophyseal fractures without any adverse effects on the open physis. Evidence level IV (case report). [ABSTRACT FROM AUTHOR]

This work extends Doak's momentum potential theory to multi-chemical-component and reactive, time-stationary fluctuating flows. Additional mixture-related components are found to be superimposed on the canonical vortical, acoustic, and thermal parts of momentum fluctuations and total fluctuating enthalpy. These extended relations are used to develop a time-averaged model that relates the acoustic power radiated to the far-field with clearly defined vortical, acoustic, thermal, and compositional near-field sources. The resulting model is designed to offer a more general and comprehensive way to describe the noise generated within combustion chambers. [ABSTRACT FROM AUTHOR]

This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR) and plate resonators (PR) are investigated, which both deploy flexible materials with material inherent damping. In this context, a comprehensive experimental investigation was carried out focusing the identification and evaluation of various geometric parameters and material properties on the acoustics dissipation and related properties of various materials in a simplified setup of a single Helmholtz resonator with flexible walls (FHR concept). Furthermore, a parameter study based on analytical models was performed for both liner concepts, taking into account material as well as geometric parameters and their effects on transmission loss. In addition, design concepts that enable cylindrical or otherwise curved liner structures and the corresponding manufacturing technologies are presented, while considering essential structural features such as drainage. With respect to the potential application in jet engines, a structural–mechanical analysis considering the relevant load cases to compare and discuss the mechanical performance of a classical HR and the FHR concept liner is presented. Finally, both concepts are evaluated and possible challenges and potentials for further implementation are described. [ABSTRACT FROM AUTHOR]

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Many different pulsed electromagnetic field (PEMF) devises have been clinically used to stimulate healing processes, but many procedures are still without supporting basic research data. The aim of this study was to investigate a new modified pulsed electromagnetic field therapy: electromagnetic transduction therapy (EMTT). EMTT is technically based on high-intensive PEMFs with a magnetic field strength between 80 and 150 mT. The effect of EMTT for a 10-min session three times a week on human bone marrow mesenchymal stem cells (MSCs) was evaluated by assessing cell viability, gene expression of bone regenerative factors and VEGF-A (vascular endothelial growth factor) secretion after 7 and 14 days of treatment. No negative or toxic effects of EMTT on MSCs in vitro were observed in the applied test frame. The VEGF-ELISA at day 7 of EMTT treatment with 80 mT showed a significant higher VEGF concentration compared to untreated control group. In conclusion, high-intensive electromagnetic impulses showed no harmful effects on MSC cultures in our study. The enhancement of the proangiogenic factor VEGF in MSCs on day 7 indicates a substantial role in cell-stimulating effect of EMTT. Further in vitro and in vivo studies should differentiate specific stimulating and regenerating effects of EMTT impulses in soft tissue engineering. Specific electromagnetic characteristics have to be determined to optimize electromagnetic treatment options in orthopedic surgery and traumatology and soft tissue treatment options. [ABSTRACT FROM AUTHOR]

Dupuytren's disease is a progressive fibroproliferative disorder of the hand. In the nodular stage of Dupuytren's disease, pain might limit daily hand activities and progress to finger contractures. Focused electromagnetic high-energetic extracorporeal shockwave therapy (ESWT) may reduce pain in Dupuytren's nodules (Tubiana N). In this prospective, randomized, blinded, placebo-controlled single center trial, we enrolled 52 patients (mean age, 58.2 ± 9.2) with painful nodular Dupuytren disease Tubiana N. Randomization was done to either (group A) 3 treatments with focused electromagnetic high-energetic ESWT (2000 shots, 3 Hz, 0.35 mmJ/mm2/hand, Storz Duolith SD1, n = 27) or (group B) placebo ESWT (2000 shots, 3 Hz, 0.01 mJ/mm2/hand, n = 25) in a weekly interval. Primary outcome was the level of pain on a visual analogue scale (VAS 0–10) at 3/6/12/18 months, secondary outcomes were patient-related outcome measures (DASH score, MHQ score, URAM scale), grip strength, patient's satisfaction, and Dupuytren's disease progression over 18 months follow-up. Focused ESWT significantly improved outcomes. Pain was reduced from 3.6 ± 1.8 to 1.9 ± 1.2 at three, to 1.4 ± 0.7 at six, to 1.7 ± 1.6 after 12 months and 1.9 ± 0.8 after 18 months in the intervention group (47% reduction, p < 0.05). In the placebo group, pain on VAS increased from 2.2 ± 1.4 to 3.4 ± 1.7 at three, to 3.4 ± 1.8 at six, to 3.4 ± 1.4 at 12 and 3.1 ± 1.1 at 18 months (35% increase, p < 0.05). Quality-of-life score tended to improve in the intervention group (MHQ, 77 ± 19 to 83 ± 12; DASH, 12 ± 18 to 10 ± 9) while it deteriorated in the placebo group as Dupuytren's disease was progressing (MHQ, 79 ± 15 to 73 ± 17; DASH, 6 ± 10 to 14 ± 13). The strength of the affected hand and fingers did not change significantly in either of the groups. Patients' satisfaction was higher in the intervention group for symptom improvement (56% vs. 12%) and reduction of disease progression (59% vs. 24%). Any Dupuytren-related intervention was performed in 26% in the intervention group and in 36% in the placebo group within 18 months of follow-up (n.s.). Focused electromagnetic high-energetic ESWT can significantly reduce pain in painful nodules in Dupuytren's disease in an 18-month perspective. (ClinicalTrials.gov Identifier: NCT01184586). [ABSTRACT FROM AUTHOR]

This paper presents the contribution from the German Aerospace Center (DLR) to the first liner benchmark challenge under the framework of the International Forum for Aviation Research (IFAR). Therefore, two sets of acoustically damping wall treatments, called 'liner samples', have been produced by additive manufacturing based on the design data provided by NASA coordinating this benchmark. These liner samples have been integrated and acoustically characterized in the liner flow test facility DUCT-R at DLR Berlin as well as in the liner flow test facility GFIT at NASA Langley. Besides the dissipation coefficients and the axial pressure profiles, the liner wall impedance was educed by first determining the axial wave numbers and then applying a straightforward method based on the one-dimensional Convected Helmholtz Equation. Finally, the comparison of the liner impedance values to the NASA results show a fairly good agreement. [ABSTRACT FROM AUTHOR]

Measurements of sound due to swirl–nozzle interaction are presented. In the experiment a swirl structure was generated by means of unsteady tangential injection into a steady swirl-free flow upstream from a choked convergent–divergent nozzle. Ingestion of swirl by the choked nozzle caused a mass-flow rate change, which resulted in a downstream-measured acoustic response. The downstream acoustic pressure was found to remain negative as long as the swirl is maintained and reflections from the open downstream pipe termination do not interfere. The amplitude of this initial acoustic response was found to be proportional to the square of the tangential mass-flow rate used to generate swirl. When the tangential injection valve was closed, the mass-flow rate through the nozzle increased, resulting in an increase of the downstream acoustic pressure. This increase in signal was compared to the prediction of an empirical quasi-steady model, constructed from steady-state flow measurements. As the opening time of the valve was varied, the signal due to swirl evacuation showed an initial overshoot with respect to quasi-steady behavior, after which it gradually decayed to quasi-steady behavior for tangential injection times long compared to the convection time in the pipe upstream of the nozzle. This demonstrates that the acoustic signal can be used to obtain quantitative information concerning the time dependence of the swirl in the system. This could be useful for understanding the dynamics of flow in engines with swirl-stabilized combustion. [ABSTRACT FROM AUTHOR]

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Rotator cuff (RC) tendinopathy is the most common cause of shoulder pain. The effectiveness of electromagnetic transduction therapy (EMTT), a high energetic pulsed electromagnetic field therapy in this field has not been tested yet in combination with extracorporeal shock wave therapy (ESWT). A total of 86 patients with RC tendinopathy were randomized to undergo three sessions of ESWT in combination with 8 sessions of EMTT or sham-EMTT. Both intervention groups experienced significant and clinical relevant decrease of pain at all follow-up visits, and the functionality of the shoulder evaluated by the Constant Murley score increased significantly as well. The combination of EMTT + ESWT produced significantly greater pain reduction in the visual analogue scale compared to ESWT with sham-EMTT after 24 weeks, during which the Constant Murley score improved significantly when the combination of ESWT and EMTT was employed. In patients with RC tendinopathy, electromagnetic transduction therapy combined with extracorporeal shock wave therapy significantly improves pain and function compared to ESWT with sham-EMTT. [ABSTRACT FROM AUTHOR]

In aero engines, noise absorption is realised by acoustic liners, e.g., Helmholtz resonator (HR) liners, which often absorb sound only in a narrow frequency range. Due to developments of new engine generations, an improvement of overall acoustic damping performance and in particular more broadband noise absorption is required. In this paper, a new approach to increase the bandwidth of noise absorption for HR liners is presented. By replacing rigid cell walls in the liner's honeycomb core structure by flexible polymer films, additional acoustic energy is dissipated. A manufacturing technology for square honeycomb cores with partially flexible walls is described. Samples with different flexible wall materials were fabricated and tested. The acoustic measurements show more broadband sound absorption compared to a reference liner with rigid walls due to acoustic-structural interaction. Manufacturing-related parameters are found to have a strong influence on the resulting vibration behaviour of the polymer films, and therefore on the acoustic performance. For future use, detailed investigations to ensure the liner segments compliance with technical, environmental, and life-cycle requirements are needed. However, the results of this study show the potential of this novel liner concept for noise reduction in future aero-engines. [ABSTRACT FROM AUTHOR]

Copyright of Obere Extremitat is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: In Achilles tendon injuries, it is suggested that a pathological continuum might be evident from the healthy Achilles tendon to Achilles tendinopathy to Achilles tendon rupture. As such, risk factors for both tendinopathy and rupture should be the same. Hypothesis: Hereditary and medical risk factors for Achilles tendinopathy and Achilles tendon rupture are the same to a similar extent in a matched pair analysis. Design: Matched pair study; level of evidence: 3. Setting: Recreational sportsmen as well as athletes on national level. Patients: 566 questionnaires were analysed. 310 subjects were allocated to 3 groups (A, B, C) after matching the pairs for age, weight, height and gender: (A) healthy Achilles tendons ( n = 89, age 39 ± 11 years, BMI 25.1 ± 3.9, females 36%), (B) chronic Achilles tendinopathy ( n = 161, age 41 ± 11 years, BMI 24.4 ± 3.7, females 34%), (C) acute Achilles tendon rupture ( n = 60, age 40 ± 9 years, BMI 25.2 ± 3.2, females 27%). Results: We found a positive family history of Achilles tendinopathy as a risk factor for Achilles tendinopathy (OR: 4.8, 95% CI: 1.1-21.4; p = 0.023), but not for Achilles tendon rupture (OR: 4.0, 95% CI 0.7-21.1, p = 0.118). Smoking and cardiac diseases had a lower incidence in Achilles tendinopathy than in healthy subjects (both p = 0.001), while cardiovascular medication did not change the risk profile. Conclusion: Identifying risk factors associated with Achilles tendon disorders has a high clinical relevance regarding the development and implementation of prevention strategies and programs. This cross-sectional study identified a positive family history as a significant solitary risk factor for Achilles tendinopathy, increasing the risk fivefold. However, in this matched pair analysis excluding age, weight, height and gender as risk factors no further factor necessarily increases the risk for either Achilles tendinopathy or Achilles tendon rupture. [ABSTRACT FROM AUTHOR]

Objective The quality of reporting in congress abstracts is likely to influence clinical decision-making. Hypothesis The quality of reporting in sports injury prevention abstracts has increased over the last 3 years, as did the number of randomised controlled trials (RCT). Methods 154 abstracts from the 2005 and 186 abstracts from 2008 World Conferences on Sports Injury Prevention in Norway were analysed. Main outcome measures Scores of 17 Consolidated Standards of Reporting Trials (CONSORT) criteria for RCT, or 22 Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria for observational studies were determined. Results Improvement in reporting was evident in RCT (CONSORT score 5.8±0.9 vs 8.6±2.9, p=0.001, Cl -4.29 to -1.43) as well as for observational studies (STROBE score 7.9±1.6 vs 9.9±1.7, p<0.001, Cl -2.34 to -1.53) between 2005 and 2008. RCTs were published in 9.1% in 2005 versus 10.2% in 2008 (p=0.727). RCT demonstrated a significant improvement in main outcome (0% vs 57.9%, p<0.001). For observational studies, a significant improvement was reported in rationale (53.5% vs 98.2%, p<0.001), objectives (82.2% vs 95.1%, p=0.012), study design (25.2% vs 65%, p<0.001), setting (43.7% vs 65.6%, p=0.002), variables (20.7% vs 74.2%, p<0.001), participants (0.7% vs 10.4%, p=0.001) and funding (0% vs 5.5%, p=0.006). Conclusion While the percentage of published RCTs in abstracts at the World Congress of Sports Injury Prevention remained unchanged, an improvement in reporting of abstracts was evident from 2005 to 2008, as determined by CONSORT/STROBE criteria. However, substantial and comprehensive use of the CONSORT and STROBE criteria might further increase the quality of reporting of sports injury conference abstracts in the future. [ABSTRACT FROM AUTHOR]

Purpose: A postoperative defect of the surrounding soft tissue is one main risk factor for implant exposure and infection following total knee arthroplasty (TKR). The main factors that promote infection, tissue ischemia, and hypoxia are strongly associated with arterial insufficiency and the prevalence of impaired peripheral perfusion. We hypothesized that vascular malperfusion is the predisposing reason for soft tissue complications following TKR necessitating plastic reconstructive surgery. Methods: A retrospective chart review was made among patients ( n = 12) with soft tissue defects due to wound infection following a total knee arthroplasty referred to plastic reconstructive surgery. All patients presented with an exposed implant, and angiographic imaging was performed prior to reconstructive procedures. Results: Eight out of twelve patients (67%) had a pathological vascular status. In three of these patients, interventional procedures were performed to ameliorate perfusion. In ten patients (83%), the defect was covered with a plastic reconstructive regional or free tissue transfer. Four patients received a free latissimus dorsi flap and six patients a pedicled a gastrocnemius muscle flap. In one patient, a secondary wound closure was needed after knee arthrodesis and an amputation was performed in another patient due to a multiresistant staphylococcus aureus infection and massive tissue destruction at the time of admission. Conclusions: We suggest to rule out peripheral occlusive disease among patients undergoing TKR at best prior to orthopedic surgery using pulses and, if in doubt ankle-brachial index and doppler sonography Consequently, if vascular occlusions are then confirmed by angiography, dilatation and stenting or revascularization should be performed, to ameliorate perfusion. Level of evidence: Retrospective case series with no comparison groups, Level IV. [ABSTRACT FROM AUTHOR]

Purpose: Cryotherapy and compression as integral part of the RICE regimen are thought to improve treatment outcome after sport injuries. Using standardized cryotherapy and compression perioperatively has been reported with conflicting clinical results. The impact of combined cryotherapy and compression is compared to standard care among patients undergoing wrist arthroscopy. Methods: Fifty-six patients undergoing wrist arthroscopy were assessed, 54 patients were randomized to either Cryo/Cuff™ (3 × 10 min twice daily) or standard care over 3 weeks. Follow-up clinical visits were at postoperative days 1, 8, and 21. One patient in each group was lost during follow-up. Fifty-two patients were analyzed. Statistics were performed as Intention-to-treat analysis. Outcome parameters were pain, three-dimensional volume of the wrist, range of motion, and DASH score. Results: The Cryo/Cuff™ group had a 49% reduction in pain level (VAS 3.5 ± 0.4 vs. VAS 1.8 ± 0.2 on the 21st postoperative day) when compared to a reduction of 41% in the control group (VAS 5.1 ± 0.6 preoperatively vs. VAS 3.0 ± 0.5 on the 21st postoperative day). Swelling and range of motion were not as significantly different between the two groups as were DASH scores (DASH-score Cryo/Cuff group preoperatively 37.3 ± 3.5 and postoperatively 36.9 ± 3.5; DASH-score control group preoperatively 42.8 ± 4.3 and postoperatively 41.9 ± 4.9). The CONSORT score reached 17 out of 22. Conclusion: There was no significant effect of additional home-based combined cryotherapy and compression using the Cryo/Cuff™ wrist bandage, following wrist arthroscopy regarding pain, swelling, range of motion, and subjective impairment assessed using the DASH score over 3 weeks in comparison with the control group. [ABSTRACT FROM AUTHOR]

Topical glyceryl trinitrate treatment has demonstrated short- to mid-term efficacy in chronic noninsertional Achilles tendinopathy. However, the underlying mechanisms are far from being understood. We hypothetized that Achilles tendon capillary blood flow changes immediately after topical glyceryl trinitrate treatment. Fifteen patients (55 ± 15 years, VAS 5.8 ± 2.3) with current mid-portion Achilles tendon pain 36 months after open surgical Achilles tendon repair for tendon rupture were included. On the Achilles mid-portion, 1.2 mg topical glyceryl trinitrate was sprayed. Microcirculatory monitoring included capillary blood flow, tendon oxygen saturation and postcapillary venous filling pressures at the insertion and 2, 4 and 6 cm above the insertion using a combined laser Doppler and spectrophotometry system. Baseline capillary blood-flows of the painful versus the uninjured tendon were increased [108 ± 46 vs. 81 ± 20 (2 cm above the insertion), 104 ± 40 vs. 76 ± 20 (4 cm above the insertion), 111 ± 53 vs. 90 ± 21 (6 cm above the insertion, P < 0.05)]. However, topical glyceryl trinitrate did not change capillary blood-flow at 2 and 8-mm tissue depths at the painful Achilles tendon or the healthy tendon. Tendon oxygenation was not changed at the painful or the healthy Achilles tendon. Postcapillary venous filling pressure was reduced at 8 mm at the mid-portion in the painful Achilles tendon only (113 ± 37 vs. 95 ± 31, P = 0.030). Acute topical glyceryl trinitrate facilitates capillary venous outflow in painful Achilles tendons. However, capillary blood-flow and tendon oxygenation remain unchanged following acute topical glyceryl trinitrate application. Elevated capillary blood-flow at the entire mid-portion is encountered at baseline in previously ruptured painful Achilles tendons even 3 years after surgical repair of the Achilles tendon indicating an altered microcirculatory flow pattern. [ABSTRACT FROM AUTHOR]

The role of gender in Achilles tendinopathy is yet to be determined. We hypothesized that female patients respond the same as males to 12 weeks of painful eccentric training. A total number of 75 consecutive mid-portion patients with Achilles tendinopathy (25 females, 38 males) were enrolled in a cohort study with 63 being analyzed after 12 weeks according to their gender for tendon and paratendon microcirculatory mapping. Outcome was determined by pain on visual analogue scale, VISA-A score, Foot Ankle Outcome Score (FAOS), tendon and paratendon capillary blood flow, oxygen saturation, and postcapillary venous filling pressures. Eccentric training resulted in a morning resting pain reduction by 44% in males ( P = 0.001) and by 27% in females ( P = 0.08). VISA-A score improved in males by 27% from 63 ± 12 to 86 ± 13 ( P = 0.036) and by 20% in females from 60 ± 14 to 75 ± 11 ( P = 0.043, P < 0.05 for gender difference). Among females, only one out of five FAOS items was increased (sport 72 ± 21 to 82 ± 15, P = 0.045), while in males, four out of five items were increased (symptoms, pain, all-day-life, and sport, all P < 0.01). The microcirculatory gender-specific response to eccentric training revealed a greater postcapillary venous filling pressure reduction among symptomatic females and inconclusive capillary blood flow changes. No change in tendon oxygenation was noted in both genders. Symptomatic females suffering Achilles tendinopathy do not benefit as much as symptomatic males from 12 weeks of eccentric training. The pain reduction is significantly lower among symptomatic females in contrast to males, and the improvement in the FAOS and VISA-A scores is significantly lower among females in contrast to males. Additional treatment options warrant scrutiny to symptomatic females suffering Achilles tendinopathy beyond eccentric training. [ABSTRACT FROM AUTHOR]

Background: Press-fit fixation of a tendon graft has been advocated to achieve tendon-to-bone healing. Hypothesis: Fixation of hamstring tendon grafts with a porous bone scaffold limits bone tunnel enlargement compared with a biodegradable interference screw fixation. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Between 2005 and 2006, 20 patients (17 men, 3 women) with a primary reconstruction of the anterior cruciate ligament (ACL) were enrolled in this study. Patients were randomized to obtain graft fixation in the tibial tunnel either by means of an interference screw (I) or a press-fit fixation with a porous bone cylinder (P). At 3 months after surgery, a computed tomography (CT) scan of the knee was performed, and tunnel enlargement was analyzed in the coronal and sagittal planes for the proximal, middle, and distal thirds of the tunnel. After 6 months and 1 and 2 years, radiographs of the knee in the sagittal and coronal plane were analyzed for bone tunnel widening. The International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores of both groups were compared after 1 and 2 years. Results: The bone tunnel enlargement determined by CT was 106.9% ± 10.9% for group P and 121.9% ± 9.0% for group I (P< .02) in the anteroposterior (AP) plane and 102.8% ± 15.2% versus 121.5% ± 10.1% in the coronal plane (P<.01). The IKDC, Tegner, and Lysholm scores improved in both groups from preoperatively to postoperatively without significant differences between the 2 groups. There was a trend to higher knee stability in group P after 3 months (0.6 ± 1.4 mm vs 1.8 ± 1.5 mm; P = .08). Conclusion: Both interference screw and a press-fit fixation lead to a high number of good or very good outcomes after ACL reconstruction. Tibial press-fit fixation decreases the amount of proximal bone tunnel enlargement. [ABSTRACT FROM AUTHOR]

Background: Cellulite is a widespread problem involving females' buttocks and thighs based on the female specific anatomy. Given the higher number of fat cells stored in female fatty tissue in contrast to males, and the aging process of connective tissue leads to an imbalance between lipogenesis and lipolysis with subsequent large fat cells bulging the skin. In addition, microcirculatory changes have been suggested, however remain largely unknown in a controlled clinical setting. We hypothesize that the combination of extracorporeal shockwave and a daily gluteal muscle strength program is superior to the gluteal muscle strength program alone in cellulite. Methods/Design: Study design: Randomized-controlled trial. IRB approval was granted at Hannover Medical School, Germany on May 22, 2009. For allocation of participants, a 1:1 ratio randomization was performed using opaque envelopes for the concealment of allocation. Reporting: according to CONSORT 2010. Eligible patients were females aged 18 or over and 65 or younger with cellulite with documented cellulite 1°-4° according to the Nürnberger score. Exclusion criteria were suspected or evident pregnancy, no cellulite, no informed consent or age under 18 years or above 65 years. Patients were recruited by advertisements in local regional newspapers and via the Internet. Analysis: Intention-to-treat. Outcome parameters: a) Photonumeric severity scale, b) Nürnberger Score, c) circumference measurements, d) capillary blood flow, e) tissue oxygen saturation, f) postcapillary venous blood flow. Intervention group: Six sessions of extracorporeal focused shock wave for six sessions (2000 impulses, 0,25 mJ/m2 every 1-2 weeks) at both gluteal and thigh regions plus a specific gluteal strength exercise training. Control group: Six sessions of sham extracorporeal focused shock wave for six sessions (2000 impulses, 0,01 mJ/m2 every 1-2 weeks) at both gluteal and thigh regions plus a specific gluteal strength exercise training. Follow-up: 12 weeks. Blinding was achieved for all participants enrolled in the trial, the photograph taking the digital images for the primary outcome measure, the two assessors of the outcome measures, all additional health care providers and for the analyst from the biometrical department. Only one researcher (BJ) was aware of the group assignment performing the randomisation and the extracorporeal shock wave therapy. Discussion: This randomised-controlled trial will provide much needed evidence on the clinical effectiveness of focused extracorporal shock wave therapy as an adjunct to gluteal strength training in females suffering cellulite. ClinicalTrials.gov identifier: NCT00947414. [ABSTRACT FROM AUTHOR]

Controversy exists in the literature regarding the most appropriate treatment for anterior cruciate ligament (ACL) ruptures in the skeletally immature patient. To study the histological and biomechanical stages following ACL reconstruction during growth, it is necessary to establish an equivalent model to replicate the situation of an immature skeleton. In the present study we evaluated a large animal model of ACL reconstruction during growth using skeletally immature sheep. In contrast to existing models we did not intend to provoke growth disturbances. Instead, we identified those criteria known to be essential to prevent growth disturbances in the human situation and transformed them into an animal model. Applying those criteria to skeletally immature sheep at an age of four months, we performed a fully transphyseal ACL reconstruction of their right knee. The contralateral knee served as a control. The sheep were then sacrificed 3, 6, 12 and 24 weeks after surgery. This animal model is described in detail in the present manuscript. Basic science data are presented in order to 1) make it easier for other research groups to study ACL reconstruction during growth using our model and 2) to improve this model by modifying the one or other detail of the proposed technique. Using this model, remaining open questions concerning ACL reconstruction during growth can be addressed in future studies. [ABSTRACT FROM AUTHOR]

Background: A soccer-specific balance training has been shown to decrease injury incidence of the anterior cruciate ligament and ankle sprains in randomized controlled trials. However, hamstring injuries and tendinopathy remain significant issues in soccer. Hypothesis: Proprioceptive training can reduce the incidence of hamstring muscle injuries and tendinopathy in elite soccer. There is a dose-effect relationship between balance training duration and injury incidence. Study Design: Cohort study; Level of evidence, 3. Methods: Twenty-four elite female soccer players (body mass index, 21.7 ± 1.2; age, 21 ± 4 years) of a German premier league soccer team were prospectively included. Starting in January 2004, an additional soccer-specific proprioceptive multistation training was initiated over 3 years. Injury data/1000 hours of exposure with documentation of all occurred injuries, detailed training, and match exposure data as well as time loss data were 100% complete. Results: At the end of the 3-year proprioceptive balance training intervention, noncontact hamstring injury rates were reduced from 22.4 to 8.2/1000 hours (P = .021), patellar tendinopathy from 3.0 to 1.0/1000 hours (P = .022), and Achilles tendinopathy from 1.5 to 0.0/1000 hours (P = .035). There was no effect of balance training on contact injuries. Mean time loss of all assessed injuries significantly decreased from 14.4 days during the control period to 1.5 days during intervention periods (P = .003). The more minutes of balance training performed, the lower the rate of overall injuries (r = -0.185, P = .001), hamstring injuries (r = -0.267, P = .003), patellar tendinopathy (r = -0.398, P = .02), and gastrocnemius strains (r = -0.342, P = .002). Conclusion: Soccer-specific balance training (protective balancing) can reduce noncontact hamstring injuries and patellar and Achilles tendinopathy. A dose-effect relationship between duration of balance training and injury incidence is evident. A proprioceptive training program reduced the rehabilitation time in noncontact injuries, which warrants further investigation. [ABSTRACT FROM AUTHOR]

Copyright of Operative Orthopädie und Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: There is a lot of controversy in the recent literature with regard to the optimal treatment of anterior cruciate ligament (ACL) injuries during growth. latrogenic growth disturbance due to physeal damage is a potential complication, forcing many orthopaedic surgeons to treat these injuries conservatively. Hypothesis: It is possible to perform a fully transphyseal AOL reconstruction in an ovine model with wide-open physes without creating growth disturbances. Study Design: Descriptive laboratory study. Materials and Methods: Four-month-old skeletally immature sheep underwent a transphyseal AOL reconstruction of the right knee. The surgical technique followed the criteria known to be essential to avoid growth disturbances in humans; the tibial tuberosity was spared to prevent a genu recurvatum, thermal damage to the growth plates was avoided, the physes were perforated with a smalldiameter drill in the center of the growth plate, a soft tissue graft was used, graft fixation was achieved far away from the growth plates, the perforated growth plates were filled by the soft tissue graft, and the graft was moderately pretensioned before fixation. The left knee served as a control. A computer-assisted evaluation of long radiographs (frontal and sagittal plane) of the exarticulated hindlimbs was performed to exactly evaluate the limb alignment, joint orientation, and leg length. The animals were sacrificed in groups of 6 after 3, 6, 12, and 24 weeks. Results: No angular deformities or leg-length discrepancies occurred after this transphyseal AOL reconstruction procedure throughout the remaining growth. Conclusion: This large-animal study supports the clinical observation that it is possible to perform an AOL reconstruction without creating growth disturbances as long as a number of key principles are followed. Clinical Relevance: Previous animal studies argued against AOL reconstruction in skeletally immature patients. This largeanimal study provides support for early operative treatment of AOL ruptures even in young patients with open physes. [ABSTRACT FROM AUTHOR]

Background: The effect of combined cryotherapy/compression versus cryotherapy alone on the Achilles tendon is undetermined. Hypothesis: Standardized combined cryotherapy/compression changes in midportion Achilles tendon microcirculation are superior to those with cryotherapy during intermittent application. Study Design: Controlled laboratory study. Methods: Sixty volunteers were randomized for either combined cryotherapy/compression (Cryo/Cuff, DJO Inc, Vista, California: n = 30; 32 ± 11 years) or cryotherapy alone (KoldBlue, TLP Industries, Kent, United Kingdom: n = 30; 33 ± 12 years) with intermittent 3 × 10-minute application. Midportion Achilles tendon microcirculation was determined (O2C, LEA Medizintechnik, Giessen, Germany). Results: Both Cryo/Cuff and KoldBlue significantly reduced superficial and deep capillary tendon blood flow within the first minute of application (43 ± 46 arbitrary units [AU] vs 10 ± 19 AU and 42 ± 46 AU vs 12 ± 10 AU; P = .0001) without a significant difference throughout all 3 applications. However, during recovery, superficial and deep capillary blood flow was reestablished significantly faster using Cryo/Cuff (P = .023). Tendon oxygen saturation was reduced in both groups significantly (3 minutes Cryo/Cuff: 36% ± 20% vs 16% ± 15%; KoldBlue: 42% ± 19% vs 28% ± 20%; P < .05) with significantly stronger effects using Cryo/Cuff (P = .014). Cryo/Cuff led to significantly higher tendon oxygenation (Cryo/Cuff: 62% ± 28% vs baseline 36% ± 20%; P = .0001) in superficial and deep tissue (Cryo/Cuff: 73% ± 14% vs baseline 65% ± 17%; P = .0001) compared with KoldBlue during all recoveries. Postcapillary venous filling pressures were significantly reduced in both groups during application; however, Cryo/Cuff led to significantly, but marginally, lower pressures (Cryo/Cuff: 41 ± 7 AU vs baseline 51 ± 13 AU; P = .0001 and KoldBlue: 46 ± 7 AU vs baseline 56 ± 11 AU; P = .026 for Cryo/Cuff vs KoldBlue). Conclusion: Increased tendon oxygenation is achieved as tendon preconditioning by combined cryotherapy and compression with significantly increased tendon oxygen saturation during recovery in contrast to cryotherapy alone. Both regimens lead to a significant amelioration of tendinous venous outflow. Clinical Relevance: Combined cryotherapy and compression is superior to cryotherapy alone regarding the Achilles tendon microcirculation. Further studies in tendinopathy and tendon rehabilitation are warranted to elucidate its value regarding functional issues. [ABSTRACT FROM AUTHOR]

Osteochondral transplantations, albeit technically challenging, appear promising not only in knee joint lesions, but also in the treatment of talus lesions. We hypothesized that in patients suffering osteochondral lesions of the talus, favorable outcomes are obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty. Over a 3-year period (1998–2001), 14 patients (six male, eight female, median age 22 years) were treated with an autologous osteochondral transplantation of the talus. Eight patients were previously untreated (group I). Six patients had previous ankle procedures, such as microfracturing (group II). The median follow-up was 24 months and 100% complete at 12 months. The functional outcome was evaluated at least at 6 weeks, 12 weeks, and 1 year after surgery using pain on a visual analog scale (VAS) and sports activity was recorded at 1 year after surgery. In ten patients, magnetic resonance imaging (MRI) of the ankle was performed at 1 year after surgery (group I/II: 7/3). Overall ankle pain was decreased from 6.9 ± 2.1 to 4.0 ± 2.8 postoperatively. The mean knee pain for the donor knee was 2.6 ± 2.4. We found no significant difference between the primary mosaicplasty group and the secondary mosaicplasty group with regard to pain. MRI scans of ten patients showed a complete incorporation of the osteochondral cylinders at 1 year after surgery. Favorable outcomes were obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty. We found no significant difference among patients with previous ankle surgery in contrast to those without, with a median 24-months follow-up. [ABSTRACT FROM AUTHOR]

Background: Higher estrogen levels in women seem to play a role regarding an increased ligament and tendon injury rate among women. However, gender differences of tendon microcirculation have not yet been reported. Hypothesis: Female patients suffering Achilles tendinopathy have worse tendon and paratendon microcirculation than symptomatic male patients. Study Design: Cross-sectional study; Level of evidence, 2. Methods: A total of 139 Achilles tendinopathy patients (58 women, 81 men) were analyzed according to their gender for tendon and paratendon microcirculation by mapping at 12 positions (4 tendons, 8 paratendons) in each limb. Tendon and paratendon capillary blood flow, oxygen saturation, and postcapillary venous filling pressures were measured at 2-mm and 8-mm tissue depths. Results: Symptomatic women had similarly elevated tendon capillary blood flow as men at 4 Achilles tendon positions. However, distal medial (83 ± 40 vs 105 ± 74, P < .05) and lateral (98 ± 49 vs 121 ± 74) paratendon capillary blood flow were significantly lower among men. Symptomatic female patients had superior tendon and paratendon oxygen saturation at 11 of 12 positions (P < .05) as well as reduced postcapillary venous filling pressures at the proximal midportion tendon (55 ± 17 vs 63 ± 20, P < .05) and paratendon (69 ± 19 vs 77 ± 26) location. Pain level was not different between female (5.3 ± 2.2) and male patients (5.4 ± 2, P = .864). Female patients had significantly higher Foot and Ankle Outcome Sports Scores (71 ± 22 vs 64 ± 23 in the men, P = .041), while 4 out of 5 other Foot and Ankle Outcome Score items were not different. Conclusion: Symptomatic female patients have similarly elevated tendon capillary blood flow compared with symptomatic male patients suffering Achilles tendinopathy, but superior tendon and paratendon oxygen saturations and reduced postcapillary venous filling pressures indicate better tendon and paratendon Achilles tendon microcirculation in women. [ABSTRACT FROM AUTHOR]

Tendinopathy is of distinct interest as it describes a painful tendon disease with local tenderness, swelling and pain associated with sonographic features such as hypoechogenic texture and diameter enlargement. Recent research elucidated microcirculatory changes in tendinopathy using laser Doppler flowmetry and spectrophotometry such as at the Achilles tendon, the patellar tendon as well as at the elbow and the wrist level. Tendon capillary blood flow is increased at the point of pain. Tendon oxygen saturation as well as tendon postcapillary venous filling pressures, determined non-invasively using combined Laser Doppler flowmetry and spectrophotometry, can quantify, in real-time, how tendon microcirculation changes over with pathology or in response to a given therapy. Tendon oxygen saturation can be increased by repetitive, intermittent short-term ice applications in Achilles tendons; this corresponds to 'ischemic preconditioning', a method used to train tissue to sustain ischemic damage. On the other hand, decreasing tendon oxygenation may reflect local acidosis and deteriorating tendon metabolism. Painful eccentric training, a common therapy for Achilles, patellar, supraspinatus and wrist tendinopathy decreases abnormal capillary tendon flow without compromising local tendon oxygenation. Combining an Achilles pneumatic wrap with eccentric training changes tendon microcirculation in a different way than does eccentric training alone; both approaches reduce pain in Achilles tendinopathy. The microcirculatory effects of measures such as extracorporeal shock wave therapy as well as topical nitroglycerine application are to be studied in tendinopathy as well as the critical question of dosage and maintenance. Interestingly it seems that injection therapy using color Doppler for targeting the area of neovascularisation yields to good clinical results with polidocanol sclerosing therapy, but also with a combination of epinephrine and lidocaine. [ABSTRACT FROM AUTHOR]

Stress fractures occur in normal bone due to mechanical overload by cyclic stress increasing the osteoclastic activity, thus facilitating weakening leading to fracture of bones. Long-distance running may lead to stress fractures of the mid- and distal tibia and of the metatarsal bones. Stress fractures to the sacrum are rare. Certain factors for stress fractures in runners have been identified, such as leg–length inequality, a high longitudinal arch of the foot, forefoot varus, and menstrual irregularities in case of female athlete triad. We report on a 22-year-old female runner (usually training 140 km/week) suffering a sacral fatigue-type fracture. The female athlete triad with eating disorders, dysmenorrhea, and osteopenia was ruled out. Sexual hormone blood samples proofed normal values. The diagnosis was performed using magnetic resonance imaging 2 weeks after the onset of buttock pain. A conservative treatment regimen was initiated with strict physical rest for the first 2 weeks, and then gradual increase of physical activity with 60–90 min of daily cycling and moderate 2 × 60 min cross-training. After another 2 weeks time, daily 60–90 min of walking, Nordic pole walking, and moderate strength training two times a week was performed. At 7 weeks running was started, gradually increased to 90 km/week without any pain. A rapid rehabilitation programme after sacral stress fractures involving low impact physical activity, such as Walking and Nordic pole walking, is applicable to female athletes after ruling out the female athlete triad. [ABSTRACT FROM AUTHOR]

Background: Cryotherapy and compression have been shown to decrease pain and improve function. The dosage and timing of these options remain unclear. Purpose: To examine the effects of a standardized compression and cryotherapy device (Cryo/Cuff) on midportion Achilles tendon microcirculation during intermittent administration. Study Design: Descriptive laboratory study. Methods: Twenty-six subjects were included (13 men and 13 women; age, 32.3 ± 12 years; body mass index, 25.4 ± 5 kg/m²). Each underwent three 10-minute applications of the device, followed by a 10-minute recovery period. A continuous real-time assessment of parameters of Achilles tendon midportion microcirculation was performed with a laser Doppler spectrophotometry system. Results: Superficial tendon oxygen saturation dropped significantly from 35.9 ± 21 arbitrary units (AU) to 13.5 ± 15, 15.9 ± 16, and 11.1 ± 11 AU (P = .0001) during each period of cryo-compression, respectively. There was significant increase during the recovery period (55.4 ± 29, 65.2 ± 26, and 65.7 ± 27 AU; P = .003), up to +83% of the baseline level. At 8-mm tendon depth, cryo-compression preserved local oxygen with -4% (P = .001) of the baseline level and small but significant increased oxygen saturation of up to +13% (P = .0001). Relative postcapillary venous tendon filling pressures were favorably reduced both superficially (57% ± 34%, 67% ± 27%, and 64% ± 38%, respectively; P = .0004) and deep (76% ± 13%, 79% ± 11%, and 78% ± 18%, respectively; P = .0002). Superficial capillary blood flow was reduced from 48.4 ± 48 to 5 ± 7, 4 ± 5, and 3 ± 4 AU at each period, respectively (-94%, P = .0003), with increased flow during recovery periods of up to 58 ± 64, 58 ± 79, and 47 ± 71 AU, respectively (+20%, P = .265). Deep flow was reduced from 197 ± 147 to 66.7 ± 64, 55 ± 46, and 43 ± 39 AU, respectively (-78%, P = .0002) without increase during recovery periods. Conclusion: Cryo/Cuff exerts beneficial effects on the microcirculatory level of the midportion Achilles tendon with decreased capillary blood flow, preserved deep tendon oxygen saturation, and facilitated venous capillary outflow. [ABSTRACT FROM AUTHOR]

Copyright of Operative Orthopädie und Traumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Neovascularisation can be detected qualitatively by Power Doppler in Achilles tendinopathy. Quantitative data regarding tendon microcirculation have not been established and may be substantial. Purpose: To assess the microcirculation of the Achilles tendon and the paratendon in healthy volunteers as well as in athletes with either midportion or insertional tendinopathy. Study Design: Cohort study; Level of evidence, 2. Methods: In 66 physically active volunteers, parameters of Achilles tendon and paratendon microcirculation, such as tissue oxygen saturation, relative postcapillary venous filling pressures, and microcirculatory blood flow, were determined at rest at 2-mm and 8-mm tissue depths. Forty-one patients never had Achilles pain (25 men, 27 ± 8 years), 14 patients had insertional pain (7 men, 29 ± 8 years), and 11 patients had midportion tendinopathy (7 men, 38 ± 13 years, not significant). Results: Achilles tendon diameter 2 cm and 6 cm proximal to the insertion was increased in symptomatic tendons. Compared with the uninvolved opposite tendon, deep microcirculatory blood flow was significantly elevated at insertional (160 ± 79 vs 132 ± 42, P < .05) as well as in midportion tendinopathy (150 ± 74 vs 119 ± 34, P < .05). The microcirculation in the uninvolved opposite tendon and the normal athlete controls were not significantly different from each other (132 ± 42 insertional asymptomatic vs 119 ± 34 mid-portion vs 120 ± 48 healthy tendon). Insertional paratendon deep microcirculatory flow was elevated in all groups, whereas tissue oxygen saturation and relative postcapillary venous filling pressures were not significantly different. Conclusion: Microcirculatory blood flow is significantly elevated at the point of pain in insertional and midportion tendinopathy. Postcapillary venous filling pressures are increased at both the midportion Achilles tendon and the midportion paratendon, whereas tissue oxygen saturation is not different among the studied groups. We found no evidence of an abnormal microcirculation of the asymptomatic limb in Achilles tendinopathy. [ABSTRACT FROM AUTHOR]

Objectives: AVE0118 is a novel blocker of the K+ channels Kv1.5 and Kv4.3 which are the molecular basis for the human cardiac ultrarapid delayed rectifier potassium current (IKur) and the transient outward current (Ito). The objective of this study was to investigate the effect of AVE0118 on atrial refractoriness (ERP), left atrial vulnerability (LAV) and on left atrial monophasic action potentials (MAP) in pentobarbital anesthetized pigs in comparison to the selective IKr blocker dofetilide in order to assess the therapeutic potential of the novel K+ channel blocker for atrial fibrillation. Methods: Atrial ERP was determined with the S1–S2-stimulus method in the free walls of left and right atrium at 240, 300 and 400 ms basic cycle length (BCL). The inducibility of mostly nonsustained atrial tachyarrhythmias by the premature S2 extrastimulus, which is very high in the left pig atrium and referred to as LAV, was evaluated before and after drugs. Left atrial epicardial MAP was recorded to study the influence of the potassium channel blockers on the time course of repolarization. Left ventricular epicardial MAP, ERP and QT interval were measured to investigate a possible effect of AVE0118 on ventricular repolarization. Results: ERPs determined at 240, 300 and 400 ms BCL were significantly shorter in the left vs. right atrium (99±3, 106±4 and 113±3 ms vs. 133±4 ms, 142±4 and 149±5, respectively; p<0.001; n=21). AVE0118 administered i.v. dose-dependently prolonged the atrial ERP independent from rate and inhibited LAV (100% at 0.5 and 1 mg/kg) while having no effect at all on the corrected QT (QTc) interval. At 1 mg/kg (n=5) AVE0118 prolonged left vs. right atrial ERP by 49.6±4.1 ms vs. 37.7±9.7 ms (means±SEM of changes at 240, 300, and 400 ms BCL), respectively, corresponding to a relative increase of 53.2±6.2% vs. 27.6±6.8% (p<0.05 for percent increase of left vs. right atrial ERP). In a separate group of pigs (n=5) AVE0118 had no effect on left ventricular ERP at 333, 400 and 500 ms BCL and no effect on MAP duration and QT at 600 ms BCL. After 1 mg/kg of AVE0118 the atrial MAP was significantly prolonged already at 10% repolarization (P<0.05; n=7) reaching the maximum at 40% repolarization. In contrast to AVE0118 the effect of dofetilide (10 μg/kg) on atrial MAP started to become significant only at 60% repolarization (n=6) with a maximum increase at 90%. Dofetilide, which prolonged the QTc interval by 16.9% (P<0.001), had a significantly stronger effect on right (34.7±5 ms) vs. left atrial ERP (23.5±7 ms) at 300 ms BCL, respectively, but did not significantly inhibit LAV (14%; n=6). Conclusion: The novel K+ channel blocker AVE0118 prolonged atrial ERP and showed strong atrial antiarrhythmic efficacy with no apparent effect on ventricular repolarization in pigs in vivo. [Copyright &y& Elsevier]

Inhibition of the cardiac Kv1.5 channel, the molecular base for the human cardiac ultrarapid delayed rectifier potassium current (IKur), is considered a new promising atrial selective antiarrhythmic concept since this channel is presumed to contribute to atrial but not ventricular repolarization in the human heart. In a previous study in pigs we found clear baseline differences in refractoriness between left and right atrium with shorter effective refractory periods (ERPs) of the left atrium associated with a high left atrial vulnerability for tachyarrhythmias. In this newly established model we compared atrial and ventricular effects of two novel IKur blockers, S9947 and S20951, with the IKr blockers dofetilide, azimilide, ibutilide and d,l-sotalol. In pentobarbital anesthetized pigs (n=45) we determined ERPs in the free walls of both atria with the S1-S2-stimulus method at three basic cycle lengths (BCL 240/300/400 ms) and QTc-intervals. The incidence of atrial tachyarrhythmias triggered by the S2-extrastimulus of the left atrium was evaluated (referred to as left atrial vulnerability). In contrast to IKr blockade, IKur blockade had no effect on the QT-interval, but prolonged the atrial ERP. The IKur blockers were significantly stronger on left atrial ERP, IKr blockers on right atrial ERP (P<0.05 for all compounds tested). At 240 ms BCL the IKur blocker S20951, 3 mg/kg, prolonged left vs. right atrial ERP by 28±5 ms vs. 12±3 ms and S9947, 3 mg/kg, by 45±7 ms vs. 19±6 ms. By contrast the effect of dofetilide, 10 µg/kg, was stronger on the right than left atrium (47±6 ms vs. 25±2 ms), a profile also found with azimilide (5 mg/kg, 43±3 ms vs. 17±3 ms), ibutilide (15 µg/kg, 70±10 ms vs. 29±4 ms) and d,l-sotalol (1.5 mg/kg, 57±6 ms vs. 36±4 ms). The IKur blockers, S20951and S9947, significantly decreased left atrial vulnerability (–82% and –100%, respectively, P<0.01) in contrast to the selective IKr blocker dofetilide (–14%; n.s.). In conclusion, IKur and IKr blockers showed substantial differences in their atrial and ventricular actions in pigs. IKr blockers were stronger on right atrial ERP, IKur blockers on left atrial ERP, suggesting interatrial differences in the expression of potassium channels. In contrast to selective IKr blockade, IKur blockade inhibited left atrial vulnerability and had no effect on the QT-interval. Thus, blockade of IKur seems to be a promising atrial selective antiarrhythmic concept. [ABSTRACT FROM AUTHOR]

Objectives: Antiarrhythmic drugs have been shown to prolong right atrial refractoriness while data on the left atrium are not available. In pigs we have observed shorter effective refractory periods (ERP) of the left compared with the right atrium associated with a much higher left atrial vulnerability for tachyarrhythmias. Since this could suggest a different distribution of repolarizing ion channels in left and right atrium, we investigated whether antiarrhythmic drugs blocking different ion channels have a differential effect on left and right atrial ERP and left atrial vulnerability. Methods: In pentobarbital-anesthetized pigs (n=40) we measured and compared ERPs in both atria before and after different drugs with the S1-S2 extrastimulus method at three basic cycle lengths (BCL) and assessed the inducibility of atrial fibrillation/flutter (AF/AFL) by the premature S2 stimulus. Results: At the three BCL tested (240/300/400 ms) baseline ERPs were shorter in left vs. right atrium (112±2/124±2/129±2 ms vs. 147±2/163±2/167±2 ms, P<0.001). Mostly non-sustained AF/AFL induced by the S2 extrastimulus was very frequent in the left (68%) and nearly absent in the right atrium (3%). Only amiodarone, 5 mg/kg i.v., which showed a balanced increase of left and right atrial ERP (29±5/33±4/35±3% vs. 30±5/35±5/42±7%), decreased the inducibility of AF/AFL significantly (–72%, P<0.01). Dofetilide, 10 µg/kg i.v., had a stronger effect on right than left atrial ERP (36±4/39±5/46±10% vs. 23±2/22±7/22±5%, P<0.05), while flecainide, 1 mg/kg i.v., prolonged left more than right atrial ERP (58±15/36±7/40±7% vs. 26±5/24±5/21±4%, P<0.05) similar to 1 mg/kg of propafenone (46±5/45±7/32±10% vs. 17±4/21±5/25±8%, P<0.05). Conclusion: The shorter refractoriness of the left compared with the right atrium observed in pigs was associated with a high left atrial vulnerability for tachyarrhythmias, which was reduced only by amiodarone showing a balanced increase of left and right atrial ERP. Dofetilide was stronger on right atrial ERP, flecainide and propafenone on left atrial ERP. These differences suggest a differential distribution of repolarizing ion channels between left and right atrium with possible relevance for the antiarrhythmic efficacy of drugs. [ABSTRACT FROM AUTHOR]