Long-term outcomes of muscle volume and Achilles tendon length after Achilles tendon ruptures

Purpose: The best treatment for Achilles tendon (AT) ruptures remains controversial. Long-term follow-up with radiological and clinical measurements is needed. Methods: In this retrospective multicentre cohort study, patients (n=52) were assessed at a mean of 91months follow-up after unilateral AT rupture treated by open, percutaneous or conservative (non-surgical) treatment. Demographic parameters, time off work, maximum calf circumference and clinical scores (ATRS, Hannover, AOFAS) were evaluated. Muscle volume and cross-sectional area of the calf and AT length were measured on MR images and were compared between groups and to each patient's healthy contralateral leg. Results: Reduced muscle volume was found across all groups with a higher muscle volume in the conservative (729.9±130.3cm3) compared to the percutaneous group (675.9±207.4cm3, p=0.04). AT length was longer in the affected leg (198.4±24.1 vs. 180.6±25.0mm, p<0.0001) without difference in subgroup analysis. Clinically measured ankle dorsiflexion showed poor correlation with AT length (R 2=0.07, p=0.008). Muscle volume strongly correlated with the cross-sectional area (R 2=0.6, p<0.0001) but showed a weak correlation with the Hannover score (R 2=0.08, p=0.048). Maximum calf circumference correlated with muscle volume (R 2=0.42, p<0.0001). Conclusions: No significant difference between the treatment groups was found in muscle volume, AT length, clinical measures or days off work. Cross-sectional area and maximum calf circumference are cost-effective measurements and a good approximation of muscle volume and can thus be used in a clinical setting while clinical dorsiflexion should not be used. Level of evidence: II

Septaly Oriented Mild Aortic Regurgitant Jets Negatively Influence Left Ventricular Blood Flow—Insights From 4D Flow MRI Animal Study

Objectives: Paravalvular leakage (PVL) and eccentric aortic regurgitation remain a major clinical concern in patients receiving transcatheter aortic valve replacement (TAVR), and regurgitant volume remains the main readout parameter in clinical assessment. In this work we investigate the effect of jet origin and trajectory of mild aortic regurgitation on left ventricular hemodynamics in a porcine model. Methods: A pig model of mild aortic regurgitation/PVL was established by transcatheter piercing and dilating the non-coronary (NCC) or right coronary cusp (RCC) of the aortic valve close to the valve annulus. The interaction between regurgitant blood and LV hemodynamics was assessed by 4D flow cardiovascular MRI. Results: Six RCC, six NCC, and two control animals were included in the study and with one dropout in the NCC group, the success rate of model creation was 93%. Regurgitant jets originating from NCC were directed along the ventricular side of the anterior mitral leaflet and integrated well into the diastolic vortex forming in the left ventricular outflow tract. However, jets from the RCC were orientated along the septum colliding with flow within the vortex, and progressing down to the apex. As a consequence, the presence as well as the area of the vortex was reduced at the site of impact compared to the NCC group. Impairment of vortex formation was localized to the area of impact and not the entire vortex ring. Blood from the NCC jet was largely ejected during the following systole, whereas ejection of large portion of RCC blood was protracted. Conclusions: Even for mild regurgitation, origin and trajectory of the regurgitant jet does cause a different effect on LV hemodynamics. Septaly oriented jets originating from RCC collide with the diastolic vortex, reduce its size, and reach the apical region of the left ventricle where blood resides extendedly. Hence, RCC jets display hemodynamic features which may have a potential negative impact on the long-term burden to the heart

Pseudomonas Strains Naturally Associated with Potato Plants Produce Volatiles with High Potential for Inhibition of Phytophthora infestans

Bacteria emit volatile organic compounds with a wide range of effects on bacteria, fungi, plants, and animals. The antifungal potential of bacterial volatiles has been investigated with a broad span of phytopathogenic organisms, yet the reaction of oomycetes to these volatile signals is largely unknown. For instance, the response of the late blight-causing agent and most devastating oomycete pathogen worldwide, Phytophthora infestans, to bacterial volatiles has not been assessed so far. In this work, we analyzed this response and compared it to that of selected fungal and bacterial potato pathogens, using newly isolated, potato-associated bacterial strains as volatile emitters. P. infestans was highly susceptible to bacterial volatiles, while fungal and bacterial pathogens were less sensitive. Cyanogenic Pseudomonas strains were the most active, leading to complete growth inhibition, yet noncyanogenic ones also produced antioomycete volatiles. Headspace analysis of the emitted volatiles revealed 1-undecene as a compound produced by strains inducing volatile-mediated P. infestans growth inhibition. Supplying pure 1-undecene to P. infestans significantly reduced mycelial growth, sporangium formation, germination, and zoospore release in a dose-dependent manner. This work demonstrates the high sensitivity of P. infestans to bacterial volatiles and opens new perspectives for sustainable control of this devastating pathogen

Bodenbeurteilung im Feld

Landwirtschaftlich genutzter Boden ist durch das Bearbeiten und Befahren zahlreichen Belastungen ausgesetzt. Nach einer strukturschädigenden Massnahme kann eine vollständige Regeneration des Bodens mehrere Jahre dauern. Die Behebung von Bodenschäden wird in dieser Broschüre nicht behandelt; sie zeigt aber auf, wie Zustand und Belastbarkeit des Bodens mithilfe von Hand-Grabwerkzeuge und den eigenen Sinnen einfach beurteilt werden kann

Long-term biomechanical outcomes after Achilles tendon ruptures

Purpose: The ideal treatment for Achilles tendon ruptures is still unknown. Biomechanical were correlated to radiological and clinical parameters to study outcomes. Methods: In this retrospective, assessor-blinded multi-centre cohort study, 52 patients with unilateral Achilles tendon rupture were assessed, each at least 3years after injury. Patients underwent open surgery, percutaneous surgery or non-surgical treatment of Achilles tendon rupture. Both legs underwent plantar pressure distribution and isokinetic measures. Demographic parameters, maximum calf circumference (MCC) and clinical scores (American Orthopaedic Foot and Ankle Society, Achilles tendon rupture score, Hannover) were also evaluated. Complications were not assessed. Results: Peak plantar flexion torque (PPFT) was significantly weaker on the treated side compared to the untreated leg [80.4±29.7Nm (mean±SD) vs. 92.1±27.4Nm, p<0.0001]. PPFT and push-off force (POFF) were not different between treatment groups nor was there a leg difference in POFF alone. There was only a weak correlation of clinical scores and PPFT or POFF, respectively. MCC correlated significantly with both PPFT (R 2=0.21, p=0.01) and POFF (R 2=0.29, p<0.0001). POFF appeared to be a predictor of PPFT (R 2=0.31, p<0.0001). Open surgery outperformed non-surgical treatment in terms of centre-of-pressure line (p=0.007), torque per muscle volume (p=0.04) and relative POFF per body weight (p=0.02) and relative in side comparison (p=0.03). Conclusions: Clinical scores do not predict biomechanical outcomes. Clinically measured MCC is a good predictor of PPFT and POFF and can easily be used in clinical practice. Relative POFF in side comparison as well as per body weight favours surgical treatment

Konservative Therapie von Sehnenverletzungen

The treatment of tendon injuries in general presents one of the most relevant challenges in sports medicine, and there is high demand to ensure a long-term successful treatment and short time loss of the sport. However, there are only a few contributions providing guidance and recommendations for the nonoperative treatment of tendon injuries. The 2016 GOTS Expert Meeting, initiated by the German-Austrian-Swiss Society for Orthopaedic Traumatologic Sports Medicine (GOTS), focused on the topic of muscle and tendon injuries. The committee was composed of twenty-two medical specialists. Nine of them were delegated to a subcommittee focusing on the nonoperative treatment of tendon injuries. The recommendations and statements that were developed were reviewed by the entire consensus committee and voted on by the members. The committee reached a consensus on the utility and efficacy of the management of tendon injuries. Addressing precipitating risk factors and the concept of load management including well designed training programs are one of the most relevant steps in the treatment of tendinopathies. A wide variety of additional therapeutic approaches can be considered individually based on the underlying localisation, the grade of injury and the healing phase. The present work provides a structured overview on the diverse conservative treatment strategies of tendon injuries and evaluates their efficacy with respect to the existing scientific evidence and clinical expertise in the context of basic science on the healing process of tendon injuries

Septaly Oriented Mild Aortic Regurgitant Jets Negatively Influence Left Ventricular Blood Flow-Insights From 4D Flow MRI Animal Study

Objectives: Paravalvular leakage (PVL) and eccentric aortic regurgitation remain a major clinical concern in patients receiving transcatheter aortic valve replacement (TAVR), and regurgitant volume remains the main readout parameter in clinical assessment. In this work we investigate the effect of jet origin and trajectory of mild aortic regurgitation on left ventricular hemodynamics in a porcine model. Methods: A pig model of mild aortic regurgitation/PVL was established by transcatheter piercing and dilating the non-coronary (NCC) or right coronary cusp (RCC) of the aortic valve close to the valve annulus. The interaction between regurgitant blood and LV hemodynamics was assessed by 4D flow cardiovascular MRI. Results: Six RCC, six NCC, and two control animals were included in the study and with one dropout in the NCC group, the success rate of model creation was 93%. Regurgitant jets originating from NCC were directed along the ventricular side of the anterior mitral leaflet and integrated well into the diastolic vortex forming in the left ventricular outflow tract. However, jets from the RCC were orientated along the septum colliding with flow within the vortex, and progressing down to the apex. As a consequence, the presence as well as the area of the vortex was reduced at the site of impact compared to the NCC group. Impairment of vortex formation was localized to the area of impact and not the entire vortex ring. Blood from the NCC jet was largely ejected during the following systole, whereas ejection of large portion of RCC blood was protracted. Conclusions: Even for mild regurgitation, origin and trajectory of the regurgitant jet does cause a different effect on LV hemodynamics. Septaly oriented jets originating from RCC collide with the diastolic vortex, reduce its size, and reach the apical region of the left ventricle where blood resides extendedly. Hence, RCC jets display hemodynamic features which may have a potential negative impact on the long-term burden to the heart.ISSN:2297-055

Dos and don'ts in large animal models of aortic insufficiency

Aortic insufficiency caused by paravalvular leakage (PVL) is one of the most feared complications following transcatheter aortic valve replacement (TAVI) in patients. Domestic pigs (Sus scrofa domestica) are a popular large animal model to study such conditions and develop novel diagnostic and therapeutic techniques. However, the models based on prosthetic valve implantation are time intensive, costly, and often hamper further hemodynamic measurements such as PV loop and 4D MRI flow by causing implantation-related wall motion abnormalities and degradation of MR image quality. This study describes in detail, the establishment of a minimally invasive porcine model suitable to study the effects of mild-to-moderate “paravalvular“ aortic regurgitation on left ventricular (LV) performance and blood flow patterns, particularly under the influence of altered afterload, preload, inotropic state, and heart rate. Six domestic pigs (Swiss large white, female, 60–70 kg of body weight) were used to establish this model. The defects on the hinge point of aortic leaflets and annulus were created percutaneously by the pierce-and-dilate technique either in the right coronary cusp (RCC) or in the non-coronary cusp (NCC). The hemodynamic changes as well as LV performance were recorded by PV loop measurements, while blood flow patterns were assessed by 4D MRI. LV performance was additionally challenged by pharmaceutically altering cardiac inotropy, chronotropy, and afterload. The presented work aims to elaborate the dos and don'ts in porcine models of aortic insufficiency and intends to steepen the learning curve for researchers planning to use this or similar models by giving valuable insights ranging from animal selection to vascular access choices, placement of PV Loop catheter, improvement of PV loop data acquisition and post-processing and finally the induction of paravalvular regurgitation of the aortic valve by a standardized and reproducible balloon induced defect in a precisely targeted region of the aortic valve.ISSN:2297-176