[Growth modulation through hemiepiphysiodesis : Novel surgical techniques: risks and progress]. / Kniegelenksnahe Wachstumsmodulation durch Hemiepiphysiodese : Neue Operationstechniken: Fortschritte und Risiken.

The correction of angular deformities of the lower limb is a key task in paediatric orthopaedic surgery. The growth potential of the physis can be employed for the correction of these malalignments in childhood and adolescence. Hemiepiphysiodesis (HED) is a surgical technique used for growth modulation by permanent or temporary asymmetrical arrest of the growth plate. In permanent HED, exact timing of the procedure is mandatory to achieve optimal correction. Temporary HED through tension band devices such as two-hole-plates or flexible staples has been established as the treatment of choice for growth guidance with excellent results. Implant-associated complications have been significantly reduced through implant modifications. Several experimental procedures have the potential to achieve growth modulation even without the requirement of surgical intervention.

[Laboratory tests for kidney disease]. / Labordiagnostik zum Nachweis einer Nierenerkrankung.

Kidney diseases are among the most frequently reported diseases with a poor prognosis that are diagnosed too late. According to current Kidney Disease Improving Global Outcomes (KDIGO) guidelines, diagnosis and risk stratification are mainly based on functional markers (creatinine and cystatin C), which are used to determine the estimated glomerular filtration rate (eGFR) and the analysis of urinary albumin excretion as a marker of kidney damage. These methods have limitations that can complicate the interpretation of the results and can lead to a delay of the diagnosis as well as to a misinterpretation of the prognosis. Therefore, new damage markers are required that sensitively and specifically detect kidney damage and enable targeted treatment. Urinalysis complements the laboratory diagnostic spectrum of diseases of the kidneys and urinary tract. It is mainly used for screening and provides important information on localization (renal/postrenal) and differentiation of kidney diseases (glomerular/tubulointerstitial).

Copeptin and insulin resistance: effect modification by age and 11 ß-HSD2 activity in a population-based study.

PURPOSE: Arginine vasopressin (AVP) may be involved in metabolic syndrome (MetS) by altering liver glycogenolysis, insulin and glucagon secretion, and pituitary ACTH release. Moreover, AVP stimulates the expression of 11ß-hydroxysteroid-dehydrogenase-type 2 (11ß-HSD2) in mineralocorticosteroid cells. We explored whether apparent 11ß-HSD2 activity, estimated using urinary cortisol-to-cortisone ratio, modulates the association between plasma copeptin, as AVP surrogate, and insulin resistance/MetS in the general adult population. METHODS: This was a multicentric, family-based, cross-sectional sample of 1089 subjects, aged 18-90 years, 47% men, 13.4% MetS, in Switzerland. Mixed multivariable linear and logistic regression models were built to investigate the association of insulin resistance (HOMA-IR)/fasting glucose and MetS/Type 2 Diabetes with copeptin, while considering potential confounders or effect modifiers into account. Stratified results by age and 11ß-HSD2 activity were presented as appropriate. RESULTS: Plasma copeptin was higher in men [median 5.2, IQR (3.7-7.8) pmol/L] than in women [median 3.0, IQR (2.2-4.3) pmol/L], P < 0.0001. HOMA-IR was positively associated with copeptin after full adjustment if 11ß-HSD2 activity was high [ß (95% CI) = 0.32 (0.17-0.46), P < 0.001] or if age was high [ß (95% CI) = 0.34 (0.20-0.48), P < 0.001], but not if either 11ß-HSD2 activity or age was low. There was a positive association of type 2 diabetes with copeptin [OR (95% CI) = 2.07 (1.10-3.89), P = 0.024), but not for MetS (OR (95% CI) = 1.12 (0.74-1.69), P = 0.605), after full adjustment. CONCLUSIONS: Our data suggest that age and apparent 11ß-HSD2 activity modulate the association of copeptin with insulin resistance at the population level but not MeTS or diabetes. Further research is needed to corroborate these results and to understand the mechanisms underlying these findings.

[Application of motorized intramedullary lengthening nails in skeletally immature patients : Indications and limitations]. / Anwendung motorisierter Verlängerungsmarknägel am wachsenden Skelett : Indikationsspektrum und Limitationen.

BACKGROUND: Limb lengthening and deformity correction with motorized intramedullary lengthening nails is a more comfortable and equally safe procedure than the use of external fixators. While this treatment is a well-established method in adults, intramedullary nailing for skeletally immature patients remains a challenge and is the focus of current clinical investigations. OBJECTIVE: Elucidation of the indications for the application of femoral and tibial lengthening nails in skeletally immature patients, presentation of essential characteristics and limitations of the treatment. MATERIAL AND METHODS: Treatment of skeletally immature patients up to 16 years old who had a lengthening nail inserted was retrospectively clinically and radiologically evaluated (2016-2018). RESULTS: A total of 60 procedures were performed on 54 patients. Mean age at the time of surgery was 13.6 years and the mean follow-up time was 10 months. Different nailing approaches were used: antegrade femoral (n = 42), retrograde femoral (n = 10) and antegrade tibial (n = 8). The average amount of lengthening was 45 mm. In 58 of the 60 cases (96.7%) the desired amount of lengthening was achieved, while 2 patients experienced complications that required interruption of the treatment. None of the patients developed growth disorders associated with the nailing approach. CONCLUSION: Different approaches for intramedullary lengthening nails can be used in children and adolescents to correct leg length discrepancy with or without concomitant deformities. The treatment is limited by the size of the available nails, the residual growth and extent of the deformity. Larger trials will be needed to further validate the application of lengthening nails in skeletally immature patients.

[Assessment of kidney function : Creatinine is not the whole story]. / Beurteilung der Nierenfunktion : Kreatinin ist nicht alles.

Chronic renal insufficiency has a high prevalence and leads not only to a severe impairment in the quality of life but also to a higher mortality, mainly due to cardiovascular complications; however, in the early stages where there is still a chance for a therapeutic intervention, it is often underestimated because depending on endogenous factors (e.g. age and muscle mass), serum creatinine could falsely remain in the normal range while kidney function is already impaired. An exact measurement of the glomerular filtration rate (GFR) using radionuclide techniques is cumbersome and usually confined to rare cases, such as in clinical studies. Creatinine clearance measurement by 24-h urine collection requires good patient instructions and is error prone, thus it is limited to special circumstances. In routine clinical practice, estimation of the GFR by calculation algorithms provides the best approach. In recent years the chronic kidney disease epidemiology collaboration (CKD-EPI) formula has become established as the most accurate method. This should be used for screening and continuous surveillance. In addition, urinalysis including dipstick tests and urinary microscopy represent non-invasive, technically simple and economic screening tools. Due to its semiquantitative nature, the results of urinalysis should only to be interpreted after comprehensive consideration of the diagnostic and technical limitations, which are reviewed in this article.

Tolerance of activated pathogenic CD4+ T cells by transcriptional targeting of dendritic cells.

We have recently shown that targeted expression of myelin oligodendrocyte glycoprotein (MOG) to dendritic cells with self-inactivating-lentivirus vectors induces antigen-specific tolerance in naive antigen-specific CD4+ T cells and protects mice from experimental autoimmune encephalomyelitis (EAE). In the present study, we demonstrate that this approach also induces tolerance of activated antigen-specific CD4+ T cells and completely protects mice from passive EAE induction. Tolerance induction did not correlate with the depletion of the preactivated antigen-specific CD4+ T cells. However, upon isolation and in vitro re-stimulation at day 6 after adoptive transfer the MOG-specific CD4+ T cells from the non-tolerized mice produced large amounts of inflammatory cytokines, whereas those from tolerized mice did not. This unresponsiveness correlated with the upregulation of regulatory molecules associated with anergy and regulatory T cells (Tregs). The in vivo depletion of Tregs resulted in EAE susceptibility of the tolerized animals, suggesting that these cells have indeed a role in tolerance induction/maintenance.

[Guided growth in children and adolescents. Correction of leg length discrepancies and leg axis deformities]. / Wachstumslenkung bei Kindern und Jugendlichen. Korrektur von Beinlängendifferenzen und Beinachsendeformitäten.

The treatment of crooked legs and unequal leg length is one of the key tasks of orthopedic surgery. While mature patients usually require complex and invasive surgical interventions, the growth potential of the physes can be used to advantage for correction of these leg length discrepancies and axis deformities of the legs in growing children and adolescents. This guided growth is induced by temporary or permanent and partial or complete arrest of the growth plate, depending on the indications. This technique is called epiphysiodesis. Although these procedures are principally less invasive with few complications, accurate preoperative indications and planning, precise surgical techniques and careful postoperative follow-up examinations are mandatory prerequisites to achieve the desired therapeutic target.

[Special topics in pediatric orthopedics: options and limits of growth guidance]. / Spezielle Themen der Kinderorthopädie : Möglichkeiten und Grenzen der Wachstumslenkung.

BACKGROUND: A main task of pediatric orthopedics is the treatment of legs of different lengths or misshapen legs. Whereas for adult patients complicated and invasive operative interventions are necessary, the growth potential of the epiphysial plate can be utilized in childhood and adolescence to correct leg length differences and leg axis deformities. THERAPY: Epiphysiodesis leads to a guidance of growth via a temporary or permanent and partial or complete blockade of the epiphysial plate depending on the indications. This method is principally a less invasive procedure with few complications. CONCLUSION: Careful preoperative assessment of the indications and planning, precise operative technique and attentive postoperative control investigations are absolutely essential for successful treatment.

[Pigtail suture stent: decisive progress towards double-pigtail stent tolerance and unexpected properties of the suture in the ureter]. / Sondes JFil et MiniJFil: progrès décisifs dans la tolérance des sondes urétérales et propriétés inattendues du fil urétéral.

OBJECTIVE: Double-pigtail stent intolerance reduces the quality of life of patients. By decreasing the amount of material within the bladder, it should be possible to attenuate the symptoms linked to the stent. We evaluated the tolerance of a new stent with a dedicated questionnaire. PATIENTS ET METHODS: The major innovation of the pigtail suture stent (PSS and MiniPSS) was in the replacement of the lower part of the double-pigtail stent with a 0.3 F suture. One hundred and eight patients agreed to be fitted with a PSS. The double-pigtail stents of 24 patients complaining strongly of symptoms were replaced with PSS (group 1) and sixty-eight other patients were fitted directly with the PSS after an endoscopic intervention on the ureter (groups 2 and 3). Sixteen patients with non-obstructive kidney stone received MiniPSS (group 4). RESULTS: Completed questionnaires were obtained from 94 patients. In group 1, the replacement of the double-pigtail stent with a PSS significantly decreased urinary symptom scores (34.4±9.0 vs 20.3±7.4, P<0.0000007), and pain scores (10.1±5.1 vs 4.8±3.2, P=0.0001). The scores of the two first groups fitted with a PSS were similar. Following PSS or MiniPSS implantation, a clear dilation of the ureteral meatus was probably induced by the sutures, facilitating the introduction of an ureteroscope or a flexible ureteroscope sheath (12 F). Following extracorporeal shockwave lithotripsy, the stone fragments gradually slid down the PSS sutures, without renal colic. CONCLUSION: The PSS seems to improve the tolerance of ureteral stent. Unexpectedly, following PSS implantation, we observe a clear dilation of the ureter. We believe that use of a double-pigtail stent should no longer be considered the only way to drain the ureter. Instead, the form of the stent should depend on the patient's disease. LEVEL OF EVIDENCE: 5.

Distribution of regional lung function in upright healthy subjects determined by electrical impedance tomography in two chest examination planes.

Objective. The variation in pulmonary gas content induced by ventilation is not uniformly distributed in the lungs. The aim of our study was to characterize the differences in spatial distribution of ventilation in two transverse sections of the chest using electrical impedance tomography (EIT).Approach. Twenty adult never-smokers, 10 women and 10 men (mean age ± SD, 31 ± 9 years), were examined in a sitting position with the EIT electrodes placed consecutively in a caudal (6th intercostal space) and a cranial (4th intercostal space) chest location. EIT data were acquired during quiet breathing, slow and forced full expiration manoeuvres. Impedance variations representing tidal volume (VT), vital capacity (VC), forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were calculated at the level of individual image pixels and their spatial distribution was determined using the following EIT measures: the centres of ventilation in ventrodorsal (CoVvd) and right-to-left direction (CoVrl), the dorsal and right fractions of ventilation, the coefficient of variation (CV) and the global inhomogeneity (GI) index.Main results. The sums of pixel ventilation-related impedance variations reproduced reliably the volumetric dissimilarities amongVT, VC, FEV1and FVC, with no significant differences noted between the two examination planes. Significant differences in ventilation distribution were found between the planes during tidal breathing and slow full expiration, mainly regarding the ventrodorsal direction, with higher values of CoVvdand dorsal fraction of ventilation in the caudal plane (p< 0.01). No significant differences in the spatial distribution of FEV1and FVC were detected between the examination planes.Significance. The spatial distribution of ventilation differed between the two examination planes only during the relaxed (quiet breathing and slow VC manoeuvre) but not during the forced ventilation. This effect is attributable to the differences in thoracoabdominal mechanics between these types of ventilation.

Percutaneous CT-guided radio-frequency ablation of osteoid osteoma of the foot and ankle.

INTRODUCTION: Percutaneous radiofrequency ablation (RFA) has been considered, in recent years, the standard treatment for osteoid osteoma (OO) of the appendicular skeleton. The variable clinical presentations in the foot and ankle pose problems in diagnosis, localization and thus treatment. The aim of this study was to assess the efficacy of RFA for patients with osteoid osteoma of the foot and ankle. MATERIALS AND METHODS: A total of 29 patients (22 males, 7 females; mean age 16.7 years; range 8-44 years) with OO of the foot and ankle (distal tibia, n = 17; distal fibula, n = 6; talus, n = 3; calcaneus, n = 3) were enrolled in the study. A CT-guided RFA was performed, using a cool-tip electrode without the cooling system, heating the lesion up to 90 °C for 4-5 min. Clinical success, assessed at a minimum follow-up of 1 year, was defined as complete or partial pain relief after RFA. Pain and clinical outcomes were scored pre-operatively and at the follow-up with a visual analogue scale (VAS) and with the American Orthopaedic Foot and Ankle Society (AOFAS) score. Complications and local recurrences were also recorded. RESULTS: Clinical success was achieved in 26 patients (89.6 %). After RFA, mean VAS and AOFAS score significantly improved from 8 ± 1 to 2 ± 1 (p < 0.05) and from 60.7 ± 12.7 to 89.6 ± 7.1 (p < 0.05), respectively. Two patients experienced partial relief of pain and underwent a second successful ablation. Local recurrences were found in three patients, always associated with pain. These underwent conventional excision through open surgery. No early or late complications were detected after RFA. CONCLUSION: CT-guided RFA of foot and ankle osteoid osteoma is a safe and effective procedure, showing similar results for the rest of the appendicular skeleton.

[Determination of skeletal age : comparison of the methods of Greulich and Pyle and Tanner and Whitehouse]. / Bestimmung des Skelettalters : Vergleich der Methoden nach Greulich und Pyle sowie Tanner und Whitehouse.

PURPOSE: The main purpose of this study was to evaluate the accuracy and the time required to determine skeletal age (SA) in healthy children by the methods of Greulich and Pyle (GP) and of Tanner and Whitehouse (TW). Based on these results recommendations for routine clinical practice is to be established. MATERIALS AND METHODS: In this study a total of 63 children between the ages of 5 and 18 years were included. Each conventional radiographic image of the left hand was assessed under blinded conditions by 5 or 6 examiners and the time needed was recorded. The assessments were repeated after 2 months. RESULTS: The average chronological age was estimated slightly too low by the GP method and clearly too high by TW. The mean deviation between the results of two examiners tended to be higher with the TW method than with GP. Repeated assessments of SA by the same examiner deviated only slightly for both methods. The time taken to assess the SA by GP was less than half as long as for TW. An improvement in accuracy of SA estimation after repeated use was only observed for GP. CONCLUSION: Of the two methods tested neither proved to be superior. Determination of SA by the GP method was found to be more suitable for routine clinical practice.

[What reasonable applications for regional citrate anticoagulation in renal replacement therapy?]. / Quelles applications raisonnables pour l'anticoagulation régionale au citrate en épuration extrarénale?

Regional citrate anticoagulation of the extracorporeal circuits (CRA) experienced considerable growth over the past decade. This development is partly explained by the significant progresses made in the field of bioengineering. These allow a secure administration of citrate, while an increasing availability of ionized calcium measurement at the bedside allows reactivity in monitoring the treatment. An increasing severity of the medical condition of patients requiring blood purification treatment gives more contrast to the profile of patient who may benefit from a CRA. If some methods of renal replacement therapy are well suited to this mode of anticoagulation, others are, to date, only at the stage of development and are applied under close medical supervision.

[New radiological techniques to investigate patients suffering from chronic kidney disease]. / Nouvelles techniques radiologiques pour les patients insuffisants rénaux.

Radiological investigations using gadolinium or intravenous iodinated contrast products are used cautiously in patients suffering from chronic kidney disease because of their risk of acute kidney injury and systemic nephrogenic fibrosis. In this article, we review several radiological alternatives that can be useful to obtain renal anatomical and/or functional information in this patient population. The basic principles, indications, and advantages and limitations of Doppler ultrasound with measurement of the resistance index, contrast-enhanced ultrasound, and a technique called BOLD-MRI (blood-oxygenation level dependent-MRI) are discussed.

Regional lung function measures determined by electrical impedance tomography during repetitive ventilation manoeuvres in patients with COPD.

OBJECTIVE: Current standards for conducting spirometry examinations recommend that the ventilation manoeuvres needed in pulmonary function testing are carried out repeatedly during sessions. Chest electrical impedance tomography (EIT) can determine the presence of ventilation heterogeneity during such manoeuvres, which increases the information content derived from such examinations. The aim of this study was to characterise regional lung function in patients with chronic obstructive pulmonary disease (COPD) during repetitive forced full ventilation manoeuvres. Regional lung function measures derived from these manoeuvres were compared with quiet tidal breathing. APPROACH: Sixty hospitalised patients were examined during up to three repeated ventilation manoeuvres. Acceptable spirometry manoeuvres were performed and EIT recordings suitable for analysis obtained in 53 patients (12 women, 41 men; age: 68 ± 12 years (mean ± SD)). Pixel values of tidal volume, forced full inspiratory and expiratory volume in 1 s, and forced inspiratory and expiratory vital capacity were calculated from the EIT data. Spatial ventilation heterogeneity was assessed using the coefficient of variation, global inhomogeneity index, and centres and regional fractions of ventilation. Temporal inhomogeneity was determined by examining the pixel expiration times needed to exhale 50% and 75% of regional forced vital capacity. MAIN RESULTS: All EIT-derived measures of regional lung function showed reproducible results during repetitive examinations. Parameters of spatial heterogeneity obtained from quiet tidal breathing were comparable with the measures derived from the forced manoeuvres. SIGNIFICANCE: Measures of spatial and temporal ventilation heterogeneity obtained in COPD patients by EIT provide comparable findings during repeated examinations within one testing session. Quiet tidal breathing generates similar information on ventilation heterogeneity as forced manoeuvres that demand a high amount of patient effort.

Fibula-Assisted Segment Transport (FAST) for Defect Reconstruction after Resection of Tibial Adamantinoma: Report of Two Treatments.

Intramedullary limb lengthening via lengthening nails has been performed for more than three decades to overcome leg length inequalities. Plate-assisted bone segment transport (PABST) has recently been described for the reconstruction of segmental bone defects. We modified this procedure by using the ipsilateral fibula as a "biological plate" and report on its technical particularities and application in the reconstructive treatment of adamantinomas of the tibia in two patients. Both patients were successfully treated by wide resection and reconstruction of the tibial bone via bone segment transport through an expandable intramedullary nail using the remaining ipsilateral fibula to provide stabilization and guidance. This procedure was titled "fibula-assisted segment transport" (FAST). This is a new and promising technique that allows an entirely biological reconstruction of large bone defects of the tibia.

Identification and analysis of stable breathing periods in electrical impedance tomography recordings.

Objective. In this paper, an automated stable tidal breathing period (STBP) identification method based on processing electrical impedance tomography (EIT) waveforms is proposed and the possibility of detecting and identifying such periods using EIT waveforms is analyzed. In wearable chest EIT, patients breathe spontaneously, and therefore, their breathing pattern might not be stable. Since most of the EIT feature extraction methods are applied to STBPs, this renders their automatic identification of central importance.Approach. The EIT frame sequence is reconstructed from the raw EIT recordings and the raw global impedance waveform (GIW) is computed. Next, the respiratory component of the raw GIW is extracted and processed for the automatic respiratory cycle (breath) extraction and their subsequent grouping into STBPs.Main results. We suggest three criteria for the identification of STBPs, namely, the coefficient of variation of (i) breath tidal volume, (ii) breath duration and (iii) end-expiratory impedance. The total number of true STBPs identified by the proposed method was 294 out of 318 identified by the expert corresponding to accuracy over 90%. Specific activities such as speaking, eating and arm elevation are identified as sources of false positives and their discrimination is discussed.Significance. Simple and computationally efficient STBP detection and identification is a highly desirable component in the EIT processing pipeline. Our study implies that it is feasible, however, the determination of its limits is necessary in order to consider the implementation of more advanced and computationally demanding approaches such as deep learning and fusion with data from other wearable sensors such as accelerometers and microphones.

Elastic constants and dimensions of imprinted polymeric nanolines determined from Brillouin light scattering.

Elastic constants and cross-sectional dimensions of imprinted nanolines of poly(methyl methacrylate) (PMMA) on silicon substrates are determined nondestructively from finite-element inversion analysis of dispersion curves of hypersonic acoustic modes of these nanolines measured with Brillouin light scattering. The results for the cross-sectional dimensions, under the simplifying assumption of vertical sides and a semicircular top, are found to be consistent with dimensions determined from critical-dimension small-angle x-ray scattering measurements. The elastic constants C(11) and C(44) are found to be, respectively, 11.6% and 3.1% lower than their corresponding values for bulk PMMA. This result is consistent with the dimensional dependence of the quasi-static Young's modulus determined from buckling measurements on PMMA films with lower molecular weights. This study provides the first evidence of size-dependent effects on hypersonic elastic properties of polymers.

Thalamic and cortical afferents differentiate anterior from posterior cingulate cortex in the monkey.

The anterior cingulate cortex receives thalamic afferents mainly from the midline and intralaminar nuclei rather than the anterior thalamic nuclei. In contrast, the posterior cingulate cortex receives afferents primarily from the anterior thalamic nuclei and from extensive cortical areas in the frontal, parietal, and temporal lobes. These contrasting afferents may provide a structural basis for pain-related functions of the anterior cingulate cortex.