Morphological alterations in the inner ear of the arylsulfatase A-deficient mouse

Metachromatic leukodystrophy of humans is an inherited sulfatide lipidosis due to deficiency of arylsulfatase A (ASA). As an animal model, ASA(-/-) mice have been generated. A previous study showed that the mice lose most of their spiral (acoustic) ganglion cells and develop deafness by the end of the first year of life. The present report describes the sulfatide histochemistry and ultrastructure of the inner ears of ASA(-/-) mice at 0.5-26 months of age. Lysosomal accumulation of sulfatides was observed in various cell types such as Schwann cells that maintain the myelin sheaths around the spiral and vestibular ganglion cells, periaxonal Schwann cells, macrophages, and spiral and vestibular ganglion cell perikarya. In the spiral ganglion, the only surviving neurons were those which are primarily non-myelinated (type 2 cells). However, the myelinated spiral neurons and their processes were rarely encountered within the process of dying, suggesting that this was a rather rapid process. Since the myelin sheaths around dying perikarya and axons appeared structurally normal, the primary cause of the neuronal cell death seems to reside in the neuron. In contrast to the spiral ganglion, the vestibular ganglion as a whole survived throughout the period of observation. The organ of Corti and the vestibular apparatus appeared preserved at the light microscopic level, despite massive sulfatide storage in the vestibular hair cells.     

Primary stability of unicompartmental knee arthroplasty under dynamic compression-shear loading in human tibiae

BackgroundThe objective of our study was to evaluate the impact of a single- (“implant only”) versus a double-layer (“implant & bone”) cementing technique on the primary stability of unicompartmental tibial plateaus under dynamic compression-shear loading conditions in human tibiae.MethodsTwelve fresh-frozen human knees of a mean donor age of 72.3 years were used to perform medial UKA under a less invasive parapatellar surgical approach. The tibiae were divided into two groups of matched pairs based on comparable trabecular bone mineral density. To assess the primary stability, a new method based on a combination of dynamic compression-shear testing, kinematic analysis of the tibial plateau migration relative to the bone and evaluation of the cement layer by CT-scans and fragments cut through the implant–cement–bone interface in the frontal plane was introduced.FindingsFor the “implant only” cementation technique the mean load to failure was 2600 (SD 675) N and for “implant & bone” it was 2820 (SD 915) N. Between the final load level at failure and the bone mineral density a significant correlation was found for the groups “implant only” (r_s = 0.875) and “implant & bone” (r_s = 0.907).InterpretationFrom our observations, we conclude that there is no significant difference between a single- (“implant only”) and double-layer (“implant & bone”) cementing technique in the effect on the primary stability of unicompartmental tibia plateaus, in terms of failure load, correlation between final load at failure and bone mineral density, migration characteristics, cement layer thickness and penetration depth.     

Hardware Failures in Spinal Cord Stimulation for Failed Back Surgery Syndrome

Spinal cord stimulation (SCS) is an efficient means for treatment of the postsurgical lumbar spine condition known as failed back surgery syndrome (FBSS). Although the devices and the implantation techniques are well established and the technology is sophisticated, there are some complications caused by hardware failures. This study was aimed at identifying the most frequent types of hardware failures and their causes in FBSS patients treated with SCS. In a retrospective analysis, a group of 42 FBSS patients using single lead SCS for 6–74 months was evaluated. Only hardware failures were considered in the analysis, and parameters such as occurrence of failure after primary implantation of the device, frequency and site of failure, stimulation time to failure (TF), and overall time of SCS usage were recorded. In the patient group studied, 12 surgical corrections of the hardware were carried out in 10 patients. In eight patients there was a single corrective procedure, in two additional cases there were two surgically corrected hardware failures each. The most often encountered type of hardware failure was lead breakage or disruption of insulation (percutaneously placed Quad leads only) leading to short circuiting and dysfunction (n= 8). Second in frequency were receiver (model 3470) failures due to insulation leakage at the plug connection site (n= 2). In one case, extension cable breakage caused dysfunction of the system, and another dysfunction was caused by distal extension cable disconnection. In conclusion, SCS is a low‐complication procedure for treatment of benign low‐back pain, but seems to be prone to lead and insulation failures.     

Improvement in the healing of colonic anastomoses by vitamin B5 and C supplements. Experimental study in the rabbit

To study the effects of vitamins B5 and C on the healing process of colonic anastomoses, 3 groups of 20 rabbits were given daily either placebo (group A), or vitamin B5 (100 mg/kg: group B) or vitamin C (100 mg/kg: group C). After 8 days of supplementation, via a midline incision and under general anaesthesia, 2 colonic segments were removed, and the continuity was restored. On the 3rd post-operative day, the rabbits were killed and the anastomoses were removed. Mechanical properties of both normal colon and anastomoses were determined by using bursting pressure tests, number of burst anastomoses, fibroblast count, hydroxyproline concentration and determination by microanalysis of trace element content: Mg, P, S, Ca, Fe, Cu, Zn and Mn. Vitamin B5 (p = 0.03) and vitamin C (p less than 0.01) both decreased the number of burst anastomoses. Furthermore the required bursting pressure values were higher with vitamin C (p = 0.01) than in controls. Both vitamins restored normal Zn levels at the anastomotic site, whereas these levels decreased on the 3rd post-operative day during the normal healing process of colonic anastomosis. Moreover, vitamins B5 and C increased Fe, Cu and Mn levels, which are intimately all involved in collagen synthesis. Vitamins B5 and C enhance the colonic wound healing process in the rabbit, acting together in synergy in vivo as well as in vitro, as previously demonstrated.     

Querosteotomie des Femurs beim Prothesenschaftwechsel als Alternative zum transfemoralen Zugang

Zusammenfassung Operationsziel Wechsel gelockerter Hüftendoprothesenschäfte mit großen proximalen Femurdefekten, die eine distale Verankerung des Revisionsschafts erfordern. Indikationen Sowohl die Entfernung von distalen Zementresten und gebrochenen Prothesenschaftanteilen als auch die Implantation eines Revisionsschafts bei starker Antekurvation des Femurs können sich als problematisch erweisen und eine Femurquerosteotomie erfordern. Kontraindikationen Schwere Atrophie der Femurdiaphyse. Infektion. Schlechter Allgemeinzustand des Patienten. Operationstechnik Entfernung des Primärimplantats. Querosteotomie mindestens 12 cm unterhalb der Spitze des Trochanter major. Entfernung verbliebener Zementreste aus dem proximalen und distalen Femurfragment. Konisches Auffräsen des distalen Femurs. Gegebenenfalls Sicherungscerclagen am distalen Schaft. Revisionsschaftprothese in das proximale Fragment einfädeln und in das distale Fragment einschlagen. Proximale Femurfragment mit kortikospongiösen Chips gegen das Implantat verblocken. Weiterbehandlung Frühe funktionelle Behandlung mit schrittweisem Belastungsaufbau. Ergebnisse Zwölf Patienten (acht Frauen, vier Männer, Durchschnittsalter bei Operationen 70 Jahre und 1 Monat). Durchschnittlicher Nachuntersuchungszeitraum 2 Jahre und 11 Monate (1 Jahr 9 Monate bis 5 Jahre 10 Monate). Durchschnittlicher Harris-Hip-Score 80,2 Punkte. Score nach Merle d'Aubigné: viermal sehr gut, einmal gut, zweimal befriedigend, viermal ausreichend, einmal schlecht. In allen Fällen röntgenologisch ausreichende knöcherne Überbrückung des Osteotomiespalts. Abstract Objective Exchange of a loosened femoral component in the presence of large proximal bone defects which require a distal anchorage of the revision stem. Indications Removal of remaining cement fragments from distal femur. Extraction of broken part(s) of femoral component. Marked anterior bowing of femoral shaft before insertion of revision stem. Contraindications Severe osteopenia of the femoral shaft. Infection. Poor general health. Surgical Technique Removal of femoral component. Transverse femoral osteotomy at least 12 cm distal to the tip of the greater trochanter. Removal of remaining cement from distal and proximal fragments. Conical reaming of distal femur. If necessary, prophylactic wire cerclage of distal fragment. Insertion of revision stem through the proximal fragment and impaction into the distal fragment. Packing of the defect of the proximal fragment with corticocancellous bone grafts to increase stability. Results Assessment of twelve patients (eight women, four men, average age at surgery 70 years and 1 month). Average length of follow-up 2 years and 11 months (1 year, 9 months to 5 years, 10 months). Average Harris hip score 80.2 points. Merle d'Aubigné score: four excellent, one good, two satisfactory, four acceptable, and one poor result. A sufficient bony bridging of the osteotomy gap was seen radiologically in all patients.     

Ex-vivo investigations on endoluminal laser therapy of varicosis – An optimization process

ObjectiveThis study was performed to compare the acute effects of different endoluminal heating procedures, by which obstruction of insufficient veins could be induced in an established standardized experimental ex-vivo model.MethodsThe model consists of the subcutaneous foot vein from recently slaughtered cows. Different energy sources (laser and radiofrequency), application devices and energy application parameters were compared in an iterative optimizing process. Following energy application the vein tissue was harvested and prepared for histology.ResultsBy means of the developed ex-vivo model reproducible conditions for the application of endoluminal thermal energy were enabled in each specimen. Radiofrequency-treated veins showed macroscopic shrinkage, contraction of vessels and induration of tissue. Histologically a circumferential and homogenous thickening of the vessel wall could be described. Dependent on the laser treatment protocol, in-situ dissection of the treated veins showed a broad spectrum of effects. These effects ranged from blood deposits in perivascular tissue and perivascular thermal lesions to transmural coagulated vein tissue inducing obstruction of the lumen.ConclusionThis standardized model is applicable to investigate acute effects of endoluminal treatment protocols. Changes in the protocol could be easily performed and investigated in order to develop optimized treatment protocols. These ex-vivo experiments indicate that endovenous laser treatment should be modified and needs treatment standardization to ensure a controlled homogenous circumferential thermal damage.     

Treatment of Patients with Early Breast Cancer: Evidence,Controversies, Consensus: German Expert Opinions on the 17th International St. Gallen Consensus Conference

This yearʼs 17th St. Gallen (SG) Consensus Conference on the Treatment of Patients with Early Breast Cancer (SG-BCC) with the title “Customizing local and systemic therapies for women with early breast cancer” focused on the challenge of targeting the treatment of early breast cancer more specifically to the individual disease situation of each patient. As in previous years, a German working group of leading breast cancer experts discussed the results of the international SG-BCC 2021 in the context of the German guideline. It is helpful to compare the SG recommendations with the recently updated treatment recommendations of the Breast Commission of the German Working Group on Gynaecological Oncology (Arbeitsgemeinschaft Gynäkologische Onkologie e. V., AGO) and the S3 guideline because the SG-BCC panel comprised experts from different countries, which is why country-specific aspects can be incorporated into the SG recommendations. The German treatment recommendations of the AGO and the S3 guideline are based on current evidence. Nevertheless, any therapeutic decision must always undergo a risk-benefit analysis for the specific situation and to be discussed with the patient.Key words: St. Gallen Consensus 2021, early breast cancer, surgery, radiotherapy, (neo)adjuvant systemic therapy, targeted therapy     

Electrochemical surface reactions of intermediates formed in the oxidative ethanol adsorption on porous Pt and PtRu

The oxidative ethanol adsorption and electrochemical surface reactions of adsorbed intermediates were studied on electrodeposited Pt, Ru, Pt_0.92Ru_0.08 and Pt_0.85Ru_0.15 in 1 M HClO₄. A flow cell procedure was performed in order to separate surface reactions of intermediates formed in the oxidative ethanol adsorption from those reactions for ethanol in the bulk electrolyte solution. Oxidation and reduction reactions of adsorbed species were studied by potential-controlled electrodesorption spectrometry. No adsorbate formation was observed on a pure Ru electrode. In all cases, CO₂ was the sole product formed in the oxidative electrodesorption of the adsorbates. Using ¹²CH₃¹²CH₂OH and ¹²CH₃¹³CH₂OH, the oxidation reaction pathways of each C-atom to CO₂ were followed. On the other hand, methane and ethane were detected during the reductive electrodesorption of adlayer species. The onset potential for these reduction products shifts to more negative potentials as the Ru content of the alloy increases. The methane to ethane yield ratio decreases in the sequence Pt>Pt_0.92Ru_0.08>Pt_0.85Ru_0.15. A critical interpretation of the experimental data leads to a tentative yield of different adsorbed species as function of the Ru surface concentration.