One year after proximal or distal periprosthetic fracture of the femur -two conditions with divergent outcomes?

INTRODUCTION

Arthroplasty of the hip and knee is 1 of the 20 most frequent operations in Germany. Periprosthetic fracture is one of the most feared complications following primary or revision arthroplasty. Present publication aims to analyse differences between patients with periprosthetic fracture around total knee arthroplasty (PFTKA) and patients with periprosthetic fracture around total hip arthroplasty (PFTHA) concerning demographics, clinical course, complications and return to pre-fracture mobility.

METHODS

Prospective single-centre observation study of periprosthetic femoral fractures with stable implants. Present subgroup analysis includes patients with PFTKA and PFTHA. All patients were treated with polyaxial angular stable plates using two standardized techniques: a minimally invasive percutaneous distal insertion technique and a mini-open technique. Data collection included implant- and operation-related information as well as demographics, clinical course, complications and return to pre-fracture mobility. Data were collected during a 12-month follow-up.

RESULTS

We were able to analyse the data of 73 patients. The PFTKA group had 37 patients with a mean age of 76 ± 10 years; 88% were female. After 1 year, 3 patients in this cohort had died; 68% of survivors had reached their pre-fracture mobility; 22% had undergone operative revisions for various reasons. The PFTHA cohort included 36 patients with a mean age of 80 ± 13 years, 72% were female. After 1 year, 9 patients had died in this cohort, 42% of survivors had reached their pre-fracture mobility. Non-operative complications occurred for 16% in the PFTKA group and 64% in the PFTHA group (p < 0.001). 11% had undergone operative revisions for various reasons, among them, two cases of nonunion but no primary infection.

CONCLUSION

On average, compared to the PFTHA patients, PFTKA patients were younger, underwent significantly lower rates of non-operative complications, had a tendency towards lower mortality, and returned to pre-fracture mobility at higher rates, although they tended to have more revisions when compared to treatment for PFTHA. Overall, when periprosthetic fractures of the femur were treated using polyaxial locking plate osteosynthesis, patients showed very low rates of nonunion and no primary infection.

Abundance estimation and differential testing on strain level in metagenomics data

Motivation

Current metagenomics approaches allow analyzing the composition of microbial communities at high resolution. Important changes to the composition are known to even occur on strain level and to go hand in hand with changes in disease or ecological state. However, specific challenges arise for strain level analysis due to highly similar genome sequences present. Only a limited number of tools approach taxa abundance estimation beyond species level and there is a strong need for dedicated tools for strain resolution and differential abundance testing.

Methods

We present DiTASiC (Differential Taxa Abundance including Similarity Correction) as a novel approach for quantification and differential assessment of individual taxa in metagenomics samples. We introduce a generalized linear model for the resolution of shared read counts which cause a significant bias on strain level. Further, we capture abundance estimation uncertainties, which play a crucial role in differential abundance analysis. A novel statistical framework is built, which integrates the abundance variance and infers abundance distributions for differential testing sensitive to strain level.

Results

As a result, we obtain highly accurate abundance estimates down to sub-strain level and enable fine-grained resolution of strain clusters. We demonstrate the relevance of read ambiguity resolution and integration of abundance uncertainties for differential analysis. Accurate detections of even small changes are achieved and false-positives are significantly reduced. Superior performance is shown on latest benchmark sets of various complexities and in comparison to existing methods.

Availability and Implementation

DiTASiC code is freely available from https://rki_bioinformatics.gitlab.io/ditasic.

Supplementary information

Supplementary data are available at Bioinformatics online.

Comparison of pH and motility of the small intestine of healthy subjects and patients with symptomatic constipation using the wireless motility capsule

Gastrointestinal luminal pH shows a rise from the duodenum to the terminal ileum in healthy individuals. Our objectives were to compare the pH in the proximal small intestine (SI) (first 60 min of small intestinal transit) lumen of human volunteers and patients with symptomatic constipation; to quantify contractile pressure profiles of the proximal SI, and to assess the relationship between luminally-recorded contractile pressure and small intestinal transit times (SITT) of a non-disintegrating capsule that measures pH and pressure activity (wireless motility capsule). We used previously acquired records from 39 healthy subjects and 41 patients with symptomatic constipation. Mean pH (±SD) of the proximal SI was similar in healthy subjects and patients with constipation at 6.2 (±0.6) and 6.3 (±0.4), respectively. In 13 of the healthy subjects, pH did not rise uniformly in the proximal SI though the pH_median was 6.0 (5th, 95th percentiles 3.09, 7.06) and the pH fluctuated over a mean period of 28 min. Large inter-individual variability in frequency of pressure activity (Ct) and area under pressure curve (AUC) were observed in the proximal SI of healthy subjects and patients with constipation. Median AUC was 3996 mmHg s^-1 (5th, 95th percentiles 948, 16866 mmHg s^-1) in these two populations combined. Ct and AUC showed a strong direct linear correlation at r = 0.91, p < 1 × 10^-6. An inverse correlation (suggesting longer SITT with lower pressure activity) was observed between Ct/AUC and SITT in both healthy subjects and patients with symptomatic constipation. The pooled results for both groups showed: AUC and SITT correlation at r = -0.49, p < 1 × 10^-6. We concluded that both the frequency and amplitude of contractions in the proximal SI are important for the propagation of non-disintegrating capsules. The observed pH fluctuations in the proximal SI may impact supersaturation and precipitation of weakly basic drugs.

The role of Hemolysis during Extracorporeal Homologous Liver Perfusion

The rate of hemolysis and the behaviour of platelets were investigated during extracorporeal pig liver perfusions. In 8 animals whose iliac vessels had been cannulated and which were perfused for 6 hours in our circuit, packed cell volume, number of red blood cells and concentration of hemoglobin changed moderately after hemodilution with the machine's priming volume. Similiar results were obtained in 10 pigs which were perfused with homologous isolated pig livers up to 6 hours.

The best parameter to determine hemolysis was the plasma hemoglobin. Its level was twice as high as the initial value after mixture of the blood with the machine's priming volume in the iliac bypass experiments. Instead it remained practically unchanged throughout 6 hours of extracorporeal liver perfusions.

The liver seemed to act as a filter under these experimental conditions. It had similar filtration effects on the enzymes LDH and alpha-HBDG which are set free in hemolysis.

The decrease of platelets was more pronounced in extracorporeal liver perfusions than in iliac bypass experiments. Especially the functioning platelets decreased significantly in extracorporeal liver perfusions after 4–5 hours. The filtration effect of the liver seemed to be due to its intact RES. Xenogenous immunreactions played a minor role.

Radioimmunoscintigraphy with Anti-Thyroglobulin Monoclonal Antibodies

Monoclonal mouse antibodies to human thyroglobulin were conjugated to the cyclic dianhydride of DTPA. After radiolabelling with 111 In this compound was injected into nude mice bearing various human thyroid carcinomas. Repeated imaging studies were carried out 15 min to 50 h after tracer administration. In both papillary and undifferentiated thyroid carcinoma no significant uptake of radiolabeled anti-hTG-MAb was observed.

Guideline for radioimmunotherapy of rituximab relapsed or refractory CD20+ follicular B-cell nonHodgkin´s lymphoma

This guideline is a prerequisite for the quality management in the treatment of non-Hodgkin-lymphomas using radioimmunotherapy. It is based on an interdisciplinary consensus and contains background information and definitions as well as specified indications and detailed contraindications of treatment. Essential topics are the requirements for institutions performing the therapy. For instance, presence of an expert for medical physics, intense cooperation with all colleagues committed to treatment of lymphomas, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how the treatment has to be carried out technically. Here, quality control and documentation of labelling are of greatest importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with those colleagues (haematology-oncology) who propose, in general, radioimmunotherapy under consideration of the development of the disease.

Vergleich zwischen szintigraphischen und neurochirurgischen Befunden bei Hirntumoren

Bei einem selektiven Krankengut von 120 operierten Hirntumoren wurde der neurochirurgische Befund den Ergebnissen der Hirn-Szintigraphie gegenübergestellt. Die Auswahl der Fälle wurde auf die häufigen Tumor-Arten beschränkt, wie Meningeome, Astrozytome, Glioblastome, Oligodendrogliome, Neurinome und Metastasen. Aus dem Operationsbefund wurden die Lokalisation, die Tumorgröße, das Ausmaß der Vaskularisation sowie das Vorhandensein von Zysten und Nekrosen ausgewertet. Diese Daten wurden in Beziehung gesetzt zum Verhalten in der Radioangiographie und dem Grad der Aktivitätsanreicherung in den szintigraphischen Spätbildern.

Von den Hirntumoren waren 105 Fälle szintigraphisch nachweisbar.

In der Artdiagnostik war die Radioangiographie den szintigraphischen Spätbildern deutlich überlegen. Die Tumorgröße wurde szintigraphisch bei den Meningeomen etwas zu groß ermittelt, bei den übrigen Tumoren war die szintigraphische Tumorgröße kleiner als die im Operationsbefund angegebene.

Der Grad der Anreicherung in den Spätbildern zeigte eine Korrelation zur Vaskularisation. Dagegen bestand keine Korrelation zwischen der Vaskularisation und dem radioangiographischen Verhalten bei den Glioblastomen. Dieser Befund bedarf der weiteren Überprüfung. In der Hälfte der Fälle mit Zysten und Nekrosen waren Inhomogeneitäten in der Aktivitätsanreicherung des Tumors auf den Spätbildern erkennbar.

131I-Metaiodobenzylguanidine – A New Agent for Scintigraphic Imaging and Treatment of Pheochromocytoma

In 91 patients with a suspicion of pheochromocytoma 96 scintigraphies with 131I-metaiodobenzylguanidine were performed. The distribution of this radiopharmaceutical agent was studied. In about 71% we found uptake in the liver, in about 20% in the spleen and in about 6% in the gastrointestinal tract. In 13% of our patients a normal tracer uptake in the adrenal medulla was observed. In 23 patients adrenal or extra-adrenal lesion (s) were localized correctly, whereas one false-positive and one false-negative scintigramme was obtained. The 131I-MIBG imaging of adrenal and extra-adrenal, benign and malignant pheochromocytomas and adrenomedullary hyperplasia is highly specific. In the treatment of pheochromocytomas more experience is needed to present final results, but especially in malignant pheochromocytomas 131I-MIBG therapy may be useful.

The role of a small posterior malleolar fragment in trimalleolar fractures

Aims

The aim of this study was to investigate the effect of a posterior malleolar fragment (PMF), with < 25% ankle joint surface, on pressure distribution and joint-stability. There is still little scientific evidence available to advise on the size of PMF, which is essential to provide treatment. To date, studies show inconsistent results and recommendations for surgical treatment date from 1940.

Materials and Methods

A total of 12 cadaveric ankles were assigned to two study groups. A trimalleolar fracture was created, followed by open reduction and internal fixation. PMF was fixed in Group I, but not in Group II. Intra-articular pressure was measured and cyclic loading was performed.

Results

Contact area decreased following each fracture, while anatomical fixation restored it nearly to its intact level. Contact pressure decreased significantly with fixation of the PMF. In plantarflexion, the centre of force shifted significantly posteriorly in Group II and anteriorly in Group I. Load to failure testing showed no difference between the groups.

Conclusion

Surgical reduction of a small PMF with less than 25% ankle joint surface improves pressure distribution but does not affect ankle joint stability. Cite this article: Bone Joint J 2018;100-B:95–100.

Evidenzbasierte Medizin – Grundlagen und Anwendung in der Phlebologie

Die evidenzbasierte Medizin (EBM) ist zur internationalen Bewegung geworden, die Medizinern weltweit die zu einem Indikationsbereich bestehenden Erkenntnisse nutzbar machen will. Für die Behandlung wird der bestmögliche Grad angestrebt. Hierzu werden weltweit relevante Arbeiten in medizinischen Datenbanken erfasst und themenbezogen einer Gegenüberstellung und Analyse (systematic review) unterzogen. Im Ergebnis wird für ein Therapieverfahren oder ein Arzneimittel resümiert, unter welchen Umständen und aufgrund welcher Datenlage eine Wirksamkeit besteht.

Um die »Verlässlichkeit« von Studienergebnissen einzuschätzen, wurde ein System eingeführt, das Metaanalysen am höchsten und das Expertenurteil am geringsten bewertet. Zusammenstellung und systematische Bewertung werden von der Cochrane Collaboration geleistet, die national und international organisiert ist. Sie koordiniert die ärztliche Weiterbildung zum Thema EBM, erfasst und dokumentiert Systematic Reviews in der Cochrane Library.

Für die praktische Medizin wird EBM relevant, wenn wichtige therapeutische Felder mit systematischen Reviews analysiert wurden. Doch für große Teile der Medizin liegen keine ausreichenden Studien vor oder die publizierten Daten unterliegen einem so genannten Bias, z.B. durch Selektionseffekte bei der Patientenauswahl oder durch Nicht-Publikation negativer Ergebnisse. Die Grenzen und Möglichkeiten der EBM sollten bekannt sein, um die bereits geleistete Arbeit in der Praxis sinnvoll nutzen zu können.

Asymptomatic Clostridium difficile carriage rate post-fecal microbiota transplant is low: a prospective clinical and stool assessment

OBJECTIVES

We aimed to assess the asymptomatic Clostridium difficile carriage rates following fecal microbiota transplantation (FMT).

METHODS

All patients who underwent FMT for recurrent Clostridium difficile infection (CDI) via colonoscopy or sigmoidoscopy between June 2013 and April 2015 and had a minimum of 8-week follow-up post FMT at two tertiary care referral centres were included in the study. Patients were prospectively followed both clinically and with stool assessments for 8 weeks post FMT. Assessments occurred at 1 week and 4 weeks post FMT to assess for failure. Failure was defined as presence of diarrhoeal symptoms and a positive CDI stool test by polymerase chain reaction for toxin gene (PCR) at any time point during the 8-week follow-up period. CDI stool testing using PCR was performed at weeks 1 and 4 post FMT in asymptomatic patients as well.

RESULTS

167 patients were included. Twenty-eight patients (16.7% (28/167)) were FMT failures throughout the 8-week period. At week 1, seven patients had already failed the FMT. Of the remaining 160 patients, 144 were asymptomatic, and among these, 141 were negative for C. difficile toxin gene by PCR. This resulted in an asymptomatic carriage rate of 2.1% (3/144). At week 4, 143 patients had not yet failed FMT. Of these patients 129 patients were asymptomatic and among those, 125 were negative by PCR, resulting in an asymptomatic carriage rate of 3% (3/129).

CONCLUSIONS

Asymptomatic carriage after FMT is rare. This suggests that testing for cure after FMT in asymptomatic patients is not necessary.

Intensive Care in a Patient with Toxic Epidermal Necrolysis

Toxic epidermal necrolysis (TEN) is a serious adverse drug reaction with high lethality, which usually requires intensive-medical care. A 44-year-old man developed generalized exanthema with increasing exfoliation and mucosal involvement after taking allopurinol, ibuprofen, and etoricoxib. The clinical diagnosis of TEN was histologically confirmed. Prednisolone therapy with 3 mg/kg body weight (BW) was not able to prevent further progress to finally 80% of the body surface, and infliximab 5 mg/kg BW was given as a single dose. This prevented further progression of the TEN. Despite marked improvement in skin findings, the ICU stay was prolonged by a complex analgosedation, transient kidney failure, volume management, positioning therapy, and vegetatively impeded weaning. Moreover, there was colonization with multiresistant bacteria (MRSA and VRE). Nonetheless, the patient could be restored to health and was released after four weeks. Infliximab seems to be effective in the treatment of TEN, especially in cases of rapid progression. Moreover, patients with TEN are difficult to handle in intensive-medical care, whereby attention should especially be paid to sufficient pain therapy, and the positioning of the patient is a particular challenge.

Leishmaniasis auf Mallorca: Vorstellung eines ungewöhnlichen Verlaufs unter Immunsuppression

Das spanische Festland und die Balearen sind Endemiegebiete für die kutane und viszerale Leishmaniasis durch Leishmania infantum. Die kutane Leishmaniasis ist die häufigste Verlaufsform.

Der Hauptvektor, die Sandmücke Phlebotomus perniciosus, ist im gesamten Inselgebiet von Mallorca zu finden. Die Leishmaniasis zeichnet sich durch eine Vielzahl von klinischen Erscheinungsbildern aus. Der Immunstatus des Patienten spielt hierbei eine relevante Rolle für den Verlauf der Erkrankung und das Ansprechen der Therapie.