Advantages of simultaneous radial nerve and tendon reconstruction - a case report

Transection of the radial nerve is frequently associated with humeral shaft fractures that are part of a very complex upper extremity injury. In the presented case, a 19-year-old man with a 10-cm radial nerve defect with a need for nerve grafting to recover complete sensory and motor deficit of the radial nerve. In our case, at the same time we provided the tendon transfer of musculus (m.) pronator teres to m. extensor carpi radialis brevis, m. flexor carpi ulnaris to m. extensor digitorum communis, m. palmaris longus to m. extensor pollicis longus, and long sural nerve graft because of an extensive zone of the injury. The assumption was that if these two procedures are performed in one surgery, it will accelerate overall recovery, restore the functionality of the upper limb more quickly, and thus enable a faster recovery.

Ontogeny of human IgE-expressing B cells and plasma cells

Background

IgE‐expressing (IgE⁺) plasma cells (PCs) provide a continuous source of allergen‐specific IgE that is central to allergic responses. The extreme sparsity of IgE⁺ cells in vivo has confined their study almost entirely to mouse models.

Objective

To characterize the development pathway of human IgE⁺PCs and to determine the ontogeny of human IgE⁺PCs.

Methods

To generate human IgE⁺ cells, we cultured tonsil B cells with IL‐4 and anti‐CD40. Using FACS and RT‐PCR, we examined the phenotype of generated IgE⁺ cells, the capacity of tonsil B‐cell subsets to generate IgE⁺PCs and the class switching pathways involved.

Results

We have identified three phenotypic stages of IgE⁺PC development pathway, namely (i) IgE⁺germinal centre (GC)‐like B cells, (ii) IgE⁺PC‐like ‘plasmablasts’ and (iii) IgE⁺PCs. The same phenotypic stages were also observed for IgG1⁺ cells. Total tonsil B cells give rise to IgE⁺PCs by direct and sequential switching, whereas the isolated GC B‐cell fraction, the main source of IgE⁺PCs, generates IgE⁺PCs by sequential switching. PC differentiation of IgE⁺ cells is accompanied by the down‐regulation of surface expression of the short form of membrane IgE (mIgE_S), which is homologous to mouse mIgE, and the up‐regulation of the long form of mIgE (mIgE_L), which is associated with an enhanced B‐cell survival and expressed in humans, but not in mice.

Conclusion

Generation of IgE⁺PCs from tonsil GC B cells occurs mainly via sequential switching from IgG. The mIgE_L/mIgE_S ratio may be implicated in survival of IgE⁺ B cells during PC differentiation and allergic disease.

Intrinsic properties of germinal center-derived B cells promote their enhanced class switching to IgE

Background

Research on the origins and development of human IgE‐expressing (IgE⁺) cells is required for understanding the pathogenesis of allergy and asthma. These studies have been thwarted by the rarity of IgE⁺ cells in vivo and the low frequency of class switch recombination (CSR) to IgE ex vivo. To determine the main source of IgE⁺ cells, we investigated the relation between the phenotypic composition of tonsil B cells and the CSR to IgE ex vivo.

Methods

Human tonsil B cells were analyzed by flow cytometry (FACS) and cultured with IL‐4 and anti‐CD40 to induce CSR to IgE. Naïve, germinal center (GC), early GC (eGC), and memory tonsil B cells were isolated by FACS, and their capacities for IL‐4 and anti‐CD40 signaling, cell proliferation, and de novo class switching to IgE were analyzed by RT‐PCR and FACS.

Results

B cells from different tonsils exhibited varying capacities for CSR to IgE ex vivo. This was correlated with the percentage of eGC B cells in the tonsil at the outset of the culture. Despite relatively poor cell viability, eGC and GC B‐cell cultures produced the highest yields of IgE⁺ cells compared to naïve and memory B‐cell cultures. The main factors accounting for this result were the strength of IL‐4R and CD40 signaling and relative rates of cell proliferation.

Conclusions

This study shows that the maturation state of tonsil B cells determines their capacity to undergo class switching to IgE ex vivo, with the GC‐derived B cells yielding the highest percentage of IgE⁺ cells.

[Complex reconstruction with internal locking plate fixation for Charcot arthropathy]

BACKGROUND

Osteosynthesis and reposition of the Charcot foot is challenging with respect to choice of a proper implant. There is currently no international consensus regarding the optimal implant.

OBJECTIVES

Locking plates seem to be an innovative and stable method for reconstruction. The aim of this work is to analyze bone fusion, complications, pseudoarthrosis, and patient satisfaction.

METHODS

This paper presents a retrospective analysis of 63 consecutive Charcot feet treated between 2004 and 2014. The mean follow-up time was 2.4 years.

RESULTS

All Charcot feet treated between 2004 and 2014 were Sanders type II or III. A bony fusion was achieved in 50 % of the cases, 26 % had a functional pseudoarthrosis with intact implants and pain-free mobility, and 22 % showed no healing with broken implants. Conclusion Internal fixation with locking plates is superior to screw fixation only with regard to biomechanics. We prefer internal fixation plates to external fixation because of stability even in the case of pseudoathrosis and because of the learning curve.

[Visualization of local cortical defects in Charcot foot using microcomputed tomography]

BACKGROUND

In the pathogenesis of diabetic neuropathic osteoarthropathy (Charcot's foot) fractures cause chronic destruction of soft tissue and bone structure. To improve an early diagnosis of Charcot foot, modern diagnostic imaging is mainly based on magnetic resonance imaging (MRI), for example in relation to the detection of cortical bone fractures.

OBJECTIVES

In this study we investigated the cortical microstructure in cases of Charcot foot with respect to fractures and porosity in order to visualize local cortical defects. This may substantiate recent efforts in a reclassification based on MRI.

MATERIAL AND METHODS

Using microcomputed tomography (microCT) we investigated bone parameters, such as cortical thickness and porosity in order to quantify the local metatarsal microstructure in cases of Charcot foot.

RESULTS

All bone samples showed a high degree of cortical porosity including pores that perforated the cortical bone. The data suggest that areas with reduced cortical thickness coincide with large cortical pores that may serve as initial points for fractures. Whether the detected microfractures are physiological or artefacts of preparation could not be determined.

CONCLUSION

By means of microCT we were able to visualize and quantify the extent of cortical porosity for the first time in high resolution. The data suggest that both cortical fractures and cortical porosity play an important role in the pathogenesis in cases of Charcot foot.

[Arthroscopy of the upper ankle joint. A retrospective analysis of complications]

The purpose of this retrospective study was to analyse the complications of our arthroscopic procedures at the ankle joint. In all patients we evaluated the treatment protocols and in 111 patients (79.3%) we also evaluated the clinical and radiologic results. All in all we have found complications in 14 patients. In 4 cases we have seen a delayed wound healing, in 2 cases a superficial infection, in 3 cases a deep infection, in 3 cases a neural damage and in 2 cases a phlebothrombosis. Our study show, that the complication rate could be minimized by detailed knowledge of the anatomy, exact preoperative diagnostic and planing of the operation and careful preparation of the portals. The use of a laser also shows a tendency to a lower complication rate.

[Results of reconstruction of anterior cruciate ligament ruptures. Use of resorbable interference screws (minimum follow-up of 2.5 years)]

The purpose of this study was to assess the effects of biodegradable interference screw use in ACL reconstruction beyond the usual clinical historical and physical findings. The use of this material for interference screws has potential benefits if the problems of inflammation are minimal and the fixation properties are sufficient. There is no need for a second operation for removal and no complicating factor if revision surgery is necessary. A prospective study was initiated in May, 1993 to evaluate the use of biodegradable interference screws (Instrument Makar). Our patients were evaluated with the aid of the common OAK-score. The overall evaluation showed 89.5% excellent and good results, 7% fair results and 3.5% poor results. The average score was 90.7 points (63-100 points). The measurement with the arthrometer (KT 1000) showed a difference of up to 3 mm as compared to the knee joint not operated on in 24 (93%) of the patients. Four patients showed a 3 to 6 mm difference. A tibia translation of more than 4 mm was not measured in any case. The biodegradable interference screw is a safe and effective interference screw for fixation of the bone blocks for ACL reconstruction.