Complications of standard versus long cephalomedullary nails in the treatment of unstable extracapsular proximal femoral fractures: A randomized controlled trial

AIMS

To compare in a prospective randomized trial the mechanical complications in patients with unstable extracapsular proximal femur fractures without subtrochanteric extension (AO/OTA 31-A2 and 31-A3) METHODS: We prospectively studied 182 patients with unstable extracapsular proximal femur fractures without fractures lines extending more than 3 cm below the lesser trochanter, randomized to receive either a 'standard' (240 mm) nail or a long nail and followed them up for 1 year.

RESULTS

We found no difference in the incidence of mechanical or general complications between the two groups, no cut-outs, no fractures of the tip the implant, 1 cut-through and 2 malrotations in the LN group, 2 non-unions that were reoperated, one on each group. The commonest complication was blade lateral migration, 13 (14%) patients in SN and 6 (9%) in the LN. The operating time was shorter in the SN group 51 minutes compared to 67 minutes in the LN group (p=0.000075). The mortality at 1,3 and 12 months in the SN group was of 2%, 6%, 12% while in the LN group was 12%, 18% and 22%. These differences where significative at 1 (p=0.007) and 3 months (p=0.013), but not at 12 months (p=0.075).

CONCLUSIONS

We recommend the use of standard nails (240 mm) for this group of fractures, since it does not produce more mechanical complications, and it is faster, cheaper and easier to interlock distally.

Integrating ecotoxicity and chemical approaches to compare the effects of ZnO nanoparticles, ZnO bulk, and ZnCl2 on plants and microorganisms in a natural soil

This work compared the toxicity of ZnO nanoparticles (ZnO-NPs), ZnO bulk, and ZnCl2 on microbial activity (C and N transformations and dehydrogenase and phosphatase activities) and their uptake and toxic effects (emergence, root elongation, and shoot growth) on three plant species namely wheat, radish, and vetch in a natural soil at 1000 mg Zn kg(-1). Additionally, plants were also tested at 250 mg Zn kg(-1). The effects of the chemical species on Zn extractability in soil were studied by performing single and sequential extractions. ZnCl2-1000 presented the highest toxicity for both taxonomic groups. For microorganisms, ZnO-NPs demonstrated adverse effects on all measured parameters, except on N transformations. The effects of both ZnO forms were similar. For plants, ZnO-NPs affected the growth of more plant species than ZnO bulk, although the effects were small in all cases. Regarding accumulation, the total Zn amounts were higher in plants exposed to ZnO-NP than those exposed to ZnO bulk, except for vetch shoots. The soil sequential extraction revealed that the Zn concentration in the most labile forms (water soluble (WS) and exchangeable (EX)) was similar in soil treated with ZnO (NP and bulk) and lower than that of ZnCl2-treated soil, indicating the higher availability of the ionic forms. The strong correlations obtained between WS-Zn fraction and the Zn concentrations in the roots, shoots, and the effects on shoot weight show the suitability of this soil extraction method for predicting bioavailable Zn soil for the three plant species when it was added as ZnO-NPs, ZnO bulk, or ZnCl2. In this work, the hazard associated with the ZnO-NPs was similar to ZnO bulk in most cases.

Toxicity of ZnO nanoparticles, ZnO bulk, and ZnCl₂ on earthworms in a spiked natural soil and toxicological effects of leachates on aquatic organisms

The present study assessed the uptake and toxicity of ZnO nanoparticles (NPs), ZnO bulk, and ZnCl₂ salt in earthworms in spiked agricultural soils. In addition, the toxicity of aqueous extracts to Daphnia magna and Chlorella vulgaris was analyzed to determine the risk of these soils to the aquatic compartment. We then investigated the distribution of Zn in soil fractions to interpret the nature of toxicity. Neither mortality nor differences in earthworm body weight were observed compared with the control. The most sensitive end point was reproduction. ZnCl₂ was notably toxic in eliminating the production of cocoons. The effects induced by ZnO-NPs and bulk ZnO on fecundity were similar and lower than those of the salt. In contrast to ZnO bulk, ZnO-NPs adversely affected fertility. The internal concentrations of Zn in earthworms in the NP group were greater than those in the salt and bulk groups, although bioconcentration factors were consistently <1. No relationship was found between toxicity and internal Zn amounts in earthworms. The results from the sequential extraction of soil showed that ZnCl₂ displayed the highest availability compared with both ZnO. Zn distribution was consistent with the greatest toxicity showed by the salt but not with Zn body concentrations. The soil extracts from both ZnO-NPs and bulk ZnO did not show effects on aquatic organisms (Daphnia and algae) after short-term exposure. However, ZnCl₂ extracts (total and 0.45-μm filtered) were toxic to Daphnia.

Plasticity of xyloglucan composition in bean (Phaseolus vulgaris)-cultured cells during habituation and dehabituation to lethal concentrations of dichlobenil

Bean cells that have been habituated to grow in a lethal concentration (12 μM) of 2,6-dichlorobenzonitrile (dichlobenil or DCB, a cellulose biosynthesis inhibitor) are known to have decreased cellulose content in their cell walls. Xyloglucan, which is bound to cellulose and together with it forms the main loading network of plant cell walls, has also been described to decrease in habituated cells, but whether the change on cellulose affects the xyloglucan structure besides its abundance has not been analyzed. Fragmentation analysis with xyloglucan-specific endoglucanase (XEG) and endocellulase revealed that habituation to DCB caused a change in the fine structure of xyloglucan, namely a decrease in fucosyl residues attached to the galactosyl-xylosyl residues along the glucan backbone. After the removal of herbicide from the medium (dehabituated cells), xyloglucan recovered its fucosyl residues. In addition, some cello-oligosaccharides could be detected only in habituated cells' xyloglucan digested by XEG and endocellulase, corresponding to a glucan covalently bound or co-precipitated with the hemicelluloses. These results show that structural flexibility of cell walls relies in part on the plasticity of xyloglucan composition and opens up new perspectives to further research in this field.