Influence of screw type on initial coronal and sagittal radiological correction with hybrid constructs in adolescent idiopathic scoliosis. Correction priorities

BACKGROUND

Pedicle screw constructs for spinal instrumentation in patients with adolescent idiopathic scoliosis (AIS) are effective in providing coronal plane correction but can result in loss of kyphosis, which in turn can lead to loss of lordosis. Hybrid constructs have been found superior over pedicle screw constructs in terms of thoracic kyphosis restoration. In this study, our objective was to compare outcomes with monoaxial versus polyaxial screws in an AIS population treated with hybrid constructs.

HYPOTHESIS

Monoaxial screws provide better correction in the coronal plane but result in loss of thoracic kyphosis, whereas thoracic kyphosis is preserved when polyaxial screws are used.

MATERIAL AND METHODS

We retrospectively analysed data from 60 patients (mean age, 15years) with Lenke 1, 2, or 3 AIS treated using a hybrid construct with self-retaining bilaminar hook claws cranially, pedicle screws between the last instrumented vertebra and T11 caudally, and sublaminar universal clamps between the two extremities of the construct. Monoaxial screws were used in the first 30 patients (MS group) and polyaxial screws in the next 30 patients (PS group). Student's t test was performed to compare the two groups in terms of thoracic Cobb angle correction and T4-T12 kyphosis 3 months after surgery.

RESULTS

No significant preoperative differences were found between the two groups. At last follow-up, the residual Cobb angle was significantly greater in the PS group than in the MS group (20.3° versus 15°) with a percentage of correction of 72.1% in the MS group versus 64.8% in the PS group. In the sagittal plane, the thoracic kyphosis was significantly greater in the PS group than in the MS group (26.6° versus 23°).

DISCUSSION

This preliminary study shows that, even within a population managed using hybrid constructs, which are associated with less iatrogenic hypokyphosis, differences exist according to the technique used. The importance of sagittal spinal balance has been abundantly documented in the literature, and sagittal malalignment, particularly due to iatrogenic factors, is associated with poorer clinical outcomes in adults with spinal deformities. Therefore, there is a critical need to determine whether the treatment priority is optimal correction in the coronal plane or in the sagittal plane. We believe that the main focus should be sagittal plane correction, even at the expense of a slight decrease in coronal plane correction. Long-term studies are needed to confirm our preliminary findings.

[Excess mortality and prolongation of stay due to bloodstream infections caused by multiresistant pathogens in Germany]

BACKGROUND

Multiresistant pathogens cause substantial excess mortality and prolongation of hospital stay. However, until now there are no reliable estimates for Germany.

METHOD

Based on data of three recent publications from Europe and current German data on bloodstream infections because of methicillin-resistant S. aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing E. coli we calculated the number of patients dying from bloodstream infections because of MRSA- instead of methicillin-susceptible S. aureus (MSSA) or ESBL-producing E. coli instead of non-ESBL E. coli.

RESULTS

About 421 patients died in 2010 because they suffered from MRSA bloodstream infection instead of MSSA bloodstream infection. Excess mortality for bloodstream infections because ESBL-producing E. coli instead of non-ESBL E. coli was about 256 cases. Considering that bloodstream infections with other multiresistant pathogens also lead to higher mortality, between 800 to 1000 deaths can be expected because of the resistant variant of the pathogens. In addition, bloodstream infections with multiresistant pathogens lead to more than 12000 additional days in hospital in Germany.

CONCLUSION

Although this article does not include the burden of other healthcare-associated infections due to multiresistant pathogens the data for bloodstream infections alone demonstrate substantial excess burden and costs.

High prevalence of extended-spectrum-β-lactamase-producing Enterobacteriaceae in organic and conventional retail chicken meat, Germany

OBJECTIVES

To determine the prevalence of extended-spectrum β-lactamase (ESBL) production in Enterobacteriaceae in retail chicken meat in Germany.

METHODS

A total of 399 chicken meat samples from nine supermarket chains, four organic food stores and one butcher's shop in two geographically distinct regions (Berlin and Greifswald) were screened for ESBL production using selective agar. Phenotypic ESBL isolates were tested for bla(TEM), bla(CTX-M) and bla(SHV) genes using PCR and DNA sequencing. Antibiotic coresistances were determined and strain typing was performed using PCR-based phylogenetic grouping and XbaI-PFGE.

RESULTS

A total of 185 confirmed ESBL isolates were obtained from 175 samples (43.9%) from all tested sources. The majority of isolates were Escherichia coli producing ESBL types SHV-12 (n = 82), CTX-M-1 (n = 77) and TEM-52 (n = 16). No differences could be observed in the prevalence of ESBL producers between organic and conventional samples. 73.0% of the ESBL producers showed coresistance to tetracycline, 35.7% to co-trimoxazole and 7.6% to ciprofloxacin. Strain typing of selected E. coli isolates from Berlin revealed identical macrorestriction patterns for several isolates from samples taken from the same stores.

CONCLUSIONS

This is the first comprehensive study from Germany showing a high prevalence of TEM-, CTX-M- and SHV-type ESBLs in Enterobacteriaceae isolated from retail chicken meat. The high rate of coresistance to different classes of antibiotics in the ESBL producers might reflect the common veterinary usage of these and related substances. There is an urgent need to further evaluate the role of poultry in the transmission of highly resistant ESBL-producing bacteria in humans.

Reciprocal sagittal alignment changes after posterior fusion in the setting of adolescent idiopathic scoliosis

PURPOSE

Surgical adolescent idiopathic scoliosis (AIS) management can be associated with loss of thoracic kyphosis and a secondary loss of lumbar lordosis leading to iatrogenic flatback. Such conditions are associated with poorer clinical outcomes during adulthood. The aim of this study was to evaluate sagittal plane reciprocal changes after posterior spinal fusion in the setting of AIS.

METHODS

Thirty consecutive adolescents (mean age 14.6 years) with AIS Lenke 1, 2 or 3 were included in this retrospective study with 2 year follow-up. Full-spine standing coronal and lateral radiographs were obtained preoperatively, at 3 and 24 months postoperatively. Coronal Cobb angle, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured. Surgical procedure was similar in all the cases, with use of pedicular screws between T11 and the lowest instrumented vertebra (≥L2), sublaminar hooks applied in compression at the upper thoracic level and sub-laminar bands and clamps in the concavity of the deformity. Statistical analysis was done using t test and Pearson correlation coefficient.

RESULTS

Between preoperative and last follow-up evaluations a significant reduction of Cobb angle was observed (53.6° vs. 17.2°, p < 0.001). A significant improvement of the instrumented thoracic kyphosis, TK (19.7° vs. 26.2°, p < 0.005) was noted, without difference between 3 and 24 months postoperatively. An improvement in lumbar lordosis, LL (43.9° vs. 47.3°, p = 0.009) was also noted but occurred after the third postoperative month. A significant correlation was found between TK correction and improvement of LL (R = 0.382, p = 0.037), without correlation between these reciprocal changes and the amount of coronal correction.

CONCLUSION

Results from this study reveal that sagittal reciprocal changes occur after posterior fusion when TK is restored. These changes are visible after 3 months postoperatively, corresponding to a progressive adaptation of patient posture to the surgically induced alignment. These changes are not correlated with coronal plane correction of the deformity. In the setting of AIS, TK restoration is a critical goal and permits favorable postural adaptation. Further studies will include pelvic parameters and clinical scores in order to evaluate the impact of the noted reciprocal changes.

Understaffing, overcrowding, inappropriate nurse:ventilated patient ratio and nosocomial infections: which parameter is the best reflection of deficits?

BACKGROUND

In stressed and high-throughput systems, periodic overcrowding (high bed occupancy) and understaffing (low nurse:patient ratio) are widely described risk factors for nosocomial infections.

AIM

The impact of bed occupancy (patient:bed ratio), nurse:patient ratio and nurse:ventilated patient ratio on nosocomial bloodstream infections (BSI) and pneumonia were investigated in 182 intensive care units (ICU).

METHODS

The ICUs reported monthly data on device use and nosocomial device-associated infections to the German hospital surveillance system for nosocomial infections in 2007. Information on the number of healthcare workers on the ward per 24h in 2007 and structure parameters was obtained by questionnaires. The association between occupancy or staff parameters and the number of nosocomial infections per month was analysed using generalized estimating equation models.

FINDINGS

In total, 1313 cases of pneumonia and 513 cases of BSI were reported from 182 ICUs with 1921 surveillance months and 563,177 patient-days. Fewer nosocomial infections were associated with a higher nurse:ventilated patient ratio [adjusted incidence rate ratio 0.42 (95% confidence interval 0.32-0.55) for months with nurse:ventilated patient ratios >75th percentile compared with ≤ 25 th percentile]. Interestingly, the nurse:patient ratio was not a significant parameter with respect to the occurrence of BSI and pneumonia. High bed occupancy (>75th percentile) was associated with fewer nosocomial infections.

CONCLUSION

A staffing parameter that reflects the intensity of care, such as the nurse:ventilated patient ratio, may enable better evaluation of workload and resources, especially at a time when nursing resources are being reduced but nosocomial infections are increasing.

Increase of patients co-colonised or co-infected with methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium or extended-spectrum β-lactamase-producing Enterobacteriaceae

PURPOSE

To determine the incidence of patients co-colonised or co-infected with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium or extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in four German tertiary care hospitals.

METHODS

This study was conducted at four tertiary care hospitals (all with >1,000 beds) in different geographic regions in Germany (Berlin in the east, Luebeck in the north, Freiburg in the southwest and Nuernberg in the southeast). Routine surveillance data on MRSA, vancomycin-resistant enterococci (VRE) and ESBL-producing bacteria were analysed from 2007 to 2009. Co-colonisation or co-infection was defined as a patient having positive cultures for at least two of the following resistant pathogens: MRSA, VRE faecium or different species of ESBL-producing Enterobacteriaceae within one calendar year.

RESULTS

A total of 896,822 patients were analysed, of which 10,066 patients harboured MRSA, VRE faecium and/or ESBL-producing Enterobacteriaceae, and 542 patients co-harboured at least two of those resistant pathogens. In 2009, 7.6% of the MRSA patients, 13.7% of the VRE faecium patients and even 16.1% of the ESBL-producing Enterobacteriaceae patients were co-colonised or co-infected. The incidence of patients with co-infection or co-colonisation increased steadily from 5 (2007) to 7 per 10,000 patients (2009).

CONCLUSIONS

Patients harbouring ESBL-producing Enterobacteriaceae or VRE faecium had a higher risk of being co-colonised or co-infected compared to what was to be extrapolated from their overall incidence. This might be linked to their gastrointestinal reservoir and impracticality to decolonise the gut of resistant VRE and ESBL-producing Enterobacteriaceae.

Nosocomial methicillin resistant Staphylococcus aureus pneumonia - epidemiology and trends based on data of a network of 586 German ICUs (2005-2009)

The epidemiology of MRSA pneumonia varies across countries. One of the most import risk factors for the development of nosocomial MRSA pneumonia is mechanical ventilation. Methicillin resistance in S. aureus ventilator associated pneumonia (VAP) ranged between 37% in German, 54% in the US American and 78% in Asian and Latin American ICUs. In 2009, the incidence density of nosocomial VAP caused by MRSA was 0.28 per 1000 ventilation days in a network of 586 German ICUs. Incidences peaked in neurological and neurosurgical ICUs. Crude hospital mortality in studies performed after 2005 lay between 27% and 59% and attributable MRSA pneumonia mortality at 40%. Since 2005, US American and German data indicate decreasing trends for MRSA pneumonia. Measures to reduce MRSA pneumonia or to control the spread of MRSA include hand hygiene, standard and contact precautions, oral contamination with chlor hexidine, skin decontamination with antiseptics, screening, and (possibly) patient isolation in a single room.