Posterior-only Stabilization for Traumatic Thoracolumbar Burst Fractures

Background

No consensus exists for the management of unstable thoracolumbar (TL) burst fractures. Surgical options include anterior, lateral, or posterior stabilization (or a combination), depending on the fracture. The potential benefits of anterior reconstruction come with increased operative time and associated morbidity. A posterior-only approach can offer stable correction without increased operative risks but may result in loss of kyphotic correction over time.

Purpose

To determine whether posterior-only stabilization is a viable treatment option for patients with traumatic TL fractures as opposed to anterior and combined approaches.

Methods

We performed a retrospective analysis of adult patients with TL burst fractures who underwent posterior­-only surgical intervention from 2005 to 2015. Operations were performed at two levels above and below the fractured segment using pedicle screw-rod fixation constructs with autograft and allograft. All patients received TL bracing for at least three months. Patients lost to follow­up were excluded.

Results

Sixty-four consecutive patients with posterior­-only stabilization were identified, with 18 lost to follow­up. Of the remaining 46 patients, 93% (n=43) were male and 7% (n=3) were female, with a mean age of 36.8 years. All patients were followed for 12 months. The mean time until the removal of the brace was 3.54 months. No patients required additional surgical intervention for spinal stabilization. Three patients experienced postoperative complications, all of which were related to infection.

Conclusions

Our data indicate that posterior­-only stabilization for traumatic TL burst fractures is a durable and effective option in select patients. The approach offers surgical intervention with a decreased perioperative risk as well as reduced morbidity and mortality, with a minimal increase in the risk of kyphotic deformity. Further prospective studies are necessary to validate these findings clinically.

Abdominal pseudocyst as a complication of ventriculoperitoneal shunt placement: Review of the literature and a proposed algorithm for treatment using 4 illustrative cases

BACKGROUND

Ventriculoperitoneal (VP) shunt placement is one of the most commonly performed procedures in neurosurgery. One rare complication is the formation of an abdominal pseudocyst, which can cause shunt malfunction.

CASE DESCRIPTIONS

We present four unique cases of abdominal pseudocyst formation. Our first patient initially presented with a right upper quadrant pseudocyst. Shunt was externalized and the distal end was revised with placement of catheter on the opposite side. He developed another pseudocyst within 5 months of shunt revision and developed another shunt failure. Our second patient had a history of shunt revisions and a known pseudocyst, presented with small bowel obstruction, and underwent laparotomy for the lysis of adhesions with improvement in his symptoms. After multiple readmissions for the same problem, it was thought that the pseudocyst was causing gastric outlet obstruction and his VP shunt was converted into a ventriculopleural shunt followed by percutaneous drainage of his pseudocyst. Our third patient developed hydrocephalus secondary to cryptococcal meningitis. He developed abdominal pain secondary to an abdominal pseudocyst, which was drained percutaneously with relief of symptoms. The fourth patient had a history of multiple shunt revisions and a previous percutaneous pseudocyst drainage that recurred with cellulitis and abscess secondary to hardware infection.

CONCLUSION

Abdominal pseudocysts are a rare but important complication of VP shunt placement. Treatment depends on etiology, patient presentation, and clinical manifestations. Techniques for revision include distal repositioning of peritoneal catheter, revision of catheter into pleural space or right atrium, or removal of the shunt completely.

Postoperative pain relief and functional outcome following total knee arthroplasty - a prospective comparative audit of three analgesic regimes

Pain control plays a key role in joint-replacement -surgery. As a surgeon the challenge is to reduce pain to an acceptable level in the post-operative period. The aim of the study was to assess the efficacy of bolus -local anaesthesia, infusion in to the surgical site and nerve blocks with femoral nerve catheter and its functional outcome. A prospective audit of 114 patients undergoing total knee arthroplasty were carried out.The patients were divided in to three groups : Group 1 (n = 27) received a bolus injection of 20 ml 0.25% levobupivacaine + 10 ml 0.25%bupivacaine + adrenaline + 30 ml saline. Group 2 (n = 39) received a bolus injection as on group 1 with 240 ml 0.25% bupivacaine infusion and 5 ml/hour using a Pain Buster pump. Group 3 (n = 48) received 30 ml 0.125% levobupivacaine to femoral (3-in-1) block with 30 ml 0.25% levobupivacaine to -sciatic nerve and introduction of a femoral nerve catheter. All patients were prescribed paracetamol 1 g QDS, Oxycontin 20 mg BD and Ibuprofen post -operatively. Pain was assessed with a Visual Analog Scale (VAS). The incidence of PONV was measured by PONY intensity score. The mean post-op VAS score for Group 3 was 4. The demand of oxynorm and NSAID were minimal in Group 3. The mean in patient stay for Group 3 was 3.1 days. The PONV intensity score was > 50 for 9 (36%) in Group 1, 15 (40%) in Group 2 and 9 (20%) in Group 3. There was loss of 20-30 degrees of flexion movements in Group 3 in the first 4 to 6 days post-op. Our study demonstrated that Regime 3 with the use of nerve blocks and femoral nerve catheter has given the maximum pain relief and good functional outcome following total knee replacement.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

The effect of total hip and hip resurfacing arthroplasty on vertical ground reaction force and impulse symmetry during a sit-to-stand task

BACKGROUND

The aim of this study was to determine the influence of total hip arthroplasty and hip resurfacing arthroplasty on limb loading symmetry before, and after, hip reconstruction surgery during a sit-to-stand task.

METHODS

Fourteen patients were recruited that were about to receive either a total hip prosthesis (n=7) or a hip resurfacing prosthesis (n=7), as well as matched controls. Patients performed a sit-to-stand movement before, 3 months after, and 12 months after surgery. Peak vertical ground reaction force and impulse were measured for each leg, from which ground reaction force and impulse symmetry ratios were calculated.

FINDINGS

Before surgery, hip resurfacing patients showed a small asymmetry which was not different to normal for ground reaction force (0.88(0.28) vs. 1.00(0.11); p=0.311) or impulse (0.87(0.29) vs. 0.99(0.09); p=0.324) symmetry ratios. Total hip patients offloaded their affected hip by 30% in terms of impulse symmetry ratio (0.71(0.36) vs. 0.99(0.23); p=0.018). At 3 months following surgery asymmetries were seen that were different to normal in both hip resurfacing patients for ground reaction force (0.77(0.16); p=0.007), and total hip patients for ground reaction force (0.70(0.15); p=0.018) and impulse (0.72(0.16); p=0.011) symmetry ratios. By 12 months after surgery total hip patients regained a symmetrical loading pattern for both ground reaction force (0.95(0.06); p=0.676) and impulse (1.00(0.06); p=0.702) symmetry ratios. Hip resurfacing patients, however, performed the task by overloading their operated hip, with impulse symmetry ratio being larger than normal (1.16(0.16); p=0.035).

INTERPRETATION

Physiotherapists should appreciate the need for early recovery of limb loading symmetry as well as subsequent differences in the responses observed with different prostheses.

Phenotypic evaluation of severely damaged ocular surface after reconstruction by cultured limbal epithelial cell transplantation

OBJECTIVE

To report the clinical outcome of autologous cultured limbal epithelial cell transplantation (CLECT) followed by deep anterior lamellar keratoplasty (DALK) in paediatric eyes and to correlate the clinical outcome with the phenotype of rejuvenated corneal epithelium.

METHODS

Four patients with total limbal stem cell deficiency (LSCD) underwent autologous CLECT. Cultivated cell sheets were transplanted onto the damaged ocular surface followed by DALK surgery. Excised corneal buttons were subjected to histopathological analysis. Data recorded included age, sex, laterality, nature of injury, follow-up period, severity of stem cell deficiency, visual acuity, Schirmer's test and impression cytology.

RESULTS

At a mean follow-up period of 19.5 ± 7.4 (range 9-26) months after CLECT, all 4 eyes showed epithelialized and clinically stabilized ocular surface. Manual DALK was performed in all 4 eyes, with a mean follow-up of 9.75 ± 4.5 (range 5-15) months. All eyes exhibited smooth and clear corneal epithelium with improved visual acuity. Excised corneal buttons demonstrated organized corneal epithelial morphology and showed expression of cornea-specific CK3/12 marker.

CONCLUSION

Restoration of severely damaged ocular surface following chemical injury by using 2-stage meticulous approaches offers a new modality for the treatment of severe LSCD. Transplantation of cultivated autologous limbal epithelial cell sheet followed by DALK surgery can efficiently restore the corneal phenotype with improved vision.

Computational Modeling Deduced Three Dimensional Structure of Cry1Ab16 Toxin from Bacillus thuringiensis AC11

The first theoretical structural model of newly reported Cry1Ab16 δ-endotoxin produced by Bacillus thuringiensis AC11 was predicted using homology modeling technique. Cry1Ab16 resembles the Cry1Aa protein structure by sharing a common three domains structure responsible in pore forming and specificity determination along with few structural deviations. The main differences between the two is in the length of loops, absence of α7b, α9a, α10b, α11a and presence of additional β12b, α13 components while α10a is spatially located at downstream position in Cry1Ab16. A better understanding of the 3D structure shall be helpful in the design of domain swapping and mutagenesis experiments aimed at improving toxicity.

Tuberculous lymphadenopathy: a multicentre operational study of 6-month thrice weekly directly observed treatment

SETTING

Eight operational locations for the Revised National Tuberculosis Control Programme in six Indian states.

OBJECTIVE

To assess the 6-month efficacy of an intermittent thrice-weekly directly observed treatment (DOT) regimen for tuberculous peripheral adenopathy and the need for prolongation of treatment to 9 months for non-resolution of lymphadenopathy.

DESIGN

Patients aged >5 years with tuberculous lymphadenopathy were included in the study. Patients were evaluated for resolution at repeat visits following treatment. Those with poor resolution at 6 months were randomised to extended treatment up to 9 months or observation without additional treatment.

RESULTS

Resolution of lymphadenopathy was observed at the end of 6 months in 517/551 (93.8%) patients. There was a significant difference in response among patients with and those without the presence of systemic symptoms. There was no association between treatment response and number, size, site, consistency and matting of lymphadenopathy. No differences in response were seen in the remaining 34 patients with or without extended treatment.

CONCLUSION

The operational efficacy of 6-month thrice-weekly DOT for peripheral tubercular lymphadenopathy was satisfactory. There was no evidence of additional benefits of prolonging treatment to 9 months.

Peculiar reduction of graphene oxide into graphene after diffusion in exponentially growing polyelectrolyte multilayers

In the present work, in situ reduction of graphene oxide (GO) into graphene was preformed, after diffusion in exponentially growing polyelectrolyte multilayers, using sodium citrate as the reducing agent. First, the graphene oxide was obtained by treating a commercial grade of Expanded Graphite (EG). Based on XRD and Raman spectroscopy results, a complete exfoliation of graphene nanopellets down to one layer was achieved during the oxidation process. Secondly, the diffusion of GO was carried out in an exponentially growing polyelectrolyte multilayer film made from poly(diallyldimethylammonium chloride) as the polycation and from poly(acrylic acid) as the polyanion. Electrical conductivity of the GO based films was measured during the reduction process as a function of time. The conductivity reached values of the order of 10(-4) S cm(-1), whereas the pristine polyelectrolyte multilayer was highly insulating (∼10(-8) S cm(-1)). The conductivity also reached a maximal value after about 24 h of reduction and decreased for longer reduction duration. Some tentative explanations for this peculiar finding will be given.

Retinoblastoma

Retinoblastoma is the most common intraocular malignancy in children and one of the very few life-threatening ophthalmic conditions. Genetically, the disease may be heritable or non-heritable. It can have unilateral or bilateral involvement and can present either sporadically or with a positive family history. Leukocoria and strabismus are the most common presentations. Diagnosis is made by indirect ophthalmoscopy aided by imaging techniques. Multidisciplinary management is aimed at saving lives, salvaging the globe and maintaining good vision. The use of neoadjuvant chemotherapy and focal treatments, such as cryotherapy, laser photocoagulation, transpupillary thermotherapy, brachytherapy and periocular chemotherapy, form the mainstay of globe preserving treatment in retinoblastoma. In developing countries, retinoblastoma is unfortunately accompanied by a high mortality rate due to delayed diagnosis made at advanced stages of the disease. Early diagnosis and timely management are vital for a good prognosis.

Evaluating most probable number method to count and isolate viable methylotrophs

Nine different receptacles were tested with the MPN method to determine which receptacle was most reliable and economical for MPN counts. Results showed that 96 well PCR plate were the best vessels for this type of analysis and facilitated the isolation of viable Methylotrophs.

Prevalence of bronchial asthma in school children of 6-13 years of age in Shimla city

BACKGROUND

Asthma is a major public health problem worldwide. However, there is limited data on asthma prevalence among school children in Shimla. The present study was undertaken to determine the prevalence of asthma in Shimla city and also to examine the different factors influencing its occurrence.

METHODS

This was a questionnaire-based study (International Study of Asthma and Allergies in Childhood [ISAAC] protocol) carried out in four randomly selected schools in the city of Shimla. The questionnaire was pre-tested in 50 school children. The age group included in the study was 6-13 years. The questionnaire was distributed to all the children (n = 1136). A response rate of 89.5% was achieved. The socio-economic status was determined on the basis of monthly income (cumulative square root value method). The ISAAC questionnaire was given standard scores. Various factors influencing the prevalence of asthma, such as socio-economic status, history of asthma and other allergic disorders in the family, type of cooking fuel used, history of active and passive smoking were elucidated from the history.

RESULTS

Overall prevalence of asthma in our study was found to be 2.3 percent. Boys had a higher prevalence (3.1%) than girls (1.4%). We found a significant association between asthma prevalence and family history of asthma and other atopic manifestations. There was no significant association of socio-economic factors and exposure to smoking with prevalence of asthma.

CONCLUSION

In the present study, the prevalence of bronchial asthma in school children in the age group of 6-13 years is 2.3 percent.

Interactions among peripheral perfusion, cardiac activity, oxygen saturation, thermal profile and body position in growing low birth weight infants

AIMS

To investigate the correlation between the 'perfusion index' (PI) and other commonly used estimates of cutaneous blood flow [heart rate (HR), surface temperatures (ST) and central-to-peripheral thermal gradients (C-P grad)] and to use this new non-invasive tool to compare differences between prone and supine sleep position in low birth weight (LBW) infants.

METHODS

Six-hour continuous recordings of pulse oximetry, cardiac activity and absolute ST from three sites (flank, forearm and leg), along with minute-to-minute assessment of behavioural states were performed in 31 LBW infants. Infants were randomly assigned to the prone or supine position for the first 3 h and then reversed for the second 3 h. PI data were correlated with HR and C-P grad, and compared across sleep positions during quiet sleep (QS) and active sleep (AS).

RESULTS

Perfusion index correlated significantly with HR (r(2) = 0.40) and flank-to-forearm thermal gradient (r(2) = 0.28). In the prone position during QS, infants exhibited higher PI (3.7 +/- 0.9 vs. 3.1 +/- 0.7), HR (158.4 +/- 8.9 vs. 154.1 +/- 8.8 bpm), SpO(2) (95.8 +/- 2.6 vs. 95.2 +/- 2.6%), flank (36.7 +/- 0.4 vs. 36.5 +/- 0.4 degrees C), forearm (36.1 +/- 0.6 vs. 35.5 +/- 0.4 degrees C) and leg (35.4 +/- 0.7 vs. 34.7 +/- 0.7 degrees C) temperatures and narrower flank-to-forearm (0.6 +/- 0.4 vs. 0.9 +/- 0.3 degrees C) and flank-to-leg (1.3 +/- 0.6 vs. 1.8 +/- 0.7 degrees C) gradients, compared to those of the supine position. Similar differences were observed during AS.

CONCLUSION

Perfusion index is a good non-invasive estimate of tissue perfusion. Prone sleeping position is associated with a higher PI, possibly reflecting thermoregulatory adjustments in cardiovascular control. The effects of these position-related changes may have important implications for the increased risk for sudden infant death syndrome in prone position.

Hydatid disease of the lung mimicking a pericardial cyst

We report a young girl who presented to us with chest discomfort and had a paracardiac mass on chest radiograph. Computerised tomographic (CT) scan of the thorax was suggestive of pericardial cyst. Hydatid serology was negative. The cyst was excised.

Sudden collapse of a young female cross country runner

The case is reported of a young previously healthy female cross country runner who collapsed on completion of a cross country run. The cause of the collapse was non-cardiogenic pulmonary oedema as a manifestation of hyponatraemic encephalopathy. The concurrent occurrence of non-cardiogenic pulmonary oedema and encephalopathy due to hyponatraemia is unusual.

Prevalence of tobacco use among school going youth in North Indian States

BACKGROUND

Tobacco use, which is the cause of several respiratory diseases, generally starts in the teens. Global Youth Tobacco Survey (GYTS) is an international initiative to investigate the tobacco use in school going youth of 13 to 15 years of age. This report describes the GYTS findings in the North Indian region.

METHODS

A two-stage cluster sample was used with selection of schools on probability proportional to enrollment size followed by systematic equal probability sampling with a random start of classes from each school. The 85-item questionnaire included 'core GYTS' and other additional questions. Data analysis was performed using EpiInfo 3.2 software and the results accounted for the complex sampling design and weighting factors in the data set.

RESULTS

The sample consisted of 9319 students out of the total eligible population of 30488 from 100 schools. The prevalence of ever-use of tobacco varied between 2.9 to 8.5% in boys and 1.5 to 9.8% in girls. The prevalence was highest in Chandigarh and lowest in Punjab. Between 16 to 46% of students were exposed to the habit of tobacco among parents or friends. There were 10 to 34% students who were passively exposed to environmental tobacco smoke.

CONCLUSION

Tobacco use is present in up to 10 percent of school going youth in the region. A majority of them had desired to quit. Tobacco control and cessation programmes therefore, remain important health issues.

Sleeping position and electrocortical activity in low birthweight infants

OBJECTIVE

To evaluate the effects of prone and supine sleeping positions on electrocortical activity during active (AS) and quiet (QS) sleep in low birthweight infants.

DESIGN

Randomised/crossover study.

SETTING

Infant Physiology Laboratory at Children's Hospital of New York.

PATIENTS

Sixty three healthy, growing, low birthweight (birth weight 795-1600 g) infants, 26-37 weeks gestational age.

INTERVENTIONS

Six hour continuous two channel electrocortical recordings, together with minute by minute behavioural state assignment, were performed. The infants were randomly assigned to prone or supine position during the first three hours, and positions were reversed during the second three hours.

OUTCOME MEASURES AND RESULTS

Fast Fourier transforms of electroencephalograms (EEGs) were performed each minute and the total EEG power (TP), spectral edge frequency (SEF), absolute (AP) and relative (RP) powers in five frequency bands (0.01-1.0 Hz, 1-4 Hz, 4-8 Hz, 8-12 Hz, 12-24 Hz) were computed. Mean values for TP, SEF, AP, and RP in the five frequency bands in the prone and supine positions during AS and QS were then compared. In the prone sleeping position, during AS, infants showed significantly lower TP, decreased AP in frequency bands 0.01-1.0 Hz, 4-8 Hz, 8-12 Hz, 12-24 Hz, increased RP in 1-4 Hz, and a decrease in SEF. Similar trends were observed during QS, although they did not reach statistical significance.

CONCLUSIONS

The prone sleeping position promotes a shift in EEG activity towards slower frequencies. These changes in electrocortical activity may be related to mechanisms associated with decreased arousal in the prone position and, in turn, increased risk of sudden infant death syndrome.