Kyphoplasty Augmentation in Thoracolumbar Spine - Clinical Outcomes after 2 Years.

PURPOSE OF THE STUDY With the ageing of population the vertebral insufficiency fractures are increasing in number and occur ever more frequently. Symptomatic relief is often difficult to achieve by non-operative treatment. The aim of this study was to determine the level of pain relief and functional outcomes in patients who failed initial non-operative treatment and, because of persisting or growing symptoms, underwent kyphoplasty. MATERIAL AND METHODS Total number of 303 patients who underwent balloon kyphoplasty between January 2011 and December 2016 were included in our study. These 303 patients had 357 surgeries. This is a retrospective review of a prospectively updated database maintained by our spinal surgery department. In total, 575 levels were augmented. The patients were mostly females (246). The age of the patients ranged from 30 years to 98 years, with the mean age being 72.6 years. The average follow-up for our series was 17.2 months (2-63 months). Pain relief was assessed using the Visual Analogue Scale (VAS) and functional outcome using the Oswestry Disability Index (ODI). RESULTS The average pre-operative VAS was 6.34 (p = 0.00003). At 6 weeks postoperatively the average VAS decreased to 3.80 (p = 0.00000). In our series, the VAS scores showed a progressive decline progressing from the mean value of 3.18 (p = 0.15890) at 1 year to the mean value of 2.85 (p = 0.00205) at 2 years. The average pre-operative ODI was 25.65 (p = 0.03604). At 6 weeks, the value improved to 17.69 (p = 0,00120) and further improvements were seen at 1 year (ODI 14.13) and at 2 years (ODI 12.08). In our series no clinically significant complications were reported. The social drift was observed in 17 patients in our study. DISCUSSION The pain relief and the improvement of functional outcomes were maintained even at a two-year follow-up. No clinically significant complications were reported that would require further surgical intervention and that would affect the good clinical results of our study. CONCLUSIONS Balloon kyphoplasty proved to be a safe surgical technique and should be considered in patients with an ongoing pain following vertebral insufficiency fractures that do not improve with the initial non-operative treatment. Cement augmentation significantly improves pain levels and as well functional status in elderly patients. Key words:cement augmentation, osteoporotic fracture, kyphoplasty, vertebroplasty, osteoporotic spine fracture.

Graphene electrodes for adaptive liquid crystal contact lenses.

The superlatives of graphene cover a whole range of properties: electrical, chemical, mechanical, thermal and others. These special properties earn graphene a place in current or future applications. Here we demonstrate one such application - adaptive contact lenses based on liquid crystals, where simultaneously the high electrical conductivity, transparency, flexibility and elasticity of graphene are being utilised. In our devices graphene is used as a transparent conductive coating on curved PMMA substrates. The adaptive lenses provide a + 0.7 D change in optical power with an applied voltage of 7.1 Vrms - perfect to correct presbyopia, the age-related condition that limits the near focus ability of the eye.

Impact of kyphoplasty treatment for vertebral compression fractures on pain and function in 105 patients.

PURPOSE OF THE STUDY: Vertebral compression fractures are very common. Symptomatic relief with conservative therapy is often difficult to achieve. Balloon kyphoplasty is a relatively new technique which stabilises the vertebral body and restores spinal alignment in recent fractures, it achieves significant pain relief and improved functional outcome is reported. The aim of this prospective study was to determine the level of pain relief and functional outcome in patients who were initially treated conservatively for 4-6 weeks and if symptoms did not have tendency to resolve, then had kyphoplasty surgery. MATERIAL AND METHODS: 105 patients underwent balloon kyphoplasty between April 2006 and August 2010 and had 1 year follow up. Total 170 levels were augmented, 65% (n=68) of patients were female and the average age was 74 years. Pain relief was assessed using visual analogue score (VAS) and functional outcome using Oswestry Disability Index (ODI). RESULTS: Results showed decrease of the average pre-operative VAS from 8.2 to 4.4 in the immediate postoperative period (p=0.000). This dramatic improvement remained and was 4.1 at 6 weeks, 3.3 at 6 months and 3.6 at 1 year. The average pre-operative ODI was 58. This improved to 47 in the immediate post-operative period (p=0.002). At 6 weeks this had improved further to 40 and further improvements were seen at 6 months (ODI 37) and 1 year (ODI 38). The average screening time was 2 minutes and 20 seconds. The average volume of cement used per level was 5.5 cm3. Radiographic measurements were performed by independent radiologist. The average pre-operative vertebral angle was 11.6° and 10.9° postoperatively. This was maintained throughout the follow up. This represented a negligible 6% improvement in vertebral body angle. We did not experience any clinically significant complications, we have encountered 11 minor complications which did not require any additional measures (cement leaks, penetration of the vertebral body margins by balloons or K wires and rib fractures). DISCUSSION: Pain relief and improvement of functional outcome was sustained after one year. Limited number of patients who had 2 year follow up showed trend of minimal deterioration of both parameters (VAS and ODI). This can be explained by incidence of few adjacent segment fractures and progressive overall osteoarthritic changes in this aging population. Radiological evaluation showed maintenance of achieved alignment which did not deteriorate over time. Complication rate was low and did not require any further surgical interventions and did not have any effect on final good clinical outcome. CONCLUSION: Balloon kyphoplasty proved to be safe surgical technique and should be considered in patients with ongoing pain following an acute vertebral compression fracture that does not improve with initial conservative treatment. It significantly improves pain and functional status in elderly patients.

Coincident molecular auxeticity and negative order parameter in a liquid crystal elastomer.

Auxetic materials have negative Poisson's ratios and so expand rather than contract in one or several direction(s) perpendicular to applied extensions. The auxetics community has long sought synthetic molecular auxetics - non-porous, inherently auxetic materials which are simple to fabricate and avoid porosity-related weakening. Here, we report, synthetic molecular auxeticity for a non-porous liquid crystal elastomer. For strains above ~0.8 applied perpendicular to the liquid crystal director, the liquid crystal elastomer becomes auxetic with the maximum negative Poisson's ratio measured to date being -0.74 ± 0.03 - larger than most values seen in naturally occurring molecular auxetics. The emergence of auxeticity coincides with the liquid crystal elastomer backbone adopting a negative order parameter, QB = -0.41 ± 0.01 - further implying negative liquid crystal ordering. The reported behaviours consistently agree with theoretical predictions from Warner and Terentjev liquid crystal elastomer theory. Our results open the door for the design of synthetic molecular auxetics.

Missed cervical spine injuries: a national survey of the practice of evaluation of the cervical spine in confused and comatose patients.

AIM: Identifying cervical spine injuries in confused or comatose patients with multiple injuries provides a diagnostic challenge. Our aim was to investigate the protocols which are used for the clearance of the cervical spine in these patients in English hospitals. PATIENTS AND METHODS: All hospitals in England with an Emergency Department were asked about the protocols which they use for assessing the cervical spine. All 22 Major Trauma Centres (MTCs) and 141 of 156 non-MTCs responded (response rate 91.5%). RESULTS: Written guidelines were used in 138 hospitals (85%). CT scanning was the first-line investigation in 122 (75%). A normal CT scan was sufficient to clear the cervical spine in 73 (45%). However, 40 (25%) would continue precautions until the patient regained full consciousness. MRI was performed in all confused or comatose patients with a possible cervical spinal injury in 15 (9%). There were variations in the grade and speciality of the clinician who had responsibility for deciding when to discontinue precautions. A total of 31 (19%) reported at least one missed cervical spinal injury following discontinuation of spinal precautions within the last five years. Only 93 (57%) had a formal mechanism for reviewing missed injuries. TAKE HOME MESSAGE: There are significant variations in protocols and practices for the clearance of the cervical spine in multiply injured patients in acute hospitals in England. The establishment of trauma networks should be taken as an opportunity to further standardise trauma care. Cite this article: Bone Joint J 2016;98-B:825-8.

Rat colonic mucosal cell sialic acid metabolism in azoxymethane-induced tumours.

Colonic tissue was examined from normal (control) rats and azoxymethane- (carcinogen-) treated animals. Tumour-bearing colons from azoxymethane-treated rats were divided into malignant and non-malignant areas. Mucosal cells were prepared from the three types of colonic tissue and then examined for DNA and protein content and for the activities of ten enzymes involved in sialic acid metabolism. Enzyme activities were related to either the protein or the DNA content of fractions. The DNA content of cell homogenates was significantly different between tumour and non-malignant tissue and between both these tissues and normal mucosa. The protein content of the 100000 X g membrane pellet and supernatant fraction did not vary significantly between normal and non-malignant material but both these tissues differed significantly from tumour tissue. Significant variation between normal control and tumour tissue was detected at all levels of sialic acid metabolism, including N-acetylhexosamine interconversion and phosphorylation, sialic acid formation and activation, CMP-NeuAc breakdown and transfer and sialic acid release from glycoconjugates. The results indicate that major changes at all levels of sialic acid metabolism are associated with malignancy in rat colonic mucosa. Some of these changes are apparent in non-malignant mucosa and may reflect a pre-malignant state.

C-reactive protein and serum amyloid P component in the plaice (Pleuronectes platessa L.), a marine teleost, are homologous with their human counterparts.

C-reactive protein and serum amyloid P component were isolated from serum of the plaice (Pleuronectes platessa L.), a murine teleost. The isolation was based on their calcium-dependent binding affinity for pneumococcal C-polysaccharide and for agarose, respectively. These specificities are the same as those of human C-reactive protein and serum amyloid P component, respectively, and we have previously reported that the plaice molecules resemble human C-reactive protein and serum amyloid P component in their electron microscopic appearance. We describe here estimation of the molecular weights of plaice C-reactive protein and serum amyloid P component and their subunits, and analysis of their amino acid composition, glycosylation and partial amino-terminal amino acid sequences. The results establish that plaice C-reactive protein and serum amyloid P component are homologous with each other and with their human counterparts and indicate that there has been stable conservation of this protein family throughout vertebrate evolution.

The glycoconjugate content of human faeces and ileostomy effluents.

Normal human faeces and effluent from terminal ileostomies in patients with ulcerative colitis were collected. The results for ileostomy effluent given as g/24 h (mean +/- SD; n = 12) were as follows: wet weight, 897 +/- 120; total dry weight, 84 +/- 8; non-diffusible dry weight 46 +/- 5. The corresponding results for faeces (n = 6) were 104 +/- 24; 26 +/- 6; 19 +/- 5. Whereas approximately 15% of the total dry weight of ileostomy effluent appeared to consist of mucin-derived material, only trace amounts of such material could be detected in faeces.

Some aspects of the glycoprotein and glycopolypeptide content of human gastric mucus.

The carbohydrate content of non-diffusable, glycoprotein and glycopolypeptide material has been studied in normal human gastric aspirates. Pentagastrin doubles the volume of secretions but has no effect on the amount of non-diffusable material. Only about 40% of the weight of the non-diffusable material is mucin in nature. Gel-permeation chromatography indicated that about half of the mucin survived as high molecular mass glycoprotein. Monosaccharide differences, for example between secretors and non-secretors, only became manifest at the glycopolypeptide stage. These results emphasize the dangers of attempting to assess mucin changes by simple carbohydrate analyses of unfractionated gastric aspirates.

The nature of gastric secretions in a patient with Zollinger-Ellison syndrome without peptic ulceration.

A study has been made of the gastric secretions from a patient with Zollinger-Ellison syndrome without peptic ulceration, before and after treatment with cimetidine. The amount of non-diffusable glycoconjugates was measured as an index of mucin output, and found to be within normal limits. Cimetidine, which greatly reduced the volume of secretions, had no effect on the non-diffusable glycoconjugates. These results may explain the absence of peptic ulceration in certain patients with this syndrome.

The glycoprotein content of meconium.

Meconium pooled according to blood group activity has been studied. It was found to consists largely of glycoproteins. Two glycoprotein fractions have been isolated, one of which consisted of mucous-type glycoproteins and the other of "mannose-containing" glycoproteins.

Analysis of regurgitant jets in natural and bio-prosthetic heart valves.

Artificial bio-prosthetic heart valves are prone to fatigue tearing, having a 50% failure rate in ten years. Tears in valves give rise to pulsing reverse flow back through the valve. This is termed regurgitant flow and the resultant jet of blood a regurgitant jet. The regurgitant volume of the jet during the pulsing cycle gives a measure of the severity of the valve defect and clinical significance. Hence, it is important for the cardiologists to be able to quantify this volume. Although the velocity of the regurgitant jet can be determined using Doppler ultrasound, the dimensions of the heart valve lesion cannot be measured directly; hence, the volumetric flow rate cannot be quantified accurately. At present the severity of the regurgitant jet is assessed qualitatively from the intrusion of the jet into the cardiac chamber. In the present study, classical mathematical theories of turbulent jets have been used to describe the velocity distributions for the types of jets expected in defective heart valves and these distributions have been verified experimentally. One of these models has been developed to enable the regurgitant volumetric flow through an axisymmetric orifice of unknown radius to be calculated from the velocity distribution of the jet. This relationship may be used in conjunction with ultrasound techniques to quantify the regurgitant volume within defective artificial heart valve implants. The present study shows that there is a significant difference in the velocity distributions in jets emanating from axisymmetric and high aspect ratio slots.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of the results of sequential hydrazinolysis-nitrosation and alkali-mediated cleavage-nitrosation of the O-linked oligosaccharides of gastric mucus glycoproteins.

Analysis of the oligosaccharides released from pig gastric mucus glycopolypeptides by hydrazinolysis showed that degradation had occurred. Nitrosation of the products followed by reduction gave a mixture that had a low content of 2,5-anhydro-D-talitol, which implied destruction of much of the terminal reducing 2-amino-2-deoxy-D-galactose. Under the conditions of hydrazinolysis, cellobiose was largely unchanged but laminaribiose gave a complex mixture that probably contained glucose hydrazone (13C-n.m.r. data). In order to avoid degradation, the hydrazinolysis-nitrosation sequence should be applied to the reduced oligosaccharides released on cleavage with alkali.

The gastric mucosal barrier.

The gastric mucosal barrier is a complex system made up of submucosal, epithelial and mucus elements. The mucus gel layer is a thick tenacious organized layer adherent to the epithelium. Despite these properties it is composed of more than 95% water, the organization being provided by long interacting glycoprotein molecules (mucus glycoprotein or mucin). These molecules are largely made up of carbohydrate which is present in large numbers of relatively small oligosaccharide units packed around the polypeptide core. This structure provides clues to the nature of the protection afforded by the mucus layer. For example, it is relatively resistant to proteolysis in the gastrointestinal tract; it retains water in an unstirred layer; the tangled glycoproteins exclude large molecules and the carbohydrate of the oligosaccharide units mirror that at the surface of the epithelial cell. Few biochemical studies have been carried out on the effect of ulcer-healing drugs on gastric mucus. Normal subjects were, therefore, given two weeks treatment with cimetidine, carbenoxolone or misoprostol and the secretions aspirated from the unstimulated and pentagastrin-stimulated stomach. The volume of secretion and weight and carbohydrate content of non-diffusable glycoconjugates were determined for each specimen, together with the proportion of high molecular mass mucin and qualitative and quantitative analyses of the glycopolypeptide. There were no significant differences between the results for each drug or without drug. This may be because normal subjects were studied who already have an effective mucosal barrier. In addition, it is likely that the process of mucus biosynthesis and secretion in a healthy individual is relatively resistant to the action of ulcer healing drugs.

Measurement of sialyl-transferase activity in isolated colonic mucosal cells of the rat.

An assay for sialyl-transferase activity in isolated rat colonic mucosal cells has been developed. Total and specific activity with asialobovine sub-mandibular gland glycoprotein and endogenous substrates was approximately two-fold higher in the proximal, relative to the distal, colon. These activities were similar when asialo-alpha-acid glycoprotein was used as substrate. Endogenous activity was approximately 10-fold lower than with exogenous substrates in both proximal and distal colonic segments. Analysis of total and specific sialyl-transferase activity up to 7 weeks after jejunoileal bypass (JIB) and sham operation showed a marked increase at the first week, decreasing toward normal by week 7. Similar differences between proximal and distal colon, and with the type of substrate, were found with both groups of operated animals. Histochemical analysis showed small elevation after 1 week for sialo and sulphomucins after the JIB operation only.