scholarly journals Bony callus stiffness indirectly evaluated by the axial load-share ratio in vivo as a guide to removing a monolateral external fixator safely

2021 ◽  
Author(s):  
Yanshi Liu ◽  
Feiyu Cai ◽  
Kai Liu ◽  
Xingpeng Zhang ◽  
Hong Li ◽  
...  
Keyword(s):  
External Fixator ◽  
Axial Load ◽  
Mechanical Test ◽  
Statistical Significance ◽  
Radiological Assessment ◽  
Group I ◽  
Bony Callus ◽  
Group Ii ◽  
Monolateral External Fixator

Abstract Purpose As the monolateral external fixator is increasingly used in trauma-control and definitive management for high-energy long bone fractures, timing the fixator removal remains a challenge for surgeons. The purpose of this study was to determine the feasibility and effectiveness of the bony callus stiffness indirectly evaluated by the axial load-share ratio in vivo as a guide to removing a monolateral external fixator safely. Methods A total of 131 patients with tibial shaft fractures treated by the monolateral external fixator in our institution were collected from January 2013 to July 2019. In group I, the fixators were removed based on the clinical and radiological assessment only by the treating surgeon. As for group II, the axial load-share (LS) ratio test was accomplished by another medical team without the knowledge of the clinical results. The external fixator was removed when the mechanical test outcome (LS ratio < 10%) was consistent with the conclusion drawn from the clinical and radiological assessment (bone union achieved) by the treating surgeon. Results There was no statistical significance in demographic data between the two groups (P > 0.05). In group I, four patients suffered refracture (the refracture rate was 7.7%) after fixator removal and were successfully treated by an intramedullary nail. In group II, 71 patients underwent fixator removal after the first mechanical test, and another eight patients terminated the external fixation after the second test. None of the 79 patients in group II suffered refracture (the refracture rate was 0%). There was statistical significance in the refracture rate between the two groups (P < 0.05). Conclusion The bony callus stiffness indirectly evaluated by the axial load-share ratio in vivo using the additional circular frame components is an effectively quantitative indicator to complement the clinical assessment of fracture healing in a monolateral external fixation treatment. Removal of the monolateral external fixator is safe when the axial load-share ratio dropped below 10%.

scholarly journals The axial load-share ratio in vivo as a supplemental assessment for the external fixator safe removal

2021 ◽  
Author(s):  
Yanshi Liu ◽  
Qiyu Jia ◽  
Feiyu Cai ◽  
Kai Liu ◽  
Xingpeng Zhang ◽  
...  
Keyword(s):  
External Fixation ◽  
Clinical Experience ◽  
External Fixator ◽  
Axial Load ◽  
Mechanical Test ◽  
Statistical Significance ◽  
Demographic Data ◽  
Ratio Test ◽  
Ilizarov External Fixator

Abstract Background: Timing the fixator removal is vital for a successful external fixation treatment. The purpose of this study was to determine the effectiveness of axial load-share ratio in vivo as a supplemental decision support tool for the safe removal of an Ilizarov external fixator.Methods: This prospective observational study consists of 83 patients undergoing tibial or femoral lengthening with Ilizarov circular external fixation in our institution, from January 2011 to October 2019. In group Ⅰ (38 patients), the external fixator was removed based on the surgeon’s clinical experience and radiographs from January 2011 to June 2015. In group Ⅱ (45 patients), from July 2015 to October 2019, the supplemental axial load-share (LS) ratio test was accomplished without the knowledge of the clinical results by another medical team. When the LS ratio < 10% was consistent with the conclusion (dense bone formation was achieved in the distraction zone) drawn from the corresponding routine radiographs by the treating surgeon, the external fixator was removed.Results: There was no statistical significance in demographic data between the two groups (P>0.05). In group Ⅰ, 4 of the 38 patients suffered refracture (the refracture rate was 10.5%) after fixator removal, and bone union was finally achieved with further intervention by intramedullary nail. In group Ⅱ, 36 patients terminated the external fixation after the first mechanical test, and another 9 patients terminated the external fixation at the subsequent test. None of the 45 patients in group Ⅱ suffered refracture (the refracture rate was 0%). There was statistical significance in the refracture rate between the two groups (P<0.05).Conclusions: Adequate assessment of bone regenerate is crucial before removing an external fixator to prevent deformation or refracture. The axial load-share ratio in vivo is a practically quantitative method to supplement radiography and clinical experience for the assessment of regenerate healing, and the axial load-share ratio dropped below 10% is a safe limit for the Ilizarov external fixator removal.

scholarly journals The Axial Load-Share Ratio in Vivo as a Supplemental Assessment for the External Fixator Safe Removal

2021 ◽  
Author(s):  
Yanshi Liu ◽  
Qiyu Jia ◽  
Feiyu Cai ◽  
Kai Liu ◽  
Tao Zhang ◽  
...  
Keyword(s):  
External Fixation ◽  
Clinical Experience ◽  
External Fixator ◽  
Axial Load ◽  
Mechanical Test ◽  
Statistical Significance ◽  
Demographic Data ◽  
Ratio Test ◽  
Ilizarov External Fixator

Abstract Background: Timing the fixator removal is vital for a successful external fixation treatment. The purpose of this study was to determine the effectiveness of axial load-share ratio in vivo as a supplemental decision support tool for the safe removal of an Ilizarov external fixator.Methods: This prospective observational study consists of 83 patients undergoing tibial or femoral lengthening with Ilizarov circular external fixation in our institution, from January 2011 to October 2019. In group Ⅰ (38 patients), the external fixator was removed based on the surgeon’s clinical experience and radiographs from January 2011 to June 2015. In group Ⅱ (45 patients), from July 2015 to October 2019, the supplemental axial load-share (LS) ratio test was accomplished without the knowledge of the clinical results by another medical team. The test was performed by electronically measuring forces in the fixator rods and in a ground force plate. When the LS ratio < 10% was consistent with the conclusion (dense bone formation was achieved in the distraction zone) drawn from the corresponding routine radiographs by the treating surgeon, the external fixator was removed.Results: There was no statistical significance in demographic data between the two groups (P>0.05). In group Ⅰ, 4 of the 38 patients suffered refracture (the refracture rate was 10.5%) after fixator removal, and bone union was finally achieved with further intervention by intramedullary nail. In group Ⅱ, 36 patients terminated the external fixation after the first mechanical test, and another 9 patients terminated the external fixation at the subsequent test. None of the 45 patients in group Ⅱ suffered refracture (the refracture rate was 0%). There was statistical significance in the refracture rate between the two groups (P<0.05).Conclusions: Adequate assessment of bone regenerate is crucial before removing an external fixator to prevent deformation or refracture. The axial load-share ratio in vivo is a practically quantitative method to supplement radiography and clinical experience for the assessment of regenerate healing, and the axial load-share ratio dropped below 10% is a safe limit for the Ilizarov external fixator removal.

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović
Keyword(s):  
Radionuclide Ventriculography ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Volume Determination ◽  
Group I ◽  
Lv Volumes ◽  
Group Ii ◽  
Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

A P-Selectin/CD62P Monoclonal Antibody (LYP-20), in Tandem with Flow Cytometry, Detects in vivo Activated Circulating Rat Platelets in Severe Vascular Trauma

1994 ◽  
Vol 72 (05) ◽  
pp. 745-749 ◽  
Author(s):  
Elza Chignier ◽  
Maud Parise ◽  
Lilian McGregor ◽  
Caroline Delabre ◽  
Sylvie Faucompret ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Platelet Activation ◽  
Peripheral Blood ◽  
Vascular Trauma ◽  
Activated Platelets ◽  
Group I ◽  
Group Ii ◽  
Rat Platelets

SummaryP-selectin, also known as CD62P, GMP140 or PADGEM, is present in platelet a-granules and endothelial cell Weibel-Palade bodies and is very rapidly expressed on the surface of these cells on activation. In this study, an anti P-selectin monoclonal antibody (LYP20) was used, in tandem with flow cytometry, to identify activated platelets at the site of induced vascular trauma or in peripheral blood. Moreover, electron microscopy was performed to characterize sites of vascular trauma and quantify the number of adhering platelets. The same induced vascular trauma was observed to result into animals responding in 2 different ways (Group I, Group II) following the degree of platelet activation. Five rats, out of 14 with induced vascular trauma, had more than half of their circulating platelets expressing P-selectin when drawn at the site of the trauma (67.4% ± 3.44) or in peripheral blood (78.5% ± 2.5) (Group I). In the remaining 9 animals a much smaller proportion of circulating platelets expressed P-selectin when assayed from trauma sites (18% ± 3.34) or in peripheral blood (18.0% ± 4.30) (Group II). Enhanced P-selectin expression by circulating platelets in Group I, compared to Group II, appears to be linked to the degree of activated platelets adhering at sites of trauma (171 ± 15 × 103 platelets versus 48 ± 31 × 103 platelets per mm2). In the 5 control animals, that were not operated on, platelets expressing P-selectin when drawn at the site of a mock trauma (7.0% ± 1.84) or in the peripheral blood (11.2% ± 3.30) showed little activation. In addition, no platelet adhesion was seen on the vascular bed of these animals. Results from this study show that analysis of P-selectin (CD62P) expression, in circulating platelets, is a valuable and rapid marker of platelet activation following severe vascular trauma induced in rats. However, activated platelets were not detected to the same extent in the peripheral blood of all animals having undergone vascular trauma. It is conceivable that platelets, depending on the degree of activation, may be actively sequestered in organs and prevented from circulating. Alternatively, P-selectin may be rapidly endocytosed, or not expressed, by activated circulating platelets depending on the type of agonists implicated in vivo activation.

(Preprint)

2018 ◽  
Author(s):  
Dr Malathi Dayalan ◽  
Dr Sudeshna Sharma ◽  
Dr Shweta Poovani ◽  
Dr Saher Altaf
Keyword(s):  
Myofascial Pain ◽  
Mouth Opening ◽  
Masticatory Muscles ◽  
Matched Pair ◽  
Masticatory Muscle ◽  
Muscle Disorders ◽  
Occlusal Contact ◽  
Group I ◽  
Group Ii

BACKGROUND Masticatory system is a complex functional unit, primarily engaged in chewing, swallowing and breathing functions, and some parts are involved in taste recognition and determination of food consistency. Sophisticated functional performances of speech and emotional expressions are specifically human qualities. Irregularities in occlusion appears to be the precipitating factor in the pathogenesis of myofascial pain dysfunction syndrome. Tek- Scan III records the bite length, number, distribution, timing, duration and the relative force of each tooth contact. It also records the sequence of occlusal contacts in terms of time and the associated force with each occlusal contact. The aim of this study was to treat masticatory muscle disorders with occlusal equilibration, and compare the efficacy of treatment outcomes between selective grinding and stabilization splints using Tek-Scan III. OBJECTIVE Objective of this study was to compare the efficacy of occlusal equilibration achieved through selective griding and stabilization splints using Tek-Scan III. METHODS In this in vivo study, 40 patients with masticatory muscle disorders were selected based on the inclusion and exclusion criteria. The occlusal discrepancies were analyzed using Tek-Scan III. The selected 40 subjects were then randomly divided into 2 groups based on the treatment they recieved; Group I – Selective grinding group (20) and Group II – Stabilization splint group (20). Comparison of pre-treatment and post treatment results were evaluated in terms of pain, mouth opening, left and right side force percentage as recorded through Tek-Scan III and reduction of disclusion time. Statistical analysis was carried out with Kolmogorov Smirnov test, Wilcoxon matched pair test and Mann-Whitney U test. RESULTS Wilcoxon matched pairs test demonstrated that there was statistically significant results ( p = 0.0007) in both the groups for reduction of disclusion time, elimination of pain and improved mouth opening. Patients in Group I showed better results as compared to Group II in terms of disclusion time, pain and mouth opening. CONCLUSIONS Occlusal equilibration brought about by reducing the disclusion time using the Tek- Scan III reduced the symptoms of pain in masticatory muscles. Patients in group I (Selective grinding) however showed better results when compared to patients in group II (Stabilization splints).

Comparison of a PGA Sheet with a Commercial ePTFE Sheet as a Staple-Line Reinforcement in Lung Surgery

2007 ◽  
Vol 342-343 ◽  
pp. 849-852
Author(s):  
Keon Hyeon Jo ◽  
Seok Whan Moon ◽  
Young Du Kim ◽  
Young Jo Sa ◽  
Si Young Choi ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Polyglycolic Acid ◽  
Lung Surgery ◽  
Resection Margins ◽  
Air Leakage ◽  
Staple Line Reinforcement ◽  
Group I ◽  
Significant Difference ◽  
Similar Threshold ◽  
Group Ii

To prevent prolonged air leakage after lung surgery, we developed a biodegradable polyglycolic acid (PGA) sheet and compared it with an expanded polytetrafluoethylene (ePTFE). Eighteen adult mongrel dogs were used in this experiment. The airway pressures at which air first leaked at the stapled resection margins were measured immediately after surgery in group I (N=5), 2 days after surgery in group II (N=5), and 7 days after surgery in group IIII (N=5), Based on the presence of SLR, there were 3 subgroups in each group: there was no SLR in subgroup a; ePTFE in subgroup b; PGA sheet in subgroup c. The histologic examination was performed 2 months after surgery (N=3). In group I, there was a significant difference in air leakage pressures (mm Hg) between no reinforcement and SLR. We observed the same results in group II and III with statistical significance. However, there was no significant difference between the reinforcement groups. The histologic findings demonstrated more severe adhesions and biodegradation in the dogs in which the PGA sheet was used. Our PGA sheet was considered a useful reinforcement material, because it had a similar threshold for air leakage with the ePTFE with excellent biodegradation.

Ventilation and thoracoabdominal asynchrony during halothane anesthesia in infants

1993 ◽  
Vol 74 (4) ◽  
pp. 1591-1596 ◽  
Author(s):  
M. Benameur ◽  
M. D. Goldman ◽  
C. Ecoffey ◽  
C. Gaultier
Keyword(s):  
Tidal Volume ◽  
Minute Ventilation ◽  
Statistical Significance ◽  
Age Group ◽  
Halothane Anesthesia ◽  
Minimal Alveolar Concentration ◽  
Group I ◽  
Wall Compliance ◽  
Group Ii ◽  
Thoracoabdominal Asynchrony

To evaluate the ventilatory consequences of high chest wall compliance during anesthesia in infants, we assessed the effects of halothane at different fractions of minimal alveolar concentration (0.75, 1.0, and 1.5 MAC) on ventilation and movements of the rib cage and abdomen in infants < or = 12 mo of age (group I) and children (group II) > or = 12 mo of age. Minute ventilation decreased in group I, (20.6%, 0.75 to 1.5 MAC), but the change in group II did not reach the level of statistical significance. Tidal volume decreased with halothane level between 0.75 and 1.5 MAC, and its fall was greater in group I (32.7 +/- 11.2 vs. 22.6 +/- 9.3% in group II, P < 0.05). Duty cycle, or ratio of inspiratory to total time (TI/TT), increased in group II with halothane level but did not change in group I, resulting in a decreased TI in group I at higher halothane levels. Thoracic paradox increased with halothane level in group I but not group II. The increase in thoracic paradox in association with the fall in tidal volume between 0.75 and 1.5 MAC was greater in group I than group II (P < 0.05). We conclude that smaller infants depend more on inspiratory intercostal muscle activity to stabilize the thorax, leading to a greater degree of depression of ventilation during halothane depression of inspiratory intercostal activity.

Correlation of blood rheology with vascular resistance in critically ill patients

1975 ◽  
Vol 39 (6) ◽  
pp. 1008-1011 ◽  
Author(s):  
P. M. Scholz ◽  
J. H. Karis ◽  
F. E. Gump ◽  
J. M. Kinney ◽  
S. Chien
Keyword(s):  
Critically Ill ◽  
Blood Viscosity ◽  
Critically Ill Patients ◽  
Peripheral Resistance ◽  
Plasma Viscosity ◽  
Low Flow ◽  
Red Cell Deformability ◽  
Group I ◽  
Group Ii

Blood rheologic measurements together with peripheral resistance determinations in vivo were made in 27 critically ill patients. Eighteen of these patients (group I) suffered from violent trauma or operative injury and the other 9 (group II) were patients with generalized sepsis. As a result of fluid therapy all patients underwent hemodilution, resulting in a decrease in blood viscosity. This drop in blood viscosity was counteracted to some extent by an increased plasma viscosity due to elevated fibrinogen levels and a decreased red cell deformability associated with massive transfusions of stored blood. The correlation of vivo hemodynamics with blood rheological data made it possible to separate the relative roles of vascular dimensions and blood viscosity in affecting the total peripheral resistance. This approach permitted us to distinguish varying degrees of vasoconstriction in nonseptic patients in low flow states (group I) and varying degrees of vasodilation in septic patients (group II). This type of analysis serves to elucidate the pathophysiology of hemodynamic alterations in disease and provides a rational basis for devising an effective therapeutic program.

scholarly journals Differential Abilities of Capsulated and Noncapsulated Staphylococcus aureus Isolates from Diverse agr Groups To Invade Mammary Epithelial Cells

2006 ◽  
Vol 75 (2) ◽  
pp. 886-891 ◽  
Author(s):  
Fernanda R. Buzzola ◽  
Lucía P. Alvarez ◽  
Lorena P. N. Tuchscherr ◽  
María S. Barbagelata ◽  
Santiago M. Lattar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Pcr Amplification ◽  
Variable Region ◽  
Polymorphism Analysis ◽  
Accessory Gene ◽  
Group I ◽  
Group Ii

ABSTRACT Staphylococcus aureus is the bacterium most frequently isolated from milk of bovines with mastitis. Four allelic groups, which interfere with the regulatory activities among the different groups, have been identified in the accessory gene regulator (agr) system. The aim of this study was to ascertain the prevalence of the different agr groups in capsulated and noncapsulated S. aureus bacteria isolated from mastitic bovines in Argentina and whether a given agr group was associated with MAC-T cell invasion and in vivo persistence. Eighty-eight percent of the bovine S. aureus strains were classified in agr group I. The remainder belonged in agr groups II, III, and IV (2, 8, and 2%, respectively). By restriction fragment length polymorphism analysis after PCR amplification of the agr locus variable region, six agr restriction types were identified. All agr group I strains presented a unique allele (A/1), whereas strains from groups II, III, and IV exhibited more diversity. Bovine S. aureus strains defined as being in agr group I (capsulated or noncapsulated) showed significantly increased abilities to be internalized within MAC-T cells, compared with isolates from agr groups II, III, and IV. agr group II or IV S. aureus strains were cleared more efficiently than agr group I strains from the murine mammary gland. The results suggest that agr group I S. aureus strains are more efficiently internalized within epithelial cells and can persist in higher numbers in mammary gland tissue than S. aureus strains classified in agr group II, III, or IV.

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