Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Fixatives”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed2000

The pelvic external fixation: the mid-term results of 41 patients treated with a newly designed fixator.

The purpose of this study was to evaluate the clinical and radiological results of unstable pelvic fractures treated with a new external fixation device. Between May 1992 and May 1998, 43 patients with unstable pelvic fractures were treated with a new anterior pelvic external fixator. Two died, and therefore 41 patients' results were evaluated. There were 29 men and 12 women, and their average age was 34 years (range 12-70 years). Traffic accidents accounted for 34 injuries. Three patients fell from a height, 3 were injured in industrial accidents, and 1 was hit by a train. According to the Tile classification, there were 24 type B pelvic injuries and 17 type C. Associated injuries were observed in 21 patients. A considerable reduction of the pelvic pain was noted after application of the fixator in all patients. Excessive blood transfusion was not required in any patient. The average follow-up was 24 months (range 12-50 months). Clinical results at final evaluation were good according to the criteria of Matta and Saucedo in 34 patients and poor in 7. In conclusion, the new pelvic external fixator is effective, safe, and easy to apply in the treatment of unstable pelvic fractures. The fixator can be used alone in patients with type B pelvic injuries such as open book and lateral compression. However, it does not provide sufficient stability for severely displaced type C injuries when applied alone. Nevertheless, it may be helpful for fixing type C injuries like a posterior iliac fracture without dislocation of the sacroiliac joint.

Adolescent↗
PubMed2005

Dorsal fracture-dislocation of the proximal interphalangeal joint: a comparative study of percutaneous Kirschner wire fixation versus open reduction and internal fixation.

Nineteen patients with a dorsal fracture-dislocation of the proximal interphalangeal joint of a finger were treated with either closed reduction and transarticular Kirschner wire fixation (eight cases) or open reduction and internal fixation, using either one or two lag screws (six cases) or a cerclage wire (five cases). At a mean follow-up of 7 (range 6-9) years, most patients reported satisfactory finger function, even though some of the injuries healed with proximal interphalangeal joint incongruency (seven cases) or subluxation (four cases). Those treated by open reduction complained of more "loss of feeling" in the affected finger and those specifically treated by cerclage wire fixation reported more cold intolerance and had a significantly larger fixed flexion deformity (median, 30 degrees : range 18-38 degrees ) and a smaller arc of motion (median, 48 degrees : range 45-60 degrees ) at the proximal interphalangeal joint, despite having the best radiological outcomes. Closed reduction and transarticular Kirschner wire fixation produced satisfactory results, with none of the eight patients experiencing significant persistent symptoms despite a reduced arc of proximal interphalangeal joint flexion (median=75 degrees ; range 60-108 degrees ). The results of this relatively simple treatment appear at least as satisfactory as those obtained by the two techniques of open reduction and internal fixation, both of which were technically demanding.

Adult↗
PubMed2005

The need for intermaxillary fixation in sagittal split osteotomy setbacks with bicortical screw fixation.

OBJECTIVE: The aim of this study was to decide whether use of bicortical screw fixation provides sufficient stability to dispense with intermaxillary fixation (IMF). STUDY DESIGN: Eighty-six patients who had undergone surgical setback of the mandible using bilateral sagittal split ramus osteotomies were examined. Group 1 (15 patients) received miniplate fixation with IMF for 6 weeks, and group 2 (71 patients) received bicortical screw fixation and immediate postoperative function. The 2 groups were evaluated radiographically for postsurgical changes of the pogonion 24 months postoperatively. RESULTS: There was no significant difference in the magnitude of the relapse between the 2 groups over the 24-month postoperative period. CONCLUSION: The use of bicortical screw fixation after sagittal split setback of the mandible provides sufficient stability to dispense with IMF.

Adolescent↗
PubMed1999

Integrated effect of stimulation at fixation points on EFRP (eye-fixation related brain potentials).

The purpose of this study was to investigate the integrated effect of stimulation at the fixation points just before and just after saccadic eye-movement (saccade) on eye-fixation related brain potentials (EFRP: P75 and N105). Checkerboard patterns were used as stimuli. In Experiment 1, changes in check sizes between two fixation points enhanced the amplitude of P75, while changes in the phases of patterns between the two points did not affect EFRP. This result showed that EFRP was affected by two fixation points, and that changes in the retinal image between the two points did not necessarily affect EFRP. In Experiment 2, the relationship between EFRP and check size was investigated in detail. A second order relationship between logarithm of check size and the latency of P75, and a linear relationship between logarithm of check size and the amplitude of N105 were found. The effect of check size on the amplitude of P75 which might explain the increased amplitude of P75 observed in Experiment 1 did not appear. These results suggest that EFRP might reflect relative higher processing than peripheral stimulation at one fixation point.

Adolescent↗
PubMed2000

Bilateral sagittal split osteotomy and temporomandibular disorders: rigid fixation versus wire fixation.

OBJECTIVE: The effects of orthognathic surgery on temporomandibular disorders may be related to the surgical method that is used. Specifically, it has been suggested that the choice of stabilization technique may play a major role in the functional outcome of mandibular advancement surgery. The purpose of this study was to prospectively compare long-term (2 years) signs and symptoms of temporomandibular disorders after orthognathic surgery with bilateral sagittal split osteotomy in 127 patients randomized to receive rigid or wire fixation. STUDY DESIGN: Signs and symptoms of temporomandibular disorders were evaluated before and 2 years after surgery by means of the overall craniomandibular index (CMI), dysfunction index (DI), and muscle index (MI). Patients also reported subjective symptoms of temporomandibular disorders by marking areas of pain on a standard drawing of the head and rating the pain in each area on a scale ranging from 1 (very mild) to 7 (very extreme). Subjective pain was also assessed through use of the Oral Health Status Questionnaire and by a rating of the difficulty in opening the mouth because of pain. RESULTS: There were no statistically significant differences in the CMI, MI, or DI change scores between the wire and rigid fixation groups (mean CMI(wire) = 0.05, mean CMI(rigid) = 0.04; mean DI(wire) = 0.02, mean DI(rigid) = 0. 01; mean MI(wire) = 0.08, mean MI(rigid) = 0.08) 2 years after surgery. Temporomandibular joint sounds also demonstrated no significant differences between the two fixation methods. Subjective pain reports were consistent with the clinical examinations. On average, both wire and rigid scores decreased slightly, but the change scores were not significantly different between groups. CONCLUSIONS: These findings suggest that the long-term (2 years) effects of wire and rigid internal fixation methods on the signs and symptoms of temporomandibular disorders do not differ. Earlier concerns about increased risk for temporomandibular disorders with rigid fixation were not supported by these results.

Adult↗
PubMed1991

Effects of various fixatives and fixation conditions on DNA ploidy analysis. A need for strict internal DNA standards.

DNA ploidy and cell cycle analyses are being used with increasing frequency as additional, sometimes independent, biologic prognosticators of various malignancies. For obvious reasons, most of the large studies published are retrospective, using archival paraffin-embedded tissues likely to have been fixed and processed differently. To assess the effect of various fixation conditions on ploidy analyses, the authors performed a comprehensive study in which five contiguous aliquots from 26 tissue samples were fixed in formalin for 8. 24, and 48 hours; B5; and the ethanol-based fixative Omnifix (Omni, Xenetics Biomed Inc., Irvine, CA), respectively. The samples were prepared and stained with the use of Hedley's method; the DNA analyses were done with a Coulter EPICS V flow cytometer (Coulter Electronics, Hialeah, FL); and the resulting histograms were interpreted with Multicycle software (Phoenix Flow Systems, San Diego, CA). Mean channels and coefficients of variation (CVs) of the G0/G1 peaks were compared. Increasing fixation times in formalin produced slight shifting to the left on the G0/G1 peaks with differences up to 13 channels. Omni caused similar but more conspicuous changes, with maximal shifting of 51 channels. B5 created the opposite effect, with right-shifted G0/G1 peaks up to 22 channels. The CVs deteriorated progressively with increasing fixation times in formalin. B5 and Omni fixatives conferred the worse histograms, with 6 and 15 cases, respectively, displaying CVs greater than 8. Such significant differences preclude the use of any other internal standard but adjacent normal tissue that was processed exactly the same as the tumor. The validity of DNA results obtained otherwise should be considered questionable. These findings may explain some of the previously published controversial reports and emphasize the need to use an internal standard and more stringent criteria to define aneuploidy in paraffin-embedded tissue.

Cell Cycle↗
PubMed2002

Open reduction and internal fixation of unstable distal radius fractures: results using the trimed fixation system.

OBJECTIVE: The purpose of this study was to evaluate the early results of patients with displaced and unstable distal radius fractures treated with fragment-specific fixation. DESIGN Prospective and consecutive. SETTING: Private orthopaedic practice. PATIENTS/PARTICIPANTS: Twenty-five patients with 27 fractures with an average follow-up of 29 months (range 24-36 months) treated with fragment-specific fixation for unstable radius fractures. MAIN OUTCOME MEASUREMENTS: Clinical and radiographic examination. Disabilities of the arm, hand, and shoulder and patient-rated wrist evaluation outcome measures. RESULTS Patients had an average 61 degrees of dorsiflexion and 54 degrees of palmarflexion at the wrist. Twenty-five fractures healed in acceptable alignment, with one loss of reduction and one patient death. Mean +/- standard deviation DASH score was 17 +/- 18, and PRWE score was 19 +/- 22. CONCLUSION: Unstable distal radius fractures can be reliably and anatomically reduced and stabilized using fragment-specific fixation. Fixation of markedly comminuted fractures is secure enough to allow immediate motion and does not require casting or external fixation. Preliminary clinical and radiographic results are excellent, and patient satisfaction is high. Anatomic reduction with early motion can be achieved in a routine fashion on unstable distal radius fractures using the described technique.

Adult↗
PubMed2004

Tricortical versus quadricortical syndesmosis fixation in ankle fractures: a prospective, randomized study comparing two methods of syndesmosis fixation.

OBJECTIVE: To assess short-term functional results in 2 types of syn-desmotic fixation, comparing the traditional rigid quadricortical syndesmotic screw fixation with a more dynamic tricortical screw fixation. DESIGN: : Prospective, randomized clinical study. SETTING: University clinic, level 1 trauma center. PATIENTS: Sixty-four patients with closed ankle fractures in which the syndesmosis was found to be unstable intraoperatively. INTERVENTION: The unstable syndesmoses were fixed with either one 4.5-mm cortical screw through both tibial cortices (n = 30) or two 3.5-mm cortical screws engaging only 1 cortex of the tibia (n = 34). The quadricortical screws were routinely removed after 2 months, whereas the tricortical screws were removed only in the case of discomfort. Rehabilitation was the same in both groups. RESULTS: The Olerud Molander functional score (0-100) was significantly higher in the tricortical group (77 points) compared with the quadricortical group (66 points) (P = 0.025) at 3 months. After 1 year, however, the functional score was not significantly higher (P = 0.192) in the tricortical group (92.6 points) compared with the quadricortical group (85.7 points). Pain was significantly lower in the tricortical group (P = 0.017) after 3 months, but there was no significant difference after 1 year. There was no significant difference in dorsiflexion between the groups at any point of time. No losses of fixation were detected. The tricortical screws were removed in 2 patients due to migration. CONCLUSIONS: Syndesmosis fixation with 2 tricortical screws is safe and improves early function. After 1 year, however, there were no significant differences between the 2 groups in functional score, pain, and dorsiflexion.

Adolescent↗
PubMedDate not supplied

The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part I: femoral site.

BACKGROUND: Strength of graft fixation is the weakest link in anterior cruciate ligament reconstruction. HYPOTHESIS: There is no difference in initial fixation strength between different hamstring tendon graft femoral fixation devices. STUDY DESIGN: Randomized experimental study. METHODS: Each of six devices was used in the fixation of 10 quadrupled human semitendinosus-gracilis tendon grafts in tunnels drilled in porcine femora and tested 10 times with a single-cycle load-to-failure test at a rate of 50 mm/min and 10 times with a 1500-cycle loading test between 50 and 200 N at one cycle every 2 seconds. The specimens that survived the cyclic loading were subjected to a single-cycle load-to-failure test. RESULTS: The Bone Mulch Screw (1112 N) was strongest in the single-cycle load-to-failure test, followed by EndoButton CL (1086 N), RigidFix (868 N), SmartScrew ACL (794 N), BioScrew (589 N), and RCI screw (546 N). It also showed the lowest residual displacement (2.2 mm) and was strongest in the single-cycle load-to-failure test after cyclic loading. CONCLUSIONS: The Bone Mulch Screw was superior to all other devices. CLINICAL RELEVANCE: Caution may be warranted in employing aggressive rehabilitation after reconstruction with these devices. Preconditioning of the graft-implant complex before fixation is important.

Analysis of Variance↗
PubMed2006

Syndesmosis fixation: a comparison of three and four cortices of screw fixation without hardware removal.

BACKGROUND: Great variability exists in methods of stabilization for syndesmotic disruptions of the ankle. We hypothesized that syndesmotic screw fixation with 3.5-mm fully threaded cortical screws through either three or four cortices would have similar strength and rate of mechanical failure and that retention of screws after fracture healing would not result in adverse clinical symptoms. METHODS: In a prospective, surgeon-randomized study at a Level-one trauma center, 127 patients with syndesmotic disruptions were treated surgically. Seven patients were lost to followup, leaving 120 for review. Syndesmotic disruptions were stabilized with 3.5-mm fully threaded cortical screws placed through three or four cortices. Screws were removed only if symptomatic. Outcome criteria were screw failure, loss of reduction, and need for hardware removal. RESULTS: Fifty-nine patients received fixation through three cortices and 61 patients received fixation through four cortices. Mean follow-up was 150 days. In the group with stabilization through three cortices, hardware failure occurred in five patients (8%) and three had a loss of reduction. In the group with stabilization through four cortices, hardware failure occurred in four patients (7%); all were asymptomatic and did not require screw removal. There was no loss of reduction in that group. Comparing the two groups using binary logistic analysis, there was no difference in loss of reduction (p = 0.871), screw breakage (p = 0.689), or need for hardware removal (p = 0.731). CONCLUSION: The data suggest that either three or four cortices of fixation can be used when stabilizing syndesmotic injuries of the ankle. There was a trend towards higher loss of reduction in the group with tricortical fixation when weightbearing restrictions were not followed. Retention of the syndesmotic screws, even with mechanical failure, does not pose a clinical problem. Weightbearing can be allowed at 6 to 10 weeks without routine removal of screws.

Adult↗
PubMed1986

The influence of protease digestion and duration of fixation on the immunostaining of keratins. A comparison of formalin and ethanol fixation.

The effect of three proteases--trypsin, pepsin, and pronase--on the immunohistochemical staining of keratins with a broad-spectrum monoclonal antibody was investigated in paraffin sections of formalin and ethanol-fixed tissues by means of the peroxidase-antiperoxidase method. Both the length of exposure to the fixative and the duration of proteolysis were varied over a wide range. Ethanol-fixed tissues showed excellent preservation of the antigenicity of keratins, and no appreciable differences in immunostaining related to the length of fixation were found. The use of proteolytic enzymes did not improve these results; on the contrary, it caused rapid tissue disintegration. Formalin-fixed epithelial tissues stained weakly or failed to stain unless they were treated with a proteolytic enzyme. The optimal length of proteolysis varied with the degree of fixation; tissues that were fixed for long periods of time in formalin required longer exposure to a proteolytic enzyme and were more resistant to digestion than were tissues that were fixed briefly. No significant advantage of one protease over another was found in this study. We conclude that a proteolytic step must precede immunostaining for keratins if the tissue is fixed in formalin, but that the digestion period must be adjusted according to the length of exposure to the fixative. The superiority of alcohol over formalin fixation for the preservation of the antigenicity of keratins is confirmed by this study.

Ethanol↗
PubMed2005

A simple way to model wires used in ring fixators: analysis of the wire stiffness effect on overall fixator stiffness.

The Ilizarov fixator has become widely used in the treatment of complex trauma and deformity correction in the United Kingdom over the last few decades. As such, it has been widely researched. Within this fixator, the characteristic fine wires are the weakest and most flexible component. The wires allow interfragmentary micromotion, which is believed to be beneficial to bone healing. In this paper, a novel and simple numerical model of the stiffness and deflection of the wires when the fixator is subject to axial and torsional loading is presented. A range of wire lengths and pretensions are analysed, and the results compared to the findings of other researchers, with generally good agreement. This indicates that fixator stiffness can be determined simply and without recourse to sophisticated finite element analyses or extensive physical testing. In addition, the model is used to predict the contribution of the wires to the overall stiffness of the fixator.

Animals↗
PubMed2002

[Tensile strength of bone fixation of hydroxyapatite coated Schanz screws of the Heidelberg External Fixation System (HEFS)--comparative torque measurements in clinical use and in cadaver tibia].

It is claimed in the literature that hydroxyapatite(HA)-coated screws of external fixators have superior fixation strength in bone, which is postulated to lead to a substantial decrease in loosening and infection rates. We report on a study of the maximum torque values developed while inserting and removing 30 HA-coated Schanz screws of 8 Heidelberg external fixation systems applied to the tibia to correct leg length differences and axial deformities. The infection rate was determined in accordance with defined criteria, and was found to be about 20% for the HA-coated screws. Screws without infection showed an extraction torque above insertion torque, screws with infection an extraction torque below. A significant correlation (p = 0.05) was seen between infection and decrease in fixation strength (quotient: loosening torque/tightening torque). To exclude the impact of such biological processes as osteointegration and bone remodelling, the clinical results were compared with the torques measured for coated and uncoated Schanz screws in a human cadaveric tibia. A significantly higher fixation strength in bone was found for HA-coated screws in comparison with uncoated screws (p = 0.002). These data warrant a clinical study directly comparing HA-coated and uncoated Schanz screws.

Bone Remodeling↗
PubMed1992

Short fixation-shock freezing and freeze-drying versus chemical fixation and dehydration: computer assisted image analysis of morphological variables and immunogold labeling density on pituitary secretory granules.

We have performed a computer assisted image analysis evaluation of the effects of two preparation protocols on morphological variables and immunolabeling density of secretory granules using rat adenohypophysis as a model. Glutaraldehyde (GA) fixation for 2 hr and chemical dehydration was compared with short GA fixation (15 min) followed by cryofixation and freeze-drying (CF-FD). The 2 hr GA fixed specimens showed spherical nuclei and secretory granules regardless of their size, contrasting with the more irregularly shaped nuclei and secretory granules after short GA-CF-FD. In the latter group of specimens a correlation could be found between smaller nuclear areas and more irregular shapes. The differences in morphological variables between the two preparation protocols might be due to a better protein stabilization and a reduced collapse of macromolecules after the 2 hr GA fixation, strengthened by the chemical dehydration. The specific immunolabeling with antiserum to growth hormone was much greater but more varied after short time GA-CF-FD than after long GA fixation. Epon surface topography over the granule area also differed: smooth after short time GA-CF-FD and furrowed after long GA fixation. Our results, demonstrating important differences in morphological parameters and immunolabeling density between two common preparation protocols, seem critical for more reliable interpretation in quantitative immunoelectron microscopy. We also emphasize the need for computer assisted image analysis and measurements in immunoelectron microscopy to ensure objective evaluations.

Animals↗
PubMed2002

[The results of plate fixation with the use of biological fixation principles and minimally invasive technique in femur fractures].

OBJECTIVES: We evaluated the clinical and radiologic results of patients treated by the minimally invasive technique and plate fixation in accordance with biological fixation principles for femoral fractures. METHODS: Biological fixation principles were used in the treatment of 24 patients (18 males, 6 females; mean age 32 years; range 18 to 56 years) with femoral fractures. Fractures were reduced by indirect reduction and the plate was forwarded through distal and proximal incisions over the periosteum without the need for incisions on the fracture line. Fixation of the plates was performed with the use of screws from distal and proximal incisions. The patients were allowed partial and full weight-bearing in a mean of 3.6 and 5 months, respectively. By means of monthly clinical and radiologic examinations, union was assessed by callus formation in the fracture line and painless weight-bearing. In addition, leg length discrepancy, rotation, angulation deformities, and knee and hip range of motions were determined. The mean follow-up was 2 years and 7 months (range 16 months to 4 years and 5 months). RESULTS: The mean union time was 4.6 months (range 4 to 11 months). Except for one patient (4%) with delayed union, all patients achieved union. No infections occurred related to the fracture site. CONCLUSION: Successful clinical and radiologic results can be obtained by biological methods of fixation in diaphyseal femur fractures with multiple fragments, segment formation, in multi-trauma patients with high Injury Severity Score and compromised pulmonary function, and in those having subtrochanteric or supracondylar fractures associated with high complication rates.

Adolescent↗
PubMed1988

The effects of fixative type and fixation time on the quantity and quality of extractable DNA for hybridization studies on lymphoid tissue.

Encouraged by recent reports of extraction of diagnostically useful DNA from formalin-fixed tissues, we devised a study to determine which fixatives are suitable for DNA hybridization studies. Seven lymph node specimens (6 lymphomas and one reactive hyperplasia) were studied. Specimens were divided into portions, each of which was processed separately. Processing protocols followed were: 1) snap freezing; 2) immersion in formalin, ethanol, glutaraldehyde, B5 and methanol acetic acid (MAA) Michel's transport medium or phosphate buffered saline for 2, 24, 48 and 120 hrs.; 3) paraffin embedding following fixation. DNA was obtained by proteinase K digestion followed by phenolchloroform extraction. DNA was cleaved with restriction endonucleases (Eco RI and Bam HI), separated by agarose gel electrophoresis, after which Southern blot hybridization with radio-labelled probes for J-heavy and T-beta genes was performed. Fixation with formalin, glutaraldehyde and B5 resulted in poor yields of DNA. MAA produced degradation of DNA and Michel's medium and PBS gave low quantities and purity of extracted DNA. Ethanol fixation consistently permitted extraction of large amounts of high molecular weight DNA suitable for hybridization studies and compared favourably with the fresh-frozen 'gold standard'. We conclude that ethanol may be the fixative of choice when transport or storage conditions limit the availability of fresh frozen tissue for DNA hybridization studies.

Acetates↗
PubMedDate not supplied

"Ring fixator" for treatment of lower leg fractures. A review of 30 cases treated by a new external fixation system.

Besides generally known therapeutic practice, indications can be discovered and more easily evaluated by using a "Ring Fixator". Applications include the following: (1) stage fractures of the tibia, (2) stabilisation of fractures of polytraumatized patients with no need for prior anatomical reduction and (3) closed lower limb fractures with severe soft tissue lesions. The major advantages of the "Ring Fixator" include the following: possible unlimited correction of primary and secondary dislocations without needing to transpose implanted Steinmann-pins or Schanz' screw; compatibility with ASIF external fixation systems for supplementary use of "Ring Fixator" elements; possible management of secondary dislocations and variable placement of pins or screws for subsequent wound debridement and muscle flap transposition. Results so far obtained using the "Ring Fixation" are illustrated by clinical examples.

Adult↗
PubMed1984

[Epiphyseal fixation with an external fixator. Biomechanical and clinical study].

Fifty one fractures of an epiphysis were treated by fixation using a new external fixator. The stability of the fixation was compared with that obtained by other types of fixator. The basis of the technique was the insertion of five pins into the epiphysis and of a series of pins in the diaphysis. Fixation between the epiphyseal and diaphyseal pins was achieved by three bars. The results obtained in 38 cases, half of them being at the proximal end of the tibia were analysed and were found to be encouraging. Only three had to be grafted secondarily. There was a low number of mal-unions. The main advantage of this method was to allow early mobilisation of the joint. The risk of sepsis did not give rise to concern provided that the rods do not cross the joint.

Biomechanical Phenomena↗