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PubMed2006

Treatment of external fixation pins about the wrist: a prospective, randomized trial.

BACKGROUND: Pin-track infection remains one of the most troublesome complications of external fixation, in some cases compromising otherwise successful fracture treatment. METHODS: One hundred and eighteen patients (120 wrists) who had been managed with the placement of an external fixation device for the treatment of a displaced, unstable, distal radial fracture were randomized into one of three treatment groups: (1) weekly dry dressing changes without pin-site care; (2) daily pin-site care with a solution of one-half normal saline solution and one-half hydrogen peroxide; and (3) treatment with the placement of chlorhexidine-impregnated discs (Biopatch) around the pins, with weekly changes of the discs by the treating surgeon. The patients were followed at weekly intervals until the external fixator was removed. Radiographs were made biweekly. The patients were evaluated with regard to (1) erythema, (2) cellulitis, (3) drainage, (4) clinical or radiographic evidence of pin-loosening, (5) the need for antibiotics, and (6) the need for pin removal before fracture-healing due to infection. Differences in complication rates among the three groups, with adjustment for patient age, gender, and the performance of an associated open procedure, were evaluated. RESULTS: The average age of the patients was fifty-four years. Forty-seven wrists had an open procedure (either bone-grafting or open reduction and internal fixation) in addition to treatment with the external fixator. The fixators remained in place for an average of 5.9 weeks. Twenty-three patients (19%) had a complication related to the pin track, with twelve of these patients requiring oral antibiotics for the treatment of a pin-track infection. There were no significant differences among the three groups with regard to the prevalence of pin-site complications. The age of the patient was found to be significantly associated with an increased risk of postoperative pin-track complications (p = 0.04). CONCLUSIONS: We found a high rate of local wound complications around external fixation pin sites; however, most complications were minor and could be observed or treated with oral antibiotics. The prevalence of these complications was not decreased in association with the use of hydrogen peroxide wound care or chlorhexidine-impregnated dressings. On the basis of these results, we do not recommend additional wound care beyond the use of dry, sterile dressings for pin-track care after external fixation for the treatment of distal radial fractures.

Adolescent↗

PubMed2004

Use of a hybrid external skeletal fixator for repair of a periarticular tibial fracture in a Patagonian cavy.

An 8-week-old female Patagonian cavy was examined because of acute right hind limb lameness; radiography revealed a moderately displaced, comminuted fracture of the proximal third of the tibia. The fracture was stabilized with a hybrid external skeletal fixator. Two Kirschner wires were placed in the main proximal fragment, parallel to the tibial plateau and at right angles to each other. These wires were connected to a partial circular external fixator ring. Three half pins were placed in the distal fragment, and a straight connecting rod positioned on the medial side of the limb was connected to these pins and the fixator ring. A second connecting rod was positioned on the craniomedial side of the limb and was connected to the fixator ring and a fourth half pin in the distal fragment. The fracture healed without complications, and the fixator was removed 3 weeks after surgery. Hybrid external skeletal fixators combine the benefits of circular and linear external skeletal fixation methods, enabling rigid fixation of periarticular long bone fractures without adversely affecting mobility of the adjacent joint.

Animals↗

PubMed2005

Fixation durations before word skipping in reading.

We resolve a controversy about reading fixations before word-skipping saccades which were reported as longer or shorter than control fixations in earlier studies. Our statistics are based on resampling of matched sets of fixations before skipped and nonskipped words, drawn from a database of 121,321 single fixations contributed by 230 readers of the Potsdam sentence corpus. Matched fixations originated from single-fixation forward-reading patterns and were equated for their positions within words. Fixations before skipped words were shorter before short or high-frequency words and longer before long or low-frequency words in comparison with control fixations. Reasons for inconsistencies in past research and implications for computational models are discussed.

Adolescent↗

PubMed1994

Fixation disengagement and eye-movement latency.

We examined eye-movement latencies to a target that appeared during visual fixation of stationary stimulus, a moving stimulus, or an extrafoveal stimulus. The stimulus at fixation was turned off either before target onset (gap condition) or after target onset (overlap condition). Consistent with previous research, saccadic latencies were shorter in gap conditions than they were in overlap conditions (the gap effect). In Experiment 1, a gap effect was observed for vergence eye movements. In Experiment 2, a gap effect was observed for saccades directed at a target that appeared during visual pursuit of a moving stimulus. In Experiment 3, a gap effect was observed for saccades directed at a target that appeared during extrafoveal fixation. The present results extend reports of the gap effect for saccadic shifts during visual fixation to (a) vergence shifts during visual fixation, (b) saccadic shifts during smooth visual pursuit, and (c) saccadic shifts during extrafoveal fixation. The present findings are discussed with respect to the incompatible goals of fixation-locking and fixation-shifting oculomotor responses.

Attention↗

PubMed2000

Fixation patterns of idiopathic macular holes after vitreous surgery.

BACKGROUND: Evaluation of idiopathic macular holes with the scanning laser ophthalmoscope (SLO) has shown fixation to be located at or near the margin of the hole and above the horizontal meridian in most cases. However, changes between preoperative and postoperative fixation have not been well studied. METHOD: We used SLO microperimetry to determine scotomas and fixation points in 13 patients with idiopathic macular holes before and after vitreous surgery. The distance between preoperative and postoperative fixation points and the direction of movement were measured. RESULTS: Preoperatively, fixation was found to be at or near the margin of the macular hole in all eyes and was located above the horizontal meridian in most (84.6%) eyes. Postoperatively, there was a shift in the position of the fixation points. The distance between preoperative and postoperative fixation correlated with the degree of visual improvement (P = 0.032), but the direction of movement was variable. CONCLUSION: A shift in the position of fixation occurs after macular hole surgery, and the amount of shift correlates with visual improvement. From this observation, we define the term functional macular hole closure, characterized by centripetal movement of the neurosensory retina and improvement in vision, and the broader term anatomic macular hole closure, in which apparent hole closure may result from gliosis in the absence of movement of the neurosensory retina, not associated with visual improvement.

Adult↗

PubMed2000

[Fractures of the shaft of the humerus: systematic plate fixation. Anatomic and functional results in 156 cases and a review of the literature].

PURPOSE OF THE STUDY: Based on our experience with plate fixation of humeral shaft fractures and an analysis of the international literature, we attempted to answer the following questions. What functional outcome and what complications can be expected after surgery? Are the classical complications of open fracture surgery (screw fixation, wiring, plate fixation without compression.) as frequent after plate fixation using the Müller technique? MATERIAL AND METHODS: We reviewed our series of 156 humeral shaft fractures (61 p. 100 men, mean age 45 years) including 21 cases of multiple trauma and 24 multiple fractures. A floating elbow was present in 8 cases and skin opening in 16. Initial radial deficiency was observed in 28 cases. Plate fixation was the only method used for the humeral shaft fractures. We used the modified Stewart and Hundley classification. RESULTS: Postoperative paralysis occurred in 8 cases (5.1 p. 100, 5 complete paralysis); only one patient suffered persistent severe sequelae. There were also 8 malunions and 3 late consolidations. Consolidation rate was 94.2 p. 100, sepsis rate was 1.5 p. 100. Good or very good outcome was achieved in 86.6 p. 100 of the cases. DISCUSSION: In the literature, (71 series, 5 000 patients), plate fixation of humeral shaft fractures has given very good functional results with few initial failures, malunions or cases of sepsis. Radial paralysis is cited as a complication in 6.5 p. 100 of all plate fixations but is reversible in 90 p. 100 of cases. Classical orthopedic methods and centromedullar techniques produce more stiffness. The Sarmiento cuff can give good results after rigorous patient selection. CONCLUSION: Plate fixation according to the Müller technique is a reliable osteosynthesis method with few initial failures or malunions as evidenced by data in the literature. Infection is also rare. Although the radial nerve risk makes this technique rather difficult, excellent functional results can be achieved.

Adolescent↗

PubMed2001

[Progressive limb lengthening with a centromedullary nail versus an external fixator: experimental study in sheep].

PURPOSE OF THE STUDY: Progressive limb lengthening with an external fixator often leads to pin-related complications. A new technique allowing progressive lengthening with a centromedullary nail without external fixation has been developed. This original double-locked device consists of matching male and female components fitted with a continuous thread. Lengthening is achieved via a one-way ratchet system. Twelve back-and-forth movements produce 1.25 mm lengthening. MATERIAL AND METHODS: We tested this new device on 20 sheep and compared results with external fixation lengthening in 20 other sheep. The animals were divided into groups for sacrifice on days 5, 10, 20, 45 and 90. Serial x-ray were obtained for all animals. In the 45-day and 90-day groups, histomorphometric (trichrome goldner coloration and polarized light microscopy) and densitometric studies were also performed. Bone mineral density (BMD) was determined and bone trabecular density (BTD) and trabecular bone volume (TBV) were expressed in percent of bone trabecular surface area. RESULTS: Mean lengthening in the 45-day and 90-day groups was 39 mm for the nail and 20 mm for external fixation (1 mm/day). At 90 days, 3 sheep out of 4 had consolidated radiologically with external fixation and 2 out of 4 with the nail. BMD was slightly better for external fixation (0.811 vs 0.695/cm(2)). This difference could probably be attributed to the greater lengthening obtained with the nail. At 45 days, BMD was the same (0.6 g/cm(2)) for both devices. BTD was nearly two-fold higher for the nail compared with external fixation (59.65% vs 32.61% at 90 days), most probably due to primary bone formation. The histomorphometric study allowed an analysis of the osteoid border. Bone quality obtained in the bone regenerate with the nail was superior to that obtained with external fixation. Primary bone formation resulted from membrane ossification with direct transformation of fibroblasts into osteoblasts. CONCLUSION: This work demonstrated that progressive lengthening can be achieved with a specifically designed centromedullary nail without iterative opening of the operative site. Tolerance to this type of device and quality of the bone regenerate are altogether satisfactory.

Absorptiometry, Photon↗

PubMed2001

Percutaneous fixation of scaphoid fractures.

The scaphoid proximal pole and waist fractures presented here were treated by a novel dorsal percutaneous technique with arthroscopic assistance. All fractures healed, with good final functional results and no complications. The advantages of the dorsal percutaneous approach to scaphoid fixation are: (1) the proximal-to-distal placement of the guide pin and screw allow for more precise placement along the central axis of the scaphoid, which decreases healing time and reduces risk of screw thread exposure. (2) The dorsal approach avoids injuring the vulnerable volar ligament anatomy. And (3) the insertion of the screw from the proximal to distal direction allows the more rigid fixation of proximal scaphoid fractures. Arthroscopy allows confirmation of fracture reduction and screw implantation as well as evaluation of concurrent ligament injuries not detected with standard imaging. Percutaneous K-wires act as joysticks to reduce and compress fracture fragments prior to fixation. The presented technique allows for early, rigid internal fixation with minimal associated morbidity. Patients successfully treated with this technique include those with stable and unstable acute fractures of the scaphoid at all locations, including the proximal pole. Nondisplaced fractures that present with delayed or fibrous union without evidence of avascular necrosis, cyst formation, or bony sclerosis may also be treated with this technique. This technique allows for faster rehabilitation and an earlier return to work or avocation without restriction once CT scan confirms a solid union. Some articles document extraordinary rapid healing by standard radiographs; however, we caution that scaphoid bone healing cannot accurately be determined without CT scan. Percutaneous, arthroscopically assisted internal fixation by a dorsal approach may be considered in all acute scaphoid fractures selected for surgical fixation. The dorsal guidewire permits dorsal and volar implantation of a cannulated screw along the central axis of the scaphoid. This technique permits the reduction of displaced fractures and the stable repair of fractures of the proximal pole. In addition, selected scaphoid fibrous union or delayed union may also be repaired, with realistic expectations of healing. The proven benefits of the percutaneous technique include decreased soft tissue trauma; arthroscopic visualization of the fracture, ensuring anatomic reduction; and stable fixation, allowing early physical rehabilitation. The theoretical benefits of the technique include decreased risk of interruption of the tenuous scaphoid blood supply. Percutaneous internal fixation of scaphoid fractures provides faster rehabilitation, earlier return to work, and quicker bony union in most patients.

Arthroscopy↗

PubMed2001

[Strain gauge measurements on a one-side external fixation: a prospective series of 11 tibial shaft fractures].

PURPOSE OF THE STUDY: External fixation is often the treatment of choice for open complex fractures of the tibia. For closed tibial shaft fractures, it is generally a second choice alternative. The purpose of this study was to determine whether fusion of closed and open fractures of the tibia can be successfully achieved with a one-side external fixator equipped with strain gauges and to evaluate complications of this type of treatment. MATERIAL AND METHODS: A consecutive series of 11 mid shaft fractures of the tibia (4 closed fractures and 7 Gustilo grade I and II open fractures) in 11 patients (mean age 29 years) were treated with a one-side external fixator. Strain was measured weekly to adjust the treatment. A Sarmiento walking cast was applied in all cases 4 weeks after removal of the external fixator. RESULTS: All 11 fractures healed without complications and without pin tract infection. Mean delay to consolidation was 20.5 weeks (range 13 - 29.5 weeks). One patient required a revision procedure for decortication and bone graft at 12 weeks. Weight bearing (50% of body weight on the injured limb) was achieved at 6.7 weeks (mean) and total weight bearing at 11.9 weeks. The external fixator's strain curves were compatible with normal healing in 3 cases, with slow healing in 3 and with retarded healing in 3 others. Two of the curves did not show recognizable patterns despite a favorable clinical and radiological course to healing. DISCUSSION: Early detection of a pathological pattern of fracture healing followed with a strain gauge enabled adaptation of treatment in all cases. Decortication with bone grafting was necessary in one patient. In two other cases, compression of the fracture with the external fixator or dynamic locking were sufficient to achieve a favorable healing pattern. This small series demonstrated that bone healing can be achieved within usual delays with external fixation and without major complications. Use of strain gauges on the external fixator allowed early detection of retarded healing and subsequent modification of the treatment protocol. This type of treatment might be an interesting therapeutic alternative for the treatment of closed fractures of the tibial shaft.

Adult↗

PubMedDate not supplied

Ender nailing versus external fixation in the stabilization of type III open tibial shaft fractures.

UNLABELLED: Management of severe open tibial shaft fractures presents a difficult challenge to the orthopaedic surgeon. They are frequently associated with loss of limb, infection and high levels of morbidity. All the authors considered, now, that there are five keys to successful treatment: antibiotic therapy, radical debridement and pulsed lavage irrigation, stabilization of fracture with minimal further devascularization, early soft tissue coverage and early bone-grafting. It rests, also, a number of controversies in the management of open tibial fractures, not least of which is the method of fracture stabilization: the choice between intramedullary nailing and external skeletal fixation, the use of reamed or unreamed nails. MATERIAL AND METHODS: Fifty-seven patients with 62 open fractures of the tibial shaft type IIIA, B and C (Gustilo) were treated between 1.01.1994 and 31.12.1998 in the Department of Orthopaedic Surgery of the Emergency Hospital, Iasi, Romania. There were 29 cases type IIIA fractures, 26 cases type IIIB and 7 cases type IIIC (Mess score showed the viability of the limb). Our patients were 36 males and 21 females; their mean age was 36 years (range 17 to 70). Forty-six patients were injured in road traffic accidents and 11 in other traumatic incidents. In 33 cases the skeletal stabilization was achieved by Ender nailing under general or regional anesthesia. In 15 cases we used a bilateral uniplanar external fixator (Burghele) and 14 fractures were stabilized with an Ilizarov external fixator. We note a secondary amputation after the failure of the revascularization of the limb in a type IIIC fracture. RESULTS: All fractures united; the mean time to union was 30.2 weeks--in the external fixation group and 26.4 weeks--in the Ender nailing group. Malunions occurred slightly more frequently in the external fixation group that in the Ender nailing group (15.7% versus 5.8%). We noted--also--more secondary procedures required in the external fixation group. The infection rate was 3 of 33 (9.1%) in the Ender nailing group compared to 4 deep (13.8%) and 8 pin-tract infection (27.6%) in the external fixation group. CONCLUSIONS: Our study suggests that Ender nailing has several advantages over external fixation in the management of severe open tibial shafts fractures. Based on these results, over the last years, in our Department we use mainly the Ender nailing technique, as we consider it a better approach for these type of lesions.

Adolescent↗

PubMed2003

Removal of internal fixation in pediatric patients.

OBJECTIVE: Internal fixation devices are commonly used in the surgical treatment of many orthopedic conditions. Their prolonged presence, however, has been associated with potential complications. Many surgeons advocate the routine removal of internal fixation in the pediatric age group. In this report we present our experience with removal of internal fixation in pediatric patients and evaluate the benefits and difficulties of doing so. METHODS: A retrospective analysis of 304 pediatric patients who underwent removal of internal fixation implants for various indications at the Armed Forces Hospital, Riyadh, Kingdom of Saudi Arabia between January 1985 and December 1999, was carried out. RESULTS: A total of 176 males and 128 females were included. Their mean age at time of removal of internal fixation was 11 years (range 2-18). The fixation device was removed at an average of 16.3 months (range 10-40) after implantation. One hundred and twenty (39.5%) patients had the initial fixation for the treatment of fractures. For all 304 patients, late removal of the implant was found to be more difficult than early removal. Implants around the hip and pelvis were more difficult to remove than other locations. CONCLUSION: Our experience supports the indication for timely removal of internal fixation devices in the pediatric population. When carried out on a routine basis it can avoid the difficulties associated with the late removal of implants.

Adolescent↗

PubMed1992

[Stabilizing the pelvic ring with the external fixator. Biomechanical studies and clinical experiences].

Experimental studies were performed on anatomic pelvis specimens. In different series of experiments the positioning of the screws and the assembly of the external fixator were changed. We tried fixing the external fixator to the screws at varying distances from the body surface. For stabilisation of the fractured pelvic girdle a self-constructed "bow fixator", fixed to supra-acetabular screws with proximal compression and distal traction showed the best results. Homogeneous distribution of the pressure could be achieved on the unstable dorsal pelvic ring structures. In clinical routine we used the triangular external fixator, which in the experimental situation yielded results close to those of the bow fixator. External fixation of the pelvic girdle has been performed 128 times since 1977, in January 1991 a prospective study was started. For Tile type B injuries the external fixator itself represents an effective, minimally invasive system, but type C fractures often require an additional internal fixation of the dorsal lesion.

Acetabulum↗

PubMed2003

Effects of drought stress on legume symbiotic nitrogen fixation: physiological mechanisms.

Drought stress is one of the major factors affecting nitrogen fixation by legume-rhizobium symbiosis. Several mechanisms have been previously reported to be involved in the physiological response of symbiotic nitrogen fixation to drought stress, i.e. carbon shortage and nodule carbon metabolism, oxygen limitation, and feedback regulation by the accumulation of N fixation products. The carbon shortage hypothesis was previously investigated by studying the combined effects of CO2 enrichment and water deficits on nodulation and N2 fixation in soybean. Under drought, in a genotype with drought tolerant N2 fixation, approximately four times the amount of 14C was allocated to nodules compared to a drought sensitive genotype. It was found that an important effect of CO2 enrichment of soybean under drought was an enhancement of photo assimilation, an increased partitioning of carbon to nodules, whose main effect was to sustain nodule growth, which helped sustain N2 rates under soil water deficits. The interaction of nodule permeability to O2 and drought stress with N2 fixation was examined in soybean nodules and led to the overall conclusion that O2 limitation seems to be involved only in the initial stages of water deficit stresses in decreasing nodule activity. The involvement of ureides in the drought response of N2 fixation was initially suspected by an increased ureide concentration in shoots and nodules under drought leading to a negative feedback response between ureides and nodule activity. Direct evidence for inhibition of nitrogenase activity by its products, ureides and amides, supported this hypothesis. The overall conclusion was that all three physiological mechanisms are important in understanding the regulation of N2 fixation and its response of to soil drying.

Carbon Dioxide↗

PubMed2005

[Large variation in indications for internal fixation or arthroplasty in displaced femoral neck fracture; results of a questionnaire distributed among general surgeons in 20 hospitals].

OBJECTIVE: To describe the treatment protocols for displaced femoral neck fractures in all 8 university hospitals (UH) and 12 general hospitals (GH). DESIGN: Descriptive; questionnaire. METHOD: Questionnaires were distributed to general surgeons who also perform traumatology surgery. They were requested to give succinct answers to questions about local protocol for the maximum permissible time interval between hip trauma and operation, indications for internal fixation and arthroplasty, operative technique and postoperative degree of weight-bearing in patients over 60 years of age with a displaced femoral neck fracture. RESULTS: Internal fixation and arthroplasty were performed within 24 and 48 hours respectively in 95% of all hospitals. A biological upper age limit of between 65 and 80 years old was the most commonly quoted indication for internal fixation in 70% of all hospitals. In 83% of GH dementia was considered an indication for arthroplasty as opposed to 0% in UH. Poor bone quality, immobility, comminution and inadequate reduction were incidentally quoted indications for arthroplasty. Rheumatoid arthritis, arthrosis and pathological fracture were contra-indications for internal fixation in all hospitals. Operative techniques for internal fixation and arthroplasty were similar in both UH and GH. After internal fixation, full weight-bearing was recommended in all UH and partial weight-bearing in 7 (58%) of GH. Following arthroplasty all protocols prescribed full weight-bearing. CONCLUSION: The variation in indications for internal fixation or arthroplasty reflects the lack of studies that demonstrate clearly which patient can be treated optimally with which treatment modality. There were few differences in the operative techniques of internal fixation and arthroplasty between the hospitals.

Age Factors↗

PubMed2006

What do eye-fixation patterns tell us about unilateral spatial neglect?

PURPOSE: Eye-fixation patterns, which include ocular searching and fixation, may change with tasks, stimuli, and instructions. This article reviews our studies over 18 years on eye-fixation patterns of neglect patients and aims to elucidate the visuospatial processing of unilateral spatial neglect. METHODS: We recorded eye-fixation patterns when patients with neglect bisected a line in various conditions. RESULTS: Patients with neglect rarely searched to the left side when bisecting a line of the ordinary length (e.g., 200 mm). They persisted in fixating a right-side point, at which they later marked the subjective midpoint. They made no effective comparison between the leftward and rightward extents not only for a whole line but also for its explored right segment. Where they 'favored' to fixate as the subjective midpoint depended strongly upon the location of the right endpoint in space. Their representational image of a line was also estimated with modified line bisection tasks performed on a touch-panel display. CONCLUSIONS: For patients with neglect, the representational image of a line may be formed on the basis of the attended segment between the right endpoint and the favored point of fixation. The line bisection task, if combined with recording of eye-fixation, would further contribute to elucidation of the mechanisms underlying neglect.

Cues↗

PubMed1991

[A study on the appropriate fixation for the procedures for the better preservation of cellular antigenicity and morphology of the blood smear in immunocytochemistry: an improvement of the immunostain technique using alkaline-phosphatase (ALP) as a labeling enzyme].

The authors previously reported a new coloration method which utilized hexazotized newfuchsin as a coupler for the immuno-enzyme-cytochemistry. This procedure used alkaline-phosphatase (ALP) as the labeling enzyme. The insolubility of the reaction product to organic solvents made it possible to prepare permanent slides. However, this suffered from several drawbacks, due to the fixation procedures, in the preservation of better morphology and antigenicity of the cell. The present study was undertaken to overcome such problems by modifying the fixation procedure. The study utilized twenty monoclonal and polyclonal antibodies commonly used in immunohematological staining. Various fixative solutions and timing of fixation were evaluated. The results indicated that; 1) the best fixative solution was a mixture of buffered paraformaldehyde (PFA) and acetone (10 ml 40% PFA solution, 10 ml pH 6.6 0.02 M phosphate buffer, 20 ml distilled water, 60 ml acetone, with pH adjusted to 6.6-7.4 with HCl) and 2) the fixation should be performed just before the immunostain. The results further showed that unstained smear slides, when freshly air dried and stored in a desicator, could maintain various differentiation antigens (CD2, 3, 4, 5, 8, 10, 14, 15, 16, 19, 25, L26, HLA-DR) for at least 4 weeks without any change in the immuno-reactivity. Thus, we conclude that this improved fixation procedure is an optimum fixative and should be used in routine application of the immunostain method for blood smears.

Alkaline Phosphatase↗

PubMed1991

[Dorsal atlanto-axial screw fixation. A stability test in vitro and in vivo].

Clinical and biomechanical testing of the stability of atlantoaxial fusions was studied. For biomechanical testing, four different techniques for posterior atlantoaxial fusion were tested: (1) wire fixation with one median graft; (2) wire fixation with two bilateral grafts; (3) transarticular screw fixation and two bilateral posterior clamps. Ten fresh human cadaveric specimens were tested. The loads applied were 6 pure moments. The motion of C1 relative to C2 in the intact, injured and mechanically fixed spine were measured and compared. In flexion/extension the difference between Brooks, Magerl and Halifax were not significant, but each was significantly less than the Gallie-system. For the anterioposterior translation the stabilization of all fixation techniques was about equal. In axial rotation measuring the translations between C1 and C2, the screw-fixation technique proved to be the most stable. For lateral bending, there was no significant difference between the different techniques, except for Galliefixation, but the screw-fixation technique allowed the least motion. In additional in vivo tests ten patients with posterior atlantoaxial fusion by the transarticular screw-fixation technique underwent bending X-rays of the upper cervical spine as well as computertomograms. Solid fusion was achieved in all patients. Both investigations proved the reliability of the multidirectional stability of the atlantoaxial screw fixation technique.

Atlanto-Axial Joint↗

PubMed1990

[SAF--an alternative fixation solution for parasitological stool specimens].

A comparative parasitological study in 3 collectives using 2 different fixatives for stool samples (SAF and MIF) was carried out. The SAF fixative consistently showed a significantly higher sensitivity for parasitic protozoa than the MIF fixative (Entamoeba histolytica 90.0% vs. 64.4%, Giardia lamblia 97.7% vs. 64.4%), which was due to an increased detection of cysts of both species. No difference in sensitivity for helminths was found. The cheap, simple formula and, due to the absence of mercury, the low toxicity are further advantages of the SAF fixative. Moreover, contrary to the MIF fixative, the SAF fixative permits the use of a wide range of staining techniques starting from fixed specimens. These results led to the replacement of the MIF fixative by the SAF fixative at the Diagnostic Center of the Swiss Tropical Institute.

Acetates↗