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At least 1,531 records · Page 85Linked to original sources
PubMed2004

External fixator pin tract infection model in the caprine (goat) tibia: a randomized, prospective, blinded study.

Six goats had 2 Schanz pins inserted in each tibia. Twenty-four pins were inoculated with saline or Staphylococcus aureus. Three investigators, blinded to the inoculum, evaluated 23 pins at 14 days. Clinical pin tract infections developed in all inoculated pins and in 5/12 uninoculated pins, Quantitative cultures demonstrated that infections were produced in 10/11 inoculated and in 0/12 uninoculated pins. Prediction of culture status by clinical criterion (P<.01, Fisher Exact Test) had 100% sensitivity and a 58% specificity. The prediction of infection in inoculated sites by culture criterion (P<.001, Fisher Exact Test) had a 91% sensitivity and 100% specificity. A reproducible long bone pin tract infection model was developed that produced clinically and microbiologically evident pin tract infections.

Animals↗
PubMedDate not supplied

Correction of complex foot deformities using the Ilizarov external fixator.

There are many drawbacks to using conventional approaches to the treatment of complex foot deformities, like the increased risk of neurovascular injury, soft-tissue injury, and the shortening of the foot. An alternative approach that can eliminate these problems is the Ilizarov method. In the current study, a total of 23 deformed feet in 22 patients were treated using the Ilizarov method. The etiologic factors were burn contracture, poliomyelitis, neglected and relapsed clubfoot, trauma, gun shot injury, meningitis, and leg-length discrepancy (LLD). The average age of the patients was 18.2 (5-50) years. The mean duration of fixator application was 5.1 (2-14) months. We performed corrections without an osteotomy in nine feet and with an osteotomy in 14 feet. Additional bony corrective procedures included three tibial and one femoral osteotomies for lengthening and deformity correction, and one tibiotalar arthrodesis in five separate extremities. At the time of fixator removal, a plantigrade foot was achieved in 21 of the 23 feet by pressure mat analysis. Compared to preoperative status, gait was subjectively improved in all patients. Follow-up time from surgery averaged 25 months (13-38). Pin-tract problems were observed in all cases. Other complications were toe contractures in two feet, metatarsophalangeal subluxation from flexor tendon contractures in one foot, incomplete osteotomy in one foot, residual deformity in two feet, and recurrence of deformity in one foot. Our results indicate that the Ilizarov method is an effective alternative means of correcting complex foot deformities, especially in feet that previously have undergone surgery.

Adolescent↗
PubMed2001

Patellar tendon length following opening wedge high tibial osteotomy using an external fixator with particular reference to later total knee replacement.

The aim of this retrospective study was to examine a cohort of patients who had undergone high tibial osteotomy (HTO) using the method of opening wedge hemicallotasis, and who later required conversion to total knee replacement (TKR). The incidence of patella infra and any technical difficulties encountered during TKR operation were examined. A consecutive series of 76 valgus osteotomies in 65 patients were carried out by one surgeon using a dynamic axial fixator (DAF). Later conversion to TKR, required for the progression of symptoms, was carried out in nine knees (seven patients) at a mean time from the initial osteotomy of 7 years (1.5-11). All of those patients who underwent HTO and subsequently required conversion to TKR were followed up. The patellar height was assessed by one observer in all knees pre- and post-HTO using the Insall and Salvati and Blackburne and Peel ratios. Using these criteria, only one case of patella infra occurred. There were no added technical difficulties in performing TKR as a result of the previous osteotomy and clinical outcomes using the Oxford knee score were satisfactory (34 where 48 is maximum).

Adult↗
PubMed1991

External fixator pin insertion techniques: biomechanical analysis and clinical relevance.

A series of identically matched pairs of fresh-frozen canine femora (approximating human radii in size and dimension) were used to mechanically compare pull-out strength between 4 mm predrilled, self-tapping, half-pins and 4 mm self-drilling, self-tapping half-pins with drill bit-like cutting flutes. A second biomechanical and videotape analysis was done comparing the differences of pin insertion by power versus hand drilling. Results indicated a mean 22% reduction in bone purchase of self-drilling, self-tapping pins compared with that of predrilled pins and a marked increase in depth of insertion required of the self-drilling pins for comparable pin purchase (10 mm). It was also observed that a visible "wobble factor" exists, which tends to weaken the pin-bone interface when hand drilling is performed.

Animals↗
PubMed2005

Ilizarov external fixator: acute shortening and lengthening versus bone transport in the management of tibial non-unions.

Eighteen patients with tibial shaft non-unions were treated by the Ilizarov method between March 1995 and September 2001 by the senior author. Three subgroups of six patients each were treated by either acute shortening and lengthening, bone transport or simple stabilisation with a frame. All aspects of non-union, infection, shortening, deformity and bone loss were addressed by using Ilizarov principles. There were 10 cases of infected non-unions in the entire series. Bone resection in the shortening group was between 3 and 6 cm (median 4.6) compared to 3-7.5 cm (median 5.9) in the bone transport group. Union was achieved in all the patients with the average time to union at 12.1 months, 17.2 months and 8.0 months, respectively. The bone transport group required additional bone grafting in five patients (83.3%) prior to union compared to one (16.7%) in the acute shortening group.

Adult↗
PubMed2005

Comparison of mechanical performance among different frame configurations of the Ilizarov external fixator: experimental study.

The circular frame of the Ilizarov fixator can be modified to reflect anatomic variations and treatment aims. However, these modifications in the frame system cannot always achieve the mechanical performance of the standard frame system. A standard system has two rings in each bone fragment connected by four longitudinal bars on each side of the ring. In this study, the mechanical performances of one standard and eight modified frame systems were compared. Each system was loaded on a material testing machine, with calculation of axial compression, four-point bending, and torsion. As a result, systems that were modified with drop wires and Schanz screws 45 degrees oblique to the wires on the proximal ring provided a mechanical performance closer to the standard system than systems with other modifications.

Biomechanical Phenomena↗
PubMedDate not supplied

[Organizing diagnosis of parameters of limb loading during transosseous osteosynthesis by external fixation devices].

The presented system for compression-traction osteosynthesis (CTS) involves a modified Ilizarov apparatus, a set of force and length detectors, PC controlled measuring system, a set of cables and original software. The system apparatus allows for angular displacement of bone fragments in the range of +/- 30 degrees or 0-60 degrees and lateral displacement of bone fragment edges in the joint along any azimuth in the ring plane. It was mathematically proved that the axial and angular displacement of the two apparatus ring blocks relative to each other can be described with three parameters: axial displacement of the ring center, the ring deflection (turn) angle and the ring axis turn azimuth (angle). Formulas for calculation of the displacement of three pairs of displacement control nuts so the plane of the fracture displacement angle (correction) cross the axis of the required ring plane turn azimuth (angle) were deduced for the reciprocal angular displacement of the bone fractures. No additional removable joints or the apparatus reconstruction for angular fracture displacement are needed. The CTS features the display of the current reciprocal position of bone fragment axes during the course of apparatus loading on the PC monitor.

Biomechanical Phenomena↗
PubMed2003

No difference between daily and weekly pin site care: a randomized study of 50 patients with external fixation.

INTRODUCTION: We investigated whether there were any differences in the frequency and severity of pin site infections by performing pin site care daily or once a week. We studied patients operated on for gonarthrosis by the hemicallotasis technique, using hydroxyapatite-coated pins in the metaphyseal bone and standard pins in the diaphyseal bone. PATIENTS AND METHODS: 50 patients were prospectively randomized to daily (n = 27) or weekly (n = 23) pin site care. We evaluated pin sites, the occurrence of pain (VAS), the use of antibiotics and analgesics and complications every week. Bacterial cultures were taken from each pin site at 1, 6 and 10 weeks and from the pins on removal. RESULTS: We found no differences between daily or weekly pin site care as regards the frequency and severity of pin site infections, pain, or the use of antibiotics and analgesics. Grade I infections (Checketts-Otterburns classification) occurred around 11% of the pins and grade II infections around 4%. 70% of the bacterial cultures were negative. The most frequent bacteria were coagulase negative staphylococcus and corynebacterium. Antibiotics were given an average of 47 days. More problems occurred around the proximal pins. 5/200 (all proximal) pins were clinically loose on removal. INTERPRETATION: Pin site care once a week seems appropriate.

Adult↗
PubMed2005

Quantitative assessment of tension in wires of fine-wire external fixators.

Fine-wire fixators are widely used in fracture management. Stable fixation requires the wires maintaining tension throughout the treatment. Clinical experience indicates that wire site complications relate to wire tension. However, there lacks a method to assess wire tension quantitatively in the clinic. The objective of this study was to develop a quantitative assessment method for in situ wire tension and to investigate the factors that influence the assessment. An apparatus was developed based on a linear variable differential transformer (LVDT) displacement transducer that measured the deflection of the testing wire with respect to a parallel reference wire when a constant transverse force of 30N was applied to the testing wire. The wire deflection measured was correlated with the wire tension measured by the force transducer. The experiment was performed under different conditions to assess the effect of bone-clamp distance, reference wire tension, number of wires, and fracture stiffness. The results showed that there was a significant and negative correlation between wire tension and deflection and the bone-clamp distance was the most important factor that affected the wire tension-deflection relationship. The assessment method makes it possible to investigate the relationship between wire tension and wire site complications in the clinic.

Bone Wires↗
PubMed1994

Automatic fracture reduction with a computer-controlled external fixator.

The reduction of fractures by means of an Ilizarov's fixator is obtained by successively shortening or lengthening the rods. This entails that all reduction operations of the fracture stumps be performed with a series of empirical attempts, requiring great experience and manual dexterity in the surgeon. Moreover this process involves a long exposure of both physician and patient to potentially harmful radiation due to the continuous checking of the intermediate positions on the X-ray image intensifier. In order to overcome these limits a new device has been conceived, based on the application of three stepper-motors on three-rods. Its basic principle is functionally very similar to Ilizarov's prototype. The relative motions between the two frames are carried out by controlling the three actuators with a computer, which processes the number of required steps on the basis of an algorithm, starting from a few inputs supplied by the surgeon. This article illustrates the functional kinematic study necessary for the complete automation of the reduction process. Also considered is the complex problem of the reduction trajectory definition, intended as a sequence of configurations of partial correction, obtained by formalizing in geometrical terms the empirical criteria followed by the orthopaedic surgeon in reducing fractures. Such a sequence is intended to be a suggestion for the surgeon who can visualize and possibly interact with the system to determine a trajectory harmless for the soft tissues surrounding the bone.

External Fixators↗
PubMed2003

Biologic effects of surface roughness and fluorhydroxyapatite coating on osteointegration in external fixation systems: an in vivo experimental study.

The concomitant influence of surface roughness and fluorhydroxyapatite (FHA) coating of titanium (Ti) implants on bone response was investigated. For this purpose, titanium screw-shaped implants with a lower degree (Y371) and a higher degree (TiPore300) of surface roughness, coated with FHA and uncoated, were transversally inserted into the diaphyses of sheep tibiae for 12 weeks. Four sheep received Y371 (group A) and Y371 + FHA (group B) screws and four sheep received TiPore300 (group C) and TiPore300 + FHA (group D) screws. For each type of material, the morphology and microstructure of implant-facing bone were evaluated. The host bone of each tibia was used as a control. In all groups the bone tissue did not reach a complete maturation. The higher degree of roughness, perhaps due to an excessive irregularity of the surface, induced the worst osteointegration: a fibrous tissue layer between screw and new bone tissue was often present. Nevertheless, as viewed by XRD, no crystallographic change of the apatite lattice was observed in any of the implants. In contrast, the microhardness value, an index of bone mineralization, was higher in the uncoated screws and decreased progressively in the following order: group C > group A > group B > group D. The association of plasma spraying with roughness treatment constitutes a complex system that seems to interfere with bone mineralization. A chemical change of the surface, perhaps with more Ti release or more coating degradation, could be responsible for such impairment. The authors emphasize the necessity for simultaneous evaluation of surface topography and chemistry as well as an improvement in plasma-spraying and post-processing techniques and in standard procedures for materials characterization.

Animals↗
PubMed1998

Distraction osteogenesis of the lower extremity with use of monolateral external fixation. A study of two hundred and sixty-one femora and tibiae.

We reviewed the results of distraction osteogenesis of 114 femora and 147 tibiae that had been lengthened to treat a variety of diagnoses. The femora had been lengthened an average of eleven centimeters (range, 3.5 to 17.0 centimeters), or 48 per cent (range, 8 to 86 per cent) of the original femoral length. The average total time for the treatment of the femora (use of the fixator and any subsequent immobilization) was 257 days (range, 105 to 420 days). There were 114 complications related to the femoral lengthenings, which led to eighty-seven additional operations. The tibiae were lengthened an average of nine centimeters (range, 3.0 to 15.6 centimeters), or 41 per cent (range, 9 to 100 per cent) of the original tibial length. The average total time for the treatment of the tibiae was 268 days (range, 110 to 497 days). There were 196 complications related to the tibial lengthenings, which led to 219 additional operations. The Achilles tendon was lengthened during or after seventy-three (50 per cent) of the tibial lengthenings. The femoral lengthenings that were performed to treat a limb-length discrepancy were associated with significantly higher rates of complications overall (p = 0.010) and additional operations (p = 0.023) for each percentage of length gained than those that were performed to treat achondroplasia or another skeletal dysplasia. The femoral lengthenings that were performed to treat short stature (of an endocrine or idiopathic etiology) were also associated with higher rates of complications overall and additional operations than those performed to treat skeletal dysplasias, but the rates were lower than those for lengthenings performed to treat limb-length discrepancy. The rate of complications overall associated with femoral lengthening in patients who were fourteen years old or more was significantly higher than that associated with lengthening in patients who were less than fourteen years old (p = 0.047). Femoral lengthening through the metaphysis was associated with significantly higher rates of complications overall (p = 0.031) and additional operations (p = 0.042) for each percentage of length gained than femoral lengthening through the diaphysis. The tibial lengthenings that were performed to treat Turner syndrome and idiopathic short stature were associated with significantly higher rates of complications overall (p = 0.026) and additional operations (p = 0.003) for each percentage of length gained than those performed to treat skeletal dysplasias. The rate of joint-related problems (p = 0.044) and that of additional operations (p = 0.053) after tibial lengthening in patients who were fourteen years old or more were significantly higher than those rates after tibial lengthening in patients who were less than fourteen years old. The site of the tibial osteotomy did not affect the rate of complications or additional operations. The femoral healing indices (in terms of both days per centimeter [p = 0.002] and days for each percentage of length gained [p = 0.019]) were significantly higher in the patients who were fourteen years old or more than in those who were less the fourteen years old. These values could not be used to predict an increase in the complications because of poor bone formation. The results of the present review suggest that the use of healing indices to gauge the final outcome of distraction osteogenesis is questionable; we were unable to discern significance or clinical importance from appropriately adjusted values.

Adolescent↗
PubMed1981

[External fixation of comminuted fractures of the distal extremity of the radius : technical details (author's transl)].

Experience gained by the authors in the use of external metacarpo-radial fixation for compound fractures of the lower extremity of the radius has led to their proposal of a technique that is less aggressive to the soft tissues. They employ a systematic approach to the radius and second metacarpal, followed by the use of atraumatic plates applied by means of a simple screw.

Fracture Fixation↗
PubMed1984

[Experience with the use of an external fixator in patients with multiple injuries].

The authors report on experiences with fixateur extern according to Raoul Hoffmann in 110 open fractures of second-degree and third-degree severity. The patient material comprised 90 patients, of which a total of 71 (79 per cent) had polytraumas. It was shown that good results can be expected if fixateur extern is applied immediately. The advantages of good positioning and care of soft parts are emphasized. A detailed discussion is devoted to the specific problems of polytraumatized patients with second-degree and third-degree open fractures.

Adult↗
PubMed1990

[The external fixator for children: an ideal method?].

In the years 1985-1988, 3037 fractures in children were treated in the Department of Paediatric Surgery at the University Children's Hospital, 245 of these were operated. The "Fixateur externe" was used in 30% of the 75 fractures of the diaphysis. Our experience shows that this "Fixateur externe" appliance can be used in practically any age group. Recently the stable fixation of fractures is also being practised more extensively in children; either with plate fixation, use of elastic intramedullary fixation or with a "Fixateur externe". We are of the opinion that the "Fixateur externe" should feature more extensively in the overall treatment strategy.

Adolescent↗
PubMed1992

Immediate mandibular stabilization following resection of advanced oral cavity carcinoma using the Joe Hall Morris external fixation device.

Internal mandibular fixation after resection of advanced oral cavity carcinoma with mandibulectomy has a significant complication rate. We placed the Joe Hall Morris (JHM) external mandibular appliance in 29 patients undergoing mandibulectomy for advanced oral cavity carcinoma. Fourteen patients received postoperative radiation therapy (RT). Three of 29 patients (10%) had complications associated with the JHM appliance: one patient had a broken connecting bar, a second had loosening of a single pin, and a third had loss of fixation requiring complete replacement of the appliance. Complications not associated with the appliance occurred in 8 patients (28%) including mandibular exposure (1), orocutaneous fistula (2), partial flap dehiscence (4), and flap necrosis (1). Oral continence was maintained in 26 patients, and occlusion was normal in 27. The appliance was removed in 12 weeks to 6 months in all patients. The JHM appliance allows for a reliable and rapid immediate fixation of the mandible with acceptable functional and aesthetic results, and no delay or interference with postoperative radiotherapy. Since the life expectancy of these patients is short, most do not require subsequent permanent fixation after removal of the appliance.

Adult↗
PubMed1999

[The treatment of multi-fragmental fractures of distal radius by external fixators by own construction].

A retrospective analysis of 20 multifragmental fractures of distal radius treated in Clinic of General and Hand Surgery in Szczecin from March 1996 until November 1997 with own constructed fixateur externe showed in 80% very good and good functional results according to the criteria of Gartland and Werley, Castaing. Mean follow-up was 10 months after operation. The 20 patients were on average 56.5 years old. The fixator was removed after five to at least six weeks. An additional osteosynthesis with Kirschner wires was performed in four cases.

Adolescent↗
PubMed1975

External fixation of the pelvic girdle with a trapezoid compression frame.

The compression obtained with external anchorage in the anterior and posterior part of the pelvic girdle has been studied with a measuring device in the sacroiliac joint and and the symphysis of a specimen pelvis. Two models of external frames were tested, in both of which anchorage to the pelvic bone was brought about with 3 pins inserted in the iliac crests. The results were best with a trapezoid frame and bar exerting a compressive force on the pelvic girdle. When mounted with an inclination of 70 degrees to the long axis of the body, the frame exerted considerable compression on the posterior part of the pelvic girdle. This mounting afforded good stability of the detached hemipelvis. The trapezoid compression frame is recommended as an alternative to conventional methods of treating unstable fractures and dislocations of the pelvic girdle.

Adult↗