Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “External Fixators”

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 487 records · Page 27Linked to original sources
PubMed1996

External fixation for distal radius fractures: adverse effects of excess distraction.

External fixation is accepted treatment for some distal radius fractures. Ligamentotaxis is the basis for the technique, and failure to recognize its limitations can lead to excess distraction. This paper discusses potential complications of excess distraction as well as its effect on outcome. Supplemental fixation techniques and multiplanar ligamentotaxis are advocated to improve outcome when external fixation is used.

Fracture Fixation↗
PubMed1998

The use of external fixators for finger injuries: pin placement and tethering of the extensor hood.

External fixation is useful for the treatment of selected injuries to the hand. Some authors have suggested that external fixation of a phalanx may tether the extensor hood, thereby hindering active movements and predisposing to permanent adhesions. There is no consensus as to the best site for placement of the pin to minimise these problems. This study was performed on cadaver specimens to investigate the influence of the pin site on the range of simulated active movement of the interphalangeal joint. The dorsal midline position produces least interference with the extensor mechanism; radial and ulnar to this, interdigitating oblique fibres prevent a clean longitudinal split in the direction of gliding thus limiting movement of the extensor hood. At the proximal phalanx, positioning of the pin just off the midline avoids the thickening of the proximal median hood, whereas at the middle phalanx, a true midline position utilises the bare area at its base.

Bone Nails↗
PubMed1995

An investigation of the bending stiffness of and the plane stresses generated by a flanged external fixator pin.

In an attempt to reduce pin loosening, a flanged external fixator pin has been designed and its bending stiffness has been compared with that of a standard pin. The pins were inserted into pilot holes previously drilled into a piece of teak hardwood. Loads of different magnitudes were applied at a fixed moment arm and force-deflection curves were obtained. Thereafter, percentage stiffness increase was calculated for each pilot hole size. The results show that the addition of a collar to the external fixator pin increases its stiffness and its ability to resist bending forces. In a parallel study, the stresses generated at the pin-bone interface by this pin and a standard pin were compared using finite element analysis techniques. The results show that the flange significantly reduced the stresses generated at the pin-bone interface. In addition, stresses were dissipated over a wider area.

Biomechanical Phenomena↗
PubMed1987

External fixation of open comminuted fractures of the proximal phalanx.

External fixation is an accepted method of treatment for many injuries, however, only a limited number of reports concern its use in open, comminuted fractures of the hand. Ten patients with eleven fractures of the proximal phalanx were treated using the AO/ASIF small external fixator. Five fractures involved the interphalangeal joint (IPJ), two the metacarpophalangeal joint (MPJ), and four the shaft. Nine fractures were caused by small caliber gunshot wounds, one was due to a power saw injury, and one occurred during a three wheeler accident. The patients with interphalangeal joint involvement all had extensive involvement of one or both of the joint surfaces. The fixator was placed across the joint and a stable ankylosis allowed to occur with the IPJ in 30 degrees to 40 degrees of flexion. MPJ motion averaged 75 degrees in these patients while distal interphalangeal joint (DIPJ) motion averaged 20 degrees. The four patients with shaft fractures all healed, but three required bone grafting. These patients averaged 85 degrees of MPJ motion, 25 degrees of proximal interphalangeal joint (PIPJ) motion, and 30 degrees of DIPJ motion. One patient with metacarpophalangeal joint involvement regained 85 degrees of MPJ motion but had limited motion at the PIPJ and DIPJ. The other patient with MPJ involvement suffered massive bone loss; a ray amputation was eventually performed. Complications included pin tract drainage in three of the eleven fractures and slight loss of reduction in two fractures. The best clinical results occurred when the fixator was used as a digit salvage procedure in interphalangeal joint fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2002

State of the art review: techniques to avoid pin loosening and infection in external fixation.

UNLABELLED: The purpose of this manuscript is to review techniques of optimizing the interface between the bone and pin in external fixation to minimize pin loosening and infection. CONCLUSIONS: Among the different techniques to improve the bone-pin interface in external fixation, coating the pins with hydroxyapatite proved to be the most effective. In a highly loaded animal study, three pin types were compared. Type A remained uncoated, type B was coated with hydroxyapatite, and Type C was coated with titanium. Radiographic rarefaction of the bone pin tract was lower in type B pins. Extraction torque was thirteen times higher in type B pins compared to type A and two times higher compared to type C pins. Extraction torque was significantly lower compared to the corresponding insertion torque in both types A and C. In contrast, in the hydroxyapatite coated pins there was no difference between extraction and insertion torque. At sixty times magnification, bone pin contact of type B and C pins was significantly higher than type A. At 10,000 times magnification direct bone pin contact was found only in type B pins. In a clinical study the pin insertion and extraction torque forces were measured in a study of seventy-six external fixation pins in nineteen patients treated with hemicallotasis for osteoarthritis of the medial side of the knee. The patients were randomized to be treated with either standard tapered pins or tapered pins coated with hydroxyapatite. Extraction torque of the hydroxyapatite coated pins was higher than the standard ones in both cancellous and cortical bone. These studies show that in hydroxyapatite coated pins there is no deterioration of the bone-pin interface strength and there is optimal bone-pin contact. Among the various pin types coated with hydroxyapatite, the best results were obtained with the tapered pins.

Animals↗
PubMed1988

External fixation and recovery of function following fractures of the distal radius in young adults.

The functional recovery from Colles' fracture was studied prospectively over a 1-year period in 106 patients randomized to treatment by plaster or external fixation. Although external fixation allows immediate mobilization of the wrist and leads to a much better anatomical result, these factors did not permit any improvement in the wrist's early functional recovery. One year following injury the grip strength of the fixator-treated group was significantly superior to that of the plaster-treated patients.

Adult↗
PubMed2004

Comparison of canine mandibular bone regeneration by distraction osteogenesis versus acute resection and rigid external fixation.

The present study was performed (1) to explore the mechanism of skeletal healing following distraction osteogenesis of the mandible and to evaluate whether the same process is involved following acute mandibular resection and rigid external fixation, and (2) to examine the role of the periosteum in skeletal healing in both models. The study was performed using 16 mongrel dogs divided into two equal groups. In the first group, distraction of 20 mm was performed at a rate of 1 mm/day. In the second group, bone resection of 20 mm was performed, followed by rigid external fixation. The buccal periosteum was stripped in four dogs from each group, and the periosteum was left intact in the remaining four dogs. Dogs were euthanized after a survival period of either 2 or 3 months, and the new bone regenerate was evaluated. Analysis consisted of three-dimensional computed tomography scanning, histometric analysis, and immunostaining. Analysis of bone mineral content in the residual gap was conducted. Bone mineral content was increased in 3- versus 2-month survival for all groups (p < 0.05). The distracted groups had greater bone mineral content than their acutely resected counterparts, with the difference achieving statistical significance by 3-month survival (p < 0.05). Although periosteal preservation resulted in increased bone mineral content over time for all groups (p = 0.044), periosteal preservation had no significant effect on bone mineral content in the distracted groups. After periosteal stripping, however, bone mineral content was significantly increased in dogs that underwent distraction rather than acute resection and rigid external fixation (p = 0.022). Regarding histometric analysis, analysis of fibrous tissue content in the bone regenerate demonstrated that by 3 months the distracted groups had significantly less fibrous tissue in the new bone regenerate than did the acutely resected groups (p < 0.001). Regarding immunostaining, diffuse localization of transforming growth factor-beta1 was observed in all groups at 2 months, returning to nearly baseline levels by 3 months. These data demonstrate that significant bone formation in a segmental gap can be achieved after acute mandibular resection and rigid external fixation if the periosteum is preserved. However, after periosteal injury or stripping, significant bone formation can only be achieved by distraction osteogenesis. In both processes, bone formation is preceded by up-regulation of transforming growth factor-beta1.

Animals↗
PubMed2006

Is staged external fixation a valuable strategy for war injuries to the limbs?

UNLABELLED: High-energy weapons or blast injuries usually result in substantial tissue damage and are serious medical and public health problems. We report our experience with staged external fixation for war injuries to the extremities. Forty-seven patients with 64 high-energy limb fractures caused by war weapons were retrospectively reviewed. The fractures were associated with severe soft tissue damage. There were 14 Gustilo-Anderson Type IIIA fractures, 40 Type IIIB fractures, and 10 Type IIIC fractures. Soft tissue débridement followed by axial realignment of the fractured bones with immediate skeletal stabilization using the AO/ASIF unilateral tubular external fixator was performed on the day of admission. The primary tubular fixators were exchanged 5 to 7 days later for Ilizarov frames. Delayed primary closure, skin grafts, or flaps were used for soft tissue coverage. The mean followup was 40 months, and the Ilizarov/hybrid external fixator was the definitive treatment in all patients. Bone union was achieved at an average of 8 months in 58 (90.6%) fractures. Three patients had nonunions and one patient required an amputation. Two patients were lost to followup. Staged external fixation is a valuable strategy for treatment of war injuries to the extremities. LEVEL OF EVIDENCE: Therapeutic study, Level IV. See the Guidelines for Authors for a complete description of levels of evidence.

Adult↗
PubMed1995

Biomechanical study on osteotomized tibias fixed with unilateral adjustable external fixator.

Five fresh tibias removed from 30-40 years old dead males were osteotomized at one-third supra-medium segment and then fixed by an unilateral adjustable external fixator (UAEF) to be used as a model of external fixation of tibial fracture. For each loading test under different configurations of UAEF, the ratio of the force-displacement was used to determine its stiffness value. The weakest mode of the UAEF device is in AP bending. Under each mode of compression, distraction, anteroposterial and lateral bending and torsion loading, increasing the pin number or pin diameter or pin separation, and/or reduction of pin group separation can significantly increase the stiffness values of UAEF (P < 0.01). These data revealed that UAEF is suitable for the external fixation of tibial fracture.

Adult↗
PubMed1993

Post-traumatic osteoporosis and algodystrophy after external fixation of tibial fractures.

The incidence of two forms of post-traumatic osteoporosis and algodystrophy in the ankle region of 20 patients with displaced diaphyseal fractures of the tibia treated with external fixation were studied. Acute localised osteoporosis (ALO) occurred in 14 (70 per cent) and 5 (25 per cent) developed algodystrophy. ALO was significantly less frequent in matched patients treated by internal fixation or by external plaster-of-Paris (POP) cast. Regional osteoporosis (RO) was most common in POP patients. The presence of ALO may indicate the development of algodystrophy following tibial fracture. Our findings suggest that external fixation may predispose to ALO and algodystrophy.

Acute Disease↗
PubMed1983

Guidelines for treatment of open fractures and infected pseudarthroses by external fixation.

There are three phases in the treatment of open fractures and infected pseudarthroses by the Hoffmann external fixator. During the initial phase a careful surgical debridement is performed in the bony tissues, and the external fixator is applied in a manner appropriate to the type and level of the lesion site (double- or triple-frame mounting; additional anchorages; neutralization, compression, or distraction; ligamentotaxis). During the intermediate phase both the nursing of the patient and care of the apparatus are critical for the avoidance of complications; it is during this period that granulation tissue must develop and bone infections must be controlled. In the final phase the loss of osseous substance must be treated by various means (regular tightening of the external fixator; Papineau's technique; intertibiofibular graft; free microvascular bone transplantation technique.

Arm Injuries↗
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↗
PubMed1987

The early healing of tibial osteotomies stabilized by one-plane or two-plane external fixation.

The pattern of early healing of canine tibial osteotomies associated with two different types of external fixation devices was investigated. Two-plane fixation was significantly more rigid than one-plane fixation in three of the five loading conditions that were examined. The more rigid fixation allowed less lateral displacement at the site of the osteotomy, induced less formation of callus early in the healing process, permitted direct bridging by osteons more frequently, and provided healing that was more rigid early in the process of repair. In the later stages of healing there were no differences in the quantity of callus or in the strength of the healing bone. In this canine model, external fixation with higher rigidity resulted in rapid union that differed from the union that resulted after less rigid external fixation only with regard to porosity, torsional stiffness, and displacement at the site of the fracture.

Animals↗
PubMed1999

Biomechanical analysis of dynamic external fixation devices for the treatment of distal radial fractures.

BACKGROUND: Several dynamic external fixation devices have been introduced to permit early functional treatment of unstable distal radial fractures. METHODS: An intact cadaver wrist was spanned by a dynamic external fixator. Forces between the fixator and the radius were recorded during passive motion using a single, strain-gauged pin. A device with a double ball joint was compared with a new, experimental fixator with 3 degrees of freedom and its center of rotation coincident with that of the wrist. RESULTS: During flexion and extension, the pin load was approximately the same for both fixators. Radioulnar deviation resulted in high pin loads for the fixator with ball joints; the new device showed no considerable pin load. CONCLUSION: The new device has a high degree of kinematic compatibility with the natural wrist joint. When used for the treatment of distal radial fractures, it should provide favorable conditions for the maintenance of fracture reduction compared with a device with an offset ball joint.

Biomechanical Phenomena↗
PubMed1989

Biomechanics of the Ilizarov external fixator.

The rigidity of the Ilizarov external fixator was evaluated by means of the techniques of Briggs and Chao, and compared to their findings for the Hoffman-Vidal external factor. A typical fibular fixator consisting of 8 crossed K wires and 4 rings with supporting struts was affixed to a fiberglass-filled epoxy bone fracture model. The ensemble was tested with an MTS servohydraulic testing machine in axial loading, bending (A-P, L-M), and torsion. Displacement transducers were placed on the frame and the bone to determine relative motion. The Ilizarov frame was relatively stiff in compression; failure occurred at about 100 kg due to slippage at the wire holders. In bending, it was much less rigid than the Hoffman-Vidal fixator due to bowing of the transverse wires and slippage of the bone along these wires. Stiffness is related to the wire-bone orientation: wires parallel or nearly parallel to the applied force provide little resistance to deformation. In torsion, the laxity in the system is due primarily to wire deflection or wide spacing between adjacent rings. Stiffness in compression and bending increased as a function of wire tension to about 130 kg (further tightness was not possible due to slippage at the wire holder). The Ilizarov fixator is less rigid than other fixators in all loading modes, particularly in axial compression. This may prove to be clinically beneficial as evidenced by increased osteosynthesis. However, the existing system has many sites of laxity. Care must be taken in frame construction to ensure adequate stability and necessary stiffness.

Biomechanical Phenomena↗
PubMed1991

External fixation of the sternum for thoracic trauma.

A flail chest with a manubriosternal separation in a man with multiple injuries was treated with an external fixator applied to the sternum and the manubrium. Pain and ventilatory function were improved, permitting immediate postoperative extubation and prompt patient mobilization. The external fixator was removed after fracture union at 2 months. One year after injury, the patient's pulmonary function was normal. External fixation is an alternative to other methods of sternal fracture stabilization.

Abdominal Injuries↗
PubMed2005

[The effect of definitive continuous distraction employed with the Ilizarov type external fixation system on fracture healing: an experimental rabbit model].

OBJECTIVES: The objective of this study was to evaluate the effect of definitive continuous distraction (DCD) employed through an Ilizarov type external fixator on fracture healing in a rabbit tibia model. METHODS: Fifteen mature New Zealand white rabbits weighing 2.8 to 4.0 kg were randomly assigned to three groups following osteotomy of the tibia and fibula. The first group (controls) was treated only with the Ilizarov type external fixator while the second and third groups were subjected to DCD amounting to 10% and 30% of the body weight, respectively, being employed through modulated springs on the Ilizarov external fixation system. All the rabbits were evaluated by radiographs on the 12th, 21st, 28th, and 35th days following surgery and were sacrificed on the 45th day. Radiographic evaluations were made according to the Lane and Sandhu's scoring system, and histologic evaluations according to the scoring system proposed by Heiple et al. The results were analyzed using the Kruskal-Wallis test. RESULTS: The highest radiographic and histologic scores were obtained from the second group, being 8.6 and 11.6, respectively (p<0.05). Radiographic and histologic scores of the third group were lower than those of the control group. CONCLUSION: Application of DCD of 10% of body weight through modulated springs on the Ilizarov external fixator improves fracture healing while a greater amount of instability results in delayed healing.

Animals↗
PubMed2005

Hinged elbow external fixation for severe elbow contracture.

BACKGROUND: When it was first introduced, it was hoped that hinged external fixation with a built-in gear mechanism for applying passive motion and static progressive stretch by turning a dial would improve the arc of ulnohumeral motion, by gradually stretching contracted muscles, after open release of a severe elbow contracture. METHODS: Forty-two patients were evaluated at an average of thirty-nine months after operative release of a severe posttraumatic elbow contracture (defined as < or =40 degrees of motion). Twenty-three patients had been treated, during the early part of the study, with a hinged external fixator that incorporated a worm gear to apply static progressive stretch postoperatively. These patients were compared with nineteen patients who had been treated without hinged external fixation during the later part of the study, when the hinge was used less frequently. The operative techniques did not otherwise change during the study period. Demographic and injury characteristics as well as associated problems were comparable between the two groups. RESULTS: The average gain in the range of motion after the index procedure was 89 degrees in the patients treated with a hinge and 78 degrees in those treated without a hinge, an insignificant difference with the numbers available (p = 0.175). Complications associated with use of the hinge included five pin-track infections, one case of pin-track osteomyelitis, one ulnar fracture through a pin site, two broken Schanz screws, and two cases of irritation of the ulnar nerve. CONCLUSIONS: Open release of a severe elbow contracture results in a substantial gain in motion, with or without hinged elbow fixation. The slightly greater improvement in motion provided by the hinge does not justify the associated increase in risk, expense, and complications.

Adolescent↗