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At least 991 records · Page 55Linked to original sources
PubMed2003

The incidence of neurovascular injury during external fixator placement without radiographic assistance for lower extremity diaphyseal fractures: a cadaveric study.

BACKGROUND: During military operations or mass casualty situations, trauma surgeons are called on to place external fixation without the use of fluoroscopy. However, the safety and efficacy of this procedure has not been investigated. METHODS: Orthopedic surgeons, with varying experience, externally stabilized 20 fractured cadaver femora and tibiae. Using Behrens' safe zones, 194 half-pins were placed without radiographic assistance. Subsequently, fluoroscopy and dissections documented pin positions. RESULTS: Of the 194 pins, there were three (1.5%) neurovascular injuries (popliteal artery trifurcation). Forty-nine percent (95 of 194) of pins were overpenetrated (greater than two threads out the second cortex), with the mean distance to neurovascular structures of 10.2 mm. The mean overpenetration was +5.2 threads (13 mm). CONCLUSION: When compared with radiography-assisted fixation, our results show the risk for neurovascular injury doubles with pin placement without fluoroscopic assistance. At less than 2%, this may be an acceptable rate in battlefield/mass casualty situations. This study also demonstrates that increased experience with standard fixation correlates to safer pin placement feel-placed fixation. In austere conditions, experienced surgeons can safely place external fixators without radiographic guidance.

Bone Nails↗
PubMed2001

CMC external fixator.

PURPOSE OF THE STUDY: Imobilisation of wounded extremity decreases pain and shock, diminishes the possibilities of soft tissue, vessels and nerves injury with bone fragments, that influences the volume and success of surgical debridement of the wound. Optimal external fixator for war purposes must be rigid in construction, have to be simple to master, allow simple approach to wound during the whole period of fixation, have to be in sterile package with all its necessary part and should not be too expensive. DESIGN OF THE STUDY: Prof. Korzinek in correspondence with "Instrumentarija" from Zagreb developed a new type of external fixateur applicable in war situation and natural disasters. It was named CMC (Croatian Medical Corps) external fixateur, and it ensures imobilisation of extremity during transport to area of final treatment and it could also ensure conditions for definitive fixation. CMC is compound of bar, clamps and Schanz screws. Standard packing are CMC-30 and CMC-40. CONCLUSION: CMC external fixator is the applicable device in war and natural disaster situations. It is simple to master even for less experienced surgeons, it's low volume allows appropriate wound treatment, it could be resterilised and reused and it has acceptable price.

Croatia↗
PubMed2005

Development and validation of a new approach for computer-aided long bone fracture reduction using unilateral external fixator.

An innovative computer-aided method to plan and execute long bone fracture reduction using Dynafix unilateral external fixator (EF) is presented and validated. A matrix equation, which represents a sequential transformation from proximal to distal ends, was derived and solved for the amount of rotation and translation required at each EF joint to correct for a displaced fracture using a non-linear least square optimization method. Six polyurethane-foam models of displaced fracture tibiae were used to validate the method. The reduction accuracy was quantified by calculating the residual translations (xr, yr, zr), the residual displacement (dr), and the residual angulations (alphar, betar, gammar) based on the X-Y-Z Euler angle convention. The experiment showed that the mean+/-S.D. of alphar, betar, gammar, xr, yr, zr and dr were 1.57+/-1.14 degrees, 1.33+/-0.90 degrees, 0.71+/-0.70 degrees, 0.98+/-1.85, 0.80+/-0.67, 0.30+/-0.27, and 0.50+/-0.77 mm, respectively, which demonstrated the accuracy and reliability of the method. Instead of adjusting the fixator joints in-situ, our method allows for off-site adjustment of the fixator joints and employs the adjusted EF as a template to guide the surgeons to manipulate the fracture fragments to complete the reduction process. Success of this method would allow surgeons to perform fracture reduction more objectively, efficiently and accurately yet reduce the radiation exposure to both the involved clinicians and patients and lessen the extent of periosteum and soft tissue disruption around the fracture site.

Bone and Bones↗
PubMed1992

False aneurysm of the anterior tibial artery in lower leg fractures treated with the Ilizarov external fixator. Case report.

A case of open segmental fracture of the right lower leg treated with an Ilizarov external fixator in emergency surgery is presented. Approximately two months after operation, swelling in the anterior compartment of the tibia and repeated episodes of bleeding from one of the Kirschner wire holes led the authors to perform an angiography, which revealed the presence of a false aneurysm of the anterior tibial artery. The intraoperative finding of a double lesion in the anterior tibial artery confirmed the iatrogenous nature of the injury.

Aged↗
PubMed1983

Osteosynthesis of fractures of the base of the first metacarpal by an external fixator.

Among the various methods for treating fractures of the base of the first metacarpal, use of the external fixator appears to be of interest for it maintains a satisfactory reduction while respecting the arch of the first web interspace as well as allowing early mobilization of all joints not involved in the injury. The miniaturization of the material, today possible, facilitates its use. The experience with 20 cases gained at the CTO de la CRAM de Strasbourg is presented. The authors discuss the utilization of the method, the practical means of doing it and their results. Its limitations are indicated as well as its special indications in comminuted and compound fractures.

Adolescent↗
PubMed2006

External fixation for displaced intra-articular fractures of the calcaneum.

A minimally-invasive procedure using percutaneous reduction and external fixation can be carried out for Sanders' type II, III and IV fractures of the os calcis. We have treated 54 consecutive closed displaced fractures of the calcaneum involving the articular surface in 52 patients with the Orthofix Calcaneal Mini-Fixator. Patients were followed up for a mean of 49 months (27 to 94) and assessed clinically with the Maryland Foot Score and radiologically with radiographs and CT scans, evaluated according to the Score Analysis of Verona. The clinical results at follow-up were excellent or good in 49 cases (90.7%), fair in two (3.7%) and poor in three (5.6%). The mean pre-operative Böhler's angle was 6.98 degrees (5.95 degrees to 19.86 degrees), whereas after surgery the mean value was 21.94 degrees (12.58 degrees to 31.30 degrees) (p < 0.01). Excellent results on CT scanning were demonstrated in 24 cases (44.4%), good in 25 (46.3%), fair in three (5.6%) and poor in two (3.7%). Transient local osteoporosis was observed in ten patients (18.5%), superficial pin track infection in three (5.6%), and three patients (5.6%) showed thalamic displacement following unadvised early weight-bearing. The clinical results appear to be comparable with those obtainable with open reduction and internal fixation, with the advantages of reduced risk using a minimally-invasive technique.

Adult↗
PubMed1992

Evaluation of linear finite-element analysis models' assumptions for external fixation devices.

Linear finite-element models (FEMs) have enjoyed an increased use in orthopaedic research, including the use for modeling external fixation devices. These fixator FEMs depend on a number of basic assumptions concerning the overall fixation frame stability and the components' rigidity. Among the more important ones are: (i) rigid fixation at both ends of the pin and sidebar; (ii) that the sidebar can be treated essentially as a rigid entity, with all bending occurring in the bone pins; and (iii) that the system can be treated as linearly elastic. Prior work done by the authors questions some of these assumptions. Thus, this study sought an empirical evaluation of the validity of some of these a priori assumptions. A Hoffmann single half-frame was tested in its standard form and then according to a stepwise protocol wherein the frame was welded to eliminate any possible points of instability. These tests looked at the stability and rigidity in various modes (axial compression, torsion, and medial-lateral and anterior-posterior four-point bending). The basic assumptions concerning the frame stability, frame rigidity and the frame's response to loads were found to be erroneous. Component failure was common under minimal loads and statistically significant differences (p less than 0.05) of up to 75% were noted in frame rigidity among the various frame forms tested. Thus, considerable caution must be exercised when employing the FEM technique for evaluating the fixator properties.

Biomechanical Phenomena↗
PubMed2006

The effects of silver coated external fixation pins.

We performed a randomized controlled trial in order to assess the effect silver coating of an external fixator pin has on pin infection. The experimental silver coated pins (SC) were compared to control stainless steel (SS) pins. A clamp design monolateral fixator was used, and pins were randomized to clamp position to allow side-by-side comparisons of pins in a similar environment. Nineteen patients and 33 clamps were entered and completed the study. There were no significant differences between the two types of pins in the rate of pin tract infection, clinical appearances of the pin sites, bacteriology of the pin tracts, torque to remove the pins, or radiographic lucency around the pin. We concluded that with the numbers available in this study, there were no detectable differences between the performance of SC and SS pins.

Adolescent↗
PubMed2004

The accuracy of fine wire tensioners: a comparison of five tensioners used in hybrid and ring external fixation.

OBJECTIVES: To compare the accuracy of 5 commonly available fine wire tensioners used in hybrid and ring external fixation. DESIGN: A laboratory investigation. SETTING: The testing of 5 commonly available tensioners was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). MAIN OUTCOME MEASUREMENT: The real wire tension data of each tensioner provided by the MTS were compared with corresponding nominal values. The percent error for each tensioner was calculated. Clinical ease of usage of the wire tensioners was also evaluated. RESULTS: The EBI tensioner was the most accurate (-0.17% to 0.09% error). The Smith and Nephew tensioner had a -13.97% to -8.61% error, the How medica tensioner a -12.48% to -10.86% error, and the Synthes tensioner a -0.2% to 24.28% error. The DePuyACE tensioner was the least accurate, with errors ranging from -36.76% to -30.92%. The Howmedica tensioner was the easiest to use, followed by the Smith and Nephew tensioner, the DePuyACE tensioner, the Synthes tensioner, and the EBI tensioner. CONCLUSIONS: Most commonly available tensioners tend to undertension. Future efforts should focus on the development of wire tensioners that combine accuracy and ease of usage.

Bone Wires↗
PubMed1995

Strength of the pin-bone interface of external fixation pins in the iliac crest. A biomechanical study.

The iliac crest is a frequent insertion site for external fixation pins in treating unstable pelvic or acetabular fractures and in iliofemoral distraction for superiorly dislocated hips. The pin-bone interface is critical for the success of treatment, but studies of the iliac crest are lacking. The purpose of this study was to investigate the strength of the pin-bone interface of different pins and different insertion methods. Four types of commercial pins, Wagner pins, Orthofix cortical and cancellous screws, and AO pins, were driven into sheep iliac crests by 2 methods: the intercortical and the transcortical. Specimens were tested for pullout and bending with an Instron testing machine (Model 1343) at a extension rate of 0.02 mm/sec to failure. The results revealed that the intercortical method had a stronger pullout force than the transcortical in all types of screws (p < 0.05), probably caused by longer insertion in the bone. In the pullout tests, the Wagner pins were the strongest and the Orthofix cancellous screws were the weakest. There were no differences in bending. In the iliac crest, the intercortical method was the better way of driving pins, and the new Orthofix screws were not proven to be stronger than the Wagner pins, nor were the cancellous screws more suitable than the cortical ones.

Animals↗
PubMed1999

Use of Ilizarov external fixation for a periprosthetic supracondylar femur fracture.

Supracondylar femur fractures above a total knee replacement are rare injuries that may be challenging to treat. We present a case of an elderly woman whose supracondylar femur fracture was not deemed amenable to conventional treatment. This patient underwent fixation of her femur fracture above a total knee replacement using an Ilizarov external fixator. The fixator was removed at 10 weeks, at which time the fracture was solidly healed. At the most recent follow-up, the patient is 19 months postinjury. She is fully weight bearing without walking aids and has a knee range of motion of 0 degree to 110 degrees.

Aged↗
PubMed1988

Experiences with external fixation with emphasis on the complications.

A series of 157 external skeletal fixations carried out in 135 patients was retrospectively studied with special attention to related complications like incorrect placement of pins, pintrack infections, instability, fistulisation or osteitis. Complications were seen in 31 procedures, eight of these were more or less serious. The results show that external fixation, though indispensable for the treatment of various skeletal affections, is associated with a considerable high risk of complications.

Bone Nails↗
PubMed1996

[Treatment of distal forearm fractures using external fixation].

The author presents a group of 37 patients with fractures of the forearm treated by the method of external fixation. Mostly closed fractures of the distal radius were involved which could not be stabilised conservatively by plaster fixation. The method was however also used in open fractures of the forearm and pseudoarthroses at this site. Practically always a closed reposition of the fracture was made, in some cases supplemented by percutaneous transfixation of an unstable fracture by a Kirschner wire.

External Fixators↗
PubMedDate not supplied

Rail external fixation for stabilization of closing base wedge osteotomies and lapidus procedures: a retrospective analysis of sixteen cases.

This is a retrospective study of 16 cases of proximal first-ray procedures with rail external fixation. Arthrodesis of the first metatarsal-cuneiform joint was performed on 11 feet, and a closing base-wedge osteotomy was performed on 5 feet. Heel weightbearing in a surgical shoe with ankle joint mobilization was the standard postoperative protocol. Thirteen women and one man with an average age of 41 years (range, 16-64 years) were evaluated, with an average follow-up of 15.12 months (range, 10-24 months). The mean duration of frame application among all patients was 6.75 weeks (range, 2-10 weeks; 7 weeks for the base wedge procedures; 6.64 weeks for the lapidus). Multiple complications developed. Ten patients developed pin-tract infections: 5 required isolated pin removal, whereas 2 required removal of the entire frame because of the severity of infection. Seven patients developed pin loosening. Two patients developed cellulitis requiring long-term intravenous antibiotic therapy. Two nonunions occurred, both with the lapidus procedure, and one was symptomatic. Ten of the 16 patients reported they would have surgery again. Monolateral external rail fixation in combination with heel weightbearing and ankle mobilization demonstrated a high complication rate when used for proximal first-ray procedures. The technique as described is not recommended for routine use with the lapidus and base wedge osteotomy procedures.

Adolescent↗
PubMed1994

Biomechanical analysis of a new external fixation system and its clinical significance.

The present study was conducted to analyze the biomechanical properties of a new external fixation system. Each frame was tested in compression, tension, and four-point bending and compared under similar conditions with the performance of the standard configurations of the Orthofix, Hoffmann, and AO models. With the new model we are able to create frames of variable rigidity, both higher and lower than that of the commercially available models. It was also possible to change the rigidity of the new frame as the fracture healed without losing the stability of the fracture. This study demonstrated that the new design, with its simplicity, versatility, and modularity, has sound biomechanical properties and these compare well with the clinical success that the model has achieved during trials.

Biomechanical Phenomena↗
PubMed2002

Overgrowth and correction of rotational deformity in 12 femoral shaft fractures in 3-6-year-old children treated with an external fixator.

We treated 11 young children (3-6 years old) who had uncomplicated femoral shaft fractures primarily with an external fixator. 9 children were available for follow-up and were evaluated for the amount of overgrowth and rotational deformity. All underwent a clinical examination and an MRI after mean 21 (13-25) months. The mean overgrowth was 0.4 (-0.3-1.1) cm and the anteversion angle showed a mean increase of 12 degrees, as compared to the contralateral femur. In 5 children with an anteversion angle difference of 10 degrees or more, a second MRI was done 4 years after the trauma. The mean anteversion angle difference of the femora in these 5 children had diminished from 15 degrees on the first MRI to 7.4 degrees on the second. 3 of the 5 children had a full correction of their rotational deformity. Growth did not correct the rotational deformity in the oldest child in this group.

Child↗
PubMed1994

Anatomic and radiographic considerations in the placement of anterior pelvic external fixator pins.

Anatomic and radiographic studies were performed on three cadaveric pelves to define recommendations for better anterior pelvic external fixator pin placement. A thick zone of bone was identified for pin purchase beginning along the iliac crest 2-3 cm posterior to the anterior superior iliac spine (ASIS), and extending 6-8 cm posteriorly along the crest. This zone is hourglass-shaped, and follows the superior gluteal ridge to the superior acetabular region. This zone has a maximal thickness of 4 cm in the supra-acetabular region, and a minimum of 8 mm at the isthmus. Cortical pin penetration is more likely to occur if pin placement begins in the lateral third of the iliac crest, or if the pin is advanced beyond the isthmus of this zone, 5 cm from the crest. Acetabular penetration occurs when the pins are advanced farther than 10.5 cm. Radiographic evaluation demonstrates that only the pelvic outlet view gives the proper orientation of the iliac tables to guide the angle of the pin placement (24 degrees from vertical) and to confirm proper pin placement. Computed tomography (CT) evaluation with "inlet" positioning of the gantry gives complementary information for pin placement.

Bone Nails↗