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At least 955 records · Page 53Linked to original sources
PubMed1989

External fixation versus traditional treatment for comminuted Colles fractures.

The results of conservative treatment of comminuted Colles fractures are discouraging. Due to this several different operative techniques have been presented by different authors for treatment of these injuries. Good results have been reported by external fixation, but this has usually been the "second line of defense" and has been applied only after conservative treatment has failed. The aim of the present study was to compare primary external fixation and conservative treatment for comminuted Colles fractures of type Frykman VIII. The study was designed as a prospective, controlled study.

Adult↗
PubMed1984

Stiffness of small-bone external fixation methods: an experimental study.

A variety of small-bone external fixation methods were evaluated to determine bending and torsional stiffness. Several methods of external pin stabilization with bone cement and with a commercial device were used. Among experimental variables examined were: the number of pins, pin diameter, pin length, pin spacing, and pin threading. The most rigid fixation was achieved with four pins held with a wire-reinforced bone cement fixator. Pin diameter was the most significant variable in the determination of stiffness with this configuration.

Animals↗
PubMed2003

An experimental two degrees-of-freedom actuated external fixator for in vivo investigation of fracture healing.

A novel two degrees-of-freedom external fixator that can accurately control interfragmentary mechanical conditions over an ovine tibial osteotomy is presented. The device can apply either axial or torsional motion, to investigate mechano-transduction mechanisms in fracture healing. The device was bench-tested over a range of gap stiffnesses, for its ability to apply pure axial or torsional motions, control interfragmentary strain magnitudes and to measure stiffness over the gap. The experiments reveal very little cross-coupling between axial and torsional displacements, although some transverse displacement occurs for both degrees-of-freedom. The mean interfragmentary strain can also be accurately controlled, but with some variation over the gap (due to coupled transverse displacement error). Interfragmentary stiffness measurements are accurate up to gap stiffnesses corresponding to bony bridging. This characterisation study has shown that the system is adequate to control and measure the mechanical conditions in a fracture healing experiment.

Animals↗
PubMed1995

Posttraumatic nonunion of the distal tibial metaphysis. Treatment using the Ilizarov circular external fixator.

Ten nonunions of the distal tibial metaphysis were treated by using the Ilizarov circular external fixator. Original fractures were classified in terms of the Association for the Study of Internal Fixation as AO type A (4 cases), type B (5 cases), and type C (1 case). Six patients had a history of osteomyelitis. Bifocal compression-distraction lengthening osteosynthesis was performed in all cases. Proximal metaphyseal corticotomy was combined with resection and compression of the distal nonunion site in five cases, and compression alone in three patients. Ankle arthrodesis, in addition to nonunion resection, was performed in two patients. Follow-up averaged 48 months (range, 26 to 81). Eight nonunions healed (80%). Limb length was completely corrected in five cases; angular and rotational alignment was corrected to within 5 degrees in seven patients (70%). Based on an objective and subjective scale, the results were considered good-to-excellent in seven cases and poor in three. Despite the high complication rate and relatively low success rate (70%), the use of the circular frame with small-diameter, tensioned wires may provide an alternative method for the treatment of the very difficult problems associated with complex low distal tibial metaphyseal nonunions.

Adult↗
PubMed2003

Placement of half-pins for supra-acetabular external fixation: an anatomic study.

An alternative location for placement of half-pins during pelvic external fixation is the dense supra-acetabular bone in the region of the anterior-inferior iliac spine. Although these fixators have gained popularity, to the authors' knowledge there are no studies evaluating the potential anatomic risks of placement of half-pins in this area; no safe corridors have been defined. Additionally, pins are placed near the hip capsule and no studies exist defining the superior extent of the hip capsule which potentially may be violated by placing half-pins in this location. The purposes of the current study were to evaluate the neurovascular risks and accuracy of fluoroscopically guided percutaneous placement of supra-acetabular half-pins, and to evaluate the anatomic superior extent of the hip capsule. Ten fresh frozen cadaveric pelves were used. A 5-mm half-pin was placed in the supra-acetabular bone under fluoroscopic guidance. Iliofemoral dissection was done and the proximity of the half-pin to local neurovascular risks was measured with a caliper. The hip capsule was exposed and the superior extent of the hip capsule was measured. Intraosseous pin placement was evaluated by direct observation. Nine pins were completely in bone, one had partially exited posteriorly and laterally. The lateral femoral cutaneous nerve was at risk with a mean distance of 10 mm (range, 2-25 mm) from the half-pins. The femoral nerve and femoral artery were not at risk. The average superior extent of the hip capsule was 16 mm above the joint (range, 11-20 mm). Half-pins can be placed accurately and safely in the supra-acetabular region using percutaneous techniques, appropriate soft tissue sleeves, and fluoroscopic guidance. Insertion of pins at least 2 cm above the hip is recommended to avoid potential hip capsule penetration.

Bone Nails↗
PubMed1984

External fixation for the uninfected angulated nonunion of the tibia.

External skeletal fixation is an effective method of stabilizing angulated ununited fractures of the tibia. In 14 patients who were not infected, realignment was accomplished by: closed-fracture-site manipulation (five cases); fibular osteotomy and closed manipulation (six cases); or fibular osteotomy and open reduction (three cases). External fixation was selected instead of internal fixation for patients in whom there was: risk of reactivating quiescent sepsis; thin secondary epithelium adherent to bone that might slough after surgical dissection; a very proximal or a very distal nonunion, where internal fixation is technically difficult; or a bulky, angulated delayed union or nonunion or one in bayonet apposition that would require excessive plate contouring. On the average, patients were corrected from 17.3 degrees (either varus or valgus) to 2.3 degrees. Two patients did not unite with the fixator/orthosis treatment plan, but neither one lost correction during subsequent management. The technique is not suitable for atrophic nonunions.

Adolescent↗
PubMed1995

Articulated external fixation of pilon fractures: the effects on ankle joint kinematics.

The effect of the Orthofix articulated ankle external fixator on ankle and subtalar joint kinematics and fracture fragment motion was investigated in fresh cadaver specimens using biplanar radiographic analysis. The kinematic testing was performed for the normal ankle (i.e., no fixation) and for three alternate fixator hinge orientations. The fixator applications simulated a horizontal ankle axis (the current clinically preferred orientation), an axis coincident with a previously defined approximate ankle axis, and an axis located using a mechanical axis finder. The horizontal fixator application significantly disturbed normal ankle kinematics. Aligning the fixator hinge with an approximate ankle axis caused significant distortion of motion about only two of six possible rotational axes. Aligning the fixator hinge with the (specimen-specific) ankle axis determined by the axis finder most closely matched the motion of the normal ankle. For pilon fractures simulated by a transverse osteotomy, there appeared to be no physiologically significant fracture fragment motions, regardless of fracture stability or fixator orientation.

Ankle Injuries↗
PubMed1995

External fixation for tibial fractures: clinical results and cost effectiveness.

We report our experience with the Orthofix external fixator in the management of closed and Gustilo grades 1 and 2 compound unstable tibial shaft fractures. Forty-four fractures were treated between January 1988 and December 1989. All the fractures united. Median time in hospital was 13 days. Median time to union was 21 weeks for closed and 22 weeks for compound fractures. A method of estimating the overall cost per patient is described. Using this method we compared the cost of using the Orthofix with that of intramedullary nailing and plating according to AO principles. The Orthofix fixator was cheaper than alternative methods in particular because no readmissions were required for implant removal.

Adolescent↗
PubMed1989

Chinese external fixation treatment for fractures of the distal end of the radius.

One hundred forty-five patients with fractures of the distal end of the radius (age range, 13 to 76 years; means, 61 years) were treated conservatively with a Chinese system of external fixation. Most of the fractures were of the extension and extraarticular type. The fixation system consists of four splints used in conjunction with three pressure pads and three or four slings. The system was used after successful manipulative reduction, and the patients were instructed to move their joints as soon as possible. The results, especially in elderly patients, were highly encouraging. We believe that this Chinese system of external fixation serves as a kind of functional brace.

Adolescent↗
PubMed1988

Severe open tibial fractures. Results treating 202 injuries with external fixation.

Grade III open tibial fractures are known for frequent complications and poor clinical results, yet published series are few and cite conflicting results. To address this dilemma, the authors report a prospective study of 202 consecutive Grade III tibial fractures. All injuries were treated under protocol at the authors' university with primary external fixation and serial debridement. Equinus deformity was prevented with a new tibiometatarsal frame extension. Severe injuries crossing the ankle or knee were temporarily stabilized with external fixation across these joints. Staged reconstruction of soft tissue and then bone was undertaken for 176 of these tibias in patients who survived their multiple injuries. Reconstructive procedures included skin grafts in 57%, muscle flaps in 32%, and bone grafts in 28%. Gastrosoleus myocutaneous flaps were successful in 92% of cases versus 66% for free flaps. Late follow-up data were obtained for 171 (97%). Infection occurred in 15% and led to amputation in 7%. The infection rate was reduced to 9% in the second half of the series largely by removal of all necrotic bone prior to wound coverage. Angulation (greater than 10 degrees) in 9% and delayed union were lessened with early posterolateral grafting followed by progressive fracture loading in the fixator. A 9% incidence of pin tract drainage or loosening was reduced with predrilling and diaphyseal half pins. The time to fixator removal averaged 87 days. Ninety-three percent of the fractures united (median time, nine months) but healing times varied widely according to the amount of tissue injury and bone loss. Eighty-nine percent had satisfactory late clinical function. Results from this study, the largest series of open Grade III tibial fractures reported to date, suggest that successful staged reconstruction is now a reasonable expectation for most of these severe injuries.

Adolescent↗
PubMed1995

Alternative external fixation for open fractures of the lower leg.

A locally made cheap external skeletal fixator using wood and its use in seven patients with an open fracture of the lower leg together with soft-tissue injury are described. The application of the external fixator in such fractures is a good example of appropriate technology and facilitates the daily hygienic nursing care of wounds.

Adolescent↗
PubMed1991

Comminuted fractures of the basilar joint of the thumb: combined treatment by external fixation, limited internal fixation, and bone grafting.

Displaced, comminuted fractures of the thumb carpometacarpal joint were treated by intermetacarpal external fixation, anatomic reduction of the joint surfaces, bone grafting and adjunctive internal fixation in thirteen patients. Retrospectively, at an average follow-up time of 35 months, nine patients showed a good result and one patient had a fair result. All fractures had united without secondary displacement, but focal irregularities of the joint surface were commonly seen. As compared with the uninvolved side, axial rotation averaged 79%, radial abduction 89%, key pinch 88%, and grip strength 81%.

Adolescent↗
PubMed2002

Medium-term results of trapezio-lunate external fixation for scaphoid fractures.

We treated 36 scaphoid fractures in 34 patients with trapezio-lunate external fixation. According to the Herbert and Fisher classification, there were 16 type B1, 14 type B2, four type B3 and two type B4 fractures. Trapezial and lunate pins broke in three patients and these were rated as failures. The remaining 33 fractures were followed-up for 3 years and all had excellent outcomes, without signs of arthritis, avascularity or instability.

Adolescent↗
PubMed2003

External fixation or arteriogram in bleeding pelvic fracture: initial therapy guided by markers of arterial hemorrhage.

BACKGROUND: Bleeding pelvic fractures (BPF) carry mortality as high as 60%, yet controversy remains over optimal initial management. Some base initial intervention on fracture pattern, with immediate external fixation (EX FIX) in amenable fractures aimed at controlling venous bleeding. Others feel ongoing hemodynamic instability indicates arterial bleeding, and prefer early angiography (ANGIO) before EX-FIX. Our aim was to evaluate markers of arterial bleeding in patients with BPF, thus identifying patients requiring early ANGIO regardless of fracture pattern. METHODS: Patients with pelvis fracture were identified from a Level I trauma center registry over a 7-year period and records reviewed. From this group, two subsets were analyzed: those with initial hypotension related to pelvic fracture, and those without hypotension who underwent pelvic ANGIO. Data included hemodynamics, response to resuscitation, presence of contrast blush on CT, fracture treatment and outcome. Adequate response to initial resuscitation (R) was defined as a sustained (>2 hours) improvement of systolic blood pressure to >90 mm Hg systolic after the administration of < or = 2 units packed red blood cells. Those with repeated episodes of hypotension despite resuscitation were classified as non-responders (NR) RESULTS: From 1/94-1/01, 1171 patients were admitted with pelvic ring fracture. Thirty-five (0.3%) had hypotension attributable to pelvis fracture. 28 fell into the NR group, and 26 of these underwent ANGIO. Nineteen (73%) showed arterial bleeding while 3 resuscitation response patients underwent ANGIO with none demonstrating bleeding (p = 0.03). Sensitivity and specificity of inadequate response to initial resuscitation for predicting the presence of arterial bleeding on ANGIO were 100% and 30% respectively while negative and positive predictive value were 100% and 73%. In patients with fractures amenable to external fixation (n = 16), 44% had arterial bleeding on ANGIO, and all were in the NR group. An additional 17 patients without hypotension also underwent ANGIO. Contrast blush on admission CT was seen in 4, 3 of which had arterial bleeding seen on ANGIO (75%). Sensitivity and specificity for contrast blush in predicting bleeding on ANGIO were 60% and 92% with positive and negative predictive value being 75% and 85%. CONCLUSIONS: In patients with hypotension and pelvic fracture, therapy selection based on initial response to resuscitation in BPF yields a 73% positive ANGIO rate in NR patients. Delay in ANGIO for EX FIX in patients with amenable fractures would have delayed embolization in the face of ongoing arterial bleeding in 44% of patients. In stable patients with pelvic fracture, contrast blush also indicates a high likelihood of arterial injury and ANGIO is indicated. Optimal therapy in the face of BPF requires early determination of the presence of arterial bleeding so that ANGIO can be rapidly obtained, and response to initial resuscitation as well as the presence of contrast blush aid in this decision.

Adult↗
PubMed1994

[A new open universal clamp for the external fixator tube system of the AO].

A new open universal clamp has been developed for the external fixator tube system of the ASIF. This new clamp is fully compatible with the previous system. All mechanical properties are at least comparable with those of the hitherto successful clamps, whereas in some cases they are even distinctly superior. The obvious advantages are: The clamp can also be pushed subsequently laterally onto the tubes and arbon fibre rods. The clamping plate for the Schanz screws can take 4-6 mm screws. It is thus possible to use this system alongside with the 4 mm system. The clamp replaces 2 of the previous clamps. An open tube-to-tube clamp can also be positioned. The clamps have been used with success and with full utilisation of all their advantages in their first clinical application.

Biomechanical Phenomena↗
PubMedDate not supplied

[Current trends and problems in the measurement of limb loading parameters during transosseous osteosynthesis using external fixation devices].

The problem in question is whether it is reasonable to equip a conventional limb external fixation apparatus with means for the diagnosis of loading parameters: the forces and displacement of the opposite supporting elements of the apparatus. It is assumed that during distraction osteogenesis it is expedient to apply load to the limb by the load rate only at the initial stage of callus regeneration (the plastic or slightly elastic mechanical state) while the most effective way to do so is to act force at later stages. A number of functions derived from the modified parameters which might aid a physician to choose the optimum limb loading parameters at different stages of treatment were considered by using as example a hypothetical ring-type apparatus equipped with means for continuous measurement of current forces applied to the apparatus and current displacements of opposite ring blocks. Specifications for the measuring system of loading parameters were defined by using an Ilizarov apparatus as an example and why possible rough measurement errors may occur is revealed. The paper shows it necessary to develop methods for calculation of parasitic deformations, i.e. those of the loaded elements of the apparatus for the evaluation of the reciprocal displacement of bone fragments.

Biomechanical Phenomena↗
PubMedDate not supplied

Tension wire position for hybrid external fixation of the proximal tibia.

OBJECTIVE: To compare a new configuration of proximal wires for hybrid external fixation with the standard configuration. DESIGN: Biomechanical testing of five matched pairs of fresh cadaveric tibia. INTERVENTION: The authors compared the standard tension wire configuration of the three proximal wires with a more sagittal orientation of the oblique wires. A second study compared the new configuration with two wires and an offset half-pin. A two-centimeter segmental defect was created just distal to the tibial tubercle and the tibias fixed in a Montecelli Spinelli (Howmedica, NJ, U.S.A.) hybrid frame. The constructs were biomechanically tested using an Instron servohydraulic biaxial testing machine. RESULTS: There was a significant 67 percent decrease in displacement during anterior posterior bending and a significant 40 percent decrease in displacement in posterior bending with the new configuration compared with the standard configuration (p < 0.05). The differences in stability in all other testing modes were not significant. There was no significant difference between the new configuration and the two wire and off-set half-pin configuration. CONCLUSION: We recommend anterior placement of the oblique tension wires in the proximal tibia to more effectively resist bending in the sagittal plane, which is the most common deforming force on proximal metaphyseal fractures.

Biomechanical Phenomena↗
PubMed1999

External fixation for open proximal ulnar fractures.

We describe our experience with the use of a pyramidal configuration external fixator in the management of open fractures of the proximal ulna. A prospective study was conducted. 21 patients with open fractures of the proximal ulna (Gustilo-Anderson Grade II and III A) were treated by the application of a new fixator frame. The soft tissue injury was managed with the help of the plastic surgeons. All the patients were followed up clinically and radiologically for a total duration of 3 years after the injury. They were rated on a combined objective and subjective assessment scale by an independent observer. All the patients were rated as good to excellent at the end of a 3 year follow up. The main advantages were simplified wound care and ease of supplementary plastic procedures. No vascular or neurological complications were encountered. The average time taken for union with the fixator was 9 weeks. All the fractures united well. Mobility and function of the elbow were preserved in all cases.

Adolescent↗