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Results for “Internal Fixators”

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At least 37 records · Page 2Linked to original sources

PubMed1980

The use of immediate internal fixation in open fractures.

Internal fixation of open fractures can be carried out according to the same indications employed in closed fractures in the presence of a type I wound. In type II and type III wounds early internal fixation may be indicated in victims of multiple trauma, in the elderly, in intra-articular fractures, in mutilated limbs, and in some fractures with associated vascular injuries. In these cases the higher risk of infection should be justified by the salvage of limb, life, or joint function. The risk of infection can be minimized by meticulous irrigation and debridement of the fractures, atraumatic surgical technique, and rigid fixation and by leaving the wound open.

Adolescent↗

PubMed1988

Rigid internal fixation for fractures involving tooth-bearing maxillary segments.

Fracture dislocations of the middle third of the face usually involve a complex combination of the three types of fractures initially described by LeFort. Treatment of these injuries requires a six- to eight-week period of intermaxillary fixation, unless rigid internal fixation devices (plates and screws) are used to stabilize the fractures. However, rigid fixation carries the risk of producing a malunion and serious malocclusion if not performed correctly. A review of 22 patients with complex LeFort fractures treated with rigid fixation revealed that the only absolute contraindication to its use is difficulty in interdigitating the maxillary and mandibular teeth in a passive fashion at the time of fracture reduction. Rigid internal fixation should therefore be considered as an alternative treatment for most fractures of the middle third of the face.

Fracture Fixation, Internal↗

PubMed1989

Update-1988. Current status of internal fixation of thoracolumbar fractures.

Rigid internal fixation has become the preferred method of treatment for unstable thoracolumbar fractures in most American spine centers. In most cases, posterior instrumentation alone is adequate, but occasionally an anterior procedure is necessary. A number of internal fixation devices are now available to the orthopaedic surgeon. Controversy exists regarding the number of levels that need to instrumented and the optimal form of internal fixation.

Adult↗

PubMed1989

The AO spinal internal fixator.

The AO spinal internal fixation system uses 5.0 mm diameter transpedicular Schanz screws with 7.0 mm diameter fully threaded stainless steel rods. Originally developed for the treatment of thoracolumbar and lumbar spine fractures, it can be used for a variety of spinal disorders. A prospective study has been carried out, and the first 48 patients have been reviewed. The results for those patients with fractures are excellent. In burst fractures, it has been possible to decompress the canal and restore lordosis. In only half of the cases of spondylolisthesis has it been possible to improve the degree of slip. The fixator has provided rigid stabilization for a variety of other spinal problems.

Adolescent↗

PubMed1977

Mechanical stability and post-traumatic osteitis: an experimental evaluation of the relation between infection of bone and internal fixation.

Stable and unstable internal fixation of fractures was performed in rabbits. After inoculation with Staphylococcus aureus, clinically manifest osteitis occurred only in the very unstable fractures. Abscesses, sinuses and sequestra developed in 45 per cent of the unstable fractures, whereas clinically manifest osteitis did not occur after rigid fixation. With rigid fixation there was no significant difference in the time to bony union between the infected and uninfected fractures. It seems that the development of osteitis and the healing of a fracture are both related to the degree of rigidity, but remain independent of each other. The significance of these findings in the management of posttraumatic osteitis is discussed.

Animals↗

PubMed1981

Use of a dynamic mini-compression plate for the internal fixation of mandibular fractures.

Internal fixation for mandibular fractures can be simplified using dynamic mini-compression bone plates, frequently employed by orthopedic surgeons. These enable fragment immobilization without the usual intermaxillary fixations--arch bars, splints, and so on. They also allow better oral hygiene, early feedings, and short hospitalization. Complications and risk of infection appear to be minimal. The intraoperative steps are described.

Biomechanical Phenomena↗

PubMed1986

Management of mandibular trauma with rigid internal fixation.

The use of rigid internal fixation has become an acceptable method for the treatment of fractures and continuity defects of the mandible. This technique has a wide variety of applications, including stabilization of mandibular segments for the application of bone grafts. The primary advantage of rigid fixation is that it obviates the need for maxillomandibular fixation associated with the treatment of mandibular trauma by traditional methods. This article reviews twenty cases in which rigid internal fixation was used for the treatment of fractures and continuity defects of the mandible. In only one case was early removal of the implant necessary as a result of infection.

Adult↗

PubMed1988

[Cross stabilization of the internal fixator of the spine].

The "Internal Fixator" for stabilizing the dorso-lumbar spine represents an effective and meanwhile established device to neutralize flexion-bending and sagittal shearing forces. Because of the possible movement of the Schanz' screws in the bone and within the connection clamps, this device does not withstand torsional and frontal plane shearing forces after postinjury or postlaminectomy instability. Therefore, a cross-link device, adaptable to the "Internal Fixator" has been developed. Biomechanical testing against torsion and frontal plane bending moments have shown very low stability resulting in lateral displacement of the fixation device without cross-linking. The diagonal bracing with two wire cerclages does not significantly increase the stability. The recently developed cantilever cross-link device completes the two longitudinal bars to a frame construction and increases therefore the torsional and frontal plane stability for over 70%. This supplementary device is easy to apply to the "Internal Fixator" and has been successful in clinical practise.

Biomechanical Phenomena↗

PubMed1991

Biomechanical evaluation of a biodegradable composite as an adjunct to internal fixation of proximal femur fractures.

Internal fixation of comminuted unstable fractures of the severely osteoporotic proximal femur is sometimes supplemented with polymethyl-methacrylate (PMMA). We here report an in vitro biomechanical evaluation of a biodegradable particulate composite that might be used for similar purposes. The composite includes a matrix phase consisting of a hydrolyzable prepolymer [polypropylene fumarate (PPF)] cross-linked with methacrylate monomer, and a particulate phase consisting of tricalcium phosphate and calcium carbonate. We implanted dynamic hip screws in 22 cadaveric proximal femora and measured the yield load for an oblique force applied to the femoral head. The hip screws were then reinforced with either PMMA or the PPF composite and tested again. On the basis of analysis of variance, the average increases in yield load for PMMA and PPF reinforcement of 1,750 and 1,130 N were statistically significant (p less than 0.00005), suggesting that both materials enhance congruence between implant and bone and thereby increase the projected load-bearing area of the implant. The increase in yield force with PMMA was slightly higher than the increase with PPF (p less than 0.05), but both values after reinforcement were close (3,790 +/- 561 N for PMMA vs. 3,240 +/- 669 N for PPF). If we can demonstrate that appropriate rates of degradation, bony ingrowth, and static and fatigue properties can be achieved in vivo with this system, our data suggest that this PPF composite may have potential as an adjunct to the internal fixation of unstable fractures of the osteoporotic hip.

Aged↗

PubMed1984

The comparative strengths of internal fixation techniques.

The strengths of internal fixation techniques have been compared by transecting human cadaver metacarpals, reducing and fixing the fractures, and then applying forces to mechanically bend the bone during simulated flexion. Kirschner wires alone, intraosseous wire loops with and without Kirschner wires, and bone plates were tested. Intraosseous loops were tested in three configurations, each with four different wire gauges. Intraosseous loops were stronger than Kirschner wires. Right-angle loops were the best of the intraosseous configurations. The addition of a Kirschner wire strengthened the best dorsopalmar intraosseous loops but not the best right-angle loops. Dorsal bone plates were comparable with the best intraosseous loop configurations of 26-gauge wire.

Fracture Fixation, Internal↗

PubMed1990

Fixation of mandibular fractures: a comparative analysis of rigid internal fixation and standard fixation techniques.

This study used a prospective design to compare standard therapy (closed or open reduction with 4 weeks of maxillomandibular fixation) to rigid internal fixation (RIF) for the treatment of mandibular fractures. Ninety-two patients with 143 fractures were evaluated and treated. There was no statistically significant difference in the treatment results between the two groups, despite a bias in the distribution of study variables that favored the standard therapy.

Adult↗

PubMed1993

Complications associated with rigid internal fixation of facial bone fractures.

Rigid internal fixation is now a common method for treating fractures of the facial skeleton. However, it is a very precise technique that requires more time than intraosseous wiring. This article reports the complications associated with rigid internal fixation of facial fractures in 223 patients and compares the findings with those accompanying intraosseous wiring.

Bone Plates↗

PubMed1989

[Transversal fracture of the patella: experimental evaluation of the Lotke and Ecker method of internal fixation].

Four different methods of internal fixation of transverse fractures of the patella were experimentally evaluated in eight cadaver knees: circumferential wiring, tension band cerclage, cerclage over Kirschner wires and the Lotke's method. Linear and angular displacements were accurately measured by means of a micrometer while actively extending the knee from 90 degrees of flexion to full extension. Circumferential wiring gave the highest displacements, up to 25 mm at 30 degrees of flexion on average. Tension band cerclage showed much better results but the greatest stability was obtained with the cerclage over Kirschner wires and with the Lotke's technique which yielded displacements of less than 1 mm. These last two methods combine the tension band principle and transosseous fixation, which are both essential to obtain a stable fixation.

Evaluation Studies as Topic↗

PubMed1979

Experimental study on internal fixation of femoral neck fractures.

The relative strength and the failure mode of internal fixation by multiple pinning and nailing was investigated on 35 specimens. Internal fixation consisted of 3, 5 and 7 Knowles pins, a Smith-Petersen nail or a sliding nail plate. The strength of a specimen with a triflanged nail is only half of that with multiple Knowles pins. There is no significant difference in strength of 3, 5, or 7 pin specimens. The strength of an internal fixation with a sliding nail plate is not superior to the strength of multiple pinning. The mode of failure for the different types of internal fixation is primarily a crush fracture of the supporting trabecular bone at the femoral neck with downward and outward migration of the pins or nail. Except with the fixation with 3 pins where an initial bending could be observed, failure is not a plastic deformation of the internal fixation device.

Bone Nails↗

PubMed1995

[Healing of spiral fractures in the sheep tibia comparing different methods--osteosynthesis with internal fixation, interlocking nailing and dynamic compression plate].

The healing process of spiral fractures of the sheep tibia was investigated in an experiment with simulated clinical conditions. The effects of conventional internal fixation techniques with the DCP and the intramedullary nail are compared with those of internal fixation with the spine fixator. The internal fixation techniques are described in terms of their bending stiffness when mounted on the fractured bone. The in vivo investigation was documented clinically and radiographically and the post mortem specimens were evaluated histologically. The bending stiffness of the healed bone was assessed in relation to the contralateral side. After application of the DCP, primary healing took place and extensive transcortical necrosis occurred in the implant bed. Intramedullary nailing led to secondary healing and to necrosis of the inner cortex close to the endosteum. After internal fixation with the spine fixator, gap healing took place and no cortical necrosis was observed. The clinical course was generally good after all procedures. The histological evaluation shows that damage to the vascularity of the bone can only be avoided by using the spine fixator. This principle seems to be appropriate for the purposes of biological internal fixation.

Animals↗

PubMed1984

The effect of internal fixation without arthrodesis on human facet joint cartilage.

Internal fixation of the spine combined with limited or no fusion has been advocated in the treatment of thoracolumbar fractures, spondylolisthesis, and severe juvenile spinal deformities. Internal fixation without arthrodesis of canine facet joints has been shown to result in the irreversible gross and histologic findings typical of osteoarthritis. Surgery was performed in eight patients for the treatment of thoracolumbar fractures. In each patient, Harrington distraction instrumentation was placed across at least two vertebral segments above and below the fused area. Instrumentation was removed six to 26 months following the initial surgery. A unilateral partial facetectomy was performed at the facet joint above the lower Harrington hook. Gross examination of the facet joints revealed areas of fibrillation, fissures, and thinning of the normal cartilaginous surface characteristic of osteoarthritis. Histologic examination revealed consistent areas of erosion of the vascular tidemark, osteophyte formation, subchondral remodeling, fibrillation, and loss of the normal cartilage cellularity. These findings were consistent with the histologic appearance of osteoarthritis. Internal fixation of the spine without arthrodesis is not an innocuous procedure and may be a predisposing factor in the development of symptomatic spinal arthritis.

Adolescent↗

PubMed1993

Evaluation of rigid internal fixation of mandible fractures performed in the teaching laboratory.

Rigid internal fixation of mandible fractures is advocated as an effective means of providing undisturbed healing and immediate function. However, its application in the clinical setting has resulted in many technique-related failures. To determine the reasons for clinical failure and to help develop improved means of providing successful fixation, the results of plate application in the teaching laboratory were evaluated. Seventy-four surgeons taking the AO/Association for the Study of Internal Fixation (AO/ASIF) maxillofacial course in Davos, Switzerland and 56 surgeons taking the advanced AO/ASIF course in Naples, FL applied rigid internal fixation devices to a mandibular fracture model. Treatment was evaluated for anatomic morbidity and effectiveness. In Davos, 92 of 121 subcondylar, body, symphysis, and ramus fractures (76%) were treated effectively. This included 22 of 34 symphysis fractures (65%). In Naples, 11 of 28 symphyseal fractures (39%) were fixed effectively with lag screws without anatomic morbidity. Technique failure is a frequent event in the application of rigid internal fixation devices to mandible fractures. Lag screw fixation of symphyseal fractures had a particularly high rate of technique-related failure.

Bone Plates↗

PubMed1989

Reconstruction of the lumbar spine using AO DCP plate internal fixation.

Augmentation of lumbar spine fusion with internal fixation using pedicle screw systems has gained wide currency because it offers rigid stabilization to foster fusion healing. The AO DCP plate has been employed in Europe as a spinal implant with pedicle fixation using 6.5 mm, full-threaded cancellous bone screws with success. This report details the experience of using this device for lumbar spine fusion in a series of 46 North American patients with a mean follow-up of 1.25 years (range 1-2.5 years). Thirty-one patients had had prior lumbar spine surgery with poor outcomes, and 15 had had no prior surgery. All were treated surgically for lumbar degenerative disease with canal decompression, internal fixation with AO plates, and fusion with autologous bone grafting posterolaterally. Complications included two early and one delayed wound infection; five cases of screw loosening; three cases of screw breakage; and three cases of screw impingement upon a nerve. Results of surgery in 17 patients with failed interbody fusion included good to excellent pain relief in 59%, and solid fusion in 76%. In 14 patients with failed posterior surgery the good to excellent pain relief rate was 79%, and the fusion rate was 86%. In 15 patients undergoing primary surgery there was 89% good to excellent pain relief and a solid fusion rate of 87%. The benefits accruing from augmentation of the fusion with internal fixation using AO DCP plates are positive and justify its continued use. Complications encountered in the early experience have been significantly reduced in subsequent series, indicating the existence of a "learning curve" effect which would mandate specific training of spinal surgeons in the technique.

Bone Plates↗