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At least 145 records · Page 8Linked to original sources
PubMed2002

Treatment of distal femoral nonunions by external fixation with simultaneous length and alignment correction.

The use of external fixation for management of distal femoral nonunions may minimise some of the problems frequently encountered in these patients. Fifteen patients treated by external fixation for distal femoral nonunions between 1987 and 1997 were reviewed. There were nine males and six females. The average age was 35.4 years (17-53) with an average follow up of 4.6 years (2-8). Nine followed an open fracture, five a closed fracture and one a femoral osteotomy. Five of the cases were infected nonunions. In all cases an internal fixation device was used as the initial method of treatment. All patients had the nonunion site stabilised with an external fixator. In 12 cases the knee joint was crossed with the fixator to further stabilise the fracture site. All patients had some degree of leg length discrepancy or malalignment that required correction. Fourteen cases united. The other patient united following intramedullary nailing. The average time to union was 10.4 months (4-24). The average range of movement was 80 degrees after treatment. Up to 9 cm of lengthening was achieved using the external fixation system (mean 5.0 cm). The mean angular correction was 15 degrees. One patient had persistent pain despite union at the time of the last follow up. The advantages of preservation of soft tissue, immobilisation of the fracture site by crossing the knee joint and the facility for proximal lengthening make external fixation a definite option in the management of distal femoral nonunions.

Adolescent↗
PubMed1998

Arthroscopic debridement of external fixator pin tracts.

Major external fixator pin tract infection can be managed by curettage, overdrilling or excision of the pin tract. An alternative is arthroscopic debridement which allows thorough curettage with the advantage of direct inspection of the pin tract to ensure clearance of all necrotic tissue from the tract base and walls. To date, arthroscopic pin tract debridement has been used successfully to manage 25 pin tracts in six patients. Adequate visualization of the pin tract throughout its course was possible in all cases. Two patients subsequently underwent intramedullary nailing without complication. No recurrent infection has occurred at review at 13 months.

Arthroscopy↗
PubMed2001

Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.

BACKGROUND: Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation. METHODS: Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. RESULTS: Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04). CONCLUSION: These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.

Animals↗
PubMed1990

Design and testing of external fixator bone screws.

In external fixation, bone screw loosening still presents a major clinical problem. For this study, the design factors influencing the mechanics of the bone-screw interface were analysed and various experimental screws designed with the intention of maximizing the strength and stiffness of the inserted screw. Push-in, pull-out and bending tests were then carried out on the three experimental screws, and on two commercially available screws in both a synthetic material and in cadaveric bone; photoelastic tests on different screw threadforms were also performed. The results of the push-in and pull-out tests indicate that both the screw threadform and cutting head have a significant effect on the holding strength of the screw. The photoelastic tests show that most of the applied load is distributed over the first few threads closest to the load, and that the area between the thread crests is subjected to high shear stresses.

Biomechanical Phenomena↗
PubMedDate not supplied

Comparison of crossed pins and external fixation for correction of angular deformities about the knee in children.

External fixation was compared to crossed Steinman pins and plaster for fixation after osteotomy about the knee in children. A group of 26 patients treated by external fixation was compared to a control group of 26 patients fixed with crossed Steinman pins and casting. The groups were matched for age, height, and weight. Overall there was a 100% union rate. Preoperative deformity and postoperative correction were similar in the two groups. The time to union was significantly longer, and there were significantly more complications in the external fixator group. There were 16 complications (62%) in the external fixator group and five (19%) in the control group. Complications included pin tract infections, peroneal nerve palsy, and delayed union. External fixation provides certain advantages for fixation after osteotomies about the knee in children but is associated with a variety of complications.

Adolescent↗
PubMed2001

In vitro comparison between a DCP and external fixator for pancarpal arthrodesis in the dog.

Many clinical reports have previously documented the advantages of plates or external fixations but surgeons prefer to use plate for better acceptance by the owner, less dressing and a decreased rate of infection. In order to address complications of carpal surgery, infections, arthritis and osteomyelitis, external fixation is warranted. Twelve canine forelimbs, free of abnormality, were tested under compression to evaluate the in vitro biomechanical behaviour of the normal carpus. This behaviour was compared with that of a stabilized carpus stabilised by panarthrodesis with either plates (8 hole 3.5 mm dynamic compression plate (DCP), or a type II external fixator. Deformation vs. load was recorded after compression with a testing machine in conjunction with a digital data acquisition system. Yield load, maximal load to failure and stiffness were then calculated. Variables were significantly greater for arthrodesis with external fixation and plates than for intact forelimbs. The stiffness and the MLF after stabilisation with plates or external fixators did not differ significantly. At MLF, fracture of the third metacarpus appeared with plates, whereas deformations of the pins and bars of the external fixators increased with load. Stabilisation with plate or external fixation allowed more load to failure than the intact carpus. The biomechanical behaviour of both methods of arthrodesis was identical during loading. However, after rupture, external fixation was more plastic. External fixation, which is less often used than plates for pancarpal arthrodesis, mainly due to the occurrence of sepsis, may be useful for arthrodesis of the carpus in big or active dogs.

Animals↗
PubMed1992

[Stabilizing the pelvic ring with the external fixator. Biomechanical studies and clinical experiences].

Experimental studies were performed on anatomic pelvis specimens. In different series of experiments the positioning of the screws and the assembly of the external fixator were changed. We tried fixing the external fixator to the screws at varying distances from the body surface. For stabilisation of the fractured pelvic girdle a self-constructed "bow fixator", fixed to supra-acetabular screws with proximal compression and distal traction showed the best results. Homogeneous distribution of the pressure could be achieved on the unstable dorsal pelvic ring structures. In clinical routine we used the triangular external fixator, which in the experimental situation yielded results close to those of the bow fixator. External fixation of the pelvic girdle has been performed 128 times since 1977, in January 1991 a prospective study was started. For Tile type B injuries the external fixator itself represents an effective, minimally invasive system, but type C fractures often require an additional internal fixation of the dorsal lesion.

Acetabulum↗
PubMed1999

Supplemental pinning improves the stability of external fixation in distal radius fractures during simulated finger and forearm motion.

External fixation is commonly used in the treatment of distal radius fractures. In this in vitro study, we investigated changes in fracture stability when using supplemental radial styloid pinning in combination with external fixation. Eight previously frozen cadaveric upper extremities were mounted in a computer-controlled wrist-loading apparatus. This device was used to generate finger and forearm motions through loading relevant tendons. An unstable extra-articular distal radius fracture was simulated by removing a dorsal wedge from the distal radius metaphysis. An electromagnetic tracking system measured fragment motion following randomized application of a Hoffman external fixator, a Hoffman external fixator with 2 supplemental radial styloid pins, and a dorsal 3.5-mm AO plate. Regardless of the fixation technique used in this unstable fracture model, fragment motion occurred when postoperative finger and forearm motions were simulated. The addition of radial styloid pins to a construct stabilized by an external fixator significantly improved fragment stability, approaching that achieved with the dorsal AO plate.

Biomechanical Phenomena↗
PubMed1987

External fixation of the upper extremity.

External fixation of forearm and arm fractures is an excellent treatment option, particularly in compound, comminuted fractures that result from high-energy trauma. Limb salvage and good function have been achieved in 75% of cases by applying the principles outlined. Problems with delayed bone union have been recognized and emphasize the importance of supplemental bone grafting. A number of external fixation systems are applicable to these upper limb fractures, and the authors have not found one system superior to the others. Open pin insertion is preferred, and pins (three proximal and three distal) are ideally placed near the fracture site for optimal stability.

Arm Injuries↗
PubMed1992

A report of the first 20 cases using a simple external fixator.

The results of treatment using a locally-designed external fixator in 20 patients are presented. Open fractures were the main indications for external fixation. Pin tract infection occurred in 8 patients. Only 2 patients had unstable fixation which required removal of the device. One third of patients developed malunion exceeding 15 degrees and two thirds had joint stiffness after conversion to plaster cast. This external fixator is adequate in the treatment of most open fractures of the tibia. However, improved techniques of pin insertion and cast application upon removal of the external fixator may help to reduce the incidence of pin tract infections and malunion.

Adolescent↗
PubMed1989

The effect of rigidity on fracture healing in external fixation.

Knowledge of the basic biomechanics of external fixation is necessary to obtain the full benefits of the technique for bone fracture treatment. The rigidity of external fixation, including pin-bone interface stresses, is discussed and bone healing and remodeling under different fixation stiffnesses and fracture gap conditions are described. The rigidity of fixation ultimately depends on the biomechanical characteristics of the fracture, the accuracy of reduction, and the amount of physiologic loading. Comparative experiments using a canine tibial fracture model have suggested that fixation rigidity is important in early bone healing and in the prevention of pin loosening. Bone union can be achieved under external fixation through different pathways, ranging from callus-free gap healing under a rigid neutralization configuration to direct-contact healing with periosteal new bone formation under axially dynamized stable fixation. Cortical reconstruction by secondary osteons seems to be important for the ultimate strength of the bone union.

Animals↗
PubMed2002

The treatment of open tibial fractures and of tibial non-union with a novel external fixator.

We report the results of external fixation in 29 patients treated for tibial fractures and tibial non-union using a novel multi axial external fixator (MAXX) followed prospectively until bony union. The results of treatment were classified according to the Association for the Study and Application of the Method of Ilizarov (ASAMI). Overall, 13 patients had excellent bone results; 13 had good bone results; two had fair bone results, and 1 patient had poor bone results. Regarding functional results, 21 patients had excellent results; 6 obtained good results; none had fair results, and two had poor results. Acute patients did better functionally than chronic patients. This fixator is safe and versatile, although the indications for its use are very specific.

Adolescent↗
PubMed1999

Experimental external fixation combined with percutaneous discectomy in the management of scoliosis.

STUDY DESIGN: An assessment of the value of external fixation with or without percutaneous discectomy for the management of scoliosis in young rabbits with induced progressive thoracic scoliosis. OBJECTIVES: To investigate in an experimental setting the effect of external fixation with or without percutaneous discectomy for the management of scoliosis, as a preliminary study to precede clinical consideration. SUMMARY OF BACKGROUND DATA: External fixation of the spine using percutaneous transpedicular screws has been used clinically for cases of traumatic spinal injury, infectious spine, or chronic low back pain caused by a disc lesion. Percutaneous discectomy for the management of scoliosis has been reported. METHODS: Thirty-two young rabbits underwent partial resection of the right lower ribs. Nine rabbits were not treated after production of scoliosis and were followed as controls. At 4-6 weeks after production of scoliosis, in 23 animals, Kirschner wires were inserted percutaneously into the T9-T10 and L1-L2 disc space, and both ends were attached to an external fixator after correction of the scoliosis. In 8 of those 23 animals, percutaneous discectomy was also performed at the apex of the caudal compensatory curvature. RESULTS: In these 23 animals, the initial correction by fixation on of the caudal vertebrae was accompanied by a derotation in the apex. Five animals treated with external fixation only and four treated with combined percutaneous discectomy survived with external fixation until the age of 17 weeks and were followed to the natural cessation of the curve progression, at which the fixation was removed and a final assessment was made. The mean progression of curvature was 15.8 degrees in the group of five animals with external fixation only, and 33.8 degrees in the controls. In the group of four animals treated with supplementary percutaneous discectomy, however, the treated disc space became rigid, and the mean progression of curvature after removal of the fixation was only 5.3 degrees. CONCLUSIONS: The results of the current study suggest the potential for external fixation to allow for derotation and, when combined with percutaneous discectomy, to offer a feasible method of managing scoliosis in the human adolescent. This study was a preliminary experimental study; further experimental studies are planned to develop this novel technique.

Animals↗
PubMed1993

External fixation in comminuted upper femoral fractures.

External fixation of comminuted upper femoral fractures has not been studied widely. The minority of such fractures which cannot be fixed internally due to clinical and anatomical problems are generally treated in traction. Early external fixators were not sufficiently robust to hold these fractures and pin site problems are more common in femoral fixation than in the tibia. A study was undertaken including all patients with comminuted upper femoral fractures who were too unwell or otherwise unsuitable for internal fixation. The long-term results were comparable, if not superior to traction, and patient comfort and mobilization were much improved.

External Fixators↗
PubMedDate not supplied

Psychosocial issues relating to external fixation of fractures.

The use of external fixation devices has become increasingly popular for the treatment of fractures and for limb reconstruction procedures. This article reviews the nursing literature that examines psychosocial issues in the context of treatment with external fixation. Nearly all the evidence cited is anecdotal. Personal experience should not be ignored, but this review exercise highlights the lack of research-based evidence to back up provision of care in what is a fundamentally important aspect of the patient experience.

Adaptation, Psychological↗
PubMed1995

External fixation of open femoral shaft fractures.

OBJECTIVE: To determine whether external fixation proves to be a sensible technique for definitive stabilization in open femoral fractures. DESIGN: Retrospective clinical study. MATERIALS AND METHODS: From 1985 to 1989, 18 patients (mean ISS 25.4) with open femoral fractures (type II 11%, type III 89%) were treated by primary and definitive external fixation. After failure of closed reduction procedures, open reduction via debrided soft tissue wounds was employed in 72%. Supplemental internal fixation of large wedge fragments was required in 66%. External fixators were removed after a mean of 166 days. Early deep infections developed in 11%. Additional cast, brace, or traction were not required. MEASUREMENTS AND MAIN RESULTS: After a mean follow-up period of 58 months, 88% of the surviving 17 patients were clinically and radiologically evaluated and 12% were interviewed by telephone. Eleven percent developed late deep infection of the femur concerned. Eighty percent have had full or slightly restricted knee motion. The mean knee flexion amounted to 130 degrees. Relevant shortening of the femur was diagnosed in 7%. Nonunions or relevant malunions were not observed in our series. CONCLUSIONS: These morphologic and functional results compare with those published for alternative stabilization techniques of femoral fractures. For special indications, external fixation is considered to be a sensible technique for primary and definitive treatment of open femoral fractures.

Adolescent↗
PubMed2000

The anatomical base of unilateral external fixation in the upper limb.

Unilateral external fixation requires an anatomically sound implantation of screws into the upper extremity. Detailed knowledge about the anatomical situation in the areas of pin implantation is of great importance. This paper focuses on relevant anatomical landmarks when implanting screws for external fixation in the humerus, the elbow, the forearm and the hand by studying anatomical specimen.

Arm↗
PubMed1994

Comparison of the Howmedica and Synthes military external fixation frames.

To direct the U.S. military purchase of deployable external fixation gear, a project was designed to compare the biomechanical properties and ease of clinical application of military external fixators developed by Synthes and Howmedica. The project assessed (a) ease of application, (b) biomechanics, (c) heat stability, and (d) product line compatibility. Pretrained general surgery residents were provided with fresh cadaver limbs with simulated grade IIIB tibial fractures and 5-cm middiaphyseal defects. All chose the Howmedica Ultra-X for its ease of application but, on manual testing, noted that the Synthes Trauma-Fix was more stable. The frames were biomechanically tested in a previously validated model with strictly controlled parameters. The Howmedica Ultra-X demonstrated only 75% of the compressive stiffness, 29% of the anteroposterior bending stiffness, and 51% of the torsional stiffness of the Synthes Trauma-Fix. The Ultra-X failed to withstand steam sterilization and was significantly weaker than, and incompatible with, Howmedica's commercially available product. The Trauma-Fix demonstrated no statistically significant difference from Synthes' commercially available product. The Howmedica Ultra-X is unsuitable for military external fixation: The biomechanical properties are not equivalent to those of the unilateral Hoffmann frame, it is incompatible with commercially available Howmedica external fixators, and it fails to withstand heat sterilization.

Biomechanical Phenomena↗