Wire tension versus wire frequency: An experimental Ilizarov frame study

2010 ◽  
Vol 43 (12) ◽  
pp. 2327-2331 ◽  
Author(s):  
Valentina La Russa ◽  
Bjørn Skallerud ◽  
Jomar Klaksvik ◽  
Olav A. Foss
Keyword(s):  
Author(s):  
P J Hillard ◽  
A J Harrison ◽  
R M Atkins

The Ilizarov frame uses tensioned fine wires to support bone fragments. The objective of this study was to determine whether these wires deformed plastically under functional load bearing and to determine the significance of such deformation on the long-term performance of frames used for treating lower limb conditions. The mechanical characteristics of the wires were determined by means of destructive tensile tests and used in the construction of a series of finite element models replicating typical frame configurations. Each model was then subjected to a single load cycle representing a single step and the residual displacement (i.e. plastic deformation) was determined. In each case a residual displacement of between 0.26 and 0.42 mm was observed giving a corresponding reduction in wire tension of between 8.3 and 32.8 per cent. These reductions in wire tension reduce the frame's overall stiffness and so compromise its ability to inhibit high-amplitude axial and shear motions at the fracture site which are deleterious to the healing outcome.


2011 ◽  
Vol 44 (8) ◽  
pp. 1454-1458 ◽  
Author(s):  
Valentina La Russa ◽  
Bjørn Skallerud ◽  
Jomar Klaksvik ◽  
Olav A. Foss

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Julian Fürmetz ◽  
Chris Soo ◽  
Wolf Behrendt ◽  
Peter H. Thaller ◽  
Holger Siekmann ◽  
...  

A common treatment of tibial defects especially after infections is bone transport via external fixation. We compare complications and outcomes of 25 patients treated with a typical Ilizarov frame or a hybrid system for bone reconstruction of the tibia. Average follow up was 5.1 years. Particular interest was paid to the following criteria: injury type, comorbidities, development of osteitis and outcome of the different therapies. The reason for segmental resection was a second or third grade open tibia fractures in 24 cases and in one case an infection after plate osteosynthesis. Average age of the patients was 41 years (range 19 to 65 years) and average defect size 6.6 cm (range 3.0 to 13.4 cm). After a mean time of 113 days 23 tibial defects were reconstructed, so we calculated an average healing index of 44.2 days/cm. Two patients with major comorbidities needed a below knee amputation. The presence of osteitis led to a more complicated course of therapy. In the follow up patients with an Ilizarov frame had better results than patients with hybrid systems. Bone transport using external fixation is suitable for larger defect reconstruction. With significant comorbidities, however, a primary amputation or other methods must be considered.


2008 ◽  
Vol 36 (4) ◽  
pp. 1284-1285 ◽  
Author(s):  
J. Zier ◽  
M.R. Gomez ◽  
D.M. French ◽  
R.M. Gilgenbach ◽  
Y.Y. Lau ◽  
...  
Keyword(s):  

Author(s):  
R A Wilkes ◽  
A Harrison ◽  
R M Atkins

A novel fine wire bone transport system for use with Ilizarov frames has been used in Bristol. It uses parallel wires instead of crossed wires. Its stiffness has been tested and compared with a crossed wire construct. In its basic form it is not as stiff to bending and shear loading, however, by modification it can be made at least as stiff. A parallel wire construct does not transfix as much soft tissue as a crossed wire construct when used in the leg. This is advantageous, because soft tissue transfixion causes pain and limb swelling, which impair patient mobilization.


2021 ◽  
Vol 12 (7) ◽  
pp. 88-93
Author(s):  
Anoop Raj Singh ◽  
Javed Ahmad ◽  
Vivek Kumar Shrivastava ◽  
Pavneesh Kumar

Background: Principle of distraction and an indirect reduction was used to promote healing of fractures and adequate regeneration of cartilage at the subtalar joint. Aims and Objectives: The study was aimed to elaborate and develop role of Ilizarov as an alternative biologicalmethod to manage intraarticular fracture calcaneum with minimal chances of infection. Materials and Methods: Twenty-one patients were studied and the mean age of patients was 40.7 years (span: 20 to 65 years). Sanders CT classification was used to divide into type II, 11 (52.38%); type III, 7 (33.33%) and type IV, 3 (14.28%). The average followup was 17.2 months (range: 6 to 24 months). AOFAS scale for ankle and hindfoot was used for assessment of patients- 7 (33.33%) excellent, 7 (33.33%) good, 3 (14.28%) fair, and 4 (19.04%) poor results. The average score was 81.5 ±12.1. The mean period of treatment was 12 weeks (10 to 14 weeks). Results: On radiological assessment, Bohler’s angle change was 19.7±4.4 degrees to 33.51± 5.7 degrees; angle of Gissane changed from 126.4 ± 6.7 degrees preoperatively to 124.9 ± 6.9 degrees postoperatively; calcanealheight changed 40.14 ± 1.98 mm preoperatively to 43.33 ± 1.87 mm and width changed 45.09 ±3.65 mm preoperatively to 43.09 ±3.16 mm postoperatively and reduction malalignment >10 degrees in 5 patients. Superficial skin infection at wire insertion sites was the most common complication encountered in our cases. Conclusion: Our results with this ergonomic technique in a small number of 21 non-randomised cases with a mean followup of 17.2 years attribute towards an alternate surgical substitute to conventional open reduction techniques in the treatment of intra-articular fractures of calcaneum having lesser rate of complications.


2019 ◽  
Vol 13 (2) ◽  
pp. 111-120
Author(s):  
Agus Sasmito ◽  
Yudi Irawadi

The safety of the tower is depend the tension of guy wire, where it must have the same tensile stress at all positions. To meet this requirement, the load cell guy wire is designed based on strain gauge. Load cell guy wire  is designed portable and it can detect stress of the guy wire indirectly. The main component of load cell is a beam, two hooks and a cylinder to form a bending moment force in the beam, the value of the bending moment on the beam will be directly proportional to the increase or decrease in force drag on guy wire. Design process of load cell doone using mathematical analysis, and then the load cell is calibrated by standard load cell, based on the data result of calibration is known that the stress at the guy wire load cell is close and under the yield stress of the load cell material, it is proved that load guy wire cell’s design result is safe to use.


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