News |  Sitemap |  Contact
PDF Export  | 

In vivo Gait analysis in murine femoral fracture model using ImageJ and the plugin MtrackJ

Abstract:

Introduction

Gait analysis is used as a powerful technique for evaluating locomotion such as motion and load patterns in humans and large laboratory animals. In small animal models the gait analysis is only limited useful. A murine fracture model has not been described yet. Therefore the aim of the study was to define, describe and measure parameters of gait analysis in murine fracture model by the help of ImageJ, a public domain Java image processing program.

Material and Methods

Ten mice were divided into two groups. All mice underwent prior training to become accustomed to walking in the running wheel. In 5 mice, a standardized closed midshaft fracture was produced using a 3-point bending device. For fracture stabilization a common pin (10 mm) was used. 5 mice served as control group, one femoral pin (10 mm) was inserted without producing a fracture as femoral marker. Both groups were additionally marked by one tibial pin (5 mm). An x-ray permeable running wheel was used for gait analysis. Multiple running cycles were digitized with 30 images/ s by a digital angiography x-ray system to identify the markers. Fourteen days after surgery the following gait parameters were determined: the minimum and maximum tibio-femoral angle, the stride frequency, the stride time, the stride length and the stride velocity. Eighteen representative strides per mouse were analyzed. All measurements were done using the Java based open source program ImageJ. Additionally, MtrackJ (programmed by Erik Meijering) , an ImageJ plugin to facilitate manual tracking of moving objects in image sequences and the measurement of traveled distances and velocities has been used to visualize the movement of the proximal and distal femoral pin.

Results

The control group showed a significantly higher maximum (96.6 ± 1.2° vs. 74.7 ± 1.2°; p≤ 0.05) and minimum (41.6 ± 1.4° vs. 51.4 ± 1.2°; p≤ 0.05) tibio-femoral angle compared to the fracture group. Measuring the stride frequency and stride time both groups showed comparable results without significant differences (stride frequency: 4.8 ± 0.3 vs. 4.6 ± 0.3 strides/ s; stride time: 0.3 ± 0.1 s). In the control group stride length was significantly larger (9.2 ± 0.2 cm) than in the fracture group (5 ± 0.1 cm). By consequence, a significantly higher stride velocity was observed in the control group (42.7 ± 5.3 cm/ s vs. 23.6 ± 0.4 cm/ s).

Conclusion

In the present study we describe a novel approach to quantify the fixation techniques and the fracture healing process using gait analysis. This study was conducted to measure different characteristic parameters to investigate the stability served by different methods of fracture stabilization by the help of computerized image analysis via the public domain Java image processing program ImageJ and the plugin MTackJ.

The presented results will help to design future studies with standardized mechanical conditions for analyzing mechanisms of fracture healing.

Keywords:
gait analysis, mouse, femur fracture, ImageJ

Author
Alexander Kristen

Organisation   
Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Homburg/Saar, Germany

Homepage   
http://www.uniklinik-saarland.de

Short Biography   

A. Kristen, MD

*07.09.1975

Assistant Doctor since 12/2003 in the Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Homburg/Saar, Germany (Chief: Prof. Dr. med. Pohlemann)

Field of Research: Computerassisted Surgery, Integration of technology in medicine, Developement of further techniques to analyze fracture reduction processes

Recent publications:

Kristen A

[Die Umsetzung der neuen Weiterbildung zum Facharzt in der Praxis-Beispiele aus dem Klinikalltag]

MedReview. 2007

Kristen A, Culemann U, Fremd R, Pohlemann T.

[Visualization of reduction : New view of a dynamic procedure.]

Unfallchirurg. 2008

Kristen A, Culemann U, Holanda M, Pizanis A, Pohlemann T.

[Epiphysiolysis of the dens axis in the small child.]

Unfallchirurg. 2008

© Luxembourg Institute of Science and Technology | Legal Notice