Clubfoot is one of the most common pathologies of the foot affecting 1 in 1000 newborn babies according to statistics. The first treatment approach is by using conventional procedures, such as plaster and cast, and, the literature reports a range of failures causing relapse. Patients with severe or relapsed cases or patients that are treated later in life may require unconventional procedures to provide correction. In order to increase the success rate after the correction, it is necessary to: a)perform analyses to improve the current treatments and b) investigate the tissues involved in this pathology in order to have a better understanding of clubfoot to develop future treatments. The Ilizarov fixator has been shown to be a good alternative for complex and relapsed cases. However, there are no numerical nor experimental studies to: a) improve the efficiency of the frame deployment for clubfoot, b) provide guidance on the right adjustment procedures, and c) understand the mechanical behaviour of the frame applied to clubfoot. This makes the adjustments fully dependent on the surgeon's experience instead of systematic guidelines/procedures. This results in configurations that induce stresses in the fixator that are transferred to the tissues and leading to a reduction in the success rate. Furthermore, the literature on the correction of clubfoot in babies and the role of the tissues in babies' feet during the correction is limited.Therefore, the aim of the thesis is to analyse the relationship between the adjustments of the connectors and the displacements of the fixator rods, on the one hand, and the stress-strain induced in the rods and fixator, on the other hand. This is achieved by means of a finite element analysis of the stress-strain distributions in the fixator components. The predicted stresses are used for the identification of the components that should be adjusted in the fixator to prevent them from failure. The findings and results in the thesis will enable surgeons to understand better the mechanical behaviour of the Ilizarov frame in clubfoot, and they will facilitate the establishment of a functional range of the fixator in order to improve the current procedures. Another aim is to investigate the mechanical behaviour of one of the most affected bones during the correction of clubfoot in babies, namely the talus. The literature reports a change of shape in the talus during clubfoot correction using conventional procedures. This can result in a change of the stress distribution in the foot tissues during gait in latter stages of life leading to different pathologies. This clearly shows the importance of investigating the mechanical behaviour of the talus. This is the first numerical study to investigate the right adjustment procedures of the frame for clubfoot. It is expected that the findings of this research contribute to the improvement of the current corrective procedures based on the use of the Ilizarov frame and to improve the understanding of clubfoot in babies.
|Date of Award||1 Aug 2016|
- The University of Manchester
|Supervisor||Sunday Oyadiji (Supervisor)|
- Ilizarov, frame, talus, babies, fixator. FE analisys