gms | German Medical Science

German Congress of Orthopedic and Trauma Surgery (DKOU 2017)

24.10. - 27.10.2017, Berlin

The comparative evaluation of the primary fixation in different types of corrective osteotomy of the first metatarsal bone in cases of hallux valgus

Meeting Abstract

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  • presenting/speaker Oleg Loskutov - Medinua Clinic&Lab, Dnepr, Ukraine
  • Ksenia Furmanova - Medinua Clinic&Lab, Dnepr, Ukraine
  • Artem Naumenko - Medinua Clinic&Lab, Dnepr, Ukraine

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocPO21-985

doi: 10.3205/17dkou749, urn:nbn:de:0183-17dkou7494

Published: October 23, 2017

© 2017 Loskutov et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objectives: A task to restore normal functionality of the foot is important in orthopedics.This is primarily due to the fact that this biomechanical system provides the harmony of human movement and determines the comfort of his life.Despite the variety of methods of treatment of this disease a large number of results are still negative andin some cases, disabling.The creation of high-quality mathematical models can provide an opportunity for orthopedist from a point of demonstrative medicine to choose a rational method of treatment, and increase the success rate of corrective operations.The goal is the evaluation of the strength of the primary fixation of the first metatarsal bone.

Methods:

  • The finite element model of the first metatarsal bone of the normal foot was developed to study the stress-strain state of the bones by the impact of loads on the head of the bone and to evaluate of the proper head displacement;
  • The finite element model of the first metatarsal bone of the foot with a valgus deformity was created to assess the quality of the primary fixation after chevron osteotomy;
  • A comparison of the stability of fixation of chevron osteotomy using different types of implants;
  • The finite element model of the first metatarsal bone of the foot with a valgus deformity after osteotomy scarf with hallux valgus was developed and the quality of primary fixation was evaluated.

Results and Conclusion: Geometrical model of the considered normal first metatarsal of the foot is based on CT scans (CT). On the basis of the exact geometrical shape of normal patient's foot first metatarsal the finite element model was developed and it allows to study the influence of the load on the bone structure of the first metatarsal bone.

It has been found that a local stiffness after osteotomy surgery reduces significantly and bone strength is inadequate to take the full (preoperative) load. The research showed that the metatarsal head after chevron osteotomy is 5.1 times more mobile under the influence of the vertical load in comparison with the preoperative condition. More in-depth insertion of the screw has a positive effect on the quality of bone fragments fixation, however, the through-fixing is not advisable in this case.Fixation of bone fragments with a needle during the chevron osteotomy makes them 39 % more mobile than in the screw fixation and 11% more mobile in case of two-screw fixation. Between the K-wires and screws clamps for bone fragments after chevron osteotomy the screws should be preferred. After Scarf osteotomy with a vertical load applied the head of the metatarsal bone is 17.6 times more mobile in comparison with the preoperative condition.Chevron surgery is more preferred than the scarf one considering the quality of fixation. 6 mm bone head correction after scarf osteotomy showed that bone fragments are 2.9 times more mobile than after chevron.The Scarf osteotomy is preferred according to the convenience and reliability of bone fragments fixation in case of impossibility to perform.