The preclinical sheep model of high tibial osteoto

Authors: Dietrich Pape Henning Madry

Publish Date: 2012/07/21

Volume: 21, Issue: 1, Pages: 228-236

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Abstract

To develop a preclinical large animal model of high tibial osteotomy to study the effect of axial alignment on the lower extremity on specific issues of the knee joint such as in articular cartilage repair development of osteoarthritis and meniscal lesions Preoperative planning surgical procedure and postoperative care known from humans were adapted to develop a HTO model in the adult sheepThirtyfive healthy skeletally mature female Merino sheep between 2 and 4 years of age underwent a HTO of their right tibia in a medial openwedge technique inducing a normal group 1 and an excessive valgus alignment group 2 and a closedwedge technique group 3 inducing a varus alignment with the aim of elucidating the effect of limb alignment on cartilage repair in vivo Animals were followed up for 6 monthsSolid bone healing and maintenance of correction are most likely if the following surgical principles are respected 1 medial and longitudinal approach to the proximal tibia 2 biplanar osteotomy to increase initial rotatory stability regardless of the direction of correction 3 small narrow but long implant with locking screws 4 posterior plate placement to avoid slope changes 5 use of bicortical screws to account for the brittle bone of the tibial head and to avoid tibial head displacementAlthough successful high tibial osteotomy in sheep is complex the sheep may—because of its similarities with humans—serve as an elegant model to induce axial malalignment in a clinically relevant environment and osteotomy healing under challenging mechanical conditionsWe thank Dr vet Altmann and her team Bad Langensalza for her ongoing support in the treatment and care of the animals supported by an AGA Research Grant Forschungsförderungsantrag 29/2008 and by the Department of Orthopaedic Surgery Saarland University Head Prof Dr med Dieter Kohn Henning Madry and Dietrich Pape are partners in the Cartilage Net of the Universität der Großregion/Université de la Grande Région UGR supported by the INTERREG IV Programme of the European Union

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