BIOMECHANICAL EVALULATION OF IM NAILING VERSUS PLATING OF DISTAL METAPHYSEAL TIBIA FRACTURES

Participants: T.T. Le, E.P. Frankenburg, D.S. Scott, K. Oikarinen, B.T. Nolan, D.C. Kayner, J. Hall, E.T. Keller, M.A. Karunakar, J.A. Goulet, S.A. Goldstein

Keywords: fracture fixation, distal tibia fracture, mechanical properties

Introduction

The treatment of distal metaphyseal tibia fractures remains controversial. Proximity of the fracture to the plafond and condition of the soft tissue injury dictate the type of implant that can be used for fracture stabilization. The purpose of this study is to perform a biomechanical evaluation of IM nailing versus plating in the treatment of distal metaphyseal tibia fractures.

Materials and Methods

Eighteen human tibias will be used for the study. They will all be evaluated prior to admitting to the study by means of radiographic and DEXA scanning analysis in order to help normalize the bone quality. After dissection of all soft tissue, a short oblique fracture pattern of 30 degrees to the distal extent of the tibia and 4 cm from the plafond will be created. The fractures will then be fixed by one of three different constructs. Each construct will be implanted into six specimens. Group A will consist of fractures stabilized with an IM nail (Zimmer) with the two most distal locking screws placed perpendicular to each other. Two different implants will be used for the plating technique. Group B will consist of fractures stabilized by the distal tibia periarticular plate (Zimmer) versus Group C consisting of a standard 12 hole, 3.5 mm LCDCP (Synthes or Zimmer). Stiffness of the construct, displacement, and local motion at the fracture site will be analyzed with the construct loaded under compression, and then torsion.

Progress

The project is in its initial stages. Specimens are being obtained, as are fixation devices. Testing protocols are being developed, including methods of determining local displacements at the fracture site.