Analysis of Radial Head Implant Length with Use of Contralateral Elbow Radiographs.

Abstract

This article describes a technique in which measurements are obtained from radiographs of the contralateral, normal elbow to predict the magnitude of overlengthening resulting from use of a metallic radial head prosthesis. Obtain bilateral digital anteroposterior radiographs of the elbows that are orthogonal to the forearm in 45° of flexion and neutral forearm rotation. Draw the angle on the radiograph of the normal elbow. Draw the same lines and angle and perform the same measurements on the implant radiograph. The virtual length of the native radial head implant (<i>L-NRH</i>) is subtracted from the virtual length of the radial head implant (<i>L-RHI</i>), which results in the magnitude of the radial head implant overlengthening in millimeters: (<i>L-RHI</i>) - (<i>L-NRH</i>) = overlengthening. The radiographic measurement technique was validated in a cadaveric study. IndicationsContraindicationsPitfalls & Challenges.