Additive Manufacturing Fixture Box for Bone Measurement

Bone is unsymmetrical, porous and complex structure as well. Therefore, it is very challenging to measure its dimensions by both contact and noncontact methods using Co-ordinate Measuring Machine (CMM). Especially, in recent years, bone measurement data is highly needed for various medical applications (anatomical study, fabrication of implant, surgery, etc.). Total Knee Replacement (TKR) is nowadays becoming popular in bringing back of injured person to normal life. TKR needs exact three-dimensional (3D) data for making functionally-satisfactory implant which in turn almost eradicating post-surgical management. In order to acquire 3D bone data it obviously needs an aiding device (precise holding and rotating device for bone measurement). In this, a site-specific rotating box with gears was indigenously designed, developed and manufactured using Poly Lactic Acid (PLA) as material through 3D printing. The additively-manufactured fixture box was used to hold and rotate (0.2o resolution) the bone precisely to obtain the three dimensional data and further imported it to Computer Aided Design (CAD) system for generating 3D model of knee joint. For verification and validation purpose; measurement done by fixture box aided CMM was compared with results measured by Vernier calliper. It showed reasonably close in agreement which pave the way in furthering this research.