Three-Dimensional Printing of Innovative Intramedullary Pin Profiles with Direct Metal Laser Sintering

In the past one decade, use of intramedullary (IM) pins (Steinmann pins or end-threaded pins) as implants for the repair of long bone fractures in canine has been widely reported. One of the major limitations of these pins is implant dislodgement and proximal migration mainly due to less retention rate in the proximal end. Some studies have reported the fabrication of IM pins for canine by conventional machining methods, but hitherto little has been reported on the innovative profiles of IM pins for canine prepared by direct metal laser sintering (DMLS) of 17-4 precipitation-hardening (PH) stainless steel (SS). This paper reports the fabrication and process parametric optimization for innovative IM pin profiles on 17-4PH SS with DMLS. The selected output parameters are surface hardness (HV), surface roughness (Ra), and dimensional error (∆d). The results of the study suggest that laser power 100 W, scan speed 1200 mm/s, and layer thickness-0.04-mm are the best settings of DMLS from a multi-factor optimization viewpoint. The results have been supported with scanning electron microscopy-based photo-micrographs, 3D rendered images, porosity (%), and grain size number.