The in vivo study of injection moulded 316L stainless steel fracture fixation plate

Abstract

Metal Injection Moulding (MIM) is a revolutionary new class of medical implant fabrication in orthopaedics. This technology employs natural resources and holds great promises in producing large quantities of metallic parts for prosthetic implant at minimum outlay without compromising its quality. The present study was conducted to compare potential effects of MIM plate for internal fixation in fracture healing in New Zealand White (NZW) rabbits with conventional machining plate (Synthes®) as control. Following research approval by IIUM Ethics Committee (IIUM/305/20/4/10), forty rabbits were used and randomly divided into two groups. All rabbits underwent single transverse mid-shaft tibial fracture surgery and fixation under anaesthesia. The fractures were fixated with either the MIM plate or conventional plate (Synthes®). The monitoring of fracture healing was carried out at week 3, 6, 9, 12 and 26 according to ISO10993-2:2006 & ISO10993-6:2009 standards. The status of bony union was examined by means of plain radiographic assessment, macroscopic observation and, histological evaluation. There were callus formations in both groups. Bony union was evident at week 6 post-operatively, whilst bone remodelling was completed at week 26 as indicated by plain radiograph assessment and macroscopic evaluation. Histological assessment showed that both groups possessed mild to moderate callus bridging at week 3 and week 6, respectively. Complete remodelling of cortical bone was evidenced at week 26. The plate was neither broken nor bent during the study. These findings indicate that the MIM plate has equal potential to hold the fracture as the conventional plate. Therefore, the locally manufactured MIM plate has the potential to be used as an alternative internal fixator for fracture management in orthopaedic considering the value and conservation of natural resources.