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Materials Science in Additive Manufacturing MAM for orthopedic bone plates: An overview

The revelation of the role of inter-fragmentary motion medical industry, MAM has become crucial for producing
in fracture healing ushered in a new design paradigm. medical implants, particularly those aimed at repairing
Bone plates with elliptical screw holes, allowing slight axial or replacing diseased or damaged components of the
movement, were crafted to encourage secondary healing bone musculoskeletal system [30-32] . MAM facilitates the
and minimize fibrous tissue formation [14,23] . Locking plates, realization of innovative bone plate designs, employing
with their design promoting a gap between bone and plate, advanced design strategies such as topology optimization,
further advanced this cause, preserving blood supply, and lattice design, and generative design [33-35] . This approach
ensuring secondary healing . not only enhances processing accuracy and efficiency
[24]
However, a significant challenge – stress shielding but also effectively addresses critical issues like stress
– persisted. The stiffness of traditional bone plates far shielding. Moreover, advancements in MAM technology
exceeded that of natural bone, inhibiting the transfer have significantly expanded the range of bone plate
of biomechanical stimuli and potentially leading to designs, catering to highly specialized medical procedures,
bone resorption near the fracture . Addressing stress including mandibular reconstructions and patient-specific
[25]
shielding has been at the forefront of contemporary osteotomies [36-38] .
bone plate development. Strategies span novel materials, In summary, the evolution of bone plate development
refined structural designs, and cutting-edge fabrication can be delineated into three significant phases, as
techniques [26,27] . With the challenges of secondary surgeries illustrated in Figure 2. The introduction of locked
and long-term fatigue in mind, ongoing research is compression plates marked a transformative phase,
zeroing in on materials and designs that biodegrade post- transitioning from primary to secondary healing.
healing [7,28] . This change resulted in expedited healing processes
Additive manufacturing (AM) is an advanced and diminished post-healing defects. At present, the
manufacturing technology that creates parts from three- emphasis is on identifying materials that align more aptly
dimensional (3D) model data by layering materials, a with clinical requirements, paired with the adoption
process outlined by ISO/ASTM standards 52900:2021 . of advanced manufacturing techniques to produce
[29]
Metal AM (MAM) extends this principle, using metal customized, intricate bone plates. This review delves not
powder or wire as feedstock, to fabricate parts with complex only into the contemporary advancements in bone plate
geometries that are often challenging for conventional development using AM across all stages but also highlights
subtractive and formative manufacturing methods. In the potential challenges that may emerge. The content is

Figure 2. Evolution and diversity of bone plate designs. Adapted from Al-Tamimi et al., Vijayavenkataraman et al., Kanagalingam et al., Dobbe et al., and
Teo et al. [33-37] .

Volume 2 Issue 4 (2023) 3 https://doi.org/10.36922/msam.2113