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International Journal of Bioprinting 3DP Ta buttress in DDH shelf acetabuloplasty

The concept of acetabuloplasty was initially proposed in 3D printing, individualized preoperative design and
and refined by pioneers such as Konig, Spitzy, and Wiberg life-size printing enable the graft’s shape to perfectly
in the late 19th and early 20th centuries. Due to limited match the defect area, allowing for ideal placement
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understanding, early results of acetabuloplasty did not during surgery. This approach effectively avoids time-
significantly surpass those of alternative treatments. As consuming adjustments, difficulties in implantation, and
knowledge about acetabular dysplasia and acetabuloplasty unsatisfactory positioning, simplifying the surgical process,
advanced, Nishimatsu et al. continuously improved the ensuring therapeutic efficacy and safety, and reducing
surgical technique, achieving favorable outcomes in long- perioperative complications. Additionally, 3D printing
term follow-up: 87% of hips had no OA or in early OA over facilitates the creation of porous structures that promote
an average follow-up of 23.8 years. Thus, this technique bone tissue growth and allows for precise adjustment of the
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regained attention in recent years. However, previous implant’s mechanical strength to avoid stress shielding. 18,19
studies have also indicated that approximately 22% of Therefore, 3D printing is emerging as an effective method
autograft bone used in acetabuloplasty experienced bone for manufacturing implants in the field of orthopedics.
resorption, which would compromise the supporting Currently, titanium and its alloys are the most widely
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function of the acetabulum. Due to the relatively irregular used bone filler materials. Due to their structure that closely
bone morphology of the upper surface of the acetabular resembles bone tissue, high-load resistance, and excellent
rim, the mismatch between the shape of the bone graft biocompatibility, 3D-printed titanium alloy materials
and the outer edge of the acetabulum and the femoral have been widely utilized in orthopedics, particularly
head often influences the optimal placement of the bone in the functional reconstruction of severe bone defects,
graft. Consequently, the placement of the graft can easily significantly reducing the complexity and enhancing the
deviate during the procedure, particularly when placed accuracy of reconstruction. Borland et al. reported that
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too high, leading to weakened support, reduced stress the prosthesis survival rate for complex acetabular bone
distribution, and ultimately, bone resorption. Issues with defects reconstructed with titanium metal augments was
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autograft bone also include adequate coverage only in the 95.8% (23/24) over a median follow-up of 5 (range: 3–7)
lateral superior region of the acetabulum, while failing to years. However, titanium alloys lack sufficient corrosion
cover the anterior and posterior aspects. Furthermore, the resistance and osseointegration capability, often requiring
smooth and dense surface of cortical bone is not conducive surface coatings to enhance their bioactivity and corrosion
to the final attachment of the joint capsule to the bone graft resistance. 21,22 Porous tantalum metal, characterized
and the transformation into fibrocartilaginous structures. by its innovative porous structure, exhibits excellent
Therefore, in this study, the design of the buttress required biocompatibility, ideal elastic modulus, structural strength,
the curvature of the bottom surface of the buttress to corrosion resistance, and even antimicrobial properties.
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parallel the spherical surface of the femoral head. This is Many clinical and animal studies have confirmed that
aimed at restoring the concentricity of the hip joint while porous tantalum metal serves as a promising substitute
achieving an LCE angle of 30–35° and an ACE angle of for bone grafts in reconstructive surgeries. 24–26 Porous
25–30°, ensuring coverage of both the lateral and anterior tantalum has superior bio-inductive properties, promoting
aspects of the acetabulum.
cell adhesion, growth, differentiation, and the formation
The 3D printing technology represents a rapid of an abundant extracellular matrix, thereby accelerating
prototyping method that fabricates objects layer by bone ingrowth on the implant surface and early biological
layer based on digital model files. It integrates the latest fixation, which is notably superior to materials like
advancements from modern digital capture techniques, titanium alloys. Thus, tantalum metal achieves favorable
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software programming, numerical control, laser or electron reconstructive outcomes even under conditions of severe
beam technologies, and material science. Developing bone defects and poor host bone quality. Compared with
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precise and efficient surgical strategies is crucial for other porous metallic materials, porous tantalum has a
the success of bone defect surgeries, necessitating the higher porosity (75–85%), enhancing tissue permeability
preservation of host bone volume and achieving a good and nutrient exchange within the scaffold, which confers
match between the graft and the bone defect’s anatomical greater potential for osseointegration. 28,29 Balla et al. first
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structure. Previous preoperative planning predominantly reported the additive manufacturing of porous tantalum in
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relied on 2D images, lacking the precision offered by 3D 2010, successfully fabricating a porous tantalum structure
representations of bone defect anatomy. The widespread with a total porosity of 27–55% using Laser Engineered
application of 3D reconstruction and 3D printing Net Shaping (LENS™). The mechanical properties of these
technologies in medicine has made individualized and structures were similar to those of human cortical bone;
precise preoperative planning a reality. With advancements in vitro studies have also demonstrated that laser-treated

Volume 10 Issue 6 (2024) 220 doi: 10.36922/ijb.4074