Critique and considerations on 3D printing in complex pelvic and acetabular fractures

Dear Editor,

We read with considerable interest the article by Kai-Xing Alvin Lee and colleagues, ¹ “3D simulation and printing for complex comminuted pelvic and acetabular fractures: A single-center experience,” published in a recent issue of the Journal of Orthopaedic Surgery. This study offers valuable insights into the utility of 3D simulation and printing technology in managing highly challenging pelvic and acetabular fractures. We commend the authors for their diligent investigation into a rapidly evolving and promising area within orthopedic trauma surgery.

The introduction of novel simulation algorithms, specifically mesh grid optimization and bone density evaluation, represents a significant methodological advancement. The ability to strategically plan hardware placement based on bone density offers a theoretical advantage, particularly in cases with compromised bone quality or extensive comminution. Such precision could potentially mitigate the risk of screw loosening and other hardware-related complications, thereby enhancing the stability of internal fixation.

However, the study’s primary conclusion—that 3D printing did not demonstrate a statistically significant improvement in major clinical outcomes such as postoperative complications or the need for total hip arthroplasty (THA)—warrants further discussion. While initial analyses showed numerical improvements in EQ-VAS and Majeed Pelvic Scores in the 3D printing group at 2 years, these differences were attenuated and lost statistical significance after adjusting for critical confounders such as chronic kidney disease (CKD) and hypertensive cardiovascular disease (HCVD). This raises important questions about the direct and quantifiable clinical benefits of 3D printing beyond its acknowledged utility in preoperative planning.

A notable limitation, as the authors appropriately acknowledge, lies in the study’s retrospective, single-center, non-randomized cohort design, particularly the patient selection process driven by self-funded choice for 3D printing. This introduces a significant potential for selection bias. Patients willing to bear the financial cost of 3D printing may represent a distinct demographic with differing socioeconomic backgrounds, higher health literacy, or even unmeasured intrinsic factors that could influence perceived quality of life outcomes. Such inherent biases are challenging to fully account for in non-randomized settings.

Furthermore, the omission of reduction quality assessment on computed tomography (CT) scans is a critical oversight. In the context of complex pelvic and acetabular fractures, the anatomical restoration achieved during surgery is a paramount indicator of successful intervention, directly correlating with long-term functional outcomes and the incidence of post-traumatic osteoarthritis and subsequent THA. Neglecting this objective metric could obscure a fundamental aspect of the intervention’s efficacy.

We concur with the authors’ call for more robust research designs, particularly large-scale, multicenter randomized controlled trials (RCTs), to definitively evaluate the efficacy of 3D printing. RCTs are essential to minimize bias and ensure rigorous control over confounding variables. Future studies should also consider disaggregating pelvic and acetabular fractures in their analyses, as distinct anatomical regions may respond differently to advanced planning. Moreover, objective quantification of reduction quality and an exploration of how 3D printing benefits surgeons of varying experience levels would provide invaluable insights.

In summary, Lee and colleagues’ study contributes meaningfully to the ongoing discourse regarding 3D printing in orthopedic trauma. While their findings did not unequivocally establish direct clinical superiority, we maintain that the technology holds considerable promise. Future investigations must address the inherent methodological limitations of early studies to provide the conclusive evidence needed to fully integrate 3D printing into standard clinical practice for complex fracture management.