Medical applications of 3D printing — field notes from the UANL biomedical lab

Context

None of these projects were mine alone. They are the output of a working group — engineers, residents, attending surgeons, and the imaging department — collaborating across roles. This note documents what we did together; credit belongs to the team.

Between 2015 and 2020, I was part of GIDIB — Grupo de Innovación y Desarrollo en Ingeniería Biomédica at the Centro de Ingeniería Biomédica del Hospital Universitario "Dr. José Eleuterio González" (UANL Faculty of Medicine), within the 3D-printing track. The group sat at the intersection of biomedical engineers, residents, attending surgeons, and radiology — in close collaboration with the Centro Universitario de Imagen Diagnóstica, UANL Facultad de Medicina.

The presentation that anchors this note was delivered with three core collaborators:

• Ing. Rafael Eduardo López Barrón
• Dr. Adrián A. Negreros Osuna
• Dr. Antonio Sánchez Uresti

It covered the program's four working areas: education, training, surgical planning, and custom guides/molds.

Additive manufacturing — the short version

Additive manufacturing builds three-dimensional solid objects layer-by-layer from a digital model. The patent that opened the field belongs to Chuck Hull (US4575330, 1984).

For medical work the lab used three families of printers: FDM (Fused Deposition Modeling — Zortrax M200 and Prusa-class machines), SLA (Stereolithography — Formlabs Form 2), and PolyJet (Stratasys, FDA-cleared workflows).

Common materials: PLA (biodegradable thermoplastic, ~190–230 °C, prototypes and educational models) and ABS (~210–250 °C, durable, load-bearing, heat-resistant). For sterilizable workflows, the group ran steam sterilization validation on selected parts.

Where 3D printing was applied at our center

Four use-cases ran in parallel. Each one solved a specific problem the operating room or the classroom was already struggling with.

1. Educational models

Tangible anatomy that students could rotate, palpate, and disassemble. The point was never to replace cadaveric work; it was to give trainees something they could hold before the cadaver lab, and to standardize the reference anatomy across cohorts.

A multi-part hand with articulated phalanges ^[1] served as a tactile entry point for upper-limb anatomy. A segmented cardiac vasculature model ^[2], printed in red PLA from real imaging, became the coronary-anatomy reference across two cohorts. Print times stayed within a 6–10 hour overnight window, which is what made the workflow sustainable for a teaching service.

2. Training models

Models designed for hands-on procedural practice — not just visual reference. These are the kind of artifact that compresses a long learning curve into a few supervised sessions.

A translucent vascular trainer ^[3] built from segmented imaging let residents rehearse catheter-based and surgical skills before the patient. For spine work, the lumbar vertebra was first segmented with trajectory planning for a transpedicular screw ^[4], then printed so residents could practice the actual placement ^[5] — trajectory, depth, torque — before doing it on a patient.

3. Surgical planning

Pre-operative models printed from the patient's imaging — so the surgical team can rehearse the case before the case. A 6–10 hour print can save much longer in the OR, plus the strategic clarity it gives the team going in.

Complex acetabular fracture. The CT was segmented to separate fracture fragments from intact bone ^[6], then printed at 1:1 ^[7]. The orthopaedic team studied fragment geometry and pre-bent hardware against the model before incision.

Maxillofacial reconstruction. Imaging was the starting point for both the planning model and the custom implant geometry ^[8]. Patient anatomy and a designed implant geometry were rendered together ^[9] so the implant matched the missing bone segment before going to print. The final printed planning model — anatomy in cream, reconstruction piece in gray ^[10] — was handled by the surgical team to validate fit and approach.

4. Custom surgical guides and molds

Patient-specific physical tools, printed and sterilized.

• Custom implant design — patient-specific implant geometry derived from segmented imaging.
• Fibula segmentation guide — printed cutting guide for fibula osteotomy in reconstruction.
• Sterilization process — validated steam sterilization for surgical-environment parts.

The most consequential outcome the program tracked was a complex reconstruction case where the use of a printed mold and pre-operative planning model reduced surgical time from approximately 20 hours to 12 hours. The specifics of that case are not shown here by design — the takeaway is the workflow, not the patient.

What 3D printing actually does for a clinical team

Four things, ordered by how often they pay off:

1. Compresses learning curves — a trainee handles the structure before the procedure.
2. De-risks the operating room — the surgeon has already done the difficult step on a tactile model.
3. Cuts operating time — fewer intra-operative decisions, less improvisation.
4. Personalizes the implant or guide — the part matches the patient, not the average patient.

Limits and honesty

Not every case warrants a printed model. Print time, post-processing, segmentation work, sterilization validation, and material cost are real. The right question is never "can we print this?" — it is "does printing this change the decision or the outcome enough to be worth the workflow?"

For the cases above, the answer was yes. For many others the answer would be no, and the discipline is to say so.

Special thanks

To the three collaborators who co-authored the work this note is built on:

• Ing. Rafael Eduardo López Barrón
• Dr. Adrián A. Negreros Osuna
• Dr. Antonio Sánchez Uresti

And to the institutions that made the work possible — the Universidad Autónoma de Nuevo León, the Facultad de Medicina, UANL, the Departamento de Ingeniería Biomédica, UANL, the Centro Universitario de Imagen Diagnóstica (UANL, Facultad de Medicina), and GIDIB — Grupo de Innovación y Desarrollo en Ingeniería Biomédica.

These people and these places have been a fundamental part of my professional development. I am enormously grateful to have crossed paths with them, and to have learned as much as I did from each one.

Reference

Presentation: Aplicaciones Médicas de la Impresión 3D — M.I.P. Enrique Aguilar Martínez, GIDIB-Impresión 3D, Centro de Ingeniería Biomédica, Hospital Universitario "Dr. José Eleuterio González", UANL · 2015–2020 group affiliation.

Key literature cited in the deck:

• Chepelev, L. et al. (2017). Medical 3D printing: methods to standardize terminology and report trends. 3D Print. Med. 3, 4.
• Dudek, P. (2013). FDM 3D printing technology in manufacturing composite elements. Archives of Metallurgy and Materials, 58(4), 1415–1418.
• Excell, J. (2010). The rise of additive manufacturing. The Engineer.