Can a small company with an FDM printer make custom orthoses or prostheses?

Only if it becomes a manufacturer of custom-made devices, which is a legal status with obligations, not a question of equipment. That means a written prescription from an authorised person, a quality management system, an Annex XIII statement under MDR, a person responsible for regulatory compliance and, in Slovakia, a notification to ŠÚKL or, in Czechia, to SÚKL. An ordinary print workshop does not meet these conditions, so we do not offer devices for patients.

How does a custom-made device differ from a mass-produced one?

A custom-made device is made to the written prescription of a person authorised by national law, who sets out the design characteristics, and is intended for one specific patient. A mass-produced, adaptable or patient-matched device goes through the standard MDR route with a CE mark and the manufacturer is responsible for it. 3D printing does not make a device custom-made automatically, each case is assessed separately.

Can a 3D printed PLA or PETG part be sterilised in an autoclave?

No, we do not consider them suitable. Steam sterilisation runs at 121 °C (30 minutes) or 132 °C (4 minutes), while Prusa Polymers states a heat resistance of 55 °C for PLA and 68 °C for PETG. A study on PLA at 121 °C for 20 minutes described marked deformation of fine parts, and a sterilisation process must be validated for each device under ISO 17665.

Do ordinary PLA or PETG filaments have proof of biocompatibility?

For the filaments we print with, we hold no such proof. The Prusament safety data sheet gives their use as filament for 3D printing, and the technical data sheets exclude the manufacturer's liability for injuries caused by printed parts. According to the FDA, biological evaluation under ISO 10993-1 (2025 edition) applies to the finished device, not just its material, and pigments, additives and the layered surface remain further variables.

Is a grabber, grip or holder for a person with a disability a medical device?

It depends on the purpose the manufacturer gives the product in its labelling, instructions or advertising. If the object is intended to compensate for a disability, it may be a medical device under MDR, while a universal object with no medical claim is not. We found no statement from ŠÚKL or SÚKL on individual types, and borderline cases are judged by the authority.

What can an FDM workshop make for a medical device manufacturer?

Prototypes, functional samples, production jigs, holders and teaching models without patient data, always to the customer's specification. Conformity of the finished device, assessment of the supplier and validation of processes are the device manufacturer's job, not the workshop's. We do not make devices for patients and hold no ISO 13485 certificate.

3D printed medical devices: limits and regulation

Yes, 3D printing is used in healthcare, but FDM from standard filaments is not enough for a patient device. The limits come from regulation, materials and validation, not a ban on technology. A custom-made device manufacturer needs a quality management system, and steam sterilisation at 121 and 132 °C exceeds the heat resistance of PLA (55 °C), PETG (68 °C) and ASA (93 °C).

We are a small workshop for FDM printing and 3D modelling. We do not offer medical devices for patients, we are not their manufacturer and we hold no ISO 13485 certificate. Under our terms and conditions, our parts are not intended for medical devices without a separate written agreement.

When a product becomes a medical device

What decides is purpose, not technology or place of use. Under Regulation (EU) 2017/745 (MDR) a medical device is an item that its manufacturer intends for use on people for a medical purpose, including diagnosis, monitoring, treatment, alleviation of, or compensation for, an injury or disability (Art. 2(1)). The intended purpose comes from the labelling, the instructions for use and promotional or sales materials and statements (Art. 2(12)), so a sentence on a website can establish it.

Use in a hospital alone is not enough, the Court of Justice of the EU held under the previous directive (C-219/11). A manufacturer is whoever makes a device, or has it designed or made, and markets it under its own name or trademark. Making available on the market includes supply free of charge (Art. 2(27), (28) and (30)).

For household aids such as a grabber, grip or holder, we found no statement from ŠÚKL (Slovakia) or SÚKL (Czechia) on individual types. The purpose the manufacturer gives the product decides, and older guidance (MEDDEV 2.1/1) required a direct link between the corrective function and the person concerned. Borderline cases are judged by the authority: SÚKL in Czechia (Section 6(1) of Act No. 375/2022 Coll.), ŠÚKL in Slovakia, which supervises devices (Section 129 of Act No. 362/2011 Coll.).

Custom-made, patient-matched and mass-produced devices: who is responsible

A custom-made device is a narrow concept in MDR: it is made to the written prescription of a person authorised by national law, who sets out specific design characteristics under their own responsibility, and is intended for one specific patient only (Art. 2(3)). 3D printing does not create one automatically. According to MDCG 2021-3 (Q5 to Q7) the prescription should contain the patient's name or a pseudonym and design characteristics unique to the patient. Dimensions alone or DICOM files from a CT scan are not enough, further measured data or decisions by the prescriber are needed, for example splint thickness or screw positions.

Type of device	Who is responsible	Regulation
Custom-made: to a prescription, one patient (e.g. a KAFO orthosis)	Manufacturer of the custom-made device, design set by the prescription of an authorised person	Annex XIII MDR, statement, no CE mark. Notification to ŠÚKL in Slovakia, SÚKL in Czechia
Patient-matched: matched to anatomy within validated parameters, no prescription (e.g. a surgical guide from DICOM)	Manufacturer	Standard MDR route, CE mark
Adaptable: mass-produced, adjusted at the point of use following the manufacturer's instructions	Manufacturer of the original device. Adapting it for one patient without changing its purpose does not make anyone a manufacturer (Art. 16(1))	Standard MDR route, CE mark
Mass-produced: industrial manufacture	Manufacturer	CE mark

Source: MDR Art. 2(3) and Art. 16, MDCG 2021-3 (Q1, Q5, Q8).

What the manufacturer of a custom-made device must do

A custom-made device carries no CE mark and has no UDI, but the manufacturer meets almost all the other MDR requirements (MDCG 2021-3, Q8):

Quality management system (Art. 10(9)) including risk management, clinical evaluation and the selection and control of suppliers and subcontractors. A workshop that prints for a manufacturer is that manufacturer's subcontractor.
The Annex XIII procedure: a statement for the specific patient, documentation, keeping the statement for 10 years (15 for implants), post-market surveillance and reporting of serious incidents.
Person responsible for regulatory compliance (PRRC): expertise can be shown by two years of experience in the relevant field. Micro and small enterprises need not employ the person, but must have them permanently and continuously at their disposal (Art. 15).
Financial cover for liability proportionate to the risk class, type of device and size of the enterprise (Art. 10(16)).

Slovakia. The manufacturer of a custom-made device must notify ŠÚKL of making it available in Slovakia (Section 110b(8) of Act No. 362/2011 Coll.). The procedure is set out in ŠÚKL guidance MP 152/2026 (point 5.4, effective from 16 April 2026). ŠÚKL has announced a separate guidance for custom-made devices, so check the current procedure with it.

Czechia. A custom-made device manufacturer based in the Czech Republic must, under Section 8(4) of Act No. 375/2022 Coll., report through the Information System of Medical Devices the start of activity within 30 days of starting production, a list of generic groups within six months and the end of activity.

Why FDM runs into limits

FDM is not banned in medicine: the FDA lists fused filament fabrication, the FDM principle, among the four most commonly used technologies in medical devices (FDA, 2017). The limits lie in what has to be demonstrated.

Limit	What the sources say	What follows
Temperature and sterilisation	Prusa Polymers: PLA 55 °C (PLA), PETG 68 °C, ASA 93 °C. Steam sterilisation: 30 min at 121 °C or 4 min at 132 °C (CDC)	Both temperatures are above these values. At 121 °C for 20 minutes fine PLA parts deformed markedly in a study
Layers and cleaning	According to Prusa the grooves between layers are hard to clean and hold residues (the text is about food, the mechanism is the same)	Without a validated cleaning process, a reusable surface cannot be relied on
Filament without a medical declaration	The Prusament safety data sheet gives the use as filament for 3D printing, and the technical data sheets exclude liability for injuries. According to the FDA, biological evaluation under ISO 10993-1:2025 applies to the finished device	Pigments and additives are unknown variables
Layer direction and validation	Interlayer adhesion: PETG 18 MPa, ASA 11 MPa, values depend on print settings and operator experience. The FDA expects control of input materials and documented post-processing (non-binding, American guidance)	Worst-case orientation must be tested on the finished part after cleaning and sterilisation. The device manufacturer must prove reproducibility

The PETG and ASA temperatures are heat deflection temperatures (HDT, ISO 75) from the technical data sheets (PETG, ASA). HDT is a comparison test under load, not a melting point or a permitted temperature, more in Material for 3D printing under heat and load. Sterilisation is decided by validation under ISO 17665. For ASA, nylon and TPU we found no data on steam sterilisation, so we claim nothing about them.

The authors of that PLA study also state that the inherent sterility of printing should not be relied on in patients. With hydrogen peroxide plasma, another study measured deformation below 0.2 mm on one type of PLA and PETG surgical guide.

Not every device must be sterilised: under the Spaulding classification, non-critical devices on intact skin, such as crutches, are only cleaned and disinfected. Even that is a load: in Prusa's tests PETG and ASA lost tensile strength after a week in ethanol or isopropanol (immersion is not wiping, so treat it as a warning). Materials are compared in Which material to choose for 3D printing and Materials for 3D printed end-use parts.

What a small workshop can honestly do, and what it cannot

Final responsibility and legal assessment stay with the device manufacturer. A workshop supplies a part to its specification and claims nothing about conformity.

We can make:

Prototypes and functional samples for developers. A prototype that is not made available on the market falls outside MDR by our reading (Art. 2(27) and (28)). Use on a patient or in a clinical investigation belongs to a different regime. Ordering works as for 3D printing prototypes.
Production jigs, templates, fixtures and holders for device manufacturers. On their own they have no medical purpose, and the manufacturer, who must control suppliers (Art. 10(9)(d)), is responsible. Some may reject a supplier without a certificate.
Teaching models outside clinical decision-making, printed from a generic model, not patient data, and marked as not a medical device. The EU gives no authoritative guidance on this boundary, which depends on purpose (Pettersson et al., 2024), so we keep it strict.
3D modelling and model preparation for printing to your specification (3D modelling).

We do not make:

custom orthoses, prostheses, splints or insoles for a patient, or patient-matched devices such as surgical guides and implants,
parts intended for contact with a patient, for sterilisation or for implantation, and components intended to be built into a device, which may themselves be devices (MDCG 2021-3, Q2 and Q3),
models for planning a procedure and work with patient images or scans: health data is a special category under the GDPR (Art. 9) and our privacy policy says we do not process it,
claims of conformity: we hold no ISO 13485 certificate and our materials have no biocompatibility certification.

If you are a device manufacturer looking for prototypes or fixtures, write to us about what the part is for. A device for a patient will be made by a manufacturer that meets MDR, not by our workshop.

What to check before ordering 3D printing with a medical use

The starting point is a prescription from a person authorised by national law, not an order with a print workshop. If a print will end up with a patient or in a clinical setting, go through these points before sending the model:

Purpose. If it is for diagnosis, treatment, compensating a disability or contact with a patient, you are ordering a device, not an ordinary part.
Manufacturer. Who will place the device on the market under their own name, with a quality management system and a ŠÚKL or SÚKL notification?
Prescription and documentation. Is there a prescription with characteristics for the specific patient (dimensions or CT alone are not enough) and an Annex XIII statement?
Material. Does the filament manufacturer give proof for medical use, and was the finished device evaluated under ISO 10993-1:2025?
Cleaning and sterilisation. Which process will be used, can the material and shape withstand it, and is the process validated?
Process and supplier. Are orientation, parameters and finishing documented and verified on the finished part, and has the manufacturer assessed the workshop as a subcontractor?
Patient data. Does the workshop receive only a model without personal data? Health data needs a legal basis and a contract.
Claims. No misleading statements about the device, for example about conformity or properties without evidence (Art. 7 MDR).

A brief with no medical purpose is an ordinary order, as in Ordering a 3D printed prototype.

Sources and currency

We verified the legal texts and technical data on 1 October 2026. This is not legal advice or an authority's statement, and regulations change. On 16 December 2025 the Commission put forward a proposal to revise MDR (COM(2025) 1023), which would change Art. 15 (small enterprises would no longer need the person responsible for regulatory compliance permanently and continuously at their disposal) and Art. 86 (periodic safety update reports would not apply to custom-made devices). It does not change the definition of a custom-made device. We have not confirmed its adoption, so we work from the current text.

Sources are linked at each claim. We checked only the status and scope of the ISO standards (ISO 13485:2016, ISO 10993-1:2025, ISO 17665:2024), not their texts.

This article was prepared by the 3D tlač na zákazku editorial team with the help of AI tools. Every text goes through expert and editorial review, the figures are verified against the sources cited in the article, and we hold editorial responsibility for the published content. If you spot an inaccuracy, let us know.

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