Custom-made and biodegradable implants: what patents tell us about the future of orthopedics

Custom-made and biodegradable implants: what patents tell us about the future of orthopedics

3D printing is not only changing the way orthopedic implants are manufactured: it is redefining what an implant can do, how long it lasts, and how much surgery it requires for the patient. Thanks to hybrid manufacturing techniques and biodegradable materials, customized orthopedic implants could soon offer greater safety and less invasiveness, without having to wait decades to get there.

Patents cited

• ADDITIVE MANUFACTURING ON MACHINED ASSEMBLED PARTS — January 28, 2026
• SCAFFOLD WITH STEM CELLS — March 18, 2026

What problem does it solve

Traditional orthopedic implants often require multiple surgeries and do not integrate perfectly with the patient's bone.

In the field of orthopedic and trauma surgery, one of the most common problems is the need for a second surgical procedure to remove plates, screws, and fixation devices after the bone has healed. This procedure exposes the patient to additional risks, increases healthcare costs, and lengthens overall recovery times. The ideal solution is a temporary implant capable of mechanically supporting bone tissue during the healing phase and then gradually dissolving in the body, eliminating the need for a second operation.

At the same time, the surface quality of 3D-printed implants is often lower than that obtainable with traditional machining techniques, which can compromise the assembly of complex components and integration with bone tissue. While 3D printing makes it possible to create porous structures that promote bone growth, mechanical machining ensures precise and reliable surfaces. Combining the two approaches could offer the best of both worlds.

The idea in 60 seconds

By combining pre-machined mechanical parts with 3D-printed porous structures, customized and highly integrable implants are obtained.

The patent ADDITIVE MANUFACTURING ON MACHINED ASSEMBLED PARTS describes a hybrid process: first, solid components manufactured with traditional techniques (turned, milled) are assembled, then a porous structure is 3D printed directly onto them. The result is an implant that integrates the mechanical precision of the machined parts with the geometric flexibility of additive manufacturing.

The implant may include a central opening with straight and curved sides, segments with coaxial holes for intraoperative imaging instruments, and a solid outer structure printed around a porous core to ensure structural integrity. The internal hollow region can be filled with bone graft to accelerate fusion and bone growth. The porous part can be made of porous titanium with an external solid titanium frame for reinforcement, using technologies such as electron beam melting (EBM), selective laser sintering (SLS), or selective laser melting (SLM).

On the biodegradable materials front, zinc occupies an intermediate position between magnesium (which degrades too quickly) and iron (too slowly): it has a degradation rate compatible with the biological timescales of bone healing, is naturally present in the human body, and participates in fundamental cellular functions such as immune response and bone mineralization.

The SCAFFOLD WITH STEM CELLS patent instead proposes a radically different approach: a scaffold composed of 60% biomaterial (silicone, polyglycolic acid, xanthan gum, NaCl, agar, carbon fullerene C60, and water) and 40% cellular materials, mainly mesenchymal stem cells of adipose origin (50%), hyaluronic acid (30%), and TGF-beta (20%). The material has a rubbery consistency and can be stimulated from the outside to promote cell growth, progressively replacing the biodegradable material with biological tissue.

What really changes (tangible improvements)

Mechanical precision + geometric flexibility = better bone integration and fewer post-operative revisions.

The hybrid approach described in the first patent improves the precision of critical surfaces through the use of pre-machined mechanical components, while allowing complex internal geometries without sacrificing robustness. The cavities that can be filled with bone graft accelerate fusion, while the porous structure promotes osseointegration. This means fewer post-operative complications and better distribution of mechanical load.

A study published in March 2026 in the Journal of Functional Biomaterials investigated the feasibility of producing customized biodegradable implants from zinc alloys with silver and copper, using laser powder bed fusion 3D printing technology (L-PBF). The study, conducted by Tübingen University Hospital and the fem Research Institute in Schwäbisch Gmünd, tested three alloys: ZnAgCu, ZnAgCuMn, and ZnAgCuTi.

The ZnAgCuMn alloy proved to be the one with the best biological performance in freshly polished samples, thanks to the lower release of Zn²⁺ ions and the co-release of small amounts of Mn²⁺, which the literature associates with positive effects on osteoblast proliferation. The ZnAgCuTi alloy, on the other hand, consistently showed the lowest biological performance.

A critical aspect that emerged from the study concerns surface aging: polished samples stored in air for 3 months showed significantly lower cytocompatibility than freshly polished samples. For ZnAgCu, proliferation dropped from 36,2% (fresh) to 8,3% (aged); for ZnAgCuMn from 56,6% to 42,9%. This indicates that packaging, sterilization, and storage strategies for implants will have a direct impact on the biological response.

As for cellular scaffolds, the ability to degrade in situ reduces the need for secondary interventions, while the programmed release of growth factors promotes a controlled biological response. However, the available sources do not provide quantitative data on degradation times or clinical success rates.

Esempio in azienda / sul mercato

Already today, some surgical centers are testing hybrid prototypes in the operating room.

The New York-based company Himed has developed an innovative hydroxyapatite (HA) surface finishing process for the 3D-printed medical implant market. Hydroxyapatite is a calcium phosphate naturally present in bones and teeth, commonly used as a blasting medium for surface preparation and as a coating to encourage osseointegration.

Himed's process uses hydroxyapatite as a blasting medium that can both remove unwanted residual beads from powder-based 3D printing and improve the biocompatibility of printed medical devices. Unlike aluminum oxide, traditionally used but subject to fragmentation and incorporation into the material, HA can be completely removed with a passivation process, leaving only a clean surface.

OsseoLabs, a company that combines AI-guided surgical planning with next-generation bioresorbable implants, is already testing bioresorbable magnesium implants that provide mechanical support only during the critical healing phase and then safely resorb. OsseoMatrix™ TPMS (Triply Periodic Minimal Surface) architectures promote superior bone growth and reduce stress shielding. The OsseoVision™ system allows surgeons to digitally plan the procedure, review fixation strategies, and confirm implant placement in advance, often reducing operating times by 30-50% in complex cases.

Materialise has recently launched custom 3D-printed PEEK CMF (cranio-maxillofacial) implants, expanding the material options available for personalized surgery. Custom 3D-printed scaffolds for the regeneration of critical bone defects are already the subject of pilot clinical studies, for example for bone reconstruction in dentistry and maxillofacial surgery, showing good integration, bone volume increase, and a reduction in the number of necessary procedures.

Trade-offs and limitations

Hybrid processes complicate production and increase quality control requirements; some biological solutions remain at high regulatory risk.

Quality control of joints between machined and printed parts represents a significant challenge. The preferential volatilization of zinc during L-PBF can shift the chemical composition over time, especially with powder reuse. The post-degradation mechanical properties of implants as they degrade have not yet been comprehensively evaluated.

For cellular scaffolds, the long-term stability of the living material during storage and implantation remains an unknown. The complex regulation associated with the use of human stem cells represents a significant obstacle to widespread clinical adoption. The clinical introduction of shape-memory scaffolds for infected defects still requires extensive preclinical and clinical testing, with particular attention to safety, degradation kinetics, drug release, and long-term mechanical reliability.

From a regulatory standpoint, the use of already known and biocompatible materials can partially simplify the pathway, while complex combinations of devices and drugs require more complex authorization processes.

Reality check: what is needed to reach production

Extensive clinical validations and standardization of hybrid production processes are still necessary.

Before any clinical application, numerous questions remain open. In vitro tests are not sufficient to predict the complete tissue response (inflammation, healing, mechanical integration) over weeks or months. Production process control must be standardized, especially with regard to the management of metal powders and the repeatability of printing parameters.

Post-processing strategies must be optimized to ensure that the surface of implants maintains its biological properties over time. Surface aging has been shown to have a significant impact on cytocompatibility, which implies the need to develop specific packaging and storage protocols.

For hybrid approaches, the estimated adoption horizon is 2-5 years, while for stem cell-based solutions it is 5+ years. However, these timelines depend heavily on how quickly clinical validations are completed and regulatory approvals obtained.

New technologies show a plausible path toward smarter and less invasive implants, albeit with significant obstacles still remaining. The mix of advanced engineering and biology could redefine orthopedics in the coming years, bringing tangible benefits in terms of reducing secondary interventions, better bone integration, and patient-specific customization. Follow the developments: the convergence of hybrid manufacturing, biodegradable materials, and cell therapies is already shaping the future of orthopedic implants.

article written with the help of artificial intelligence systems