When Does a Physical Anatomical Model Improve Surgical Planning?

When Does a Physical Anatomical Model Improve Surgical Planning?

Medical teams already use CT and MRI data to obtain detailed views of anatomy. A physical-model workflow should begin with a narrower question: will a tangible, patient-specific representation help the intended group understand, plan, communicate, train or evaluate something that remains difficult to resolve on screen?

Define the task before producing the model: planning an approach, explaining anatomy, rehearsing a step or evaluating a device. Printing the anatomy does not make the model clinically relevant, and the treating team remains responsible for every clinical decision.

Start with the decision the model must support

The strongest requests describe the uncertainty before describing the model. A team may need to understand the relationship between a tumour and nearby vessels, compare possible approaches to an unusual bone geometry, explain a congenital structure to several disciplines or evaluate whether a device envelope can reach its intended position.

Those are different jobs. A model used for visual orientation may only need accurate geometry and clearly differentiated structures. A training model may need tissue-like cutting, suturing or tool-response characteristics. A device-development model may need repeatable interfaces, transparent regions or documented dimensional checkpoints. Patient communication brings another requirement: the model and explanation must be understandable without implying certainty that the evidence does not provide.

Write the model's purpose as a question that can be answered after review. “Can the team see the relationship between these three structures from the intended approach?” is testable. “Make the anatomy more realistic” is not.

Look for a genuine spatial or tactile gap

Screen-based imaging remains the right starting point. It is fast to navigate, supports multiple views and can retain information that would be difficult to reproduce physically. A model earns its place when the physical format closes a specific gap.

Complex three-dimensional relationships are one such gap. Even experienced readers may interpret a series of two-dimensional slices differently, especially when several small or intertwined structures matter at once. A physical model gives everyone the same object, scale and viewpoint. People can point to a region, rotate the model together and test whether their mental pictures agree.

Tactile interaction is another. A rigid visual model can show geometry, but it cannot simulate manipulation. Rehearsal and device interaction make material behaviour part of the brief. Digital Anatomy workflows can combine material regions and anatomical presets for selected tissues, while tools such as Digital Anatomy Creator support the preparation of model behaviour. The required fidelity still has to be matched to the task rather than assumed from a material name.

Define what must be represented

Including every visible structure can obscure the anatomy the team needs to inspect. The model specification should state which anatomy must be included, which structures need visual separation, whether any sections must be removable or transparent, and the required scale.

The imaging data must be suitable for the intended representation. Slice thickness, artefacts, contrast, field of view and segmentation decisions affect the digital geometry before manufacturing begins. The responsible clinical or technical authority must review the segmentation and approve what the model represents. D2M can prepare image data, define the manufacturing workflow and produce the model. The clinical team must decide which anatomy matters and how the model will be used.

For a planning model, document the source dataset, model revision, segmentation owner, review points and intended use. For training or device development, add the target handling behaviour, repeat-use expectations, tool interaction, inspection method and storage conditions. These records keep a visually impressive object tied to its real purpose.

Match fidelity to the application

An accurate rigid model can be enough for orientation and implant sizing discussions as well as education or communication. Colour and transparency can distinguish vessels from bone and lesions from chambers. Removable sections can reveal an internal route without making the whole model clear.

When a reader needs to cut, drill, suture, clamp or deploy a device, geometry alone is insufficient. The brief should name the behaviour, the test method and the reference value used to accept the result. A material that feels convincing in one anatomy or procedure may not represent another. Published test data and controlled evaluations can inform the choice, but the team still needs an application-specific acceptance plan.

The Orthopedic Model Evaluation report, for example, examines screw-driving and pull-out behaviour in a defined bone-model setup. That result supports the specific training or device-development question tested; it should not be applied to other anatomical models without further evidence.

Consider who needs to use the model

A multidisciplinary planning meeting may value a model because it creates a shared reference. A trainee may value repeatability: the same exercise can be prepared for several learners without relying on the availability of a rare specimen. A medical-device team may value controlled geometry because design variants can be compared against a consistent anatomical challenge.

The audience changes the design. Labels and colour boundaries may help teaching but distract from a procedural rehearsal. A model for a meeting may need durability and portability. For a device evaluation, mounting features or replaceable inserts outside the patient anatomy can make the test repeatable.

Confidentiality and governance apply throughout. Patient-derived imaging requires appropriate access controls and transfer methods together with retention rules and approvals. De-identification alone does not define the complete governance route. The organisation responsible for the data should set the policy before files move into a manufacturing workflow.

Know when the screen remains enough

A physical model adds time for segmentation review, file preparation, production, cleaning and quality checks. If the anatomy is straightforward, the decision is urgent, or the team can answer the question confidently with existing imaging and visualisation tools, making a model may add little.

A static model may be unsuitable when the team needs to study motion, blood flow, deformation or another changing condition. Those behaviours can be easier to explore digitally. A hybrid review can use screen-based imaging for navigation and changing views, then bring in a physical model for a defined spatial or tactile task.

Use a short suitability assessment

Before choosing equipment, bring the imaging owner, intended users, technical model team and responsible approval authority together. Confirm the decision, audience, source data, required anatomy, fidelity, delivery window, governance and acceptance checks. Then compare the route with the value of the uncertainty it is intended to reduce.

D2M's medical non-clinical workflow support can help teams assess anatomical-model workflows, prepare a controlled implementation plan and review technology routes such as the J5 Digital Anatomy and J850 Digital Anatomy. The output is a manufacturing and workflow recommendation for the defined application, not clinical advice.

A physical anatomical model can improve planning when it lets the relevant team inspect spatial relationships or rehearse an interaction that is difficult to judge on screen. Write that task into the brief, then test the finished model against it.