prosthesis
Enable an AI agent to recognise a prosthesis, assess its recorded suitability and condition for its intended replacement role, and identify actions permitted by its fitting, clinical and maintenance constraints.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise a prosthesis, assess its recorded suitability and condition for its intended replacement role, and identify actions permitted by its fitting, clinical and maintenance constraints.
A manufactured medical device that substitutes for an absent or deficient body part, restoring some combination of load-bearing function, motor control, and appearance, whether worn externally at a residual-limb or mucosal interface (the ISO 8549 sense) or implanted or seated as an endoprosthesis, dental restoration, ocular form, or other anatomical replacement.
It can be Identify the replacement target, recipient association and installed configuration.; Compare documented fit and performance evidence with the intended replacement role.; Check proposed components, attachments and accessories against recorded compatibility constraints.; Identify applicable instructions and prerequisites for donning, removal, cleaning, charging or storage.; Record symptoms, interface changes or device faults and route them to the appropriate assessment process.; Determine whether a proposed adjustment, repair, continued use or replacement has the required authority and supporting evidence..
Distinguishing features
An intended replacement role can be stated: which body part or anatomical portion it substitutes for and in what respect.
Its intended role includes substitution for a body part, rather than solely supporting, aligning or protecting a retained part; hybrid cases require explicit classification.
It is an engineered physical device rather than transplanted biological tissue; mixed constructions require a recorded boundary.
Its intended use identifies a bodily placement or attachment relationship, distinguishing it from an anatomical teaching replica.
Functional restoration is not the sole qualifying test: a device intended to replace bodily appearance may qualify even when it supplies no movement or load-bearing function.
Scope
+ The body part, anatomical extent and side the prosthesis is intended to replace
+ External, removable and implanted configurations, including their constituent replacement components
+ Interfaces with the body and with attachment, retention or supporting systems
+ Intended functional and appearance outcomes and evidence of achieved performance
+ Fit, integrity, cleanliness, serviceability and restrictions on use or intervention
- The recipient's complete clinical history, diagnosis and treatment plan
- Surgical procedures, rehabilitation programmes and clinician competency records
- Orthoses whose primary role is supporting or correcting a retained body part
- Standalone mobility aids and other assistive equipment that do not replace a body part
- Biological grafts and transplanted organs
- Manufacturing facilities and general inventory, procurement or reimbursement processes
Characteristics
- Replacement target
- Body part or anatomical portion, anatomical site and laterality where applicable Establishes what makes this device a prosthesis and prevents confusion between incompatible sites or sides.
- Replacement role
- Load transfer, movement, articulation, fluid passage or containment, sensory contribution, appearance, other specified role; multiple values allowed Determines which capabilities and limitations are relevant without assuming all prostheses perform the same function.
- Placement and removability
- External or implanted; recipient-removable, practitioner-removable or removal requiring a procedure; unknown Controls which inspection, cleaning, adjustment and removal actions may be considered.
- Recipient and fitting association
- Assigned recipient, intended site and applicable fitting or implantation record; unassigned or unknown Separates device identity from evidence that this particular configuration suits a particular recipient.
- Body interface and retention
- Recorded contact surfaces and retention or fixation mechanisms, with applicable mating components Identifies where attachment, pressure, movement or compatibility problems can arise.
- Fit assessment
- Not assessed, acceptable for a specified context, adjustment required, unacceptable or unknown; dated assessment and assessor Makes suitability contextual and traceable rather than treating possession or attachment as proof of fit.
- Performance envelope
- Role-specific measures and units, such as load in N, motion in degrees or flow in mL/min, with test conditions; not applicable or unknown Connects intended replacement function to documented limits and observed performance.
- Actuation and energy dependence
- Passive, body-powered, externally powered or other specified mechanism; energy source and operating dependencies where applicable Identifies whether replacement function depends on power, control inputs or other supporting equipment.
- Integrity and service state
- Assessed serviceable, degraded, failed, awaiting assessment or retired; affected component and evidence Distinguishes physical damage from poor fit and identifies whether repair, replacement or further assessment is needed.
- Use authorisation
- Pending assessment, authorised for recorded conditions, restricted, withdrawn or unknown; authority and supporting record Prevents an agent from inferring permission to use a device solely from apparent physical condition.
Also called
+37
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.prosthesis
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 32 questions.
Replacement identity Establishes what bodily absence or deficiency the device addresses and the boundary of the prosthesis being modelled.
A prosthesis is recognised through its intended bodily substitution, not through material, shape or powered operation alone.
Anatomical substitution
Records the target anatomy and the respects in which the prosthesis substitutes for it.
Replacement target and role
The record must distinguish anatomical replacement from the particular functions or appearance the device is intended to provide.
- Which body part or anatomical portion, site and side is this prosthesis intended to replace? definition
- Which functions or appearance attributes are intended to be substituted, and which are explicitly not provided? boundary
Prosthesis boundary
Distinguishes the complete prosthesis from its components, bodily supports and neighbouring device categories.
Device extent and classification
The record must explain what counts as this prosthesis, including any hybrid replacement and support roles.
- Does this record identify a complete prosthesis, a replacement component or an assembly, and which parts belong within its boundary? boundary
- What documented intended purpose distinguishes it from an orthosis, assistive aid, graft or anatomical replica? provenance
Bodily integration Describes placement, retention and the evidence connecting this configuration to its recipient.
Replacement capability depends on the prosthesis's relationship with the body, and cannot be established from the device specification alone.
Contact and fixation
Records bodily contact, load or motion transfer, and retention or fixation mechanisms.
Interface arrangement
The model must identify the interfaces through which the prosthesis remains positioned and performs its replacement role.
- Where does the prosthesis contact or connect to the body, and how is it retained or fixed at each interface? definition
- Which retained tissues, implants, sockets, abutments or other supports does that arrangement depend on? boundary
Recipient-specific fit
Connects suitability to a recipient, configuration, assessment date and intended activity or condition.
Fit evidence and change
Fit must be represented as an evidenced, time-dependent relationship rather than an intrinsic permanent property.
- Who assessed fit for this recipient and configuration, when, and for which intended conditions of use? provenance
- What recorded observations indicate a change in contact, retention, alignment, comfort or surrounding tissue since that assessment? measurement
- Which documented changes require reassessment before further use or adjustment? action
Replacement performance Captures intended outcomes, observed performance and dependencies required to deliver them.
Different prostheses replace different aspects of anatomy, so useful state assessment must follow the specific replacement role.
Role-specific capability
Describes performance using measures appropriate to the replaced function or appearance.
Capability evidence
The record must separate intended capability, documented limits and observed outcomes.
- Which measures or assessment criteria establish whether this prosthesis delivers its intended replacement function or appearance? measurement
- Under what test or use conditions were those outcomes observed, and how do they relate to documented operating limits? provenance
Control and dependencies
Records how replacement function is produced and what happens when supporting inputs are unavailable.
Functional dependency state
Applicable power, control, calibration and supporting-component dependencies must be linked to the functions they enable.
- Which functions are passive, body-powered or externally powered, and what control inputs or supporting components do they require? definition
- What documented behaviour and permitted response apply if power, control, calibration or a required supporting component is unavailable? action
Configuration and condition Tracks the fitted assembly and evidence of physical or hygienic changes affecting bodily replacement.
A component substitution, wear pattern or contact-surface change can alter the suitability of a prosthesis even when its overall identity stays the same.
Fitted configuration
Identifies components and settings that define the configuration assessed for use.
Configuration traceability
The current assembly must be distinguishable from earlier or proposed configurations and linked to relevant compatibility evidence.
- Which components, sizes, materials, alignment settings and software versions, where applicable, define the current fitted configuration? definition
- What evidence supports compatibility among these components and the recipient's attachment or fixation arrangement? provenance
- Which proposed substitutions or setting changes require a new fitting, calibration or clinical assessment? action
Degradation and cleanliness
Records observable condition and assessment limits for accessible and inaccessible parts.
Condition evidence
Condition assessment must identify affected parts and distinguish direct observations from reports or indirect evidence.
- What evidence records wear, cracking, loosening, leakage, corrosion, contamination or other degradation relevant to this prosthesis? measurement
- Which surfaces or internal parts cannot be directly inspected, and what assessment method or uncertainty is recorded for them? boundary
- What cleaning, servicing or specialist assessment is specified for the affected interface or component? action
Permitted use and intervention Connects use, handling and intervention decisions to applicable instructions and responsible authorities.
External removable and implanted prostheses permit very different actions, and apparent serviceability does not establish permission to intervene.
Use context and handling
Defines authorised use conditions and actions available to the recipient, caregiver or practitioner.
Use and removal constraints
The model must retain device-specific conditions governing activity, handling and removal.
- Which activities, environments and exposure conditions are permitted or restricted by the applicable instructions and recipient-specific assessment? boundary
- Who may fit, don, remove, clean, charge or adjust this prosthesis, and what prerequisites apply to each relevant action? action
Reassessment and disposition
Records how concerns lead to review, servicing, replacement or retirement without presuming those actions are interchangeable.
Intervention decision
Proposed interventions must be linked to the observed concern, applicable instructions and the authority responsible for the decision.
- What evidence and responsible authority support the current decision to continue use, restrict use, seek assessment, repair, replace or retire the prosthesis? provenance
- What documented response applies to the reported malfunction or bodily-interface concern, including whether removal itself requires a practitioner or procedure? action
- What verification is required before the prosthesis returns to use after an adjustment, repair or component replacement? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Lower-limb (partial-foot, transtibial, knee-disarticulation, transfemoral, hip-disarticulation/hemipelvectomy)
- Upper-limb (partial-hand, transradial, transhumeral, shoulder-disarticulation; passive, body-powered, myoelectric, hybrid)
- Activity-specific limb devices (running blades, swim, occupational/tool terminals)
- Joint-replacement endoprostheses (hip, knee, shoulder, and related arthroplasty implants)
- Dental and maxillofacial prostheses (fixed, removable, implant-supported; obturators and facial restorations)
- Ocular and orbital prostheses
- Breast and other soft-tissue prostheses (external forms and implants)
- Cardiac valve and vascular prostheses
- Which of these kinds and varieties hold for the sense of prosthesis this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q181802 - Item 'prosthesis'; narrower items exist for limb, dental, ocular, and joint kinds.
- SNOMED CT - 53350007 - Prosthesis, device (physical object); descendants cover anatomical and implant subtypes.
- MeSH - D011474 - Prostheses and Implants (broader heading that also covers implants).
- ISO 9999 - 06 18 / 06 24 - Upper-limb and lower-limb prostheses under class 06 Orthoses and prostheses; dental, ocular, and implants sit elsewhere.
- HS / Harmonized System - 9021.21 / 9021.31 / 9021.39 - Artificial teeth; artificial joints; other artificial parts of the body.
- HCPCS Level II - L5000-L5999; L6000-L6999; L8000-L8039 - U.S. billing codes for lower-limb, upper-limb, and external breast prostheses.
- FDA product code - ISW (and related 21 CFR 890 prosthetic codes) - External assembled lower-limb prosthesis family; joint implants are coded under 21 CFR 888.
- Which of these identifiers and schemes hold for the sense of prosthesis this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- ISO 8549 series (ISO) - vocabulary for external limb prostheses and orthoses
- ISO 10328 (ISO) - structural testing of lower-limb prostheses
- ISO 22675 (ISO) - cyclic testing of ankle-foot devices and foot units
- ISO 22523 (ISO) - requirements and test methods for external limb prostheses and orthoses
- ISO 13405 series (ISO) - classification and description of prosthetic components
- ISO 21534 / 21535 / 21536 and ISO 7206 / 14243 (ISO) - joint-replacement implant requirements and test methods
- ISO 5840 series (ISO) - cardiac valve prostheses
- Regulation (EU) 2017/745 MDR (European Union) - medical-device placing on the market, including implantable prostheses
- 21 CFR 890 Subpart D and 21 CFR 888 (U.S. FDA) - physical-medicine prosthetic devices and orthopaedic implants
- WHO standards for prosthetics and orthotics (World Health Organization, 2017) - service provision rather than device design
- Which of these standards and regulation hold for the sense of prosthesis this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Fitted after amputation for dysvascular disease, trauma, tumour, or infection, or for congenital limb difference, then used for standing, walking, grasping, or cosmesis in daily life.
- Total hip and knee replacements implanted for osteoarthritis, fracture, and revision arthroplasty.
- Removable dentures, crowns, bridges, and implant-supported restorations replacing missing teeth.
- External silicone breast forms after mastectomy, and implanted breast prostheses in reconstruction or augmentation.
- Custom ocular prostheses after evisceration or enucleation; craniofacial restorations after tumour or trauma.
- Mechanical and bioprosthetic heart valves implanted for valvular disease.
- ICRC-type polypropylene modular limbs and Jaipur-style feet in conflict, disaster, and low-resource programmes.
- Paralympic and recreational sport (running blades, activity-specific terminals) as a distinct fitting pathway.
- Which of these real-world use hold for the sense of prosthesis this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Mass of a complete adult transtibial prosthesis - 1.0-2.5 - kg
- Mass of a complete adult transfemoral prosthesis - 2.0-4.5 - kg
- User body mass covered by common ISO 10328 structural load levels - 45-125 - kg
- Peak socket-residual-limb interface pressure - 100-350 - kPa
- Hip femoral-head diameter (modular endoprosthesis) - 22-36 - mm
- Heart-valve labelled tissue-annulus size - 19-33 - mm
- External breast-form / implant fill volume - 150-700 - mL
- Community-ambulator walking activity - 2000-7000 - steps/day
- Which of these typical measurements hold for the sense of prosthesis this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Socket misfit and residual-limb volume change causing pistoning, skin breakdown, blistering, or pressure injury.
- Suspension failure and falls from alignment error, prosthetic-knee instability, or foot/keel breakage.
- Fatigue or overload fracture of pylons, adapters, keels, or knee axes (the hazard ISO 10328 is written to bound).
- Upper-limb device abandonment after poor control, weight, or cosmetic mismatch.
- Contact dermatitis, liner folliculitis, and (less often) metal allergy at the interface.
- Periprosthetic joint infection, aseptic loosening, and wear-debris osteolysis or adverse local tissue reaction in joint implants.
- Breast-implant rupture and capsular contracture.
- Prosthetic-valve thrombosis, endocarditis, and structural valve deterioration.
- Myoelectric electrode lift-off, control dropout, or battery exhaustion in powered limbs.
- Which of these failure modes and hazards hold for the sense of prosthesis this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- United States: 'prosthetic' is often a noun; Medicare K-levels (K0-K4) and HCPCS L-codes gate payment; prior authorization is routine.
- United Kingdom, Ireland, Australia, New Zealand: the clinician is a prosthetist; older NHS language is 'artificial limb' and 'limb fitting centre'.
- German-speaking social insurance: sharp Prothese vs Orthese split; external devices listed in the GKV Hilfsmittelverzeichnis (product group 24).
- Continental Europe commonly says 'endoprosthesis' for joint implants; U.S. practice says replacement or implant.
- South Asia: Jaipur-type vulcanized-rubber feet remain widely used; many programmes still build conventional (non-modular) sockets.
- ICRC and similar humanitarian services standardise polypropylene modular technology rather than carbon-fibre sport components.
- Myoelectric upper-limb provision is relatively high in parts of Western Europe and Japan; body-powered fittings remain common in U.S. workers' compensation and in most LMICs.
- Which of these regional variation hold for the sense of prosthesis this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Orthosis - The anatomical segment is still present; the device supports, aligns, or unloads it. Test: is the body part absent or only deficient in function?
- Powered exoskeleton - Worn over intact or paretic limbs to add power or constraint, not a substitute for a missing segment.
- Autologous reconstruction (flap, graft) - Living host tissue rather than a manufactured substitute; no serial device identifier or ISO 10328-type structural test.
- Allograft / transplant - Biological donor tissue, not a device; regulated as tissue or organ, not as a prosthesis under ISO 8549.
- Facial epithesis - Surface-applied, usually non-load-bearing restoration of facial soft tissue; overlaps craniofacial prosthesis but is distinguished from limb and joint devices by lacking a residual-limb or articular load path.
- Osseointegration abutment (percutaneous implant) - The pin is an implant that anchors an external limb; the distal worn device remains the prosthesis. Test: which part is inside bone versus coupled after the skin penetration?
- Wheelchair, crutch, or other mobility aid - Compensates locomotion without replacing the missing limb as a worn anatomical substitute.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of prosthesis this model covers, and on what evidence? provenance
Sources
- ISO 8549-1:2020 Prosthetics and orthotics - Vocabulary - Part 1: General terms for external limb prostheses and external orthoses - Core externally applied definition; the orthosis/prosthesis distinction used in P&O practice.
- ISO 10328:2016 Prosthetics - Structural testing of lower-limb prostheses - Requirements and test methods - Structural test levels tied to user body mass; component fracture as a governed failure mode.
- ISO 22523:2006 External limb prostheses and external orthoses - Requirements and test methods - Safety and performance requirements for external limb devices, including powered systems.
- WHO standards for prosthetics and orthotics (World Health Organization, 2017) - Service-delivery practice, low-resource fitting systems, and the global clinical use case.
- 21 CFR 890.3420 External limb prosthetic components; 21 CFR 890.3500 External assembled lower limb prosthesis (U.S. FDA) - U.S. device classification for external limb prostheses and related product-code family.
- Regulation (EU) 2017/745 on medical devices (European Union) - Placing on the market of prosthetic medical devices in the EEA, including implantable kinds.
- ISO 9999:2022 Assistive products - Classification and terminology - Assistive-product class 06 (orthoses and prostheses) as a naming scheme for external devices.
- Wikidata item Prosthesis (Q181802) - Cross-catalogue identifier for the general concept.
What the second pass must settle
- Does the registry intend prosthesis to include all internal replacement devices, including replacement valves and lenses, or does it assign some of these to neighbouring registered things?
- Where should the registry place hybrid devices that combine replacement, orthotic support and biological material?
- Which existing Vercy world models already own any of this concept, and should this registry entry link to them rather than introduce a separate publication?
- Which authoritative sources should establish subtype-specific performance criteria, inspection methods and intervention constraints?
- How should recipient-reported comfort and appearance outcomes, practitioner assessments and device measurements be reconciled when they disagree?