femur
Enable an agent to recognise a femur, describe its anatomical and mechanical state, and identify which observations or proposed actions require further evidence.
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.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a femur, describe its anatomical and mechanical state, and identify which observations or proposed actions require further evidence.
The femur is the paired long bone of the thigh in humans and many other vertebrates; in humans, it articulates proximally with the acetabulum of the pelvis and distally with the tibia and patella.
It can be Orient and identify a complete bone or fragment using a species-appropriate combination of landmarks.; Record geometric measurements with explicit landmarks, methods and uncertainty.; Locate observed changes within proximal, shaft or distal anatomy.; Compare observations across time or with the contralateral femur when identity and methods are compatible.; Assess whether available evidence supports an interpretation of development, loading or structural integrity.; Identify prerequisites for further imaging, specimen handling or specialist assessment without authorising clinical intervention..
Distinguishing features
Identify the vertebrate skeletal element occupying the proximal hindlimb between the pelvic articulation and the knee region; location alone is insufficient for an isolated fragment.
For a human femur, check for a rounded proximal head connected through a neck, trochanters, a shaft and paired distal condyles.
Distinguish a human femur from a humerus by the combined proximal trochanteric anatomy and distal condylar arrangement, rather than by its long-bone shape.
Distinguish a human femur from a tibia by its proximal head and neck rather than a tibial plateau, together with its distal anatomy.
Treat the femur as the bone itself: a thigh includes surrounding tissues, while a prosthetic femoral component is an implant.
Scope
+ Identification of a femur, its species context, laterality and anatomical orientation
+ Proximal end, shaft, distal end and their structural relationships
+ Bone geometry, cortical and trabecular organisation, and marrow cavity
+ Developmental stage, growth regions and skeletal maturity
+ Articulation, muscle attachment and load transmission
+ Observed integrity, remodelling and alterations of the bone
- The whole organism, its taxonomy or its population
- The thigh as a region containing muscles, vessels, nerves and other tissues
- The pelvis, tibia, patella and complete joint systems
- Disease entities and patient-level diagnosis or treatment plans
- Orthopaedic implants and surgical instruments as independently managed things
- Insect femora and other nonhomologous structures sharing the name
Characteristics
- Species attribution
- Identified organism or taxon; uncertain; unknown Landmarks, proportions and developmental interpretation depend on species.
- Laterality
- Left; right; indeterminate Prevents incorrect orientation, pairing and assignment to an individual.
- Represented anatomical extent
- Complete bone; proximal end; shaft; distal end; multiple fragments; indeterminate fragment Determines which identification tests and measurements are possible.
- Femoral length
- mm, with endpoints and measurement method Supports comparison only when the anatomical endpoints and completeness are known.
- Neck-shaft angle
- Degrees, with axis definitions and imaging or specimen method Describes proximal geometry relevant to alignment and loading.
- Femoral version
- Degrees, with proximal and distal reference axes and sign convention Records rotational geometry without confusing it with positioning during observation.
- Regional cortical thickness
- mm, with anatomical location and acquisition method A local measurement cannot represent the structural condition of the entire bone.
- Growth-region status
- Open; closing; fused; unobservable, recorded separately by region Separates developmental anatomy from mature anatomy and limits age inference.
- Structural integrity
- Observed intact; discontinuity; deformity; tissue loss; indeterminate, with location and evidence Supports assessment of the bone while keeping observation separate from diagnosis.
- Articulating relationships
- Identified pelvic, tibial and patellar counterparts, as applicable to species Places the bone within its joint system without treating the complete joint as part of the femur.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 19 findings · 29 questions.
Femoral identity and boundaries Establish which bone is represented and which anatomical sense of femur applies.
The name alone does not establish species, side, completeness or whether a similarly named structure is homologous.
Skeletal element identification
Recognise the proximal hindlimb bone from anatomical context or preserved morphology.
Femur identification basis
Record the landmark combination or articulated position supporting identification, with alternatives where preservation is insufficient.
- Which preserved landmarks or articulated relationships establish that this is a femur? definition
- What supports the species attribution, and could another skeletal element explain the observed fragment? boundary
Side and specimen extent
Establish anatomical orientation and distinguish the bone from associated material.
Laterality and completeness
Represent side, preserved regions and associated tissues or implants separately.
- Which landmarks establish left or right and anterior or posterior orientation? definition
- Which femoral regions are present, and which attached tissues or components belong to neighbouring models? boundary
Femoral regions and geometry Describe the shape and spatial organisation of the proximal end, shaft and distal end.
Femoral recognition and mechanical interpretation depend on regional geometry rather than generic bone dimensions.
Proximal femoral geometry
Describe the head, neck and trochanteric region where applicable to the species.
Head, neck and trochanter relationships
Record proximal landmarks and their orientation relative to the shaft without assuming human proportions.
- How are the femoral head centre, neck axis and shaft axis defined for this observation? measurement
- Which proximal landmarks are present and reliably identifiable for the attributed species and developmental stage? definition
Shaft and distal geometry
Describe shaft curvature, condylar geometry and proximal-to-distal orientation.
Length, bowing and version
Keep longitudinal dimensions, shaft curvature and rotational alignment distinct and tied to explicit reference axes.
- Which endpoints and planes define femoral length and shaft bowing? measurement
- Which distal reference axis and sign convention are used to measure femoral version? measurement
Femoral tissue and development Represent internal bone organisation and developmental state by anatomical region.
External shape alone cannot describe growth status or the regional tissue organisation relevant to femoral condition.
Regional bone organisation
Locate cortical bone, trabecular bone and the medullary cavity.
Cortex, trabeculae and cavity
Associate tissue observations with a defined femoral region and distinguish measured structure from inferred strength.
- Where and by what method were cortical thickness or trabecular features observed? measurement
- Does the evidence describe bone tissue, cavity contents or an inference about mechanical competence? boundary
Growth and maturation
Describe ossification and growth-region status without reducing development to a single assumed age.
Regional maturity evidence
Record visible developmental features separately for proximal and distal regions and relevant secondary centres.
- Which growth regions or ossification centres are visible, and what is their observed status? definition
- Which species-specific reference supports any age or maturity interpretation? provenance
Femoral articulation and loading Connect femoral surfaces and attachment sites to joint participation and mechanical function.
The femur's role depends on its pelvic and knee relationships, muscle forces and loading context.
Joint and attachment interfaces
Locate articular regions and attachment landmarks while preserving boundaries with surrounding tissues.
Articular and attachment map
Identify femoral contributions to joint surfaces and relevant muscle or ligament attachment sites.
- Which observed femoral surfaces articulate with which neighbouring skeletal elements? definition
- Which findings concern the femoral surface itself, and which concern cartilage, ligaments or muscles? boundary
Mechanical context
Interpret geometry in relation to posture, locomotion and applied forces.
Loading assumptions and limits
Make explicit the conditions behind mechanical interpretations and proposed uses of those interpretations.
- What posture, activity, joint constraints and force assumptions underlie the proposed loading interpretation? measurement
- What additional evidence is needed before this femur's geometry can inform a mechanical or intervention decision? action
Femoral condition and evidence Record regional alterations and determine what the observation method can support.
An apparent femoral defect may reflect biological change, specimen damage or imaging limitations, each with different implications.
Integrity and regional change
Locate discontinuity, deformity, remodelling, tissue loss and implant-associated changes.
Observed femoral alteration
Describe the location and morphology of an alteration separately from its cause or clinical classification.
- Which femoral region and surfaces are affected, and what alteration is directly observable? definition
- What evidence distinguishes biological change from post-removal damage or an observation artefact? provenance
Observation quality and comparison
Qualify femoral measurements and comparisons using acquisition, identity and positioning evidence.
Measurement comparability
Account for projection, calibration, anatomical coverage and specimen identity before comparing apparent femoral differences.
- Could positioning, magnification or incomplete anatomical coverage explain the apparent difference in femoral geometry? measurement
- What identity, laterality and acquisition evidence must be checked before comparing this observation with another femur or time point? 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.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The registry supplies no sense; this description emphasizes human anatomy. The femur is an anatomical structure, not an organism or taxon.
- In arthropod anatomy, femur also names a leg segment; that distinct sense is not covered here.
- Measurements are approximate recall values, not diagnostic limits; verify measurement protocols, reference populations and exact ontology identifiers before publication.
- Which of these check these first hold for the sense of femur this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Left femur
- Right femur
- Which of these kinds and varieties hold for the sense of femur this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- Terminologia Anatomica - Femur - Anatomical name in the terminology maintained by the Federative International Programme for Anatomical Terminology (FIPAT).
- Foundational Model of Anatomy (FMA) - FMA numerical identifier - Identifies an anatomical class; an individual bone and its laterality require additional representation.
- Which of these identifiers and schemes hold for the sense of femur this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- Terminologia Anatomica, maintained by FIPAT, standardizes human anatomical terminology for the femur and its named parts.
- Which of these standards and regulation hold for the sense of femur this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Transmits loads between the hip and knee during standing and movement.
- Provides attachment sites and leverage for muscles moving the hip and knee.
- Contains marrow and participates in bone remodeling and mineral storage.
- Provides anatomical landmarks for fracture fixation and hip or knee replacement.
- Used in skeletal anthropology to estimate stature from population-appropriate reference equations.
- Which of these real-world use hold for the sense of femur this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Adult human femoral length - Approximately 40-50; varies substantially with stature and population, and depends on measurement method - cm
- Adult human femoral neck-shaft angle - Approximately 120-135 - degrees
- Which of these typical measurements hold for the sense of femur this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Fractures can involve the proximal femur, shaft or distal femur.
- Femoral shaft fractures can cause substantial internal blood loss.
- Displaced femoral neck fractures can compromise blood supply to the femoral head, causing osteonecrosis.
- Fractures may develop nonunion or heal with malalignment.
- Osteoporosis can increase susceptibility to proximal femoral fractures after low-energy trauma.
- Which of these failure modes and hazards hold for the sense of femur this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Femoral dimensions and proportions vary within and among human populations; population averages do not reliably identify an individual's ancestry.
- Stature-estimation equations based on femoral length require reference populations and measurement methods appropriate to their intended application.
- Which of these regional variation hold for the sense of femur this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Humerus - The long bone of the upper arm, rather than the thigh.
- Tibia - The principal weight-bearing bone of the lower leg; it meets the femur at the knee.
- Patella - A sesamoid bone within the quadriceps tendon that articulates with the distal femur.
- Hip bone - A pelvic bone containing the acetabulum that receives the femoral head.
- Thigh - The body region containing the femur, muscles, vessels, nerves and other tissues.
- Femoral head - The proximal articular part of the femur, rather than the whole bone.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of femur this model covers, and on what evidence? provenance
What the second pass must settle
- Does vr.tr.femur intend the human femur specifically or the homologous vertebrate skeletal element across species?
- Which existing Vercy world model, if any, already owns this concept and should be linked instead of duplicated?
- Which anatomical authorities and measurement conventions should govern landmarks, neck-shaft angle and femoral version?
- Which species- and population-specific developmental references are appropriate, and what uncertainty accompanies maturity interpretation?
- Which intended use cases - anatomical recognition, clinical observation, comparative anatomy or specimen curation - determine the required evidence and action boundaries?