The skeletal system (systema skeletal in Nomina Anatomica) includes bones and cartilage. The bony skeleton includes bones only. The vertebral column is part of the skeletal system, and includes the intervertebral discs (fibrocartilage). Individual vertebrae are part of the bony skeleton.
SNOMED CT considers the skeletal system subdivision part of the entire bone (system). This may change if there are procedures on cartilaginous skeleton that involve skeletal system subdivisions. |
In ordinary usage, bone combines the meanings bone organ and bone tissue.
The 5 anatomical concepts related to bone are:
Bone (tissue) is part of entire bone (organ); entire bone (organ) is part of skeletal system subdivision (system); skeletal system subdivision (system) is part of entire bony skeleton (body structure); and entire bony skeleton (body structure) is part of skeletal system structure (body structure). We can use Entire bone (system) to define aggregate concepts that involve bones.
FSNs for spinal levels should not contain abbreviations. Correct example,
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Bone organs are composed primarily of bone tissue, but there are some non-ossified parts. In particular, periosteum is clearly a part of a bone organ, but is not ossified tissue.
Bone marrow is contained within the marrow cavity, but it is not part of the bone organ. The (empty) marrow cavity is part of the bone organ. The bone marrow structure (body structure) is not a subtype of Bone structure (body structure).
Clinically, marrow disorders are not usually considered bone disorders, nor are marrow procedures considered bone procedures.
For example,
To differentiate marrow, vessels, nerves, and periosteum from the actual hard tissue of bones, we differentiate structure of tibia from 12611008 |Bone structure of tibia (body structure)|. The bone marrow and other soft tissues of the tibia can then be categorized separately from the hard tissues. Bone marrow diseases are not considered musculoskeletal diseases, so bone marrow structures should not be placed in the bone (tissue) structure hierarchy.
ICD does not use the standard anatomical definition of long bone. For instance, Benign neoplasms of long bones are distinguished from benign neoplasms of short bones; the bones of the hand are considered short bones. The anatomical definition of long bone cites the proportional relationship between length and width (length >> width). It is clear that metacarpals, metatarsals, and phalanges are included in the anatomical definition of long bone.
The index finger is the first finger and second digit. Do not use second finger. |
In order to accommodate the differences between anatomical definitions and classifications, SNOMED CT has anatomical groupings that correspond to the ICD groupings. Scapula, humerus, radius, or ulna and long bone of thigh or lower leg are used as the sites for grouper concepts that match ICD definitions and groupings.
The sternum is considered a bone organ. The manubrium, body, and xiphoid are parts of the sternum, classed as zones in the FMA.
Even though teeth are supported by the maxillary or mandibular bone, they are not part of the 70925003 |Bone structure of maxilla (body structure)| or 91609006 |Bone structure of mandible (body structure)|. Teeth are part of the 4335006 |Upper jaw region structure (body structure)| and 48077000 |Lower jaw region structure (body structure)|.
In many diseases and procedures, reference is made to areas of the body that may ambiguously imply either a joint or a region surrounding the joint. Some common ones are:
| Joint vs. Joint Region | |
|---|---|
This concept is used to define diseases and procedures affecting bones in the shoulder region, i.e. proximal humerus, scapula, and clavicle. It is not a bone, but a bone structure, and is part of the shoulder region.
27949001 |Intertarsal joint structure (body structure)|; SYN: Tarsal joint: This structure is part of a group of bones forming the tarsus or tarsal joint (ankle). The 27162001 |Talocalcaneonavicular joint structure (body structure)| is the articulation between the talus (one of the seven bones of the ankle joint) and the other bones of the tarsus, and is what is meant by the rarely-used term talotarsal joint. The talocalcaneal joint is a synonym for the 127863007 |Subtalar joint structure (body structure)|. Dislocations of the subtalar joint usually involve the 127864001 |Structure of talonavicular joint (body structure)|. The subtalar and talonavicular joints constitute the talocalcaneonavicular joint.
The meaning of the words arm and leg may be misinterpreted.
In SNOMED CT,
The word limb appears in the FSN of the body structure, while the word extremity appears as a synonym. Therefore, when constructing an FSN for a new clinical finding concept, this precedent should be followed:
FSN: 61685007 |Lower limb structure (body structure)|
PT: Lower limb structure
Synonym: Lower extremity
Additional descriptions of leg and arm are permitted for concepts whose FSNs refer to lower limb and upper limb respectively.
External sources, such as WHO Classifications, may have conventions for interpreting the meaning of phrases that contain the words arm and leg. These sources may be referenced to help determine the meanings of International Classification of Diseases (ICD) terms when mapping or completing other actions. ICD terms may differ from common usage and will not necessarily match SNOMED CT concepts. |
The shoulder region is part of the upper limb, and the hip region is part of the lower limb. This follows the general pattern used in the Foundation Model of Anatomy (FMA).
The FMA defines:
The axilla is bound by the upper limb laterally and the thorax medially. It may be viewed as not strictly part of the upper limb or the thorax or it may be views as part of both. 91470000 |Axillary region structure (body structure)| is defined in SNOMED CT as being both an upper limb structure and a thoracic structure.
A muscle may be considered an entire functional unit, including attachments to the skeletal system, or merely the contractile part of this unit. In clinical use, muscle is the contractile part only. The FMA definition implies that tendons should be considered part of their corresponding muscles, rather than organs in their own right. SNOMED CT models |Tendon structure| as a subtype of |Skeletal muscle and/or tendon structure (body structure)|. Muscle and tendon are two separate anatomical entities.
For example,
61352006 |Structure of achilles tendon (body structure)| is not a 53451005 |Triceps surae muscle structure (body structure)| (gastrocnemius and/or soleus) muscle structure.
When modeling muscle categories according to their functions, assume they mean the function of the entire muscle, unless stated otherwise.
X disorder at Y level concepts from ICD-11, e.g. skin laceration of arm at wrist level (precedent are terms added from ICD-9) will not be added to the SNOMED International Release. |