Pathology and Abnormalities Flashcards
CHALLENGES TO IDENTIFYING PATHOLOGIES ON BONE
- No symptoms are identified on the living body- only evidence are bony lesions
- Only chronic/longstanding diseases affect bone, not all
- individuals w/ lesions: people who lived long enough to have disease affect the bone (were more healthy/strong)
- individuals w/ no lesions: people who may have died quickly from a disease
- Different diseases can have similar bony responses
- Postmortem/taphonomic changes may mimic disease => pseudopathology
RESPONSES BY BONE TISSUE TO PATHOLOGY
- Lytic lesions: removal of bone/necrosis
- Proliferation: addition of bone
- Combination of the two
FACTORS AFFECTING THE EXPRESSION OF DISEASE ON BONE
- Age
- Sex and gender
- Nutritional status
- General health & stress level
- Portal of entry (of pathogen)
- Exposure
- Environmental conditions
- Efficacy of treatment
STRATEGY: DIFFERENTIAL DIAGNOSIS
- *Describe lesions
- if lytic, proliferation, or combination
- precise location on body
- distribution on body*
- Other things to consider: geographic limits/locations of a particular pathogen
- The spread of lesions can often eliminate/bring into consideration certain diseases as possibilities
- Differential diagnosis: hypothetico-deductive reasoning
WHY IS CONSIDERATION OF ABNORMALITIES AND PATHOGENS SO IMPORTANT?
- Need to differentiate disease trauma from assailant trauma
- Can help in ID’ing individual
- Pathology knowledge can also differentiate peri- ante- and postmortem damage to the bone
- Can help distingusish normal variation of the skeleton from pathological damage.
CLASSES OF PATHOLOGY
- Congenital or developmental abnormalities
-genetically influenced disorders
-can include: -underdeveloped structures
-accessory structures
-fusion abnormalities
-absence of structures
Eg: Congentital dislocation, cleft palate - Metabolic abnormalities:
-reduced bone mass due to:
-inadequate bone production
-excessive remodelling
-mineralization
Eg: Rickets/osteomalacia: can lead to kyphosis, scoliosis, bowing, fractures=>inadequate mineralization of the bone, osteoporosis: change in bone quality and quantity - Inflammatory abnormalities:
-from infection of microorganisms
-responses can either be: -non-specific: periostitis: inflammation due to infection of the inner layer of periosteum
-osteomyletis: infection of bone by a particular pathogen
-specific: at a specfic area in the skeleton, for eg syphilis affects skull vault + tibia - Degenerative abnormalities:
-can be either: chronic- due to excessive wear and tear
-acute - result of trauma
eg: osteoarthiritis: eburnation, lipping, osteophyte formation due to extensive degeneration of articular cartilage - Endocrine abnormalities:
-resulting from abnormal hormonal production
eg: pituitary dwarfism leads to pronounced inhibition of longitudunal growth, hyperparathyroidism leads to cysts on interior surface of bones - Dental abnormalities:
Can result from dietary excesses or infection
-caries or cavities: destruction of tooth structure due to bacterial attack
-hypoplasias: abnormalities in enamel quality due to disturbances in development
-abcesses: pus cavities caused due to infection
-alveolar resorption/antemortem teeth loss (edentulism): wasting of bony socket in jaw due to loss of teeth
-calculus/tartar: hardened dental plaque - Circulatory or Hematological:
-due to disorders related to blood or blood-forming tissues
eg: anemia:
-cribra orbitalia: porous bone deposited in eye sockets
-porotic hyperostostis: diploe swelling, surface of cranial vault starts to appear porous as well - Neoplasia/tumor formation:
-abnormal growth in bone tissue
-Types: -malignant: progressive
-benign: localized
-primary (osteoma): arises in bones and joints
-metastasus (carcinoma): spread of tumors from soft tissue to bone
-quite rare archaeologically
ACTIVITY RELATED CHANGES IN BONES:
WAYS OF LOOKING FOR ACTIVITY
- Cross-sectional geometry
- Musculo-skeletal markers
- Degenerative changes/wear and tear
- Histology of trabecular bone
MUSCULOSKELETAL MARKERS
(MSMs)
Some terms:
- Entheses: Insertion site for tendons (muscles)
- Syndesmoses: Insertion site for ligaments (bones)
CONFOUNDING FACTORS WITH MSMs
aka
THESE ARE REALLY HARD TO READ
- Larger bones/joints = larger MSMs
- MSM relationship to muscle mass (unclear if linear or threshold)
- Preservation of MSMs
- Measuring MSMs, repeatability, as well as ordinal system of scoring
- MSM can’t tell us about specific activities: specific activities use several types of muscles, and diff activities can produce similar MSMs
ARTHRITIC OR DEGENERATIVE WEAR:
What do we examine?
Causes of osteoarthritis?
- Temporomandibular junction in cranium
- Post cranial bones
- Vertebral bones
- Age
- Weight
- Mechanical loading ( especially repetitve usage)
PROBLEMS WITH USING OA
- effect of age on OA, some areas seem to be more affected than others (such as the spine)
- multifactorial etiology: multiple causes aside from age and repetitive use:
-genetics
-BMI
-individual anatomical variation - force on bones depends upon anatomical variations (for example arthiritis in knees depends on tibia length)
-also depends on weight, genes, sex - OA is dependent on weight – heavier people have more OA in both weight bearing AND non-weight bearing joints (does more fat/leptin cause osteophyte formation)
- OA is dependent on activity as well: not just LEVEL of activity but also AGE OF ONSET
- Very poor indicator of SPECIFIC activities, only indicative of a general level of activity
- Need more consistent and standard reporting language
- Better engagement with clincal lit
*
SO WHAT IS OA GOOD FOR?
- Useful for indication of general level of activity
- Assymetry shows promise
- Animal studies have potential
- CS geometry + MSMs <=> OA’s
SKELETAL ANATOMIES
- Variation can be both environmental as well as genetic
- Can be adaptive => responding to particular environments (but not always straightforward!)
WHY IS IT IMPORTANT TO REMEMBER THINGS ABOUT SKELETAL ANOMALIES?
- Can be useful for distinguishing anomalies from trauma
- Can help to ID individuals
TYPES OF DIFFERENCES STUDIED
- Metric: Cranial or dental length/width measurements; looks at shape and size, continuous traits
- Non-metric: Discrete traits => present//absent
NON METRIC TRAITS
- Minor variations in ossification
- Correlates with soft tissue variation during development
CATEGORIES OF NONMETRIC VARIATIONS
- Foramen variation: trait expression depends on surrounding soft tissue (arteries, veins, neural)
- Variation in number of bones and teeth:
-extra ossicles within the sutures of the cranium
-supernumerary ossification centers
extra teeth - Articular facet variation: -extensions
-extra facets
-different position of joint surface: often activity related - Variation in tooth crown: -minor pits and fissures
-entire crown shape difference - Hyperostotic: Excesses: proliferations, bony spurs, bridges
- Hypostotic: Deficiencies (eg: metopic suture)
SEX RELATED DIFFERENCES IN HYPEROSTOTIC AND HYPOSTOTIC VARIATION
- Females: hypostotic traits
more towards the right
decrease with age - Males: hyperostotic traits
more towards the left
increase with age - Causes:
gendered activity differences
possibly genetic differences as well
MEANING OF NM TRAITS
- Genetic control, as well as environmental cues
- Population specific heritability of some traits
- Some are purely environmental: eg: squatting facets
HALTSTATT COLLECTION
- 700 skeletons, known identities + family relationships
- some traits under significant genetic control: metopic suture, certain ossicles, palatine torus, parietal foramena
- remember that heritability is population specific! so more research needs to be done with different pop.s
SOME FUN NON-METRIC TRAITS TO REMEMBER
- Metopic Suture
- Parietal Foramena
- Palatine Torus
- Os Japonicum
- Wormian bones
- Spondylolysis
- Squatting facets
- Enamel pearls
- Infraorbital suture
- Trochlear spur
- Pterionic bone
- Suture present b/w orbits, splits frontal bone into two
- Apertures present in parietal bones
- Bony protusion on palates
- Extra zygomatic bone
- Extra bones present along lamboidal suture
- Verterbral defect
- Facets formed on tibia due to excessive squatting
- Droplets of enamel present on teeth where they should not be present
- Suture present underneath eye orbits
- Bony spur present from upper portion of eye orbit
- Bone where frontal, parietal, lamboidal and sphenoid join together