Midterm 1 Flashcards
Long Bone
found in the limbs and act as levers for locomotion
an elongated diaphysis and two epiphyses, each of which encases a center for ossification
Short Bone
found in places of articulation - carpus and tarsus
all dimensions are relatively equal, generally signifying one center of ossification
Flat Bone
found in the skull, pelvic girdle, and scapula
it expands in two directions, with a broad surface for attachment of large muscle masses and protection of underlying structures
Sesamoid Bone
relieve tension within muscles and tendons - allowing for increased weight-bearing and tolerance by redistributing mechanical forces throughout a muscle or tendon
eg: patella and navicular bone
found withing tendons, where they change direction over prominences that would otherwise cause damage (relieving tensions and redistributing forces within muscle and tendons)
serve to displace tendon from the axis of the joint, increasing the leverage exerted by the muscle
they form synovial joints with major bones with which they are in contact
Irregular Bone
found in the vertebrae, hyoid
Splanchnic Bone
develop in soft organs remote from skeletal connection
eg: baculum - os penis, os cordis - oxen
Pneumatic Bone
Excavated to contain air spaces, such as the skull in the instance of paranasal sinuses, and the post-cranial skeleton of birds
important for bird respiration and flight
Diaphysis
comprise most of the length of the long bone (between the epiphysis)
Medullary cavity
contains bone marrow
Endosteum
inner surface of bone - growth, repair, remodelling
Periosteum
fibrous outer surface of bone - blood vessel, nerves, lymphatic vessels, nutrients to compact bone
attachments of ligaments and tendons
Bone on bone is very _____ for a horse
painful
Epiphysis
wider section of long bone
- spongy
- softer that diaphysis
- has articular cartilage
Articular cartilage
facilitates movement of connecting bones in joints
Metaphysis
inter region between diaphysis and epiphysis
remains cartilaginous until puberty then ossified and important for load bearing in joints
Short bones are found in the equine _______ (knee) and are often shaped as cubes and mainly spongy bone
carpus
_____ bones are made of spongy bone between two layers
flat
Sesamoid bones relieve ________ within muscles and tendons, allowing for increased weight-bearing and tolerance by redistributing mechanical forces throughout a _______ or tendon
tension; muscle
The shape of _________ bones is for function and cannot be categorized as long, short, flat, or sesamoid
irregular
Osteoporosis
decrease in bone mass and density
fracture easily
problems mostly related to nutrition
may lead to kidney issues
Osteopenia
low bone mineral density, but the density is not as low as osteoporosis, and bone is unlikely to fracture
Flared nostrils can be a sign that a horse is struggling to _______
breathe
Osteomalacia is aka ?
Big Head Disease
Fibrous Osteodystrophy
calcium , phosphorus and Vit D imbalance
aka: rubber jaw syndrome
Primary Hyperparathyroidism
elevated PTH
increased osteoclast activity
increased bone Ca resorption for bone
Secondary renal hyperparathyroidism
chronic renal failure with glomerular disease
increase PTH levels and resorb Ca from bone
Osteomalacia
aka big head or brain disease
under-mineralized newly formed bone
low Ca, high P diet with low Vit D is a cause
considered a type of osteodystrophy ‘Secondary Nutritional Hyperparathyroidism’
Osteonecrosis
‘avascular necrosis’
‘aseptic necrosis’
‘bone infractions’
vascular disturbance to the bone - decreased blood to bone
Bone Tumors
seen in 8% of older horses
and 17% of 30 yo horses
- benign tumors stay at local site – all benign tumors have metastatic potential
malignant tumors
spread locally and/or distant sites (metastatic disease)
Osteitis
inflammation of only the cortical bone
Osteomyelitis
inflammation of the bone and bone marrow
The black shown on an x-ray of osteonecrosis is ____ ____
dead bone
Pathogenesis bacteria adhere to bone or bone associated components of soft tissue in a horse with __________
osteomyelitis
A horse with osteomyelitis may have a ______ infection (most common) and hematogenous spread (bacteria seeded into bone from circulation
local
_______ bone is usually not infected with osteomyelitis
healthy
Traditional Treatments for osteomyelitis
1) Systemic Antibiotics - culture and sensitivity
2) Debride - necrotic tissue and avascular bone
3) Bone grafts - adds scaffolding for bone healing
How to fix osteomyelitis from implant failure:
remove the implant and clean everything really well
bones have ____ elasticity
some
__________ of the bones can cause damage
overuse
compression of the bone is very bad for _____ because it can crush growth plates
foals
Nutritional status, age, functional activities, and hormone levels are __________ factors of fracture healing
systemic
Severity of trauma, vasculature and nerve supply, bone loss, immobilization of the fracture, and contamination are _______ factors of fracture healing
local
3 phases of fracture healing
1- inflammatory
2- reparative
3- remodeling
inflammatory phase of bone healing
(2-3 weeks)
most important!
- messengers
- inflammatory cells
- angiogenesis and extracellular matrix
Reparative phase of bone healing
(2-12 months)
- most susceptible to mechanical forces (intra-fracture movement
- interfragmentary stability (periosteal and endosteal callus) - required for bone union and ossification of bone
Remodeling phase of bone healing
- mechanical forces remodel bone
- improper stability can lead to non union
- a break that heals correctly is even stronger than before
In general, _________ are ‘wear and tear injuries’ from repetitive use
fractures
Open fracture
bone penetrates through tissue and skin
bone is exposed to environment
** risk of infection
closed fracture
bone does not pierce skin
no bone exposure to the environment
partial fracture
incomplete break in the bone
complete fracture
complete bone break
bone separated in 2 sections
stable fracture
bone broken but not displaced (geometrically aligned)
displaced fracture
separation of the bone segments
In radiographs, black is ___, and _____ is everything else
air; white
Always take __ radiograph images to get a front and _____ angle
2; side
Transverse fracture
straight line across bone
aka slab fractures
spiral fracture
spiral formation across bone
greenstick fracture
bone bends but fracture does NOT separate bone into 2 segments
is a common risk in young horses or performance horses with little rest
torus fracture
‘buckling of the bone’
‘bulging’
is a less severe form of greenstick fracture
stress fracture
‘hairline’ fractutres
compression fractures
bones are crushed
oblique fractures
diagonal fracture across the bone
impact frature
bone segments ‘pushed’ into each other
segmental fracture
a section of bone is separated from other sections
avulsion fracture
bone fragment is separated form the bone by a tendon or ligament
aka chip fracture
comminuted fracture
bone is fractured in 3 or more segments
Options for fracture repair
1- stall rest
2- splint or cast
3- surgery: internal vs external fixation
4- euthanasia
It is always important to relieve ____ and anxiety
pain
Bandages and compression boots are used as __________ immobilizations for fractures
temporary
_____ casts can be used to treat laminitis
foot
_____ is used in a cast as a saw for removal
wire
A ____________ cast uses a pin to better stabilize things
transfixation
Cast complications
- pressure sores
- cartilage, soft tissue and ligament atrophy
- osteopenia
- tendon and ligament laxity
internal surgical fracture repair uses ___________ wire
cerclage
there are limits to external fixation in horses for bone fractures due to the animal’s _______
weight
