General Concepts - Overview Flashcards
function of osteocytes
communicate with each other, sensitive to mechanical stress and help stimulate bone remodeling
list the 4 reasons we stabilize fractures
To reduce pain
To facilitate healing
To improve function
To enable early mobilization
what is contained in the endosteum of a bone?
bone lining cells (that have the capacity to differentiate into osteoblasts)
mature osteoblasts
examples of fibrocartilage in the body?
- intervertebral disks
2. menisci
Lateral force to the knee can cause O’Donoghues unhappy triad, which has what ligaments damaged? (3)
- MCL
- ACL
- medial meniscus
what is an isogenous group in cartilage? what is it indicative of?
two or more cells in a lacuna (result of division)
indicative of growing cartilage (interstitial growth)
injured myocytes secrete ________, and ________ arrive within an hour and phagocytose necrosis debris. The __________ release: (3) ______, ______, _______
cytokines, neutrophils, neutrophils,
IL1, IL8, TNF-alpha
in imaging, you see a joint that has: Marginal erosions Overhanging edges Sclerotic borders Soft tissue whiteness
what is this most likely?
gout
depletion of _____ and addition of _____ causes rigor mortis in skeletal muscles
ATP, Ca++
An experimental drug designed to read through premature stop codons
ataluren
the ventral rami of limbs form plexuses…. what does this mean for peripheral nerves?
peripheral nerves are derived from multiple spinal levels! good for injury
mechanism of injury for a meniscal tear:
twisting of knee while weight bearing
joint between vertebral bodies is called:
joint between articular processes (facet joint) is called:
symphysis
zygaphophyseal joint (synovial)
what is micromelia and what causes it?
partial absence of a limb
FGF loss in AER (apical ectodermal ridge) later in limb development (after stylopod)
When knee extended, put valgus and varus stresses on the knee, see if there is movement of the tibia against the femur.
Repeat when knee at 20-30 degrees.
what is this called? what does a positive one indicate?
the Valgus stress test
positive - collateral ligament injury
squamous cells that cover the inside and outer surfaces of bone. a signal to remodel the bone can trigger there to become active and convert into osteoblasts:
bone lining cells
what are canaliculi? why are they important?
paths for the processes of osteocytes to make gap junctions with other cells and exchange nutrients and signal
organic bone matrix gives bone what physical property?
makes it tough
RESIST FRACTURE
Valgus opening at 30 degrees is diagnostic for isolated _____ injuries
MCL
what 3 laxity exams can be performed to look for an ACL injury. which of these is the least specific/sensitive?
Anterior Drawer
Lachman test
Pivot shift test
Anterior drawer is not as sensitive or specific.
_________ is secreted by osteoblasts and binds to RANKL, not allowing for its union with RANK.
what does this do to bone resorption?
osteoprotegerin (OPG)
decreases bone resorption
_________ muscle contractions are more likely to cause injury
eccentric
special fracture classification for fractures in skeletally immature patients when it involves the physis
the Salter-Harris classification
Sensory loss across several dermatomes is indicative of a more _______ problem (the _______ or beyond)
distal
plexus or beyond
calcitonin _______ osteoclast activity
TRH ________ osteoclast activity
decreases
increases
_______healing – early mobilization, in _________, they need to be immobilized.
muscle, tendon
what is the ATP synthesis mechanism for strength training actions?
endurance training?
creatine phosphate
aerobic (mitochondrial) respiration
what are the three phases in secondary fracture healing?
- reparative
- restorative
- remodeling
idiopathic avascular necrosis in growing kids. involves the growing femoral epiphysis
see smaller, white, flat femoral head
Legg-calve-perthes disease
Radiograph findings with RA: (2)
- concentric (even) joint space loss
- erosions (mouse and cheese)
NO osteophytes
what is phocomelia and what causes it?
loss of internal limb structures (like micromelia - FGF loss in AER), but without disrupting the auto pod
HOX distribution error
excessive force from the rectus femoris muscle —-> _______ evulsion fracture
AIIS
all deep back muscles are innervated by:
dorsal rami of spinal nerves
where are chrondroblasts found in cartilage?
inside layer of the perichondrium, facing the cartilage
what is amelia and what causes it?
complete absence of limb
FGF loss in AER early in development (at stylopod)
excessive force from the __________ muscle —-> less trochanter evulsion fracture
iliopsoas
what can you see on a radiograph of osteoarthritis
Effectively no joint space (bone on bone)
Can also sometimes see bony enlargements
Bony sclerosis
Malalignment
a young male presents with:
Hypertrophied calves
Stand on toes
Exaggerated lumbar lordosis
Gower’s maneuver
what is it?
Mostly male Hypertrophied calves Stand on toes Exaggerated lumbar lordosis Gower’s maneuver
most common locations for osteoarthritis
Hands, hips, knees, base of cervical spine, big toes.
imaging modality used for radiographically occult fractures
MRI
strength training increases what part of the composition of muscles?
endurance training?
strength = sarcomeres, muscle diameter
endurance = angiogenesis, mitochondria
what are the healing steps of muscle?
inflammatory (destruction), muscle fiber regeneration (repair), collagen synthesis (remodeling)
ligament between the spinous process bodies and apices, relatively:
interspinous ligaments, supraspinous ligaments
examples of hyaline cartilage in the body?
- costal cartilages
- articular cartilage
- upper airways
the A band has the ______ filaments and the I band has the _____ filaments.
thick, thin
describe the histo of a tendon:
dense, regular T1 collagen, arranged in parallel to the direction of the pull
appositional growth of cartilage: ____________ secrete ECM
when chondroblasts secrete ECM
name the muscles in the erector spinae group:
what is they chief function? secondary?
chief function: extension of back
secondary: lateral rotation
spinalis
longissimus
iliocostalis
spine curvatures:
convex anteriorly: __________
concave anteriorly: ________
convex anteriorly: lordosis
concave anteriorly: kyphosis
what is adactyly? what causes it?
absence of digits
later loss of FGF in AER (apical ectodermal ridge)
in an IV drug user that has bacterial osteomyelitis, what is the most likely organism?
E. Clo, pseudomonas, klebsiella
what are the histological markers of most muscular dystrophies?
- different muscle fiber sizes
- fibrosis
- central nuclei (regeneration)
- degenerating and regenerating fibers (lot’s of nuclei)
broad yellow ligament extending between laminae, making the posterior wall of the vertebral column:
ligamentum flavum
Radiograph findings with osteoarthritis: (4)
- joint space loss (not even)
- osteophytes
- subchondral sclerosis (white)
- cysts
Marked laxity of the knee in extension with varus/valgus stress indicates
A knee injury involving both a collateral and cruciate injury
estrogen ________ osteoclast activity
decreases
what types of cartilage do not have perichondrium?
articular cartilage (type of hyaline)
fibrocartilage
How would you tell the difference between a sprain/strain?
joint instability (_________), ________ is more likely to have weakness.
sprain
strain
Gower’s maneuver is a sign of:
Duchenne’s MD
The perimysium is the CT covering in the center of the muscle between the __________
The endomysium is the CT covering between the muscle fibers, in the center of the fascicle
fascicles
muscle fibers (cells)
bilateral symmetric involvement of SI joint arthritis makes you think:
ankylosing spondylitis
in ligament healing… in the phase 3 of remodeling, the ratio of ___________ to _____________ increases
type 1 collagen to type 3 collagen
strains are _______ damage and sprains are _______ damage
muscle, ligament
ONLY ligament that runs the length of the spinal cord:
name:
where is it:
anterior longitudinal ligament
anterior to the body
injury to the ___________ ligament during ankle sprain could avulse the lateral malleolus of the fibula
anterior talofibular ligament
Many forms of MD are due to problems around the _________ membrane
sarcolemmal
2 parts of ECM of cartilage that make it resistant to compression and tearing:
aggrecan aggregate
type 2 collagen
what do the dorsal rami innervate? (3)
- deep back muscles
- back skin
- zygapophysial joints (synovial joints in back vertebrae)
in a person with sickle cell that has bacterial osteomyelitis, what is the most likely organism?
salmonella
what is the exception to the “X-ray first” theory of fracture imaging?
CT is used as the first line for spine fractures
bilateral asymmetric involvement of SI joint arthritis makes you think:
psoriatic arthritis or reactive arthritis
after the neutrophils come and release factors, ________ arrive and phagocytose additional necrotic debris. What do they release? (4) What does this activate?
macrophages
IL6, IGF, PDGF, TGF-b
satellite cells
a DXA T-score of -_____ or below is osteoporosis
-2.5
what is the exact location of “E-C coupling” for motor movement?
the t-tubule, sarcoplasmic reticulum channel articulation
Treatment for: ________ injury – prolonged immobilization (4-6 weeks)
· Complete tear/avulsion – __________, followed by immobilization
tendon, surgery
name the transversospinal muscles:
innervation function (unilateral contraction/bilateral)
Names: semispinalis, multifidus, rotatores
Innervation: dorsal rami spinal nerves
Unilateral contraction = CONTRALATERAL rotation
Bilateral = extensors
in a neonate that has bacterial osteomyelitis, what is the most likely organism?
H. influenzae
fracture healing type that needs:
Anatomic reduction, rigid fixation, direct bone formation
primary fracture healing
intramembranous ossification
splenius muscle function:
innervation:
extension of head and neck, ipsilateral rotation and bending
dorsal rami (it is a deep back muscle)
_______ are responsible for the differences in cutaneous nerve maps and dermatome maps
plexuses
the inorganic component of bone matrix is composed of _____________.
what strength does this confer for bone?
hydroxyapatite
stiffens, RESISTS BEND/COMPRESSION
the most accurate physical examination maneuver to determine an intact ACL is
the Lachman test
a dermatome is an area of skin supplied by a specific ____________
spinal level, NOT a specific peripheral nerve (think about the plexus)
Pain with forced flexion and rotation of the knee which may cause not only discomfort, but also a pop or click followed by pain. What test is this and what is the likely diagnosis if it is positive?
McMurray’s test
meniscal tear
critical period of limb development: weeks __-__
what is it called if there is a problem in the critical period?
4-8
malformation
what is the substrate use for muscle fibers in high intensity, short duration exercises?
low intensity long duration?
carbohydrates
fat
the _________ component of bone matrix is laid down first. What is it composed of?
Newly laid down matrix that has not been calcified: ________
organic, type 1 collagen
osteoid
History of sudden onset of force applied to outside or inside of knee with foot fixed to ground…
what ligament sprain could this be?
a collateral knee ligament
if you think a patient has a bone neoplasm and have a feeling it is osteoid osteoma, what imaging do you need?
CT
what type of gene inheritance is Duchenne’s muscular dystrophy? What is the gene?
X-linked recessive
short arm of X chromosome, Xp21
what is the most common organism of bacterial osteomyelitis?
s. aureus
interstitial growth of cartilage: ___________ secrete ECM
chondrocytes
sensory loss along the length of a single dermatome is indicative of a more _________ problem
proximal
in the intervertebral disks:
________________ = outer fibrocartilaginous ring imparts structural integrity
________________ = inner gelatinous core (notochord remnant) imparts malleability
annulus fibrosis
nucleus pulposus
Describe the proposed explanation for a higher incidence of ACL injury in female athletes
- decreased muscular strength
- less NMJ control
- Body movement mechanics
which types of muscle have sarcomeres?
skeletal and cardiac
tendon and ligament healing steps:
- inflammatory
- Reparative
- Remodeling
what is the general matrix of cartilage?
type 2 collagen and aggrecan aggregate
examples of elastic cartilage in the body?
- pinna of ear
2. epiglottis
fracture healing type that needs:
Acceptable reduction, micro-motion helpful, cartilage then bone formation
secondary fracture healing
endochondral ossification
excessive force from the sartorius muscle —-> _______ evulsion fracture
ASIS
________ detect the mechanical stress on a bone…causing an increase of _______ into the cell. This signal is then communicated to other cells through gap junctions and there is a proliferation of ____________
osteocytes
calcium
osteoblasts
the presence of intra-capsular floating fat in a joint cavity is called:
what are you concerned of with this?
lipohemarthrosis
fracture
blood supply to vertebral column:
branches off aorta
excessive force from the hamstring muscles —-> _______ evulsion fracture
ischial tiberosity
