Patho: Musculoskeletal
T or F: the origin of joint stiffness is unknown in OA
TRUE
Are boys or girls affected by idiopathic congenital equinovarus more often?
boys
How might OA of the lower cervical spine present?
brachial neuralgia - aggravated by movement of the neck
How is calcium involved with the relaxation phase of muscle function?
calcium is pumped back into the sarcoplasmic reticulum by means of an active transport process
What is thought to be the primary target for the immune response in AS?
cartilage
What is pseudogout?
caused by the formation of calcium pyrophosphate dihydrate crystals
What is the proposed mechanism of adolescent scoliosis?
central nervous system issue involving the balance mechanism
What factor is directly correlated with hydroxyapatite crystal deposition in OA?
chondrocyte apoptosis
What are the fragments of articular cartilage digested by?
chondrocytes - digested by the cell's own lysosomal enzymes
What are the methods of reducing a fracture?
closed manipulation traction open reduction
What is positional equinovarus?
club foot in which the deformity can be passively corrected without surgical intervention
What is idiopathic congenital equinovarus?
clubfoot without a known etiology
What is a complete vs. incomplete fracture?
complete = all the way through incomplete = bone is still in one piece, not all the way through
What might cause in impacted fracture?
compressive axial energy or force directly to distal fragment
What does coupling consist of?
consists of migration of calcium ions to the myofilaments
What are tophi?
crystal deposition in subcutaneous tissues that are small, white nodules visible through the skin
What are some causes of tendinopathy?
crystal deposits postural misalignment hypermobility of a joint
What is involved with medial epiconylopathy or "golfer's elbow"?
degenerative process of the pronator teres, flexor carpi radialis and palmaris longus tendons at the medial humeral condyle
What initiates the second stage of muscle contraction?
depolarization of the T-tubules - to initiate coupling
What is the degree of deformity measured by in metatarsus adductus?
determined by the heel bisection line
When do the clinical manifestations of OA appear?
during the fifth or sixth decade of life
What is pain early in RA caused by? Late in RA?
early = pressure from swelling late = sclerosis of subchondral bone and new bone formation
What exactly hardens the woven bone callus?
enzymes increase the phosphate content and permit the phosphate to join with the calcium to be deposited as mineral to harden the callus
What is the first stage of muscle contraction?
excitation
What is nonunion?
failure of the bone ends to grow together
What is the etiology of flexible flatfoot deformity?
familial
What are some risk factors for DDH?
family history female gender metatarsus adductus torticollis oligohydramnios first pregnancy breech presentation
What is a subluxated hip in DDH?
hip maintains contact with the acetabulum but is not well seated within the hip joint
What must also be evaluated when metatarsus adductus is diagnosed?
hips for DDH
What is the rate of protein synthesis in the human body related to?
hormone levels (insulin) amino acid substrates overall nutritional status
What are the factors that influence gout?
hyperuricemia older age genetic predisposition excessive alcohol consumption obesity drugs lead toxicity
What results as a consequence of compromised circulation in RA?
hypoxia and metabolic acidosis - stimulates the release of hydrolytic enzymes from synovial cells into surrounding tissue
Where is pain generally localized with symptomatic tendinopathy?
localized over the involved tendon and movement in the affected joint is limited
What does the pannus in RA act like?
locally invasive tumor of the synovium
The loss of what is the primary defect in OA?
loss of articular cartilage (progressive)
What is the hallmark of the osteoarthritic process?
loss of proteoglycans from the articular cartilage
How is articular cartilage lost in OA?
lost through a cascade of cytokine and anabolic growth factor pathways
What are central joints most often affected by OA?
lower cervical spine, lumbosacral spine, shoulders an hips
What natural curvatures are lost as AS progresses?
lumbar lordosis is straightened and thoracic kyphosis is accentuated
Where can rheumatoid nodules atypically occur?
lungs (Caplan syndrome) heart spleen blood vessels
What is broken down as the joint space is infiltrated by matrix metalloproteinases in OA?
macromolecules of proteoglycans, glycosaminoglycans and collagen
Are males or females more likely to get AS?
males (10x more likely)
What is the peak age of onset in gout?
males 40-50 years old - later in females
What is cartilage destruction of RA mediated by?
matrix metalloproteinases that activate the synoviocytes to invade and attack the synovium and matrix
What are some results of a strong pull occurring too soon in a ligament or tendon tear?
may separate again or excessive amounts of scar tissue may render the tendon or ligament functionless
Where do greenstick fractures most commonly occur?
metaphysis or diaphysis of the tibia, radius and ulna
What is the most common foot deformity found in children?
metatarsus adductus
What type of injury will elicit the bone remodeling process?
microscopic bone injuries - fractures and surgical wounds heal the same as soft tissue injuries
What might be the cause of an occult fracture?
minor force or energy - a fracture that is hidden or not readily discernible
What type of crystal is deposited in connective tissues throughout the body in gout?
monosodium urate
When do most dysplasias occur in gestation and what are they the result of?
most often occur in 2nd and 3rd trimester - result of positioning factors
What is the prime mover of a muscle?
muscle agonist
What might subsequent pain of a fracture be caused by?
muscle spasm, overriding of the fracture segments or damage to adjacent soft tissues
What stimulates an intense inflammatory response right when a bone breaks?
necrotic bone tissue directly adjacent to the fracture site
What is the time frame of when hematoma, procallus and callus formation occur?
1. hematoma - within hours of a fracture 2. procallus - within days of a fracture 3. callus - within weeks 4. replacement and contour - within years
What are the bone stages of wound healing?
1. hematoma formation 2. procallus formation 3. callus formation 4. callus replacement 5. remodeling
What is joint effusion caused by in OA?
1. presence of osteophyte fragments in the synovial cavity 2. drainage of cysts from diseased subchondral bone 3. acute trauma to joint structures, resulting in hemorrhage and inflammatory exudation into the synovial cavity
What does the speed of bone healing depend upon?
1. severity of bone disruption 2. type and amount of bone tissue that must be replaced 3. blood supply and oxygen content at the site 4. presence of growth and thyroid hormones, insulin, vitamins and other nutrients 5. presence of systemic disease 6. effects of aging 7. effectiveness of treatment
What are some of the proposed mechanisms of OA?
1. subchondral bone changes 2. weightbearing stress 3. inflammatory mediators
What are the specific risk factors of OA?
1. trauma 2. long term mechanical stress 3. presence of inflammation 4. joint instability 5. neurologic disorders 6. congenital or acquired skeletal deformities 7. hematologic or endocrine disorders 8. drugs 9. obesity
How much is the need for ATP increased during activity?
100x
How much will maximal exercise increase oxygen uptake?
15-30 times over the resting state
How long is skeletal maturation delayed in children with LCP disease?
2 years
What is bone remodeling?
3 phase process in which existing bone is reabsorbed and new bone is laid down to replace it
At what age is LCP most common?
3-10 years old (in boys)
How long does the initial inflammatory phase of healing last?
3-4 days
How long does the entire process of bone remodeling take place?
3-4 months
How long does a healing tendon or ligament lack strength to withstand a strong pull?
4-5 weeks post injury
What percentage of OA of the hip might be related to DDH?
60%
At what degree will a lateral spine curvature result in decreased pulmonary function?
80 degrees
What do urate crystals react with specifically in the joint fluid?
neutrophils and monocytes
What factor stimulates apoptosis in chondrocytes in OA?
nitric oxide
Is OA characterized as inflammatory or non-inflammatory joint disease?
non-inflammatory
What might an improper reduction or immobilization of a fracture result in?
nonunion delayed union malunion
What temperature do muscles work best at?
normal body temperature
What is the treatment for asymptomatic flexible pes planus?
nothing!
When does collagen formation occur after a sprain or strain?
occurs 3-4 days after the injury
What is the time frame for joint stiffness in OA?
occurs with joint movement and dissipates after 30 minutes
What happens to the haversian systems in phase three of bone resorption?
old haversian systems are desteroyed and new haversian systems are formed
Where does the pathology of OA most commonly take place?
on load-bearing areas
Where in the bone are bone precursor cells located?
on the free surfaces of bones and along the vascular channels (especially the marrow cavities)
What is a common age-related disorder of synovial joints?
osteoarthritis
What occurs during callus replacement?
osteoblasts continue to replace the callus with lamellar bone or trabecular bone
What occurs during the callus formation of wound healing?
osteoblasts in the procallus form membranous or woven bone
What occurs during secondary bone formation (phase 3)?
osteoblasts line the walls of the resorption cavity lamellae in compact bone are laid down
What are fractures of the upper femur, upper humerus, vertebrae and pelvis most commonly associated with?
osteoporosis
What typically causes bursitis?
overuse or excessive pressure on a bursae
What is an indirect measure of energy expenditure?
oxygen consumption
What is the first symptom of OA?
pain and stiffness in one or more joints
Why are stress fractures painful?
painful because of accelerated remodeling - not because of trauma
What occurs during the remodeling stage of bone healing?
periosteal and endosteal surfaces of the bone are remodeled to the size and shape of the bone before injury
What is the formation phase of bone remodeling?
phase 3 - secondary bone formation
What occurs when a motor unit responds to a single nerve stimulus?
phasic contraction = also called a twitch
What occurs when the anaerobic threshold is reach and more oxygen is required
physiological changes occur - 1. increase in lactic acid concentrations 2. increase in oxygen consumption 3. heart rate 4. respiratory rate 5. muscle blood flow
What is a common cause of heel bursitis?
poorly fitting footwear
Who does osgood-schlatter most commonly occur in?
preadolescent and adolescents who participate in sports
At what age does acute bursitis most often occur?
primarily in the middles years and is often caused by trauma
What stage of healing do enzymes and growth factors aid in (like insulin, bone morphogenic protein and osteogenin)?
procallus formation
What is the position of a bone segment (post fracture) determined by?
pull of attached muscles, gravity, direction and magnitude of the force that caused the fracture
What is uric acid a breakdown product of?
purine nucleotides
What factor allows the muscles to activate the number of motor units to generate the desired force?
recruitment and repetitive discharge
What is the last step of muscle function?
relaxation
What is the fourth stage of LCP disease?
remodeling takes place and newly formed bone is organized into live spongy bone
What is an extremely common finding in conjunction with gout?
renal stones
What are fractures of healthy bones like the tibia, clavicle and lower humerus caused by?
result of trauma
What is nonstructural scoliosis?
results from a cause other than the spine itself, such as posture, leg length discrepancy or pain
In what disease might the joint space feel swollen and "boggy" with the sin having a ruddy or cyanotic hue?
rheumatoid arthritis
In what joint disease does the synovial membrane undergo hyperplastic thickening?
rheumatoid arthritis
What is a chronic, systemic inflammatory autoimmune disease distinguished by joint swelling, tenderness and destruction of synovial joints, leading to disability and premature death?
rheumatoid arthritis
What joint disease is potentially linked to a defect in telomere repair that may result in faster again of telomeres?
rheumatoid arthritis
What are the primary ion channels that control calcium release?
ryanodine receptors (RyRs) - intracellular receptors within skeletal muscle sarcoplasmic reticulum
What is a fracture in which a bone breaks into more than 2 pieces?
segmented
What is LCP disease?
self-limited disease of the hip that is produced by recurrent interruption of the blood supply to the femoral head
What is the primary function of a bursae?
separate, lubricate and cushion tendons, muscles and bony prominences
What are the common sites of bursitis?
shoulder (subacromial) elbow (olecranon) hip (greater trochanter) ischial knee heel
What is epicondylopathy related to?
smoking, obesity, work activities that involve forceful and repeptitive cyclic flexion and extension
What occurs in the initial stage of LCP disease?
soft tissues of the hip are swollen, edematous, and hyperemic with fluid - the joint space widens and the capsule bulges
What is a dislocatable hip in DDH?
sometimes located by can be dislocated easily - dislocated hip has no contact between the femoral head and the acetabulum
What are common causes of teratologic equinovarus?
spina bifida, diastrophic dwarfism
What are ligament tears known as?
sprains
What are joint mice?
spur-like bony projections that break off into the synovial cavity as seen in OA
What is converted anaerobically to sustain brief muscular activity?
stored glycogen and blood glucose
Which enzymes are markedly elevated in osteoarthritis?
stromelysin and matrix metalloproteinases
As the subchondral bone becomes unprotected in OA, what occurs?
subchondral bone becomes sclerotic (dense and hard)
What is an open reduction?
surgical procedure that exposes the fracture site and is brought into alignment under direct visualization
What is the first joint tissue to be affected in RA?
synovial membrane (lines the joint cavity)
What is inflammation of tendons known as?
tendinitis
What does the term tendinopathy include?
tendinitis, tendinosis and parateninitis
What is the painful degradation of collagen fibers known as?
tendinosis
What is repetitive discharge?
the adding of motor units within a muscle
What is oxygen debt?
the amount of oxygen needed to convert the buildup of lactic acid to glucose and replenish ATP and phosphocreatine stores
How does water affect the cartilage in OA?
the cartilage absorbs more water, due to disregulation of the proteoglycan pump
What is the third stage of LCP disease?
the dead formal head is replaced by a procallus (collapse and flattening of the femoral head is seen)
What provides osteoclasts with information about where to begin resorbing damaged bone in phase 1?
the distribution of apoptotic osteocytes - portion of the bone that dies
What is the second stage of LCP disease?
the entire epiphysis or anterior half of the epiphysis of the femoral head loses blood supply and the epiphyseal plate is softened
What does successful regeneration of skeletal muscle fibers depend upon?
the extent of the injury, preservation of vascular supply, availability of satellite cells and terminal axons for reinnervation
What is the cross-bridge theory?
the formation of the actin-myosin cross-bridges that releases ATP when attached
How is the foot positioned in clubfoot?
the heel is positioned varus and plantar flexed
What is the most common site for tophi?
the helix of the ear
Where is most uric acid eliminated from in the body?
the kidneys
Where is pain most commonly referred in LCP disease?
the knee, inner thigh and groin
What is a syndesmophyte?
the new enthesis of bone which forms on top of the old enthesis - give AS the classic "bamboo spine" appearance
What is phase 2 of bone remodeling?
the osteoclasts form a "cutting cone" which gradually resorbs bone, leaving behind and elongated cavity (resorption cavity)
What is an inflammasome?
the product of a macrophage trying to phagocytize MSU crystals in gout
Over time, what factor decreases in direct proportion to the severity of OA?
the quality and quantity of proteoglycans
What does the excitation stage of muscle contraction begin with?
the spread of an action potential from the nerve terminal to the neuromusclular junction
What is the total force developed in a muscle contraction?
the sum of the force generated by each motor unit
What is pannus?
the thick granulation tissue that synovium is converted into through the interaction of TNF-a and fibroblasts
What portion of the tibia is affected in osgood-schlatter disease?
the tubercle of the tibia
How do neutrophils and macrophages contribute to RA?
these phagocytes are drawn into the synovial membrane and ingest immune complexes - in doing so they release enzymes that degrade synovial tissue and articular cartilage
What is the function of troponin and tropomyosin in the stage of muscle contraction?
they are muscle proteins that bind with actin when the muscle is at rest
What is most tendon pathology caused by?
tissue degeneration rather than inflammation
What is initial pain of a fracture generally caused by?
trauma
What hormones does calcium affect in the coupling stage of muscle contraction?
troponin and topomyosin
What is the primary pathologic problem in AS?
uncontrolled bone formation
What is the key symptomatic feature of OA?
use-related joint pain relieved by rest
When and where is the pain of gout usually noticed?
usually noticed at night - 50% involve the MTP joint of the great toe
What are some extra-articular changes that can accompany AS?
uveitis fibrotic changes in lungs cardiomegaly aortic incompetence amyloidosis Achilles tendinitis
How are nerves and vessels affected in tendinopathies?
vascular and nerve ingrowth occurs - facilitating pain transmission (especially in Achilles and patellar tendinopathies)
When do bowing fractures usually occur?
when a longitudinal force is applied to bone
When does contraction of a muscle begin?
when calcium ions combine with troponin
When does a rupture of the Achilles tendon occur?
when forced dorsiflexion is applied to the foot when it is in plantar flexion
When is skin traction used?
when only a few pounds of pulling force are needed to realign the fragments of when the traction will be used for brief times only
When is maximum force generated in muscle contraction?
when the actin and myosin filaments have maximum interactions
When is ATP released in contraction?
when the actin-myosin complex is cross bridged with other actin-myosin complexes
When is closed manipulation used?
when the contour of the bone is in fair alignment and can be maintained well with immobilization
When does the relaxation phase begin?
when the sarcoplasmic reticulum absorbs the calcium molecules, removing them from interaction with troponin
What is muscle tetanus?
when the summation of contraction is reached where no further increase in force can be achieved
Where do ligament tears most commonly occur?
wrist, ankle, elbow and knee joints
Is movement of the joint normal in bursitis?
yes!!!
What is the highest incidence of fractures?
young males between 15-24 years old adults 65 years or older
What are the four-steps of muscle contraction?
1. excitation 2. coupling 3. contraction 4. relaxation
What are two complications of chronic RA?
1. formation of cysts in the articular cartilage or subchondral bone 2. rupture of a cyst or of the synovial joint itself
What is the electrical charge of the plasma membrane at rest?
-90mV - continually aintained across the sarcolemma
What are the three ways in which a buildup of uric acid can occur?
1. accelerated rate of purine synthesis with overproduction of uric acid 2. break down of purine nucleotides at an accelerated rate that also results in an overproduction of uric acid 3. deficiency of enzyme HGPRT
What are the three phases of bone remodeling?
1. activation 2. resorption 3. formation
What is the progression of articular cartilage loss in OA?
1. articular cartilage loses its glistening appearance - becomes yellow-gray 2. articular cartilage flakes off and deeper layers develop longitudinal fissures 3. cartilage becomes thin and may be absent over areas 4. subchondral bone becomes sclerotic
What are the three clinical stages of gout?
1. asymptomatic hyperuricemia 2. acute gouty arthritis 3. tophaceous gout
In which arthritic disease is back pain alleviated by movement and worsened by rest?
AS
What substances are necessary to fuel the complex processes of muscle contraction?
ATP and phosphocreatine
What might be the issue with a painful pes planus?
Achilles contracture or tarsal coalition
T or F: pain of OA is correlated with the radiological appearance of OA
FALSE!
Which enzyme is needed to break down uric acid?
HGPRT
What gene is highly associated with AS?
HLA-B27
What are the two gene defects that are commonly found among patients with RA?
HLA-DR4 and HLA-DP genes
Which inflammatory cytokines play a major role in cartilage degredation through the induction of nitric oxide synthase and nitric oxide?
IL-1 and TNF
What are the two immunoglobulin antibodies that are most commonly rheumatoid factors?
IgM and IgG
What is the most common sign of early AS?
LBP and stiffness
What might mimic sciatic pain?
OA of the lumbosacral spine
What is the method used for passively correcting idiopathic conginital equinovarus?
Ponseti technique - use of serial casting and then bracing until age three
What is activated in RA in order to promote osteoclast formation, causing bony erosion?
RANKL
What are bone remodeling units made up of?
bone precursor cells that differentiate into osteoclasts and osteoblasts
Who are incomplete fractures more common in?
bones of growing children
What is a pathological fracture?
a break at the site of a preexisting abnormality - such as a tumor
What is a fracture?
a break in the continuity of a bone
What is a torus fracture?
a buckle fracture in which the cortex buckles but does not break
What is structural scoliosis?
a curvature of the spine associated with vertebral rotation
What is a type of stress fracture that is a caused by abnormal stress or torque applied to a bone with normal ability to recover?
a fatigue fracture
What is a transchondral fracture?
a fracture that consists of fragmentation and separation of a portion of the articular cartilage that covers the end of a bone at a joint
What is a fragility fracture?
a fracture that results from a low-level trauma (one that would not normally cause a fracture) as seen in osteoporosis
What occurs during skeletal traction?
a pin or wire is drilled through the bone below the fracture site and a traction bow, rope and weights are attached to the pin or wire to apply tension and provide the pulling force needed to overcome the muscle spasm
What is aggrecan?
a proteoglycan that forms a major part of the extracellular matrix of cartilage and helps maintain its stability - possibly a causative agent for AS
What is a tear in a tendon known as?
a strain
What is a delayed union?
a union that does not occur until 8-9 months after a fracture
What is an avulsion a result of?
abnormal stress on the ligament or tendon - commonly seen in young athletes - sprinters, hurdlers and runners
What are fractures of the hands and feet usually caused by?
accidents in the workplace
What is positive muscle work?
accomplished during muscle shortening - the energy is released to exert force or lift a weight
What are the filaments that aid in muscle contraction?
actin (thin filament) and myosin (thick filament)
What is phase 1 of the bone remodeling cycle?
activation - occurs when a stimulus activates programmed cell death (apoptosis)
Who are transchondral fractures mostly prevalent in?
adolescents
When is the pain of osgood-schlatter most severe?
after physical activity that involves vigorous quadriceps contraction
When might calcium be deposited in the tendon origin area?
after repeated bouts of inflammation from tendonitis
What is the pain of OA aggravated and alleviated by?
aggravated by movement alleviated by rest
Where are trabeculae formed after a bone fracture?
along lines of stress - where unnecessary bone callus is resorbed
What are rheumatoid factors?
altered antibodies that become autoantibodies - antibodies that attack host tissues
What is a chronic inflammatory joint disease characterized by stiffening and fusion of the spine and SI joints?
ankylosing spondylitis
Which tendon is affected in osgood-schlatter disease?
anterior patellar tendon
What is OA caused by?
any condition that damages cartilage directly
What amino acid is modified to contribute to the pathogenesis of RA?
arginine --> citrulline
What is a proposed mechanism for the joint pain associated with RA?
articular distension and stretching of the fibrous joint capsule (with abundant nerve supply) fibrous shrinking so that movement is painful in any direction
What is a complete separation of a tendon or ligament from its bony attachment?
avulsion
Where does enzymatic destruction of articular cartilage begin?
begins in the matrix with the destruction of proteoglycans and collagen fibers
How is blood flow to a fracture site affected days after a fracture?
blood flow is increased within 48 hours of an injury
What occurs as synovial inflammation progresses to involve blood vessels and small venules in RA?
blood vessels and venules become occluded by the hypertrophied endolthelial cells, fibrin, platelets and inflammatory cells which decrease vascular flow to the synovial tissue
What ultimately forces the muscle to reduce activity?
fatigue and weakness due to the inability to respond to the need for ATP and the subsequent buildup of lactic acid
What are some other issues that RA might cause?
fever, malaise, rash, lymph node or spleen enlargement, Raynaud phenomenon
What is a procallus composed of?
fibroblasts, capillary buds and osteoblasts
What cartilage is primary involved in AS?
fibrocartilage in cartilaginous joints (vertebrae)
What are the joints most commonly affected by RA?
fingers, feet, wrists, elbows, ankles and knees
When will hematoma formation occur in the stages of wound healing?
first if vessels have been damaged causing hemorrhage
What is pes planus?
flat feet - generally benign
What type of contractures are common in RA?
flexion contractures
Where is calcium transported to and from when a muscle is in the contraction phase?
from the sarcoplasmic reticulum to the myofibril
What are some environmental factors that influence the development of RA?
geographic area of birth length of breast-feeding socioeconomic status smoking
What is a syndrome caused by an inflammatory response to uric acid production?
gout
What components surround soft tissue and cartilage when a ligament or tendon in torn?
granulation tissue with macrophages, fibroblasts and capillary buds
What type of fracture occurs when the outer surface is disrupted, but the inner surface remains intact?
greenstick fracture
What are the most often injured tendons in the body?
hands, feet, knee, upper arm, thigh, ankle and heel
What are peripheral joints most commonly involved in OA?
hands, wrists, knees and feet
What is a malunion?
healing of a bone in a nonanatomic position
How is energy expenditure directly measured?
heat production - heat is released whenever work is accomplished
What are some treatments for delayed union and non union?
implantable or external electric current devices, electromagnetic field generations, low density ultrasound to stimulate bone formation
When might a false joint or pseudarthrosis be visible?
in a nonunion
When might a spontaneous tendon rupture occur?
in an individual receiving local corticosteroid injections, fluoroquinolones and in personds with rheumatoid arthritis or SLE
Where are rheumatoid nodules most commonly found?
in subcutaneous tissue over the extensor surfaces of elbows and fingers
Where do the earliest pathologic changes occur in scoliosis?
in the muscles, ligaments and other soft tissues that become shortened
How is idiopathic scoliosis classified?
infantile, juvenile or adolescent - depending on the child's age at the time of onset
What is bursitis?
inflammation of bursal sacs
What is epicondylitis?
inflammation of the tendon where it attaches to a bone (at the origin)
What is the first thing that happens after a tendon or ligament is torn?
inflammatory exudate develops between the torn ends
What are the inflammatory components that are released in response to bone necrosis after a fracture?
inflammatory leukocytes mast cells TF-B PDGF prostaglandins
What does the rapid depolarization of the membrane initiate in muscle fiber contraction?
initiates an electrical impulse in the muscle fiber membrane called the muscle fiber action potential
How does the onset of RA generally begin?
insidiously - with fever, fatigue, weakness, anorexia and weight loss
What are fragility fractures of osteoporosis or osteomalacia known as?
insufficiency fractures
What are the immunoregulatory cytokines that contribute to joint damage in RA?
interleukins B cells matrix metalloproteinases
What is believed to cause metatarsus adductus?
intrauterine positioning
What is isotonic contraction?
involves the lengthening or shortening of a muscle
What type of contraction occurs when a muscle maintains constant length as tension is increased?
isometric contraction
What is difficulty in initiating joint movement, immobility or a loss of range of motion?
joint stiffness
What are Heberden and Bouchard nodes?
joint swelling of OA in the fingers
When does primary AS usually develop?
late adolescence or young adulthood
What is degeneration or irritation of the extensor carpi radialis brevis tendon?
lateral epicondylitis
Which hip is most commonly affected in DDH?
left hip
What is Galeazzi sign?
limb length discrepancy seen in DDH
What are the ways in which fractures are classified along a fracture line?
linear fracture oblique fracture spiral fracture transverse fracture
What is osteoarthritis characterized by?
local areas of less and damage of articular cartilage, new bone formation of joint margins (osteophytosis), subchondral bone changes, variable degrees of mild synovitis, thickening of the joint capsule