Study sets, textbooks, questions
Upgrade to remove ads
Week 7 LOs
Terms in this set (72)
· Explain the mechanism by which cartilage gets its nutrients and disposes of its wastes.
Water allows for the transport of nutrients from blood vessels and other sources (synovial fluid, subchondral bone) because normally cartilage is avascular
Function of articular cartilage?
-prevent direct contact of bones
What effects of aging have on articular cartilage
overall cartilage gets
water content decreases, fewer chondrocytes, collagen crosslinking increased
What muscles are used in the full 180 degrees of abduction of the arm at the GH joint?
first 15 degrees= supraspinatus
15-120 degrees= deltoid
120-180= serratus anterior and trapezius
what compartment, action, and innervation does extensor carpi ulnaris do?
-in the medial compartment
-extend wrist and do adduction (go from lateral epicondyle of humerus and insert at base of 5th metacarpal)
-innervated by deep branch of radial nerve and arterial supply is ulnar artery
What additional action do abductor pollicis longus, extensor pollicis longus, extensor polliscis breivs do?
all abduct the wrist and ALSO longus & brevis extend the thumb
Adduction= ulnar deviation
abduction= radial deviation
What is the innervation of abductor pollicis longus?
also flexes the wrist
Describe the flow and pathway of the radial artery as it travels distal to the snuffbox.
runs deep in the hand compared to the ulnar artery and will run between the thumb and the 2nd finger and give off the deep palmar arch-->this arch has metacarpal branches
vs. the superfical arch (from ulnar artery) has phalange branches
NOTE: there are anastamoses between the arches
What provides the compressive strength of bone?
calcium hydroxyapatite (inorganic crystalline structure)
Which bones are formed and describe the process of intramembranous ossification and endochondral ossificaiton
endochondral ossificaiton= long bones (humerus, femur), and short bones (carapl bones, tarsal bones)
-cartilaginous modesl-->ossification centers
-growth plates and primary and 2nd ossificaiton centers
intramembranous ossificaiton: flat bones (skull, clavicle)
-mesenchymal cells coalesce-->osteoblasts-->bone
Describe the process of intramembranous ossificaiton.
Process: have ossification centers with osteoblasts that secrete osteoid that traps osteoblasts that become osteoclasts and clusters of osteoblasts form small spicules of bone that will end up forming bone plates
If a child has osteoporosis, dental abnormalities and large fontanelles what condition do they have and what are the genetics?
AD condition with the Cbfa1/Runx2 gene that is a regulator of osteoblast differentiation so why affect intramembranous ossificaiton
What part of the epiphyseal plate (between epiphysis and metaphysis or primary or secondary ossification centers) is most likely to fracture?
hypertrophic zone because cells (chondrocytes) are less dense here
Describe the pathophys. of achondroplasia.
Achondroplasia/Dwarfism: AD condition
-grain of function mutation in the growth factor receptor 3 of fibroblasts that result in activation of them
this then results in inhibition of chondroblast differentiation at the epiphyseal plate
Describe how blood flow affects the healing of bone.
more blood flow (for examle in the femur) will result in faster healing or clearing of an infection
in comarison to the tibia which has way less blood flow
which type of mechanical force are bones worse at standing?
worse with shear stress (perpendicular to bone) but best with compression
so if force is coming from right side (hand turned toward bone) will have the split fragments more medial
What is the lineage and makrers you can test for between osteoblasts and osteoclasts?
Osteoblasts= mesenchymal stem cell and test for alkaline phosphatase
Osteoclasts= hematopoeitic cell and test for TRAP also test for carbonic anhydrase??-eats bone
If somone has a mutaiton in the carbonic anhydrase enzyme what disease might they get?
CA is made by osteoclasts that eat bone
What does: to osteoblasts and osteoclasts
-vit D: increase release of calcitonin form osteoblasts to inhibit osteoclasts
-PTH: activate osteoclasts-->lytic lesion
-bisphosphates: inhibit osteoclast
If the neck of the femor is crushed what arterial supply should we be conerned about
medial femoral circumflex artery
What movement do all 3 hip joint ligaments: prevent
All 3 ligaments prevent extension of the hip joint
Which direction is the femor most likely to disslocation?
posterior--9x more likely than posterior
What is a unique feature of the knee that makes it unstable?
: the femur and the tibia come together-->about 10 degrees in males and even higher in women becuase of wider pelvis
What does it mean if someone has:
Genu varus: "bowed-legged"-->decreased Q angle
Genu valgus: "knock-kneed"-->increased Q angle
Which direction do the menisci shift in the knee when it is extended vs. flexed?
Lateral and medial menisci shift anterior when knee is extended and then shift posterior when the knee is flexed
NOTE: these fibrocartilagenous structures that artiulate with the condlyles of the tibia and femur
Where will you find the knee cruciate ligaments in relation to the synovial membrane and the fibrous capsule?
What dispalcement do they prevent?
they are inside the fibrous capsule but outside the synovial membrane
PCL= prevents posterior displacement of the tibia on a fixed femur AND anterior displacement of the femur on a fixed tibia
ACL= prevents anterior displacement of the tibia on a fixed femur AND posterior displacement of the femur on a fixed tibia
NOTE: both ligaments are tight/tensed when the knee is in hyperextensin OR hyperflexion
Which motion does the lateral and medial collateral ligaments prevent?
Lateral collateral ligament limits adduction
Medial collateral ligament limits abduction
NOTE: our bones especially in early life, are in an equilibirum of resoprtion (destroy) and reformation
What is the difference between osteomalacia and osteoporosis?
What are the most common cause of each?
Osteomalacia= poor mineralization (decreased bone quality)-->vit D. deficiency
Osteoporosis= decrease bone quanitity (decrease in bone mass but normal bone mineralization)-->aging
Understand how transmitter action is terminated at the neuromuscular junction.
Acetylcholinesterase breaks down Ach (needs to unbind from receptor before it can be broken down)
Choline is taken back up into presynaptic terminall for re-synthesis of Ach
What is a common clinical physical exam finding with a hip osteoarthritis?
-trendelenburg sing (hip drop and the oppsoite side that drops is bad)
-restricted internal rotation of the hip
-weak hip abductors
What is the treatment plan for hip osteoarthritis?
weight loss and activity (PT)-->oral NSAIDs-->injection (steroids)-->surgery
When is it not indicated to do arthroscopy for operative treatment for knee osteoarthritis?
if somoeone has arthritis then don't do arthroscopy for knee
What is a complication of knee joint replacement>
about 15% of people will come away wiht persistent pain and dissastificaiton
What is the difference between contiguous osteomyelitis and hematogenous myelitis
what are some examples
Contiguous= when the tissue that surrounds bones becomes damaged in some way (soft tissues, surgical site, or trauma)-->examples diabetic neuropathic ulcers, pressure ulcers, open fractures, prosthetic joints, bite wounds
Hematogenous= from the blood (bacteremia)
What are the most common sites for hematogenous osteomyelitis in children vs. adults?
long bones in children
spine in adults
What is the pathophys of hematogenous osteomyelitis?
-inflammatory response from neutrophils
Pus-->increased intraosseous pressure-->impedes blood flow-->local ischemia-->bone necrosis
What is a main clinical sign that there is an infected bone?
sinus tract formation-->probing to bone through ulcer or sinus
What sort of physical exam should you do if you suspect osteomyelitis?
-look for sinus tract
-prob to bone through ulcers or sinus
-point tenderness over bone
-assess peripheral circulation
-assess for infection of ulcer and surrounding tissues
Distinguish between chronic contiguous osteomyelitis and acute hematogenous osteomyelitis. (treatments)
Acute: onset is within 2 weeks and use antibiotoics to treat (rarely use surgery)
-Examples: vertebral osteomyelitis and long bone osteomyelitis in children
Chronic: months after onset of symptoms. use surgery to treat (need to get rid of infected bone) followed by antibiotics
-Example: diabetic foot osteomyelitis
What lab markers would you expect to see in the case of osteomyelitis?
-elevated ESR (like in the 100s)
-elevated CRP (c-reactive protein)
-increase in WBC (or may be normal)
-common to see anemia of chronic disease
What sort of imaging is best to run for someone with suspected osteomyelitis?
MRI-->high sensitivty but not as specific because could trauma, pressure, Charcot arthropathy could mimic sings of infection
What do you need to do to confirm diagnosis of osteomyelitis?
Bone biopsy and during that can do debriedment of any dead bone
send this biopsy for gram stain, culture, and
What is the most likely bug to cause osteomyelitis?
In the case of osteomyelitis when would you optimize goals of care to be either cure or suppression?
Try to do suppression over cure when cure would hinder ones quality of life
Example: if need to amputate to cure
If someone comes in and has suspected osteomyelitis infection do you want to start them on empiric antibiotics right away?
NO-->fine to wait until you have the cultures to figure out what type of bug it is
don't need to do unless: associated significant soft tissue infection OR severe systemic illness
What is the presentation of septic arthritis?
children vs. adults?
-sudden onset of pain, swelling, restricted movement, could have signs of infection
-knee in children
-hip in adults
(vs. in osteomyelitis its long bones in children and spine in adults)
Often have history of:
injection drug use
Which category of bug is most common cause of septic arthritis?
bacterial (gram +,
fungal is much less common
bacterial could be from bacteremia from distant infection, local trauma, surgery,
What are some of the risk factors for septic arthritis?
-recent joint surgery
-IV drug abuse
When should you double check for gonococcal arthritis causing septic arthritis?
-more common in women
-pregnancy or menstruation
What are some distinctions between gonococcal reactive arthritis and septic arthritis?
Septic: usually involves one joint, the knees, can find gonococcal in the synovial fluid and blood, and can have skin lesions present over affected joint but won't have widespread rash
How do you go about diagnosing septic arthritis?
What would you expect to see?
don't waste anytime and want to drain the synovial fluid and send for culture and also run crystals:
Expect to see:
-blood culture + (in about 50% of time)
-yellow turbid fluid
-increase in ESR/CRP
When to send cultures for unusual organisms?
-Hx of TB
-Hx of trauma or animal bite
-live in an endemic area of fungal infections or lyme
-monoarthritis refractory to conventional therapy
what is the difference in treatment of osteomyelitis vs. septic arthritis?
Gram+ vs Gram-?
Septic arthritis you want to treat with Abx right away:
-gram += vancomycin, daptomycin, or linezolid
-gram -= ceftriazone
Osteomyelitis= don't need to treat with abx right away and should wait for culture
What nerve roots make up the lateral femoral cutaneous nerve and what region does this supply?
Roots from L2 and L3
Supply the "belt" region and dorsal lateral cutaneous thigh
If someone comes in and has lost sensation around their belt area what nerve is this?
lateral femoral cutaneous nerve (L2 and L3)
What are the nerve foots of the following nerves:
-superior gluteal: L4-S1
What nerve roots make up the lumbosacral trunk?`
L4 and L5
What nerves and roots make up the sciatic nerve?
common fibular (L4-S2)
If a muscle is attached to the illum what division (anterior or posterior) will innervate it usually?
what about ischium or pubis?
ilium= posterior division fibers
ischium or pubis= anterior division fibers
what division (anterior or posterior) does flexion and extension in the lower limb?
LEG rotates 180 degrees during development
Fascia lata (in the thight) and crural fascia in the leg divide the compartments in the thigh and
What are some of the anastomoses in the thigh between the external and internal iliac?
Which part of the thigh doesn't have collateral circulation and is dangerous if loses blood supply?
Head of femur doesn't have anastamoses and if the medial femoral circumflex artery gets crushed then dangerous to lose and get bone death
If someone is having trouble climbing up stairs and walking what muscle might be damaged? Innervation?
Iliopsoas (psoas major and iliacus) combine to form
this is the main flexor of the hip
Innervation= ventral rami of L1-L3 and femoral nerve (more iliacus)
What is the action of the quadratus lumborum?
elevate pelvis and abduct trunk
What nerves pass inferior and superior to the piriformis?
Where do they exit?
Superior gluteal nerve and artery pass superior to piriformis and exit the greater sciatic notch
Inferior gluteal nerve, pudendal nerve and sciatic nerve all pass inferior to the piriformis muscle at the greater sciatic notch
If someone is having trouble doing lateral rotation of the hip what muscles might be affected?
P-GOGO-Q (deep gluteal muscles)
Gemellus superior and inferior
Obturator internal and external
What muscles all do extension of the leg at the knee joint?
-vastus lateralis, intermedius, medialis
What action does rectus femoris do at the hip?
vs. extension of the leg at the knee joint
How is a good way to tell the difference between semitendinosus and semimembranosus (posterior thigh muscles) that extend the hip?
Semitendinosus= thick, round tendon that inserts on the tibia
Semimembranosus= thin, flat tendon that attaches to ischial tuberosity
Which tendon of muscle can be palpated when the knee is flexed at 90 degrees along the lateral side?
Sets with similar terms
Topnotch Musculoskeletal Anatomy
MedicaL Terminology Chapter 15
Chapter 15: Musculoskeletal System: Pathology
Chapter 6 The skeletal system,
Other sets by this creator
Week 9 LOs
Week 8 LOs
Week 6 LOs
Week 5 LOs