8c. MSK pathologies Flashcards
what is the function of a joint
controlled movement and for stability
what constitutes as a synovial joint
articular cartilage over bone
synovial lined joint capsule with synovial fluid
what do ligaments connect
bone to bone
what do tendons connect
muscle to bones
what is acute trauma
bone cartilage and soft tissues (tendon/ligament/muscle) involved
what is chronic trauma
wear and tear
eg OA (bone, articular cartilage) or rotator cuff (tendon)
what joint is critical space for rotator cuff injuries
joint between acromion and HOH
what is the rotator cuff muscles
tendons that surround the shoulder joint
what are the 4 rotator cuff muscles
supraspinatus, infraspinatus, teres minor, subscapularis
what causes rotator cuff tears
repetitive overhead activities with arms up
what is rotator cuff tear
progressive degeneration of the supraspinatus tendon which is worn down or torn in sub acromial space
what is chronic trauma of the rotator cuff
reduced sub acromial space due to osteophytes
Space between head of humerus and acromion is gone - very little space for supraspinatus tendon to attach on HOH, bits that go through will get worn out by osteophytes caused by degenerative joint
what happens to the torn tendon and muscle when there is a chronic rotator cuff trauma
Worn away and snapped so muscle retracts and muscle undergoes fatty degeneration and this increases over time
what movement is difficult when there is a chronic rotator cuff trauma
Difficult to abduct arm overhead without supraspinatus
if a fracture goes through the joint surface what can happen
degenerative disease
what is done to shoulder dislocations before imaging
it is reduced
what are 3 scenarios in which shoulder dislocations are imaged
complex injury
post reduction to look for defect or fracture such as hill sach defect in HOH
planning corrective surgery
what is considered as a complex fracture dislocation
chunk of bone pulled off
If muscle is attached to bone fragment and it retracts that bit of bone will never heal as the muscles will pull it apart
what can happen if you dont oppose a glenoid fracture
can end up with OA
why can hill sach occur in head of humerus in shoulder dislocations
in people with chronic shoulder dislocations each time the shoulder is dislocated it has chipped away at some of the HOH bone so gets hill sachs
what 2 structures is the coronal section good for looking at
menisci and cruciate ligaments
how is menisci tears related to blood supply and healing
There is only blood supply to outer 25-30% of meniscus itself, if its in the center of the menisci it wont heal, need to chop it out rather than have it become loose body in joint
what happens when there is a full/partial tear in the cruciate ligament rupture and what is seen on imaging
area will be edematous and thick so will be bright on T2 MRI
what is a haemarthrosis
what are the layers and why
Fracture complex of tibia and blood from bone marrow of tibia has leaked into joint and there is fat anterior to the joint
Fat is lighter than blood so sits on top of blood in joint
what is the danger with haemarthrosis
Danger is that fat can get into veins and get to lungs causing fat emboli
in a knee dislocation what is a worry
Worried about integrity of the structures behind the knee
what are the structures behind the knee
Popliteal artery, vein and tibial and peroneal nerves
what can happen to the structures behind the knee in a posterior knee dislocation
Tibia displaced posteriorly and can press on artery behind it and could get ischemia of muscles below site of obstruction which is worse situation of injury can end up with gangrenous leg that needs amputation
Reduced blood flow below dislocation
what is haemarthrosis hemophilia
inherited condition where there is reduced ability of the blood to clot and can bleed into the joints after trivial trauma
what can be a severe outcome of haemarthrosis hemophilia
End up with joint full of blood and can lead to early arthritis that destroys the join
what is the tibiofibular joint in the ankle responsible for
dorsi/plantar flexion
what is the subtalar joint in the ankle responsible for
inversion/eversion
what is MRI good for in imaging ankles
imaging tendons
what is CT good for in imaging ankles
fractures and reconstructions
what happens if tendons rupture or tear
becomes oedematous
what is osteoarthritis
articular cartilage breakdown causes inflammation in joint
can OA be reversed
no
what does OA affect
entire joint - bone and connective tissues
what is OA treated with
pain relief and joint replacement
what are 7 risk factors for OA
older age F>M obesity joint injuries repeated stress on joint genetics metabolic diseases
what are 7 symptoms of OA
pain stiffness loss of flexibility grating sensation bone spurs around edge of joint swelling depression/sleep disturbances
what are 3 characteristics of OA on images
loss of joint space
osteophytes
sclerotic margins
what can happen to osteophytes in joints in terms of OA
overgrowth of bone can break off into joint
what is rheumatoid arthritis
chronic systemic inflammatory disorder due to autoimmune disorder that affects the synovium of joints
what are 3 characteristics symptoms of rheumatoid arthritis
painful swelling
bone erosion
joint deformity
what does rheumatoid arthritis do to synovial
thickens synovium
what happens to ligaments in rheumatoid arthritis
become lax resulting in joint deformity
what are 4 rheumatoid arthritis symptoms
tender/war/swollen joint
joint stiffness
fatigue/fever/loss of appetite
severity can alter between flares and remission
what is a radiographic characteristic on images in terms of rheumatoid arthritis
symmetrical
what joints do rheumatoid arthritis affect first
smaller joints first
what does rheumatoid arthritis do to the synovium and cartilage/bone
thickens synovium
destroys cartilage and bone
what does rheumatoid arthritis do to tendons and ligaments
weaken and stretch
what are 5 risk factors for rheumatoid arthritis
F>M family hx smoking environmental exposures obesity
what are 7 complications of rheumatoid arthritis
osteoporosis rheumatoid nodules infections dry eyes and mouth abnormal body composition carpal tunnel syndrome heart problems, lung disease, lymphoma
what are 3 things that are characteristic in the appearance of rheumatoid arthritis in images in terms of what the bone looks like
bone looks moth eaten and there are round lesions/multiple areas of lucency where nodules have destroyed the bone
what is gout
deposition of monosodium urate crystals in and around joints
what is clinical presentation of gout
acute gouty - monoarticular red inflamed swollen joint
where does gout normally occur
typically in lower limb usually affecting the first metatarsophalangeal joint
what 2 phases are there with gout
acute phase 7-10days
asymptomatic period between acute flares
what is gout associated with
chronic uncontrolled hyperuricemia and kidney disease
people with gout can develop what
tophaceous gout
chronic inflammatory and destructive changes in surrounding connective tissues
what are tophi
solid urate crystal collections
how to tophi appear on images
radiopaque
what are the 3 radiographic features of gout
punched out lytic bone lesions with overhanging sclerotic margins
periarticular soft tissue swelling due to crystal deposition in tophi around joints
soft tissues swelling may be hyperdense due to crystal
what is joint infection commonly associated with
joint replacement and intervention such as steroid injections
what is joint infection seen as on images
lucency around bone destruction in later stage
pus around prosthetic implant
joint infections with pus around prosthetics will result in what
will be loose so may fall out or bone could break so need to take out joint replacement and put another one in
what is scurvy caused by
vit C deficiency
is scurvy treatable
yes
who is scurvy most prevalent in
low socioeconomic status and smokers
what occurs in scurvy and where do they occur
metaphyseal abnormalities
distal femur and proximal and distal tibia sub ephyseal horizontally oriented foci of lucency with intervening parallel bands of sclerosis
why does low vit c lead to scurvy
low levels of circulating vit C results in poor collagen fiber formation that leads to demineralized bones, microfractures and poor healing
who is ewing sarcoma more common in
<20years
M>F
what is ewings sarcoma associated with
large soft tissue component
where does ewings sarcoma occur in
ribs
limbs
what are the 3 components in ewing sarcoma in radiographic images
bone destruction
onion skinning over periosteum
soft tissue mass
what is pigmented villonodular synovitis in terms of what is affected
diffuse/localized hyperplastic outgrowth of synovial membranes of joints, bursae, tendon sheaths, or combo of these tissues
what can pigmented villonodular synovitis be considered as
benign tumor of the synovium
what can pigmented villonodular synovitis do to the surrounding structures if left untreated
displays aggressive invasion to adjacent bone and cartilage
what is hemosiderosis
disorder of RBC function that results in deposition of iron in bones
hoe does hemosiderosis appear on images
dark areas on T2 MRI due to iron deposits
what is sickle cell disease
disorder of haemaglobin in RBC
wat is sickle cell disease caused by
deformation and early destruction of red cells
what can sickle cell disease lead to
ischemia and infarcts
how can sickle cell disease appear on imaging
diffuse diminished bone density with prominent trabecular pattern of spine and pelvic bones
