Review of CT Conditions Flashcards
Where is the CT in muscles?
- dense regular CT sheaths around muscle fibres, groups of muscle fibres and muscle groups
What is tendinitis?
- small tears to tendon causing a localised inflammation in tendon as repair mechanism
What are the causes of tendinitis?
- overuse
- collagen disorders (marfan’s)
- renal dialysis (as affects clearance and new production of collagen)
What are the common sites of tendinitis?
- lateral epicondylitis (Tennis elbow, extensor muscles attach)
- achilles tendonitis
- supraspinatus tendinitis
- anywhere there is a tendon
What is the treatment for tendinitis?
- rest, ice, compression, elevation (RICE)
- analgesia and NSAIDs
- stretching (otherwise forms unorganised collagen bundles as it forms)
- surgery
What is tendinosis?
- chronic injury and failed healing
- disorganised collagen can make tendon weaker
- can lead to full thickness tears
- swelling 2-6cm above insertion point in belly
What is heterotopic ossification?
- caused by achilles tendinitis
- partial tears in achilles tendon may heal forming heterotopic calcified regions
- due to inflammatory process so give COX2 inhibitors
What is the mechanism of heterotopic ossification?
- inflammatory mediators induce differentiation of mesenchymal stem cells to chondrocytes via COX2
- chondrocytes undergo hyperplasia and secrete osteoblastic factors like RANKL = osteogenesis, osteoclast recruitment, angiogenesis
- previously damaged tendon which is calcified becomes more brittle and may rupture
- COX2 inhibitors prevents these complications and reduces symptoms
Why does slow healing of tendons occur after injury?
- tendons relatively avascular
What are the extrinsic factors of tendon healing?
- peripheral fibroblasts
- for achilles, rotator cuffs as open/extrinsic
What are the intrinsic factors of tendon healing?
- fibroblasts from tendon itself
- hand flexors, any tendon covered by tendon sheath
- takes longer than extrinsic as no way for peripheral mediators to enter
- intrinsic as wrapped in tendon sheath
What is enthesis?
- sites where ligaments/tendons insert into bone
- fibrous or fibrocartilaginous
What is fibrous enthesis?
- fibrous tissue joins/extends directly to bone going through periosteum
- collagen fibres coated with calcium hydroxyapatite (sharpey’s fibres)
- when joint does not undergo a lot of movement
- insert a long distance from joint
- tendon ligament not moved by joint movement
What is fibrocartilaginous enthesis?
- transitional material transitions through fibrocartilage regions
- gradual change from tendon to bone
- helps stiffen tendon/ligament (ensures any bending of tendon/ligament fibres during joint movements is spread gently away from bone)
- inserts closely to joint allowing movement
- majority of tendon
What is enthesitis?
- inflammation of enthesis
- can occur at any point of attachment for tendon/ligament inserting into bone
What causes enthesitis?
- recurring stress
- autoimmune disease (spondyloarthritides, HLAB27 arthropathies)
- interaction with different types of stress produces pro-inflammatory cytokines and danger PAMPS
- activate inflammatory cells to produce cytokines at specific tissues sites (enthesis)
What is the pathogenesis of enthesitis?
- normal enthesis inserts into porous bone at location with small transcortical vessels
- in mechanical trauma these vessels become inflamed =
vasodilation, efflux of immune cells (neutrophils), osteoblasts form bone at enthesis
What are some comorbidities of enthesitis?
- IBS
- psoriatic arthritis
- ankylosing spondylitis
cytokines from gut or other arthritis conditions can travel to enthesis and cause damage
What is the key difference between enthesitis and tendinitis?
- tendinitis occurs halfway from muscle to insertion point at belly
- enthesis occurs at insertion point itself, further down achilles
What are the difference between enthesophytes and osteophytes?
- enthesophytes originate from insertion point of tendon into bone (articular border not involved)
- osteophytes originate from border of articular cartilage, at joint margins
What is the mechanical treatment of enthesitis?
- RICE
- NSAIDs
What is the inflammatory treatment of enthesitis?
- DMARDs
- anti-TNF therapy
- local radiotherapy
- corticosteroid injection
- injection of hyperosmolar dextrose
What DMARDs are used for enthesitis?
- sulfasalazine = prevents systemic release of pro-inflammatory enzymes from gut
- methotrexate
When can anti-TNF therapy be used for enthesitis?
- cannot be used for isolated
- can be used when multiple joints affected
- ankylosing spondylitis and psoriatic arthritis
- for severe autoimmune enthesitis
Why are injections of hyperosmolar dextrose used for enthesitis?
- irritant to cause proliferation of intrinsic fibroblasts
- higher rate of healing before it gets ossified
What is the function of the tendon sheath?
- protects and nourishes tendons
- cushions tendons
- guides tendons
- allows only tendon nutrition
What supplies nutrients to the tendon?
- synovial fluid from tendosynovial sheath
- vincula blood supply via mesotendon
What is tenosynovitis?
- trigger finger (enlargement of tendon within sheath so tendon stuck, when make a fist then open finger stays as extensor tendon stuck then all of a sudden snaps back into place as muscle works)
- de quervain’s tenosynovitis
- isolated inflammation
- fibrosis and narrowing of tendon sheath
- tendon and sheath rubbing over radial styloid process
What is the treatment for tenosynovitis?
- RICE
- splinting
- anti-inflammatories
- corticosteroid injections
- surgery = cut annular ligament for chronic trigger finger, shave down radial styloid process
What are the signs and symptoms of systemic lupus erythematosus?
- non-specific fatigue
- fever
- arthralgia weight changes
- dermatological changes
What is undifferentiated CT disease?
- rheumatoid arthritis (affecting synovial membrane)
- Systemic Lupus erythematosus
- Scleroderma
- Sjogrens
What specific symptoms are there of systemic lupus erythematosus?
- affects soft tissue around small joints of hands, wrist, knees
- migratory asymmetrical pain not related to swelling
- malar facial rash in butterfly pattern extending over cheeks and bridge of nose, worse when exposed to UV light
- photosensitivity
- discoid lesions
- alopecia
- Jaccoud arthropathy (hand deformities due to tendinitis/tenosynovitis), swan neck and Z shape thumb like RA but can straighten them out
What symptoms of lupus erythematosus are non-specific?
- renal nephritic disease
- neuropsychiatric
- pulmonary
- GI
- cardiac
- hematologic (immune complexes cause damage to blood vessels and CT, risk to any tissue with rich capillary network)
How is lupus erythematosus diagnosed?
- positive for ANA (anti-nuclear antigens)
- stain
- homogenous antigen double stranded DNA
- speckled SS-A/RO
How is lupus erythematous treated?
- NSAIDs = mild to moderate
- DMARDs = moderate to severe and flares
- Biologicals (belimumab, rituximab)
- Corticosteroids (flares)
- IV immunoglobin
What DMARDs are used for lupus erythematous?
- cyclophosphamide
- mycophenolate mofetil
What is the myotendinous junction?
- go from striated skeletal muscle to tendon
- CT connects to form tendon continuing
- more damage to muscle here so more repair going on = more centrally located nuclei
- tenocytes are fibroblasts in tendons making collagen I
What is the significance of SLE and antibodies?
- CT disease
- more common in black people
- linked to anti-nucelear antigen antibodies
- against intranuclear proteins = deoxyribonucleic acid and ribonucleoproteins
