Diseases Flashcards
Osteogenesis Imperfecta (OI)
Abnormal Type 1 Collagen
Brittle Bone Disease, Blue Sclera
brittle bone disease, genetic defect in type I collagen, varied clinical signs, at risk for fracture, stature abnormalities if not reached skeletal maturity, **blue sclera ** (collagen is thin so can see through), misshape bones, joint laxity, abnormalities in hearing and dentition
Achondroplasia
FGFR3 Gene
Shortened Limbs
FGFR3 Gene inhibiting endochondral growth, shortened limbs with normal head size, thanatophoric dysplasia (lethal + severe form of achondroplasia
Osgood-Schlatter Disease (OI)
**detachment at tibial tuberosity ** via ligament with patellar tendon, growth of long bone doesn’t match the patellar tendon, skeletal maturity stops it, chronic pain in knees, bump below patella
Fracture Callus/Reactive Bone
callus is healing of area after fracture, osteoprogenitor cells migrate to that area and lay down new cartilage precursors to form immature bone and bridge the fraction of the long bone, healing bone looks like a bone tumor (both are destroying bone and making callous)
Avascular Necrosis/Bone Infarction
blood supply cut off to bone, necrotic bone and cartilage will separate, common in the femur, lots of pain in this area with bone breaking off or cartilage flaking away, bone will have a blunted look after healing
Osteomyelitis
Inflammation of bone & bone marrow from potiental infectious process - diabetes
inflammation of the bone, infectious process, diabetes – poor wound healing will ulcer and can cause this and possibly lead to amputation, central bone destruction (sequestrum), bone around periphery will thicken (sclerotic rim of bone, involucrum), more blue is inflammation or neoplasia in this it would be inflammation, triangular shape above that bone creates
Acute: Neutrophil (predominant), sequestrum, abscess within bone
Chronic: lymphocytes & plasma cells
Staph. Aureus
Renal Osteodystrophy
renal cause dystrophy, less Ca in serum releases PTH to take from bone and take to kidney and intestine, can be a futile cycle if decreased serum caused by kidney uptake causing bone destruction from excessive PTH
High-turnover (increased bone resorption and production), low-turnover (tired or burn out BM)
**Kidney tubular dysfunction – renal tubular acidosis → dissolution of hydroxyapatite → bone matrix demineralization and osteomalacia **
Reduced phosphate excretion/hyperphosphatemia and **decreased calcium **reabsorption/hypocalcemia → ↑ PTH secretion with clinical secondary
hyperparathyroidism, including active bone turnover and brown tumor formation
Decreased biosynthesis functioning →** ↓ Vitamin D activation** → ↓ calcium absorption through intestinal and bone processes → hypocalcemia →** secondary hyperparathyroidism**
Osteoporosis (compression fracture)
Decreased bone mass, fragility, and increased fracture due to imbalance with OB&OC
decreased bone mass, body’s ability to produce things in the same quality is reduced, homeostasis does not stay the same, postmenopausal and Asian women, fractures more likely, less dense look in the bone, loss of trabeculae, apple core look from decreasing bone, corticosteroid therapy can cause it, treat with exercise and Ca/Vit D supplements
Osteomalacia/Vit D deficiency/ Rickets
LowVit D –> Low Ca –> PTH rises –> OC activity - bone mienralization
Adults: Calcifed trabecular bone with excessive amounts of unmineralized ostoid
Children: Low Osteoid mineralization (genu varum)
impaired bone mineralization, from low Vit D so gut taking up Ca and **less serum Ca **causing PTH to rise and bone to break down from osteoclasts, Osteomalacia in adults and
Rickets in children, in children there is visible skeletal abnormalities:** bowed legs (weak)/**decreased pulmonary function/rachitic rosary (deficiency across costal chondral junction, beads along ribcage)/sternum projects out (pigeon breast deformity/pectus carinatum)
Osteopetrosis (Genetics)
Hereditary, OC affected, Fractures, causes thick scleotic bone
affects osteoclast maturation, causes thick and sclerotic bone, reduced acidification in the pits does not allow for the breakdown of bone, foramen narrow and nerves can get impinged, many fractures, radiographic picture is too white because signal of x-ray does not go all the way through, Erlenmeyer flask deformity
Paget Disease
Chronic disease of excessive OC producing thick shaped fractures, OC-Mixed-OB
genetic, excessive turnover and bone deposition at the same time, makes bones structurally unsound, osteoclastic early and osteoblastic late, more common in Caucasian and older ages, fractures, cells can acquire mutation from all this turnover and grow a neoplasia to grow a sarcoma, one (monostotic/cranium) or many (polyostotic) locations, needs cranium, serum has urinary hydroxyproline (collagen) and alkaline phosphatase, haphazard arrangement of the bony lamella
Hyperparathyroidism/Osteitis Fibrosis Cystica
elevated PTH, increases bone turnover and breakdown, tumor in parathyroid can secrete PTH and cause bone problems, remove it in surgery and wait to see when PTH levels normalize to know you got all of the tumor, dissecting osteitis grow along medullary trabeculae, brown tumor starts to look like a mass from too much of this, bone not as white as it should be in distal digits (osteopenia), giant cells
Osteoarthritis
degenerative joint disease, not much inflammation, might be only one joint, usually not bilateral, occurs late in day, crepitus (cracking), osteophyte development which is new growth near articular surface, hips/knees/fingers (DIP Heberden nodes), loss of cartilage where bone rubs on bone (eburnation), on microscope the cartilage is gone
RA
extensive inflammation of synovium, autoimmune disease, citrullinated peptides with CCP autoantibodies and RF with IgM or IgA autoantibodies attacking your own IgG, younger age range, more female, more than one joint and bilateral usually wrist/fingers, morning pain with joint stiffness getting better throughout the day, pannus in the joint (inflammatory material) which gets replaced by scar tissue (ankylosis) and causes joint to not be able to move
Ankylosing Spondylitis
nothing in serum is autoimmune, HLA-B27 allelic positivity, bones are fusing because joints ossified, younger males, sacroiliac is most common, reactive arthritis is ankle/knees/feet, enteropathic arthritis is GI, psoriatic arthritis is skin
