Pathophysiology Flashcards

Question

What other hormones play a part but minor in terms of bone growth?

Answer 1

Glucocorticoids decrease bone formation and increase bone resorption by inhibiting protein synthesis. There is significant bone loss in untreated diabetes msllitus Hypercalcaemia is a common effect of cancer (Ca withdrawn from bone). Bone metastases cause local erosion. And some tumours produce substances with PTH type activity

Answer 2

``` Compound Torus Avulsion Compression Comminuted Pathological Stress (buttressing effect) Intra-articular (extends into joints, risk of developing 2 deg OA) Occult fractures (easily missed. Use CT if overlying strictures present. If non-displaced and no cortical disruption like stress, use MRI) ```

Answer 3

``` Transverse Oblique Spiral (multiple views needed) Greenstick Segmental ```

Answer 4

Haematoma formation - occurs with vessel damage - fibrin (protein substance involved in clotting of blood) forms initial framework for healing. Tissue damage = fibrinogen converted into fibrin at wound Procallus - fibroblasts, osteoblasts and capillaries move into the wound to produce granulation tissue Callus - osteoblasts deposit disorganised clumps of primitive bone matrix (woven bone). This is the callus Formation of normal bone with replacement of woven bone Remodelling of periosteal and endosteal surfaces

Answer 5

Local blood supply Type of fracture - ie. spiral/oblique faster healing than transverse. Comminuted fracture can have avascular fragment that become sequestrated. Fixation - quality determines healing time. - movemntment May lead to non union - IM pins may disrupt blood supply Age Concurrent infection, disease, nutritional status

Answer 6

Continuity of cortex Calcified complete bridge of callus No visible line (Process of 6weeks with adequate fixation)

Answer 7

Delayed union - due to motion, infection, age, pathological fracture Non union - due to motion, avascularity, infection Signs of non union - smooth sclerotic edges with no callus - sealed medullary cavity - pseudoarthrosis (failure of fusion) Malunion - deformity of bone - due to improper reduction or rotation or collapse during healing

Answer 8

``` Apalsia = failure to form Hypopalsia = fail to grow to normal size Dysplasia = abnormal growth Hyperplasia = overgrowth ```

Answer 9

Incomplete closure of neural arches (mostly in lumbosacral) May cause minor sensory loss (paraplegia) Often only detected on X-ray

Answer 10

Scoliosis = lateral spine curvature Kyphosis = more posterioly curved

Answer 11

Abnormal bone structure caused by altered or inadequate biochemical reactions due to genetics, diet, hormones Ie. osteoporosis, osteomalacia,

Answer 12

Density or mass of bone reduced, but bone remains normal - bone loss is generalised or regional - spongy bone is worse affected - women more suspectible than men: postmenopausal osteoporosis due to lack of Oestrogen. Oestrogen desensitises osteoclasts to PTH Causes: Hypertparahyroidism can cause it Low Ca diet (excessive Ca can depress VitD and PTH) High cortisol levels (ie. corticosteroid supplements or Cushings disease can decrease bone mass)

Answer 13

Associated with disuse or immobilisation After 8 weeks, significant osteoporosis is present although it will develop faster in <20 yo and >50 yo

Answer 14

Spinal radiographs = vertebral deformity and decreased density Bone density analysis = post menopausal women in upper 3rd of population not at risk. Bone density should be > 100 mg/cm3 for compression fractures not to occur

Answer 15

Associated with a lack of VitD Osteoid production occurs, but conversion of osteoid to bone is inadequate. Thus differntiating from osteoporosis Due to: - poor mineral intake - lack of sunlight - renal or hepatic disease including biliary obstruction Known as rickets in children

Answer 16

Benign or malignant They can be primary or secondary ``` Primary: vast majority are benign, young patients = most are benign Older patients = most are malignant Slight male predominance ``` secondary tumours: metastatic (more common than primary) spread of adjacent neoplasms, malignant transformation of pre-existing benign lesions Metastatic cancers are usually multifocal, adults (over 40 yo) (prostate, breast, kidney, lung), children (in 1st decade)

Answer 17

Bones involved Specific site involved (cortex or medulla, epiphysis, diaphysis, or metaphysis) Tumour margin and contour

Answer 18

Least amount of pathological damage occurs within benign tumours as they are localised and well defined geographic borders They oress on surrounding structures causing compression and displacement, and even stress fractures Invasive, illdegined tumours = malignant

Answer 19

Malignant 90% in metaphysis of long bone, especially distal femur Common = < 20 and >60 On radiographs: moth eaten sunburst appearance

Answer 20

Occurs in metaphysis and diaphysis Of long bones (esp. medullary cavity of femur, humerus and pelvis) Causes a lucent defect in bone Occurs in middle age and older

Answer 21

Occurs in middle age, rare Metaphysis of femur and tibia Lucent lesions with cortical destruction

Answer 22

Affects older than 50 Vertebrae involved

Answer 23

Tumours of the breast, prostate and thyroid commonly metastasise to the bone

Answer 24

Bacterial infection with staph aureus (common pathogen), affects children (growth plates of limbs usually) and elderly (metaphysis) Exogenous infection: direct penetration of open wound Haematogemous infection: spread from distant sites of body Intense inflammation caused by periosteal elevation and draining sinuses in skin. AVN of bone fragments common leading to sequestrum formation. Children; layer of new bone around site (involucrum)