Disorders Of Bone Health (otesoporosis) Flashcards

Question

Calcium and Vitamin D (6)

Answer 1

reduce risk of non-vertebral fractures in patients who are at risk of deficiency due to insufficient dietary intake or limited sunlight exposure. If low exposure to sun or house-bound: -consider at risk of Vitamin D deficiency Calcium supplements should not be taken within 2 hours of oral bisphosphonates If dietary calcium is adequate, >700 mg daily Vitamin D only may be preferred as the osteoporosis treatment adjunct

Answer 2

analogues of pyrophosphate that adsorb onto bone within the matrix ingested by osteoclasts leading to cell death thereby inhibiting bone resorption Anti-resorptive agents – alendronate and risedronate

Answer 3

increases BMD by 5-8% Prevent bone loss at all sites vulnerable to osteoporosis Reduce risk of hip and spine fracture reduce the risk of fragility fracture by ~50% in patients with post-menopausal osteoporosis

Answer 4

Good data for benefit for 5 years (10 y if vertebral fracture) Long-term concerns re: osteonecrosis of the jaw, atypical fractures Consider “bone holiday” – though no robust evidence base

Answer 5

Bone undergoes a cycle of remodelling in a programmed sequence at discrete foci called bone remodelling units 1.osteoclasts appear on a previously inactive surface and begin to resorb the bone 2.Osteoclasts are then replaced by osteoblasts that fill the cavity by putting down osteoid that is mineralised to form new bone 3.After a normal bone remodelling cycle the resorption cavity is completely refilled with new bone 4.However, in osteoporosis, there is a relative or absolute increase in resorption over formation that leads to increased bone loss __________

Answer 6

Once yearly IV infusion for 3 years 1 in 3 acute phase reaction with first infusion – paracetamol ~ 70% reduction in vertebral fracture, 40% reduction in hip fracture Consider if intolerant of oral bisphosphonates or unable to comply with dosing regime

Answer 7

fully human monoclonal antibody that targets and binds with high affinity and specificity to RANKL (receptor activator of nuclear factor-kB ligand) prevents activation of its receptor, RANK, inhibiting development and activity of osteoclasts, decreasing bone resorption and increasing bone density.

Answer 8

Subcutaneous injection 6 monthly Compared to placebo, reduces risk of vertebral fracture by ~68%, hip fracture by 40% and non-vertebral fracture by ~20%. Adverse effects: Hypocalcaemia, eczema, cellulitis No contraindication in severe renal impairment

Answer 9

consider treatment with antiresorptive therapy when T score /=7.5mg prednisolone for 3 months or more or if there is a prevalent vertebral fracture, consider treatment with T score < -1.5 as fracture risk increased

Answer 10

may be a viral/environmental/biomechanical trigger in genetically predisposed individual Rare < 40 y; incidence increases with age: > 55y: 3% of UK population >85y: ~ 10%

Answer 11

long bones pelvis lumbar spine skull predominantly

Answer 12

Presents with= -bone pain -deformity -deafness -compression neuropathies Osteosarcoma is a rare complication incidental finding on - X-ray (XR) -isolated high alkaline phosphatase

Answer 13

Diagnose on XR; -isotope bone scan shows the distribution of disease -biochemistry shows raised alkaline phosphatase with otherwise normal LFTs

Answer 14

Treat with bisphosphonates if pain not responding to analgesia

Answer 15

Rare group of genetic disorders mainly affecting bone Most are secondary to mutations of type 1 collagen genes (COL1A1, COL1A2) Most are autosomal dominant inheritance At least 8 types, of varying severity Type 1: mild Type 2: neonatal (lethal) Types 3 and 4: very severe

Answer 16

May be associated= -blue sclerae -dentinogenesis imperfecta more severe forms present with fractures in childhood mild form may not present until adulthood Important differential diagnosis for suspected non-accidental injury

Answer 17

There is no cure only = -fracture fixation -surgery to correct deformities -bisphosphonates