Bone diseases Flashcards
What are the two necrotising bone diseases we need to know?
Osteochondritis Avascular Necrosis (AVN)
What is osteochondritis?
Inflammation of bone/cartilage due to interrupted blood supply leading to necrosis.
What causes the interrupted blood supply in osteochondritis?
Repeated movement or traction injury compressing blood vessels.
What are some of the signs osteochondritis can cause?
Compression and fragmentation of bone (osteochondritis dissecans)
Separation from periosteum
Pain
What are the common sites for osteochondritis to present?
2nd metatarsal Navicular Lunate Capitellum of elbow Perthes disease in hip Often occurs at apophysis (where tendons attach)
How do you treat osteochondritis?
Pin
Osteotomy
Remove fragments
What group is most affected by osteochondritis?
Children
What is avascular necrosis?
Ischemic necrosis of bone
What are the common sites to find avascular necrosis?
Femoral head and condyles, head of humerus, capitellum, scaphoid, talus
What are common causes of avascular necrosis?
Idiopathic, fractures, thrombophilia, sickle cell, SLE, decompression sickness, alcohol, steroids, hyperlipidemia (last 3 due to fat sludging up vessels)
How do you diagnose and treat avascular necrosis?
Early- MRI and decompress bone
Late- Damage done therefore replace.
What are the five biochemical diseases of bone we need to know?
Osteoporosis Osteomalacia and Rickets Hyperparathyroidism Renal Dystrophy Paget's Disease
What is osteoporosis?
Decreased bone mineral density and increased porosi weakens bone.
2.5 standard deviations less than mean peak for race and sex.
Occurs naturally as part of aging.
What is osteopenia?
A milder form of osteoporosis. 1-2.5 deviations left.
What are the two types of osteoporosis?
Type 1- Post menopausal
Type 2- Occurs due to aging
What are some risk factors for developing osteoporosis?
Smoking, alcohol, poor diet, inactivity, lack of VD.
How do you diagnose osteoporosis?
DEXA scanning for bone density.
Serum Ca and P must be normal.
How do you treat osteoporosis?
Cannot restore bone density but Ca and VD supplements, bisphosphonates, denosumab and strontium can slow the disease.
What is osteomalacia and rickets?
Softening of bone cue to lack of Ca and P.
What age group is osteomalacia found in?
Adults
What age group is rickets found in?
Children
What causes osteomalacia/rickets?
Lack of dietary Ca, insufficient VD or P loss due to kidney disease (refeeding syndrome, alcohol, anticonvulsants)
What are the symptoms of osteomalacia/rickets?
Bone pain, deformities, multiple fractures, hypocalcemia, (muscle cramps, fatigue, brittle nails), abnormal blood chemistry (decreased Ca and P, increased ALP)
What is the treatment for osteomalacia/rickets?
VD therapy and Ca/P supplements
What is hyperparathyroidism?
Overactive parathyroid glands produce increased PTH.
What are the three forms of Hyperparathyroidism?
Primary- Benign adenoma or hyperplastic disorder
Secondary- Physiological over production due to hypocalcemia
Tertiary- Chronic secondary who develop adenoma.
How does hyperparathyroidism present?
Fatigue, depression, bone pain, thirst, renal stones, fragine bones and lytic lesions.
How do you diagnose hyperparathyroidism?
Increased serum PTH and Ca. Low or normal P.
How do you treat hyperparathyroidism?
Remove adenomatous gland and treat underlying cause.
What is renal dystrophy?
CKD -> Decrease P excretion and VD activation -> Secondary HPTism -> Osteomalacia.
What is Paget’s Disease?
Excessive osteoclast activity leads to increased bone turnover which doesn’t remodel.
What causes Paget’s Disease?
Viral infection and genetics.
What bones are commonly affected by Paget’s Disease?
Pelvis, femur, skull, tibia and ear ossicles.
What does Paget’s disease do to bone?
Thickened, brittle and misshapen bones.
How does Paget’s disease present?
Can be asymptomatic or cause arthritis, fractures, deformities, pain and cardiac failure.
What age group does Paget’s Disease usually affect?
50-70 YO
How do you detect Paget’s Disease?
Increased serum ALP, normal serum Ca and P. XR
How do you treat Paget’s Disease?
Bisphosphonates or calcitonin. Joint replacement and fracture repair.
