Bone disorders Flashcards
What are common bone disorders?
Osteoporosis
Osteogenesis imperfecta
Fibrodisplasia ossificans progressiva
What is the epidimeology of osteoporosis?
Aging population
Predominantly female patients
What are possible reasons for increased prevalence of ostoporosis in females?
Oestrogen deficiency - menopause
Is osteoporosis an acquired disease?
Yes
What type of bone is more affected by osteoporosis?
Spongy, trabecular bone is more affected that cortical bone
What are the two types of osteoporosis that exists?
Primary osteoporosis - not caused by underlying disease
Secondary osteoporosis - caused by medication/ immobilisation or impaired dietary calcium uptake
What are characteristics of osteoarthritis?
Articular cartilage loss
Subchondral bone thickening
Osteophyte formation
What are osteophytes?
Bony projection associated with degeneration of cartilage joints
What is abnormal in osteoarthritic articular cartilage?
Decreased concentration in collagen type-II
Decreased aggrecan integrity
In OA, there is increased formation of hydroxyapatite
TRUE or FALSE
TRUE
Consistent with hypertrophic chondrocyte changes
What is a key marker of chondrocyte hypertrophy?
MMP13
Critical target for OA research
WNT signalling pathway are important regulators of MMP13
What are treatments of OA?
Blocking bone resorption
Hormone replacement therapy - target decreased oestrogen
What is a way to block bone resorption?
Biphosphonates
Bind to hydroxyapatite and reduce activity and formation of osteoclasts
What is osteogenesis imperfecta?
Genetic disorder
Autosomal recessive and dominant forms (1:20 000)
What is OI caused by?
Mutations affecting Collagen type I biosynthesis
What are the symptoms of OI?
Brittle bones
Prone to fractures
What are the treatments for OI?
Biphosphonates
Surgery
Physical therapy
No curative treatments available
What is Fibrodisplasia ossificans progressiva?
Very rare genetic condition
Autosomal dominant
Median age of survival = 40 years
What causes FOP?
Consistently active BMP-receptor type I
Transformation of connective and muscle tissue into bone - ectopic ossification
What are the treatment options available for FOP?
Surgical removal attempts
Clinical testing - small-molecule kinase inhibitors designed to selectively block ACVR1
Why do surgical removal of bone in FOP lead to worsening of condition?
Any insult to tissue results in ectopic bone formation
