Week 6 - Bone diseases

What is cause of Paget's Disease?

-Genetic mutation -Early exposure to measles virus (persistent infection) -Nobody is 100% sure -Associated with osteosarcoma 1% of patients -genetic predisposition). Genes associated with this condition are the sequestosome 1 gene, the TNFRSFIIA gene that codes for the RANK protein, and the VCP gene. The exact role that these genes play in the development of the disorder is unknown.

Describe the presentation of osteosarcoma ? How common is it ? What is survival likelihood?

-Highly variable presentation from hard and bony, through fibrous to soft and haemorrhagic -Peak incidence 10-25 years and 40+ years -5 year survival -Localised 74% -Distant 27%

What are histology of paget's disease ?

-Increased osteoclast activity followed by -Abnormal hyperplasia -Immature woven bone is laid down -Thickened trabecular follow -Disorganised cement lines appear in the bone due to haphazard deposition -Bone lacks strength and leads to fractures

What is the histology of osteomalacia ?

-Need to cut an decalcified bone section -Bone shows reduced mineralisation but mass appears normal -Osteoid (non- mineralised bone) seams are significantly wider than normal

What are symptoms of osteomalacia and rickets ?

-Vague and generalised -Muscle weakness -Bilateral/ symmetrical fractures

What is osteosarcoma?

A cancer of the bone that usually affects the large bones of the arm or leg. It occurs most commonly in young people and affects more males than females. Also called osteogenic sarcoma.

What are the symptoms of bone diseases?

Asymptomatic initially Gradual onset with reduction in height (Vertebra) Low impact fracture of wrist or hip

What are the causes of osteosarcoma ?

As with many forms of cancer, the exact, underlying cause of osteosarcoma is unknown in most individuals. In most children and adolescents, this cancer is thought to occur randomly, for no specific reason (sporadically). Sporadic occurrence of cancer is thought to occur because of multiple factors acting together ?

What is the histology of osteoporosis?

Bone is normally mineralised but mass is decreased Affects the entire skeleton Bone resorption is increased Bone formation levels are normal (but age reduces)

What are the causes or risk factors of osteoporosis?

Causes Age → Menopause with the drop in estrogen Endocrine issues (Hyperthryoidism, Type 1 diabetes) Tumours GI issues (malnutritions, malabsorption) Many risk factors are associated with osteoporotic fracture, including low peak bone mass, hormonal factors, the use of certain drugs (eg, glucocorticoids), cigarette smoking, low physical activity, low intake of calcium and vitamin D, race, small body size, and a personal or a family history of fracture.

What are signs and symptoms of paget's disease?

Early symptoms of Paget's disease include bone pain, joint pain (especially in the back, hips and knees), and headache. Physical signs include enlargement and bowing of the thighs (femurs) and lower legs (tibias), and enlargement of the skull in the area of the forehead. Most individuals with Paget's disease do not have any symptoms (asymptomatic) or only develop mild symptoms.

What are the causes of osteomalacia?

Lack of dietary calcium/ Vitamin D in children Rarely inborn metabolic errors (genetic) Rarely soft tissue tumours Concern of huge increase of diseases

Define osteoporosis? Explain what it is?

Osteoporosis is a skeletal disorder characterised by low bone density and micro-architectural deterioration of bony tissue. This results in an increase in fracture risk.1 The resulting fractures pose a major health problem. Hip, vertebral, and wrist fractures are most commonly associated with osteoporosis.

Explain and describe what is paget's disease?

Paget's disease of bone is a chronic, slowly progressive skeletal condition of abnormally rapid bone destruction (osteolytic) and reformation (osteoblastic). The new bone may occur in one or more regions of the body and is structurally abnormal, dense and fragile. This abnormal development may cause bone pain, arthritis, deformities and fractures. The bones most frequently affected are in the spine, skull, pelvis and lower legs. The exact cause of Paget's disease is not known.

Define primary and secondary bone tumours?

Primary bone cancer - This means that the cancer starts in the bone. fact sheet. Secondary bone cancer - This means the cancer started in another part of the body but has now spread (metastasised) to the bone. It may also be called metastatic bone cancer, bone metastases or bone mets. -Because of its blood supply, bone is a site for secondary tumour deposits

Describe the osteomalacia?

Skeletal deformities - thickening of the ankles, wrists and knees, bowed legs, soft skull bones and, rarely, bending of the spine. dental problems - including weak tooth enamel, delay in teeth coming through and increased risk of cavities

Describe and Explain osteomalacia ?

Vitamin D deficiency accounts for the most common nutritional deficiency among children and adults. Osteomalacia describes a disorder of "bone softening" in adults that is usually due to prolonged deficiency of vitamin D. This results in abnormal osteoid mineralization. This activity describes osteomalacia and its respective causes, clinical presentation, evaluation, and management.

The signs and symptoms of osteosarcoma?

The most commonly affected bones are the long bones of the legs. These are the femur and the tibia. The femur, also called the thighbone, runs from the hip to the knee, and the tibia, or shinbone, runs from the knee to the ankle. The femur and the tibia meet at the knee where they help to form the knee joint. Osteosarcomas can form where these bones are growing the fastest in children and adolescents, which is called the growth plate. About 50% of individuals develop an osteosarcoma around the knee.