T10-L2: Diseases of the Musculoskeletal System Flashcards
What embryological layer is soft tissue derived from?
Mesoderm
What is the term for malignant mesodermal tumours?
Sarcomas - These account for 1% of malignancies. Congenital tumours rarely behave malignantly even with aggressive features. Lymph node involvement is uncommon.
How do we diagnose soft tissue tumours?
- Imaging - ultrasound guises core biopsy
- Wide excision
- Cytogenetics
- Molecular genetics such as FISH, PCR and RT-PCR
What is CREST syndrome?
CREST syndrome, also known as the limited cutaneous form of systemic sclerosis (lcSSc), is a multisystem connective tissue disorder. The acronym “CREST” refers to the five main features: calcinosis, Raynaud’s phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia.
What condition is Polymalgia rheumatic associated with?
Temporal Arteritis
What is malignant hyperthermia?
Inherited disease – fast rise in body temperature and severe muscle contraction when the affected person gets general anaesthesia.
Give aetiologies of Rhabdomyolysis.
This is the destruction of skeletal muscle. This leads to Release of muscle fibre and myoglobin content into blood. The myoglobin is filtered through the kidney and enters urine leading to - myoglobinuria- brown urine
This is not always a disease, other causes include: • Trauma, crush injuries • Drugs- cocaine, amphetamine • Extreme temperature • Severe exertion-marathon running • Lengthy surgery • Severe dehydration • Important complication- acute renal failure
On its own it is not a dangerous disease. It can be transient but if not treated properly it can lead to renal failure. This is particularly important in a RTA. Hydration is therefore important.
What is the pathogenesis of osteoarthritis?
There is deterioration or loss of cartilage that acts as a protective cushion in between bone. As the cartilage is worn away forming spurs. Fluid filled cysts in the marrow form known as subchondral cysts. Together this results in pain and limitation of movements.
OA begins in the chondrocytes. Chondrocytes produce interleukin-1 which initiates matrix breakdown. Prostaglandin derivatives induces the release of lytic enzymes and so prevents matrix synthesis.
Primary OA is an abnormal stress in the weight bearing joints. This affects fingers, knees, cervical and lumbar spines. It can also involve the fingers - Herberden’s or Bouchard’s nodes.
What is the pathogenesis of rheumatoid arthritis?
It is a chronic systemic autoimmune condition. It is CD4+ cell mediated. Other causes include viruses such as EBV and Borrelia.
It leads to a non-suppurative (pus) proliferative synovitis which causes destruction of articular cartilage and ankylosis (stiffness) of joints. It is cytokine mediated - IL6, TNF-alpha and TNF-beta. It also affects skin, muscles, heart, lungs and blood vessels.
What is the clinical presentation of gout?
Transient attacks of acute arthritis are due to crystallization of urates within and about joints, leading to chronic gouty arthritis and deposition of masses of urates in joints and other sites- tophi. It can also lead to gouty nephropathy.
This can present as severe attacks of pain, swelling, redness and tenderness in one or more joints, most often in the big toe.
What is the aetiology of pyogenic osteomyelitis?
It is caused by a bacteria that uses haematogenous spread. It can be from an excision at a contiguous site or through direct implantation.
What is the aetiology of infective arthritis?
Aetiology includes Bacterial-Staphylococcus, Streptococcus, Gonococcus, Mycobacteria,
Risk factors include trauma, IV drug abuse, debilitating illness.
Give secondary caused of osteoporosis.
Secondary causes include endocrine disorders such as HPT and Type 1 diabetes. Other causes include neoplasia such as in the case of multiple myeloma and malnutrition.
What is Paget’s disease?
here is a net gain in bone mass as there is predominant osteoblastic activity with burnt out osteosclerotic activity (due to osteoclast dysfunction). It initially begins with a initial osteolytic stage followed by the predominant osteoblastic activity. Newly formed bone is disordered and mechanically unsound.
Paget’s disease begins I the 5th decade. It more commonly affects males than females. Axial skeleton and proximal skeleton is most commonly affected. Pain is the most common symptom. Chalk stick type fractures are common.
What is osteomalacia?
Causes defects in matrix mineralization due to a lack of Vitamin D. There is decreased bone density (osteopenia). Skeletal deformities are not seen.
