Flashcards in Diseases of the musculoskeletal system 1 Deck (50):
What is arthritides?
- Pain and stiffness of a joint
- Inflammation of the joint
- Not a single disease
- Hundreds of diseases- causing pain and stiffness of the musculoskeletal system
What is the main difference between acute and chronic arthritis?
- Acute arthritis-Pain, heat, redness and swelling
- Chronic arthritis- commonest types- Osteoarthritis & Rheumatoid arthritis
What is osteoarthritis?
- Degenerative joint disease
- Progressive erosion of articular cartilage
- Results in the formation of bony spurs and cysts at the margins of joints
- Knees and hands in women and hip in men
What is secondary OA?
- Knee in basket ball players and elbow in baseball players
- Underlying systemic diseases such as diabetes and marked obesity
What is the pathogenesis of OA?
- Deterioration or loss of cartilage that acts as a protective cushion in between bones
- As the cartilage is worn away-bone forms spurs
- Fluid filled cysts in the marrow- subchondral cysts
- Results in pain and limitation of movements
Which cells are the basis of OA?
- Chondrocytes produce interleukin-1 – initiates matrix breakdown
- Prostaglandin derivatives induces the release of lytic enzymes – prevents matrix synthesis
What are Bouchard's nodes?
- Hard, bony outgrowths or gelatinous cysts on the proximal interphalangeal joints
Seen in osteoarthritis, where they are caused by formation of calcific spurs of the articular (joint) cartilage.
- Less commonly, they may be seen rheumatoid arthritis, where nodes are caused by antibody deposition to the synovium.
What are Herberden's nodes?
DIP equivalent of Bouchard's nodes.
What is rheumatoid arthritis (RA)?
- Chronic systemic disorder-principally affecting the joints
- Producing a non suppurative proliferative synovitis- destruction of articular cartilage and ankylosis of joints
- Also affects skin, muscles, heart, lungs and blood vessels
- Women 3-5 times more than men
What are the clinical features of RA?
- Malaise, fatigue and generalised musculoskeletal pain to start of.
- Involved joints are swollen, warm,painful and stiff in the morning or after activity.
- Slow or rapid disease course and fluctuates over 4-5 years
- Small joints of the hands and feet are frequently affected-ending in a deformed joint
What is the pathogenesis of RA?
- Genetic susceptibility-65-80%- HLA- DR4 &DR1 or both
- Primary exogenous arthritogen- EBV,other viruses, Borrelia
- Autoimmune reaction within the synovial membranes- CD4 positive T-cells
- Mediators of joint damage- Cytokines-
- IL-1-6 and TNF-alpha&beta
What is the criteria for diagnosis for RA?
1. Morning stiffness
2. Arthritis in 3 or more joint areas
3. Arthritis of hand joints
4. Symmetric arthritis
5. Rheumatoid nodules
6. Serum Rheumatoid factor
4 of the above criteria
- Rheumatoid factor- present in most but not all patients, less specific
- Analysis of synovial fluid- confirms the presence of neutrophils- inflammatory picture
What are the typical radiographic changes in RA?
- changes-narrowing of joint space
- loss of articular cartilage
What non-MSK systems may be involved in RA?
- Skin-Rheumatoid nodules- commonest cutaneous manifestation, in areas of pressure
- Lung, Spleen, Heart, other viscera
Which arthroses are sero-negative?
- Ankylosing spondylitis
- Reiter’s syndrome
- Psoriatic arthritis
- Enteropathic arthritis
What is gout?
- End point of a group of disorders producing hyperuricemia
- Uric acid is the end product of purine metabolism
- Deficiency of the enzymes involved
What are the clinical features of gout?
- Chronic arthritis
- Tophi in various sites
- Gouty nephropathy
- Transient attacks of acute arthritis- crystallization of urates within and about joints, leading to chronic gouty arthritis and deposition of masses of urates in joints and other sites- tophi
What are the features pyogenic osteomyelitis?
- Systemic illness-fever, malaise, chills and marked pain over the affected region
- X-ray lytic focus of bone destruction surrounded by zone of sclerosis
- Blood cultures are positive
- Biopsy- if needed shows sheets of neutrophils
What is the aeitiology of pyogenic osteomyelitis?
- Caused by bacteria
- Hematogenous spread
- Extension from a contiguous site
- Direct implantation
What are the clinical features of infective arthritis?
- Acutely painful and swollen joints with restricted movements
- Fever, leucocytosis and elevated ESR
- Bacterial-Staphylococcus, Streptococcus, Gonococcus, Mycobacteria,
- Predisposing conditions-trauma, IV drug abuse, debilitating illness
What is osteoporosis?
- Increased porosity of the skeleton
- Reduction in bone mass
- Localised or entire skeleton
- Primary or secondary
- Primary-age and postmenopausal
What are the clinical features of osteoporosis?
- Vertebral factures
Describe osteoclast dysfunction in Paget's disease.
- Paget’s disease
- Initial osteolytic stage
- Predominant osteoblastic activity
- Burnt out osteosclerotic stage
- Net effect –gain in bone mass
- Newly formed bone is disordered and architecturally unsound
What tumours may be present in Paget's disease?
- Tumours –Benign &Malignant
- Giant cell tumour- benign tumour
- Malignant-Osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma
What are the most common symptoms in Paget's disease?
- Pain most common symptom
- Chalk stick type fractures-common
What is the aetiology of Paget's disease?
What is the histological hallmark of Paget's disease?
Is Paget's disease more common in males or females?
What is osteomalacia?
- Defects in matrix mineralization
Related to lack of Vit D
- Decreased bone density- too little bone-osteopenia
- Skeletal deformities are not seen
What is renal osteodystrophy?
Skeletal changes of chronic renal disease
- Increased osteoclastic bone resorption
- Delayed matrix mineralization
- Growth retardation
What are soft tissue tumours?
- Soft tissue-nonepithelial extraskeletal structures exclusive of supportive tissue of organs and lymphoid/hematopoietic tissue
- Fibrous tissue, adipose tissue, skeletal muscle, blood and lymphatic vasculature, peripheral nervous system.
What is the embryological origin of soft tissue tumours?
What are the features of sarcomas?
- Account for 1% of malignancies
- Congenital tumours rarely behave malignantly even with aggressive features.
- Lymph node involvement uncommon
- Blood spread to liver, lung etc.
Which syndromes are associated with
- Neurofibromatosis Type1- Neurofibroma
- Gardner syndrome-Fibromatosis
- Carney syndrome-Myxoma,melanotic schwannoma
- Turner syndrome- cystic hygroma
What diagnostic techniques are used for soft-tissue tumours?
- Ultrasound guided core biopsy
- Wide excision
- Cytogenetics- culture of fresh tissue and karyotypic analysis
- Molecular genetics- FISH and PCR and RT-PCR
What is the classification of bone tumours?
Benign bone tumours
Benign cartilage tumours
What is the most common malignant tumour?
Osteosarcomas are most common in what age group?
Young age group
What is the most common site for osteosarcoma?
Around the knee (60%)
Name malignant bone tumours other than osteosarcoma?
- Ewing’s sarcoma
- Giant cell Tumours
Which primary tumours commonly metastasise to bone?
- GI tract
What are the features of SLE?
- Butterfly rash is typical affecting the bridge of nose and the cheeks
- cardiomegaly, endocarditis
- important cause for morbidity and mortality- convulsions, hemiplegia
- 45% of patients, Nephrotic syndrome and glomerulonephritis
What is systemic sclerosis?
- Pathogenesis- complex and poorly understood
- Vessel damage, inflammatory response and cytokines
- Diffuse- widespread cutaneous lesions
- Renal, Cardiorespiratory and Gastrointestinal tract
- Osteoarticular involvement- artharlgia and arthritis
What is the localised variant of systemic sclerosis?
- Limited cutaneous involvement+ oeasophageal involvement and SI malabsorption
- CREST syndrome-Calcinosis, Raynaud’s phenomenon, oesophageal dysfunction, sclerodactyly,telangiectasia
What is polymyalgia rheumatica?
Stiffness, weakness, aching and pain in the muscles of neck, limb girdles and upper limbs.
Assoc with giant cell arteritis- affects occipital or facial arteries- pyrexia, headache and severe scalp pain
Pathogenesis- immunological mechanism suggested
What is myopathy?
Muscle disease unrelated to any disorder of innervation or neuromuscular junction
What is myositis?
Muscle fibres and overlying skin are inflamed and damaged resulting in muscle weakness
What is rhabdomyolysis?
- Destruction of skeletal muscle
- Release of muscle fibre content into blood
- Myoglobin is released into the blood stream
- Filtered through the kidney and enters urine- myoglobinuria- brown urine
What are the possible causes of rhabdomyolysis?
- Trauma, crush injuries
- Drugs- cocaine, amphetamine
- Extreme temperature
- Severe exertion-marathon running
- Lengthy surgery
- Severe dehydration
- Important complication- acute renal failure