Loco rheumatology Flashcards
Cause of excessive thoracic kyphosis
Fracture of anterior part of vertebrae
Treatment = kyphoplasty
Sheuermann’s disease
Adolescent kyphosis
Thoracic bones grow more posteriorly due to growth plate damage
Xray = Schmori’s nodes
Muscles imbalances in lumbar lordosis
Weak lower abdominals, gluteals and hamstrings
Tight psoas major and quadriceps
–> anterior pelvic tilt
Flat back syndrome
Tight hamstrings and paraspinals
Where is disc herniation most common?
L4/L5 and L5/S1 as largest vertebrae
Symptoms of cauda equina syndrome
Lower back pain Sciatica Saddle anaesthseia Bladder and bowel weakness Sexual dysfunction Lower limb weakness Reduced reflexes
Treatment of cauda equina syndrome
Laminectomy
Discectomy
Which area if most commonly affected by burst fracture?
Thoracolumbar junction
What gives bamboo spine appearance
AK
Peak age of onset of AK
20s
Which gender is affected more by AK?
Males
What HLA molecule is associated with AK?
HLA B27
Mechanisms of septic arthritis
Haematogenous spread
Disseminated osteomyelitis
Spread from adjacent soft tissues
Penetrating trauma
Septic arthritis pathogens
Most common = S. aureus
Common in middle age = gonococcus
Common in infants = staph, strep and haemophilus
Reactive arthritis pathogens
Chlamydia
Campylobacter
Salmonella
Reactive arthritis genetics
HLA B27
Mechanisms of osteomyelitis
Haematogenous spread
Spread from adjacent soft tissues
Direct trauma
Special antibiotic forms for OM
Vancomycin cement beads
Clindamycin foam
Complications of OM
Squamous cell carcinoma
Amyloidosis
Common sites of tendonitis
Lateral epicondyle
Achilles tendon
Supraspinatous
How can inflammation lead to ossification
PGE2 and COX-2 though to favour chondrocyte differentiation which can lead to ossification
How do tendons heal?
Within sheath = intrinsic from own fibroblasts
Outside sheath = from external fibroblasts
Types of enthesis
Fibrous
- for long tendons
- weaker
- Sharpey’s fibres
Fibrocartilagenous
- for short tendons that are at strong angles
- stronger
AS treatment
Sulfasalazine
Methotrexate
Anti-TNF therapies
De Quervain’s tenosynovitis
Fibrosis and narrowing of tendon sheath surrounding extensor policis bravis and abductor pollicis
Due to rubbing over radial styloid process
Trigger finger
Nodule forms on finger flexor tendon and makes extension hard
Antibodies present in SLE
ANA
Presentation of SLE
Butterfly rash
Arthralgia of small joints of hands
Photosensitivity
Renal disease
Treatment for SLE
NSAIDs Cyclophosphamide Biologicals against B and T cells Steroids IV immunoglobulins
Gout pathophysiology
Purines –> uric acid
Uric acid normally insoluble or coated in apo E and B so inert
If levels rise too much –> crystals form and trigger immune reaction
Phagocytes engulf crystals –> lysis
Release of enzymes and acid content
Gout causes
Overproduction - excessive meat, beer, red wine, shellfish intake - tumour lysis syndrome - Lesch-Nyhan syndrome Under-excretion - diuretics - renal insufficiency - dehydration
Common locations for tophi
Ear cartilage Toes and fingers Olecranon bursa Achilles tendon Kidney
Histology of tophi
Fibrous tissue
Ring of foreign body giant macrophages
Ring of lymphocytes
Normal uric acid level
<6.8mg/dL
Crystals in gout
Monosodium urate
Needle shaped
Strong negative birefringence
X-ray in gout
Rat bite erosions
Soft tissue swelling
Gout treatment for acute attacks
Analgesics
Calchicine = anti-mitotic to prevent neutrophil proliferation
Corticosteroids
Anti-IL-1 biologicals = anakinra, rilonacept, canakinumab
Chronic gout treatment
Xanthine oxidase inhibitors = allopurinol, oxypurinol, febuxostat
Probenecid = increases uric acid secretion (urisuric)
Rasburicase = uric acid –> allantoin (inert)
Other urosurics = vitamin C, losartan
Crystals in pseudogout
Calcium pyrophosphate
Rhomboid shaped
Weak positive birefringence
X-ray of pseudogout
Calcification of soft tissues
Especially menisci of the knees and wrists
Nodes in OA
DIP = Herberden's PIP = Bouchard's
Joints affected in nodal generalised OA
DIP and PIP 1st CMC Hallux valgus (1st MTP) Hallux rigidus (1st MTP) Knee
Apatite associated destructive arthritis
Due to hydroxyapatite crystals in joint space
Can cause severe joint erosions
Mainly affects hip and shoulder (Milwaukee shoulder)
Erosive OA
Cartilage destruction + synovial inflammation
Affects DIP, PIP and 1st CMC
Gull wings appearance from central erosions
Ankylosis common
OA of premature onset causes
Previous meniscectomy
Perthes
Haemochromatosis
Rate of bone loss
After 40 = 0.7% per year
After menopause = 2-9% per year
T scores
> -1 = normal
-1 to -2.5 = osteopenia
< -2.5 = osteoporosis
Causes of secondary osteoporosis
Steroids Anorexia Chronic malabsorption diseases Malignancy Thyrotoxicosis Hypogonadism
Too much Th1
Autoimmunity
Too much Th2
Allergy
Too much Th17
Chronic inflammation
Too much Treg
Cancer
Too little Treg
Autoimmunity and inflammation
Eye problems in RA
Keratoconjunctivitis sicca = dry eyes
Scleritis
Scleromalacia perforans
Complications of RA
Carpal tunnel AAS Osteoporosis Pericarditis Pleuritis
Signs of scleroderma
Thickened waxy appearance of skin
Digital ischaemia
Signs of dermatomyositis
Purple rash on eyelids, backs of hands, chest, neck, back
Proximal muscle weakening
Signs of reactive arthritis
Conjuntivitis
Skin rash
Sausage toe
Arthritis
Paget’s disease phases
Increased rate of resorption = large numbers of osteoclasts break down bone
Compensatory phase = osteoblasts produce large amounts of disorganised bone
Sclerotic = left with hyper cellular bone with hyper vascular bone marrow
Which bones are affected in Paget’s?
Pelvis
Femur
Skull
Vertebrae
Complication of Paget’s disease?
Osteosarcoma
Paget’s treatment
Bisphosphonates = slow resorption
Calcitonin = inhibits osteoclasts
Calcium and vitamin D
Sclerostin mAb
Romosozumab
How many fibres in a motor unit?
5-200
Which muscle fibres appear darker with ATPase staining?
Type 2 fast fibres
Antibody in dermatomyositis
ANA
Anti-Jo1
EMG in myositis
Low grade irritability
Fibrillations
Early recruitment and low amplitude
Biopsy of myositis
Variation in fibre size with central nuclei Necrosis Inflammatory cell infiltration - mainly connective tissue - mainly CD8 T cells
Polymyositis vs dermatomyositis
Polymyositis = endomysium Dermatomyositis = perimysium
Treatment for dermatomyositis
Azathioprine
Methotrexate
Rituximab
Infliximab
What causes death in dermatomyositis
Malignancy
Pulmonary fibrosis
Inclusion body myositis muscles affected
Quads
Wrist flexors
Oesophagus
Biopsy of inclusion body myositis
Fibres contain empty vacuoles
Stain for beta amyloid
Variation in fibre size
Central nuclei
Genetics of DMD
X linked recessive
Presentation of DMD
Proximal muscle weakness
Unable to walk by age 7
Causes of death in DMD
Respiratory failure due to diaphragm damage
Dilated cardiomyopathy
Biopsy of DMD
Fibre size variability Splitting of muscle fibres Large fibres with central nuclei Endomysial fibrosis Muscle tissue gradually replaced by fibrous and adipose tissue in late stages
Pathophysiology of DMD
Absence of dystrophin needed to link muscle membrane and sarcomeric proteins
What does excessive corticosteroid use do to muscle fibres?
Degeneration of type 2 dark fibres
What does excessive statin use do to muscle fibres?
Rhabdomyolysis
Myoglobin release can cause kidney problems
What is elevated in DMD?
Creatine kinase
What is raised in myositis?
Creatine kinase
What does excessive alcohol intake do to muscle fibres?
Type 2 fibre loss
Acute session = rhabdomyolysis
Chronic = proximal weakness
Antibodies in fibromyalgia
Antipolymer
Articular cartilage layers
Top = tangential Middle = transitional Deep = radial
Gene that increases OA risk
HMGB2
Usually expressed in superficial zone to protect cells
3 macroscopic changes in OA
Fibrillation
Cracking
Eburnation
Microscopic changes in OA
Chondrocyte necrosis Isogenic clusters of chondrocytes remaining Hyaline --> fibrocartilage Type II --> I collagen Duplicated tidemark
Neutraceuticals for OA
Chondroitin sulphate
Glucosamine
Capsaicin
Topical chill for analgesia
Microfracture vs chondrocyte graft
Microfracture –> fibrocartilage
Chondrocyte graft –> hyaline cartilage
Where to perform osteotomy for varus deformity
Tibia
Types of synoviocytes
A = macrophages B = fibroblasts
Distance between joint surfaces
50um
Volume of synovial fluid in knee
1-2ml
String test
Should be 4-6cm
Mucin clot test
Add 2-5% acetic acid
Should form solid clot
Finkelstein’s test
De Quervains tenosynovitis
When to avoid joint injection
Olecranon bursitis –> infection
Achilles tendon –> rupture
When do you inject directly into the enthesis?
Tennis elbow
Which movements are limited in frozen shoulder?
External rotation > internal rotation > abduction
Tests for impingement
Painful arc = pain most at 90 degrees abduction
Painful resisted abduction
