Musculoskeletal Flashcards
Mechanism of SMOOTH MUSCLE contraction
Depolarisation caused by action potential and OPENING of voltage gated Ca2+ channel
Ca2+ ions bind to CALMODULIN
Myosin light kinase chain ACTIVATED
The role of myosin:actin coupled with MYOSIN P causes contraction
Mechanism of SKELETAL and CARDIAC MUSCLE contraction
Depolarisation caused by action potential and OPENING of voltage gated Ca2+ channel
- NEUROTRANSMITTER released
Spread of depolarisation down the T TUBULES to DIHYDROPYRIDINE RECEPTORS in skeletal muscle
In CARDIAC muscle- it involves calcium-induced calcium release
- Increased calcium ions from calcium-induced calcium release- calcium ions bind to TROPONIN C
Myosin head binds to actin when TROPOMYOSIN moves
Cause of Rheumatoid Arthritis
Hypersensitivity III reaction
Involves HLA DR4 and HLA DR1
6 Hand signs of Rheumatoid Arthritis
- Z deformity
- Boutonniere deformity
- Swan neck deformity
- Ulnar deviation
- Subluxation of fingers
- Raynaud’s phenomenon (decreased blood flow to fingers and sometimes ears, nose, nipples, toes, knees)
Feet and Skin signs of Rheumatoid Arthritis
Feet-
- Hammer toe deformity
- Subluxation of toes
Skin-
- Rheumatoid nodule
- Vasculitis
Respiratory, Cardiovascular and Wrist signs of Rheumatoid Arthritis
Respiratory-
- Pulmonary Fibrosis
Cardiovascular-
- Atherosclerosis increased in RA
Wrist-
- Carpal Tunnel syndrome
Investigations in Rheumatoid Arthritis
Blood-
- Rheumatoid factor
- Cyclic Cytrullinated Peptides (CCP) antibodies
Radiology-
- Subluxation
- Periarticular osteoporosis
- Bony erosion
Treatment of Rheumatoid Arthritis
Physiotherapy
Medical-
- GLUCOCORTOIDS
- DMARDS (Gold salts, Methotrexate, Sulfasalazine)
- Anticytokine therapy considered if patient is intolerant to METHOTREXATE
Surgery- if severely affected- EXCISION arthroplasty
Complications of Rheumatoid Arthritis
PERICARDITIS
Sjogren’s Syndrome (dry eyes and mouth)
Cervical myopathy
Pain worse in the morning vs in the night
Morning- Rheumatoid Arthritis
Night- Osteoarthritis
Risk factors of Osteoarthritis
- Increased age
- Conditions such as Haemochromatosis and Ehlers-Dalos Syndrome
- Obesity
- Trauma to joint
Signs and Symptoms of Osteoarthritis
- Pain and stiffness
- Swelling around joints
- Crepitus (crackles)
- HEBERDEEN’s nodes at DIP (remember outer hebrides)
- BOUCHARD’s nodes at PIP
Investigations in Osteoarthritis
Bloods- relevant is OS is linked to another condition such as HAEMOCHROMATOSIS
Radiology (LOSS)
- Loss of joint space
- Osteophytes
- Subchondrial cysts
- Sclerosis
Treatment of Osteoarthritis
Encourage exercise and weight loss
Medical-
- Analgesia (paracetamol or NSAIDs)
- Gels such as CAPSAICIN
- Steroidal injections
Complications of Osteoarthritis
- Increased risk of GOUT
- CHONDROCALCINOSIS (calcium phosphate deposition in joints)
Types of Spondyloarthropathies
Psoriatic arthritis
Enteropathic arthropathies
Ankylosing spondylitis
Reactive arthritis
Reactive arthritis symmetrical or asymmetrical and causes of it
ASYMMETRICAL
Occurs after GASTROINTESTINAL or UROGENITAL infection
4 signs and symptoms of Reactive arthritis
Urethritis
Uveitis- eye infection
Conjuctivitis- eye infection
Arthritis- pain and stiffness
Investigations in Reactive arthritis
Make sure it is SERONEGATIVE for Rheumatoid arthritis
Blood cultures- look for infectious cause
Treatment of Reactive arthritis
Physiotherapy
Analgesia (NSAIDs)
DMARDs (sulphasalazine)
Complications of Reactive arthritis
Arrhythmia
Aortic insufficiency
Psoriatic arthritis, Enteropathic arthritis and Ankylosing spondylitis associated with which gene?
HLA B27
Causes of Psoriatic arthritis
Inflammatory process coupled with HLA B27 gene
THREE signs and symptoms of Psoriatic arthritis
+3 points about psoriasis
(+4 nail changes)
Psoriasis-
- Salmon pink plaques with evidence of scaling
- usually present on the EXTENSOR SURFACES but can occur in RAINDROP PATTERN over torso
- GUTTATE PSORIASIS preceded by UPPER RESP INFECTION caused by STREPTOCOCCUS
Nail changes (pitting, yellowing of nail, onycholysis (painless detachment of nail from nail bed), subungual hyperkeratosis (scaling under skin))
Swelling of affected joint and swelling of affected joints
Investigations in Psoriatic arthritis
Make sure bloods are seronegative for RHEUMATOID ARTHRITIS
Radiology-
- pencil-in-cup deformity on hand xray
Treatment for Psoriatic arthritis and Ankylosing spondylitis
Explain that Psoriasis has NO CURE
ANALGESIA (NSAIDs)
DMARDS (Methotrexate)
Where does chronic inflammation happen in Ankylosing Spondylitis
Spine and Sacroiliac joints
Signs and symptoms of Ankylosing spondylitis
Question mark posture
Bamboo spine- due to CALCIFICATION OF LIGAMENTS
Pain and stiffness which gets BETTER with EXERCISE
Enteropathic arthritis associated with which condition?
IBD
4 Signs and Symptoms of Enteropathic arthritis
IBD symptoms
Spondylitis (inflammation of spine)
Sacroilitis
Peripheral Arthritis (usually of large joints)
Which joint does Gout present in? and what is deposited?
Metatarsophalangeal joint
URATE crystals
Causes of GOUT
Horrific DELAY
Hyperuricaemia, Hereditary
Diuretics (thiazide) Ethanol Leukemia renAl impairment lesch-nYhan syndrome
Signs and Symptoms of GOUT
inflammation of affected joint
Tophi (urate deposits) may be present on tendon surfaces (elbow or ear)
Patient may have symptoms of RENAL CALCULI
Investigations in GOUT
Serum URATE levels
CREATININE
GFR- assess kidney function
SYNOVIAL FLUID ANALYSIS (positive if birefringement monosodium urate crystals seen)
Treatment of GOUT
Low PURINE diet
Stop causative agents- thiazide diuretics
ANALGESIA
Acute- COLCHICINE and STEROIDS
Chronic- ALLOPURINOL and FEBUXOSTAT may be used if allopurinol is not tolerated
Complications of GOUT
Renal calculi
Tophi formation
Risk factors of OSTEOPOROSIS
- Prolonged STEROID use
- Diet deficient in CALCIUM
- Increasing age
- Excessing alcohol and smoking
- Loss of protective oestrogen in postmenopausal women
- Endocrine disorders such as DIABETES MELLITUS and HYPERTHYROIDISM
Signs and Symptoms of OSTEOPOROSIS
- often asymptomatic until pathological fracture
- Loss in height
- Back pain
- Dowager’s hump (hyperkyphosis)
Investigations in OSTEOPOROSIS
PTH
Serum calcium
Serum phosphatase
Alkaline phosphatase
DEXA scan- T score>2.5 is diagnostic
Treatment of OSTEOPOROSIS
Selective Oestrogen Receptor Modulators (SORM/ SERM)
Calcitonin and Bisphosphonates
The ONLY BONE DISEASE where Serum Calcium and Serum Phosphate are low
And PTH is high
Osteomalacia
Two bone diseases where Alkaline Phosphatase is high
Osteomalacia and Osteopetriosis
Axillary Nerve NERVE ORIGIN
C5-C6
Musculocutaneous NERVE ORIGIN
C5-C7
Median NERVE ORIGIN
C5-T1
Ulnar NERVE ORIGIN
C8-T1
Radial NERVE ORIGIN
C5-C8
Axillary nerve LESION
Deltoid muscle paralysis
Musculocutaneous LESION (rare)
Paralysis of biceps, brachialis and coracobrachialis
4 LESIONS of Median nerve
Above antecubital fossa
At wrist
Below antecubital fossa
Within the wrist
Ulnar LESION
Ulnar clawing
Radial LESION
Wrist drop
C5-C6 LESION
Erb-Duchenne Palsy
C8 and T1 LESION
Klumpke’s Palsy
Two causes of Deltoid muscle paralysis (AXILARY LESION)
Shoulder dislocation
Humerus neck fracture
Two causes of Paralysis of biceps, brachialis and coracobrachialis (MUSCULOCUTANEOUS LESION)
Complication of surgery
Dislocation
Complication of Musculocutaneous lesion
DECREASED sensation of lateral forearm
TWO causes of LESION above antecubital fossa (MEDIAN LESION)
Supracondylar fractures
Neuropathy
Cause of LESION at wrist (MEDIAN LESION)
LACERATION of wrist
3 complication of LESION above antecubital fossa AND at the wrist
Papal sign of benediction
Ape hand deformity
Loss of sensation over THENAR EMINENCE
Cause of LESION below antecubital fossa (MEDIAN LESION)
Injury to the ANTERIOR interosseous branch of the MEDIAN NERVE
Two complications of LESION below antecubital fossa
Anterior interosseous syndrome
Inability to PRONATE the forearm
Cause of LESION within the wrist (MEDIAN LESION)
Carpal Tunnel Syndrome
Carpal Tunnel Syndrome-
Where is the PARAESTHESIA?
When is the pain worse?
What tests are done to diagnose Carpal Tunnel Syndrome?
What 7 things is Carpal Tunnel Syndrome associated with?
- Paraesthesia in LATERAL 2.5 fingers
- Pain is worse at night (like OSTEOARTHRITIS)
- Phalen’s and Tinel’s Test done to diagnose Carpal Tunnel Syndrome
- Pregnancy
- Oral Contraceptive Pill
- Diabetes
- Rheumatoid arthritis
- Heart failure
- GOUT
- ACROMEGALY
2 causes of Ulnar clawing (ULNAR LESION)
Cubital Tunnel Syndrome
Ganglion cyst in the Guyon canal
What is the Ulnar paradox?
Ulnar clawing is more PRONOUNCED, the more DISTAL the lesion
Erb-Duchenne Palsy (C5 and C6 lesions) and Klumpke’s Palsy (C8 and T1 lesions) are both caused by what?
DYSTOCIA (difficult childbirth)
2 causes of Wrist drop (RADIAL LESION)
Trauma: fracture of the HUMERUS
Lead poisoning
What four things are seen in C5 and C6 LESIONS?
Paralysis of infraspinatus, teres minor
Paralysis of supraspinatus, deltoid
Paralysis of biceps
Paralysis of brachialis