Muscle, tendon, bursae, ligament pathologies Flashcards
What is the role of acetylcholine at the neuromuscular junction?
- Action potential reaches NMJ, causing ACh release into synapse
- it binds to nicotinic receptors on motor end plate, causing release of Na into muscle fibre
What is the role of AChE at the NMJ?
- one of the key functional proteins of NMJ
- does fast hydrolysis of ACh after its binding to postsynaptic receptors
What are the acquired disorders of muscle, tendon, lig, bursae?
- Muscle, tendon, lig, bursa injury
- Fibromyalgia
- Myofascial pain syndrome
- Chronic fatigue syndrome
- NMJ disorders
- Acquired myopathy
- Neoplasms
What are the congenital disorders of muscle, tendon, lig, bursae?
- Muscular dystrophies
- Spinal muscular atrophy
- Familial periodic paralysis
What is exercise induced muscle injury?
- physiological response (NOT PATHOLOGICAL) -lactic acid buildup
- DOMS
- 24-48hrs after unaccustomed intense exercise, eccentric, viral infections
- Muscle cell damage -> breakdown -> inflammatory response
What may be a complication of exercise induced muscle injury?
acute compartment syndrome
What is an intermuscular haematoma?
- occur near inter muscular septa or fascial sheaths
- facilitates tracking of haematoma with gravity to distal limb
- early dispersal, minimise inflammatory response (and scarring)
- early resolution
What is an intramuscular haematoma?
- occur secondary to muscle damage
- 2-3x longer recovery
- confined, palpable mass
- greater inflammatory response, scarring, risk for compartment syndrome myositis ossificans
Which degree muscle strain has the most pain?
2nd degree
-because when there is complete tear, it canot pull at the remaining strands when activated
Which degree muscle strain has a defect?
only 3rd degree
What causes a 1st degree muscle strain?
- sudden overstretch
- sudden contraction
- decelerating limb
- insufficient warm up
- lack of flexibility
What are the recovery times for each degree muscle strain?
1st: 2-21 days
2nd: 20-90 days
3rd: 50-180 days
What is an Acute lumbar strain?
- strain of spinal muscles
- macro or microtrauma (repetitive lifting, bending, twisting)
- pain, tenderness, spasm, swelling, stiffness
- passive/active lengthening and active shortening cause pain
- passive shortening relieves
What is chronic recurrent lumbar strain?
- repeated episodes of partial tears
- prolonged Hx of recurrences
- failure to address the causes of acute strains
- changes in surrounding tissue (myofascial pain syndrome)
What degree muscle strain has the most lost ROM?
2nd degree has some lost ROM
3rd degree has only lost active ROM
What is myoglobinuria?
another name for rhabdomyolysis
What is rhabdomyolysis?
- group of disorders of muscle damage
- release of myoglobin -> excreted in urine (damages kidneys)
- causes pain, stiffness, weakness, fatigue, tenderness, red-brown urine
What are the causes of rhabdomyolysis?
- truma
- heat stroke
- ischaemia to limb
- overexertion
- genetic
- drugs, toxins, electrolyte disturbance
- thyroid disorder
- diabetic ketoacidosis
- snake bites
What are the complications of rhabdomyolysis?
- muscle damage
- renal failure
- seizures
- cardiac arrhythmias
- shock
- death
What is the pathophysiology of rhabdomyolysis?
trauma -> break in cell wall -> Na+ and H2O into cell -> lysis (some contents damage neighbouring cells) -> myoglobin, K+, phosphorus, uric acid into blood stream
What is the pathophysiology of seizures in rhabdomyolysis?
electrolyte disturbance from broken cells
What is the pathophysiology behind renal failure in rhabdomyolysis?
high amounts of myoglobin in the blood stream from broken cells
What is the pathophysiology behind cardiac arrhythmias in rhabdomyolysis?
K+ in the blood stream from broken cells
How can rhabdomyolysis be fatal?
Can lead to crush syndrome
• renal failure (myoglobin)
• hypervolemic shock (metabolic acidosis from uric acid)
• cardiac arrhythmia (potassium)
• disseminated intravascular coagulation (happens when you have massive bleed and body trying to stop it)
What is myositis ossifians?
- possible late complication of localized muscle injury
- scar tissue -> calcify -> ossify
- ex. equestrians thigh adductors
Compare sprain and strain?
Sprain:
• tear in ligament or capsule
• pain on end ROM and passive ROM
Strain:
• painful active ROM
Both:
• overstretch injury
Which degree sprain is most painful?
2nd degree
How does testing passive ROM tell us if it is a sprain or strain?
passive ROM increases in motion from 1st - 3rd degree sprain
What are the clinical presentations of sprains?
Varying degrees of: • pain • rapid swelling • heat • discolouration • limited function and stability • local tenderness
What are common sites of sprains?
- ankle (lateral side)
- knee (collateral ligs and ant. cruciate)
- elbow (ulnar side)
How long does healing take for healing of a third degree sprain?
3-6 weeks
What are the implications of a second degree sprain?
- tendency for recurrence
- needs modified immobilisation
- may stretch out further with time
What are the implications of a third degree sprain?
- needs prolonged protection
- surgery maybe
- often permanent functional instability
What are causes of tendonitis?
- repetitive stress to tendon
- ageing
- acute trauma
- deposition of crystals
- hyper mobility of joint
- vascular interference
- postural malalignment
- use of fluoroquinolone (antibiotic)
What is the pathophysiology of tendonitis?
- inflammation -> vascular disruption -> degenerative changes
- tendon thickens -> limits movement
- more oedema or calcifications
What are some common examples of tendonitis?
- lateral epicondylitis (tennis)
- medial epicondylitis (golfer)
- rotator cuff tendinopathy
- bicipital
- patella tendon (jumpers knee)
- popliteus tendon
- ITB syndrome
- shin splints
- achilles tendinopathy
What are clinical features of tendonitis
- varying degrees of pain
- tenderness
- limitation of movement
What are causes of bursitis?
- repetitive activities
- overuse
- excessive pressure (kneeling, tight shoes, leaning on elbow)
- acute trauma
- pre-existing joint disease
- autoimmune disorders
- crystals deposition
- infections
- obesity
What is the pathophysiology of bursitis?
increase in vascularity of bursal sac -> oedema -> spread to adjacent tissues
What are some common examples of bursitis?
- housemaid’s knee (pre-patellar)
- calcaneal
- trochanteric
- weavers bottom (ischiogluteal)
- sub-acromal
- olecranon
What are the clinical features of bursitis?
pain, swelling, tenderness, red
What is a central sensitivity syndrome?
- group of syndromes with abnormality in the processing of pain by the CNS
- development and maintenance of chronic pain
- wind-up -> regulated in persistent state of high reactivity
- hyperalgesia or allodynia
What is the definition of fibromyalgia?
syndrome characterized by widespread pain and constitutional manifestations (fatigue, cognitive impairment)
What is the aetiology of fibromyalgia?
- abnormal processing of pain by CNS
- co-exists with systemic inflammation (SLE, RA, polymyalgia rheumatic)
- biochemical, metabolic and immune regulation disturbances
What are the symptoms of fibromyalgia?
- aching, stiff multiple muscle groups
- up to 40 tender points in consistant locations
- pins, stabbing, numbness
- severe joint pain, headaches, swelling
- transient pain, fluctuating
- maybe also chronic fatigue, depression, cognitive & sleep issues
What is the difference between tender point and trigger point?
Tender:
• well defined, located at musculo-tendinous junction
• do not refer
Trigger:
• refer pain to specific area following stimulus
What are some common sites of trigger points?
- trapezius
- epicondyles
- attach. of elevator scap
- post. iliac crest
- SCM
What are the signs of fibromyalgia?
- joint & muscle tenderness
- joint laxity
- (rare) swelling, warm, red joint
What is the diagnostic criteria for fibromyalgia?
Meet 3 conditions:
• WPI > 7 + SS scale score >5 or WPI 3-6 + SS scale score >9
• > 3 months
• not other disorder explaining this
What is the WPI for fibromyalgia diagnosis?
- Widespread pain index
- number of area patient has had pain over the last week
- score 0-19
What is the SS scale score for fibromyalgia diagnosis?
- Symptom severity scale score
- severity of Fatigue, waking unrefreshed, cognitive symptoms (0-3)
- plus severity of somatic symptoms in general (headache, IBS, depression..etc)
What is the theorized pathophysiology of fibromyalgia?
pre-existing factors (serotonin receptors, endorphins) + precipitating factors (muscle microtrauma, dekconditioning, sleep disturbance) –> Pain, fatigue, depression manifested by skin hyperactivity + muscle contraction and deconditioning –> + cutaneous nociception, + muscle nociception –> spinal cord and cortex –> + sympathetic outflow (positive feedback loop)
What is myofascial pain syndrome?
- recurrent or chronic pain, located in 1 or more muscles
- very common
- pain more localized than fibromyalgia
What are the clinical features of myofascial pain syndrome?
- tight, tender muscles, limited ROM
- weak (no atrophy)
- autonomic symptoms
- Local twitch response
- trigger points
What is the cause of myofascial pain syndrome?
- uncertain
- latent TrPs activated by muscle tension, poor posture, psychological stress
- dysfunction of motor endplates
What is the definition of chronic fatigue syndrome?
medically unexplained severe fatigue that persists or relapses for 6 months, associated with >4 or 8 distinctive physical symptoms
What are the distinctive physical symptoms of chronic fatigue syndrome?
- impaired memory/ concentration
- recurrent sore throat
- tender cervical or axillary lymph nodes
- mild muscle pain
- arthralgia
- new headache types
- sleep not refreshing
- post-exertional malaise
What is idiopathic chronic fatigue?
Severe fatigue but does not meet the diagnostic criteria for chronic fatigue syndrome
What are the exclusion criteria for chronic fatigue syndrome?
1) Active medical condition:
• hypothyroidism
• sleep apnoea, narcolepsy
• effects of medication
2) Previous condition not completely resolved:
• previous malignancy
• hep B or C
3) Major depressive disorder with psychotic or melancholic features • bipolar affective disorder • schizophrenia, delusional disorders • dementias • anorexia or bulimia nervosa
4) Alcohol/ substance abuse within 2 years
5) Severe obesity (BMI>45)
What is the aetiology of chronic fatigue syndrome?
Infectious agents
• chronic mycoplasma infections perpetuate and trigger
• viruses/bacteria (B.burgdorferi) trigger
Immunological factors
• perpetuate and pathogenesis
Neuroendocrine factors
• down-regulation of HPA-axis, disturbance of ANS, neuroendocrine dysfunction cause hyperalgesia and perpetuate and pathogenesis
Psychiatric factors
• pathogenesis and perpetuation
Describe the chronic fatigue syndrome paradox?
- current CDC definition states CFD is only when no other causes exist
- but may be caused by infectious agent
Must either:
• narrow the definition
• broaden the definition
Which is the most common neuromuscular junction disorder?
Myasthaenia Gravis
What is the relationship between rhabdomyolysis, crush syndrome and compartment syndrome?
- Rhabdomyolysis is a pathological process
- crush and compartment syndromes are severe forms of rhabdomyolysis
- in both cases: pressure builds up, squeezes arteries (less nourishment to muscle and nerves)
What is compartment syndrome?
- rhabdomyolysis localized in one fascial compartment
- caused by trauma (haematoma, insect bite), oedema (frostbite, burn, overuse)
- pain, parasthesia, passive stretch pain, tender, pulseless
What is crush syndrome?
- rhabdomyolysis of many large muscles
- toxins accumulate in the body
- risk of repercussion injury (when crushing item is suddenly removed, toxins flood whole body)
- shock, pulseless, pale, absence of pain
What is the function of a bursa?
- fluid filled sack
- located where muscles and tendons move over bony joint areas
- reduce friction caused by tendons moving against skin and bones
What is housemaid’s knee?
- pre-patellar bursitis
- knee pain,
- knee swelling, tenderness, red, limited movement from pain
- relieve of pain with rest
What is allodynia?
perception of pain with non-pain stimulus
What is hyperalgesia?
disproportional amount of pain from pain stimulus
What are the pros and cons of using the ICD10 diagnostic criteria for fibromyalgia?
Advantages:
• gives patient a diagnosis
• excludes worry about other conditions
Disadvantages:
• all subjective, depends on patient’s awareness of their symptoms, how long
• pain may fluctuate on and off
• not just one test to rule it out
How does myofascial pain syndrome differ from fibromyalgia?
MPS • localised • trigger points Fibro • widespread • tenderpoints • plus fatigue, cognitive, functional issues • comorbidities (depression)
What is myasthenia gravis? (definition, age, sex, occurence)
disorder of episodes of muscle weakness
• occurs 20-40yrs
• males
• rare, 1/100 000 incidence
What is the aetiology of myasthenia gravis?
- autoimmune
- antibodies to ACh receptors destroy receptors or prevent binding
- associated with other autoimmune diseases (RA, SLE, thyroiditis
- thymus gland issues
What are the clinical features of myasthenia gravis?
- double vision
- ptosis
- Difficulties: chewing, speaking
- fatigue quickly
- deep tendon reflex normal on first test
- no sensory deficits
- ice delays fatigue
- symptoms worsen over time
- 20-30% resolve
What is ptosis?
weakness of eye opening
What are myopathies?
Diseased function of muscle FIBRE only
• inherited or acquired
What are the aetiologies of inherited and acquired myopathies?
Inherited
• dystrophies
• congenital
Acquired • idiopathic (immune connective tissue disorder) • drugs (steroids) • excessive alchohol • endocrine (thyroid) • electrolyte (K+) • acude periodic paralysis • infections
What is infections myositis?
Acquired myopathy from infection • tosoplasmosis • coxsackie virus • HIV • influenza • Lyme disease • staph aureus • parasites • fungi
What are the clinical features of myopathies?
- muscle weakness (usually symmetrical, proximal)
- fatigue and malaise
- NO sensory changes
- atrophy and hyporeflexia -late findings
What are the tumours derived from skeletal muscles?
Rhabdomyoma
Rhabdomyosarcoma
both rare
What is a rhabdomyoma?
- benign tumour from skeletal muscle
* found in tongue, uvula, larynx, nasal cavity, axilla, heart and neck muscles
What is a rhabdomyosarcoma?
- malignant tumour from skeletal muscle
- rapidly metastasize
- found in head, neck, genitourinary track
What is sarcoidosis? (definition, sites, age, sex)
- non-caveating granulomas
- affects many body tissues
- mostly young adults
- chronic or acute
- aetiology unknown
- equal in sexes
- 20-40yrs
- africans and Scandinavians
What disorder pathologically most closely resembles sarcoidosis?
TB
• except no evidence of caseous necrosis or mycobacterium
What are the clinical features of sarcoidosis?
- often mild (incidental finding on chest x-ray)
- fever, persistent cough, anorexia, weight loss
- lymphadenopathy, hepatosplenomegaly
- iritis, uveitis
- skin rash
What is the difference in resolution in acute vs chronic sarcoidosis?
Acute:
• high spontaneous rate of remission
• fever, arthralgia
• erythema nodosum of tibia
Chronic: • bone lesions • skin lesions • swelling, deformity of hands and feet • >40yrs • debilitating, often fatal systemic fibrosis (lungs)
What is a muscular dystrophy?
- group of inherited myopathies
* progressive muscle degeneration and regeneration
What is the difference between myopathy, myositis and muscular dystrophy?
Myopathy: disease of muscle fibre
Myositis: inflammation of muscle
Dystrophy: inherited myopathy from breakdown of skeletal muscle
What is Duchenne’s muscular dystrophy?
- 1/3500 males
- recessive gene carved by mothers
- diagnosed at 3-5yrs
- can’t walk, clumsy
- mild mental retardation
- contracture of calfs, weak toes
- muscles fill with fat
- increased lordosis
- Gower’s sign
- decreased deep tendon reflexes
- heart tissue issues causes death at 20yrs
What is Becker’s muscular dystrophy?
- similar to Duchenne’s but later onset (10-15yrs)
- recessive gene
- live till 50-60yrs, walk until 40yrs
- begins as muscle cramps
- calf hypertrophy, limb girdle muscles
- NO mental retardation
What is pseudohypertrophic muscular dystrophy?
another name for Duchenne’s muscular dystrophy
Which is the most common form of muscular dystrophy?
Duchenne’s MD
Which is the most severe form of muscular dystrophy?
Duchenne’s MD
What is Autosomal dominant muscular dystrophy?
- affects face, shoulders, arms in that order
- 1-2/100 000 incidence
- onset 20yrs
- familial
- scap winging, camel-back, buttock protrusion
- increased lordosis
- decreased deep tendon reflexes
What is Facio-scapulo-humeral dystrophy?
another name for Autosomal dominant dystrophy
What is scapuloperoneal muscular dystrophy?
- benign
- distal lower legs, proximal upper arms
- foot drop at 20-30yrs
- deltoid, triceps, biceps next
- decreased deep tendon reflexes
What is Myotonic dystrophy?
- multisystem
- myotonia
- autosomal dominant
- 5/100 000 incidence
- 10-50yrs
- instability of Na and Cl channels in muscle membrane
- thenar eminence
- atrophy of cheeks, SCM
- frontal baldness, testicular atrophy, cataracts
- dysphagia
- distal forearm and leg muscles
- arrhythmia -> heart attack
- 30% milf hypothyroidism
What is myotonia?
failure of immediate muscle relaxation after voluntary contraction has stopped
What is Limb girdle muscular dystrophy?
- slow progressive, benign (not terminal)
- teens-20s
- pelvic girdle first, asymmetrical
- little disability
- male = fem
What is spinal muscular atrophy?
- degeneration of ventral horns of spinal cord
- autosomal recessive
- progressive skeletal muscle trophy
- hypotonia
- muscle weakness and fatigue
Is spinal muscular atrophy a muscular dystrophy?
no
it is a neuromuscular disease
What are the common muscular dystrophies?
- Duchennes
- Beckers
- Autosomal dominant
- Scapuloperoneal
- Myotonic
- Limb-girdle
What is familial periodic paralysis?
- autosomal dominant
- episodes of hypokalaemia
- precipitated by high carbohydrate diet or resting following exercise
- common at night or on waking
What are the aetiologies of 3rd degree strain?
- previous muscle injury
- collagen disease
- abuse of anabolic steroids
Compare Tietze’s syndrome vs Costochondritis?
Tietze’s: sternum + cartilage + rib
Costochondritis: cartilage + rib
