Musculoskeletal / Orthopedic Flashcards
valgus stress test (knee)
abnormality in what condition?
outward pressure on medial leg with a fixed femur
if MCL is injured, pt will show excessive knee joint widening on valgus stress
(MCL protects against valgus stress + excess external tibial rotation)
serratus anterior
functions (origin, insertion)
facilitates arm elevation by pulling lower end of scapula forward
helps with respiration by lifting ribs when shoulder girdle is fixed
(ribs 1-8 to medial scapular border)
Conditions associated with Carpal Tunnel Syndrome (5)
Pregnancy - fluid accumulation
RA - tendon inflammation
Hypothyroidism - GAG buildup
Diabetes Mellitus - CT thickening
Long-Term Dialysis - dialysis-associated amyloidosis > buildup of beta2-microglobulin
Signs + sx in carpal tunnel
1 symptom group, 3 signs
Median nerve distribution pain/paresthesia/sensory impairment (lateral 3.5 digits palmar surface)
motor weakness of thumb abduction/opposition with THENAR ATROPHY
Tinel sign - tapping flexor surface of wrist invokes sx
Phalen sign - flexion of wrist invokes sx
Ankylosing Spondylitis
S/S
(msk issues plus 3 extraskeletal issues)
Low back pain - onset slow + <40 yrs; improves with exercise; worse at night; also HIP + BUTT pain
Enthesitis - where tendon meets bone
Systemic - fever, chills, fatigue, weight loss
- Limited chest wall expansion - causes hypoventilation; must monitor!
- Acute anterior uveitis - unilateral pain, photophobia and blurry vision
- Ascending aortitis - dilation with aortic insufficiency
Friederich Ataxia
inheritance + gene? Musculoskeletal issues? Other issues (3)?
AR mutation of frataxin (FXN) - increased GAA repeats > decreased expression of mitochondrial protein for iron-sulfur enzyme assembly > decreased energy production + increased oxidative stress
Spinocerebellar and lateral corticospinal degeneration - gait ataxia + spastic weakness
Kyphoscoliosis + high plantar arches (pes cavus)
Dorsal column/DRG degeneration - position/vibration loss
Heart - HCM and CHF
Diabetes Mellitus - in 10%
Charcot-Marie-Tooth disease
inheritance? pathogenesis? s/s?
differential?
AD - demyelination of peripheral nerves via a mutated myelin protein gene
distal leg weakness/atrophy + sensory deficits
kyphoscoliosis + high plantar arch (pes cavus)
specific foot dorsiflexion weakness via COMMON PERONEAL NERVE involvement
differential for Friedreich ataxia - C-M-T disease does NOT have heart involvement
Rhabdomyolysis
causes? pain? labs?
trauma, sepsis, drugs (statin, alcohol, cocaine) and overexertion
myalgia in proximal mm., lower back + calves
high CK, AKI and electrolyte issues (HYPERkalemia/-phosphatemia, HYPOcalcemia, metabolic acidosis)
heme from myoglobin causes ATN with GRANULAR BROWN CASTS
false-positive dipstick for blood, no RBCs in urine
Scaphoid fracture
location? cause? s/s?
complication?
Scaphoid - proximal row, radial-most carpal
Cause - fall onto outstretched hand; direct axial compression or wrist hyperextension
S/s - wrist pain in ANATOMICAL SNUFFBOX (EPL + APL/EPB tendons)
Complication - AVASCULAR NECROSIS with NONUNION
(fracture creates 2 fragments > dorsal scaphoid branch of radial a. enters distal fragment + runs retrograde to proximal fragment, which may necrotize when connection is disrupted)
Osteonecrosis of femoral head
How? What artery?
femoral neck fracture can injure the MEDIAL CIRCUMFLEX ARTERY (from deep femoral a.) which gives most of the head its blood supply
What is Trendelenburg gait?
What is an iatrogenic cause of it?
When abductors (glut med/min) are weak on one side, there will be contralateral hip drop when the contralateral foot is lifted while walking.
IM injection in the buttock can paralyze the SUPERIOR GLUTEAL NERVE (L4-S1, suprapiriform hiatus) if done into the SUPEROMEDIAL quadrant of the buttock
How should IM injections to the butt be done?
To avoid what?
In the ANTEROLATERAL gluteal area (von Hochstetter triangle)
Put PALM ON GREATER TROCHANTER and INDEX FINGER ON ASIS … spread middle finger out and triangle is btwn index and middle finger
to avoid nerve damage to gluteal or sciatic nerves (SUPERIOR GLUTEAL N. –> trendelenburg gait)
Osteoarthritis vs. RA
age? joints? morning sx? systemic sx? examination
age:
OA = >40
RA = 40-60, but often younger
joints:
OA = Knees, Hips, DIP, 1st CMC
RA = MCP, PIP, wrist
morning stiffness:
OA = none or <30 min
RA = prolonged
systemic sx:
OA = none
RA = fever, fatigue, weight loss
examination:
OA = hard, bony joint enlargement
RA = soft, spongy, warm joints
Heberden and Bouchard nodes in OA
what are they?
DIP enlargement - Heberden
PIP enlargement - Bouchard
via osteophytes
Osgood-Schlatter disease
what is it? cause?
overuse injury of the SECONDARY OSSIFICATION CENTER of the TIBIA
REPETITIVE QUAD CONTRACTION and CHRONIC AVULSION cause patellar ligament to separate from the tibial tuberosity > forms a CALLOUS that elevates the tuberosity
Osgood Schlatter disease
epidem? s/s?
YOUNG ATHLETES after a RECENT GROWTH SPURT
pain + swelling at TIBIAL TUBERCLE
relieved by rest
reproduced by SEATED KNEE EXTENSION
Pes anserinus bursitis
what? in whom?
ANTEROMEDIAL KNEE PAIN in a RUNNER
Muscles inserting at the pes anserinus (3)
semitendinosus
gracilis
sartorius
calcium / PTH / phosphorus levels in osteoporosis?
how are they usually, how might they be in certain situations?
usually NORMAL unless osteoporosis is SECONDARY
torticollis cause (2 cats, w/ examples)
uterine malposition - fetal macrosomia or oligohydramnios
birth trauma - breech delivery
what is foot “eversion”?
same as pronation
mediated by peroneus longus muscle (superficial peroneal n.) … fibular head fractures can injure this nerve
what is foot “inversion”?
same as supination
mediated by TIBIALIS POSTERIOR innervated by TIBIAL NERVE
fibular neck fracture
complications?
common peroneal nerve injury
impaired eversion (pronation) and dorsiflexion loss of dorsal foot sensation
saphenous nerve injury
sx?
loss of medial leg sensation
tibial nerve
innervates what?
injury causes what?
skin - posterior calf, lateral foot + sole, knee joint, plantar flexion/inversion muscles (gastroc, soleus, tib post)
weak plantar flexion / inversion
numb sole
Rotator Cuff Syndrome
main injured tendon + sx
SUPRASPINATUS tendon (repeated impingement trauma btwn humeral head + acromion; as in GOLF or other repeated abduction movements)
painful abduction (especially against resistance)
Orthopedic test to isolate the supraspinatus when testing rotator cuff function
“empty can” test
abduct arms 90 degrees to side, flex them 30 degrees forward and point thumbs to floor
apply downward force to arm while patient presses up; may elicit pain in supraspinatus tendon impingement
Sudden upward jerking of the arm at the shoulder
can cause what?
injury to the “lower trunk” of the brachial plexus (C8 to T1) giving the MEDIAN and ULNAR nerves
“Klumpke’s palsy” - paralysis of all INTRINSIC hand muscles with “total claw hand deformity” due to relative sparing of extrinsic flexors + extensors
Besides the intrinsic hand muscle paralysis and “total claw hand deformity” of Klumpke’s palsy (lower trunk brachial plexus injury)…
what other symptoms / syndromes (2) can present?
- Sensory loss - over MEDIAL HAND/FOREARM (ulnar nerve)
2. Ipsilateral HORNER SYNDROME - if T1 nerve root is involved
Shoulder dislocation / fracture of proximal humerus…
what can it injure?
what would this cause?
axillary nerve
weak deltoid (abduction) and teres minor (external rotation)
Midshaft humerus fracture…
what can it injure?
what will this cause?
radial nerve
posterior forearm + dorsolateral hand numbness wrist drop (paralyzed extensors)
trauma to the elbow or wrist resting on a hard surface for prolonged periods
what can it injure?
what will it cause?
ULNAR NERVE (C8-T1) injury (medial epicondyle fracture > “funny bone”; wrist on hard surface > Guyon’s canal)
sensory loss over dorsal + palmar hand last 1.5 digits
affected movements:
wrist flexion/adduction (flexor carpi ulnaris)
finger abduction/adduction (interossei)
flexion of 4th/5th digits
weak lumbricals > ULNAR CLAW during finger extension (last 2 digits can’t extend)
“Simian hand” palsy
injury of what
median and ulnar nerves
“Preacher’s hand”
injury of what?
pt tries to make fist and only the last 2 digits flex
median nerve
which structure is weakened in patients with direct inguinal hernia?
transversalis fascia
direct hernia is medial to inferior epigastric vessels
Supracondylar humeral fracture with ANTEROLATERAL displacement of the proximal segment
can injure what?
radial nerve
Supracondylar humeral fracture with ANTEROMEDIAL displacement of the proximal segment
can injure what?
median nerve and brachial artery
1 dislocated joint and #1 direction of dislocation
glenohumeral joint (shallow articulation btwn humeral head and glenoid fossa)
ANTERIOR dislocation is most common
common position of arm during anterior dislocation of humerus
abducted and externally rotated
as in throwing a football
consequences of anterior humeral dislocation
what is injured? how does it present?
AXILLARY NERVE is injured
- deltoid prominence is FLATTENED
- acromion PROTRUDES
- there is ANTERIOR AXILLARY FULLNESS (humeral head moves into this space)
what does the axillary nerve innervate?
2 muscles and what skin
deltoid
teres minor
overlying skin of lateral shoulder
What injury results from a DOWNWARD BLOW to the tip of the shoulder?
how does it present?
acromioclavicular subluxation
swelling + UPWARD DISPLACEMENT OF CLAVICLE
no specific nerve injuries or deficits
Where are most clavicular fractures? How do they present?
middle 1/3 of clavicle via direct blow
local swelling + tenderness; no specific neurovascular damage
how would a CORACOID PROCESS FRACTURE occur?
rarely, but via FIRING A SHOTGUN/RIFLE
What rare fracture can occur due to TORSION from a FALL ON OUTSTRETCHED HAND?
presentation (3)? structure injured?
spiral fracture of midshaft humerus
swelling, bone crepitus, ecchymoses
RADIAL NERVE is injured
Limb reflexes mnemonic
- Achilles - S1, S2 “buckle my shoe”
- Patellar - L3, L4 “kick the door”
- Biceps/brachioradialis - C5, C6 “pick up sticks”
- Triceps - C7, C8 “lay them straight”
Myotonic Muscular Dystrophy (type 1)
inheritance? mutation + gene?
AD inheritance of CTG repeat expansion
DMPK gene > abnormal expression of MYOTONIN PROTEIN KINASE
CTG hints at symptoms: Cataracts, Toupee (early balding) and Gonadal atrophy
Myotonic Muscular Dystrophy (type 1)
6 S/S?
the genetic abnormality hints at a mnemonic for 3 of the sx
CTG repeats > 1) Cataracts, 2) Toupee (early balding) and 3) Gonadal atrophy
4) Wasting
5) Arrhythmia
6) Myotonia - delayed relaxation after voluntary or electrostim’d contraction
CTG WAM
Osteogenesis Imperfecta
genes involved + inheritance + defect
variable; most commonly AD form with DECREASED PRODUCTION of otherwise normal TYPE 1 collagen
usually COL1A1 or COL1A2
problem forming TRIPLE HELIX of collagen alpha chains
Osteogenesis Imperfecta
S/S? (mnemonic)
Differential and Tx?
Patients can’t “BITE”
- Bones - fractures
- I - eyes (BLUE SCLERA)
- T - teeth - dental imperfections
- E - ears - hearing loss via ossicle issues
Must diff from suspected child abuse
Tx with BISPHOSPHONATES to decr. fractures
Achondroplasia
gene/protein involved?
inheritance?
risk via which parent + how?
FGFR-3 has CONSTITUTIVE ACTIVATION which actually inhibits chondrocyte proliferation, affecting ENDOCHONDRAL OSSIFICATION + thus longitudinal growth
> 85% sporadic; can be AD with full penetrance (homozygote = lethal)
related to increased PATERNAL AGE
(#1 dwarfism)
From what part of bone does healing of a fracture with new bone formation occur?
periosteum
cytokine involved in osteoporosis
IL-1
How does alcohol precipitate gout attacks?
alcohol metabolites compete for same excretion sites as uric acid in kidney > decreased urate excretion and buildup in blood
Most (90%) of gout is via UNDEREXCRETION of urate and is idiopathic / medication-exacerbated (via thiazides/loops or CKD)…
what FOUR conditions cause OVERPRODUCTION-related gout?
- Lesch-Nyhan
- PRPP excess
- tumor lysis or other high turnover states
- VON GIERKE DISEASE
Aseptic necrosis / avascular necrosis (same thing)
main risk factors (3)
minor risk factors (3)
associations (5)
main - alcohol, fractures/dislocations + high dose steroids
minor - radio + chemotherapy, organ transplants
associations - SLE, sickle cell, GAUCHER (glucocerebrosidase defic.) and decompression syndrome (Caisson)
Musculocutaneous nerve injury
s/s?
“musculo-“ - inability to flex biceps/coracobrachialis
“cutaneous” - absent sensation over LATERAL FOREARM
What is the serum marker for OSTEOBLAST activity?
how can it be differentiated from other sources of similar molecules?
serum bone-specific alkaline phosphatase
ALP is also found in intestine, LIVER (main contributor aside from bone) and placenta
to diff liver and bone ALP:
1. Bone ALP is easily denatured by heat (“bone boils”)
- Liver ALP rises are often accompanied by GGT rises
(electrophoresis and mAbs can also be used)
What are two URINARY markers for OSTEOCLASTIC activity?
1 much better than the other
- urinary DEOXYPYRIDINOLINE excretion - DOP cross-links collagen fibers and is released into circ when osteoclasts resorb bone
- urinary hydroxyproline - but many meat products can also raise urine levels
what is one SERUM marker for OSTEOCLASTIC activity?
not commonly used, why?
TARTRATE-resistant ACID PHOSPHATASE
cross reacts with acid phosphatase from other tissues and is unstable in frozen serum samples
Ca-PPi deposition disease
in whom? cause (4)?
pts mostly > 50, both sexes equally
mostly idiopathic
sometimes w/ 1) hemochromatosis, 2) hyperparathyroidism, or 3) joint trauma
Ca-PPi deposition disease
main joint? x-ray? crystals?
mostly KNEE joint
“CHONDROCALCINOSIS” on x-ray (calcification of cartilage)
crystals are RHOMBOID and POSITIVELY BIREFRINGENT (blue when parallel to light)
Ca-PPi deposition disease
acute tx
prophylaxis
acute: NSAID, colchicine, steroids
proph: colchicine
Femoral hernia
in whom? via weakness of what? risk?
in WOMEN via weakness of the PROXIMAL FEMORAL CANAL
bowel entry through femoral ring is at particularly high risk of STRANGULATION
Femoral hernia
contents protrude through what into what? relation to inguinal ligament?
through FEMORAL RING into FEMORAL CANAL
travels INFERIOR to inguinal ligament
(direct and indirect inguinal hernias are superior to ligament; differentiated by indirect being lateral to epigastric vessels and direct being medial)
Non-traumatic radial nerve injury in forearm
how does it occur + what does it cause?
Repetitive pronation/supination (ie using a screwdriver)
injures radial nerve as it passes THROUGH SUPINATOR M.
weak EXTENSION of FINGERS
sensation usually preserved + no issues proximal to supinator (eg, triceps or extensor carpi radialis issues - elbow + wrist extension are ok)
Ehlers-Danlos types I and II
what is mutated?
type V collagen
> hypermobile joints + hyperextensible, fragile skin
(most common E-DS form)
What muscles are innervated by the ULNAR nerve?
6
- FC Ulnaris - wrist flexion/adduction
- FD Profundus
- Opponens, flexor + abductor DIGITI MINIMI
- INTEROSSEI- palmar add/flex/ext, dorsal abduct
- LUMBRICALS - flex mcp, extend ip
- ADDUCTOR POLLICIS - only thumb m. via ulnar
What are the changes seen in osteoBLAST, osteoCLAST and RANKL activity in osteoporosis?
osteoblast activity is DECREASED
osteoclast activity and RANKL levels are INCREASED
Aside from vertebral compression fractures (acute back pain, height loss + kyphosis)…
what are two common fracture sites in osteoporosis?
FEMORAL NECK
and DISTAL RADIUS (so-called Colles fracture)
1 vertebral subluxation in rheumatoid arthritis?
iatrogenic trigger?
atlantoaxial joint because C1 (atlas) is highly mobile relative to C2 (axis)
endotracheal intubation can worsen it > SC or vertebral artery compression
presentation of acute spinal cord injury (ie, in RA cervical subluxation)
2 phases
- FLACCID paralysis - decreased/absent reflexes below lesion due to “spinal shock”
- SPASTIC paralysis - after days-weeks when spinal shock resolves
regional anesthesia technique for SHOULDER/UPPER ARM procedures?
associated complication?
contraindications (2) due to this complication?
INTERSCALENE nerve block - btwn ant./middle scalene muscles
PHRENIC PARALYSIS - transient ipsilateral diaphragm paralysis due to phrenic n. (C3-C5) being affected
CI in chronic lung disease or contralateral phrenic n. dysfunction
Platysma innervation
cervical branch of FACIAL NERVE
