Musculo/Derm 1 Flashcards
Where does the Anterior Cruciate Ligament run from?
Lateral femoral condyle to anterior tibia
Where does the Posterior Cruciate Ligament run from?
Medial femoral condyle to posterior tibia
What is a Valgus deformity?
Knock kneed, lower leg abducted
What is a Varus deformity?
Bow legged, lower leg adducted
What stress does the Medial Collateral Ligament resist?
Resist valgus stress
What stress does the Lateral Collateral Ligament resist?
Resists varus stress
What are the attachments of the Lateral Collateral Ligament?
Lateral epicondyle of femur and head of fibula
What are common presentations of knee injuries?
Swelling, instability, sensation that knee will ‘give out’
What is the most commonly injured knee ligament?
ACL
What often causes ACL injury?
Noncontact athletic injury, e.g., running/jumping, sudden change of direction
What are two tests for ACL injury?
Anterior drawer: bend knee 90 degrees
Lachman test: bend knee 30 degrees
What often causes PCL injury?
Trauma, dashboard injury
How does MCL injury present?
Abnormal passive abduction of lower leg, medial space widens
What is the Unhappy triad?
Triad of injury common in contact sports, includes: ACL tear, MCL tear/sprain, Medial meniscal tear
What force leads to an Unhappy triad?
Lateral to medial force applied to knee when foot planted
What often causes LCL injury?
Trauma to medial knee
How does LCL injury present?
Abnormal passive adduction of lower leg
When does a Meniscal Tear often occur?
When foot is planted and there is sudden change in direction, twisting the knee
How to perform McMurray test?
Patient supine with knee flexed, extend knee while rotating foot
-Internal rotation tibia → tests lateral meniscus
-External rotation → tests medial meniscus
What type of joint is the knee?
Synovial joint
What is a bursa?
Synovial lined sac that acts as a cushion between bones and tendons/muscles
What often causes Prepatellar Bursitis?
Repeated kneeling (‘Housemaid’s knee’), Gout, infection
How does Prepatellar Bursitis present?
Swelling and warmth anterior to patella
What is a Baker’s Cyst?
Fluid collection in the Gastrocnemius-semimembranosus bursa (Popliteal cyst)
Often related to Chronic joint disease because it communicates with synovial space
What is the clinical presentation of a Baker’s Cyst?
Often small, asymptomatic. May cause posterior knee pain/swelling that worsens with activity. Can rupture and cause acute pain that mimics DVT.
In what condition are Baker’s Cysts common?
Rheumatoid arthritis
What is Osgood Schlatter Disease?
Tibial tuberosity avulsion from overuse. Usually benign, self-limited condition. Pain/swelling at tibial tubercle (Secondary ossification center of tibia)
In what age group does Osgood Schlatter Disease usually occur?
Children
What is the clinical presentation of a Patellar Fracture?
Cannot extend knee against gravity
What can cause inability to extend knee against gravity?
Patellar fracture, Quadriceps tendon tear, Injury to patellar tendon
What is the Glenoid?
Fossa of scapular bone
What are the 4 rotator cuff muscles?
(SITS) Supraspinatus, infraspinatus, teres minor, subscapularis
What does Rotator Cuff Tendonitis cause?
Pain with abduction
What does a Rotator Cuff tear lead to?
Inability to abduct
What is the action of the Supraspinatus?
Initial abduction (0-15°)
Innervation: Suprascapular nerve
What is the most common rotator cuff injury?
Supraspinatus
Why is the Supraspinatus vulnerable to impingement?
Tendon travels between humeral head and acromion process of scapula. Inflammation or tear can occur.
What are two tests that can identify Supraspinatus injury?
Empty Can Test, Full Can Test
What is the action of the Infraspinatus?
Assists in external rotation/abduction of shoulder
What nerve innervates the Infraspinatus?
Suprascapular
Who commonly injures the Infraspinatus?
Overhead throwers (pitchers)
What is the action of Teres Minor?
External rotation/adduction of shoulder
Innervation: Axillary nerve
What is the action of Subscapularis?
Internal rotation
Innervation: Upper/lower subscapular nerves
What muscles are responsible for full range abduction of the arm?
Supraspinatus: First 15°, Deltoid: up to 90°, Trapezius/serratus anterior: abduction beyond 90°
What type of dislocation typically occurs in shoulder dislocation?
Anterior dislocation of the humeral head
What nerve is commonly injured in shoulder dislocation?
Axillary nerve, leading to sensory loss of deltoid and weak abduction (usually too painful to move)
Where does a Humerus Fracture often occur?
Proximal humerus, which may disrupt blood supply leading to avascular necrosis of head and injury to axillary nerve causing loss of arm abduction
What is Epicondylitis?
Pain at epicondyle from overuse, few inflammatory cells + disorganized tissue/vessels
What causes elbow pain in Lateral epicondylitis?
Wrist extension (tennis elbow)
What causes elbow pain in Medial epicondylitis?
Wrist flexion (golfer’s elbow)
What is nursemaid elbow?
Radial head subluxation caused by axial traction on pronated forearm, leading to annular ligament slipping over head of radius
What is the most common pediatric elbow fracture?
Supracondylar Fracture, often occurring from falling on an outstretched arm
What is at risk for injury in a Supracondylar Fracture?
Brachial artery and Median nerve (travels with brachial artery) → most common neurovascular artery, Radial or ulnar nerves
What are two muscles innervated by the axillary nerve?
Teres minor, deltoid
What are the presentations of Radial Nerve Lesions?
Triceps weakness, Wrist drop, Sensory loss of back of hand/forearm
What are common causes of Radial Nerve Lesions?
Midshaft humeral fracture, Crutches, ‘Saturday night palsy’
Where does the Radial Nerve run?
Spiral/radial groove
What is the presentation of a radial nerve lesion at the radial groove?
Triceps spared, Most sensory nerves (arm/forearm) unaffected, Weakness wrist/finger extensors, Sensory loss of dorsal hand
What are the nerve roots for Musculocutaneous Nerve?
C5-C7 (lateral cord of brachial plexus)
What does the Musculocutaneous Nerve innervate?
Biceps and sensation to lateral forearm
What is Erb’s palsy?
Upper plexus (C5-C6) injury caused by excessive angle at neck/shoulder. Classic cause: Birth Trauma
What nerves are injured in Erb’s palsy?
Axillary, Musculocutaneous, Suprascapular
What is the clinical presentation of Erb’s palsy?
Arm straight at side + internally rotated (‘Waiter’s tip’)
What is Klumpke Palsy?
Lower Plexus (C8-T1) Injury caused by excessive abduction of arm, e.g., catching a tree branch while falling
What nerves are injured in Klumpke Palsy?
Median and Ulnar
What is the clinical presentation of Klumpke Palsy?
Clawed hand: MCP hyperextended, IP joint flexed (other flexors at wrist are spared)
What is Thoracic Outlet Syndrome?
Compression of nerves/vessels leaving thorax, occurs above first rib and behind clavicle (Scalene triangle)
What does the scalene triangle consist of?
Anterior scalene, Middle scalene, Above first rib
What predisposes an individual to Thoracic Outlet Syndrome?
Extra rib from 7th cervical vertebrae
What are three clinical features of Thoracic Outlet Syndrome?
Injury to Brachial plexus → Klumpke palsy, Venous compression → Arm swelling, Arterial compression (rare) → hand ischemia (cool temp, pallor) + weak distal pulses
What does the Long Thoracic nerve innervate?
Serratus anterior muscle
What does injury to Long Thoracic nerve lead to?
Winging of scapula
What is the most commonly fractured carpal bone?
Scaphoid, classically caused by FOOSH injury
What are two complications of a Scaphoid fracture?
Avascular necrosis, nonunion
What is the blood supply to the Scaphoid?
Palmer and dorsal branches of Radial artery, Retrograde flow
What is the Lunate attached to?
Radius
What can Lunate dislocation cause?
Carpal tunnel, median nerve dysfunction.
What ligament forms the Carpal tunnel?
Transverse carpal ligament (flexor retinaculum)
What does a Median nerve lesion at carpal tunnel lead to?
Loss of Thumb movement, flexion/extension of lateral fingers (lumbricals), sensory loss of lateral 3.5 fingers
Sensation at thenar eminence is spared because there is a branch that comes off the median nerve before the carpal tunnel
What is the clinical presentation of Carpal Tunnel Syndrome?
Begins with sensory symptoms, hallmark is pain or paresthesia
What are eight risk factors for Carpal Tunnel Syndrome?
Repetitive use of hands/wrists, Obesity, Pregnancy (edema), Other disorders: Diabetes, Rheumatoid arthritis, Hypothyroidism, Acromegaly, Dialysis related Amyloidosis (deposits of β2 microglobulin)
What is a classic sign of Acromegaly?
Increasing glove/shoe size
What is the Guyon’s canal?
Ulnar canal, located above transverse carpal ligament + roof formed by palmar fascia
What do Ulnar Nerve Lesions lead to?
Loss of Finger abduction/adduction (interossei), Motor/Sensory loss to little and ring finger
In which activity are many cases of Guyon’s Canal Syndrome reported?
Bicyclists (overuse of wrist)
What type of fractures are pediatric fractures often?
Incomplete
What is a Greenstick Fracture?
Pediatric fracture → Bent bone, fracture does not extend through width of bone
Often due to FOOSH injury
What force causes a Greenstick Fracture?
Bending force applied to bone, often occurs in distal radius
What is a Torus Fracture also called?
Buckle fracture
What is a Torus Fracture due to?
Axial force trauma
Where does a Torus Fracture occur?
Distal metaphysis (most porous bone)
What are the Intrinsic Hand muscles?
Thenar, Hypothenar, Interosseous muscles (abduction/adduction), Lumbrical muscles
What innervates the Interosseous muscles of the hand?
Ulnar nerve
What are the three Thenar muscles?
Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis
What are the three Hypothenar muscles?
Abductor digiti minimi, Flexor digiti minimi brevis, Opponens digiti minimi
Which Interosseous muscles cause finger abduction?
Dorsal
Which Interosseous muscles cause finger adduction?
Palmer
Where do Lumbricals originate from?
Tendons of flexor digitorum profundus
What is the action of the Lumbricals?
Flex MCP joints, Extend IP joints (form L shape)
What innervates the Lumbricals?
Medial two lumbricals: ulnar nerve, Lateral two lumbricals: median nerve
What does loss of lumbricals lead to?
Claw fingers
What is the innervation for Flexor digitorum profundus?
Lateral two digits: Median nerve, Medial two digits: Ulnar nerve
What innervates the Extensor digitorum?
Radial nerve
What are two major Wrist flexors?
Flexor carpi radialis, Flexor carpi ulnaris
What are three major Wrist extensors?
Extensor carpi radialis longus, Extensor carpi radialis brevis
What is the innervation for Flexor digitorum profundus?
Lateral two digits: Median nerve
Medial two digits: Ulnar nerve
What are 2 major Wrist flexors?
Flexor carpi radialis
Flexor carpi ulnaris
What are 3 major Wrist extensors?
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
The wrist will deviate to which side with median nerve lesion?
Ulnar side
What are 2 ways to test for Median Nerve Lesions? What is the presentation?
Ask patient to make a fist → unable to flex thumb and lateral digits → ‘Pope’s blessing’ ask
At rest → Thumb adducted, thenar atrophy → ‘Ape hand’
Will median nerve wrist lesions lead to wrist deviation?
No, flexor muscles are intact
What are 2 causes of Median nerve wrist lesions?
Laceration
Carpal tunnel
What is a cause of Median nerve elbow lesion?
Supracondylar fracture of humerus
Median Nerve Lesion at the elbow will have what clinical presentation?
-Loss of flexors/pronators in forearm → forearm supinated
-Ulnar deviation
What does the Recurrent branch of the median nerve supply?
Motor innervation to thenar muscles, no sensory innervation
Recurrent branch of the median nerve is injured with?
Superficial laceration
Injury to the Recurrent branch of the median nerve lead to?
Thumb immobilization
Ulnar Nerve Lesions lead to?
-Loss of abduction/adduction (interossei)
-Motor and sensory loss to little/ring fingers
What is a clinical sign of Ulnar Nerve Lesions? Why?
Loss of medial lumbricals → extension of MCP joint + flexion at IP joint at rest → Ulnar claw
What Elbow lesion can lead to Ulnar nerve damage?
Fracture at medial epicondyle
Fracture at medial epicondyle leads to?
Ulnar nerve damage
Ulnar nerve lesion at Proximal Elbow presents with?
Loss of flexor digitorum profundus → Ulnar digits paralyzed without clawing
Lumbar Plexus includes what nerve roots?
T12 to L4
Sacral plexus includes what nerve roots?
L4-S4
What does the Iliohypogastric nerve innervate?
-Motor: internal oblique and transversus abdominis
-Sensory: Suprapubic (hypogastric) region
Iliohypogastric nerve is commonly injured in?
Abdominal/pelvis surgery
Iliohypogastric nerve injury after surgery leads to?
Burning pain or paresthesia that radiates from incision to suprapubic area
What does the Genitofemoral nerve innervate?
Motor: Cremasteric muscle
Sensory:
-Genital branch: skin of anterior scrotum, mons pubis and labia majora
-Femoral branch: skin upper anterior thigh
Genitofemoral nerve injury leads to?
Absent cremasteric reflex
↓ sensation anterior thigh
↓ sensation labia/scrotum
Lateral Femoral Cutaneous compression occurs via?
Tight clothing, obesity, pregnancy
Lateral Femoral Cutaneous compression leads to?
Meralgia paresthetica: burning pain/paresthesia over outer thigh
What does the Obturator Nerve innervate?
Motor: Thigh adductors
Sensory: Medial thigh
Thigh adductors include?
Adductor Longus
Adductor Brevis
Adductor Magnus
Gracilis
Obturator Externus
Obturator nerve is often injured during?
Pelvic surgery
Femoral nerve innervates?
Motor: Hip flexors and knee extensors
Sensory:
-Anterior femoral cutaneous branches: anteromedial thigh
-Saphenous nerve: Medial leg and foot
What are the 3 hip flexors innervated by the femoral nerve?
Pectineus
Iliacus
Sartorius
What is the knee extensor innervated by the Femoral nerve? What does it include?
Quadricep femoris
-Rectus femoris
-Vastus lateralis
-Vastus medialis
-Vastus intermedius (deep to rectus)
Saphenous vein stripping is commonly used for?
CABG
Saphenous vein stripping can lead to?
Damage to saphenous nerve → numbness in medial leg and foot
How to perform a Femoral nerve block?
Find femoral artery then move laterally to find nerve (NAVL)
Rarely Femoral nerve can be injured in?
Pelvic fracture or surgery
Femoral nerve injury will lead to?
-Weakness in flexion of thigh and extension of knee
-Absent patellar reflex
-Numbness, tingling in thigh/knee
What is the largest nerve in the body?
Sciatic nerve
What are the 2 branches of the sciatic nerve?
Common peroneal and tibial
What are the sensory and motor functions of the Common peroneal nerve?
-Motor: Short head of biceps femoris → flexes knee
-Sensory: lower leg and dorsum of foot
What are the branches of the Common peroneal nerve?
Superficial and deep fibular nerve
Superficial fibular nerve innervates which muscles? What is the action?
Muscles of lateral lower leg
-Fibularis longus and brevis → Evert the foot
Deep fibular nerve innervates which muscles? What is the action?
Muscles of anterior lower leg
-Tibialis ant, extensor digitorum longus, extensor hallucis longus → Dorsiflexion of foot, extension of toes + some intrinsic muscles of foot
Common Peroneal Nerve is injured by?
-Prolonged lying (bed rest, surgery)
-Leg casts
-Fibular neck fracture
Injury to Common Peroneal Nerve leads to?
-Foot drop (loss of dorsiflexion)
-Sensory loss of dorsum foot, lateral shin
Tibial nerve travels?
Down the leg posterior to tibia → travels under medial malleolus through tarsal tunnel
Tibial nerve innervates?
Posterior leg muscles + sensory to heel/sole
What are the Posterior Leg Muscles?
-Popliteus
-Flexor hallucis Longus
-Flexor digitorum Longus
-Tibialis posterior
-Plantaris
-Soleus
-Gastrocnemius
What are the 3 actions of the Posterior Leg Muscles?
Plantar flexion
Toe flexion
Inversion
Tibial Nerve Damage can occur due to?
-Tarsal tunnel narrowing
-Large Baker’s cyst (rare)
-Trauma
Tarsal tunnel narrowing will damage what nerve? What are the symptoms?
-Tibial nerve
-Mostly sensory, pain and numbness on sole of foot
A Large Baker’s cyst can damage the tibial nerve and cause loss of?
Plantar flexion
Toe flexion
Loss of inversion
What are the motor and sensory innervations for the Pudendal nerve?
Motor:
-Muscles of perineum
-External urethral sphincter
-External anal sphincter
-Levator ani
Sensory: penis/clitoris and skin of perineum
Pudendal Nerve is often injured from?
Vaginal childbirth
Injury of the pudendal nerve leads to?
-Urinary/fecal incontinence
-Vulvar/scrotal pain
Pudendal Nerve Block is used in?
Vaginal childbirth to reduce pain (largely replaced)
Pudendal Nerve Block involves anesthesia to what area?
Ischial spine of pelvis
What is Radiculopathy?
Compression of nerve root at the spine
What are 3 possible causes of Radiculopathy?
Spinal stenosis
Herniated disc
Spondylolisthesis
What are the 2 components of the Intervertebral Discs?
Outer fibrous ring: annulus fibrosus
Soft center: nucleus pulposus
What is the most common cause of radiculopathy?
Herniated disc
What causes a Herniated disc? What does it cause?
Degeneration of annulus fibrosis → extrusion of nucleus pulposus → unilateral nerve compression
Herniated disc often occurs anteriorly or posteriorly? Why?
Posteriorly, posterior longitudinal ligament is weaker than anterior ligament
Where is the Posterior longitudinal located? What does it cover?
Sits within spinal canal, covers posterior surface of vertebrae
