USMLE MSK/Anatomy

ANATOMY: 1) Which muscles insert on the lateral epicondyle of the humerus? Medial epicondyle?

Lateral epicondyle - Wrist EXTENSORS Medial epicondyle - Wrist FLEXORS

CLASSIC PRESENTATION: Tennis player presents with pain at the elbow when trying to extend his wrist.

Lateral epicondylitis is inflammation at the lateral epicondyle from overuse. Wrist extension is impaired bc thats where the wrist extensors insert.

ANATOMY: 1) Where does the ACL attach to on the femur? 2) PCL? 3) What do they prevent?

Lateral femoral condyle and anterior tibia is where ACL attaches. Stops the knee from going forward (Anterior Drawer Sign) Medial femoral condyle and posterior tibia is where PCL attaches. Stops the knee from going backward (Posterior Drawer Sign) LAMP

ANATOMY: Latissmus Dorsi 1) Which nerve innervates it? 2) What movement does it do?

Latissimus dorsi is innervated by the Thoracodorsal Nerve and it's used for arm adduction, internal rotation, and extension.

NERVE: Thoracodorsal Nerve 1) What muscle does it innervate? What motion? 2) What nerve roots?

Latissimus dorsi orginates from spinous processes of the back and inserts in the bicipital groove of the humerus. 1) Innervated by the THORACODORSAL NERVE from C6-8.

Which organ is the least vulnerable to infarction?

Liver has dual circulation systems: portal vein and hepatic artery. There's also chance for retrograde flow through accessory vessels.

ANATOMY: What are the two branches of the radial nerve? 1) Which branch goes through the supinator muscle?

The radial nerve is on the LATERAL epicondyle of the humerus and gives rise to the superficial and deep branches. 1) Superificial branch is pure sensory and only innervates the dorsal hand 2) Deep branch goes through the supinator and then gives rise to the Posterior Interosseous which causes finger and thumb extension.

What are the 5 intrinsic muscles of the larynx? What nerve innervates it? How is the left and right nerve relations different?

The recurrent laryngeal muscle innervates the intrinsic muscles of the larynx: 1) Posterior cricoarytenoid 2) Lateral cricoarytenoid 3) Oblique arytenoid 4) Transverse arytenoid 5) Thryoarytenoid - The Right recurrent laryngeal hooks around the right subclavian - The Left recurrent laryngeal hooks around the arch of the aorta Both branches lie btw the trachea and the esophagus.

CLASSIC PRESENTATION: During operation, surgeon clamps the subclavian and axillary arteries. What prevents the scapula from ischemic injury? 1) What are the 2 main arteries that give rise to the other 4 branches?

The subclavian and axillary arteries can be bypassed by anastomses of the thyrocervical and subscapular arteries: 1) Transverse Cervical 2) Suprascapular 3) Subscapular 4) Circumflex Scapular

CLASSIC PRESENTATION: Child falls while trying to do a hand stand. She feels wrist tenderness but no swelling. X-RAY shows buckling at bony cortex. 1) Where in the bone is injury?

Torus fracture is in incomplete fracture that can happen to children because of an axial force pressing downwards. This causes compression of the METAPHYSIS where bone is most bony, right above the ephyseal growth plate. Incomplete fractures in children bc their bone is more malleable.

MUSCLES: What are the 4 muscles that make up the thenar eminence? 2) Which nerves innervate them?

Abductor pollicis brevis - Median Flexor pollicis brevis - Median Opponens pollcis - Median Adductor pollicis - ULNAR ***Only muscle for ulnar Extensor pollicus longus and brevis (extension) - RADIAL Nerve

What are the structures of the carotid sheath?

Above thyroid (only the internal carotid), be 1) Common and internal carotid 2) Internal Jugular Vein 3) Vagus Nerve

CLASSIC PRESENTATION: Baby stretched his shoulder on the way out of the birth canal causing damage to nerve roots? 1) What 3 nerves are damaged? 2) What muscle will be paralyzed?

Erb's Palsy tear of C5-C6 trunk during birthing trauma if their neck is stretch against the pubic symphysis: Waiter's Tip Position 1) Axillary Nerve: Flat and adducted shoulder (deltoid) 2) Musculocutaneous Nerve: elbow will be extended (biceps paralysis) 3) Subscapular Nerve: arm will be internally rotated with hand out (infraspinatus will be paralyzed)

CLASSIC PRESENTATION: Girl was climbing a tree when she slipped and caught herself on a lower tree branch. Her hand is now clawed and can't come out of that position. 1) What 2 nerves will be injured?

Klumpke Palsy caused by excessive abduction of the arm causing a C8- T1 roots. Mostly causes damage to the ULNAR and MEDIAN nerves: Claw Hand: 1) Metacarpophalangeal hyperextended of all fingers 2) Interphalangeal is flexed BOTH because the lumbrical flex metacarpophalangeal and extend BOTH DIP and PIP 3) Ape hand from paralysis of the opponens pollicus

CLASSIC PRESENTATION: Patient while bending down suddenly feels pain. The pain is sharp, constant, and radiates to his groin. He has decreased pinprick sensation on his inguinal ligament. 1) Which vertebrae is affected? 2) What is weakened? What structure breaks?

L1 radiculopathy is from the nucleus pulpous herniating out the of the vertebrae and compressing nerve roots. This causes compression of the NERVE ROOT below the vertebrae. 1) Inguinal ligament decreased sensation means root L1 is compressed and vertebrae btw T12-L1 herniated out. 2) The annulos fibrosis is weak and allows the nucleus pulposus to bulge out POSTERIORLY since the posterior spinal ligament is so weak.

What are teh dermatomal distributions of the anterior leg and thigh?

L2-L5

CLASSIC PRESENTATION: Patient while bending down suddenly feels pain. He has back pain that radiates to the LATERAL of his leg. On exam, he is unable to walk on his heels and dorsiflex his foot.

L5 radiculopathy caused by herniation of L4-L5 disc, causing compression of L5 root giving rise to the Common peroneal nerve. Important for foot dorsiflexion and inversion, toes extension, and foot eversion.

CLASSIC PRESENTATION: Patient with obesity presents with tingling sensation to anteriolateral thigh.

Lateral Femoral Cutaneous Nerve comes from L2-L3. It's a pure SENSORY nerve to anterior and lateral thigh and can be compressed in obesity, skinny jeans, pregnancy. causing Meralagia paresthetica.

MUSCLE: Which muscles are innervated by the Obturator Nerve?

1) Adductor brevis 2) Gracilis

PHYSIOLOGY: Which nerve is afferent in Gag Reflex? Efferent?

1) CN9 sense from the back of the tongue (AFFERENT) and then send info to the medulla nucleus ambigus. 2) CN10 from nucleus amibgus causes contraction of the pharynx and palate elevation (EFFERENT)

MUSCLE: 1) Which muscle attaches to the infeior distal part of the clavicle? 2) Superior distal? 3) Superior proximal?

1) Deltoid muscle: attaches inferior distal and abducts, flexes, and medially rotates the humerus, This pulls the bone down and can cause an INFERIORLATERAL BREAK. Innervated by the AXILLARY NERVE. 2) Trapezius: attaches to the superior distal clavicle 3) Sternocladomastoid: attaches to the superior proximal clavicle

CLASSIC PRESENTATION: Patient presents with a distal clavicle fracture and displacement after he fell. 1) What muscles are contributing to tension?

1) Deltoid pulling the distal fragment down. 2) Sternocladomastoid + trapezius pulling the proximal segment up.

NERVE: 1) Which muscle does the femoral nerve run anterior of? 2) What muscle does it innervate? What motions? 3) What sensory innervation? What reflex is affected? 4) When is it injured? 5) What's the best landmark to do a nerveblock?

1) Femoral comes from L2-L4 run descends through PSOAS MAJOR, and comes out lateral to the PSOAS. 2) Innervates hip flexors: (muscles connecting to the femur) - Iliacus - Pectineus - Sartorius Also innervates the KNEE extensors (all the muscles in the Quadriceps) - Rectus Femoris - Vastus Lateralis - Vastus Medialis - Vastus Intermedius 3) Sensory to the anterior medial thigh over the knee cap causing a decrease in the PATELLAR REFLEX (while lateral femoral cutranous nerve does anteriolateral). - Also gives rise to the Saphenous Nerve which innervates the skin of the medial foot 4) Injured usually through compression injuries (hematoma or abscess) 5) Femoral Nerve is right below the INGUINAL LIGAMENT

ANATOMY: 1) Which muscle inserts on the greater trochanter of the femur? What motion does this do? 2) Lesser trochanter? What motion does this do?

1) Gluteus medium inserts on the GREATER Trochanter and is important for HIP ABDUCTION. 2) Iliopsoas inserts on the LESSER Trochanter and is needed for HIP FLEXION.

NERVE: What muscles does CN9 innervate? 1) Glands? 2) General sensations? 3) Special sensations?

1) Motor: styelopharyngeus (swallowing) 2) Parasympathetic: PAROTID gland 3) General Sensory: Tympanic membrane, tonsils, upper pharynx, carotid sinus 4) Special Sensory: Posterior 1/3 of tongue

NERVE: Median Nerve 1) What muscle does it innervate? 2) What sensory innervations? 3) What artery runs alongside of it? 4) What two muscles does it lie btw?

1) Motor: thenar muscles (thumb flexion and opposition) and lumbricals (flexion and extension of lateral fingers) 2) Sense: lateral 3.5 fingers from the thumb on the palm side but does not include the thenar eminence 3) Runs alongside the brachial artery

MUSCLES: What are the 3 muscles making up the hypothenar eminence?

1) Opponens digiti minimi 2) Flexor digiti minimi brevis 3) Abductor digiti minimi

CLASSIC PRESENTATION: Patient presents with a proximal clavicle fracture and displacement after he fell. 1) What muscles are contributing to tension?

1) Pectoralis major pulling down the longer part of the clavicle. 2) Sternocladomastoid pulling the proximal segment up.

NERVE: What 2 nerve provide taste sensation to the tongue? Which parts?

1) Posterior 1/3 - Glossopharyngeal 2) Anterior 2/3 - Facial

What structures are in the posterior triangle of the neck?

1) Scalene muscles 2) Veins: external jugular veins, subclavian vein 3) Occipital artery 4) Accessory nerve 5) Branches of the brachial plexus 6) Branches of the cervical plexus 7) Superficial cervical nodes

CLASSIC PRESENTATION: Patient is getting blood drawn and physician accidentally crosses the bicipital aponeurosis. What are the 3 subcutaneous structures? What are the 3 deep structures from lateral to medial?

1) Subcutaneous structures from LATERAL to medial: - Cephalic vein - Median cubital vein (what you're supposed to aim for_ - Basilic vein 2) Deep structures within the actual cubital fossa protected by the bicipital aponeurosis: - Biceps brachii - Brachial Artery - Median Nerve

ANATOMY: 1) Which muscle initiates arm abduction? 2) Gets your arms to make a right angle with your body? 3) Which two muscles abduct you arm above your head?

1) Supraspinatus - first 15 degrees of arm abduction 2) Deltoid - 15-100 degrees 3) Trapezius + Serratus Anterior: more than 180 degrees

CLASSIC PRESENTATION: Patient presents with severe pain in his leg from pressure on the anterior compartment of the leg after surgery in his leg. 1) What structures are being impinged? 2) What if this was in a posterior compartment? 3) Lateral compartment?

Acute compartment syndrome can happen when their is compression of any of the compartments of the leg, since the fascia can't expand, there is no room to shift structures so muscles can have myonecrosis with impaired blood supply. 1) Anterior Compartment = anterior tibial artery + deep fibular nerve 2) Deep posterior compartment = posterior tibial artery + peroneal artery + tibial nerve + tibial veins + peroneal veins 3) Lateral compartment = superficial peroneal nerve

MUSCLE: 1) Which 3 muscles are important for the movements in chewing? 2) Which 1 muscle is important for lowering the jaw? Via which joint? 3) Which nerve innervates?

All the mastication muscles are innervated by CNV3. LOWERING THE JAW: Lateral pterygoid via the TEMPOMANDIBULAR JOINT where it rotates the mandible back to open the jaw MUNCHING: (all elevate the jaw) Medial pteyrgoid Masseter Temporalis

CLASSIC PRESENTATION: Female basketball player jumped and fell sideways while landing. Her knee is swollen and bruised. Her lower leg also appears laxily connected to her upper leg.

Anterior Cruciate Ligament Tear ACL prevents the tibia from moving anterior to the femur. Tearing during sudden internal rotation can cause sudden hemarthrosis and knee swelling, and laxity of the tibia. 1) Anterior drawer test/ Lachman test: try pulling the lower leg in front of the upper leg

CLASSIC PRESENTATION: Basketball player was tackled while trying to make a shot and now has his humerus popped out of the glenoid fossa. 1) What nerve is vulnerable to injury?

Anterior Shoulder dislocation happens when arm is popped out while arm is externally rotated, extended, and abducted. 1) Axillary nerve injuty because it wraps around the neck of humeral head will cause decreased sensation of the deltoid.

NERVE: Axillary Nerve 1) What muscle and what sensation?

Axillary Nerve (C5-C6) 1) Motor: Deltoid Muscle 2) Sensation: skin right above the deltoid

CLASSIC PRESENTATION: Patient with a PMH of rheumatoid arthritis complains of pain at the back of her knee when she stands for a long time. 1) What 2 muscles are involved?

Baker's cyst is caused by fluid accumulation in the gastrocnemius-semimembranous bursa (bursa connecting the tendons of the upper and lower leg which happens in the posterior knee). Since it's connected to the synovial knee joint, degeneration of the knee joint can cause fluid to accumulate in that space.

NERVE: Brachial plexus: 1) Which nerve roots do they originate from? 2) Which muscles do they like in btw?

Brachial plexus is from C5-T1 and passes btw the ANTERIOR AND MIDDLE SCALENE Muscles.

CLASSIC PRESENTATION: A patient who injured their neck during fall presents with neck pain. On exam, he has decreased sensation on his lateral upper arm. Shoulder abduction and elbow flexion is decreased. Biceps DTR is diminished bilaterally.

C5 radiculopathy caused by hernation of the C5-C6 vertabrae. C5 root important for Biceps DTR, arm sensation, and biceps and deltoid innervation.

CLASSIC PRESENTATION: A patient who injured their neck during a fall presents with neck pain. On exam, he has decreased sensation of his right middle finger, decreased triceps strength, and absent triceps DTR.

C7 radiculopathy caused by herniation of the C6-C7 vertebrae. This causes impingement of the C7 nerve root causing triceps motor deficits and lack of sensation along the C7 dermatome (middle finger). 1) Radial nerve comes of C7 - Diminished triceps reflex and wrist extension 2) Median nerve - decreased sensation to palm, middle, and index finger

NERVE: 1) Which sensory innervation does the common peroneal give? 2) Where does the common peroneal nerve run? 3) What 2 branches does it give rise to? What motions do they control?

Common peroneal Nerve (L4-S2) branch of the sciatic nerve wraps around the neck of the fibula. 1) MOTOR: Gives rise to the short head or biceps femori. Also has 2 motor branches - Superificial fibular nerve: muscles of the LATERAL lower leg - Deep Fibular nerve: muscles of the ANTERIOR lower leg for everting the foot, DORSIFLEXING THE FOOT and extending toes 1) Sensation: anterolateral aspect of LOWER leg (outisde of the shin) continuing to the dorsum of the foot ***Compression of the tibula can cause

ANATOMY: What layers will you have to go through to do a Cricothyrotomy?

Criothyrotomy is used to insert a tube btw the thyroid and cricoud cartilege to let air in bc patient has an airway obstruction above (i.e. asphysization from laryngeal edema in anaphylactic shock). 1) Skin 2) Superficial cervical fascia + platysma 3) Deep cervical fascia 4) Cricothyroid membrane (under the cricothyroid muscle)

PATHOPHYSIOLOGY: What degenerates to cause a herniated disc? What is the most common lumbar herniation? Cervical herniation?

Degeneration of the anulus fibrosis causes nucleus pulposus to bulge out. 1) L4/L5 is the most common LUMBAR herniation. 2) C5/C6 and C6/C7 is the most common CERVICAL herniation.

MUSCLE: 1) Which nerve innervates the extensor digitorums? What motion? 2) Where are they found?

Extensor digitorum extends at the metacarpholangeal joint and is found on the PALMAR side. Innervated by the Radial Nerve.

CLASSIC PRESENTATION: Patient who fractured their pelvis in a car accident. They have difficulty flexing their thigh against resistance. 1) What other motion and DTR is affected?

Femoral Nerve injury causes inability to flex hip and extend knee. Patellar reflex will be diminished.

What are the miscles of the quadriceps? What nerves innervate them?

Femoral comes from L2-L4 Also innervates the KNEE extensors (all the muscles in the Quadriceps) - Rectus Femoris - Vastus Lateralis - Vastus Medialis - Vastus Intermedius

CLASSIC PRESENTATION: Patient presents with lateral knee tenderness. Anterior and posterior drawer test were negative. Patient is unable to extend and adduct the leg at the knee.

Fibular collateral ligament tear it is attached to the lateral epicondyle of the femur and the head of the fibula. Not associated with the lateral meniscus (unlike the tibial collateral ligament and the medial meniscus)

MUSCLE: 1) What motion does the Flexor digitorum profundus do? 2) What nerves innervate?

Flexor digitorum profundus are for making the fist-shape. Innervated by both median and ulnar nerve.

NERVE: 1) What roots does the GENITOFEMORAL nerve come from? 2) What muscle does it innervate? 3) What skin does it innervate?

GENITOFEMORAL nerve comes from L1-L2 and innervates the: 1) Motor: Cremasteric muscle There are 2 sensory branches: 2) Genital Sensory: scrotum or the labia majora + mons pubis 3) Femoral Sensory: skin of the upper anterior thigh Medical student holds open retracted skin during abdominal surgery. The patient now has an absent cremasteric reflex and decreased sensation to the anterior thigh.

CLASSIC PRESENTATION: Bicyclist presents with diminished sensation of the dorsomedial hand, medial palm, fifth digit and medial 1/2 of fourth digit.

Guyon's Canal Syndrome

CLASSIC PRESENTATION: Elderly woman fell on her arm and has bruising on her shoulder. XRAY shows a left humerus fracture at the anatomical neck. 1) What is she at risk for?

Humeral neck fractures usually only happen in the osteoperotic population. The head recieves retrograde flow that comes from the anterior and posterior circumflex arteries which anastomose from the axillary artery. Interrupting retrograde flow can cause avascular necrosis of the humaral head.

NERVE: 1) What roots does the Iliohypogastric nerve come from? 2) What muscle does it innervate? 3) What skin does it innervate?

Iliohypogastric nerve comes from T12-L1 and innervates the: 1) Suprapubic region 2) Transversus abdominis and internal oblique Patient has abdominal surgery where there is a TRANSVERSE CUT) and has tingling from the cut radiating to the suprapubic region. Since the lateral cutaneous branch innervates that region.

CLASSIC PRESENTATION: Patient who fell on their arm presents with bruising over lateral right arm and her wrist dropped. X-Ray shows midshaft fracture of the right humerus. 1) Which artery and nerve are likely injured? 2) What sensation is probably lost? 3) If her injury was higher up what other motor loss would be present?

Inability to extend wrist suggests a Radial Nerve Injury which is closely associated with the deep brachial artery. aka brachii profundusUsually caused by fracture of the humerus at the MID-SHAFT. 1) Wrist drop: from lack of innervation to wrist extensors so no wrist extension 2) Sensation loss of the back of hand. 3) Injury to radial nerve at the level of the axilla will also cause TRICEPS WEAKNESS. Would also have sensory loss at the back of the forearm (branches off earlier)

What artery comes in proximity to the recurrent laryngeal nerve?

Inferior thyroid artery are in proximity to the recurrent laryngeal nerve, which is why thryoridictomy can lead to hoarseness of voice.

NERVE: Intercostobrachial Nerve 1) What branch does it come off of? 2) What sensory does it innervate? 3) What motor? 4) When is it commonly injured?

Intercostobrachial Nerve is a PURELY SENSORY nerve and innervates the medial upper arm. It is a branch of the 2nd intercostal nerve. 1) Can be injured during AXILLARY LYMPH NODE DISSECTION.

MUSCLES: 1) What are the roles of the lumbricals? 2) What nerves innervate? 3) What happens when you lose innervation?

Lumbricals: 1) Flex metacarpophalangela joints (btw fingers and wrists) 2) Extend interphalangeal joint (btw the fingers) Last two (near pinky): ulnar nerve First 3 (near thumb): radial nerve Clawed hand when you lose innervation.

BONES: Girl fell on her outstretched right hand. 1) Which is most likely to be dislocated? What is prone to injury and complication will it cause? 2) Which is most likely to be fracture? What is prone to injury and complication will it cause? 3) What are all the bones of the hand? 4) Which presents worse: fracture or dislocation?

Lunate most likely to be dislocated. Scaphoid most likely to be fractured. Straight Line To Pinky, Here Comes The Thumb 1) Scaphoid (from bottom pinky side) - injury to RADIAL ARTERY can cause avascular necrosis or nonunion because blood flow is retrograde hear, and will cause ischemia to the proximal bones 2) Lunate most likely to dislocated posteriorly (bc its attached to the radius so can sometimes remain attached while other bones move forward) and can cause MEDIAN NERVE compression 3) Triquetrium 4) Pisiform 5) Hamate 6) Capitate 7) Trapezoid 8) Trapezium (right below the thumb) Both dislocation and fracture present with decreased grip strength and pain but only dislocation cause obvious swelling and deformities.

ANATOMY: 1) Where does the MCL attach to on the femur? 2) LCL? 3) What do they prevent?

MCL attaches to medial epicondyle of tibia and femur. Prevents VALGUS (knock knee) LCL attaches to the lateral epicondyle of femur and lateral fibula. Prevents VARUS (bowed knee)

NERVE: Musculocutaneous Nerve 1) Motor and sensory innervation?

MUSCULOCUTANOUS (C5-C7) from the LATERAL CORD and innervates the: 1) Motor: Biceps 2) Sensory: Lateral Forearm

CLASSIC PRESENTATION: During exam, you flex patient's hip and knee, twist their foot inwards. You hear a pop and patient feels pain.

McMurray Test looks for a meniscus tear 1) Internal rotation of foot (towards midline) looks for LATERAL MENISUCS tear 2) External rotation of foot looks for MEDIAL MENISUCS tear

CLASSIC PRESENTATION: Football player was tackled during a game from his lateral side as he was standing. and now reports knee pain. When passively adducting his upper leg, he has abnormal abduction of his lower leg. 1) What other ligaments are vulnerable to tearing?

Medial Collateral Ligament Tear from a valgus stretch injury (twisting or blowing a planted foot). 1) TEST: Put hand on lower leg and press in ward, and other hand on upper leg and push outward. If the knee is lax and joint stretches = MCL tear. 2) Tibial collateral ligament 3) Anterior cruciate ligament

CLASSIC PRESENTATION: Golfer presents with pain at the elbow when trying to flex his wrist.

Medial epicondylitis is inflammation at the medial epicondyle from overuse. Wrist flexion is impaired bc thats where the wrist flexors insert.

CLASSIC PRESENTATION: 4 year old presents with pain and inability to move his arm. He was walking and almost fell, but his sister grabbed and lifted him by the arm and preventing him from falling. He holds his right arm to abdomen and has his elbow flexed and pronated. 1) What's been dislocated?

Radial head subluxation where axial traction (lifting boy's arm) causes the radial head to be lifted from the humerus while annular ligament stays in place. This causes the annular ligament holding the radius to the ulna to become entrapped btw the femur and radial head. 1) Child flexes elbow and pronates his arm to avoid feeling pain

CLASSIC PRESENTATION: Tennis player presents with tingling and diminished sensation of the lateral palm, thenar eminence, and palmar aspect of 31/2 digits of the right hand (closer to the thumb). 1) What if patient only had diminished sensation of the fingers? 2) What endocrine disorder can cause this? 3) What iatrogenic cause? 4) Where is the nerve relative to ligament? 5) What side do you expect the wrist to be deviated towards if nerve was lacerated? 6) What is a dislocation that can cause this?

Median nerve compression at the PRONATOR TERES SYNDROME, since nerve passes btw both heads of the pronator teres and then btw the flexor digitorum superficialis and profundus. 1) If only had, then the compression would be happening at the CARPAL TUNNEL (Carpal tunnel syndrome). Carpal tunnel is UNDER the transverse carpal ligament. 2) Wrist will be deviated towards the pinky because lose the flexors near the thumb. 3) Will lose sensation of the lateral 3.5 fingers 4) Will have ape hand, can't oppose the thumb. 2) CAUSES: - Acromegaly: growth of the hand - Dialysis related amyloidosis: carpal tunnel syndrome (amyloid deposits in the carpal tunnel) - Lunate dislocation 3) DIAGNOSTICS: - Tinel exam: tap the canal - Phanel Test: ask patient to have wrist and flexed for more than 60 sec

CLASSIC PRESENTATION: Patient who dislocated his shoulder can't feel his lateral forearm. 1) What position do you expect his arm to be in?

Musculocutaneous nerve compression runs btw the biceps brachii and coroacobrachialis. 1) The biceps will be paralyzed so his arm will be extended and supinated.

NERVE: 1) What nerve does goes through the obturator canal? 2) What muscle does it innervate? What motion? 3) What sensation?

Obturator nerve comes from the lumbar plexus L2-L4 and descends posterior and medial of the illiosoasa and through the OBTRURATOR CANAL. 1) Innervates all the muscles in leg adduction: OBRUTRATOR EXTERNUS Adductor Magnus Adductor Brevis Adductor Longus Gracilis 2) Adducts the thigh ("to close" or bring the leg in) 3) Sensation to the distal medial thigh (ALL middle)

CLASSIC PRESENTATION: Patient presents with elbow discomfort and swelling. She does a lot of bench pressing. She has no pain with elbow extension.

Olecrana bursitis is accumulation of synovial fluid in the olecranon bursa after overuse injury. Since it's a non-inflammatory condition, there is no pain. Bursa is also not in the articular cartiledge, so movement is not impaired.

MUSCLE: Which muscles make up the rotator cuff? Which are used in the internal rotation of the shoulder? Abduction? Adduction? Extension?

SITS = AEEI and 2 at end ADDuction 1) Supraspinatus Abduction First 15 (Most Common injury) - Subscapularis Nerve 2) Infraspinatus External Rotation - Subscapular Nerve 3) Teres Minor External Rotation + ADDuction - Axillary Nerve 4) Subscapularis Internal Rotation + ADDuction - Upper and Lower Subscapular Nerves Internal Rotation: Subscapularis Abduction: Supraspinatus, Deltoid, Triceps, Serratus Anterior Adduction: Subscapularis, Pectoralis Major, Lattismus dorsi, teres major Extension: infraspinatus, teres minor

CLASSIC PRESENTATION: Child presents with a constant pain right below his knee cap for the past year. It gets worse with with jumping or running. 1) What is a complication?

Osgood Schlatter disease is causes by inflammation of the apophysis specifically the tibial tubercle which is the secondary ossification site of the knee. This can happen when during growth spurts when there is increasing tension the patellar ligaments inserting on the tibial tubercle. This makes it more painful to extend knee (jumping). COMPLICATION: Overuse of the quadriceps (leg extension at the knee) in adolescents can make the inflammed tubercle prone to fracture. Will present as fragmented and elevated tibial tubercle.

ANATOMY: 1) What separates the greater sciatic foramen from the lesser sciatic foramen? 2) What goes through the greater sciatic foramen? What muscle can hypertrophy to cause compression of other structures? 3) Where does that muscle originate and insert?

Sacrospinous ligament seperates the greater and lesser sciatic foramen. 1) Through the sciatic foramen: - Piriformis Muscle (Origin: anterior aspect of sacrum, Insert: greater trochanter of the femur) - Sciatic Nerve - Inferior gluteal vessels - Inferior pudendal vessels ***Hypertrophy of the piriformis can cause sciatic nerve compression.

ANATOMY: 1) What motion does the patella assist in? 2) What ligament is attached to this bone? Where else does it insert? 3) What tendon?

Patella sits on top of the knee joint and protects the joint. 1) MOTION: It helps with knee extension. 2) Patellar Ligament is attached to the anterior surface of the tibia. 3) Quadriceps tendon is on the superior part of the patella and inserts on the TIBIAL TUBEROSITY. 4) Injury causes inability to extend the knee. You should be able to feel the gap in their knee.

CLASSIC PRESENTATION: Patient had a large weight fall on her lower legs and hear a crack. On exam she is unable to extend her leg under resistance.

Patellar fracture since the patella transmitts tensile strength from the upper leg to the lower leg. Unable to mantain strength.

CLASSIC PRESENTATION: Patient with a PSH of CABG complains of a burning sensation in the skin of their medial foot. 1) What is this a branch of?

Saphenous nerve injury can happen when harvesting the saphenous vein (PSH of CABG). Branch of the femoral nerve.

ANATOMY: Which is the 5th finger?

Pinky

NERVE: Damage to the piriform recess would cause damage to which nerve and impair which reflex? What is the piriform for?

Piriform recess are cavities next to the epiglottis. The Internal Branch of the Recurrent Laryngeal lies inside the piriform recess under the overlying mucosal layer. It gives sensory info from the mucosa superior to the vocal cords and is important for the cough reflex.

CLASSIC PRESENTATION: Patient is having trouble with internal rotation and abduction of the hip. MRI shows compression of structures going through the greater sciatic foramen.

Piriformis syndrome is when piriformis hypertrophies and compresses the sciatic nerve.

CLASSIC PRESENTATION: Person who was in car accident has the car dashboard shoved into her knee and pushed her knee back. Her knee is swollen and bruised. Her lower leg also appears laxily connected to her upper leg. 1) What structures are vulnerable to injury?

Posterior Cruciate Ligament Tear Positive posterior drawer test 1) Structures of the POPLITEAL FOSSA are at risk for injury (popliteal artery).

CLASSIC PRESENTATION: Patient presents with progressive right hand weakness. She has preserved sensation of upper limbs but is unable to extend her finger and thumbs. 1) What muscle does this nerve lie btw?

Posterior intersooseus nerve compression, deep branch of the RADIAL NERVE innervates the muscles in finger and thumb extension. The superficial branch is what gives sensation. This nerve can runs under the SUPINATOR MUSCLE so can be compressed from excessive arm supination and pronation.

CLASSIC PRESENTATION: A sidewalk painter comes to office with knee pain. There is sharp localized pain on palpation. Passive ROM is normal but there's a lot of pain when walking on climbing on the exam table. 1) What lies posterior to the affected structure?

Prepatellar bursitis is from inflammation of the bursa btw the skin and the patella. It's supposed to help alleviate pressure but constant pressure on the bursa (kneeling a lot) can cause injury and inflammation. - Passive ROM is normal bc you're not putting any pressure. Active ROM is worse,

CLASSIC PRESENTATION: Elderly man slipped on ice and fractured his arm. He can't abduct his shoulder and has decreased sensation of his shoulder. 1) What artery and nerve and vulnerable to injury? 2) What is a complication?

Proximal humerus injury is a common injury in elderly and can cause injury to the axillary nerve and also cause avascular necrosis from damage to the humeral circumflex artery. Since this supplies retrograde flow.

NERVE: 1) What muscle does the radial nerve innervate? 2) What artery does it run alongside?

The radial nerve from the posterior cord and C5- T1 innervates the 1) MOTOR: Forearm extensors at the elbow (Triceps) - Extensor muscles at the forearm - Hand EXTENSORS at the wrist (Extensor) --> Lesion will cause a wrist drop 3) Brachioradialis 4) Extrinsic muscles of the digits 5) Supinator muscles SENSORY: Back of hand and forearm Runs alongside the Deep brachial artery (branch of the brachial artery)

CLASSIC PRESENTATION: Patient was cut on her hand on the palmar side. Patient is now unable to move her thumb, but still has sensation to all her fingers.

Recurrent Branch of the median nerve is much more distal and superfical and only has motor innervations.

CLASSIC PRESENTATION: Patient was weight-lifting and then experience acute back pain that radiates to the right posterior thigh all the way to the foot. Straight leg raise test is positive and hip extension is weaker. 1) What DTR to you expect to be absent?

S1 radiculopathy is most common herniated nerve root in sciatica that causes loss of sensation to the BACK of the foot. This will cause denervation of: 1) Gluteus maximus - Can't hip extend 2) Hamstrings - Can't knee flex 3) Gastrocnemius - Can't plantar flex Will also lose the Achilles DTR

CLASSIC PRESENTATION: Elderly man slipped on eye and fell on his outstretch hand. He has only mild swelling and tenderness at his dorsal wrist btw his extensor pollicis longus and extensor pollicis brevis. 1) What complication does he risk? 2) Which arterial flow will be compromised?

Scaphoid fracture is the MOST common hand fracture and presents as tenderness in the anatomic snuff box, pain under in the shallow triangular depression. Scaphoid makes up the floor of this triangle. 1) Avascular necrosis: from interruption of the RADIAL ARTERY because the artery supplies retrograde blood flow to the bones to the right of the scaphoid. This can result in NONUNION of the bone

MUSCLE: Which muscles would you have to go through to insert a thoracentesis at the MIDAXILLARY LINE? 1) What is the role of this muscle? 2) What nerve innervates it? 3) What happens when you damage this nerve?

Serratus anterior orginates on the first 8 ribs and inserts on the scapula. It rotates the scapula upwards and is innervated by the long thoracic nerve. Damage to it causes WINGED SCAPULA (raising arms causes medial border of the right scapula to lift off the thoracic wall and cause it to become prominent).

PATHOPHYSIOLOGY: How does lumbar radiculopathy caused by Spondylosis differ from radiculopathy caused by Disc Herniation?

Spondylosis is osteophyte formation of the vertabrae from degenerative changes, so the nerve affected is always the one right below. Vertebral disc herniation can affect the nerve right below OR a nerve even lower. A lateral hernation will affect the nerve below the vertabrae, but a central herniation can affect nerves lower, because the cauda equina passes over it.

CLASSIC PRESENTATION: Patient presents with localized pain above the acromion that gets worse when doing overhead activities. On exam, she can only abduct her arms 90 without feeling pain. She has 5/5 strength and there is no impingement sign. 1) What do you see on MRI?

Subacromial bursitis is inflammation of the bursa btw the acromion and the deltoid and head of humerus. 1) MRI: will show calcification on the supraspinatus tendinitis

CLASSIC PRESENTATION: Child fell on his outstretched arm after he was walking causing fracture right above the condyle of his humerus. Radial pulse is diminished. 1) What artery and nerve are prone to injury? 2) What if her radial pulse was normal?

Supracondylar Fracture is the MOST common fracture in kids. Can cause injury to the brachial artery and the median nerve because they run right down the middle of the humerus and are damaged during ANTERIOMEDIAL DISPLACEMENT of the bone relative to head. (Radial and Ulnar nerve branches of the median nerve might also be injured but less likely). 1) Forearm is supinated 2) Ulnar deviation of the wrist (only happens at a PROXIMAL LESION) 3) If her pulse is normal, then fracture was probably ANTERIOLATERAL, which means the RADIAL NERVE was injured.

CLASSIC PRESENTATION: Runner complains of knee pain.

Suprapatellar bursitis is from inflammation of the suprapatellar bursa btw the distal femur head and the quadriceps, can get damaged from overworking of the quadriceps.

CLASSIC PRESENTATION: Patient presents with localized pain above the acormion. Patient is asked to abduct his arm out 90 and with his thumbs facing down. When applying downward pressure, patient feels pain and has right sided weakness. 1) What is the role of the muscle? 2) What tests can you use?

Supraspinatus tendon impingment in Rotator Cuff Syndrome . Muscle runs above the scapula is btw the head of humerus and acromion and prone to injury (tight space) Innervated by the SUPRASCAPULAR NERVE Supraspinatus is important for the first 10-15 degrees of arm abduction (deltoid does the rest) DIAGNOSIS: 1) Empty can test (thumbs up and 90 arms)

HEAD & NECK: During normal swallowing: 1) How does the larynx move? 2) Epiglottis move? 3) Vocal Cords?

Swallowing requires blocking the airway to prevent aspiration: 1) Larynx moves superior and then anterior to the base of the tongue to push food into the posterior esophagus 2) Epiglottis is tilted to block airway 3) Vocal folds are adducted

NERVE: Sympathetic NS 1) What is the stellate ganglion? 2) Superior cervical ganglion? 3) Thoracic sympathetic trunk? 4) Thoracic sphlanchnic nerves?

Sympathetic innervations of the body: 1) Cervical sympathetic ganglion: sympathetic innervation of the head, neck, tarsal muscle, lacrimal gland, iris, salivary gland 2) Stellate ganglion (Cervicothoracic ganglion): hands 3) Thoracic Sympathetic trunk: axilla 4) Greater, lesser, and least thoracic splanchnic nerves: innervates all the abdominal viscera

NERVE: Which muscles are responsible for the range of pitch to our voice (denervation can cause hoarseness)? 1) What artery accompanies the external laryngeal nerve? 2) What artery accompanies the internal laryngeal nerve?

These muscles are all innervated by branches of CN10. 1) Superior larygneal nerve divides into 2 branches: - Cricothyroid muscle tenses the vocal cords and is innervated by the EXTERNAL laryngeal nerve running with the superior laryngeal artery - The internal larygneal branch is important for sensory info of the floor or the piriform recess and membrane of the larynx above the vocal folds running with the superior thyroid artery Recurrent laryngeal innervates the rest of the intrinsic muscles of the larynx.

NERVE: Thoracic Nerve 1) Where does it come from?

Thoracic Nerve (C5-C7) innervates the serratus anterior which holds the scapula to the back. Injury causes winged scapula.

CLASSIC PRESENTATION: Swimmer presents with tingling and numbess in the right shoulder, arm, and hand. He also has a dull pain in his right little finger and hand. Gets worse everytime he tries to swim. On exam, he has right sided weakness in the intrinsic muscles. He has no other past history, expect was born with an extra rib. 1) What muscles are causing? 2) What vessels might be involved? 3) What predisposes?

Thoracic outlet syndrome is caused by compression of the brachial plexus leading to upper extremity numbess, tingling, and weakness. This can be caused by compression by the SCALENE MUSCLES which the plexus passes through. Causes Klumpkle palsy 1) Can also involve the subclavian arteries and vessels and cause a swollen arm or weakened pulse and arm ischemia 2) Predisposed by scalene muscle abnormalities or extra ribs at the 7TH CERVICAL VERTEBRAE can cause compression of the scalene muscles

Which 3 muscles make up the Triceps surae muscle? What tendon is important for holding these structures? What happens in avulsion of this tendon?

Triceps surea is made of the 2 heads of the Gastrocnemius, soleus, and plantaris. Held in place by the Achilles tendon. Rupture of this tendon causes inability to plantar flex.

NERVE: Ulnar Nerve 1) What muscles does it innervate? 2) What nerve roots does it come from?

Ulnar nerve (C8-T1) runs thru GUYON'S CANAL which runs above the transverse carpal ligament. Roof of canal is the palmar fascia. 1) Muscles: - Interossei of the finger (DORSAL side- abduction and PALMAR side - adduction of fingers) - Hypothenar muscles and medial lumbricals (pinky motion) - Flexor Digotum Profundus of the ring finger and pinky (the distal interphalangeal joint) 2) Sensory loss: 1.5 finger at the pinky

CLASSIC PRESENTATION: Patient presents with diminished sensation of the dorsomedial hand, medial palm, fifth digit and medial 1/2 of fourth digit. They are also unable to flex the distal interphalangeal joint of their ring finger. 1) Where else can there be compression? 3) What muscles does this innervate? What motion? 3) Where does the wrist deviate towards if this nerve was proximally lacerated?

Ulnar nerve compression happening at the OLECRANON and the MEDIAL EPICONDYLE of the humerus (i.e. the cubital tunnel). 1) Also compression at the flexor carpi ulnaris and flexor digitorum profundus, in the GUYON CANAL (btw the hook of hamate and pisiform) 1) Innervates the flexor carpi radialis which helps with wrist abduction and flexion 2) Innervates intrinsic hand muscles --> Atrophy causes ulnar claw 3) Innervates the hypothenar eminence (pinky side) --> can be flat from atrophy 4) Wrist deviates towards the radial side bc you lose the flexors on the pinky side only if you have a PROXIMAL LACERATION (Medial epicondyle fracture)

CLASSIC PRESENTATION: Child broke her arm and has a fracture on the medial epicondyle. 1) What nerve is injured?

Ulnar nerve runs along the medical epicondyle.