Nerve/Artery Damage

Question 1

Pudendal Nerve

Answer 1

S2-S4 (near ischial spine)
innervation to perineum and genitals
Motor innervation to sphincter urethra and external anal sphincter
Relive pain during delivery

Question 2

Medial Circumflex Artery

Answer 2

Femoral Head Necrosis

Question 3

Erb Palsy

Answer 3

Injury: traction or tear of upper trunk (C5-C6 roots)

Causes: infants-lateral traction on neck during delivery
Adults-violent stretch between head and shoulder

Muscles involved:
Deltoid, supraspinatus-abduction
Infraspinatus-lateral rotation
Biceps brachi-flexion supination
Therefore patient presents with shoulder adducted, arm pronated and elbow extended

Question 4

Klumpke Palsy

Answer 4

Injury: Traction or tear of lower trunk (C8-T1 root)

Causes: infants upward force on arm during delivery
Adults-trauma (grabbing a tree branch as falling)

Muscles:
Intrinsic hand muscles, lumbricals (normally flex MCP and extend DIPs and PIPS), interossei, thenar, hypothenar

Defecit: total claw hand

Question 5

Thoracic Outlet Syndrome

Answer 5

Injury: Compression lower trunk and subclavian vessels

Causes: cervical rib injury
Pancoast tumor

Muscle deficit: Intrinsic hand muscles, lumbricals (normally flex MCP and extend DIPs and PIPS), interossei, thenar, hypothenar

Symptoms: atrophy of intrinsic hand muscles, ischemia, pain and edema

Question 6

Winged scapula

Answer 6

Injury: lesion of long thoracic nerve

Causes: axillary node dissection after mastectomy
Stabs

Muscle: serratus anterior

Symptoms: inability to anchor scapula to thoracic cage
Cannot abduct arm above horizontal position

Question 7

Axillary Nerve

Answer 7

(C5-C6)-Posterior Cord
Injury: Fractured surgical neck of humerus
Anterior dislocation of humerus

Innervates deltoid and teres minor

Presentation: flattened deltoid
Loss of arm abduction at shoulder (>15 degrees)
Loss of sensation over deltoid muscle and lateral arm

Question 8

Musculocutaneous Nerve

Answer 8

(C5-C7)-Lateral Cord
Injury: upper trunk compresion
Forceful injuries that cause separation of neck and shoulder
Courses directly between biceps brachii and coracobrachialis

Presentation: loss of forearm flexion and supination
Loss of sensation over lateral forearm

Question 9

Radial Nerve

Answer 9

(C5-T1) posterior cord
Injury: midshaft fracture of humerus
Compression of axilla (due to crutches or sleeping with arm over chair)
Courses through supinator muscle near head of radius

Travels with deep brachial artery

innervates: extensors, brachiradialis and supinator

Presentation: Wrist drop-loss of elbow, wrist and finger extension
decreased grip strength
Loss of sensation over posterior arm/forearm and dorsal hand

Question 10

Median nerve

Answer 10

C5-T1-Lateral and medial cords
Injury: supracondylar fracture of humerus (proximal)
carpal tunnel syndrome and wrist laceration (distal)
Suicide attempts

Courses between flexor digitorum and flexor digitorum profundus (in flexor retinaculum)

Courses with brachial artery between biceps brachii and brachialis

Claw of lateral fingers
Loss of wrist and lateral finger flexion, thumb opposition, lumbricals of 2nd and 3rd digits
Loss of sensation over thenar eminence and dorsal and palmar aspects of lateral 3.5 fingers with proximal lesion

Question 11

Recurrent Median nerve

Answer 11

laceration of palm
Injury: Limits finger abduction
Loss of thenar muscle group: opposition, abduction and flexion of thumb

Question 12

Ulnar

Answer 12

C8-T1 (lower trunk)
Injury: fracture of medial epicondyle of humerus (proximal)
Fractured hook of hamate (distal)

Courses between olecranon and medal epicondyle of humerus and between flexor carpi ulnaris and flexor digitorum profundus

claw of medial fingers
Radial deviation of wrist upon flexion (proximal)
Loss of flexion of wrist and medial fingers, abduction and adduction of fingers
Loss of sensation over medial 1.5 fingers including hypothenar eminence

Question 13

Obturator

Answer 13

L2-L4
Injury: pelvic surgery-lymph node dissectin
Exits via obturator foramen

Symptoms: decreased thigh sensation (medial) and decreased adduction

Question 14

Femoral

Answer 14

L2-L4
Injury: pelvic fracture or mass involving iliopsoas/iliacus

Symptoms: difficulty with stairs, knee wobbly
Decreased thigh flexion and leg extension
Decreased sensation of anterior aspect of thigh
Decreased patellar reflex
Weakness of quads

Question 15

Common peroneal/Common fibular

Answer 15

L4-S2 (PED-peroneal everts and dorsiflexes if injured foot dropPED)
Injury: trauma or compression of lateral aspect of leg, fibular neck fracture
External pressure due to surgery, casting or hospitilization

Presentation: foot drop-inverted plantarflexed at rest
Loss of eversion and dorsiflexion
Steppage gait-foot lifted high, foot slap
Loss of sensation on dorsum of foot

Question 16

Tibial

Answer 16

L4-S3 (TIP-tibial inverts and plantarflexes if injured can’t step on TIPtoes)
Injury: knee trauma, baker cyst (proximal), tarsal tunnel syndrome (distal)

Symptoms: inability to curl toes and loss of sensation on sole of foot
Proximal: foot everted and dorsiflexed at rest
Loss of inversion and plantar flexion
Involves calf, soleus and plantaris

Question 17

Superior Gluteal

Answer 17

L4-S1
Injury: posterior hip dislocation, polio

Symptoms: trandelenberg gait: pelvis tilts because weight berating leg cannot maintain alignment of pelvis through hip abduction (sup. nerve=medius and minimus)
Lesion is contralateral to side of hip that drops
Ipsilateral to side that patient stands

Proper placement of injection is superolateral quadrant (supermedial will result in trandelenberg)

Question 18

Inferior gluteal

Answer 18

L5-S1
Injury: posterior hip location

Symptoms: difficulty climbing stairs, rising from seated position
Loss of hip extension (inferior nerve=gluteus maximus)