MSK Flashcards
Erb Palsy
Which injury?
What causes the injury?
What is the muscular deficit?
How does it present?
Which injury?
- Traction or tear of upper (“Erb-er”) trunk: C5-C6 roots
What causes the injury?
Infants—lateral traction on neck during delivery
Adults—trauma
What is the muscular deficit?
Deltoid, supraspinatus, Infraspinatus, Biceps brachii
How does it present?
Waiter’s tip
What are the bones of the wrist?
Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium
What are the rotator cuff muscles and what are their actions?
Supraspinatus - abduction
Infraspinatus - externally rotates
Teres minor - adducts and externally rotates
Subscapularis - internally rotates and adducts arm
Which nerve innervates the hypothenar eminence?
ulnar nerve
Musculocutaneous
What is the nerve root?
What is the cause of injury?
How does injury present?
What is the nerve root?
(C5-C7)
What is the cause of injury?
Upper trunk compression
How does injury present?
Loss of forearm flexion and supination
Loss of sensation over lateral forearm
Recurrent branch of median nerve
What is the nerve root?
What is the cause of injury?
How does injury present?
What is the nerve root?
C5-T1
What is the cause of injury?
Superficial laceration of palm
How does injury present?
- “Ape hand”
- Loss of thenar muscle group: opposition, abduction, and flexion of thumb
- No loss of sensation
What is carpal tunnel syndrome?
Entrapment of median nerve in carpal tunnel
Thenar eminence atrophies but sensation spared, because palmar cutaneous branch enters hand external to carpal tunnel.
What is a Baker cyst?
Popliteal fluid collection
Median
What is the nerve root?
What is the cause of injury?
How does injury present?
What is the nerve root?
C5-T1
What is the cause of injury?
- Supracondylar fracture of humerus (proximal lesion)
- Carpal tunnel syndrome and wrist laceration
How does injury present?
- “Ape hand” and “Pope’s blessing”
- Loss of wrist flexion, flexion of lateral fingers, thumb opposition, lumbricals of 2nd and 3rd digits
- Loss of sensation over thenar eminence
What are the muscles of the hypothenar eminence?
Opponens digiti minimi
Abductor digiti minimi
Flexor digiti minimi brevis
Obturator
What is the nerve root?
What does it innervate?
How is it commonly injured?
How does the injury present?
What is the nerve root?
L2-L4
What does it innervate?
Sensory—medial thigh
Motor—obturator externus, adductor longus, adductor brevis, gracilis, pectineus, adductor magnus
How is it commonly injured?
Pelvic surgery
How does the injury present?
decreased thigh sensation (medial) and adduction
Ulnar
What is the nerve root?
What is the cause of injury?
How does injury present?
What is the nerve root?
C8-T1
What is the cause of injury?
- Fracture of medial epicondyle of humerus “funny bone” (proximal lesion)
- Fractured hook of hamate (distal lesion) from fall on outstretched hand
How does injury present?
- “Ulnar claw” on digit extension
- Radial deviation of wrist upon flexion (proximal lesion)
- Loss of wrist flexion, flexion of medial fingers abduction and adduction of fingers (interossei),
- Loss of sensation over medial 11/2 fingers including hypothenar eminence
Extensors of the hip
Gluteus maximus
Semitendinosus
Semimembranosus
Lateral femoral cutaneous
What is the nerve root?
What does it innervate?
How is it commonly injured?
How does the injury present?
What is the nerve root?
L2-L3
What does it innervate?
Sensory—anterior and lateral thigh
How is it commonly injured?
Tight clothing, obesity, pregnancy, pelvic procedures
How does the injury present?
decreased thigh sensation (anterior and lateral)
Thoracic outlet syndrome
Which injury?
What causes the injury?
What is the muscular deficit?
How does it present?
Which injury?
Compression of lower trunk and subclavian vessels
What causes the injury?
Cervical rib fracture, Pancoast tumor
What is the muscular deficit?
Same as Klumpke
How does it present?
Atrophy of intrinsic hand muscles; ischemia, pain, and edema due to vascular compression
Tibial
What is the nerve root?
What does it innervate?
How is it commonly injured?
How does the injury present?
What is the nerve root?
L4-S3
What does it innervate?
Sensory—sole of foot Motor—biceps femoris (long head), triceps surae, plantaris, popliteus, flexor muscles of foot
How is it commonly injured?
Knee trauma, Baker cyst
How does the injury present?
TIP = Tibial Inverts and Plantarflexes; if injured, can’t stand on TIPtoes Inability to curl toes and loss of
Abductors of the hip
Gluteus medius
Gluteus minimus
What causes abnormal passive adduction of the knee?
Knee either extended or at ~ 30° angle, medial (varus) force lateral space widening of tibia
LCL injury.
Genitofemoral nerve
What is the nerve root?
What does it innervate?
How is it commonly injured?
How does the injury present?
What is the nerve root?
(L1-L2)
What does it innervate?
Sensory—scrotum/labia majora, medial thigh
Motor—cremaster
How is it commonly injured?
Laparoscopic surgery
How does the injury present?
- decreased anterior thigh sensation
- absent cremasteric reflex