Robertson: Putting It All Together Flashcards
What happens when you have C5/6 palsy?
absence of shoulder abduction and external rotation (axillary)
no elbow flexion (musculocutaneous)
What happens when you have damage to C5/6/7 ?
lack of wrist and finger extension (add in radial)
What happens when you have damage to C8/T1? What causes this?
intrinsic wasting of hand muscles; caused by a traction mechanism
What are some things that can occur as a result of a spinal avulsion (preganglionic lesion)
Horners (sympathetic chain)
Elevated hemi diaphragm (phrenic)
Winged scapula (long thoracic)
Absence of rhomboid (dorsal scapular)
How to you treat a spinal avulsion?
nerve/tendon transfers
What is the most common way to damage the radial nerve?
mid shaft fracture (radial nerve travels along the spiral groove of the humerus)
What should you ask your patient to do in order to check for radial nerve function?
give a thumbs up
**tests extensor pollicis longus
What are the first few muscles that recover following radial nerve damage?
extensor carpi radialis brevis
supinator
extensor carpi ulnaris
What are the last few muscles to recover following radial nerve damage?
extensor pollicis longus
extensor pollicis brevis
extensor indices
What is Saturday night palsy?
radial neuropathy caused by lying on the arm where the radial nerve spirals around the humerus (i.e. drunk at a bar)
4 key features of the claw hand
MP hyperextension
no finger abduction or adduction **loss of palmar/dorsal interossei
weak grip
lack of key pinch
What muscle of the thumb is responsible for key pinch?
adductor pollicis
Damage to the ulnar nerve causes intrinsic (blank) of the hand and the loss of the (blank) arch
wasting; palmar
3 signs to test for ulnar nerve damage
Fromont’s sign
Wartenberg’s sign
Bouvier’s maneuver
Explain Fromont’s sign to test for ulnar nerve damage. What muscle is this specifically testing?
To perform the test, a patient is asked to hold an object, usually a flat object such as a piece of paper, between their thumb and index finger (pinch grip). The examiner then attempts to pull the object out of the subject’s hands. This is testing adductor pollicis function.
a neurological sign consisting of abduction of the fifth finger, caused by unopposed ulnar insertion of the extensor digiti minimi
Wartenberg’s sign
What two muscles in the forearm does the ulnar nerve innervate?
FCU
2 digits of the flexor digitorum profundus *single muscle belly and tendon
What innervates the interossei in the hand? How many palmar interossei are there? What action do they perform? How many dorsal interossei? What action do they perform?
ulnar nerve; 3 palmar cause adduction; 4 dorsal cause abduction
**interossei cause flexion at MP and extension at PIP
The interossei attach (blank) to the axis of rotation at the MP joint, so they cause flexion. Their tendons pass (blank) to the axis of rotation at the PIP and DIP, so they cause extension at PIP/DIP.
anterior or palmer; dorsal
What muscle originates on a finger flexor and inserts onto a finger extensor?
lumbricals **originate from FDP and insert on extensor expansion (index through little finger)
This muscle passes palmer to axis of rotation at MP joint
Dorsal to axis of PIP joint
And has an origin and insertion into a tendon
lumbrical
What muscle are you testing for when assessing key pinch? Damage to what nerve causes this phenomenon?
adductor pollicis; ulnar nerve
So, list all of the muscles in the hand that have innervation by the ulnar nerve
adductor pollicis
hypothenar muscles: abductor digiti minimi** (main one in which you see disfunction), opponens digiti minimi, flexor digiti minimi brevis
ulnar lumbricals
dorsal and palmar interossei
How do you differentiate an ulnar nerve lesion at Guyon’s canal (wrist) vs the elbow?
If sensation over dorsum of wrist on ulnar side, the ulnar nerve is OK at the elbow (dorsal sensory branch leaves the ulnar nerve proximal to the wrist and goes unto dorsum of hand). Nerves that go through guyon’s canal just innervate the tips of fingers.
You can have ulnar nerve damage at several different locations. Mention a few. Which is most common?
C8-T1 root (disc)
Plexus (cervical rib, pancoast tumor)
Cubital tunnel **most common by far
Guyon’s canal
What are these associated with? Arcade of Struthers Intermuscular septum Medial head Tricep Anconeus Epitrochlearis Osborns Ligament Flexor Carpi Ulnaris
cubital tunnel and ulnar nerve entrapment
Where does ulnar nerve entrapment occur in the wrist?
Guyons canal
If you have a mixed motor and sensory problem, where has damage to the ulnar nerve occured?
proximal to the bifurcation of the ulnar nerve into superficial and deep branches
If you have MOTOR only problems, where has damage to the ulnar nerve occurred?
distal to the bifurcation into deep motor branch
If you have SENSORY only problems, where has damage to the ulnar nerve occurred?
distal to bifurcation into superficial
Upon clinical exam, you find the dorsal sensory innervation intact and isolated intrinsic weakness. Where has damage to the ulnar nerve occured?
at the wrist (after bifurcation into superficial)
Upon clinical examination, you find no dorsal sensory innervation, weakness in the ulnar flexors and intrinsic hand muscles, and elbow flexion reduces the symptoms. Where has damage to the ulnar nerve occured?
at the elbow
What muscle can get in the way of the ulnar nerve and cause irritation?
medial head of triceps
The anterior interosseous nerve is a branch of the median nerve. What 3 things does it specifically supply?
flexor pollicis longus
flexor digitorum profundus to the index
pronator quadratus
List all of the muscles innervated by the median nerve
Pronator teres, Flexor Carpi Radialis Flexor Digitorum Superficialis Flexor Digitorum Profundus (Index, Long) Palmaris longus
AIN:
Flexor Pollisis Longus
Flexor Digigorum Profundus Index
Pronator Quadratus
Hand: Thenar Muscles Abductor Pollicis Brevis Flexor Pollicis Brevis Opponens Pollicis
Where does the medial nerve enter into the forearm?
through the superficial and deep heads of the pronator teres
3 deep muscles of the forearm? What are these muscles innervated by?
flexor pollicis longus
flexor digitorum profundus
pronator quadratus;
the anterior interosseous nerve
What is the most commonly diagnosed entrapment of the upper extremity?
carpal tunnel syndrome
What are some symptoms of Carpal Tunnel Syndrome?
paresthesias and numbness aching pain in median nerve distribution (radial digits)
nocturnal symptoms (sleeping with flexed wrist)
worse with use
thenar wasting
Which muscles in the hand are innervated by the median nerve?
thenar muscles: opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
Contents of the carpal tunnel?
**test question
flexor digitorum superficialis tendons
flexor digitorum profundus tendons
flexor pollicis longus
median nerve
What is contained in Guyon’s canal? **test question
ulnar artery and nerve
What is the flexor retinaculum attached to laterally and medially?
laterally: scaphoid and trapezium
medially: hook of hamate and triquetrum
How to fix carpal tunnel syndrome?
carpal tunnel release (cut flexor retinaculum)
bracing
steroid injection
Is carpal tunnel caused by typing? What is it caused by?
No! It’s genetic.
What is this?
Painful catching locking with finger range of motion
Worse in am and after activity
Patients localize symptoms to PIP even though catching is occurring at MP joint)
trigger finger
Who is more likely to get trigger finger? Males or females? What are some risk factors? Is it associated with an increase in computer use?
females 2-6x rate of males
diabetes, gout, RA are risk factors (**lifetime incidence 2.2)
noooo
Flexor tendons run within a tight fibro osseous (blank). They can get irritated and swell within the sheath causing (blank) and pain.
tunnel (tendon sheath); catching
What is the purpose of the pulley system in the fingers?
The pulleys keep the tendon close to bone and maximize joint motion for given tendon excursion.
What is the relationship of FDP and FDS proximal to A1? Distal to A2?
Proximal to A1, the superficial tendon is superficial and the deep tendon is deep. Distal to A2, they are reversed, and the superficial tendon dives deep
What is campers Chiasma?
where the tendons of the FDS come back together deep to the FDP before inserting into the second phalanx
What are the critical pulleys? Release of these pulleys will cause (blank)
A2** and A4
bowstringing
The FDS lies (blank) to the FDP in the palm (proximal to A1) then splits and dives deep, around the FDP before coming back together at P1 aka (blank) deep to the FDP before inserting into the P2
superficial; Campers chiasma
2 things that pulley deficiency causes
bowstringing
lack of motion
What causes a mallet finger? What to you do to repair it?
avulsion of a terminal tendon from the distal phalanx; use a stack splint for 8 weeks
What can these cause? terminal tendon attenuation volar plate attenuation loss of FDS intrinsic tightness lateral band tightness dorsal skin tightness
swan neck
What is swan neck?
too much extension at the proximal joint and not enough at the distal
What causes a boutonniere deformity?
central slip disruption
volar migration of lateral bands
In a boutonniere deformity, the lateral band moves (blanker) to the axis of rotation of PIP
palmer
What are these? Sausage digit pain with passive extension pain along tendon sheath flexed resting posture
Kanavel’s sign: signs of infection in a tendon sheath, or septic tenosynovitis
What is this?
Midpalmer septum from 3rd metacarpal
thenar space
What is this?
Ulnar to midpalmer septum (3rd metacarpal)
midpalmar space
What is the terrible triad?
radial head fracture
coronoid fracture
elbow dislocation (lateral ulnar collateral disruption, medial ulnar collateral disruption)
What is this?
Provides varus stability
Resists posterlateral rotary instability
lateral ulnar collateral
What is this?
Provides valgus stability
medial ulnar collateral
What is the function of the rotator cuff muscles?
maintain glenohumeral relationship
deltoid provides motor for arm elevation
If there is a cyst at the suprascapular notch, what nerves will it affect?
the supraspinatus and infraspinatus
If there is a cyst at the spinoglenoid notch, what nerve will it affect?
only the infraspinatus
What type of displacement at the elbow does the coronoid resist? What about the radial head?
coronoid (ulna) resists posterior and posterior/medial displacement
radial head resists varus displacement
