Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Human Anatomy ppt lectures Topic 22 Ulnar Nerve And Its Lesions Notes. - anatomy ppt free download human anatomy ppt lectures, medicine notes ppt, anatomy handwritten notes pdf, mbbs 1st year anatomy notes pdf download, best anatomy notes pdf, human anatomy notes pdf, anatomy easy notes pdf, anatomy notes online, anatomy short notes, Anatomy ppt, Powerpoint Presentations and lecture notes.
ULNAR NERVE ANATOMY & Its LESIONS
Dr Mukesh Singla
Learning Objectives
1. Ulnar nerve formation , root value and important
relations
2. Motor and sensory supply
3. Important sites of injuries/entrapment of nerve
4. Effects of injury of ulnar nerve
5. How to clinically test ulnar nerve injury
Ulnar nerve C8T1
Origin : medial cord of
brachial plexus , runs medial
to brachial artery - middle of
arm.
At coracobrachialis insertion, -
pierces medial intermuscular
septum, is accompanied by
superior ulnar col ateral
artery ? and enter posterior
compartment of arm.
At elbow - posterior to
medial epicondyle.
No branches in arm.
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Ulnar nerve in forearm
? It continues downward
to enter in forearm
? b/w two heads of
flexor carpi ulnaris.
Passes through CUBITAL
TUNNEL
? It runs down forearm
between FCU and FDP.
? In lower half of forearm
it lies medial to ulnar
artery.
31
Cubital Tunnel
Cubital tunnel is a space of dorsal medial
elbow which allows passage of the ulnar
nerve around the elbow.
It is bordered
Medially - medial epicondyle of the
humerus,
laterally -olecranon process of the ulna and
tendinous arch joining the humeral and ulnar
heads of the flexor carpi ulnaris.
Cubital Tunnel
? Flexor carpi ulnaris.
Ulnar nerve in Forearm
? Medial ? of FDP
? Articular: elbow joint.
? Dorsal or posterior
cutaneous branch:
? Dorsal surface - medial
1/3rd of hand 1? fingers.
? Palmar cutaneous branch :
to supply skin of palm of
hand and medial 1? fingers.
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Ulnar nerve in Hand
33
Ulnar nerve in Hand
After it travels down the ulna, ulnar nerve enters the
palm of the hand.
At the wrist, the ulnar nerve and artery lie in a canal
formed by the pisiform bone medial y and the hook of
hamate lateral y (Guyon's canal).
In this region the nerve divides into two branches.
The Superficial sensory Branch
The Deep Motor Branch
Ulnar nerve in Hand
The superficial branch is general y considered a
sensory branch which supplies to distal palm, fifth and
half of the fourth digit.
It also supplies palmaris brevis, a thin muscle beneath
the skin which cannot be studied electromyographically.
The deep branch gives of motor innervation to the hand
muscles.
WRIST TO (MEDIAL) HAND
Ulnar nerve in Hand
Deep branch:
? Runs b/w abductor digiti minimi & flexor digiti minimi.
? pierces opponens digiti minimi.
? Then passes laterally within concavity of deep palmar
arch.
? lies deep to flexor tendons.
? It supplies 14 muscles :
? Three hypothenar muscles.
? Adductor policis.
? Al dorsal & palmar interossei.
? Medial 2 lumbricals.
35
BRANCHES: Muscular
FCU, FDP (medial half), palmaris brevis, hypothenar
muscles, medial 2 lumbricals, all palmar & dorsal
interossei , thumb intrinsics medial to FPL {adductor
pollicis , flexor pollicis brevis (deep head)}
Cutaneous
palmar cutaneous supply to hypothenar eminence
Dorsal cutaneous supply dorsum of hand (medial part),
dorsum of little finger , part of dorsum of ring finger.
Digital
forms the main sensory branches to the ring and little
finger
Vascular & Articular
No branches above elbow
DORSAL CUTANEOUS BRANCH
PALMAR CUTANEOUS BRANCH
Guyon Canal or Tunnel
Semi-rigid longitudinal canal in the wrist that allows passage of
the ulnar artery and ulnar nerve into the hand.
Roof of the canal -superficial palmar carpal ligament,
deeper flexor retinaculum and hypothenar muscles comprise the
floor.
The space is medially bounded by the pisiform and pisohamate
ligament more proximally, and laterally bounded by the hook of the
hamate more distally.It is approximately 4 cm long, beginning
proximally at the transverse carpal ligament and ending at the
aponeurotic arch of the hypothenar muscles.
Lesion of ulnar nerve above elbow - atrophy of
hypothenar muscles
Lesion of ulnar nerve above elbow
? Weakness of flexion at wrist paralysis of FCU
? Loss of flexion of terminal phalanges of ring & little
fingers paralysis of medial ? of FDP
? Paralysis of al interossei & medial 2 lumbricals (3rd &
4th).
? Characteristic deformity is - partial claw hand.
? Atrophy of hypothenar muscles.
? Fingers - hyperextended at metacarpophalangeal joints
& flexed at interphalangeal joints - ring & little finger.
? Loss of adduction of hand & thumb due to paralysis of
flexor carpi ulnaris & adductor pollicis.
Lesion of ulnar
nerve above
elbow - Loss of
cutaneous sensations
on front & dorsum of
medial 1/3 of hand +
medial 1 ? fingers.
? It leads to paralysis of
Lesion of ulnar
intrinsic muscles of hand as
nerve above
described above.
wrist
? deformity `claw hand'
? Loss of cutaneous sensations
of medial 1 ? fingers.
Test for Palmar interossei
Test for adductor &
for adduction of fingers.
opponens pollicis.
Test for Palmar interossei for
Test for adductor &
adduction of fingers.
opponens pol icis.
Ulnar Nerve Injuries
most commonly injured @
At elbow
where it lies behind the medial epicondyle usually associated with
fracture
At wrist
where it lies with the ulnar artery in front of the flexor retinaculum.
Injuries to the Ulnar Nerve at the Elbow
CUBITAL TUNNEL SYNDROME (2ND most common)
Motor
Flexor carpi ulnaris & medial half of flexor digitorum profundus
ring & little fingers
No flexion of the terminal phalanges of the ring & little fingers
Flexion of wrist = abduction paralysis of flexor carpi ulnaris
medial border of the front of the forearm flattned/wasted
Al the smal muscles of the hand paralyzed EXCEPT ?
Injuries to the Ulnar Nerve @ the Elbow
Motor
Extensor digitorum can abduct the fingers to a small extent
when metacarpophalangeal joints are hyperextended
Impossible to adduct the thumb adductor pol icis paralyzed
Froment's sign
Grip a piece of paper between the thumb and index fingers
Froment sign: The patient is asked to hold the paper between the thumb and index finger.
(A) With the intact ulnar nerve, the patient is able to make use of the adductor pol icis. ( B)
When the ulnar nerve is deficient, the patient compensates for the denervated adductor by
using the flexor pol icis longus (median nerve innervated).
Injuries to the Ulnar Nerve @ the Elbow
Motor
2 medial lumbricals & interossei Hyperextended metacarpophalangeal joints
Flexed interphalangeal joints
fourth & fifth fingers
"claw" deformity main en griffe
Injuries to the Ulnar Nerve @ the Elbow
Motor
Flattening of hypothenar eminence
Loss of the convex curve to the medial border of the hand
Holowing between metacarpal bones @ dorsum of the hand
wasting of dorsal interossei
Injuries to the Ulnar Nerve @ the Elbow
Sensory
Loss of skin sensation
anterior & posterior surfaces of medial 1/3 of the hand
medial 1 ? fingers
Vasomotor Changes
warmer and drier skin area
arteriolar dilatation and absence of sweating /loss of sympathetic control
Injuries to the Ulnar Nerve @ the Wrist
Motor
Smal hand muscles paralyzed, wasted ? EXCEPT 3 thenar @ first 2 lumbricals
Claw hand
More obvious
Flexor digitorum profundus intact
Marked flexion of the terminal phalanges
Ulnar paradox
Higher lesion
Less obvious claw deformity
More proximal injury
Less claw
ULNAR NERVE ENTRAPMENT SYNDROMES
PROXIMAL/ @ ELBOW
CUBITAL TUNNEL SYNDROME
BETWEEN MEDIAL EPICONDYLE & FLEXOR CARPI ULNARIS
Q: Medial half of Flexor digitorum profundus
DISTAL/ @ WRIST
affected in which one most?
GUYON'S CANAL Roof: Palmaris brevis, hamate,pisiforme bones & FCU
Froment's sign
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.[2]
Froment's sign : hyperflexion of IP jt of thumb
while attempting a lateral pinch(indicates
paralysis of adductor pollicis, 1st DI , with
replacement of pinch function by FPL)
Ulnar paradoxus
In proximal ulnar lesion (closer to the elbow), the Flexor
Digitorum Profundus may also be denervated. As a result,
flexion of the Interphalangeal joints is weakened, which
reduces the claw-like appearance of the hand.
In distal lesion, at or below wrist
Condition of claw hand is worse because as FDP is spared
,there is active flexion of interphalangeal joint of medial two
digits.This is called the "ulnar paradox" because one would
normally expect a more debilitating injury to result in a more
deformed appearance.
Cross your fingers test:
Inability to cross the middle finger dorsally over the index
finger or vise versa.(1st PI & 2nd DI)
Some Facts
? At the back of medial epicondyle, ulnar nerve is lodged in a
groove.
? Pressure on nerve at this site produce " funny bone
,symptoms with tingling along hypothenar eminence and
little finger
Some Facts
? Deep branch of ulnar nerve is called "musician" nerve
because it innervates all the small muscles of hand involved
in fine movement
? Median nerve- eye of hand because it supply sensory
receptors in the tips of medial three and half fingers of hand
? Median nerve ? laborer's nerve because of motor supply to
long flexor tendons
which of these symptoms is not caused by damage to the
median nerve at the wrist?
A
ape/simian hand
B
loss of pronation
C
loss of sensation in most of thumb and digits 2 and 3.
D
thenar muscle paralysis
which of these symptoms is not caused by damage to the
median nerve at the wrist?
A
ape/simian hand
B
loss of pronation
C
loss of sensation in most of thumb and digits 2 and 3.
D
thenar muscle paralysis
? Injury to the ulnar nerve at the ____ causes ______, and at
the ____ causes ____
? A
? elbow, radial deviation, wrist, wrist drop
? B
? elbow, radial wrist deviation, wrist, severe clawing of hand
? C
? elbow, severe clawing of hand, wrist, radial deviation
? D
? elbow, wrist drop, wrist, radial deviation
? Injury to the ulnar nerve at the ____ causes ______, and at
the ____ causes ____
? A
? elbow, radial deviation, wrist, wrist drop
? B
? elbow, radial wrist deviation, wrist, severe clawing of hand
? C
? elbow, severe clawing of hand, wrist, radial deviation
? D
? elbow, wrist drop, wrist, radial deviation
? A patient after injury on hand presents with hand in claw
position with 4th and 5th fingers extended at the
metacarpophalangeal joints and flexed at the
interphalangeal joints. Which nerve is involved in this injury
? Radial nerve
? Median nerve
? Ulnar nerve
? Anterior interosseous nerve
? A patient after injury on hand presents with hand in claw
position with 4th and 5th fingers extended at the
metacarpophalangeal joints and flexed at the
interphalangeal joints. Which nerve is involved in this injury
? Radial nerve
? Median nerve
? Ulnar nerve
? Anterior interosseous nerve
2.
Froment's sign is used to
test the strength of which muscle
a)
Abductor Pollicis longus
b)
Adductor Pollicis
c)
Flexor Pollicis longus
d)
Extensor Pollicis Longus
Froment's sign is used to test the strength of
which muscle
a) Abductor Pollicis longus
b) Adductor Pollicis
c) Flexor Pollicis longus
d) Extensor Pollicis Longus
? A patient is asked by his physician to hold their wrist in
complete and forced flexion (pushing the dorsal surfaces of
both hands together) for 30?60 seconds. This maneuver
compress the nerve within the carpal tunnel and
characteristic symptoms (such as burning, tingling or numb
sensation over the thumb, index, middle and ring fingers)
conveys a positive test result and suggests carpal tunnel
syndrome. What is the name of manoeuvre physician is
performing
? Turning Circle maneure
? Phalen's Manoeuvre
? Collision Avoidance Manoeuvre
? Zig-zag Test Manoeuvre.
1. A patient is asked by his physician to hold their wrist in
complete and forced flexion (pushing the dorsal surfaces of
both hands together) for 30?60 seconds. This maneuver
compress the nerve within the carpal tunnel and
characteristic symptoms (such as burning, tingling or numb
sensation over the thumb, index, middle and ring fingers)
conveys a positive test result and suggests carpal tunnel
syndrome. What is the name of manoeuvre physician is
performing
a) Turning Circle maneure
b) Phalen's Manoeuvre
c) Collision Avoidance Manoeuvre
d) Zig-zag Test Manoeuvre.
?
A clinical condition in which patient shows inability to
abduct the thumb due to median nerve lesion is called
? a. Pollock `s Sign
? b. Pointing Index
? c. Ape thumb deformity
? d. Andre- Thomas Sign
A clinical condition in which patient shows inability to abduct
the thumb due to median nerve lesion is called
a. Pollock `s Sign
b. Pointing Index
c. Ape thumb deformity
d. Andre- Thomas Sign
The index finger is not flexed at the proximal
interphalangeal (PIP) and distal interphalangeal (DIP)
joints. This clinical condition is called pointing index. This
condition is due to lesion of
a)
Ulnar nerve
b)
Median nerve
c)
Radial nerve
d)
Posterior interosseous nerve
The index finger is not flexed at the proximal interphalangeal
(PIP) and distal interphalangeal (DIP) joints. This clinical
condition is called pointing index. This condition is due to
lesion of
a)
Ulnar nerve
b)
Median nerve
c)
Radial nerve
d)
Posterior interosseous nerve
Pen test in hand is performed to assess the
neuromuscular status of:
a)
Opponens pollicis
b)
Flexor pollicis brevis
c)
Abductor pollicis brevis
d)
First palmar interossei
Pen test in hand is performed to assess the neuromuscular
status of:
a) Opponens pollicis
b) Flexor pollicis brevis
c) Abductor pollicis brevis
d) First palmar interossei
In the phalen's test, the suspected compression of
median nerve is elicited. Which of the following are the other
structures passing through the carpal tunnel?
? a. Ulnar nerve
? b. Superficial cutaneous branch
? c. Flexor digitorum profundud tendons
? d. Palmaris longus tendon
In the phalen's test, the suspected compression of median
nerve is elicited. Which of the following are the other
structures passing through the carpal tunnel?
a. Ulnar nerve
b. Superficial cutaneous branch
c. Flexor digitorum profundud tendons
d. Palmaris longus tendon
This post was last modified on 05 April 2022