2. ANATOMY OF ULNAR NERVE
A branch of medial cord of the brachial plexus
(C8 & T1). Additional fibers from C7.
Axilla : between axillary vein & artery on a deeper
plane.
runs downwards with proximal part of brachial
artery.
at middle of humerus pierces medial
intermuscular septum.
descends behind medial epicondyle.
3.
4.
5.
Forearm : enters by passing between two heads of
FCU.
lies on medial part of FDP.
accompanied by ulnar artery in lower 2/3 rd.
6.
7. After it travels down the ulna, the 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 medially and the hook of
hamate laterally (Guyon’s canal).
In this region the nerve divides into two branches.
The Superficial sensory Branch
The Deep Motor Branch
8. The superficial branch is generally 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 off motor innervation to the hand
muscles.
10. 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
14. CHARACTERISTICS OF PALSY
INJURIESproximal : motor - all muscles affected.
sensory - palmar & dorsal aspects of
medial third of hand, whole of little finger & ulnar
half of ring finger.
distal : motor - only intrinsic muscles involved
sensory - medial third of palm, palmar &
dorsal (distal to PIP joint) aspects of little & ulnar
half of ring finger
15. Injury to terminal deep branch in palm
Motor: spares hypothenar muscle
Sensory: sensation in ring & little finger preserved.
Compression in distal portion of guyon’s canal
Sensation (ring & little) intact
Loss of function of all ulnar innervated intrinsic &
hypothenar muscles.
In proximal portion of guyon’s canal
Preserved sensation over dorsal ulnar aspect of hand.
(by dorsal branch of ulnar nerve which arises in distal
forearm & perforates the deep fascia 6-8 cm proximal to
wrist)
LEPROSY
sensory changes precede motor paralysis
POLIOMYELITIS
LMN type flaccid paralysis
16. CLINICAL FEATURES
Claw deformity .
more apparent during use than at rest
more in mobile & lax fingers
When gripping an object , object is pushed out of the
palm (in order of DIP, PIP, MP joint flexion)
Wasting of hypothenar region & shallow mid-palmar
receptacle.
Longitudinal palmar furrows between long flexor
tendons.
Wasting of dorsum, with shallow concavities in intermetacarpal spaces & thumb web.
Shape of hand - Isosceles triangle with base distally.
Loss of sensation is not as devastating as compared
to median nerve palsy.
17. ASSESSMENT OF MOTOR FUNCTION
Duchenne’s sign : claw deformity of fingers ;
ulnar paradox
Bouvier’s maneuver: active extension of middle &
distal phalanges on passive dorsal pressure on
proximal phalanx.
Andre-Thomas sign : increased clawing on
attempted extension of fingers by flexing wrist.
18.
Pitres-Testut sign : inability to abduct extended
middle finger to radial & ulnar sides(2nd &3rd DI)
Cross your fingers test: Inability to cross the middle
finger dorsally over the index finger or vise
versa.(1st PI & 2nd DI)
Asynchronous finger flexion
Fingers curl or roll into palm & inefficient grasp
19.
Jeanne’s sign : Hyperextension of MP joint of thumb
during key pinch(to compensate thumb adductors)
Masse’s sign : flattened metacarpal arch & loss of
hypothenar elevation
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)
Bunnell’s O sign : hyper extension of MP jt & hyper
flexion of IP jt
20.
Wartenberg’s sign: inability to adduct extended little
finger to touch the extended ring finger(loss of
function of 3rd PI & unopposed abduction of EDM).
Pollock’s sign : inability to flex DIP jt of ring & little
fingers while making a fist
Partial loss of wrist flexion with inability to perform
power grip : Bowden & Napier
21. ASSESSMENT OF SENSORY FUNCTION
Static two point discrimination test (6 mm is
normal) for tactile perception.
Dynamic two point discrimination test (3 mm is
normal).
Semmes – Weinstein monofilament (of various
diameters) for pressure perception.
Tune fork 250 cps (pacinian corpuscles) , 30 cps
(meissner corpuscles) for vibration perception.
Cold heat test (10 degree, 40 degree water) for
free nerve endings of the skin.
Ten test (0- 10 ranking of quality of sensation)
22. ANOMALOUS INNERVATION PATTERNS
May contain axons from C7 & T2 roots.
Motor axons to FCU may arise from C7 root.
FDP innervation may be all ulnar/ all median/
combined.
Martin-Gruber anomalous motor connections in
proximal forearm between median(AIN) & ulnar
nerve.
Riche-Cannieu anomalous connections in hand,
resulting in all lumbricals supplied by median nerve &
no clawing even after complete ulnar nerve injury.
Ring finger lumbrical dual supply in 50%.
1st dorsal interosseous supplied by median nerve in
10% & radial nerve in 1%.
Area supplied by dorsal sensory branch may be
innervated by superficial branch of radial nerve.
25. GOALS OF SURGERY
To improve function rather than restore normal
function
To improve thumb pinch
To correct finger clawing
To restore the normal pattern of finger flexion
To restore ring & little finger DIP joint flexion in high
ulnar nerve palsy.
To restore sensation to ring & little finger(possible but
not attempted)
To restore the concavity of the transverse metacarpal
arch & correct little finger abduction deformity.
26. PRINCIPLES OF NERVE REPAIR
Contused or attenuated nerve usually left intact.
Resection of unhealthy fascicles in nerve ends should
not be compromised to preserve length.
Tension free repair with good alignment of fascicles
Mobilisation of 1-2 cm to allow repair
Trimming of fascicles & loose epineural sutures to
prevent buckle
Nerve grafting is preferable to avoid tension
Ends are tagged by prolene 6-0 if staged repair is
planned.
27. INTERNAL TOPOGRAPHY
At mid forearm Three distinct fascicular group(dorsal sensory, volar
sensory,motor group).
Motor group positioned between ulnar dorsal sensory
& radial volar sensory group.
Dorsal sensory group separates from the main nerve
approx 8 cm proximal to wrist.
Motor group remains ulnar to the volar sensory group
until the guyon’s canal, then it passes dorsally &
radially to become the deep motor branch to the
intrinsic muscles.
29. LATE DEFORMITIES & DEFICIENCIES
Claw finger:
static techniques Only if passive flexion of MP joint results in extension
of PIP.
•
Zancolli’s palmar capsulodesis of MCP joint
•
Omer’s modification of Zancolli technique
•
TenodesisParkes(PL & Plantaris)
Fowler (tendon graft sutured to ER)
Riordan( ECRL & ECU )
30. DYNAMIC TENDON TRANSFERS
Stiles & Bunnell – Both slips of all the superficialis
tendon transfered to both radial & ulnar lateral bands
of extensor mechanism.
Modified Stiles & Bunnell- FDS of middle finger
Fowler’s technique – EIP & EDM transfer
Modified Fowler – EIP transfer (2 slips)
Dorsal route transfer of ECRL/ECRB
Flexor route transfer of ECRL (through the carpal
tunnel)
PL 4 tail transfer
31.
Ulnar deviation of little finger:
•
EDM transfer
Flexion-adduction of thumb :
•
•
Littler-Ring finger superficialis
Smith-ECRB as motor
Z-thumb:
•
Split FPL-EPL transfer tenodesis
MP & IP jt arthrodesis
•
33. Restoration
of transverse metacarpal arch
Bunnell’s tendon T operation
A detached FDS attached to middle of a free tendon
graft, one end of graft inserted to base of proximal
phalanx, other to little finger metacarpal neck.
Restoration of sensibility:
Lewis’ digital nerve transfer
Wasted intermetacarpal spaces:
Dermal graft placement
34. MANAGEMENT IN LEPROSY
MDT
• Surgery acute- decompression in severe pain
abscess drainage in neuritis
quiescent- reconstructions after stopping steroids.
•
35. Management in case of poliomyelitis
Surgery delayed till child is 5 years of age
Cubital tunnel syndrome:
Early- conservative for 3 months
Static elbow extension splint
Simple unroofing of cubital tunnel is not
recommended.
Submuscular anterior transposition(so that
elbow flexion relaxes rather stretches the
nerve)
& avoiding injury to the medial
antebrachial cutaneous nerve to
forearm.
36. Treatment of Guyon’s tunnel syndrome:
Decompression by incising along radial border of FCU
(avoiding injury to dorsal branch of ulnar nerve which
does not pass through this canal)
Dissecting from distal to proximal along ulnar artery
branches to ring & small fingers, progressively
unroofing & deroofing the guyon canal is more safer.
