ULNAR NERVE BRIEF ANATOMY AND CF

1. ULNAR NERVE ANATOMY &
LESIONS
DR.KARNA VENKATESWARA REDDY

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.

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.

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.

9. WRIST TO (MEDIAL) HAND

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

11. DORSAL CUTANEOUS BRANCH

12. PALMAR CUTANEOUS BRANCH

13. ETIOLOGY OF ULNAR NERVE PALSY
 Injuries
 Primary neurologic diseases
 Leprosy
 Compression neuropathies

14. CHARACTERISTICS OF PALSY
 INJURIES-
proximal : 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 inter-
metacarpal 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.

23. MANAGEMENT
ACUTE INJURIES
Closed
Localize clinically
Follow-up with EMG & NCS
Recovery No recovery
Observe surgery

24. Open
Surgery
Nerve in continuity not in continuity
As closed injury sharp crush
repair approxi
mate
Graft

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.

28. ULNAR NERVE TOPOGRAPHY

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
• Tenodesis-
Parkes(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

32.  Index finger abduction:
• Bunnell-EI
• Bruner- EPB
• Neviaser- accessory APL elongated by tendon graft
 High ulnar palsy-
• tenorrhaphy
• FCR to FCU

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.