Ulnar Nerve Palsy
Clinical Picture
Motor Loss
1. Loss of MCPJ flexion
 Duchenne’s sign – clawing
 Caused by long extensors working to extend the unopposed MCPJ and
thus long flexors gain mechanical advantage at the IPJ
 little finger more often has more severe claw deformity, as opposed to ring
finger because of:
1. inherent increased laxity in little finger MP joint volar plate
2. 20- 50% of pts have median nerve cross innervation to lumbricals to
ring finger, thus preventing claw deformity of the ring finger;
 Clawing gets worse with high lesions as FDP recovers (good prognostic
sign)
 With recovery, clawing may get better in the absence of clinical detectable
intrinsic function
 Only occurs if
1. extrinsic tendons functional
2. MCPJ hyperextensible
 Does not occur with all ulnar nerve lesions
1. lumbricals median innervated (Martin Gruber)
2. MCPJ not hyperextensible
3. either long flexors or long extensors not working
 Bouvier’s test
 MCPJ hyperextension blocked, EDC can extend P2 and P3 (Bouvier
positive)
 Bouvier negative occurs if
1. central slip attenuated
2. PIPJ flexion contracture
 Andre-Thomas sign – palmar flexion of wrist in order to extend fingers
2. Loss of integration of MP and IPJ flexion
 Due to paralysis of RF and LF lumbricals
 Normal finger flexion is initiated at MPJ and then all 3 fingers flex
simultaneously
 In intrinsic paralysis, MPJ does not flex until IPJ flexion completed
 Fingers curl and roll into palm, pushing objects away instead of graspingprevents a wide span grasp
st
3. 1 MPJ Instability
 Due to paralysis of adductor pollicis
 Normally acts to adduct metacarpal, flex MCPJ and extend IPJ
 unopposed action of the thumb extensors leads to MCP hyperextension
deformity where as unopposed activity of FPL lead to IP joint hyperflexion
deformity;
 Jeanne’s sign – thumb MPJ hyperextension with key pinch
4. Flattened palmar arch
 Masse’s sign – loss of hypothenar elevation (paralysis of opponens digiti
quinti)
5. Loss of ulnar 2 FDP
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Pollock’s sign - inability to flex distal phalanges of ring/little finger
Kapadji’s sign – loss of ulnar hook. Place examiner’s index finger on patient’s
palm and ask patient to hook DIPJ around finger. Patient will have unable to
resist force extension of the hook
6. FCU paralysis
 Slightly weakened wrist flexion
7. Impairment of precision grip
 Related to loss of intrinsics
 Inability to cross index/middle fingers on flat surface – tests 1st volar and 2nd
dorsal interossei
 Pitres-Testut sign – inability to abduct middle finger in radial or ulnar
direction; also inability to bring all extended fingers into a cone
 Wartenberg’s sign – EDM unopposed causing LF adduction (main differential
– rupture of deep transverse metacarpal ligament)
8. Loss of distal stability and rotation for tip pinch
 Froments sign - flexion of IPJ with attempted key pinch
 Bunnell’s O sign
 Impairment in power grip is greater that the loss of power for precise grip
Sensory Loss
9. Loss of ulnar one and a half fingers
10. Loss of ulnar dorsum of hand – high nerve lesion

Main complaint of patients with ulnar nerve paralysis is the loss of effective pinch
and coordination between the thumb and the index finger.
Variations in Ulnar nerve supply
1. predominantly C8 and T1, in 5-10% FCU is innervated by C7 rather than C8/T1
2. Martin-Gruber anastamoses
a. High communication from median to ulnar
b. Usually motor, sensory has been described
c. Incidence 10-30% (most quote 15-17%)
d. May arise from
i. anastomosis arose from the branch of the median nerve to the
superficial forearm flexor muscles (47%); intimately related to the
anterior ulnar recurrent artery, and connected with the ulnar nerve
about 2 cm below the medial epicondyle (range from 1.6 –2.5 cm)
very close to the level at which the ulnar nerve gave off its branch
to flexor digitorum profundus
ii. anastomosis arose between the origin of the branch to the
superficial forearm flexors and the origin of the anterior
interosseous nerve in the main trunk (11%)
iii. anastomotic branch arose from the anterior interosseous nerve
(32%) - passes medially to join the ulnar nerve in either its upper or
middle one-third.
e. Riche-Cannieu
f. Prevalence 1-4%
rd
3. 3 lumbrical has dual innervation in 50% of hands
4. 1st dorsal interossei is innervated completely or partially by median nerve in 10%,
radial nerve in 1%
5. Dorsal ulnar border of hand may be supplied by radial nerve
Timing of tendon transfers
Early
 Indications
1. where recovery is unlikely – segmental proximal nerve injury
2. internal splints
o external splints usually awkward and interfere with rehabilitation
of sensibility
o to maintain dynamic positions for functional coordination and
sensibility reeducation
o to prevent deformity
o decrease cortical exclusion
NOTE: FDS LF/RF cannot be used for high ulnar nerve lesions
INTERNAL SPLINTING
Superficialis Y Technique (Omer)
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Addresses:
1. intergration of finger flexion
2. key pinch
3. flattened metacarpal arch
FDS RF or MF
Less suitable for high palsies
3 slips fashioned
o Radial slip under FDPs and attached to adductor pollicis
o 2 ulnar slips to RF and LF looping under and over A2
 If Bouvier negative, then these slips are passed radial and dorsal to
attach to insertion of central slip
Combine with Thumb arthrodesis if positive Jeanne’s sign following FDS transfer
o Improves distal stability for tip pinch
o The joint is approached through a dorsal EPL splitting approach and a
chevron shaped arthrodesis is performed
o A desired flexion of 10-15 degrees is required and k wire fixation for 6
weeks
o This combination will improve 4 of 6 lost motor function, does not add
strength to power grip and reduces grip strength if FDS RF used
CONVENTIONAL TECHNIQUES
Proximal Phalanx Flexion
 Aim to prevent MPJ hyperextension to allow proximal phalanx flexion
 One of the debates is whether to address just the RF and LF or whether to do all
the fingers.
 Brand states that the I and M will ultimately also develop clawing as the palmar
soft tissues stretch and he therefore advocates doing all 4. (may only be apparent
during power pinch)
 The Zancolli operation also deals with all 4.
 Must be determined if claw is actively correctable (by Bouvier test)
Static Block Techniques
Only 1 function – correction of deformity. Indicated only when transfers are not
available because of extensive paralysis
1. Bone block on dorsum of metacarpal head (Mikail)
2. Arthrodesis of MCPJ – limits flexion of fingers into palm
3. Capsulodesis (Zancolli, 1957 - poor procedure) volar approach to MPJ. Volar
plate proximal base cut and drawn proximally and sutured into the metacarpal
neck in 20 Degree flexion. This results in a minimal flexion contracture, Long
term results show recurrence of the deformity.
4. Flexor pulley advancement (Bunnell) - Each side of the proximal pulley is split
1.5-2.5 cm to the middle of the proximal phalanx. The flexor tendons will then
Bowstring which increases the movement across the joint and power of
flexion.(not effective if damage to extrinsic extensors exist and subject to ulnar
drift if carried distal to A2)
5. Static tenodesis
o Parkes– free tendon graft between radial lateral band of dorsal apparatus
and deep transverse metacarpal ligament through the lumbrical canal. Most
predictable of all the static procedures
o Roirdan - Useful for patients who don’t need the power (sedentary office
workers). Uses dorsal approach to ECU and ECRL the two tendons are
split longitudinally, and one half of each tendon is divided proximally
(distally based). They are further split long into two halves. They are then
passed volar to the DTML and sutured to the radial lateral bands. Sutures
with the wrist in 30 ext and MP joint in 80 flexion
Dynamic Techniques
1. Integration of finger flexion
a. Fowler dynamic tenodesis
i. Tendon grafts from dorsal retinaculum, pass volar to DTML,
through lumbrical canal and into radial lateral band
ii. When wrist flexes, graft tightens and MCPJ flexes with PIPJ
extension
iii. Sutured with the wrist in 30 deg ext and MP joint in 80 deg flexion
and IP joints 0 degrees
b. Superficialis transfer
i. FDS 4 tail procedure (Modified Stilles-Bunnell transfer)
 FDS MF and/or RF (4 tail split)
 Volar to DTML into lumbrical canal
 Inserted into transverse fibers of radial lateral band or looped
around A2 (lower risk of Swan neck deformity)
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Avoid in high palsy unless using FDS MF
Does not add power to finger flexion
ii. Zancolli lasso procedure
 transverse incisions were made along the distal palmar crease on
the volar surface of the MP joints.
 FDS MF tendon divided at the level of the proximal phalanx and
divided into 4 slips
 FDS slips looped around A1 pulley
 Omer modifies it to loop around A2
 Transfers should be carried out in all fingers as weakness is not
limited to clawing fingers alone
 Does not result in increase in grip strength
 Another variation involves using EI passed through the
interosseous membrane to the FDS tendon
2. Integration of finger flexion with Increasing grip strength
 Need to add extra muscle-tendon unit
 Best candidates – wrist extensor or brachioradialis
 Motors
1. ERCL
2. Brachioradialis
3. ERCB
4. EI
5. FCR (in those with wrist flexion deformity)
 Insertion
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1. lateral bands of dorsal apparatus
2. bone of proximal phalanx
3. A2 pulley
Burkhalter – ECRL+tendon graft to proximal phalanx bone
Brand’s intrinsic transfer
o Short transverse incision at distal end of radius
o ECRL+ graft thru extensor retinaculum/ intermetacarpal
space/volar to DTML/lumbrical canal to radial lateral band
LF/RF/MF and ulnar lateral band IF (facilitates supination with
pinch)
o Variation passes ECRL under brachioradialis through the carpal
tunnel (risk compression of nerve and flexion contracture wrist) –
advantage of this is that grip strength is improved with wrist
extension but most patients are used to flexing their wrists to grip
(Andre-Thomas sign)
Riordan
1. EI divided into 2 slips volar to DTML to radial lateral band LF/RF
2. FCR+ graft passed dorsally and volar to DTML and into radial lateral
bands (if palmar flexion deformity)
Caveats
Note with using tendon grafts
 Plantaris absent in 8%-20%
a. When absent, usually absent bilaterally
b. U/S is good test to look for plantaris (95% sensitivity)
 Palmaris absent in 15%
a. When absent, absent bilaterally in 60%
 40% loss in grip strength after low ulnar nerve palsy, 30% for pure median nerve,
and 55% for combined
 In high ulnar lesions, flexion of middle and distal phalanx is not provided by these
procedures
 If EDC attenuated/ineffective or DIPJ/PIPJ stiff, then consider arthrodesis
Thumb-Index key and tip pinch
 Adduction is extremely important -creates the "key pinch" against the index finger
which is paramount important for daily activities such as opening a door with key,
buttoning clothes, etc.
 Key pinch – thumb is in adduction and flexion
o Adductor pollicis (mainly) and 1st DI are responsible for key pinch (the
thumb is in adduction and flexion) EPL and FPL may contribute to a
degree.
 Tip pinch – need index in radial deviation
 If the thumb can pinch strongly without hyperflexion of the IPJ (Froments sign) or
hyperextension of the MCPJ (Jeanne’s sign), surgery is not indicated.
 75-80% loss of key pinch in patients with ulnar nerve palsy
 Most tendon transfers for thumb adduction lead to 25-50% of normal strength
1. Thumb Adduction
a. Smith BR or ECRB (+ tendon graft)
i. passed between IF and MF metacarpus to adductor insertion.
ii. Passed volar to adductor pollicis but deep to long flexor tendons.
iii. The graft is adjusted so the thumb lies just palmer to the IF when
the wrist is in 0 degrees extension
b. Omer
i. ECRB + free tendon graft tunnels between MF/RF metacarpus
ii. passing volar to the adductor muscle but deep to the flexor tendons
and N/V bundle and attached to the abductor tubercle.
iii. This improves pronation for pinch. With the wrist in palmar flexion
the thumb falls into abduction. With the wrist in dorsiflexion the
thumb adducted against the palm. Preferable to a volar transfer.
c. Fisher uses ECRL + graft
d. Littler MF or RF FDS (One limb of FDS used) can be routed through a
split in the palmar fascia (vertical septum of the 3rd metacarpus acts as a
pulley) and attached to the Abductor tubercle. Post op immobilization for
three weeks. Returns of power pinch to 70 % normal (Brand likes this
transfer)
e. EIP between IF and MF passed volar between 3rd and 4th MC’s and
sutured to the adductor pollicis insertion. Brand recommends insertion into
abductor pollicus brevis tendon.
f. Bunnell tendon loop – EDC IF + tendon graft passing subcutaneously
around ulnar border of hand, across the palm deep to flexor muscles and
into bone of proximal phalanx
g. Robinson
i. Slip EDM to adductor tubercle
ii. EIP looped around 1st dorsal interosseous tendon and reattached to
base of proximal phalanx. Loop allows abduction of IF
h. Can fuse IP (preferred) or MCPJ to overcome positive Froment/Jeannes
i. An option when the other joints of the thumb are working well.
ii. IPJ fusion transforms the flexor pollicus longus and the extensor
pollicus longus into adductors and increases the adductor strength
by at least 30%.
2. Index Abduction
 Attached to 1st DI
 Improves pinch strength 10-15%
 Arthrodesis will stabilise key pinch and improve tip pinch
 Options for motors: Any radially innervated muscle at the radial border of
the wrist
a. EPB – not considered a very strong muscle May be used in combo
with EI with EI to ADD Poll and EPB to DI (Bruner). Best used when
1st MCPJ fused.
b. APL slip transferred with a tendon graft into tendon of 1st DI The APL
is exposed distal to its compartment and only the slip that attaches to
the first MC is important Any additional slips may be transferred . It
does not significantly increase the force of pinch but it stabilizes the
index finger. (Neivaiser)
c. EIP –Detached from IF dorsal apparatus and withdrawn at the wrist
through a short incision and then transferred around the radial border
of the 2nd MC and inserted into the 1st DI tendon volar to the axis of
the MPJ. Must be sutured under considerable tension (2-3kg) (Bunnel)
Omer modification is by splitting this tendon and using one slip to the
DI and one to the Add Pol
d. EDM
e. Brachioradialis
f. ECRL (and graft)
g. FDS – FDS ring brought out at the wrist an the transferred subcut
around the radial aspect of the forearm and inserted into prox phalanx
or into the DI (Riordan)
h. Palmaris longus taken with palmar aponeurosis
3. Arthrodesis of thumb
 IPJ fusion at 20-30 of flexion
o Some patients object to loss of movement here
 MPJ fusion 15 flexion, 5 adduction and 15 pronation
o when Jeanne sign positive
o preferred arthrodesis
Metacarpal arch restoration
 Flattening (instability) of the transverse metacarpal arch may contribute to
recurrent clawing following lumbrical replacement procedures
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Bunnels tendon T operation
o gives adduction to the thumb and the little finger while cupping the hand
to restore the metacarpal arch.
o tendon graft spans the hand dorsal to the flexor tendons from the base of
the thumb’s proximal phalanx to the neck of the LF metacarpus.
o A FDS is detached from the insertion and looped around the centre of the
free tendon graft to form a T . On contraction of the FDS the T is
converted to a Y and the MC arch is restored
Littler does not use tendon graft but splits FDS one slip attached to the ADD
tubercle and the other to proximal phalanx of the LF
(Ranney) EDM divided at the MCPJ and transferred volarly between APL and
FCR and then tunnelled thru the palm to be sutured to the periosteum of the neck
of the 5th metacarpus
Little Finger Abduction
 EDM abducts little finger through its indirect insertion into the abductor tubercle
on the proximal phalanx.
 Ulnar half of EDM is passed volar to the DTML and attached to the radial
collateral ligament of the LF MCPJ
o If clawing is present, then pass volar to DTML and loop around A2 pulley
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Entire EDM passed under and over ECRL and inserted into the dorsal apparatus
of little finger or into proximal phalanx
The EDC tendinous intersection between RF and LF in continuity with the ulnar
half of the EDC RF harvested passed volar to the DTML and sutured to the radial
collateral or radial aspect of dorsal hood.
o Beware slackening the extensor mechanism of the finger when the
transferred slip is too short
Loss of ulnar half of FDP
 To improve grip strength, tenodesis of LF/RF FDP to MF FDP (avoid IF FDP) at
the wrist
Loss of FCU
 Consider transferring FCR to FCU is a patient with high ulnar nerve palsy who
needs to perform activities requiring strong wrist flexion (ulnar deviation
important here)
Loss of sensation
 Options
o Free nerve grafting
o Vascularised nerve grafts
o Free neurovascular cutaneous island flaps
o Digital nerve translocations
Summary (my approach) – low ulnar nerve palsy
1. improve clawing and grip strength
a. Brand transfer (ERCL - dorsal and tendon grafts)
b. Zancolli lasso procedure
2. EDM ulnar slip passed volar to the DTML and attached to the radial collateral
ligament of the LF MCPJ