- See
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Cubitbal Tunnel Syndrome
-
Differential Dx: Ulnar Nerve Dysfunction:
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Martin Gruber Anastomosis
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Ulnar Nerve Blocks:
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Ulnar Nerve in Condylar Fractures:
- Anatomy:
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brachial plexus:
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C8 and
T1 nerve roots give rise to the
medial cord which in turn, forms the ulnar nerve;
- ulnar nerve passes distally, just medial to
axillary artery, pierces medial intermuscular septum halfway down the arm, passes back over
medial head of
triceps, around posterior aspect of medial epicondyle, & enters forearm between two heads of
FCU;
-
anatomy and sites of compression in the cubital tunnel:
- just below elbow, it sends branches to
FCU & ulnar half of
FDP;
- it passes down forearm under
FCU , & then into
Guyon's canal;
-
dorsal sensory branch:
- the nerve emerges from the medial border of the FCU about 5 cm proximal to the pisiform;
- supplies dorsoulnar aspect of the hand and the ulnar 1 1/2 fingers;
-
terminal branches in the hand:
-
guyon's canal:
- superficial cutaneous branch to ulnar portion of palm & volar surfaces of ulnar 1 1/2 fingers,
- deep motor branch passes adjacent to hook of hamate;
- deep branch, innervating hypothenar muscles & third & fourth
lumbricales,
adductor pollicis, all
interossei, & deep head of
FPB;
- references:
-
The lateral root of the ulnar nerve.
- General Orthopaedics:
The Anatomy of the Distal Ulnar Tunnel.
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The Dorsal Branch of the Ulnar Nerve: An Anatomic Study.
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Palmar cutaneous branch of the ulnar nerve.
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Distribution pattern of the deep branch of the ulnar nerve in the hypothenar eminence.
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A Neural Loop of the Deep Motor Branch of the Ulnar Nerve: An Anatomic Study.
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A variation in the path of the deep motor branch of the ulnar nerve at the wrist.
- Trauma to Ulnar Nerve: (see:
nerve repair)
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combined lesions of the median and ulnar nerves:
-
high ulnar nerve lesions
-
low ulnar nerve injury
- division of ulnar nerve at wrist results in paralysis of all small muscles of hand except first & second
lumbricales & most of thenar muscles;
- paralysis of
adductor pollicis produces Froment's sign;
- when grasping piece of paper between thumb and index finger,
FPL fires (IP joint flexion) since adductor does not work;
- if ulnar nerve is divided below mid-forearm, ulnar
claw hand is produced; (
low ulnar nerve lesions);
- w/ this lesion, 4th & 5th fingers are hyperextended at MP joints by long extensors but flexed at interphalangeal joints;
- this posture is sometimes called hand of benediction;
- if ulnar nerve lesion is above midforearm, clawing of ulnar two fingers does not occur, because extrinsic
muscles producing IP joint flexion are also denervated (see
high ulnar nerve lesion);
- in complete
claw hand, produced by low lesion of
median nerve & ulnar nerves, MP joints are
extended & interphalangeal joints flexed by still-functional extrinsics;
- references:
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Repair of median and ulnar nerves. Primary suture is best.
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Epiperineurium-fascial stitches along the stumps of a transected nerve. An additional method for closing the gap in the nerve trunk.
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Experience with the free vascularized ulnar nerve graft in repair of supraclavicular lesions of the brachial plexus.
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The results of secondary microsurgical repair of ulnar nerve injury.
- Cubital Tunnel Syndrome:
- w/ severe cases of cubital tunnnel syndrome, there will be decreased two point sensory distribution of ulnar nerve
as well as muscle weakness and/or muscle wasting of
intrinsic innervated by the ulnar nerve;
- clinical findings include positive Froment's test, wasting of first dorsal interosseous muscle, inability to
cross index and middle fingers, &
clawing of ring & small fingers;
- Entrapment of Ulnar Nerve at Wrist:
-
clinical findings:
- positive Tinel's sign on percussion over ulnar nerve at
guyon's canal;
- positive Phalen's test w/ paresthesias in ring & small fingers
- it will not show loss of sensation over dorsoulnar aspect of hand;
- increase in two point discrimination;
- changes with
nerve conduction studies and electromyograms;
- pts may also develop
claw hand
-
diff dx:
- ganglion (produces motor and sensory deficit)
- frx (frx of 5th CMC or
hook of hamate)
- anomalous muscles;
- anomalous muscle belly at level of the wrist, which includes, palmaris brevis profundus,
ADM,
FDM, and
FCU;
- thrombosis of
ulnar artery or
SPA;
- synovitis;
- treatment:
- w/ compression of ulnar &
median nerves at wrist, ulnar nerve symptoms may improve with carpal tunnel surgery alone
Clinical features of paralytic claw fingers.
Acute ulnar neuropathy with fractures at the wrist.
The extrinsic blood supply of the ulnar nerve at the elbow: an anatomic study.
Tardy ulnar nerve palsy caused by cubitus varus deformity.
Three tendon transfer methods in reconstruction of ulnar nerve palsy
Restoration of Pinch Grip in Ulnar Nerve Paralysis: Extensor Carpi Radialis Longus to Adductor Pollicis and Abductor Pollicis Longus to First Dorsal Interosseus Tendon Transfers
