- See
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Cubitbal Tunnel Syndrome
-
Differential Dx: Ulnar Nerve Dysfunction:
-
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.
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General Orthopaedics: The Anatomy of the Distal Ulnar Tunnel.
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The Dorsal Branch of the Ulnar Nerve: An Anatomic Study.
- Palmar cutaneous branch of the ulnar nerve. WD. Engber and JG Gmeiner. J. Hand. Surg. Vol 5. 1980. p 26.
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Distribution pattern of the deep branch of the ulnar nerve in the hypothenar eminence.
- A Neural Loop of the Deep Motor Branch of the Ulnar Nerve: An Anatomic Study.
Rogers-MR. Bergfield-TG. Aulicino-PL. J Hand Surg. 1991. 16A. pp 269-271.
- A variation in the path of the deep motor branch of the ulnar nerve at the wrist. R. Lassa and MM Shrewsbury. JBJS. Vol 57-A. 1975. p 990.
- Trauma to Ulnar Nerve: (see:
nerve repair)
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combined lesions of the median and ulnar nerves:
-
high ulnar nerve lesions
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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: ECRL to Adductor Pollicis and Abductor Pollicis Longus to First Dorsal Interosseus Tendon Transfers
