Peripheral Nerve Injuries - Bowen University
Transcript of Peripheral Nerve Injuries - Bowen University
DR. ANIPOLE O.A
Lecturer 1/ Consultant Orthopaedic Surgeon
NERVE
INJURY
OUTLINE
Relevant Physio-anatomy
Incidence Of Peripheral N.
Injury
Aetiopathology
Clinical Evaluation
Electrophysiogical Assessment
Imaging Techniques
OUTLINE
Treatments
Complications
Newer Techniques
Relevant Physio-Anatomy
Nerve is composed of neural and connective tissue.
In both myelinated and non myelinated axons, each nerve fiber is surrounded by the endoneurium.
Groups of nerve fibers are surrounded by the perineurium to form fascicles.
Goups of fascicles are surrounded by the internal and external epineurium.
Knowledge of motor and sensory fascicular topography within the nerve is essential to ensure correct alignment of the motor and sensory fascicles.
NERVE TRUNK
PERINEURIUM
BLOOD VESSELS
EPINEURIUM
FASCICLE
NERVE FIBER
MYELIN SHEATH
AXON
ENDONEURIUM
A MOTOR NEURONE
Incidence Of Peripheral
Nerve Injury Limited reported data are available
to determine incidence.
In North America, data taken from
a trauma population in Canada
revealed that approximately 2-3%
of patients had a major nerve
injury.
Incidence Of Peripheral
Nerve Injury
• Ulnar nerve inj: common ass with
# medial humeral epicondyle and
callus around the elbow,
Median nerve inj: common in
elbow dislocation
Incidence Of Peripheral
Nerve Injury
Axillary nerve stretch inj. occur in
~ 5% of shoulder dislocation
Peroneal nerve injury common in
fibular neck # or dislocation of
knee
Aetiopathophysiology
Peripheral nerve injuries may occur due to;
Trauma ( blunt or penetrating wound):
- Stab : from a knife, by a bullet, ragged end of fracture bone.
Vascular Ischaemia as in Volkman’scontracture of the forearm
Compression:
-Acute compression by haemorrhage or oedema: Compartment syndrome
-Chronic compression injuries.
Traction: E.g birth trauma→ Erb’s
palsy
Chemical / Burn injuries; from
injection of drugs, or adjacency of
methylmethacrylate material to the
sciatic nerve during total hip
replacement.
Aetiopathophysiology
Injury → Demyelination or axonal
degeneration
→ disruption of the sensory and/or
motor function
Remyelination /axonal regeneration
→ Reinnervation of the sensory
receptors, motor end plates, or both.
Aetiopathophysiology
Classification
Seddon in 1943 classified nerve injury as neurapraxia, axonotmesis, and neurotmesis.
• Sunderland in 1951 expanded this classification system to 5 degrees of nerve injury.
Mackinnon introduced the sixth degree.
Seddon,1943.
1. Neuropraxia –Minor contusion or compression. Demyelination without axon disruption or degeneration. Conduction block .Transient loss of function
2. Axonotmesis –The axons are disrupted with distal Wallerian degeneration but the endoneurium is intact
3. Neurotmesis –Total division & disruption in continuity of axons, all supporting structures including epineurium.
Classification
CLINICAL EVALUATION
History Taken
Clinical Examination
Inspection
- Lesions of various nerve often
results in a xtic limb attitude.
CLINICAL EVALUATION
Muscle tone
Reduced or abolished
CLINICAL EVALUATION
Muscle Bulk
Progressively atrophy to
approximately 50% - 2 months
Muscle Power
MRC method of grading muscle
power – 0 – 5.
CLINICAL EVALUATION
Sensory Assessment- Dermatones
CLINICAL EVALUATION
Examination of the nerve
Local Tenderness -
- Indicates an in complete
lesion
Tinel sign
- Evidence of axon sprouts
- Sensation of pins & needles
Electrophysiogical
Assessment
(1) Nerve Conduction Studies
(2) Electromyography
Nerve Conduction Studies
Particularly useful in determining
the anatomical site of compression
of a nerve. .
In cases of brachial plexus injury,
can help to determine the
presence of an avulsion injury.
Electromyography
◦ Performed at least 4 weeks following
nerve injury.
◦ Evidence of denervation is indicated
by the presence of fibrillations in the
muscle.
◦ Reinnervation is noted by the
presence of motor unit potentials.
TREATMENT
Conservative
◦ Use of splint or sling for support
◦ Passive mobilization
◦ Maintaining muscle strength in the
unaffected muscles.
No definitive studies have been done to
support the use of electrical muscle
stimulation to prevent muscle
degeneration.
FORMS OF SURGICAL
TREATMENT NERVE REPAIR
NERVE GRAFT
NERVE TRANSFER
TENDON TRANSFER
Types of Nerve Repair
PRIMARY 6 – 8
HOURS
DELAYED PRIMARY 7 – 18 DAYS
SECONDARY >18 DAYS
METHODS OF I ̊ REPAIR
EPINEURIAL
PERINEURIAL {FASCICULAR}
Group Fascicular
Epineurial Repair
Fascicular (funicular) Repair
Nerve Grafting
Sural Nerve
Ant. br. of medial cut. n. of the
forearm
Lat. Cut. n. of the forearm
POST OPT MGT
CARE OF WOUND
SPLINTAGE
PHYSIOTHERAPY/HAND
THERAPIST
FOLLOW-UP CARE
COMPLICATIONS
Injury - Related
PAINFUL NEUROMA
PARALYSIS
JOINT STIFFNESS
MUSCLE WASTING
REFLEX SYMPATHETIC
DYSTROPHY
COMPLICATIONS
Operation - Related:
Infection,
Hematoma,
Seroma, and
injury to surrounding structures,
including vascular structures.
Further injury to the nerve.
THANKSFOR
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