Peripheral nerve injury and entrapment neuropathy-1.pptx

TRAUMATIC & ENTRAPMENT
NEUROPATHIES
DR BIPUL BORTHAKUR
PROFFESOR AND HEAD
DEPARTMENT OF ORTHOPAEDICS ASSAM MEDICAL COLLEGE
DIBRUGARH , ASSAM

ANATOMY:(STRUCTURE OF A PERIPHERAL
NERVE)
• A peripheral nerve consists of masses of axis cylinders(axons), each with a
neurilemmal tube.
• Enclosed in a collagen connective tissue known as endoneurium.
• A bundle of nerve fibres are further bound together by fibrous tissue to form a
fasciculus.The binding fibrous tissue is known as perineurium.
• A number of fasciculi are bound together by a fibrous tissue sheath known as
epineurium.

ANATOMICAL FEATURES RELEVANT TO NERVE
INJURIES:
1. Relation to surface: Superficially placed nerves more prone to injury.
2. Relation to bone: Nerves in close proximity to bone, more prone to injury.
3. Relation to fibrous septae: Some nerves pierce fibrous septae along their course .
They may get entrapped in these septae .
4. Relation to major vessels.
5. Course in a confined space. e.g. Median nerve compression in carpal tunnel
syndrome.
6. Fixation at points during the course. e.g. Common peroneal nerve is relatively
fixed over the neck of fibula.

PATHOLOGY
NERVE DEGENERATION
• Part of neuron, distal to point of injury undergoes secondary or Wallerian
degeneration.
• Proximal part undergoes primary or retrograde degeneration.

NERVE REGENERATION
• As regeneration begins, the axonal stump from the proximal segment begins to grow
distally.
• If the endoneural tube with its contained Schwann cells is intact, the axonal sprout
may readily pass along its primary course and reinnervate the end-organ.
• Rate of recovery of axon is 1mm per day.
• Muscle nearest to the site of injury recovers first.
• Nerve innervates muscle from proximal to distal called as motor march.

MECHANISM OF INJURY:
1. Fractures and dislocations ( most common cause)
2. Direct injury- cuts, lacerations
3. Infections- Leprosy
4. Mechanical injury- compression, traction,friction
5. Cooling and freezing- Frost bite
6. Thermal injury
7. Electrical injury
8. Ischaemic injury- Volkmann’s ischaemia
9. Radiation
10. Toxic agents- e.g.- Tetracycline leading to radial nerve palsy

ENTRAPMENT NEUROPATHIES
• Also known as nerve compression syndrome
• Compression of peripheral nerves
• When the nerve traverse through fibro- osseous tunnel, risk
of entrapment and compression occurs

ENTRAPMENT NEUROPATHIES
MEDIAN (at wrist)
CARPAL TUNNEL SYNDROME
Pain, paraesthesia on palmar aspect of
hands and fingers, pain may extend to arms
and shoulder
ULNAR( at elbow) Paraesthesia on medial border of hand, wasting
and weakness of hand muscles
RADIAL Weakness of extension of wrist and fingers
(often precipitated by sleeping in abnormal
posture)
PERONEAL Foot drop , trauma to head of fibula
LATERAL CUTANEOUS NERVE OF THIGH
(meralgia paraesthetica)
Tingling on lateral border of thigh

RADIAL NERVE PALSY
• It is continuation of posterior cord of brachial plexus
• Commonest peripheral nerve to be injured.
• Etiopathogenesis-
 High radial nerve injury-
 nervy injury at radial groove
 All muscles except triceps and anconeus are affected.
 If injury occurs in axilla (Saturday night palsy) all muscles
affected.
 Low radial nerve injury-
 Occurs due to injury at distal arm and around elbow.
 Eg- Holstein Lewis fracture
 Brachioradialis ,ECRL ,ECRB spared.

Sensory distribution of different nerves

RADIAL TUNNEL SYNDROME
• When radial nerve gets compressed in the elbow
• Entire arcade from lateral epicondyle to the arcade of frohse is affected.
• May involve both the sensory and motor components of radial nerve
 CAUSE: fibrous bands anterior to radio capitellar joint, synovitis of radiocapitellar
joint, proximal and distal edge of supinator muscle, radial artery branches at radial
neck
 Tests : rule of 9 test

CHEIRALGIA PARAESTHETICA:
• Compression neuropathy at the level of wrist joint or proximal to the level of wrist joint
• Also called “WARTENBERG SYNDROME”
• Compression of superficial branch of radial nerve
• CLINICAL FEATURES:
Paraesthesia over dorsum of wrist
Loss of sensation over lateral 2& ½ fingers

MECHANISM OF RADIAL NERVE INJURY

MOTOR & SENSORY ASSESSMENT OF RADIAL NERVE

TREATMENT
• Conservative:
• Long cock up /Dynamic cock up splint+Physiotherapy
No response—
Tendon transfer/Arthrodesis

MEDIAN NERVE INJURY
• Site of injury
 Around elbow: supracondylar fracture
 Hand of benedicton present
 All muscles supplied by median nerve affected
 No appreciable clawing
 Ulnar paradox
 Oschner pointing index sign positive
 At wrist:
 Caused by carpal tunnel syndrome
 Ape thumb deformity, nail sign positive
 Wasting of thenar eminence

1. High median nerve palsy
• Injury proximal to elbow
• Causes paralysis of all the muscles supplied by median nerve in the forearm and hand.
• Sensory deficit in the skin of the hand.
2. Low median nerve palsy
• Injury in the distal third of forearm.
• Forearm muscles are spared but muscles of hand are paralysed.
• Anaesthesia over median nerve distribution in the hand.

ENTRAPMENT-CARPAL TUNNEL SYNDROME
Thenar atrophy

CAUSES OF CARPAL TUNNEL SYNDROME
• Myxedema
• Pregnancy
• Idiopathic
• Amyloidosis
• Acromegaly
• Neoplasm
• Trauma at wrist
• Diabetes
• Rheumatoid arthritis

ASSESSMENT OF MEDIAN NERVE INJURY
Tinel sign
Pen test Phanlens test

MANAGEMENT
• Close injury: analgesic+ physiotherapy + orthosis
3 EMG study in 4 weeks gap
fail to improve
surgery
• Open injury : primary repair( <12 hours) or delayed primary reapir(<2.5 weeks) or
secondary repair (3 weeks)
• Carpal tunnel syndrome : carpal tunnel release

1. High ulnar nerve palsy-
• Injury proximal to elbow.
• Causes paralysis of all the muscles supplied by the ulnar nerve in the forearm and hand.
• Sensory deficit in the skin of the hand.
2. Low ulnar nerve palsy
• Injury in distal-third of forearm
• Sparing of forearm muscles but muscles of the hand will be paralysed.
• Sensory deficit same as in high ulnar nerve palsy.

MOTOR AND SENSORY LOSS
Ulnar claw hand Sensory loss in hand

TREATMENT
• nonoperative : nsaids + physiotherapy+ activity modification
wait for 3 months
do EMG,NCV study
surgery
• Cubital tunnel release
• Medial epicondylectomy
• Anterior transposition

SCIATIC NERVE
• Sciatic nerve consists of 2 anatomically distinct components- tibial and common
peroneal nerves.
• The common peroneal nerve supplies the extensors and the evertors of foot.
Paralysis results in foot drop. Patient walks with a “high-step gait”.
• The tibial nerve supplies the plantar flexors of the foot.We can test for weakness of
these muscles by asking the patient to plantar flex the ankle and toes.

FOOT DROP
• Causes-
Medical cause- leprosy , post polio residual paralysis
Iatrogenic- while giving tibial skeleton traction
Tight plastering compressing common peroneal nerve
Fractutre - fibular neck fracture, lateral tibial condyle fracture
Tumor - exostosis/lateral meniscus cysts
Above knee- post. Dislocation of hip, acetabulum fracture

MOTOR & SENSORY DISTRIBUTION OF COMMON
PERONEAL NERVE
Foot drop

CLINICAL FEATURES
• Low lesion –
Deep peroneal nerve : no ankle dorsiflexion , no foot inversion
Sup. Peroneal nerve: no eversion but dorsiflexion/inversion of foot preserved
• High lesion-
Sciatic nerve injury
Hamstrings also paralyzed

FEMORAL NERVE:
• Causes of injury:
Gunshot wound, applying pressure or traction during an operation,
 Clinical features: paralysis of quadriceps, patient is unable to extend knee actively,
numbness of anterior thigh, medial aspect of leg
 Knee reflex is depressed

LONG THORACIC NERVE
• Arises from the ventral rami of C5,C6,C7.
• It supplies the serratus anterior muscle
• The medial border of the scapula on the affected side will become prominent ( winging
of scapula

AXILLARY NERVE
• Root value (C5, C6)
• Supplies deltoid, teres minor muscle
• Direct continuation from the posterior cord of brachial plexus
• In the axilla, the axillary nerve is located posterior to the axillary artery and anterior
to the subscapularis muscle
• It exits the axilla at the inferior border of subscapularis via the quadrangular space,
often accompanied by the posterior circumflex humeral artery and vein

• The axillary nerve then passes medially to the surgical neck of the humerus, where
it divides into three terminal branches:
1. Posterior terminal branch – provides motor innervation to the posterior aspect of
the deltoid muscle and teres minor.
2. Anterior terminal branch – winds around the surgical neck of the humerus and
provides motor innervation to the anterior aspect of the deltoid muscle.
3. Articular branch – supplies the glenohumeral joint

TESTING THE AXILLARY NERVE
• Stabilise the scapula with one hand while the other hand is kept on the deltoid to
feel for its contraction.
• Ask the patient to abduct his shoulder.
• Inability to abduct the shoulder and the absence of the deltoid becoming taut
indicates deltoid paralysis.

TREATMENT OF NERVE INJURY
• CONSERVATIVE MANAGEMENT:
• Splintage of the paralysed limb
• Preserve mobility of the joint
• Care of skin and nails
• Physiotherapy
• Relief of pain: analgesics

OPERATIVE MANAGEMENT:
• NEUROLYSIS
• NERVE REPAIR
• NERVE GRAFTING
• NERVE TRANSFER

NEUROLYSIS:
• Application of physical or chemical agent to cause temporary degeneration of a
nerve
• Operation where nerve is freed from enveloping scar( perineural fibrosis); called
external neurolysis
• The nerve sheath may be dissected longitudinally to relieve the pressure from the
fibrous tissue within the nerve called internal neurolysis

NERVE REPAIR
• May be performed within a few days of injury or later
• TYPES:
• PRIMARY REPAIR: indicated in clean, sharp nerve injuries, done in first 6-8hrs of
injury
• DELAYED PRIMARY REPAIR: done in the first 7-18 days of injury, when the wound is
clean and there are no other major complicating injuries
• SECONDARY REPAIR: done in crushed, avulsed injuries, done at a delay of 3-6 weeks

TECHNIQUES OF NERVE REPAIR:
• NERVE SUTURE: indicated when the nerve ends can be brought close to each
other
• TECHNIQUES:
• epineural suture
• Epi-perineural suture
• Perineural suture
• Group fascicular repair

NERVE GRAFTING :
• Indicated when the gap is more than 10cm or end to end suture is likely to result in
tension at the suture line
• Most commonly used nerve is sural nerve
• Other source:
Medial antebrachial cutaneous nerve
Third webspace branch of median nerve
Palmar cutaneous and dorsal cutaneous branch of ulnar nerve

SIGNS OF REGENERATION OF NERVE:
• TINEL’S SIGN: on gently tapping over the nerve , from distal to proximal, a pin and
needle sensation is felt in the area of the skin supplied by the nerve. A distal
progression of the level at which it occurs, suggests regeneration ( 1mm/day)
• MOTOR EXAMINATION: the muscle supplied nearest to the site of injury is the first
to recover.The muscles in the more distal area begin to contract as they are
reinnervated one after another . (motor march: absent in neuropraxia)
• ELECTRODIAGNOSTIC TEST: helps in predicting nerve recovery even before it is
apparent clinically.
ELECTROMYOGRAPHY
NERVE CONDUCTION STUDY

PROGNOSTIC FACTORS FOR THE RESULT OF NERVE REPAIR:
FACTORS OUTSIDE OUR INFLUENCE:
 Nerve injured ( motor, sensory, mixed)
 Level of lesion ( proximal –distal)
 Accompanying lesion ( fractures,etc)
 Age of the patient
 FACTORS WHICH WE CAN INFLUENCE:
Delay between injury and surgery
Surgical technique

Peripheral nerve injury and entrapment neuropathy-1.pptx

Peripheral nerve injury and entrapment neuropathy-1.pptx

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