Closed
· supraclavicular (roots and trunks)
· preganglionic (avulsion of roots)
· postganglionic (rupture of trunks)
· infraclavicular (cords and branches)
Open
Other
· obstetric
· Erb
· Klumpke
· postanaesthetic
· radiation
· tumour
· iatrogenic
· closed injuries usually from MBA
· open injuries usually from
· stabbing
· gunshot
· of patients with plexus injuries
· 80% have have severe injury to whole body
· 20% have rupture of subclavian artery or axillary vessels
· 90% have fractures or dislocations in vicinity of plexus
· Narakas’ rule of 7s
· 70% MVA
· 70% of those MBA
· 70% associated other injuries (diagnosis frequently delayed)
· 70% supraclavicular
· 70% C8,T1 involvement
· 70% root avulsions
· 70% persistent pain
Preganglionic supraclavicular
· root lesions
· severe pain
· tenderness and swelling in posterior triangle
· spinal cord injury
· esp. Brown-Sequard
· vascular injury
Upper roots (C5,6)
· features of upper trunk above PLUS deficits from branches from roots and trunk
· winging of scapula
· long thoracic n - serratus anterior
· paralysis of rhomboids
· dorsal scapular n
· loss of shoulder ER
· suprascapular n - infraspinatus
Lower roots (C8,T1)
· features of lower trunk PLUS Horner’s syndrome
Guide to loss of function
· C5 - supraspinatus and infraspinatus
· C6 - ECRL*, biceps, brachioradialis, pronator teres
· C7 - latissimus dorsi
Postganglionic supraclavicular
Upper trunk
· loss of shoulder abduction
· deltoid
· loss of elbow flexion
· biceps, brachialis, brachioradialis
· loss of forearm pronation
· pronator teres
· numb outer arm and forearm
Middle trunk
· loss of wrist and finger extensors
Lower trunk
· loss of wrist and finger flexion
· FCU, FDS, FDP
· loss of intrinsics
· numb ulnar forearm and hand
Infraclavicular
Lateral cord
· weakness of elbow flexion
· musculocutaneous - biceps
· weakness of pronation and radial wrist flexion
· lateral root of the medial nerve - FCR and pronator teres
· weakness of shoulder adduction with arm horizontal
· lateral pectoral nerve - clavicular head of pec. major
· numb anterolateral forearm
· lateral cutaneous n of forearm
Posterior cord
· weakness of shoulder internal rotation
·
upper and lower subscapular nn - subscapularis and teres major
· weakness of shoulder adduction
· thoracodorsal - latissimus dorsi
· weakness of shoulder abduction and internal rotation
· axillary - deltoid and teres minor
· loss of elbow, wrist and finger extension
· radial - triceps, carpal and digit extensors
· numb lateral arm and snuffbox
· axillary n and radial n
Medial cord
· combined medial and ulnar nerve deficit
Chest x-ray
· elevation of diaphragm
· fracture or dislocation of 1st rib
Cervical x-ray
· avulsion of C7 transverse processes
Shoulder x-ray
· fracture of clavicle or scapula
· dislocation of shoulder, AC jt or SC jt
· based on fact that Wallerian degeneration does not occur in preganglionic lesions
· axons intact where lesion between cell body and spinal cord
Histamine test
Triple response
1. red reaction
· due to capillary dilatation
· direct response of capillaries to pressure
2. wheal
· due to fluid extravasation from increased permeability
· produced by histamine release
3. flare
· due to arteriolar dilatation
· due to axon reflex in sensory nerve
· antidromic conduction leads to release of substance P near arterioles supplied by same sensory nerve
Histamine test
· intradermal injection of histamine causes triple response
· preganglionic lesion
· afferent axons remain intact
· normal triple response with flare seen
· postganglionic lesion
· sensory cell body and axon separated
· afferent axons degenerated
· redness and wheal but no flare response
· no longer routinely performed
Nerve conduction studies
· general
· muscle sampling of specific groups of interest
· denervation shows sharp waves and fibrillation potentials
· renervation shows polyphasic action potentials on volitional activity
· preganglionic lesion
· skin anaesthetic
· sensory action potentials persist
· cervical paravertebral muscles show denervation
· serratus anterior and rhomboids show denervation
· postganglionic lesion
· skin anaesthetic
· no sensory action potentials
CT-myelogram
· pseudomeningocoele
· from leakage of dye
· indicate root avulsion
· may have false negative early
· due to clotted blood
· should delay 6 weeks
MRI
· role still unclear
· not routine at present
Exploration
· definitive investigation
Early exploration
· within 2 weeks of injury
· becoming more popular in specialised hand units
· advantages
· easier as less scarring
· diagnostic and prognostic
· disadvantages
· if nerve intact but not functioning, could be neuropraxia or axonotmesis
Late exploration
· 6-12 weeks
· traditional treatment
· advantages
· neuropraxia has resolved - if nerve intact but not functioning, is axonotmesis
Initial
· give priority to
· vascular compromise
· other life-threatening injuries
· associated fractures
Open
· may be amenable to direct repair
· ends may be cleanly divided
Sharp injury
· exploration and repair when
· patients condition permits
· facilities and expertise available
· if repair not feasible
· marking for later repair
Gunshot injury
· deficit may be due to nerve ‘concussion’
· usually improves
· if no other major injury requiring surgery (pulmonary, vascular)
· observe for 3 months
· explore if no improvement or large residual deficit
Closed
· usually not amenable to repair
· extensive damage from traction
· initial exploration and repair not usually indicated
· occasionally performed in specialised centres
· treat initially with splinting and ROM
· perform electrical studies at 3 weeks
· consider exploration at 6 weeks if no improvement
· diagnostic tool
· better prognosis with
· infraclavicular cf. supraclavicular
· upper trunk cf. lower trunk
· restore
· elbow flexion (biceps)
· shoulder abduction and rotation (deltoid, supraspinatus, infraspinatus)
Indications for surgery
· patient fit
· C5,6 or upper trunk lesion
Contraindications to surgery
· patient unfit
· preganglionic C8 T1 lesion
· some function in all nerves or trunks
Nerve repair
Indications
· tidy open injuries
· uncommon
Neurolysis
· exterrnal rather than internal
· indicated where there is
· neuroma in continuity
· scarring encompassing nerve
· may improve pain
Nerve graft
Indications
· postganglionic lesions
Donor
· sural nerve
· as cable graft
· ulnar nerve
· where there is a hopeless injury of C8T1
· use vascularised ulnar nerve for graft
· freeze-dried muscle
· promising technique
Repair
· suture
· laborious
· fibrin glue
· quick and effective
Nerve transfer
Indications
· C5,6,7 root avulsion with intact C8,T1
Aims
· reconstruct simple shoulder, elbow and wrist activity
· not for complex hand activity
Donors
· intercostal nerves
· 2 or more used
· spinal accessory nerve
· no functional deficit as transected after 1st branch to trapezius
Transfers
· accessory to suprascapular
· intercostal to musculocutaneous
· Z-shaped incision
· longitudinal along posterior border of SCM
· transverse along inferior border of clavicle
· longitudinal in deltopectoral groove
· ligate
· external jugular v
· transverse cervical a
· suprascapular aa
· divide
· omohyoid
· protect
· accessory n
· may need to osteotomise clavicle
C5
Preganglionic
· shoulder
· accessory nerve to suprascapular
· intercostal nerves to axillary
Postganglionic
· nerve graft
C5 C6
Preganglionic
· shoulder
· accessory nerve to suprascapular
· intercostal nerves to axillary
· serratus
· reinnervate with nerve to levator scapulae
· elbow flexion
· ulnar nerve to biceps
· wrist extension
· muscle transfer
· median nerve sensation
· ICN to lateral head of median n
Postganglionic
· nerve graft
C8 T1
· still a problem
· mainly tendon transfers
· common in pre-ganglionic injuries
· remains severe in 50%
· anti-epileptic drugs are of some value
· TENs useful
· successful nerve regeneration eases pain
· last resort is ablative CNS surgery
Shoulder stability
Tendon transfers
· in form of trapezius to proximal humerus
· results not good
Arthrodesis
· indicated where
· total loss of shoulder control
· functioning serratus and trapezius to allow movement
· results inferior to those performed for isolated palsies
· widespread weakness with few donors
· extensive sensory loss
Elbow flexion
· bipolar latissimus dorsi transfer
· complete lat dorsi transfer on neurovascular pedicle
· attached proximally and distally to replace biceps
· triceps to biceps transfer
· Steindler flexorplasty
· transfer of common flexor origin to distal humerus
· Clark pectoralis major transfer
· transfer of sternocostal portion of pectoralis major
· free gracilis transfer
· innervated by intercostal nerves
Wrist stability
Arthrodesis
· indicated where
· wrist flexion and extension not possible
· stability will create functional hand
Amputation
· midhumeral
· occasionally performed
· indications
· flail limb
· back at work
· limb is a hazard
· should not be performed for pain relief
Open
· direct repair effective in upper and middle trunks
· poor prognosis after lower trunk injury
Closed
· infraclavicular lesions improve in 80% after surgery
· supraclavicular lesions improve in 20%
· birth injury of brachial plexus
· usually caused by traction
· 0.4 per 1000 live births
· increased risk with
· heavy baby
· shoulder dystocia
· forceps delivery
· breech
· C5,6 lesion
· weakness of
· deltoid
· rotator cuff (abduction and external rotation)
· elbow flexion
· forearm supination
· wrist and hand extension
· sensation intact
· waiter’s tip deformity
· shoulder adducted (by side) and internally rotated
· elbow extended
· forearm pronated
· wrist and elbow flexed
· best prognosis
· rare
· C8,T1 lesion
· weakness of
· wrist and finger flexors
· intrinsics
· loss of sensation in forearm and hand
· Horner’s syndrome if preganglionic
· poor prognosis
· C5-T1
· flaccid arm and loss of sensation
· Horner’s syndrome if preganglionic
· worst prognosis
· 90% eventually recover
· most reliable indicator of recovery is return of biceps activity by 3rd month
· most recover within few days
· if no recovery by 3 weeks, degenerate injury
· if no recovery by 3 months, permanent defect
· if persisting complete lesion at 3 months, poor prospect for return of function
· maintain full ROM by passive ranging
· no splinting
· perform EMG at 10 weeks if no recovery
· exploration indicated if
· no clinical evidence of recovery of biceps at 3 months
· no evidence of strong reinnervation on EMG
· performed in specialised unit
· intraoperative neurophysiological studies required
· may perform
· grafting
· neurotisation
Early
· performed at about age 4
· in the form of
· muscle/tendon transfers
· release of contractures
· similar principles to polio surgery
Late
· in the form of osteotomies
· humerus
· forearm