Adult Traumatic brachial plexus Palsy : management

CLASSIFICATION OF LESIONS• David Chuang has classified brachial plexus lesions into four

levels – 1. Preganglionic root2. Postganglionic spinal nerve3. Preclavicular & Retroclavicular (trunks & divisions4. Infraclavicular (cord and terminal branches)

CLASSIFICATION

TERMS• Rupture :- A break in continuity of a spinal nerve with two

disrupted ends (proximal and distal).• Avulsion :- tearing of nerve rootlets from the surface of the

cord ( proximal avulsion ) or of branches from the muscle (distal avulsion).

PREGANGLIONIC ROOT INJURY

• Comprises majority of closed brachial plexus injury in adults.• Nerves may be ruptured at the pre- ganglionic root zone or

avulsed from the spinal cord.• There may be single or multiple root injuries• The dorsal root ganglion may be undisplaced, mildly displaced

or displaced into the neck.

PREGANGLIONIC ROOT INJURY

• Preganglionic nerve injury is commonly seen with different type or different level of injury to other spinal nerves.

• These may be root avulsion of C7-T1 with rupture of C5-C6 spinal nerves or the upper trunk.

• However double injury (different level of injury) in the same spinal nerve is a rare phenomenon

PREGANGLIONIC ROOT INJURY

• The C5 spinal nerve is of greater length and curves upwards into the intervertebral foramen.

• It has a tendency to suffer rupture rather than root avulsion if the traction force is not too intense.

• The C7 spinal nerve runs parallel to the limb axis and more readily suffers root avulsion

• There are 10 scenarios suggestive of Preganglionic nerve injury.

1) Motor paralysis extending to proximal shoulder girdle and neck muscles such as levator scapulae, rhomboid, serratus anterior and deep posterior paravertebral muscles.

2) Sensory disturbance extending above the glenohumeral joint ( C4-3 sensory zone)

3) Intolerable pain( root “shooting” pain)4) Horner syndrome 5) No or weak tinel’s sign in response to percussion in the neck6) Cervical spine fracture7) Elevation of hemidiaphragm

8) Pseudomeningocele on standard cervical myelography or computed tomographic myelography9) Recording of sensory nerve action potential in an anaesthetic limb (with absent motor nerve action potential) 10) Negative intraoperative somatosensory evoked potential.

POSTGANGLIONIC SPINAL NERVE INJURY

• It is defined as injury occurring distal to the dorsal root ganglion (or outside the intervertebral foramen) but between scalene muscles.

• Differentiating between preganglionic nerve injury and postganglionic nerve injury is important with respect to all surgical procedures and predicting prognosis.

• This differentiation can be made using the above mentioned features on clinical examination and interpretation of investigation results .

Preclavicular and Retroclavicular injury

• This means that the injury involves the trunks and their divisions distal to the scalene muscles but before the divisions join to form cords.

• In these injuries rupture with neuroma formation was the most common finding.

Infraclavicular Injury• This means lesions involving the cords and their terminal

branches.• In a few patients these injuries extended to the supraclavicular

area usually in traction avulsion amputation in the upper arm associated with brachial plexus injury.

• Such injuries are commonly associated with ruptured lateral cord and C7 – T1 root avulsion.

• Broadly the injuries of the brachial plexus can be classified into • Supraclavicular which includes first three categories and • Infraclavicular• Broad distinctions of the two categories are as follows :-

Supraclavicular Infraclavicular

Location Preganglionic root ,postganglionic nerve or preclavicular and retroclavicular injuries

Cord and terminal branches

Inspection Drop Shoulder , Winged scapula, flail arm, Neck shifts to unaffected side

Flail arm

Associated #s (common)

Cervical spine vertebrae, first rib or clavicle

Scapula(glenoid ) or humerus.

Associated vascular injury

Subclavian Artery (low incidence)

Subclavian or axillary artery high incidence about 30%

Supraclavicular Infraclavicular

Type of Nerve Injury Root avulsion > Rupture with Neuroma

Rupture > Avulsion

Tinel’s sign Variable Dominant Below Coracoid Process.

Surgical procedures More nerve transfers More nerve grafts and vessel repair

Surgical Results Unpredictable ; more aberrant reinnervation

Better results , less aberrant reinnervation

Classification of nerve injuries• Seddons :- • Neuropraxia- Local conduction block with segmental

demyelination, no axonal abnormalities

• Axonotmesis – Axonal injury but endoneurium and perineurium are intact.

• Neurotmesis Complete transection of the nerve

• Sunderland :-• First degree = Neuropraxia• Second degree = Axonotmesis• Third Degree = Axonal damage with varying degree of

scarring of the endoneurial tube, the perineurium remains intact

• Fourth degree = Severe damage to nerve fibers but the nerve is physically intact , No functional recovery

• Fifth degree = Neurotmesis• Sixth degree = Neuroma in continuity ,added later

• Seddon’s axonotmesis or Sunderlands’s second degree injury is associated with Wallerian degeneration at both proximal and distal stumps .

• Seddon’s neurotmesis or Sunderlands’s third to fifth degree injury is associated with the potential for aberrant reinnervation after nerve regeneration.

• In Sunderlands’s fourth & fifth degree injuries only nerve repair can successfully establish continuity, but in first to third degree spontaneous recovery may occur.

Preoperative Evaluation and Diagnosis

• The Brachial Plexus Chart • This Chart must be completed at the time of primary

evaluation of a patient of brachial plexus injury.• This Chart is different for Right and Left Upper limb.• It Contains all the relevant clinical details along with

information obtained from radiological investigations such as x-ray or CT scan

chart

Present illness and past history• Etiology :- Traumatic vs Spontaneous

Static Vs Progressive• Conscious level at the time of trauma • Associated injuries• Previous surgical intervention• Characteristic of pain• This information aids in classifying the degree and extent of

injury and in determining the need for surgery and procedure

• A history of shoulder dislocation or glenoid fracture is associated with high incidence of infraclavicular brachial plexus injury whereas with a history of cervical spine injury root injuries are more common.

• Extreme Causalgia is often seen in patients with root avulsion because of injury to the spinal cord and is more commonly seen in lower root (C8-T1) avulsion because they are richest in sympathetic fibers.

• The pain typically has no precise distribution and is described as an electric shooting pain that continues for a short duration (seconds) and Resolves spontaneously.

• The pain is recurring , can be induced by cold temperature and can sometimes be relieved by psychological measures such as concentrating on other tasks or in some by posture or massage.

• This pain is called DEAFFERENTATION PAIN

• Also known as root shooting pain it is poorly tolerated and may persist for ever but usually reduces in intensity 6 months after the accident.

• This pain is more intolerable in elderly patients and is not amenable to reconstructive treatment due to inability of these patients to undergo proper rehabilitation.

• The patient may present with the following symptoms:• Pain, especially of the neck and shoulder. Pain over a nerve is

common with rupture, as opposed to lack of percussion tenderness with avulsion

• Paresthesias and dysesthesias• Weakness or heaviness in the extremity• Diminished pulses, as vascular injury may accompany traction

injury

MoTOR Examination-Medical Research Council (MRC) Scale for Muscle Strength

• Grade 5: Muscle contracts normally against full resistance.• Grade 4: Muscle strength is reduced but muscle contraction

can still move joint against resistance.• Grade 3: Muscle strength is further reduced such that the joint

can be moved only against gravity with the examiner's resistance completely removed. (As an example, the elbow can be moved from full extension to full flexion starting with the arm hanging down at the side )

MoTOR Examination• Grade 2: Muscle can move only if the resistance of gravity is

removed. As an example, the elbow can be fully flexed only if the arm is maintained in a horizontal plane.

• Grade 1: Only a trace or flicker of movement is seen or felt in the muscle or fasciculations are observed in the muscle.

• Grade 0: No movement is observed

• This system is clinically modified to provide additional information ie

• M5 – Strength against four finger resistance (by the examiner)• M4 – Strength against one finger resistance of the examiner

longer than 30 seconds• M3+ - Strength against one finger resistance of the examiner

shorter than 30 seconds• M3 – strength against gravity• M4 is recognized as the useful muscle strength

Brachial Plexus - Neurologic levels C5 – T1Neurologic Level C5

• The muscles found within this myotomal pattern are the deltoid and the biceps brachii. Because the latter is also innervated by C6, the deltoid is the most "pure" C5 muscle. The deltoid’s most powerful motion is abduction. One of the most commonly used tests for shoulder abduction is to instruct the patient to flex the elbow at 90 degrees, then offer gradual resistance to abduction until determining the extent of resistance he/she can overcome

Neurologic Level C6• The biceps brachii is innervated by C5 and C6. C6 also

innervates the most powerful wrist extensors, carpi radialis longus and brevis, which do radial extension. The ulnar extensor, extensor carpi ulnaris, is innervated by C7.

Neurologic Level C6• To test for wrist extension, stabilize the patient’s forearm with

the palm of your hand on the anterior aspect of the wrist. With the patient’s wrist in full extension, place the palm of your free hand over the posterior aspect of the patient’s hand and try to force it out of extension. If no damage is present, the patient will be able to resist movement. If C6 is damaged, ulnar deviation will occur.

Neurologic Level C7:• The muscles found within this myotomal pattern are the

triceps, wrist flexors and finger extensors. The triceps muscle primarily does elbow extension. A common test for this action is to ask the patient to fully flex the arm. Stabilize the patient’s arm just above the elbow and ask him/her to slowly extend it. Before the arm reaches a 90 degree angle, begin to offer firm, constant resistance until discerning the maximum resistance he/she can overcome

Neurologic Level C8• The muscles found within this myotomal pattern are finger

flexors—flexor digitorum superficialis, flexor digitorum profundis, and the lumbricals. To test for finger flexion, the patient fully flexes his/her fingers at all joints while you curl your fingers into them. Ask the patient to resist your attempt to pull his/her fingers out of flexion. A normal response is for all joints to remain flexed

Neurologic level T1• The muscles found within this myotomal pattern are those

involved in finger abduction—dorsal interossei and abductor digiti quinti (5th finger)—and adduction—palmar interossei. To test for abduction, instruct the patient to abduct his/her fingers. Then pinch each set of fingers to try to force them together (index to the middle, ring, and little finger, the middle to the ring and little finger, and the ring to the little finger.)

• Note any significant weaknesses between pairs. Test both hand in order to compare the strength of each, and evaluate them according to the standardized grading scale for muscle strength. To test for finger adduction, ask the patient to extend his/her fingers and hold a piece of paper (or a rupee note) between two of his/her fingers. Then you pull it out. Test the other hand in the same manner and compare the strength of each

Additional Muscle tests• Levator scapulae Muscle :- • It lies anterior to the trapezius and can be palpated more

easily than the rhomboid muscle.• Both these muscles are innervated by the same nerve the

Dorsal Scapular Nerve C4-C5

• Clavicular And Sternal heads of the Pectoralis Major :-• The Upper and middle trunk or its divisions innervate the

clavicular head whereas the sternal head is innervated by the lower trunk

• Winging of sacpula :- • Seen mainly with weakness of serratus anterior but may also

be seen in weakness or atrophy of the rhomboid

Sensory Examination• This includes standard sensory tests and localization of the

Tinel’s sign• This examination is based on Medical research council scale

( S0 To S4) which has been modified for clinical application

Tinel’s sign• Tinel’s sign is an important clinical sign to determine the

location of a neuroma or to judge the regeneration of injured nerves.

• If the tinel’s sign remains fixed at a a point over a period of time this implies retardation of progressive regeneration and warrants surgical exploration

• If the same advances from supra to infraclavicular region and then to the arm and the forearm, a wait and see attitude is recommended

• A weak or absent Tinel’s sign in the neck region in the circumstance of total palsy usually indicates a total root avulsion.

• Percussion of the Erb’s Point ( a point just lateral to the clavicular insertion of the clavicular head of the Sternocleidomastoid) that is perceived as pain over the shoulder or ear is usually a false positive sign .

• It may reflect a neuroma of the cervical plexus or brachial plexus neurotization by cervical plexus sensory fibers

• Pain radiating down to or below the elbow on percussion over the Erb point in the neck is significant ( ie., positive Tinel’s Sign)

• During successive weeks• If Tinel’s sign becomes consistently positive but does not

move, a grade iv or v infraganglionic lesion is suspected and surgery is indicated.

• If Tinel’s sign becomes strongly positive and moves in a distal direction , a grade ii or iii lesion may be suspected with chances of at least partial spontaneous recovery

• If the tinel’s sign progresses without recovery ,there is grade iii lesion with internal or external compression and surgery is warranted.

Deep pressure sensation• Deep pressure sensation may be the only clue to continuity in

a nerve with no motor function or other sensation. Apply full pinch to the nail base and pull the patient's finger outward. Any burning suggests continuity of the tested nerve. When no burning is elicited, these examination findings are less helpful because a neuropraxia can persist for more than 6 months.

Location of Deep Pressure Test Affected Spinal Nerve Nerve Affected Cord

Thumb C6 Median nerve Lateral cord

Middle finger C7 Median nerve Lateral cord

Little finger C8 Ulnar nerve Medial cord

Horner Syndrome• Components :- Miosis, Ptosis , Anhidrosis and enopthalmos• Sign of sympathetic nervous system disturbance • Indirectly implies avulsion of T1 and C8 roots because the

sympathetic fibers from the T1-T2 Sympathetic ganglion are close to the preganglionic fibers of T1 and C8.

Vascular injury• Subclavian artery occlusion might indicate a supraclavicular

lesion whereas involvement of axillary artery may indicate involvement of the infraclavicular part.

• Briefly Horner’s sign , winging scapula, muscular atrophy of parascapular muscles and causalgia indicate preganglionic injury whereas Tinel’s sign in supraclavicular region, sweating in the palm and minimal movements of the joints may be evidence of the post ganglionic or more distal injury

Investigations – plain radiographs

• Plain films of the cervical spine, clavicle, scapula, chest, and upper extremity.

• Fractures of these areas, when present, provide rough estimates of the forces imparted to the neck, shoulder, arm, and brachial plexus.

• However, they do not necessarily localize or quantify the extent of damage.

• The presence of cervical spine fractures implies a high-energy injury.

• Both burst fractures and transverse process fractures are associated with proximal plexus injuries.

• The C4, C5, C6, and at times, C7 nerve roots are tethered to the cervical spine's transverse processes.

• Accordingly, transverse process avulsion fractures at these levels are strong evidence of preganglionic root injuries

• Inspiration and expiration AP views can be used to evaluate diaphragm activity. Elevation of a hemidiaphragm and its failure to move indicate phrenic injury and suggest proximal C5 injury.

• In anteroposterior (AP) chest radiography, specific attention should be directed to the distance between the spinous processes of the thoracic spine and the scapula. If the radiograph is not malrotated, an increase in this distance compared with the contralateral side may indicate scapulothoracic dissociation

Myelography

• The most reliable indicator of root avulsion is an absent root shadow on plain myelography

• A common sign of a root avulsion is a meningocele at the affected level; hence, myelography may best be delayed for 4 weeks so that any blood clot will not be dislodged by the study and the meningocele can be allowed to form

• A meningocele usually means that either a root is avulsed, or , if it is in gross continuity, it has intraneural injury that extends to a proximal level.

• The presence of a meningocele does suggest a force great enough to cause an arachnoidal tear; if this root is nonfunctional, then damage has usually extended proximally

• Therefore presence of a meningocele favors proximal injury while absence is a point against it

• Other significant myelographic findings include extravasation of dye into the subdural or epidural compartments, evidence of cord swelling acutely, or after some time, evidence of cord atrophy.

meningoceles at C6-7 (7th root) and C7-T1 (8th root)- arrows

• Based on Nagano’s classification myelographic findings are classified into six categories :-

• N :- Normal root sleeve shadow• A1 :-slightly abnormal root sleeve shadow with distinct root

and rootlet shadow but different from the opposite side• A2 :- shows an obliteration of the tip of the root sleeve with

visible root or rootlet shadow

• A3 :- Obliteration of the tip of the root with no root shadow visible

• D :- Defect instead of root sleeve shadow• M :- Traumatic Meningocele

Computed tomography (CT) scanning

• Plain CT scanning is very helpful in evaluating any cervical fractures, and should be obtained if fractures are suspected based on plain radiographic findings.

• CT scanning of the chest may reveal subclavian vessel injuries, scapular fractures, humeral fractures, and thoracic spine fractures

CT myelography (CTM)• Lower concentrations of contrast medium can be detected by

CTM than by standard myelography. • CTM may be better able to reveal small meningoceles, but

artifact from surrounding soft tissues may be problematic at the lower cervical levels

• The CAT scan slices should be fine enough to cover the course of a nerve root (2 mm)

• Diagnosis of root avulsion by CTM is based on absence of either one root (P : Partial avulsion) or both dorsal and ventral roots (A: complete avulsion)or presence of a meningocele (M)

Magnetic resonance imaging (MRI)

• MRI is the only technique that can be used to visualize the postganglionic brachial plexus.

• MRI is the current criterion standard for visualizing spinal cord injuries

• But MRI may not show all the detail on all the roots to preclude the need for a subsequent myelogram.

Angiography

• Both conventional angiography and magnetic resonance angiography (MRA) are valuable tools in evaluating any suspected vascular disruption

electrodiagnosis

1) Electromyography (EMG) • This can be helpful in the evaluation of root avulsion, by

providing evidence of deinnervational changes in the rhomboid and serratus anterior muscles

• Equally important is the examination of paraspinal musculature; deinnervational changes here indicate proximal damage because the paraspinal muscles are innervated by the proximally located posterior spinal branches

• Their involvement is indicative of a preganglionic lesion• Fibrillation potentials on EMG may suggest that the lesion is at

least axonometic.

Sensory nerve action potentials (sNAP)

• These are important in the evaluation of brachial plexus injuries, especially as regards cases of suspected root avulsion, as the sNAP can sometimes differentiate a preganglionic from a postganglionic injury

• Preganglionic injury, found proximal to the dorsal root ganglion, produces a complete distal sensory loss but preserves distal sensory conduction

• This occurs because the dorsal root ganglion, which is also avulsed, is still in contact with the peripheral nerve fibers.

• If the injury is postganglionic or both pre- and postganglionic, no sNAP will be obtained.

• Sensory studies are done by stimulating the hand in the C6 (thumb and index finger), C6-7 (index and long finger), and C8-T1 (little and ring finger) areas and recording from median, radial, or ulnar nerves more proximally

• If the stimulated area is anesthetic to touch, recording a sNAP indicates a preganglionic injury in the particular root

• This works best for assessment of C8 and T1 and less well for C6 and C7 due to overlap of interventional zones

Somatosensory evoked potentials (SSEPs)

• Somatosensory studies, performed by stimulating over the plexus at Erb's point and recording over the spinal cord and contralateral cortex, can also be used in the evaluation of plexus injuries

• Obtaining an evoked cortical response (ECR) is evidence that posterior roots are in continuity with the spinal cord, no guarantee is offered as to the clinical outcome

• Only a few hundred fibers need to be intact for a spinal evoked potential (SEP) or ECR to be obtained

• A positive response only ensures that a minimum of sensory spinal fibers is functioning.

• The failure to obtain an SEP or ECR may be more significant, as it implies injury to the more resilient dorsal root

• Unfortunately, neither a positive nor a negative response localizes the level of injury to the plexus

• Intraoperative SSEPs are useful in brachial plexus surgery. The presence of SSEPs suggests continuity between the peripheral nervous system and the CNS via the Dorsal Root Ganglion. SSEPs are absent in postganglionic or combined pre- and postganglionic lesions

• No single test can tell the surgeon whether the injured plexus requires surgical exploration or not .

• All the information gathered must be assimilated and analyzed within the context of presumed energy of the trauma.

Surgical treatment

• It is the treatment of choice for adult brachial plexus injury either closed or open.

• Factors in the surgical treatment algorithm include1) Timing of surgery (primary or delayed)2) The technique of dissection (supraclavicular or

infraclavicular)3) Selection of technique (Neurolysis, Neurorraphy, Nerve

grafting, Nerve Transfer,functioning free muscle transfer)4) Reconstructive Strategies ( priorities of reconstruction)

• The possibilities and result of brachial plexus microsurgical reconstruction differ widely according to following factors

• - Nature of lesion .Sharp lacerations carry best prognosis traction and radiation injuries worst.

• - The extent of injury• - The Age of lesion – The quality of results diminishes if the

interval between injury and repair exceeds two months

• The Nerves affected – longer peripheral nerves have sophisticated configurations running for long distances and wrong fiber orientation will result in poor recovery .

Goals of Treatment in Brachial plexus lesions • 1) Elbow flexion by biceps/brachialis muscle reinnervation• 2) Shoulder stabilization ,abduction,an external rotation by

suprascapular nerve reinnervation• 3) Brachiothoracic pinch (adduction of the arm against the

chest ) by reinnervation of the pectoralis major muscle• 4) Sensation below the elbow in the C5-C6 area by

reinnervation of the lateral cord

• 5) Wrist extension and finger flexion by reinnervation of the lateral and posterior cord

• Apart from these for patients with an injury limited to the upper roots (C5-C6) regaining elbow flexion and shoulder stability are priorities

Timing of surgery• Primary or immediate• Indicated in sharp penetrating injuries• Usually done immediately or within few days after surgery• Direct end-to-end neurorraphy is highly possible and excellent

results can be expected• The ‘golden period’ for primary end to end repair is 1 week

after which a nerve graft is usually required

• Direct repair of spinal nerve lesions can result in recovery of shoulder and arm muscles to M4, forearm muscles to M3orM3+ and hand muscles to M2 or less.

• In case of open gunshot injuries, the brachial plexus palsy is usually caused by peripheral heat or by cavitation shock with Sunderland First to Third degree usually predominating

• The majority of these palsies will improve within 6 months .• Immediate exploration for neural surgery is not indicated in

these cases

• In case of open traction injuries like the ones caused by conveyor belt or rolling machine, the brachial plexus injuries are rupture or avulsion type and the open wounds are seen usually in the axilla.

• Immediate primary repair of associated vascular lesions is the priority

• If the nature of brachial plexus injury is diagnosed at the time of initial exploration the recommended time for delayed repair of the plexus is 2-3 weeks after the first surgery to avoid the troublesome scars during dissection

Delayed repair• This is classified into 3 phases :-• Intentionally Early Delayed Repair :- within 3 weeks after

injury• Early Delayed Repair :- Within 1 month for established

diagnosis in case of open injuries or within 5 months for closed injury

• Late Delayed Repair :- after six months of injury

Intentionally early Delayed Repair

• The peak metabolic response of the cell body after trauma is seen at 2 to 3 weeks during the subacute phase.

• An intentional delay of this period is therefore done to allow maximal effect of central regeneration power at the time of repair.

• This concept though is more pertinent for peripheral nerves as in brachial plexus this delay may make primary repair impossible

Early Delayed Repair• Indicated in open injuries with established diagnosis also in

closed injuries where the level of injury is not ascertained and requires workup.

• Closed traction injuries are the most common brachial plexus injuries in traumatized adult patients.

• The management of these patients can be considered in six stages :-

• Stage1 :- Stabilization Stage (first Month)• This includes stabilization of vital signs, bone # or joint dislocation

• Stage 2 :- Diagnostic Stage ( Second month ) • Clinical examination and investigation to establish the diagnosis

of the lesion including the level. Physiotherapy is started to prevent soft tissue swelling , joint stiffness. Electric stimulation is started to slow down muscle atrophy. Psychological education is initiated before the surgery

• Stage 3 :- Surgery (3rd to 5th month)• Stage 4 :- Rehabilitation stage requiring at least two years• Stage 5 :- Late reconstructive stage :- usually during third and

fourth year post operatively.• Usual time for assessment of residual deformity and planning of

tendon transfer procedures.• Tendon transfers done too early (within two years ) after injury

will end with failed or useless results• Stage 6 :- Destination stage (fifth year postoperatively)

Late Delayed Repair • It is unwise to perform brachial plexus repair more than 6

months after injury• In chronic cases (1 year or more after injury) the muscles have

undergone a long time of denervation and atrophy and the muscle fiber has been replaced by connective tissue and fat.

• Nerve repair in such delayed cases is no more effective and represents at best an adjuvant procedure.

• If there is clean transection , a primary repair with neuroraphy is indicated

• If there is open injury with blunt trauma to the nerves and complicating factors such as vascular injury or fracture , it is advisable to deal primarily with the other injuries and to perform reconstruction of the brachial plexus as a secondary procedure

• If there is a closed injury in a brachial plexus lesion, an elective reconstruction of the brachial plexus may be planned after clarifying the diagnosis and excluding the possibility of spontaneous recovery

Technique For REPAIR• 1) NEUROLYSIS• 2) DIRECT NERVE REPAIR( Neurorraphy)• 3) NERVE REPAIR WITH NERVE GRAFT (free or Vascularized)• 4) NERVE TRANSFER • 5) FUNCTIONING FREE MUSCLE TRANSPLANTATION

NEUROLYSIS

• Indicated only in lesions in continuity and with preserved intraoperative nerve action potential (Sunderland First to Third degree lesions )

• It is used to free the lesioned nerve from scar and facilitate nutrition and scar growth

• Neurolysis may be A) External :- Epifascial epineurotomy or epineurectomyB) Internal :- Interfascicular Epineurectomy

NEUROLYSIS

• A split repair leaving the normal portion of the elements and resecting the nonconductive portion with nerve graft is sometimes required.

DIRECT NERVe REPAIR (Neurorraphy)

• This is possible only in sharply divided nerves.• It is essential that end to end anastamosis be performed

without tension• The golden time for end to end repair is is within 1 week for

supraclavicular lesions and 2 weeks for infraclavicular lesions.• The techniques for direct coaptation without tension include• A) Sufficient mobilization of respective nerve ends.

• B) Traction suture with 6-0 nylon from the epineurium of both stumps to the firm soft tissue on opposing sides or to fibrotic muscle fascia

• C) Internal group fascicular suture with 10-0 nylon and external trunk epineural sutures with 8-0 nylon.

• D) Post operative immobilization for at least 3 weeks.

Nerve grafting• It is the predominant technique employed in brachial plexus

Repair.• There are two types of nerve grafts • A) Free nerve Grafts• B) Vascularized nerve grafts.

• The sural nerve is the source of free nerve graft in most cases.• Other nerves used are :- • Medial cutaneous nerve of arm and forearm• Lateral cutaneous nerve of arm

• Superficial Radial nerve• Lateral femoral cutaneous nerve• Superficial peroneal nerve• Saphenous nerve and • Split Ulnar nerve

• The Out come of nerve grafting is influenced by the length of the graft used, scar tissue at wound site, no of grafts used and presence of healthy appearing proximal stump available for grafting.

Topographic orientation• The following inferences have been drawn regarding the

topography of the nerves for aid of the brachial plexus surgeon :-

• The anterior (ventral) segments of the spinal nerves carry fibers that mostly go to the lateral and medial cords.

• The posterior (dorsal) half of the spinal nerve give fibers that will be innervating structures depending on the posterior cord

• Nerve fibers of the suprascapular nerve are located in the region of 12 ‘o’ clock in C5

• Nerve fibers for the axillary nerve are located near 9 ‘o’ clock in C5 and C6, while those for the pectorals are at the anterior opposite side at 3 ‘o’ clock in C5-C8

• Those for musculocutaneous nerve are located at 1 to 2 ‘o’ clock to those of the pectorals

• The fibers of radial nerve are located at around 7 ‘o’ clock• Those for the median and ulnar nerve are located between

3 and 6 ‘o’ clock ,median nerve fibers lying above those of ulnar nerve

• In case of total root avulsion or lower plexus root avulsion (C8-T1+/-C7) ,the entire ulnar nerve from axilla to the wrist may be used as a vascularized nerve graft either pedicle or free.

• A pedicled vascularized ulnar nerve graft is based on the superior ulnar collateral vessels.

• It is usually harvested from the wrist , including the deep motor branch , the superficial volar digital branches & dorsal digital branches

• A free vascularized ulnar nerve graft can be harvested segmentally and transferred passing through a subcutaneous tunnel or through the prevertebral space.

• These grafts are frequently used in contralateral C7 elongation and transfer.

Nerve transfers• These provide an extraplexal source of axons to reinnervate

the distal part of the avulsed or irreparable brachial plexus damage.

• Care must be taken not to cause significant motor or sensory deficit at the donor sites while doing nerve transfers.

• Usual nerves used are :-• Phrenic, Spinal Accessory, intercostal, motor branches

of the cervical plexus, hypoglossal and contralateral C7

• Viterbo in 1994 noted good neurotization in a degenerated nerve after end to side coaptation to an innervated nerve.

• Apparently a denervated nerve posses such a stimulus to the axons that they start to sprout even if undamaged and even across intact perineurium

• The problem however is that there is no control whatsoever over which fibers shall start sprouting sensory or motor and if motor which function. This led to failure of this procedure.

Shoulder Abduction• Simultaneous transfer of two nerves phrenic and spinal

accessory either both to the distal C5 spinal nerve or both separately to axillary and suprascapular nerves

• If Phrenic nerve is injured or not available hypoglossal nerve is used instead .

• Cervical motor branches are used as an adjuvant and are usually transferred to the distal stump of the C5 spinal segment coupled with any of these techniques.

Elbow Flexion• Transfer of three intercostal nerves to musculocutaneous

nerve is preferred• A part of Ulnar nerve transferred to musculocutaneous nerve

in the upper is another preferred procedure.• It is quick and easy and has no significant sensory or motor

deficit associated.

Hand flexion and Sensation• Neurotization of the median nerve from either ipsilateral

spinal nerve (C5-C6) if available or contralateral C7 is preferred• A vascularized ulnar nerve graft is always required in both

these scenarios

Functioning free muscle transfer

• Mostly applied for elbow flexion and finger flexion and extension

Reconstructive strategies for different levels• PREGANGLIONIC ROOT INJURY• 1) Total root avulsion• Most common root injury encountered in adults • A single stage procedure is now preferred for total

reconstruction in early stage.• Contralateral C7 transfer to median nerve with use of

vascularized ulnar nerve graft for some hand function(finger sensation & finger flexion ) to be regained

• Intercoastal nerve transfer to the musculocutaneous nerve for elbow flexion and forearm back sensation and

• Phrenic nerve and spinal accessory nerve transfer for shoulder elevation

• After the patient has obtained hand function wrist and thumb fusion is performed to improve stability of the hand.

• Other procedures such as Fusion of shoulder may be required for final outcome .

• At the end of surgical and rehabilitation period hand prehension (grasp and sensation) shall become possible

• Four root Avulsion• C5-T1 root avulsion is usually associated with rupture of C5• If the proximal C5 fibers are grossly healthy it is preferable to

perform a transfer to anterior division of the upper trunk for elbow flexion or to the median nerve for hand function.

• If the integrity of the fibers is doubtful it is transferred to the posterior division of the upper trunk

• The spinal accessory nerve is also simultaneously transferred to the suprascapular nerve for more confident shoulder function

• Contralateral C7 transfer to median nerve can also be done in the same sitting to achieve hand function and obtain a total reconstruction by a single stage procedure.

• Three root avulsion• Combined C5-7 three root avulsions with intact C8-T1 is the

second most common type of root injury encountered.• The recommended procedures in these type of injuries are :- • Phrenic and spinal accessory nerve transfer for shoulder

abduction and • Intercostal nerve or part of ulnar nerve transfer for elbow

flexion

• Combined C7-T1 root avulsion is usually associated with rupture of upper trunks.

• By use of nerve grafts C5 fibers are transferred to the suprascapular and posterior division of the upper trunk for shoulder elevation

• The proximal c6 stump is transferred to the distal C8 spinal nerve or median nerve intentionally for hand function.

• Two root Avulsion• Combined C5-C6 :- multiple nerve transfers are recommended

ie ; for shoulder elevation transfer of spinal accessory to the suprascapular nerve combined with phrenic nerve transfer to the posterior division of the upper trunk.

• For elbow flexion transfer of three intercostal nerves to muculocutaneous nerve is routinely done.

• In combined C6-C7 root avulsions :- C5 root is usually ruptured.

• The proximal stump if healthy is transferred to the anterior division of the upper trunk for elbow flexion.

• Shoulder function is obtained as for C5-C6• If the proximal stump is of doubtful health it is transferred to

the posterior division of the upper trunk in addition to the Spinal accessory to suprascapular transfer for more predictable shoulder elevation

• Elbow flexion in case of doubtful C5 stump is obtained by intercostal nerve transfer to musculocutaneous nerve.

• Combined C8-T1 root avulsion usually occur along with C5-C7 rupture.

• Shoulder elevation is regained with nerve graft from C5 to the suprascapular nerve and posterior division of the upper trunk.

• C6 fibers are transferred to median nerve for motor and sensory hand function

• Elbow flexion is achieved by intercostal nerve transfer.

• Pure C8 and T1 root injury with intact C5,C6,C7 is very rare.• In these cases early exploration is not preferred and in later

stages tendon transfers are performed.• Two separate procedures are done• ECRL (C6) is transferred to extensor digitorum for wrist and

finger extension• FCR (C6) is transferred to FDP for finger flexion.• All the thumb joints are fused for it to work as a post.

• Single root avulsion :-• Isolated C5 – Nerve transfers with spinal accessory ,phrenic

and cervical motor branches en mass to the C5 spinal nerve will achieve good supraspinatus ,infraspinatus and deltoid muscle strength and obtain powerful shoulder abduction.

• C6 root avulsion is usually associated with C5 rupture .• Nerve grafts from proximal C5 stump are transferred to the

anterior division of the upper trunk for elbow flexion.

• Shoulder elevation involves transfer of phrenic nerve to posterior division of the upper trunk and spinal accessory to the suprascapular nerve.

• Single C7 root injury is usually associated with upper trunk rupture in which case only repair of the upper trunk is required.

• Isolated C8 And T1 injuries are not reported.

Post ganglionic• Disruption with neuroma formation is the main finding in this

type of injury• Rupture of C5,C5-C6,C5-C7, C5-C8 0r C5-T1 may be found.• Nerve grafting is always necessary• Pure post ganglionic injury is not uncommon.• Most cases were associated with other root injuries.• Such as rupture of C5-C6 associated with root injury of C7-T1

• Managed with primary repair or nerve grafts.• Bypass from the proximal segment to the distal nerve

branches is a controversial procedure advocated by some researchers.

Preclavicular and retroclavicular-trunks &upper division

• Rupture of upper trunk with Neuroma formation is the most common lesion.

• It is sometimes associated with the lesion of the middle trunk• Pure lesions of this zone are most common with less

association with other root injuries.• Selective nerve transfers are preferred instead of an upper

trunk to upper trunk mass cable graft due fear of aberrant reinnervation.

• C5-to posterior division of upper trunk and the suprascapular nerve and C6 to anterior division of the upper trunk with cable grafts is preferred method of reconstruction.

Infraclavicular brachial plexus injury• In closed injury of infraclavicular brachial plexus the extent

of nerve damage is variable ranging from simple isolated nerve injuries to lesions of all cords or all terminal branches .

• The incidence of vascular injury with axillary or subclavian artery rupture is high in these injuries.

• The nerve might be avulsed From the neuromuscular junction called distal avulsion.

• This is frequently seen with axillary and radial nerves but less commonly with other terminal branches.

Technique of exploration• Supraclavicular dissection:-• A C-shaped incision along the posterior border of the

sternocleidomastoid muscle curved laterally parallel to and above the clavicle is the standard incision for supraclavicular approach to the brachial plexus.

• Other Ancillary incisions may be required such as • extended neck incision for visualization of the spinal accessory

nerve, • a semicircular chest incision for exposure of the intercostal nerves

• An inframental incision to expose the hypoglossal nerve and • A contralateral neck incision for contralateral C7 spinal nerve

dissection and transfer

Key points for supraclavicular dissection

• Brachial plexus dissection never needs to cross the line medial to the internal jugular vein

• The transverse cervical artery or vein is preserved if possible• Abundant adipofascial tissue is present between the

omohyoid muscle and the brachial plexus .This contains rich lymphatic network . All the lymph ducts in this field need to be ligated or coagulated during dissection to prevent postop lymph leakage

• The fibrotic scalene muscles can be totally excised.• Each spinal nerve can be dissected upto the intervertebral

foramen to locate the more healthy proximal stump for diagnose true root avulsion.

• The phrenic nerve is located on the scalenus anterior muscle. Superior dissection along the course of phrenic nerve leads to the cervical plexus.

• The nerve beneath the transverse cervical artery is usually C5 or the upper trunk

• The nerve beneath the subclavian artery is C8 or the lower trunk.

• The first main branch from the upper trunk is Suprascapular nerve.The division beside the suprascapular nerve is the posterior division which goes in the posterior plane , the anterior division of the upper trunk is seen going in the anterior plane.

Infraclavicular dissection• For the Infra clavicular approach the incision is made just

along the deltopectoral groove .• It can then be extended upward to meet the supraclavicular

incision or down wards towards the medial sulcus of the biceps.

• Connection between the supraclavicular and infraclavicular incisions is easily obtained with out the need to osteotomize the clavicle.

• The clavicular head of the pectoralis major is detached

Infraclavicular dissection• The clavicle and the subclavius muscle are lifted by a rolled

gauge and the connection between the supra and infraclavicular fossae is established.

Infraclavicular dissection• The Chuang triangle is formed by the main branch of the

cephalic vein on one side and the clavicle on the other side. It is an avascular zone. From here under the subclavius muscle it is easy to find the suprascapular nerve which goes posterior to the scapular notch.

• The y shaped limbs from lateral and medial cords have the subclavian artery running below and beneath them. These limbs later become The median Nerve.

• The posterior cord lying posterior to the subclavian artery has two terminal branches, Bigger – radial , Smaller- axillary

• In the upper arm the musculocutaneous nerve can usually be found between the biceps and coracobrachialis muscle.

• The axillary nerve in the axilla can be found in the humeral neck ,above the tendinous portion of Teres major, accompanied by lateral circumflex humeral artery

incisions

For supraclavicular

For infraclavicular

To join the two incisions

Adjuncts To surgical technique• Pre operative preparation and informed consent• Post operative exercises to be taught• Detailed discussion about the prolonged course of treatment and

practical outcome• Positioning of the patient and magnification• Supine • Arm abducted on board and neck turned to opposite side • Arm is prepared and draped loosely to enable visualization of

effects of nerve stimulation

• Both lower extremities and contralateral neck mandible and hemithorax prepared for the possible need of nerve grafts.

• Avoidance of muscle relaxant ,prolonged surgery duration and need for frequent change of posture to be discussed with the anaesthesiologist

• At least 2.5 x magnification is recommended for the dissection of the brachial plexus

Postoperative management and rehabilitation• Immediate post operative splinting for three weeks• This is followed by retraining and rehabilitation.• This includes Physiotherapy to avoid joint stiffness, muscle

stimulation to avoid muscle atrophy, brain cognition, biofeedback and occupational therapy

• Patients should be examined every 3-4 months by the surgeon and twice a month by the physical therapist

• Electrical stimulation is encouraged for muscles twice at home.

• In case of intercostal nerve transfer passive shoulder elevation remains restricted to less than 90 degrees for 6 months

• ‘Induction Exercise’ is an important exercise for the patients with nerve transfer.

• For patients after intercostal or phrenic nerve transfer, as soon as the reinnervated muscle starts to move with deep breathing, the patients are directed to run, walk or climb hills to encourage numerous deep breaths which can induce further stimulation to the re innervated muscle.

• Similarly tongue to palate push up exercise in hypoglossal nerve transfer and shoulder adduction or grasp exercises of the contralateral or healthy limb in contralateral C7 transfer have the same effect.

• Due to these factors good results are obtained by individuals who are psychologically strong , ambitious and cooperate well in terms of the rehabilitation program.

• A permanent external orthosis to extend the IP joints of the fingers is often required for intrinsic palsy of the hand to improve final surgical results.

Surgical treatment of functional sequelae

• Palliative reconstruction can be considered when the functional sequelae persist after the maximal recovery , either by spontaneous recovery or after nerve reconstruction .

• Palliative reconstruction procedures include muscle transfer, functioning free muscle transplantation , tenodesis and arthrodesis

Muscle transfer to the ShoulderPectoralis major transfer Hidebrandt (1906)

Trapezius Muscle transfer Hoffa(1902), Saha (1967)Bateman (with acromion and spine of scapula en bloc)

Long head of triceps to acromion Sloaman

Short Head of biceps Ober , Hass, Davidson, Harmon

Latissimus Dorsi Shultze-Berge, L’Episcopo

Muscle transfer for elbow• Pedicled muscle transfers

Latissimus Dorsi Zancolli and mitre1973

Pectoralis major transfer Schottstaedt et al 1955

Triceps transfer Narkas 1989

Steindler transfer- Flexor pronator muscle transfer

Transposition of the common head of the forearm flexors to the humerus shaft in order to give better lever arm for flexion of the elbow joint.

• Free muscle transfer for elbow flexion• Used in delayed cases of more than 10 months , failed cases

after nerve transfer or grafting• In young patients.• Commonly used muscles are • Latissimus Dorsi• Gracilis • Rectus femoris• Pectoralis major (rare)

Technical considerations • Stability of the proximal joints• Antagonist of the transferred muscle• Selection of donor muscle• Suitable neurovascular anatomy of the donor muscle• Adequate strength and range of excursion of donor muscle• Suitable gross anatomy to fit the defect (muscle

length ,location of neurovascular bundle , and tendon availability)

• Minimal functional and cosmetic donor defect

Technical points• Dissection and transfer of donor nerve• Dissection and transfer of recipient vessel• Harvest of donor muscle• Suture of proximal attachment of the muscle • Noeurovascular anastomoses• Suture of distal attachment of the muscle in its correct tension

Double free muscle transfer for prehensile function• This double free gracilis transfer technique consists of five

established reconstructive procedures.• Exploration of brachial plexus a and repair of damaged nerves

if possible• The first free muscle transfer is for elbow flexion and finger

which is neurotized by the spinal accessory nerve• The second free muscle transfer is for finger flexion which is

neurotized by the 5th and 6th intercostal nerves

• A nerve crossing procedure using the third and fourth intercostal nerve to neurotize the motor branch of the triceps brachii done for elbow extension simultaneously along with second muscle transfer.

• The intercostal sensory rami coapted to the medial cord of brachial plexus to restore sensibility of the hand.

• It is imperative to achieve proximal joint stability before performing the procedure.

Humeroscapular arthrodesis• It is done in failed or neglected cases with glenohumeral

instability , in total or upper type paralysis with or without serratus paralysis but with patients in whom trapezius is normal.

• This procedure provides stability to the shoulder and improves range of shoulder motion depending on the strength of the scapulothoracic muscles

Outcome of treatment• Spontaneous recovery in adult brachial plexus

injury ,especially in high energy is rare but still possible .• This is especially true in lower plexus root injuries.• After successful nerve grafting for infraclavicular injuries

recovery can usually be expected to M4 for deltoid biceps or triceps ; M3+to M3 for forearm flexors or extensors (except extensor digitorum ,abductor pollicis longus, and brevis) &

• M2 or less for hand intrinsic muscles • In pure preclavicular and retroclavicular injury the results are

more unpredictable because of development of aberrant innervation.

• In root avulsion nerve transfer can obtain an average of 55 degrees of shoulder abduction (80%) ,M4 to M3 elbow flexion (around 80% by intercostal nerve graft) and M3+to M3 finger flexion (nearly 50% from contralateral C7 nerve transfer)

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