Brachial Plexus Injuries in Adults

Introduction

The brachial plexus prone for injury because of following reasons.

  • The upper limb is connected to the axial skeleton mainly by the soft tissues, with the only bone connection of upper limb to axial skeleton being the clavicle.
  • Supraclavicular portion of brachial plexus is relatively superficial.
  • The shoulder girdle has a wide arc of movement.

These factors increases the risk  injury especially to the brachial plexus.

History

Homer described brachial plexus injury in the duel between Hector and Teucrus in Iliad.

1947- Seddon described nerve grafting.

1961- Yeoman and Seddon described intercostal nerve transfer.

1966- SICOT congress in Paris reached a consensus to discourage surgery for BPI due to discouraging results.

1970s- Work by Millesi in Vienna and Narakas in Lausanne demonstrated the utility of brachial plexus reconstruction

Anatomy

  • Dorsal roots (sensory) and ventral roots (motor) unite to form the spinal nerve.
  • The spinal nerve divides into dorsal and ventral rami. Dorsal rami supply the muscles and skin of paravertebral region.
  • The ventral rami of C5-C8 and T1 merge and decussate to form the brachial plexus with variable contribution from C4 and T2 between the anterior and middle scalene muscles. The brachial plexus can be divided to roots, trunks, divisions, cords and individual nerves.
  • Trunks are formed in the interscalene triangle. Cords are formed distal to the outer margin of first rib. Cords are named according to their relationship to the second part of axillary artery situated posterior to the pectorals minor.
  • C5 and C6 ventral rami unite to form the upper trunk (C5-6). C7 continues as middle trunk  (C7). C8 and T1 unite to form the lower trunk (C8-T1).
  • Each trunk divides into anterior and posterior divisions. The anterior divisions of upper and middle trunk unite to form the lateral cord (C5,6,7). The anterior division of lower trunk continue as medial cord (C8-T1). Posterior divisions of upper, middle and lower trunks unite to form the posterior cord.
  • Individual nerves may arise from the roots, trunks or cords of brachial plexus.
  • No nerves arise from the divisions of brachial plexus.
  • The phrenic nerve, long thoracic nerve and dorsal scapular nerve arises from the roots.
  • Long thoracic nerve arises from C5, C6 and C7 roots and supplies the serratus anterior.
  • Dorsal scapular nerve arises from C5 root and supplies the levator scapulae and the rhomboids major and minor.
  • The nerve to subclavius (C5) and suprascapular nerve (C5,6) arise from the upper trunk.
  • Suprascapular nerve (C5,6) supplies the supraspinatus, infraspinatus and teres minor.
  • Lateral cord (C5,6,7) gives rise to lateral pectoral nerve, musculocutaneous nerve  and lateral root of medial nerve (Mnemonic- LML).
  • Medial cord (C8,T1) gives rise to medial cutaneous nerve of arm, medial cutaneous nerve of forearm, medial root of median nerve, medial pectoral nerve and ulnar nerve (Mnemonic- MMUMM).
  • Posterior cord gives rise to subscapular nerve, thoracodorsal nerve, axillary nerve  and radial nerve (Mnemonic- STAR).

Pathology

  • Majority of brachial plexus injury (BPI) are due to traction.
  • Traction injury can stretch the nerve leaving it in continuity, rupture the nerve keeping it amenable for repair or avulse the nerve roots from the spinal cord making repair impossible.
  • Cell bodies of motor nerves are located in the anterior horn. The cell bodies of sensory nerves are located in the dorsal roots ganglion.
  • Continuity with the cell body and axoplasmic circulation is essential for survival and functioning of axons. In preganglionic injuries the sensory nerve fibres retain the connection to the cell bodies, but not the motor axons. Hence sensory fibres do not undergo wallerian degeneration in preganglionic injuries, but motor fibres do.
  • As the cell body of motor fibres are situated within the anterior horn of spinal cord; motor fibres undergo wallerian degeneration in all brachial plexus ruptures and avulsions. This is the anatomic basis of normal sensory nerve conduction and abnormal motor conduction on neurophysiological studies in preganglionic injuries.
  • Macroscopically, injuries of brachial plexus may be lesions in continuity or lesions in discontinuity.
  • Microscopically, lesions in continuity may be with neuroma (axonotmesis) or without neuroma (neuropraxia).
  • Lesions in discontinuity may be ruptures or avulsions. Ruptures are neurotmesis.
  • Avulsions are detachment of dorsal and ventral roots from the spinal cord. Avulsions are preganglionic injuries. Avulsions do not recover and are not repairable as well. As recovery and repair are impossible, treatment is by reconstruction by nerve transfers (neurotization) and other reconstructive procedures.
  • Ruptures are more common in the upper roots and avulsions are more common in the lower roots.

Mechanism of injury

  • Injuries may be due to crushing, traction or compression.
  • Traction is the most common mechanism injury in the brachial plexus. Downward traction affects upper roots and upward traction affects the lower roots first.
  • Traction can lead to lesions in continuity, rupture of nerves and avulsion of roots from the spinal cord.
  • Automobile accidents are the leading cause of BPI. Among the automobile accidents, BPI is most common after motorcycle crashes. As the rider hits the ground the head and the shoulder are forcefully separated leading to traction injury to the brachial plexus.
  • Other mechanisms of injury are fall from height, fall of heavy objects on the unprotected shoulder, penetrating injuries, gunshot injuries and direct compression or laceration from bone fragments in clavicle fractures.

Classification

  • Traumatic brachial plexus palsy can be classified in many ways. It may be classified as open or closed, total or partial, supraclavicular or infraclavicular and as preganglionic or postganglionic or combined. The most important differentiation that influence the treatment and  prognosis is into preganglionic injuries and postganglionic injuries as preganglionic injuries are not amenable for repair.
  • 75% of BPI are supraclavicular and 25% are infraclavicular. 10% of supraclavicular injuries are double level lesions with supraclavicular and infraclavicular injury.
  • 80% of supraclavicular injuries involve the whole plexus, 2-3% involve C8 and T1 and the rest involve C5,6 and (7).
  • Upper roots are usually ruptures and lower roots are commonly avulsions.

Clinical Features

Introduction

  • Aim of examination is to;
    • Detect BPI
    • Identify the roots involved
    • Identify the level of lesion
    • Distinguish between preganglionic and postganglionic injuries
    • Identify the muscles paralysed
    • Identify functions lost
    • To note signs of recovery.
  • Patients present with paralysis, paraesthesia, pain and physical disability.
  • Physical signs may be due injury to the plexus itself or adjacent structures.
  • The pattern of neurologic findings may fit a root, trunk, division, cord or nerve pattern.
  • Careful charting of sensory and motor changes and serial examination guide to the localization of injury and its severity.
  • Certain findings should be carefully looked for as they are easy to miss but have a profound effect on the prognosis and management as they are indicative of preganglionic injury.
  • Signs of preganglionic injury are the following.
  • Horner’s syndrome due to sympathetic system involvement.
    • Lack of sweating on the same side of face
    • Constricted pupil
    • Psuedoptosis due to paralysis of Muller’s muscle
    • Enophthalmos
  • Paravertebral muscle wasting indicative of dorsal rami injury.
  • Weakness of rhomboids (dorsal scapular nerve arises from roots)
  • Semidiaphragmatic paralysis (phrenic nerve arises from roots)
  • Serratus anterior palsy causing scapular winging (long thoracic nerve arises from roots)
  • Pyramidal tract signs such as up-going plantar response in the lower limb (spinal cord injury)
  • Pain in an anaesthetic limb
  • Transverse process fracture on x-ray
  • Histamine test positive (normal axon reflex)
  • Absence of Tinel’s sign in a grossly paralytic limb also may also indicate avulsion.

History

  • Ask the mechanism of injury. Ask whether patient was wearing helmet in case of motorbike accident.
  • Ask whether patient was wearing seatbelt in case of motorcar accident.
  • Ask for any loss of consciousness.
  • Document the occupation, handedness and circumstances of injury.
  • Ask for signs of recovery.
  • Document the location, character and time of onset of pain.
  • Document the functional disabilities.
  • Symptoms of brachial plexus injury may be paralysis, altered or absent sensation and pain.
  • Pain in an anaesthetic limb is common in brachial plexus avulsions and is considered as  a poor prognostic sign. This pain of deafferentation may not be present immediately after injury. It causes unremitting burning or crushing pain worse at night.

Inspection

  • Look for scars, muscle wasting especially of paraspinal muscles, periscapular area, deltoid and the thenar and hypothenar muscles.
  • Look for deformities such as claw hand, winging of scapula, dipping of shoulder, sulcus sign due to inferior subluxation of shoulder.
  • Look for trophic changes.
  • Look at the size of eye, size of pupil, psuedoptosis, dryness of ipsilateral side of face to detect Horner syndrome.

Palpation

  • Feel the bones of shoulder girdle to identify thickening, shortening, deformity, bone spurs or malunion. Feel the ribs to identify rib fractures especially if intercostal neurotization is contemplated.
  • Palpate the supraclavicular and infraclavicular areas for any scarring, pulsatile swelling or TInel sign.
  • In the supine position with the head turned away, elicit Tinel sign over the intervertebral foramen by tapping along the course of brachial plexus from the distal to proximal direction.
  • Positive Tinel sign indicates rupture than avulsion injury and denotes that intra-plexus donors are available if it correlates with intra-operative findings.

Auscultation

  • Auscultate for bruit over subclavian artery.

Movements

  • Document the passive range of movement of shoulder, scapulothoracic joint, elbow, wrist, fingers and neck.

Neurological Examination

  • Document the power of all muscles of the involved extremity.
  • Do a sensory mapping. Note areas with lack of sensation, dysesthesia and paraesthesia. Note the pain threshold in various dermatomes. Sensory examination should include light touch, moving touch, moving and static two-point discrimination, pain and temperature.
  • Look for upper motor neurone findings such as up-going plantar response in the lower limb to rule out root avulsions from spinal cord. Watch how the patient does common functions such as undressing to note the functional deficit and how the patient has adapted to it.
  • C5,6 palsy is called Erb-Duchenne palsy and the C8-T1 palsy is called Dejerine-Klumpke palsy.
  • Isolated lesions of trunk are rare, anterior trunk lesions lead to flexor weakness and posterior cord lesions lead to extensor weakness.
  • Lateral cord lesions lead to weakness of elbow flexion, wrist flexion and forearm pronation with sensory loss over anterolateral forearm and hand.
  • Medial cord lesions lead to weakness of finger flexion and intrinsic paralysis with relative sparing of finger extension and sensory loss over medial aspect of arm and forearm.
  • Posterior cord lesions lead to paralysis of subscapularis, latissimus dorsi, muscles supplied by radial nerve, axillary nerve and sensory loss over posterior and lateral aspect of arm.
  • Associated injuries are common. Head injuries, chest injuries, fractures  and dislocations of shoulder girdle and vascular injuries occur in decreasing incidence. Subclavian artery injuries occur in 10-15% of patients with BPI and may be missed due to rich anastomosis around the shoulder.
  • Any signs of recovery should be carefully looked for and documented to assess progress in serial examination.

Medical Research Council Grading System for Nerve Recovery

Motor recovery

M0 – No contraction

M1 – – Return of perceptible contraction in the proximal muscles

M2 – Return of perceptible contraction in the proximal and distal muscles

M3 – Return of function in proximal and distal muscles to such a degree that

all important muscles are sufficiently powerful to act against gravity

M4 – All muscles act against strong resistance, and some independent

movements are possible

M5 – Full recovery of all muscles

Sensory recovery

S0 – No recovery

S1 – Recovery of deep cutaneous pain

S1+ – Recovery of superficial pain

S2 – Recovery of superficial pain and some touch

S2+ – As in S2, but with overresponse

S3 – Recovery of pain and touch sensibility with disappearance of

overresponse

S3+ – As in S3, but localization of the stimulus is good, and there is imperfect

recovery of two-point discrimination

S4 – Complete 

Investigations

Investigations may be neurophysiological studies or imaging studies.

Neurophysiological studies

  • Neurophysiology uses nerve conduction studies and electromyography.
  • They are not useful in the initial weeks of injury.
  • Denervation potentials on EMG are the first changes observed by neurophysiology, usually detectable after 3 weeks of injury.
  • EMG should include paravertebral muscles as denervation indicates avulsion injury.
  • Preserved sensory nerve conduction in the presence of sensory loss along with impaired motor conduction in an anaesthetic limb is a bad prognostic sign suggestive of avulsion injury.
  • Serial examination is required to identify recovery.
  • Large polyphasic potentials on attempted voluntary contraction of the muscle under study by EMG is the first sign of recovery on electrophysiological study.

X-Ray

  • On the x-ray of cervical spine look for fractures of transverse process as it indicates nerve root avulsions.
  • Rib fractures may indicate intercostal nerve injury which may limit the availability of donors for transfer.
  • Look for clavicle and shoulder fractures.
  • Scapulo-thoracic dissociation may be seen in high velocity injuries and suggest root avulsions and vascular injury. Scapulothoracic dissociation is diagnosed in presence of sternoclavicular dislocation, acromioclavicular dislocation, distracted clavicle fracture, laterally displaced scapula and pathognomic increased scapulothoracic ratio (distance from medial border of scapula to the thoracic vertebra) of more than 1.1.
  • On the chest x-ray look for elevation of hemidiaphragm suggestive of phrenic nerve injury.

Myelography

  • CT myelography is the current gold standard for detection of psuedomeningocoele with a positive predictive value of 95%.
  • It has 95% sensitivity and 98% specificity.
  • Major disadvantage of CT myelography is that it evaluates only the roots.
  • CT myelography is best done after the first month as blood clots and edema may interfere with pooling of dyes.
  • Psuedomenigocoele is suggestive of root avulsion but not diagnostic as dural tear can occur without root avulsion and root avulsion can occur without dural tear.

Magnetic Resonance Imaging

  • Standard MRI can detect psuedomeningocoele only in 52% of cases due to pulsations of CSF, but it helps in evaluating the entire plexus.
  • Hence high field strength MRI with multiplanar image acquisition and thin slices is required for evaluation of brachial plexus injuries.
  • Presently 3 Dimensional MR myelography is used to assess preganglionic lesions and MR tractography (neurography) is used for postganglionic injuries, ideally by using 3 Tesla MRI.
  • Phased array coil technology, parallel imaging by multi-element RF coils to improve signal-noise ratio, volumetric acquisition with multiplanar and curved-planar reformations have further improved the utility of MRI. 3D T2 SPACE (Sampling Perfection with Application of Contrast Enhancement) sequences are preferred to avoid artefacts due to CSF pulsations.
  • Diffusion tension tractography is experimental at present and may be useful for evaluation of root avulsions as it can demonstrate the microarchitecture of nerve and fibre tracts.
  • MRI can show denervation changes in the paraspinal muscles and spinal cord abnormalities in presence of root avulsions.

Management

  • Even with the recent advances in microsurgery and rehabilitation, the outcome of treatment is far from satisfactory from the viewpoint of an unrealistic patient. This is especially true especially with regard to the hand function. The surgeon may be happy with active elbow flexion after nerve transfer but patient may not be. Hence the patient should be counselled properly to have a realistic expectation regarding the goals of treatment.
  • Treatment options depends on the duration, clinical and diagnostic findings and the level, pattern and nature of the injury.
  • During the preoperative phase, physiotherapy should be given to maintain the range of motion and to strengthen remaining muscles.
  • Advice be given to prevent injury to denervated areas.
  • Limb elevation and compressive bandage may be needed in presence of chronic edema.
  • Sling or brace used to support the limb to prevent distraction by the weight of the limb.
  • Gabapentin, carbamazepine or pregabalin may be useful for intermittent neuropathic pain. Constant neuropathic pain may respond to amytryptline.
  • Dorsal root entry zone rhizotomy may be done in persistent neuropathic pain.  In patients with intractable pain in an anaesthetic limb, neurotization using intercostal nerves can be of use for pain relief.
  • Do EMG at 4 weeks to assess recovery, may be repeated at 4-6 weeks.
  • CT myelogram or MRI of brachial plexus is done at 6 weeks to rule out avulsions and ruptures.
  • Surgical exploration is the most accurate modality to ascertain the plexus lesions. For significant supraclavicular injuries early exploration has definite diagnostic and therapeutic advantages.
  • Procedures are done depending on the duration of injury, roots involved, nature of injury and aim of surgery.
  • The surgical options are the following
    • Neurolysis – External or internal neurolysis
    • Nerve repair
    • Nerve grafting
    • Nerve transfer
    • Secondary reconstructive procedures such as arthrodesis, free muscle transfer or tendon transfer.
  • Indication for emergency surgery are open penetrating injuries and vascular injury.

Timing of Surgery

  • Current trend is towards early surgery. Patients are observed initially for upto 8-10 weeks for signs of spontaneous recovery. A baseline nerve conduction study and EMG is done at 4-6 weeks and repeated every 6 weeks as necessary. Patients with features of preganglionic injuries may be operated at this time.
  • Preganglionic injuries are operated early around 2-3 months. Postganglionic injuries are operated at 5-6 months if there are no signs of recovery.
  • Surgery at the earliest advised for whole arm type traumatic brachial plexus palsy involving C5 to T1.
  • Absence of recovery within 6-8 weeks and non-anatomic recovery are considered as indications for surgical exploration.
  • Early surgery advised if the recovery occurs non-anatomically in the distal muscles than proximal muscles. Iatrogenic injuries to be explored early. Relative contraindications for nerve repair are age over 50 years, duration more than 9 months.
  • Recovery of individual roots should be assessed clinically and electrophysiologically.
  • Surgery advised at 3 months if there is no clinical or electrophysiological evidence of recovery.
  • Timing of surgery depends on the pathology.
  • Goal of treatment depends on the remaining function, timing of surgery and the nature of injury.

Aim of Surgery

  •  Aims of surgery are stable shoulder with abduction and external rotation, elbow flexion and as much hand function as possible.
  • Priorities of reconstruction are restoration of elbow flexion followed by shoulder stability, shoulder abduction and external rotation and scapular stabilisation.
  • Sensation of the medial aspect of forearm and hand is also important for protection against injury.
  • It is achieved either by repair or reconstruction. Postganglionic injuries are repaired and preganglionic injuries are reconstructed.
  • The results of surgery vary greatly. The result of surgery to achieve shoulder abduction is 75%, for elbow flexion 48%, for elbow extension 30%, finger flexion 35% and finger extension 15%.

Aim of treatment

Aim of treatment

Technical points on surgical treatment

  • Surgery is done under light general anaesthesia and without muscle relaxants to increase the sensitivity of intra-operative nerve stimulation.
  • Incision made along the posterior border of sternocleidomastoid. Identify the phrenic nerve along the anterior border of scalene anterior muscle, trace it proximally to identify C4 and C5. Identify the other roots caudally. Explore the nerves to identify the level, extent and type of injury.
  • Exploration may reveal lesions-in-continuity, ruptures and avulsions.
  • Avulsions may appear normal on exploration as the lesion is intra-vertebral.
  • Roots that are pale in appearance, empty on palpation and not excitable are avulsed.
  • Lesions-in-continuity are hard on palpation and may show thickening.
  • Intra-operative nerve stimulation is used for further evaluation to identify the nerves and the nature of lesion.
  • Direct neuroelectrical stimulation is used.
  • The C5, C6 and C7 roots, upper trunk, middle trunk and the anterior and posterior divisions are stimulated and the compound muscle action potentials are recorded from the triceps, biceps, extensor digitorum communis, extensor indicis and flexor carpi radialis.
  • Nonconducting lesions-in-continuity are resected and repaired. Lesions in continuity which are conducting may either be left alone or treated by microneurolysis.
  • Neuromas resected until normal fascicles are seen.
  • Carbonic anhydrase or cholinesterase staining can be used intra-operatively to differentiate between motor and sensory fibres but are time consuming and often impractical.
  • Muscle function restoration can be achieved by nerve repair, nerve grafting or nerve transfer.
  • Ruptures are treated by direct repair or nerve grafting.
  • Nerve repair is done if repair can be done without tension. Direct nerve repair is not usually possible.

Nerve Graft

  • Nerve grafting is the commonest type of repair done in brachial plexus injury.
  • Sural nerve is the most commonly used nerve graft followed by medial cutaneous nerve of forearm and sensory branch of median nerve.
  • Recovery depends on the health of the proximal stump, amount of gap and the duration of injury. Nerve graft should be 20% longer than the gap. Nerve graft is required in presence of gap or scarring of bed.
  • Nerve grafts may be cable grafts, trunk grafts and vascularised nerve grafts.
  • Cable grafts are usually preferred as they have better outcomes due to more rapid vascularization.
  • Nerve graft should be 20% longer than the nerve gap to allow tension-free repair.
  • Vascularised grafts are indicated if the bed is scarred and avascular or if the nerve defect is large.

Neurotization

  • Avulsions are treated by nerve transfers or free functioning muscle transfers.
  • Neurotization is transfer of a normally functioning nerve to achieve functioning of  the target muscle.
  • Coaptation of healthy proximal part of a healthy nerve to the distal stump of a denervated nerve is done.
  • It sacrifices the function of a less important muscle to innervate a functionally more important muscle.
  • The donors for nerve transfer may be intra-plexus, extra-plexus or contralateral plexus.
  • It is done in preganglionic injuries as there is no chance of recovery.
  • Ideally the donor nerve should be a pure motor nerve such as spinal accessory nerve.
  • Ideal timing for neurotization is within 6 months of injury.
  • Donor may be intra-plexus or extra-plexus.
  • Intra-plexus donors may be medial pectoral nerve or part of ulnar nerve.
  • Extra-plexus donors may be phrenic nerve, intercostal nerves, spinal accessory nerves or contralateral C7 root.
  • Avoid use of intercostal and phrenic nerves together to avoid the risk of respiratory compromise.
  • Greater the number of axons in the donor nerve, better is the chance of recovery.
  • Coaptation may be end-to-end or end-to-side.
  • End-to-side neurorrhaphy is  attachment of proximal end of the distal stump of denervated nerve to the side of a healthy nerve to preserve function. It is seldom used.
  • Neuromuscular neurotization is direct transfer of motor fascicles into the paralysed muscle.
  • If possible avoid nerve grafts for neurotization as direct neurotization gives better results than when done with nerve grafts.
  • Best motor donor nerve should be used for restoration of elbow flexion.
  • Pure motor nerves like spinal accessory nerve is considered as better donors.
  • Neurotization should be done as close as possible to the motor end plates of target muscles to ensure early and reliable recovery.
  • Oberlin transfer is transfer of one or two functioning fascicles of ulnar nerve or median nerve  to the motor branch of musculocutaneous nerve to the biceps. Oberlin described transfer of 10% or 2 fascicles of ulnar nerve to the motor branch of biceps to restore elbow flexion.
  • One spinal accessory nerve or 2-3 intercostal nerves may need to be transferred to musculocutaneous nerve to achieve grade 3 power elbow flexion.
  • Spinal accessory neurotization is mainly used for shoulder function and intercostal nerve or partial ulnar nerve for elbow flexion.
  • Intercostal nerve transfer usually uses 3rd, 4th and 5th intercostal nerves.
  • Spare the 4th intercostal nerve in women.
  • Patients should not have had rib fractures, thoracotomy or intercostal tube insertion.
  • Uncontrolled elbow flexion during coughing, sneezing and yawning seen in 10%.
  • Advantage of spinal accessory nerve is it being a pure motor nerve.
  • The portion distal to trapezius ramus used. Usually needs nerve grafting. Usually used for shoulder stabilisation.
  • C7 root can be sacrificed without significant functional loss.
  • Millesi found that useful arm function was achieved in 72% after neurolysis, 67% after neurorrhaphy, 70% after nerve grafting and 41% after nerve transfer.

Number of axons in different peripheral nerves

Number of nerve fibers

Preferred reconstructions

C5,6 lesions

  • Spinal accessory distal branch to suprascapular nerve to restore abduction .
  • Thoracodorsal or subscapular nerve to axillary nerve to restore deltoid function
  • Oberlin transfer of ulnar fascicle to musculocutanoeus nerve to restore elbow flexion.

C8-T1 lesions

  • Brachialis branch of musculocutaneous to anterior interosseous nerve using grafts
  • Tendon transfers

Complete plexus injuries

  • Supraspinatus and biceps are primary target muscles and the deltoid and the triceps are secondary target muscles to restore function.
  • Patients with good hand function with flail and painful shoulder may be good candidates for shoulder arthrodesis. Patient should have good scapulo-thoracic function with intact acromio-clavicular joint and sternoclavicular joint. Arthrodesis done in 300 flexion, 300 internal rotation and 200 abduction.

Functioning free muscle transfer 

  • Patients with failed primary repair and late presentations may be treated by free muscle transplantation using gracilis.
  • A useful option in patients who present late or in those with failed reconstruction with muscle atrophy and motor end plate degeneration.
  • Contralateral Latissimus dorsi, rectus femoris and sartorius are the common donor muscles.
  • The free muscle is innervated by intercostal nerves. Done if there is no local muscle available for transfer.

Secondary procedures 

  • Done to augment specific functions in those who have had brachial plexus reconstruction.
  • Delayed presentation is another indication for secondary procedures.
  • These procedures may be arthrodesis, osteotomies, tendon transfers or muscle transfers.
  • Examples of tendon transfers in shoulder include transfer of clavicular and acromial insertion of trapezius to the humerus to restore abduction, transfer of sternocostal head of pectorals major to restore forward flexion.
  • Elbow flexion can be restored by transfer of pectorals major or pectorals minor.
  • Elbow flexion can also be restored by Steindler flexorplasty by proximal transfer of common flexor origin. The common flexor origin is shifted from medial epicondyle to 5-6cm proximally to increase the lever arm for elbow flexion by these group of muscles. Brunelli modified the procedure by avoiding flexor digitorum superficialis to prevent pronation and excessive finger flexion during active elbow flexion.

Tendon transfers

Shoulder

L’ Episcopo- Latissimus dorsi transfer to improve external rotation

Trapezius transfer to deltoid to restore abduction

Elbow flexion

Pectoralis major to biceps- Clark procedure

Latissimus dorsi to biceps

Proximal transfer of common flexor origin- Steindler’s procedure

Triceps to brachialis transfer

Prognosis

  • Recovery depends on the interval between injury and surgery, length of nerve graft and type of functions lost.
  • Denervation time is the most important prognostic factor followed by age.
  • Interval of more than 9 months after injury usually is associated with poor prognosis.
  • Graft length of more than 10cm is associated with poor prognosis. More distal deficits such as hand function carry poor prognosis.
  • Prognosis also depends on the health of proximal stumpOberlin described transfer of 10% or 2 fascicles of ulnar nerve to the motor branch of biceps to restore elbow flexion.

Further Reading

  1. Terzis, J. K., Vekris, M. D., and Soucacos, P. N. Outcomes of brachial plexus reconstruction in 204 patients with devastating paralysis. Plast. Reconstr. Surg. 104: 1221, 1999.
  2. Brunelli, G., and Brunelli, G. Preoperative assessment of the adult plexus patient. Microsurgery 16: 17, 1995
  3. Narakas, A. O. Thoughts on neurotization or nerve transfers in irreparable nerve lesions. Clin. Plast. Surg.11: 153, 1984.
  4. Narakas, A. Surgical treatment of traction injuries of the brachial plexus. Clin. Orthop. 133: 71, 1978.
  5. Millesi, H. Brachial plexus injuries: Management and results. Clin. Plast. Surg. 11: 115, 1984. Oberlin, C., Beal, D., Leechavengvongs, S., et al. Nerve transfer to biceps muscle using a part of ulnar nerve for C5–C6 avulsion of the brachial plexus: Anatomical study and report of four cases. J. Hand Surg. (Am.) 19: 232, 1994.
  6. Millesi, H. Brachial plexus injuries. Clin. Orthop. 237: 36, 1988.
  7. Steindler, A. A muscle plasty for the relief of flail elbow in infantile paralysis. Interstate Med. J. 25: 235, 1918.
  8. Yeoman PM, Seddon, HJ: Brachial plexus injuries: Treatment of the flail arm. J Bone Joint Surg (Br) 43: 493-500,1961.
  9. Seddon HJ: The use of autogenous grafts for the repair of large gaps in peripheral nerves. Br J Surg 35: 151-167, 1947.
  10. Oberlin C, Béal D, Leechavengvongs S, Salon A, Dauge MC, Sarcy JJ. Nerve transfer to biceps muscle using a part of ulnar nerve for C5-C6 avulsion of the brachial plexus: anatomical study and report of four cases. J Hand Surg Am. 1994;19(2):232-7.
  11. Merrell GA, Barrie KA, Katz DL, Wolfe SW. Results of nerve transfer techniques for restoration of shoulder and elbow function in the context of a meta-analysis of the English literature. J Hand Surg Am. 2001;26(2):303-14.

7 thoughts on “Brachial Plexus Injuries in Adults

  1. Respected sir,
    thank you so much for the content as it as comprehensive as we should know.

    One doubt is..
    Suppose If we clinically diagnose that the root is injured is there any point in examing the distal part of the brachial plexus at examinations?

    1. You should because
      1. Brachial plexus injuries can be mixed. For example C5 and C6 may be just neuropraxia, C7 may be a middle trunk rupture, C8 and T1 may be root avulsion.
      2. Anatomic variations

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