Obstetric Brachial Plexus Injury

Definition

 

Birth injury of brachial plexus

 

Epidemiology

 

R > L 

1 / 1000 live births

1 in 10 of these develop significant impairment

Recent increase due to bigger babies / DM

 

Aetiology

 

Usually secondary to traction

 

1.  Big baby / maternal DM / > 4000 gm

2.  Breech

3.  Prolonged / difficult labour

4.  Shoulder dystocia 

- inability to deliver the shoulders after delivery of the head

- indirect traction injury on limb with excessive lateral neck flexion

5.  Forceps delivery

- direct forcep crush injury

 

Pathology

 

Spectrum of injury

- supraclavicular traction injury

- upper roots ruptured

- lower roots avulsed

 

Classification

 

Erb Palsy

Klumpke Palsy

Total Plexus

 

ERB Palsy 

 

A.  C5,6 lesion

 

Weak

- deltoid / rotator cuff

- biceps  - elbow flexion and supination

- wrist extension

 

Waiter's Tip Deformity

- shoulder adducted & internally rotation (P major / Lat dorsi)

- elbow extended

- forearm pronated

- wrist flexed 2° FCR

 

May have winging of scapula as compensation

 

Best prognosis

- 90% recover 6/12

 

B.  C5,6,7

 

Additional weakness

- triceps / loss of elbow extension

 

Prognosis

- 50% recover 6/12

 

Klumpke Palsy

 

C8,T1 lesion

- rare

- Horner's Syndrome if preganglionic

 

Weakness of

- finger flexion

- intrinsics

 

Numb forearm & hand

 

Poor prognosis

 

Total Plexus Injury

 

C5 - T1

- flaccid numb arm 

- Horner's if preganglionic

 

Worst prognosis

- 40% recover 6/12

 

NHx

 

90% recover overall

 

Biceps best indicator of recovery

- if biceps recovers in 3/12 90% will make full recovery

- also is easiest to assess in young child

- see if child will use that hand to bring something to the mouth

 

Poor prognosis 

- no recovery 3/12

- Total plexus

- Klumpke

- preganglionic (Horner's, DSN, LTN, SSN)

 

DDx

 

Pseudoparalysis

- clavicle fracture (from delivery)

- humeral fracture

 

Arthrogryposis

- nil elbow crease

- hasn't flexed in utero

 

Monoplegic CP

 

Other

- OM / Septic arthritis

- Congenital shoulder dislocation

- sprengel shoulder

- myelodysplasia

 

Management 

 

Non operative

 

Initial

 

Physiotherapy

- maintain FROM / passive ranging

- no splinting

 

3/12

- assess biceps recovery

- EMG at 3months if no recovery

 

Long term

 

Maintain shoulder ER

- prevent posterior shoulder dislocation

- reassess child in clinic every six months

 

Operative Management

 

Indications

 

No elbow flexion / biceps recovery at 3 - 6/12

- biscuit test (hold other arm, see if can eat biscuit)

- very difficult to assess shoulder or wrist extension

 

If children don't have full recovery of biceps at 3/12 will often be left with residual deficit

 

MRI

 

Valuable if see pseudomeningocoeles

- low chance of recovery of those nerve roots

 

Timing

 

6/12 to 1 year

 

Options

 

Preganglionic avulsion

- nerve transfer

 

Postganglionic

- nerve grafting

 

Preganglionic Avulsion 

 

Nerve transfer

 

A.  Accessory nerve to suprascapular 

 

B.  Intercostal nerve to MCN

 

Postganglionic injury 

 

Neuroma resection & sural nerve grafting

 

Erbs / C5/6

- resection Erb's point

- nerve grafting

 

Aims

- lateral cord / MCN 

- SS nerve

- posterior division of upper trunk to posterior cord

 

Results

 

Late Shoulder Management

 

Issue

- residual internal rotation / adduction contracture

- tight SSC / P major / T Major / short head biceps

- humeral neck retroverted

- develop dysplasia head and glenoid

- GHJ tends to dislocates posteriorly

 

Incidence

 

10%

- more common in C5/6

- due to strong P Major and LD

 

Management Summary

 

< 6/12       Observe

6/12           Nerve transfer / graft

<2  years    Release contracture Subscapularis / T major / P major

2-5 years    Lat Dorsi Transfer

>5  years    Derotation Humeral osteotomy

 

Initial

 

Monitor and maintain ER shoulder

- physio / botox

 

Investigations

 

Indication

- limited ER

- anterior shoulder crease

 

Ultrasound

- very sensitive at 6/12 age

 

Shoulder releases

 

Timing

- < 2 years

- important to do releases early 

- avoids IR contracture 

- avoids consequent need for osteotomy or reduction of dislocation

 

Release

- P major

- T major

- Subscapularis

 

Tendon Transfers

 

Timing

- 2-5 years

 

Options

 

Lat Dorsi transfer to posterolateral rotator cuff 

- act as shoulder ER 

- often combine with releases

 

Steindler's flexorplasty

 

Humeral derotation osteotomy

 

Assessment

- CT to assess bony anatomy

- may need posterior glenoid bone block

- shoulder may be dislocated

 

Timing

- > 6-8 years