Brachial plexus injury (BPI) is a devastating injury that could result in permanent loss of function and chronic pain in the upper limb. Motorcycle accident is the leading cause of adult traumatic BPI which typically occurs in young males. For practical purposes, the injuries may be divided into:
- Supraclavicular BPI
There are two basic clinical presentations:
- Partial palsy involving the upper roots (C5,6 or C5,6,7)
- Total palsy (C5-T1)
- Infraclavicular BPI
These injuries typically occur secondary to shoulder trauma.
Narakas, a pioneer in brachial plexus surgery, outlined the Rules of Seven 70's:
- 70% of brachial plexus injuries are due to road traffic accidents
- 70% of these involved motorbikes
- 70% have multiple injuries
- 70% are supraclavicular injuries
- 70% of these have at least 1 root avulsion
- 70% of root avulsion involve the lower plexus
- 70% of root avulsions will leave the patient with chronic pain
Mechanisms of Injuries
- Road traffic accident
- Birth trauma (risk factors include shoulder dystonia, large infants, maternal obesity, diabetes, cephalopelvic disproportion and forceps delivery)
- Shoulder girdle trauma (dislocation, proximal humeral fractures, hyperextension injury)
- Gunshots injuries
- Iatrogenous (e.g. clavicle plating)
Imaging modalities including plain radiographs, CT myelography (invasive) or MRI (noninvasive) are utilised to provide supplementary information to aid decision making.
Neurophysiology is another important adjunct to the the overall diagnostic (and prognostic) process. It is generally performed at least 3 weeks after the injury as earlier studies may be misleading.
Treatment of BPI involves complex decision making which can only be made after careful and thorough assessment by your surgeon. There are however three key considerations:
1. Who requires surgery?
- Those who have no hope of spontaneous recovery – such as root avulsions.
- Those in whom there is no clinical and/or neurophysiological evidence of improvement after serial examinations.
2. When should you proceed to surgery?
- Following nerve avulsion/rupture, apart from end-organ degeneration (motor end-plate), there is also central neuronal death by apoptosis (‘A race against time’).
- Early exploration is thus favoured for diagnostic and prognostic purposes.
3. What are the surgical priorities (this has to be individualised)?
- Restore elbow flexion
- Restore shoulder abduction (stability)
- Restore hand function
In early reconstructions, primary nerve surgery (neurolysis, nerve grafting and nerve transfer) is favoured. In delayed presentations (>1 year) or when the outcome of nerve surgery is likely to be poor, reconstructive options include fusion, tendon transfers and free functioning muscle transfer.
Following brachial plexus surgery, patients will require prolonged rehabilitation by specialist physiotherapist and occupational therapist. Pain control can be challenging and often requires the input of a pain specialist.