October 5, 2019 at 7:15 am #96400Dominic PowerKeymaster
The spinal accessory nerve to suprascapular nerve transfer is the mainstay of reconstruction of function in the C5 nerve root avulsion brachial plexus injury. Combined with a triceps branch transfer to the axillary nerve reliable shoulder abduction is restored. External rotation is often more limited and may be due to the fact that the infraspinatus reinnervation is not always complete.
My experience of the transfer is that some anterior approach cases do not get reliable innervation of the supraspinatus or infraspinatus and this may because of unrecognised injury to the suprasapular nerve at the scapular notch beneath the supra scapular ligament. In a high energy traction injury across the brachial plexus this is a point of tether and the nerve may rupture or form a neuroma in continuity.
I prefer therefore the posterior approach that visualises the supra scapular nerve at the notch and performs a more distal transfer using the medial branch of the spinal accessory nerve. My results demonstrate 30% concomitant injury rate at the notch and the results this distal posterior transfer are good.
I am concerned however that external rotation remains poor in some cases and this may be due to concomitant injury to the infraspinatus branch of the suprascapular nerve at the spine gelenoid notch where it courses around the base of the scapular spine. Injuries here cannot easily be seen.
When I performed the triceps to axillary transfer at the same time, it is possible to use the medial triceps motor branch that is longer than the long head branch popularised by Somsak Leechavengvongs. The transfer can be directed to both anterior and posterior divisions of the axillary nerve to allow reinnervation of both deltoid and teres minor. The Teres minor is an external rotator and as such improves the overall function of the shoulder even when the infraspinatus does not recover well.
Additional procedures to directly reinnervate the infraspinatus can be performed using direct intramuscular neurotisation techniques or a novel technique targeting the infraspinatus branch of the suprascaular nerve at the spinoglenoid notch. The exposure is challenging and opens the interval between the spina of the scapular and the upper border of infraspinatus.
The triceps to axillary transfer can be used to reinnervate all of the axillary nerve and then the upper lateral cutaneous nerve of the forearm can be detached from the skin and used as a reversed vascularise pedicled sensory autologous graft to direct axons to a co-aptation with the infraspinatus branch of the supra scapular nerve or direct intramuscular neurotisation.
Combining these transfers ensures reliable restoration of two abductors and two external rotators to improve shoulder function.
How do you do these procedures? Do you prefer a double transfer for C5 root avulsion injury of the brachial plexus?
- This topic was modified 10 months, 2 weeks ago by Dominic Power.
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