4. mesoneurium
perineurium
Fascicles of nerve fibers
epineurium
endoneurium

8. 









Focal contusion (gunshot wounds)
Stretch/traction injury
Drug injection injury
Compression
Crush injuries
Avulsion
Laceration
Electrical burns
Idiopathic
Others(Viral infections, metabolic and neural
disorders)

9. 
Changes at proximal and distal site of injury

10. Seddon, Sunderland and lately by Mackinnon
 6 degrees


11.  1st
degree of injury(neuraparaxia)
› Segmental demylination
› Axons intact
› Recovery in 12 to 16 wks
 2nd
degree injury(axonotmesis)
› Axonal injury/ distal wallerian degeneration
› Regeneration at rate of 1 inch per month
› Complete slow recovery

12. 3rd degree injury
› Axonal injury & fibrosis of endoneurium
› Incomplete recovery
 4th degree injury
› Axonal injury
› Damage to endo and perineurium with dense
scarring
› Needs surgical intervention


13.  5th degree
injury(neurotmesis)
› Complete nerve division
 6th degree injury
› Variable combination of previous five
degrees of nerve injury

15. 4th degree injury
2nd
degree
injury
1st degree injury
6th degree
injury
3rd degree injury
normal

16. •History
•Examination

Motor function
› Movements, muscle atrophy

sensory function
› Tinel sign, Ten test
› Two point discrimination
› Touch, vibration

17.  Tinel
sign: › peripheral tingling or dysaesthesia'
provoked by percussion of the nerve
› Positive in axonal injuries

18. 


EMG
NCS
Intra operative nerve action potential

19. 
Microsurgical techniques
› Adequate magnification
› Microsurgical instruments & sutures

Different techniques:
› Primary nerve repair
› Nerve grafting
› Nerve transfer
› Nerve conduits
› Nerve allografts

20. 
Sharply transected nerves
› Immediate repair

Crushed, avulsed, blast injuries
› Nerve ends tacked together
› Repair delayed for 3 weeks or until wound bed permits
 Re-exploration
 Neuroma excision, nerve grafts
 Acute nerve grafting in the 1st sitting
 Bleeding control ,trimming of fascicles ,loose epineural
suturing

Closed injuries treated expectantly for 12 weeks

23. 
Primary repair
› Tension free repair
› Mobilization of nerve ends
› Discourage
 Facilitation by postural position
 Extreme range of joint movements

24.  Primary nerve
repair
› Epineural repair
› Grouped fascicular repair

25. Standard repair

26.  Restore
the continuity of fascicles
 Internal topography
 Intra-operative nerve stimulation
 Neurolysis with the eyes
 Priority to the motor recovery(radial and
peroneal nerve)

29. Tension at site of repair
 Need of postural positioning
 Alignment of sensory & motor components
 Maximize number of axons
 Reversal of graft
 Exclusion of expendable nerve


30. Sural nerve
› 30-40cm
› Lateral peroneal communicating br : 10-20cm
 Lateral antebrachial cutaneous nerve(LABC)
› 8cm
 Medial antebrachial cutaneous nerve (MABC)
› Anterior & posterior division
› 20 cm
 Expendable nerves(peroneal and radial)
 Sensory branches of ulnar and median nerves
 Distal anterior interosseous nerve and so on…


31.  Donor site
scarring
 Donor site sensory loss
› Patient education

32. Complete : resection and repair with graft

34. Incomplete neuroma
 Intra-operative nerve stimulation
 Black boxing around neuroma


36. 
Indications:
› Very proximal peripheral nerve injuries
› Root avulsions
› Excessive scarring
› Level of injury unclear
 Idiopathic neuritides
 Radiation induced nerve injury

37. 
Motor nerve transfer
› Pure motor axons
› Close proximity
› expendable
› Synergistic supply

Sensory nerve transfer
› pure sensory axons
› Innervates non critical area
› Expendable and lying in close proximity

38. elbow flexion
 Shoulder abduction
 Ulnar-innervated intrinsic hand function
 Forearm pronation
 Radial nerve function


39. Transfer of radial nerve to axillary nerve

40.  Veins,
pseudo-sheaths, bioabsorbable tubes
 short nerve gaps ≤ 3cm
 Low antigenicity , biodegradability
 Trials to add a nerve graft inside the conduit
› neurotrophic factors

42. Extensive injuries
 Limited donor material
 Immunosuppressive agents

› FK506( tacrolimus )
› Prednisone , azathioprine

Processed acellular cadaveric nerve allografts
› AxoGen, Inc. ,Alachua, FL.