diagnosis and principles of management of peripheral nerve injuries

1. Diagnosis and principles of
management of radial, ulnar,
median and sciatic nerve.
Presentor: Arpan Katwal (1742)

2. Frequency of specific nerve involvement:

3. Radial nerve
• Most commonly injured nerve
• Best prognosis
• Supplies triceps, supinators of forearm and extensors of wrist, thumb
and fingers.

5. Sensory supply of radial nerve

6. Type of lesion Cause Manifestations
Very high Saturday night palsy
Crutch palsy
Surgical procedures or trauma
around shoulders
Loss of function of triceps,
wrist drop, thumb drop, finger
drop
High Fracture of shaft of humerus Triceps spared, wrist drop,
thumb drop, finger drop
Low Injury at around lateral condyle
of humerus.
Wrist extensors spared
Thumb drop, finger drop

8. Tests:
• Wrist drop test

9. Median Nerve
• Aka laborer’s nerve
• Supplies all anterior compartment muscles of forearm except FCU and
medial half of FDF.
• In hand all thenar muscles except adductor pollicis.
• Anterior interosseous nerve: supplies FPL and lateral half of FDF

10. Sensory supply:

11. High median nerve injury low median nerve injury
Injury at and proximal to elbow Injury in distal third of forearm
Paralysis of all the muscles supplied by
median nerve in forearm and hand
Sparing of forearm muscles but muscles
of hand will be paralyzed.
In addition to the lower nerve lesion, the
long flexors of thumb, index and middle
finger, radial wrist flexors and the
forearm pronators are paralyzed
Patient unable to abduct the thumb and
sensation is lost over the radial three and
half digits

12. Test/Sign Muscle
Ape thumb Thenar muscle wasting

13. Test/Sign Muscle
Kiloh nevins sign Flexor digitorum profundus + flexor pollicis longus

14. Test/Sign Muscle
Pointer index, Benediction
sign/ Ochsner’s clasp sign
Flexor digitorum superficialis+ lateral half of flexor
digitorum profundus

15. Test/Sign Muscle
Pen test Abductor pollicis brevis

16. Ulnar nerve
• Aka Musician’s nerve
• Supply FCU and medial half of FDP in forearm
• All hypothenar muscles and adductor pollicis, lumbricles 3,4 and
palmar and dorsal interossei.

17. Sensory supply:

18. High ulnar nerve palsy Low ulnar nerve palsy
Injury proximal to the elbow Injury in distal third of forearm
Muscles of forearm involved Muscles of forearm spared
Sensory loss over palmar and dorsal
aspect of medial third of hand.
Sensory loss over palmar and dorsal
aspect of whole of little finger and ulnar
half of ring finger.
No sensory loss over proximal and middle
phalanx of little finger due to sapring of
dorsal cutaneous branch.

19. Tests
• Froment’s sign- Adductor pollicis
• Card test- palmar interossei
• Egawa test- dorsal interossei

20. Froment’s sign

21. Card test

22. Egawa test
• With palm flat on the table, the patient is asked to move the middle
finger sideways.

23. Sciatic nerve
• Composed of fibers from L4, L5, S1, S2 and S3.
• Peripheral component is common peroneal nerve and deep
component is tibial nerve.
• Injury to sciatic nerve usually affects the superficial part of the nerve.
Hence the symptoms of common peroneal nerve palsy predominates.

24. Effects of sciatic nerve injury:
• Motor effects:
• Marked wasting of muscles below the
knee
• Weak flexon of knee
• Weak extension of hip.
• All the muscles below the knee are
paralyzed and the weight of the foot
causes it to assume the plantar flexed
position, or foot drop.

25. Effects of sciatic nerve injury:
• Sensory effect:
• Sensation is lost below the
knee, except for a narrow
area down the medial side
of the lower part of leg
(blue) and along the medial
border of the big toe ,
which is supplied by the
saphenous nerve.

26. Diagnostic tests of nerve injury
• Electromyography
• Nerve conduction velocity

27. Electromyography
• Involves recording of electric potentials
from needle electrode in muscle both
at rest and during voluntary
contraction
• Resulting electromyographic patterns
displayed on an oscilloscope
• Most useful for distinguishing between
and among myopathic and
neuropathic disorders.

28. Nerve Conduction Velocity
• Stimulation – stimulated electrically by an electrode placed on the
skin overlying the nerve-evokes a response from the muscle
innervated, AP propagates to innervate the muscle.
• Response – be seen, measured and palpated.
• Nerve - stimulated proximal to, distal to, and across the level of injury.
• Latency, amplitude of CMAP, NCV can be calculated

29. Principles of management

30. General considerations:
• In clean cut wounds, nerve repair done till 7 days
• In contaminated wounds , do loose end to end apposition or
suture to soft tissues
• Early active motion of all joints of involved extremity should be
started
• Gentle passive exercises
• Joints should be kept supple and soft tissue contractures
prevented
• Dynamic and static splinting

31. Surgical considerations:
Nerve Exploration
• Indications :
• Sharp injury has obviously divided a nerve
• Abrading, avulsing or blasting wounds
• Nerve deficit follows blunt or closed trauma with no clinical
or electrical evidence of regeneration
• Nerve deficit follows a penetrating injury with no evidence of
regeneration
• Timing :
• Primary repair done in 1st 6-8 hrs
• Delayed primary repair in first 7 -18 days in sharp cut wounds

32. Primary vs Delayed repair
Primary Repair Delayed repair
Indications Injury caused by sharp object, clean
wound, no major complicating injuries
Missed diagnosis, closed injury left
expectantly without signs of recovery, failed
primary repair
Advantages Nerve ends not retracted much,
rotational alignment relatively
undisturbed, no fibrosis
Infection is less, nerve graft or transfer or
tendon transfer can be planned

33. Types of nerve repair:
• Neurolysis
• Neurorrhaphy
• Nerve grafting
• Nerve Transfer
• Tedon grafting

34. Critical limit of delay
Nerve Critical limit of delay
Radial 15 months
PIN 9 months
Ulnar 9 mo ( high lesion), 15 months ( low lesion)
Median 9 mo ( high lesion), 12 mo ( low lesion)
Sciatic 12-15 months
CPN 12 months

35. Factors affecting outcome after repair:
• Age of patient
• Time between injury and repair
• Nature of nerve injury:Clean cut> Crush> Traction
• Level of injury: The higher the lesion,the worse the prognosis
• Associated vascular injury
• Length of injured segment: graft of >10 cm is unlikely to work
• Tpye of nerve
• Surgical skills

36. References
• Campbell’s Operative Orthopaedics
• Apley’s System of Orthopaedics and Fractures

37. Thank you