2. Anatomy of radial nerve
Continuation of posterior cord of brachial plexus(C5-T1)
In the axilla, gives off a branch to the long head of triceps and
enters the arm.
3.
4.
5. Course of radial nerve
IN THE AXILLA
Radial nerve lies anterior to subscapularis , teres major ,
lattismus dorsi.
Sensory supply : posterior cutaneous nerve of arm
Radial nerve leaves axilla via triangular space
Motor supply : long head of triceps
Radial nerve comes to lie along spiral groove on posterior aspect
of humeral shaft along with profunda brachii artery
Motor supply : medial and lateral head of triceps , anconeus
Sensory supply : posterior cutaneous nerve of forearm, lower
cutaneous nerve of the arm
6. • Radial nerve then leaves the spiral groove by piercing the
lateral intermuscular septum to enter anterior compartment of
arm, 10-12 cm above the lateral epicondyle (lies b/w brachialis
and brachioradialis)
• Motor supply : brachialis (lateral part), BR, ECRL
• Anterior to lateral epicondyle: Radial nerve divides into 2
branches:
1. Posterior Interosseous nerve (PIN)
2. Superficial radial sensory nerve
7. Posterior interosseus nerve
• Gain access to posterior forearm by dividing posterior and
laterally through ligament of frohse and the interval b/w the
two heads of supinator.
• Arcade of frohse is a fibrous arch originating lateral
epicondyle superior part of superficial layer of supinator.
• Supply to all extensor compartment muscle.
8. • Superficial radial nerve courses through the forearm
immediately deep to the BR
• It emerges b/w tendon of BR and ECRL proximal to radial
styloid
• Passes over tendons of snuffbox
• Terminates as cutaneous branches to dorsum of hand and
lateral 3.5 digits short of nailbeds.
9.
10.
11. Types
1. Very high radial nerve palsy
2. High radial nerve palsy
3. Low radial nerve palsy
12. Very high radial nerve palsy
Level of injury : at the axilla
Causes : crutch palsy (chronic compression in the axilla)
Trauma or operation around the shoulder
Aneurysms of axillary vessels
Clinical features
Motor deficit : loss of extension of forearm
weakness of supination
Loss of extension of hand and finger
Sensory deficit: lateral arm
Posterior forearm
Radial half of dorsum of hand
Dorsal aspect of radial three and half digits (excluding
their nail beds)
13. High radial nerve palsy
Level of injury: in the radial groove
Causes : Fracture shaft of humerus
Prolonged application of tourniquet
Clinical features
Motor deficit : Weakness of supination
Loss of extension of hand and fingers
Sensory deficit : Posterior forearm
Radial half of dorsum of hand
Dorsal aspect of radial three and half digits
(excluding their nail bed )
14. Low radial nerve palsy
Level of injury : below the elbow
Causes : dislocation of elbow
Fracture neck of radius
Clinical features
Motor deficit : Extension of hand
Extension of finger
Sensory deficit : None
15. Examinations
(a) Is there any an obvious wrist drop
(b) Is there wasting of the forearm muscles
(c) Is there wasting of the triceps
21. Other tests
1. Nerve conduction study
2. Electromyography
3. Tinel sign
4. Sweat test
5. Skin resistance test
22. Principles of Treatment
A. Nerve Exploration
Indications
a) if the nerve was seen to be divided and needs to be
repaired
b) if the type of injury suggests that the nerve has been
divided or severely damaged
c) if the recovery is inappropriately delayed and the
diagnosis is in doubt
23. B. Primary repair
Primary suture at the time of wound toilet has considerable
advantage
There should be no tension on the suture line.
C. Delayed repair
Indications
a) a closed injury was left alone but shows no sign of recovery
at the expected time
b) the diagnosis was missed and the patient presents late
c) primary repair has failed
24. D. Nerve grafting
Sural nerve is the most commonly used
Up to 40cm can be obtained from each leg
The graft should be long enough to lie without any tension and
it should be routed through a well vascularized bed
The graft is attached at each end either by fine sutures or with
fibrin glue
25. E. Nerve transfer
The principle of nerve transfer is that a less essential function is
sacrificed to reinstate a more vital one
Indication :
a) very proximal nerve injury such as root avulsion
b) the distance to the target organ or length of graft required precludes
any chance of recovery
F. Tendon transfer
Is consider if axon regeneration at about 1mm per day do not reaches
the muscle within 18-24 months of injury
26. Prognosis
1. Delay to repair : best outcomes with immediate repair
2.Age of patent: children do better than adults
3.Nature of nerve injury :clean cut > crush > traction
4.Length of injured segment :graft of 10cm is unlikely to work
5.Distal > proximal level of lesion : higher the lesion the worst
the prognosis
6. Associated vascular injury : both nerve and its target organ
requires adequate blood supply
27. 7. Associated direct muscle damage :prevent good muscle re-
innervation and in some circumstances (eg hamstring injury in
sciatic nerve lesion) make nerve repair technically difficult
8. Type of nerve : pure motor or pure sensory recover better than
mixed because there is less likelihood of axonal confusion
9.Surgical techniques