nerve injuries is an essential learning exercises

1. Nerve Injuries
Prof G S Patnaik

2. Axillary Nerve

4. Median nerve: Anatomy
• Formed by
o C5 to C7 roots from lateral cord of brachial plexus
o C8 and T1 roots from medial cord
• Branches
o Forearm: Muscular branches
o Pronator teres
o Flexor carpi radialis
o Flexor carpi sublimis

5. Median nerve: Lesions
GOWERS SIGN
• Normal hand
Thumb is
perpendicular to
plane of palm
• Median nerve lesions
Thumb is externally rotated
into plane of palm.
Thenar eminence is wasted.

6. Median nerve: Lesions
•Axilla
oCrutch compression
oMissile injury
oAnterior shoulder dislocation
•Upper arm
oStab wounds: ± brachial artery injury
oSleep palsy: Near pectoralis major tendon
o Tourniquets
oFracture: Humerus shaft

7. Median Nerve Lesions
• Elbow
o Supracondylar spurs & ligaments (Struthers)
o Fracture
o Humerus supracondylar: Children; Anterior interosseous distribution
o Medial epicondylar #
o Elbow dislocation
o Injection injury
o Pronator teres syndrome
o Pain in volar forearm exacerbated by repeated
pronation
• Little weakness or sensory loss

8. Median Nerve Injuries
• Anterior interosseus: Syndrome
o Fracture: Radius midshaft
o Excessive exercise
o Idiopathic
o Stab wound
o Anomalies: Muscle; Fibrous bands in
Course of nerve deep to pronator teres
o Weakness also seen with
o Brachial neuritis
o Supracondylar fractures
o Proximal neuroma or other median nerve lesions
• Tendon rupture: FPL & FDP in rheumatoid arthritis

9. Median Nerve Injuries
• Median neuropathy in forearm
o Bleeding into flexor compartment
o Hemophiliacs; Anticoagulants; Brachial artery puncture
o A-V fistula for dialysis: Pain common; Onset days to
weeks after surgery
o Carpal tunnel syndrome

10. MEDIAN NERVE LESIONS
o Anterior interosseus (motor): Anatomy & Exam
o Flexor pollicis longus
o Flexor digitorum profundus to 2nd & 3rd fingers
o Pronator quadratus

11. Radial Nerve
Anatomy
•Formed by: Axons from C5 to T1 roots
•Axons pass through
oSpiral groove of humerus
oFibrous arch attachment of triceps to
humerus
oLateral intermuscular septum below
deltoid insertion
oArcade of Frohse: Above supinator &
Below elbow

12. Radial Nerve Lesions

13. Radial Nerve
•Branches
oAbove elbow
oAbove spiral groove (Humerus)
oTriceps: 3 to 5 branches
oAnconeus
oBelow spiral groove
oBrachioradialis: Distal to
lateral intermuscular septum
oExtensor carpi radialis longus
& brevis
oPosterior cutaneous nerves of
arm & forearm Supply lateral &
dorsolateral arm & fore

14. Radial Nerve Branches
o At or below elbow
o Above arcade of Frohse (Supinator)
o Superficial radial nerve: Sensory dorsolateral hand & 1st 3 digits
o Posterior interosseus nerve: Extensor carpi radialis brevis & Supinator
o Passes through arcade of Frohse
o Posterior interosseus nerve: Terminal motor branch
o Passes through the supinator muscle
o Innervates
o Finger & thumb extensors
o Extensor carpi ulnaris
o Abductor pollicis longus
o Articular branches to wrist joint

15. Radial Nerve Lesions
•Radial nerve compression or injury may
occur at any point along the anatomical
course of the nerve and may have varied
etiologies.
• The most frequent site of compression is
in the proximal forearm in the area of the
supinator muscle and involves the
posterior interosseous branch.
•It can occur proximally in relation to
fractures of the humerus at the junction of
the middle and proximal thirds, as well as
distally on the radial aspect of the wrist.

16. Radial Nerve Lesions
• Radial nerve palsy in the middle third of the arm is
characterized by palsy or paralysis of all extensors of the
wrist and digits, as well as the forearm supinators.
• Very proximal lesions also may affect the triceps.
Numbness occurs on the dorsoradial aspect of the hand and
the dorsal aspect of the radial 3 1/2 digits.
• Sensation over the distal and lateral forearm is supplied by
the lateral antebrachial cutaneous nerve and therefore is
preserved.

17. During World War I, Sir Robert
Jones developed a set of tendon
transfers for radial nerve paralysis,
which formed the basis for
reconstructive tendon transfer
surgery. The transfer included PT to
ECRL and ECRB; FCU to EDC III-
V; and FCR to EIP, EDC III, and
EPL. Many modifications have
been made to this plan, primarily
maintaining a wrist flexor.

18. Ulnar Nerve
•Formed by: C8 and T1 ± C7 roots
•Axons pass through
oLower trunk & medial cord of
brachial plexus
o Ulnar groove @ elbow
o Cubital tunnel under flexor carpi
ulnaris Guyon's canal: Between
pisiform & hamate bones in hand

19. Ulnar Nerve
•Branches: All distal to elbow
o Forearm
oFlexor carpi ulnaris (FDU)
oFlexor digitorum profundus
(FCP)(4th & 5th fingers)
oPalmar cutaneous sensory to
proximal ulnar palm
oDorsal ulnar cutaneous to 5th &
ulnar side of 4th finger
o Hand: All motor
oPalmaris brevis
oInterossei
oLumbricals (3rd & 4th)
oFlexor pollicis brevis

20. Ulnar Nerve Lesions
•Presenting symptoms can vary
from mild transient paraesthesias
in the ring and small fingers to
clawing of these digits and severe
intrinsic muscle atrophy
• Patients may report difficulty in
opening jars or turning doorknobs.
Early fatigue or weakness may be
noticed if work requires repetitive
hand motions

21. Ulnar Nerve Lesions
•Presenting symptoms can vary
from mild transient paraesthesias
in the ring and small fingers to
clawing of these digits and severe
intrinsic muscle atrophy
• Patients may report difficulty in
opening jars or turning doorknobs.
Early fatigue or weakness may be
noticed if work requires repetitive
hand motions

22. Ulnar Nerve Lesions
• Numbness usually precedes motor loss. Muscle wasting
and clawing of the ring and small digits are indicative of a
chronic compressive syndrome.

23. Ulnar Nerve Lesions
• Pressure or injury to the ulnar nerve along its
anatomic course may cause denervation and
paralysis of the muscles supplied by that nerve.
• One of the most severe consequences is loss of
intrinsic muscle function in the hand.
• When the ulnar nerve is divided at the wrist, only
the opponens pollicis, superficial head of the
flexor pollicis brevis, and lateral 2 lumbricals are
functioning

24. Post.Interroseous Synbdrome
• Patients with posterior interosseous nerve
syndrome present with weakness or paralysis of
the wrist and digital extensors.
• Pain may be present, but it usually is not a primary
symptom. Attempts at active wrist extension often
result in weak dorsoradial deviation due to
preservation of the radial wrist extensors but
involvement of the extensor carpi ulnaris and
extensor digitorum communis.
• These patients do not have a sensory deficit.

25. Radial Nerve Injuries
• closed fracture of the humerus in satisfactory alignment with
radial nerve palsy is not an indication for immediate exploration.
• A 6- to 12-week waiting period is indicated, and if no return of
function occurs, exploration of the nerve is indicated.
• In the case of open humeral fracture with radial nerve palsy,
because debridement of the wound with probable internal
fixation will be performed, exploration of the nerve and repair if
necessary are indicated.
• Nerve injuries in continuity to an open fracture are gently
explored and followed for 6-12 weeks before any further
treatment is initiated.

26. Foot Drop
• Foot drop is a deceptively simple name for a
potentially complex problem.
• Foot drop can be associated with a variety of
conditions such as dorsiflexor injuries, peripheral
nerve injuries, stroke, neuropathies, drug toxicities, or
diabetes.
• The causes of foot drop may be divided into 3
general categories: (1) neurologic, (2) muscular, and
(3) anatomic. These causes may overlap.
• Treatment is variable and is directed at the specific
cause.

27. Foot Drop
•Foot drop can be defined as a significant
weakness of ankle and toe dorsiflexion.
• The foot and ankle dorsiflexors include
the tibialis anterior, extensor hallucis
longus, and extensor digitorum longus.
•These muscles help the body clear the foot
during swing phase and control plantar
flexion of the foot on heel strike.
•Weakness in this group of muscles results
in an equinovarus deformity

28. Treatment of foot drop
• Directed to its etiology.
• If foot drop is not amenable to surgery, an ankle foot
orthosis (AFO) often is used. An AFO also is used during
surgical or neurological recovery. The specific purpose of
an AFO is to provide toe dorsiflexion during the swing
phase, medial and/or lateral stability at the ankle during
stance, and if necessary, push-off stimulation during the
late stance phase. An AFO is helpful only if the foot can
achieve plantigrade position when standing. Any equinus
contracture prohibits its successful use

29. Surgical Treatment: Foot Drop
• Nerve exploration, decompression, or
repair.
• Tendon transfer
• After a tendon transfer procedure, the patient
is placed in a cast and restricted to non–
weight-bearing ambulation for 6 weeks. This
period is then followed by physical therapy for
gait training