anatomy & injury of nerve

1. Common peroneal
neuropathy
P/B :- DR NIYATI PATEL 1

2. ANATOMY
 Common peroneal nerve is also known as lateral popliteal
nerve
 Root value – L4,L5,S1,S2
 The common peroneal nerve is the smaller and terminal
branch of the sciatic nerve which is composed of the
posterior divisions of Lumbosacral plexus.
 MOTOR SUPPLY
 DEEP PERONEAL NERVE
 Tibialis anterior
 Extensor halluces longus
 Extensor digitorum
 Extensor digitorum brevis
 Peroneus tertius
 SUPERFICIAL PERONEAL NERVE
 Peroneus longus
 Peroneus brevis
Sensory
supply
P/B :- DR NIYATI PATEL 2

3. CAUSES
 Compression of the nerve by tight plaster or a splint
 Fracture of the neck of the fibula
 Fracture dislocation of the head of fibula
 Hansen’s disease or leprosy
 Trauma to the knee including rupture of the fibular
collateral ligament
 Entrapped, compressed or irritated nerve by fibrous
arch as it winds around the neck of fibula
 Prolonged immobilization during which the leg lies in
external rotation.
P/B :- DR NIYATI PATEL 3

4. SIGN & SYMPTOMS
 Sensory
 Common peroneal nerve by itself is relatively short having only two
sensory branches and no motor branches. The loss of sensation is as
follows:
 a. Skin along the lateral aspect of the knee in the proximal third of the
calf (lateral cutaneous sural nerve).
 b. Skin over the posterolateral aspect of the calf and over the lateral
malleolus, lateral aspect of the foot and fourth and fifth toes (Sural
nerve).
 Common peroneal nerve divides into deep and superficial peroneal
nerve.
 Deep peroneal nerve palsy leads to loss of sensation over the
following areas:
 a. Web space between the great and the second toe.
 b. Lateral aspect of the dorsum of the great toe.
 c. Medial aspect of the dorsum of the second toe.
 Superficial peroneal nerve palsy leads to loss of sensation over the
following areas:
 a. Anterior and lateral aspect of the leg
 b. Dorsum of the foot and toes except a small wedge shape area in the
web space between the great and the second toe.
P/B :- DR NIYATI PATEL 4

5.  Motor
 Deep peroneal nerve palsy leads to paralysis of
tibialis anterior, extensor hallucis longus,
extensor digitorum longus, extensor digitorum
brevis and peroneus tertius.
 Superficial peroneal palsy leads to paralysis of
the peroneus longus and peroneus brevis
 Reflex
 Ankle jerks  diminishes
P/B :- DR NIYATI PATEL 5

6.  Deformity
 Equino varus deformity (Foot drop) results due
to over action of the posterior compartment
muscles and the invertors.
 Gait
 High Steppage gait / foot drop gait
 Muscle wasting
 Present over dorsiflexors of leg
 ROM
 AROM Loss of dorsiflexion, eversion, extension
of toes
P/B :- DR NIYATI PATEL 6

7. FUNCTIONAL DISABILITY
 Pt is dependent for functional activities
such as walking, squatting, dressing,
transfers, toilet activities
P/B :- DR NIYATI PATEL 7

8. INVESTIGATIONS
 RADIOGRAPH :- shows whether there is presence of fracture
 MRI :- To delineate complete avulsion of nerve roots
 SD CURVE:- abnormality in conduction can be verified.
Sharp curve, long chronaxie, low rheobase and the absence
of contraction with repetitive stimuli indicates
denervation. If it is done 2-3 weeks after injury, it shows
the sign of denervation and to find out whether it is
moderate or severe injury
 NCV:- To find out the severance of nerve fibers with
wallerian degeneration.
 EMG:- it will help to find out reversible and irreversible
nerve damage and will help map out whether it pre
ganglionic/ post ganglionic lesion
P/B :- DR NIYATI PATEL 8

9. TYPES OF INJURY
 In Neuropraxia  pain, numbness, muscle weakness,
minimal muscle wasting is present. Recovery occurs
within minutes to days
 In Axonotmesis  there is pain, evident muscle wasting,
complete loss of motor, sensory and sympathetic
functions. Recovery time– months (axon regeneration at
1-1.5 mm/day)
 In Neurotmesis  no pain, complete loss of motor,
sensory and sympathetic functions. Recovery time –
months and only with surgery
P/B :- DR NIYATI PATEL 9

10. SPECIAL TEST
 Tinnel’s sign - Tinel's sign is a reliable clinical sign to
localise area of nerve irritation or entrapment - Tapping
along the course of the nerve (particularly around the
fibular neck) causing shooting pain and tingling into the
foot
 SLR test
P/B :- DR NIYATI PATEL 10

11. SURGICAL MANAGEMENT
 tendon transfer wherein the Tibialis posterior is used to
substitute for the lost muscles.
 The tibialis posterior transfer may be done in two ways:
 • Circumtibial route: The tibialis posterior is detached
from its insertion circles around tibia and is divided into
two clips—onegoing to tibialis anterior and extensor
hallucies longus whereas the other go to extensor
digitorum longus. This procedure is more commonly
done but adhesions are likely to occur which are treated
with US, laser and kneading technique
 Interosseous route: Insertions are the same as above but
the transfer is done by piercing the interosseus
membrance.
P/B :- DR NIYATI PATEL 11

12. P/B :- DR NIYATI PATEL 12

13. PREVENTION
 • Total period of immobilization is six weeks. For the
first three weeks the knee is in flexion and the ankle is
in full dorsiflexion.
 In the next three weeks the knee is kept free but the
ankle is still maintained in full dorsiflexion. This method
gives a better range of dorsiflexion.
 • The ankle is immobilized in full dorsiflexion for a
period of six weeks.
P/B :- DR NIYATI PATEL 13

14. PHYSIOTHERAPY
MANAGEMENT
 Conservative treatment consists of the
following:
 IG stimulation of the paralyzed muscles
 Passive movements to maintain the joint
range
 Stretching of the Tendoachilles
 Non Weight bearing and weight bearing
exe
 Splints or Orthosis: The commonly used
orthosis aims to maintain the ankle in
neutral position preventing equinous
hence either a caliper with dorsiflexion
stop or plastic ankle foot orthosis in the
form of shoe insert may be prescribed.
P/B :- DR NIYATI PATEL 14