This document provides information on radial, median, and ulnar nerve injuries, including anatomy, causes, examination findings, and treatment options. It describes the anatomy and branches of each nerve. Common causes of injury include lacerations, fractures, and entrapment syndromes. Examination involves testing specific muscles innervated by each nerve. Surgical treatment may include nerve repair or reconstruction using tendon transfers to restore function when nerve recovery is not possible. The document outlines various tendon transfer procedures used to treat different patterns of nerve injury.

1. MAJ VIVEK MATHEW
RESIDENT
DEPT OF ORTHOPAEDICS

2. Nerve injuries
 Anatomy
 Causes
 Patterns of injury
 Examination
 Principles of Surgery
 Reconstructive surgery

4. ANATOMY
 Continuation of posterior cord of brachial plexus
 C5,C6, C7, C8,(T1)
 Primarily motor nerve
 Innervates
 Triceps
 Supinators of the forearm
 Extensors of the wrist, fingers, and thumb.

5. • Formed in front of
subscapularis;pass
anterior to lat dorsi to pass
through the triangular
interval
• accompanied by the
profunda brachii artery

6. upper arm
• enters posterior (extensor)
compartment
• supplies triceps
• re-enters anterior compartment of
arm by piercing lateral
intermuscular septum.

7. • At the level of the lateral
epicondyle
• gives off posterior interosseous
nerve
• passes between two heads of
supinator
• enters the extensor
compartment of the forearm.

8. • The superficial radial nerve
continues into the forearm in
the anterior compartment deep
to brachioradialis
• terminates by supplying the
skin over the posterior
aspect of the thumb, index,
middle and radial half of
the ring finger

9. Causes:Radial Nerve injury
 Fractures of humeral shaft
 Gunshot wounds, lacerations of arm and proximal forearm
 Injection injuries
 Entrapment syndromes
 in the arm : fibrous arch of the lateral head of the triceps muscle.

11. PIN ENTRAPMENT SYNDROME
 Two types of posterior interosseous nerve entrapment
(Spinner).
 Type I
 Complete paralysis of all muscles supplied by the nerve
 include
 extensor digitorum communis,
 extensor indicis proprius,
 extensor digiti quinti,
 extensor carpi ulnaris,
 abductor pollicis longus,
 extensor pollicis brevis.
 Type II
 only one or a few of these muscles are paralyzed.

12. PIN ENTRAPMENT SYNDROME
 . posterior interosseous nerve :
 fracture-dislocations or dislocations of the elbow,
 fractures of the forearm,
 Volkmann ischemic contracture, ,
 aneurysms,
 rheumatoid synovitis of elbow

13. Radial Tunnel Syndrome
 Entrapment of the posterior interosseous nerve leading to
chronic and refractory tennis elbow (Roles and Maudsley).
 Four potentially compressive anatomical structures:
 (1) the origin of the extensor carpi radialis brevis,
 (2) adhesions around the radial head,
 (3) the radial recurrent arterial fan, and
 (4) the arcade of Frohse as the posterior interosseous nerve enters
the supinator.
 Presentation:
 Pain in the region of the radial nerve beneath the extensor mass at
and just distal to the radial head,
 pain on resistance to supination of the forearm,
 electrodiagnostic measures

14. Superficial Radial Nerve palsy
 Etiology:
 nerve may be caught in scar tissue at the wrist after
surgery or trauma.
 Constricting jewelry
 Presentation:
 pain in forearm
 sensory impairment on the dorsum of the thumb.

15. Examination
 Following muscles can be tested accurately because
their bellies or tendons can be palpated:
 triceps brachii,
 brachioradialis,
 extensor carpi radialis,
 extensor digitorum communis,
 extensor carpi ulnaris,
 abductor pollicis longus,
 extensor pollicis longus.

16. Diagnosis
 Inability to
 extend the elbow
 supinate the forearm
 wristdrop.
 An inexperienced examiner often may be misled by
the patient's ability to extend the wrist merely by
flexing the fingers.

17. Examination
 by injuries of the nerve at the level of the middle of the
humerus or distally.
 triceps not seriously affected
 In injuries of the nerve at its bifurcation into the deep
and superficial branches,
 the brachioradialis and the extensor carpi radialis longus
continue to function;
 the arm can be supinated, and the
 wrist can be extended.
 The nerve is especially susceptible to electrical
stimulation in situ just proximal to the elbow

18.  Sensory examination
 no autonomous zone.
 If present : over the first dorsal interosseous muscle,
between the first and second metacarpals.
 too inconsistent
 confirmatory evidence of complete interruption of the
nerve proximal to its bifurcation at the elbow.

19. HIGH V/S LOW LESIONS

20. Treatment
 Methods of Closing Gaps
 Interfascicular nerve grafting:preferred method
 Mobilization techniques
 In axilla & proximal arm on medial side proximal to the
point of emergence of branches to triceps,
 6 to 7 cm
 without sacrificing the branches to the triceps
 Resecting humerus not feasible at this level.

21. Treatment
 Methods of Closing Gaps
 In middle third of arm,
 10 to 12 cm
 mobilizing the nerve from the elbow to the clavicle
 widely stripping the branches of the nerve, by
 Flexing & externally rotating shoulder, adducting arm across
the chest,
 sacrificing branch to brachioradialis (if biceps is functioning).
 Transposing the nerve beneath the biceps anterior to the
humerus,
 3 to 4 cm of humerus resection in presence of nonunited
fracture humerus

22. Prognosis
 More favorable than for any other major nerve in
the upper extremity because
 it is predominantly a motor nerve
 muscles innervated by it are not involved in the
finer movements of the fingers and hand.

23.  Results of Suture of the Radial Nerve
 Only motor recovery is important in suture of the radial
nerve.
 89% obtain recovery of proximal muscles
 63% regain useful function of all muscles supplied by
the radial nerve,
 36% regain some fine control of the extensors of the
fingers and thumb.

24.  Critical Limit of Delay of Suture (Zachary)
 Radial nerve
 15 months.
 posterior interosseous nerve
 9 months

26. TENDON TRANSFERS FOR
RADIAL NERVE PALSY

27. Tendon
transfered
Tendon
transferred
to
Pronator
Teres
Extensor
Carpi
Radialis
Brevis
Flexor
Carpi
Radialis
Extensor
Digitorum
Communis
Palmaris
Longus
Extensor
Pollicis
Longus

29. Anatomy
 Formed by junction of lateral and medial root of
median nerve from the medial and lateral cords of
the brachial plexus in the axilla
 Composed of fibers from( C5), C6, C7, C8, and T1.
 From the sensory standpoint, they are more
disabling than injuries of the ulnar nerve because
they involve the digits used in fine volitional
activity

30.  After originating from the brachial
plexus in the axilla, the median nerve
descends down the arm, initially
lateral to the brachial artery.
 Halfway down the arm, the nerve
crosses over the brachial artery, and
becomes situated medially.
 The median nerve enters the anterior
compartment of the forearm via the
cubital fossa.
 In the forearm, the nerve travels
between the flexor digitorum
profundus and flexor digitorum
superficialis muscles.

31.  The median nerve gives rise to two major
branches in the forearm:
 Anterior interosseous nerve -
Supplies the deep muscles in the
anterior forearm.
 Palmar cutaneous nerve - Innervates
the skin of the lateral palm.
 The median nerve enters the hand via
the carpal tunnel, where it terminates
by dividing into two branches:
 Recurrent branch – Innervates the
thenar muscles.
 Palmar digital branch – Innervates
the palmar surface and fingertips of the
lateral three and half digits. Also
innervates the lateral two lumbrical
muscles.

33. Causes
 Lacerations, usually in forearm or wrist.
 In the upper arm,
 relatively superficial lacerations
 excessively tight tourniquets
 humeral fractures,
 when injured near axilla, the ulnar and
musculocutaneous nerves and the brachial artery also
are commonly injured.
 In the arm, the median nerve may be compressed by
the ligament of Struthers.

35.  At the elbow, the nerve may be injured in
 supracondylar fractures
 posterior dislocations of the elbow.
 Pronator syndrome
 At the wrist, the median nerve may be injured by
 fractures of the distal radius
 fractures and dislocations of the carpal bones.

36. Examination
 Pronator Teres,
 Flexor Carpi Radialis,
 Flexor Digitorum Profundus (Index),
 Flexor Pollicis Longus,
 Flexor Digitorum Sublimis,
 Abductor Pollicis Brevis.
 Substitution movements
 caused by action of intact muscles may cause
confusion during the examination.

37.  Usually, if the forearm
can be actively
maintained in
pronation against
resistance, the
pronator teres is
intact.

38.  If the wrist can be
actively maintained in
flexion, and a
contracting flexor
carpi radialis is
palpated, this muscle
is intact.

39.  if the interphalangeal
joint of the thumb can
be maintained in flexion
against resistance with
the wrist in the neutral
position and the thumb
adducted, the flexor
pollicis longus is
functioning.

40.  Although opposition
of the thumb can be
difficult to confirm, if
the thumb can be
actively maintained in
palmar abduction and
a contracting abductor
pollicis brevis is
palpated, this muscle
is functioning.

41.  The flexor digitorum
sublimis to each finger
is examined
separately, while the
remaining fingers are
held in full passive
extension.

42.  Sensory supply of the median nerve
 volar surface of thumb, index and middle fingers
 radial half of the ring finger
 dorsal surfaces of the distal phalanges of the index
and middle fingers are supplied by the median
nerve.
 autonomous zone
 dorsal and volar surfaces of the distal phalanges of
the index and middle fingers
 Autonomic changes
 Iodine starch test
 Ninhydrin print test.

43. Tendon Transfers
Median Nerve Palsy
 Classification
1) High
 Above Origin Of Anterior Interosseous Nerve
 Pronator Teres And Quadratus, FCR, FDS (II – V), FDP(II
& III) And FPL Paralyzed
2) Low
 Thenar Intrinsic Muscles Paralyzed
 Abductor Pollicis Brevis, Opponens Pollicis, And
Superficial Head Of Flexor Pollicis Brevis

44. TREATMENT
 If the onset of paralysis has been spontaneous, the
initial treatment is nonoperative.
 Surgical exploration
 indicated in absence of clinical or EMG improvement
after 12 weeks.
 If nerve injury is caused by a penetrating wound,
primary repair is recommended.
 In irreparable injury to the nerve, tendon transfers are
indicated

45. Results of Suture of the Median
Nerve
 Motor recovery is crucial after median nerve repair;
 Hand without median nerve sensory supply is
almost useless.
 Even with the best sensory recovery, the patient
probably will have difficulty with stereognosis.

46.  50 %patients with recover sensitivity to pain and
touch and some stereognosis
 90% of these patients recover a useful degree of motor
function in the long flexors of the forearm
 In more distal lesions, about two thirds attain some
useful motor recovery

47. CRITICAL LIMIT OF DELAY OF SUTURE
 Motor recovery in the intrinsic muscles of the hand
 9 months in high lesions
 12 months in low ones.
 Sensory recovery
 9 months in high lesions
 12 months in low ones
 may occur when suture has been delayed 2 years.
 Sensory return in children is possible, however, after
longer delays.

48. TENDON TRANSFERS
Median Nerve Palsy
 Reconstructive Goals
 Thumb Opposition
 FPL Function
 Index FDP Function
 Sensation
 Prime Determinant In Hand Function

49. Tendon Transfers
Low Median Nerve Palsy
 Deficit And Deformity
 Abduction And Opposition Frequently Retained
 Due To Diverse Innervation Of Intrinsics
 Median And Ulnar Nerves

50. Tendon Transfers: Opponenspalsty
 Standard Opponensplasties
1) FDS Opponensplasty
 Royle-Thompson Technique
 Bunnell Technique
2) Extensor Indicis Proprius Opponensplasty
3) Huber Transfer
 Abductor Digiti Minimi
4) Camitz Procedure
 Palmaris Longus

51. Tendon Transfers
Low Median Nerve Palsy
1) FDS Opponensplasty – Royle-Thompson
 FDS Brought Around Ulnar Border Of Palmar
Aponeurosis
 FDS Has A Large Potential Excursion
 Adjusting Tension Not As Critical
 Margin For Error

52. Tendon Transfers
Low Median Nerve Palsy
1) FDS Opponensplasty – Bunnel Technique
 Ring Finger FDS Divided
 FCU Exposed
 4cm Proximal To Pisiform Insertion
 Tendon Split Into Two Halves
 Free End Looped Back Onto Its Base
 Ensure Loop Not Too Tight

55. Tendon Transfers
Low Median Nerve Palsy
2) Extensor Indicis Proprius Opponensplasty
 Popular In High Median Nerve Palsy
 Ring And Middle FDS Unavailable
 Does Not Weaken Grip
 Tendon Must Be Superficial To FCU
 Avoid Compression To Ulnar Nerve

57. 3. Huber Transfer

58. Tendon Transfers
Low Median Nerve Palsy
4) Camitz Procedure
 Tfr of PL to APB
 Performed At Same Time As Carpal Tunnel Release
 Restores Palmar Abduction
 Palmaris Longus Usually Scarred

60. Tendon Transfers
High Median Nerve Palsy
 Deficit
 All Flexor Compartment Forearm Muscles
 Apart From Ulnar-Innervated FCU And FDP
 Aim Of Tendon Transfers
 Flexion Of Index And Thumb
 Opposition
 Potential Motors
 Brachioradialis  FPL
 ECRL  Index FDP

61. Tendon Transfers
High Median Nerve Palsy
 Extrinsic Transfers
 Restoration Of Index
Function
 ECRL  Index FDP
 Side-To-Side Suturing Of
Profundus Tendons
 Restores Range Of Motion
 Strength Is Not Restored

62. Tendon Transfers
High Median Nerve Palsy
 Extrinsic Transfers
 Restoration Of Thumb
Function
 Brachioradialis  FPL

63. Tendon Transfers
High Median Nerve Palsy
 Thumb Opposition
 Early Transfer
 Allows Pronation Of Hand
 Compensates For Loss Of Sensation
 Possible Transfers
 EIP
 EPL
 Extensor Digiti Minimi
 FCU – Eliminates Only Functioning Wrist Flexor

67. ANATOMY
 continuation of medial cord
 C7, C8, T1
 no branches in the upper
arm.
 enters the posterior
compartment of the upper
arm midway down its length
by piercing the medial
intermuscular septum,
 passes behind the medial
epicondyle of the humerus to
enter the forearm

68. ANATOMY
 Gives articular branch to
elbow
 descends to the wrist
deep to flexor carpi
ulnaris.
 supplies flexor carpi
ulnaris and the ulnar
half of flexor digitorum
profundus.

69. ANATOMY
 Just proximal to the
wrist it gives off a
dorsal cutaneous
branch that supplies
the skin over the
dorsal aspect of the
little finger and the
ulnar half of the ring
finger

70. ANATOMY
 crosses into the palm superficial
to the flexor retinaculum in
Guyon's canal.
 It divides into a
 motor branch, which supplies
the
 hypothenar muscles,
 the intrinsic muscles of the hand
(apart from the radial two
lumbricals)
 adductor pollicis, and
 cutaneous branches,
 supply the skin of the palmar
aspect of the little finger and the
ulnar half of the ring finger

71. Anatomy

72. Anatomy

73. Causes
 Axilla / upper arm :
 usually accompanied by other nerves and brachial artery
 Midarm :
 relatively protected
 Distal arm , elbow :
 Dislocation of elbow
 Supracondylar fractures
 Distal forearm/wrist :
 Gunshot , laceration , fractures or dislocations

74. Other causes
 Traction on nerve
 Subluxation or dislocation of nerve
 Entrapment syndrome
 Displaced fractures of medial humeral epicondyle
 Tardy ulnar nerve palsy
 Shallow ulnar groove on posterior aspect of medial humeral
epicondyle
 Hypoplasia of humeral epicondyle
 Inadequate fibrous arch
 Prolonged flexion at elbow
 Direct pressure during surgery

75. TYPES
 High ulnar nerve palsy:
 All extrinsic and intrinsic muscles affected
 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
 Low ulnar nerve palsy :
 Only deep intrinsic muscles affected
 No sensory loss over proximal and middle phalynx of little
and ring finger due to sparing of dorsal cutaneous branch

76. High ulnar palsy

77. LOW ULNAR NERVE PALSY

78. Examination
 “ Claw hand “ deformity : Benediction hand
 Flattened palm and wasting of hypothenar region
 Shallow midpalmar receptacle distal to thenar and hypothenar
eminences
 Longitudinal palmar furrows between prominent long flexors (
wasting of lumbricals )
 Concavities in intermetacarpal spaces
 Loss of sensation over the little finger and ulnar half of ring
finger
 Trophic changes , ulceration , brittle nails

80. Patho-anatomy of deformity
 Paralysis of interossei and lumbricals
Unopposed MCP joint extension & IP joint flexion by
digital extensors & flexors
 Without stabilization of MCP joints in neutral/slight
flexed position, long extensor function “blocked” at
MP joint by diversion of this tension to sagittal band,
producing hyperextension and effectively blocking the
extensor's ability to extend PIP joint.‡

81. Specific signs and tests for motor dysfunction
Duchenne's sign : Hyperextension at MCP joints &
flexion at IP joints of ulnar two fingers
 Bouvier’s maneuver : Dorsal pressure over proximal
phalanx to passively flex MP joint results in
straightening of distal joints and temporary
correction of claw deformity
 Extensor digitorum tendon can extend middle and
distal phalanges when proximal phalanx stabilized
Andre-Thomas sign : On palmar -flexon of wrist
exaggeration of deformity

82.  Pitres-Testut sign : Inability to actively move long
finger in radial and ulnar deviation with palm placed
flat
 Cross your fingers test : Inability to cross middle
finger dorsally over index finger, or index over
middle finger
Masse's sign: Flattened metacarpal arch and loss of
hypothenar elevation
 Wartenberg's sign : Inability to adduct extended
little finger to extended ring finger

83.  Jeanne’s sign : Hyperextension of MP joint of thumb
during key pinch or gross grip
Froment’s sign : Thumb IP joint flexion while
attempting to perform lateral pinch
Bunnell’s O sign : Combined hyperextension at MP
joint and hyperflexion of IP joint (noticed when
patient makes a pulp to pulp pinch with thumb and
index finger)

84. Examination

85. Examination

86. Examination

87. Examination

88. ANOMALOUS INNERVATION PATTERNS
 5 -10 % cases : FCU
innervated by C7
 Martin- Gruber
anastomosis :
 Between median and
ulnar Nerve
 Marinacci
Communication
 b/w ulnar and median in
forearm

89. ANOMALOUS INNERVATION PATTERNS
 Richie – Cannieu
anastomosis :
 Anomalous connection
between motor branch of
ulnar nerve and
recurrent branch of
median nerve near wrist
 Berretini anastomosis
 b/w common digital brs
of median & ulnar nerve

90. PRINCIPLES OF SURGERY
 Sensation recovers earlier than motor power after
suturing
 Critical limit of delay :
 motor :
 6-9 months for lesions at elbow
 12 -15 months for lesions at wrist
 Sensory :
 2 years
 Vascularity of the limb should be adequate , joints should be
fully mobile and power of muscles to be transferred should
be adequate
 No contractures permissible

91.  Nerve repair
 Transposition
 Medial epicondylectomy
 Reconstructive surgery
PRINCIPLES OF SURGERY

92. INCISION
 Nerve repair :
,
 Incision given over tendon of
pectoralis ,curving over natural
folds of axilla and then over
medial aspect of arm
 6-8 cm proximal to elbow ,
curve incision slightly
posteriorly
 Continue incision and
dissection along ulnar side of
volar aspect of forearm
 free it from FCU at its origin at
humeral epicondyle or resect
epicondyle
2 cm in wrist and 4 cm at
elbow can be overcome
by transposition
11 -15 cm by flexion of
elbow , wrists
Posterior splint or slab
needed for 2 -4 weeks

93. Principles of Surgery
 Transposition :
 With arm abducted and
externally rotated .
Incision made on
posteromedial surface of
elbow , 7 cm proximal to
epicondyle
 Reflect skin flap
anteriorly and identify
nerve in its groove
 Free FCU from its
humeral origin

94. Principles of Surgery
 Transposition :
 Identify branches to FCU
and FDP and dissect
them intraneurally
 nerve freed from Arcade
of Struthers till the point
where nerve lies between
2 heads of FCU
 Divide the tendinous
origin or medial
epicondyle for
submuscular transfer

95. Medial Epicondylectomy
Entire medial epicondyle and part of supracondylar ridge removed

96. RECONSTRUCTIVE SURGERY
 Deformities and deficiencies correctable by surgery
 Claw hand
 Unstable thumb
 Flattened or reversed distal transverse arch
 Loss of strong adduction of 1st metacarpal
 Loss of abduction of index finger
 Abnormal abduction of little finger
 Loss of sensibility in autonomous area of little finger
 Weakness of flexion in ulnar deviation of wrist
 Wasting of intermetacarpal spaces

97. Reconstruction
 Capsulodesis
 Prevent MCP
Hyperextension
 Dynamic
Procedures
 Static Tenodesis (Parkes)
 Prevents MCP
Hyperextension
 Provides IP Extension
 Tendon transfers

98. Zancolli
Capsulodesis
Volar MP joint Capsulodesis
 A1 pulley release with MP
joint volar plate advancement
 Complicated claw hands
with MP joint contracture
Zancolli incorporated collateral
ligament release on both sides
of MP joint with volar
capsuloplasty

99. METHODS OF CLAW HAND RECONSTRUCTION
Static procedures :
 To maintain MP joint in some degree of flexion
or to limit MP joint hyperextension
 claw posture reversed by functioning long
extensors
 Flexion of MP joint unrestricted in static
procedures

100. Proximal Phalangeal Flexion Static Techniques
 Fasciodermadesis ( Zancolli )‡
 Excision of 2 cm of the palmar skin (dermadesis) at
MP joint level combined with shortening of
pretendinous band of palmar aponeurosis
(fasciodermadesis) to correct claw hands with weak
extensors

101. Dorsal Methods (Howard; Mikhail)
To provide bony block to proximal phalangeal
extension
Enables long extensors to extend IP joints and correct
deformity.
Mikhail inserted bone block on dorsum of the
metacarpal head

102. Static Tenodesis Techniques
 Riordan
One half of ECRL and ECU tendons made use of
as “grafts” to prevent hyperextension of MP joint while
remaining half continue to actively extend wrist

103. Dynamic procedures:Integration of
Finger Flexion
Fowler tenodesis
 Incorporates active wrist motion
to tension static tendon grafts
 Free tendon grafts sutured to
extensor retinaculum of wrist
and passed in a dorsal to palmar
direction through the
intermetacarpal spaces, volar to
the DTML, through the
lumbrical canals, and onto the
lateral bands of dorsal extensor
expansion of 4 fingers

104. Tendon Transfers
Ulnar Nerve Palsy
 Wrist Motors For Proximal Phalanx Power
 Muslces Available
 ECRL
 ECRB
 Brachioradialis
 FCR
 Gross Grip Power Improved

106. Tendon Transfers
Ulnar Nerve Palsy
 Thumb-Index Key Pinch
 Requires Thumb Adduction And Flexion
 Loss Of Adductor And Interossei
 FPL And EPL Contribute
 Lesser Extent
 75 – 80% Loss With Ulnar Nerve Palsy
Arthrodesis Of MCP & IP Joints Of Thumb An Option

107. Tendon Transfers
High Ulnar Nerve Palsy
 Significant Deficit
 FCU And FDP Paralysis
 Decreased Power Grip
 Options
 FDP Paralysis
 Tenodesis Of Profundus Tendons
 FCU Paralysis
 Consider Transfer FCR To FCU

109. Tendon Transfers
Ulnar Nerve Palsy
 Preferred Transfers
1) Thumb Adduction
 ECRB  Adductor Tubercle Thumb
 FDS (Long)  Adductor Tubercle Thumb
2) Thumb-Index Tip Pinch
 APL  First Dorsal Interosseous & Arthrodesis Thumb
MP
 EPB  First Dorsal Interosseous & Arthrodesis Thumb
MP

111. Tendon Transfers
Ulnar Nerve Palsy
 Preferred Transfers
3) Clawed Fingers
 ECRL – Four Tailed Tendon Graft
 FCR – If Wrist Flexion Contracture
4) Distal Finger Flexion (High Palsy)
 FDP (Long) Tenodesed To FDP (Ring & Little)
5) Radial Wrist Flexion (High Palsy)
 FCR  FCU

112. BROWN’S 4 TAILED ECRL TFR

113. Sciatic Nerve

114. Sciatic Nerve
 Analogous to brachial
plexus.
 anterior primary rami of
L5, S1, S2, and S3
 trunk formed by the
posterior divisions form
common peroneal part
 trunk formed by the
anterior divisions becomes
the tibial part of the sciatic
nerve
 diameter 2 to 2.5 cm

115.  leaves pelvis through sciatic notch
 common peroneal part laterally and tibial part
medially
 descends deep to the gluteus maximus to the level of
the inferior gluteal fold
 follows a more superficial course to the distal third of
the thigh
 supplies articular branches to the hip joint&
hamstrings
 In apex of popliteal fossa, common peroneal part
leaves laterally to supply the short head of the biceps
femoris & deviates laterall
 larger tibial nerve, which continues distally in the
midline of the limb.

116. Mode of injury
 Hip
 gunshot wound to the thigh or buttock.
 posterior dislocation and fracture-dislocation of the hip,
 intramuscular injection into the buttock
 surgery around the hip joint.
 Compression of the sciatic nerve by wear debris from long-
standing total hip replacements
 Compression caused by anatomical variations in the
relationship of the nerve to the gluteal and piriformis muscles
and to the sciatic notch may cause sciatic pain.
 Thigh
 penetrating wounds and fractures of the femoral shaft.
 Peroneal half of the nerve is injured much more often than
is the entire nerve.

117. Examination
 Muscles supplied by the peroneal component
include the anterior tibial and the long extensors of
the toes (deep peroneal nerve) and the peroneus
longus and the peroneus brevis (superficial
peroneal nerve).

118.  Foot drop:
 equinus deformity of the foot, clawing of the toes, and
atrophy of the muscles innervated by the nerve,
depending on the level of the injury.
 Profound weakness of flexion of the knee,
 inability to dorsiflex the foot or extend the toes,
 inability to plantar flex and evert the foot,
 inability to flex the toes may be seen.
 Peroneal part: sensory loss primarily over the lateral
aspect of the leg and dorsum of the foot.
 When the tibial nerve is involved, the sensory deficit is
primarily over the plantar aspect of the foot.
 Autonomic disturbances and chronic pain may follow an
injury to the sciatic or tibial nerve..

119.  The autonomous zone of the
sciatic nerve includes
 metatarsal heads and over the
heel,
 the lateral and posterior
aspects of the sole of the foot,
 the dorsum of the foot as far
medially as the second
metatarsal,
 a narrow strip up the lateral
aspect of the leg.

121. Treatment
Methods of Closing Gaps
 Mobilizing the nerve : 15 cm
 flexing the knee
 hyperextending the hip.
 When the femur has been fractured and the sciatic nerve
divided, it is very important, even in the presence of
draining sinuses, to operate on the nerve before the femur
has united because, aside from the effect of time on the
nerve ends and muscles, the knee may stiffen, and it may
be impossible to flex it enough to close large defects.
 Resecting a part of the femur may be necessary to help
close the gap. When a fracture is present, such a resection
may be justified and can be done with ease.
 autogenous interfascicular nerve grafting
 especially in young patients.

122. After treatment
 immobilized in a double spica cast extending from the
nipple line to the toes

123.  Critical Limit of Delay of Suture
 12 to 15 months