orthopaedics and nerve injuries

1. MEDIAN NERVE INJURIES
DR. MAHAK JAIN
DNB RESIDENT

2. Median nerve introduction
 The median nerve is derived from both the lateral and
medial cords of the brachial plexus, with the lateral cord
providing mostly sensory axons from C6 and C7, and the
medial cord providing motor axons from C8 and T1.
 Also called labourer’s nerve.

3. Motor Functions
 The median nerve innervates the majority of the muscles in the anterior forearm, and
some intrinsic hand muscles.
 The Anterior Forearm
 In the forearm, the median nerve directly innervates muscles in the superficial and
intermediate layers:
 Superficial layer: Pronator teres, flexor carpi radialis and palmaris longus.
 Intermediate layer: Flexor digitorm superficialis.
 The median nerve also gives rise to the anterior interosseous nerve, which supplies the
deep flexors:
 Deep layer: Flexor pollicis longus, pronator quadratus, and the lateral half of the
flexor digitorum profundus (the medial half of the muscle is innervated by the ulnar
nerve).
 In general these muscles perform pronation of the forearm, flexion of the wrist and
flexion of the digits of the hand.

4. Cont:
HAND: The median nerve innervates some of the muscles in the hand via two
branches.
 The recurrent branch of the median nerve innervates the thenar muscles –
muscles associated with movements of the thumb.
 The palmar digital branch innervates the lateral twolumbricals – these muscles
perform flexion at the metacarpophalangeal joints of the index and middle
fingers

5. Innervation
•Motor
• superficial volar forearm group
• Pronator teres
• Flexor carpi radialis
• Palmaris longus
• intermediate group
• Flexor digitorum superficialis
• deep group
• Flexor digitorum profundus (lateral)
• Flexor pollicis longus
• Pronator quadratus
• hand
• 1st and 2nd lumbricals
• Opponens pollicis
• Abductor pollicis brevis
• Flexor pollicis brevis

6. Sensory innervation:
 The median nerve is responsible for the cutaneous
innervation of part of the hand. This is achieved via two
branches:
 Palmar cutaneous branch – Arises in the forearm and
travels into the hand. It innervates the lateral aspect of
the palm. This nerve does not pass through the carpal
tunnel, and is spared in carpal tunnel syndrome.
 Palmar digital cutaneous branch – Arises in the
hand. Innervates the palmar surface and fingertips of the
lateral three and half digits.

7. Course of median nerve
 Anterior compartment of arm
 anterior compartment (anteromedial to humerus)
 runs with brachial artery (lateral in upper arm / medial at elbow)
 no branches in the arm
 Forearm
 enters the forearm between the pronator teres and biceps tendon
 travels between flexor digitorum superficialis (FDS) and flexor digitorum
profundus (FDP)
 then emerges between the FDS and flexor pollicis longus (FPL)

8.  Hand
 the nerve then enters the hand via the carpal tunnel, along with the tendons of the
FDS, FDP and FPL
 Terminal branches
 anterior interosseous branch (AIN)
 innervates the deep volar compartment of forearm except the ulnar half of the FDP
 palmar cutaneous branch
 supplies sensory innervation to lateral palm
 recurrent branch (to thenar compartment)
 digital cutaneous branches
 supply the radial 3 1/2 digits (palmar)
 can also supply the index, long, and ring fingers dorsally

9. Clinical findings:
1. Injury at the Elbow: Supracondylar fracture of the humerus.
 Motor functions: The flexors and pronators in the forearm are paralysed, with the
exception of the flexor carpi ulnaris and medial half of flexor digitorum profundus.
The forearm constantly supinated, and flexion is weak (often accompanied by
adduction, because of the pull of the flexor carpi ulnaris). Flexion at the thumb is also
prevented, as both the longus and brevis muscles are paralysed.
 The lateral two lumbrical muscles are paralysed, and the patient will not be able to
flex at the MCP joints or extend at IP joints of the index and middle fingers.
 Sensory functions: Lack of sensation over the areas that the median nerve
innervates.
 Characteristic signs: The thenar eminence is wasted, due to atrophy of the thenar
muscles. If patient tries to make a fist, only the little and ring fingers can flex
completely. This results in a characteristic shape of the hand, known as hand of
benediction.

10. 2. Injury at the Wrist:
How it commonly occurs: Lacerations just proximal to
the flexor reticaculum.
Motor functions: Thenar muscles paralysed, as are the
lateral two lumbricals. This affects opposition of the
thumb and flexion of the index and middle fingers.
Sensory functions: Same as an injury at the elbow.

11. Median nerve clinical assessment:
1. Pronator teres (C6, C7) assessment: The patient’s forearm is extended and fully
pronated. The patient is then instructed to resist supination of the forearm by the
examiner.

12. 2. Flexor carpi radialis (C6, C7) assessment: The patient flexes the wrist
along the trajectory of the forearm. Wrist deviates ulnarly.

13. 3. Flexor digitorum superficialis (C8,
T1) assessment: To test proximal
interphalangeal joint flexion, the
supinated forearm and hand are
placed straight. This maneuver
places the finger to be tested
in mild flexion at the metacarpal–
phalangeal (knuckle) joint, and
stabilizes the remaining fingers in
extension, a position that allows
isolation of the flexor digitorum
superficialis. Ask the patient to flex
PIP jt against resistance.

14. 4. Flexor digitorum profundus (C8, T1) assessment: To assess the median
innervation of the flexor digitorum profundus one should concentrate on the
index finger. To do so, hold the metacarpal-phalangeal and proximal
interphalangeal joints immobile, and have the patient flex the distal phalanx
against your resistance.

15. Ochsner’s clasping test: flexor digitorum superficialis and profundus(
lateral half)

16. The Thenar Group
5. Flexor pollicis longus (C8, T1) assessment: Immobilize the thumb, except the
interphalangeal joint, and then ask the patient to flex the distal phalanx against
resistance.

17. 6. Okay” or “circle” sign with anterior interosseous
nerve weakness.
 A quick way to assess the flexor digitorum
profundus and flexor pollicis longus innervation
from the anterior interosseous nerve is to ask the
patient to make an okay sign by touching the tips
of the thumb and index finger together.
 With weakness in these muscles, the distal
phalanges cannot flex, and instead of the
fingertips touching, the volar surfaces of each
distal phalanx make contact.

18. 7.Pronator quadratus (C7, C8) assessment
 : Have the patient resist supination of a fully flexed and
pronated forearm. With full forearm flexion, pronation
by the usually dominant pronator teres is minimized.

19. 8. Abductor pollicis brevis (C8, T1) assessment: Resist movement of the thumb
away from the plane of the palm (palmar abduction), while stabilizing the
metacarpals of the
remaining fingers.

20. 9. Flexor pollicis brevis (C8, T1)
assessment
 The patient flexes the thumb at the metacarpal-
phalangeal joint against resistance placed over
both the proximal and distal phalanges.
 Make certain the distal interphalangeal joint does
not flex because in allowing this, substitution by
the flexor pollicis longus occurs.
 Use your other hand to immobilize the first
metacarpal to reduce substitution by the
opponens pollicis.
 Because of its dual innervation, even with
complete thenar motor branch palsies some
thumb flexion still occurs.

21. 10: Opponens pollicis (C8, T1)
assessment:
 Have the patient forcibly maintain
contact between the volar pads of the
distal thumb and fifth digit, while you try
to pull the distal first metacarpal away
from the fifth digit. Although thumb
opposition is only innervated by the
median nerve, a combination of thumb
adduction (adductor pollicis, ulnar nerve)
and thumb flexion (flexor pollicis brevis,
deep head, ulnar nerve) may mimic
thumb opposition even when there is
complete median nerve palsy present.

22.  11. Lumbrical of second digit (C8,
T1) assessment:
 Stabilize the patient’s index finger
in a hyper-extended position at
the metacarpal-phalangeal joint
and then provide resistance as
the patient extends the finger at
the MCP joint.

23. Sensory system examination
 Modality test – pain,touch,temperature ,pressure and
vibration
 Functional tests –two point discrimination ,seddons
coin test ,ridge sensitometer
 Objective test –
 (a) sweat test (iodine starch test)-
 dusting extremities with quinizarine powder
 In denervated area powder remain dry and light gray
 In normal sweating area it become deep purple colour

24. (b)Skin resistance test
Richter dermometer is used
Absence of sweating demonstrate increased
resistance to passage of electric current
(c)wrinkle test
denervated skin do not wrinkle on exposure
to water for prolonged period ( 4*C for 30
min.)

25. • (d) Tinel’s sign-
– tested by gentle percussion along course of nerve
from distal to proximal direction.
– Tingling sensation felt by patient in distribution of
nerve.
– Tingling should persist for several seconds
• Importance of Tinel’s sign
– Whether Nerve interrupted
– Whether in Process of regeneration
– Rate of regeneration
– Success of nerve repair

26. Electrophysiological study
 Electromyography
Around 3 wks after denervation, the muscle
fibres will twitch rhythmically and involuntarily
These fibrillations cannot be seen clinically but
can be measured by EMG
Fibrillations are called denervation fibrillation

27. • Nerve conduction test
– First calculate threshold by stimulating on sound side
– If twice the threshold fails to produce muscle contraction
nerve conduction is absent
– Slow rate of conduction suggest damage to nerve
• Compound muscle action potential can be recorded from both
proximal and distal Forearm extensor muscles

28. CLASSIFICATION OF NERVE INJURIES
SEDDON’S CLASSIFICATION
Neuropraxia – temporary paralysis of a nerve
caused by lack of blood flow or by pressure
on the affected nerve with no loss of structural
continuity.
Axonotmesis – neural tube is intact but axons
are disrupted. Nerves are likely to recover.
Neurotmesis – neural tube is severed. Injuries
are likely to be permanent without repair.

29. SUNDERLAND’S CLASSIFICATION

30. Median nerve Compression Syndromes
 Carpal Tunnel
 Pronator Teres
 Anterior Interosseous

31. Carpal Tunnel Syndrome
 Compressive neuropathy as the nerve passes through the Carpal Tunnel
 Causes:
- Idiopathic : Most common
- Inflammatory : Rheumatoid Arthritis
: Wrist osteoarthritis
- Post traumatic : Bone thickening
- Endocrine : Myxoedema
: Acromegaly
- Pregnancy
- Gout
- Repetitive wrist movts: Typists & Computer users

32. Carpal Tunnel

33. Symptoms
 Hand and wrist Pain
 Paraesthesia
 Hypoaesthsia
 Sparing of Palmar cutaneous branch supply
 Patient wakes at night with burning or aching pain and shakes the hand to
obtain relief and restore sensation
 Aggravated by elevation of hand
 Thenar atrophy and weakness of thumb opposition and abduction may
develop late

34. Diagnosis
 History
 Clinical examination:
- Thenar wasting
- Phalen’s sign
- Tinel’s sign
- Carpal compression test
 Electro Diagnostic Studies:
- Very reliable for evaluation
- Atypical cases may be present

35. Thenar atrophy

37. Tinel’s Sign

38. Carpal Compression test/ Durkan’s test

39. Management
• Splinting – prevents wrist flexion
• Corticosteroid/anesthetic injection
• Surgical decompression:Division of the transverse carpal ligament
- Open
- Endoscopic

43. Complications
 Injury to palmar cutaneous/recurrent motor branch of the median nerve
 Hypertrophic scarring
 Hematoma/Arterial injury

44. Pronator teres syndrome
• High Compression neuropathy
• It is rare compared to CTS and AIS
• Misnomer  Proximal forearm median nerve compression

45. Symptoms & signs
 Symptoms are similar to those of carpal tunnel syndrome
 Sensory disturbances
- Thumb & Index > Middle finger
 Night pain is unusual and forearm pain is more common
 Hand numbness on gripping
 Phalen’s test negative
 Symptoms provoked by resisted elbow flexion with forearm
supinated ( tightening of bicipital aponeurosis )
 By resisted forearm pronation with the elbow extended
( pronator tension )

46. Management
 No relief with steroids
 Surgical decompression

47. Anterior Interosseous Syndrome
 Damage to the Anterior Interosseous Nerve
 Pain in the forearm
 Weakness of the gripping movement of the thumb and index finger(
unable to make ok sign )
 Causes:
- Injury to elbow
- Injury during open/closed reduction

48. Management
 Corticosteroids
 Surgery:
- Resection/detachment of deep head of PT

49. Tendon transfer in median nerve injuries
 Median nerve palsy is perhaps the most devastating single nerve injury of the
upper extremity. Not only is there a loss of fine motor control and opposition,
but sensibility is lost over the area of the hand used for precision movements
and prehensile functioning.
 Tendon transfer procedures to restore movement may be ineffective if
sensibility cannot be restored.
 High median nerve palsy is defined as an injury proximal to the innervation of
the forearm muscles. Although PT and FCR functions are lost, forearm pronation
and wrist flexion are compensated for by other muscles, and do not need to be
restored.

50.  Although the FDS to all four fingers is lost, flexion is maintained in the ring
and small fingers by the functioning ulnar-innervated FDP muscle bellies.
However, even though ring and small finger flexion is preserved, grip strength
is diminished.
 More importantly, there is a loss of thumb IPJ flexion and index and middle
finger DIPJ flexion due to loss of the AIN innervated muscles. This results in a
lack of fine motor control of the hand, which is normally provided by precise
movements of the IPJ of the thumb and the IPJ’s of the index and middle
fingers.
 In addition to these deficits, crucial thumb opposition is lost.
 Low median nerve palsy, on the other hand, results in loss of thumb
opposition and sensory loss only. The fact that some degree of sensory
reinnervation is likely when a low median nerve injury has been repaired
makes this a potentially less devastating injury than high median nerve palsy.

51. General indications of surgery
In sharp injury exploration for diagnostic as well
as theurapeutic purpose .Nerorrhaphy can be
done at time of exploration or delayed
In avulsion or blast injury –to identify and suture
of nerve ends for delayed repair
No improvement since last 12 weeks following
close injury

52. Time of surgery
Primary repair within 6-8 hours gives best
results
Delayed primary repair – between 7- 18 days
Secondary repair - 3 to 6 weeks later
.preferable in crushed ,avulsed,contaminated
wounds where patients life is seriously
endangerd

53. Surgical techniques
Coaptation
Approximating the cut ends of nerve in
such a way that motor fasiculi meets
another motor fasiculi and sensory to
sensory
Conventionally done by 8-0 to 10-0 nylon
suture
Sutureless methods includes fibrin clots,
adhesive tapes ,collagen tubulization

54. Neurolysis
Neurolysis is dissection to free nerve fibers
 Exo Neurolysis-
removal of neuroma or binding cicatrix
 Endo Neurolysis-
seperation of of each of fasciculi from
surrounding non fascicular tissue

55. Neurorrhaphy
Neurorrhaphy is end to end suturing of nerve
 Types
Partial Neurorrhaphy
Epineural Neurorrhaphy
Perineural (fascicular) Neurorrhaphy
Epiperineural Neurorrhaphy
Interfascicular nerve grafting

56. Epineural neurorrhaphy

57. Perineural neurorrhaphy

58. Epiperineural neurorrhaphy

59. Inter fascicular nerve grafting

60. Nerve grafting
 A gap between cut ends more than 2.5-4 cm is
indication of nerve graft
 Types of grafts
Trunk graft
Cable graft
Pedicle nerve graft
Inter fascicular nerve graft
Pre vascularised nerve graft

61. Critical Limit of Delay of Suture
 Return of motor function should not be
expected when suture has been delayed for
more than 15 months.

62. Reconstructive procedure
 1 Tendon transfer
 2 Arthrodesis
 When neighboring tendons are intact and if all criteria for
tendon transfer met ,then tendon transfer is treatment of
choice
 Tendon transfer should be delayed for 6 months

63. Criteria for tendon transfer
– Muscle power grade 5 (preferably),if not atleast grade 4
– Should have its own nerve and blood supply
– Synergistic group are chosen because of easier rehabilitation
– Age should be more than 5 years
– Disease should not progress and infection to be controlled
– Prior to transfer joint stiffness,contracture and malunion are
corrected
– Tendon transferred should not be at an acute angle

64. 1. Restoring thumb opposition:
 The most devastating loss of movement following high or low median nerve
injury is the loss of thumb opposition. This can be restored with an
opponensplasty, or opposition transfer.
 Thumb opposition is a complex movement that involves palmar abduction,
pronation, and flexion of the thumb metacarpal and proximal phalanx.
 The ideal insertion for an opposition transfer is the APB insertion. Insertion at
this point most reliably causes the combination of movements that result in
thumb opposition.
 The angle of pull should be from the location of the pisiform, because this
approximates the normal direction of pull of the APB.
 A pulley is often necessary to create the proper line of pull. The transverse
carpal ligament, the palmar fascia edge, a loop of the FCU tendon, and the FCU
tendon itself have all been used as pulleys

65. The superficialis opponensplasty
 described by Royle in 1938,
 involves dividing the ring inger FDS distally in the finger,
retrieving the FDS proximal to the carpal tunnel, re-directing the
tendon distally through the FPL sheath, and inserting it into the
thumb.
 The main disadvantage of the superficialis opponensplasty is
that it can only be used in cases of low median nerve palsy,
because the FDS is paralyzed in high median nerve palsy

66. Superficialis opponensplasty using
ring finger FDS for restoration of
opposition in low median nerve
palsy.

67. The EIP(extensor indicis propius)opponensplasty:
 in cases of both low and high median nerve injury, and is the most commonly
employed opposition transfer in high median nerve palsy
 Although the EIP is a weak motor, it is sufficiently strong to move the thumb
into opposition.
 The EIP is tunneled around the ulnar aspect of the wrist, routed across the
palm from the level of the pisiform, and inserted on the APB.
 It is important to close the extensor hood of the index MCPJ after EIP harvest
to prevent postoperative extension lag at the index MCPJ.
 Functional loss with the EIP transfer is minimal, and retraining the EIP to
perform thumb opposition is not difficult.

68. EIP opponensplasty for restoration of
opposition in high median nerve palsy.

69. The Huber transfer:
 employs the ulnar nerve-innervated abductor digiti minimi (ADM) to restore
opposition.
 This transfer is usually used in cases of congenital absence of the thenar
muscles, and in cases where the FDS and EIP are not available.
 The ADM is released from its insertion, turned over 180 degrees, and inserted on
the APB insertion.
 Strength and excursion are well matched to the deficit, and the transfer is
synergistic

70. HUBER PROCEDURE:

71. Restoring Thumb IPJ flexion and index
finger DIPJ flexion
 In cases of high median nerve injury, thumb IPJ flexion and index finger DIPJ
flexion can be restored with transfer of the BR, the ECRL, or ECU.
 The most common transfers are BR to FPL and ECRL to index FDP. However, it
should be remembered that reinnervation of the FPL and FDP is common after
a high median nerve injury has been repaired.
 If a return of function is anticipated, an end-to-side transfer should be
performed.
 If recovery is not expected, an end-to-end transfer results in a more direct line
of pull.

72. Rehabilitation:
 First 4 weeks:
 splint that should take tension off the tendon transfer(s) performed. For example, if a transfer was
performed to improve clawing, the splint should keep the MCPJ’s flexed and the IPJ’s extended.
 maintain mobility in the non-immobilized joints of the upper extremity.
 After 4 weeks:
Mobilization should start with gentle active and assisted range of motion exercises. It is important to mobilize one joint at a
time to prevent placing too much tension on the transfer. For example, if an ECRB transfer to treat clawing was performed,
the therapist should mobilize the MCPJ’s while keeping the wrist and IPJ’s immobile.
 6 weeks: exercises that activate the muscles used in the tendon transfer, and should begin muscle
retraining. Electrical stimulation and biofeedback may be used to assist with retraining.
 8 weeks: At eight weeks postoperatively, strengthening exercises should be initiated, and the splint
can be weaned off over the next four weeks.
 Full activity is resumed at twelve weeks.

73. COMPLICATIONS:
 Tendon adhesions,
 transfer rupture,
 Transfer weakness
 Infection
 Neuro vascular injuries

74. Thank you