1. Peripheral Nerve Injuries Treatment
General Principles
Repair
Graft
Tendon Transfer Principles
By Dr Kota Gandhi
III yr PG Orthopaedics
Kamineni Institute Of Medical Sciences
2. General considerations of treatment of
Nerve Injuries
Initial management of a patient with peripheral nerve
damage should begin with careful assessment of the vital
functions.
When the extent of any injury to the major viscera has been
determined, and appropriate resuscitative measures have
been started, the injury to the peripheral nerve should be
evaluated and the specific nerve deficit should be assessed
carefully.
Management depends on whether injury is Open or Closed
3. Open Injury
An open wound with peripheral nerve injury should be
cleansed and debrided thoroughly.
Immediate primary repair
Clean and sharply incised
Patient condition satisfactory
Adequate personnel and equipment
Delayed primary repair (after 3-7 days)
4. Open Injury
Secondary repair
• Contamination is severe
• Crushing, abrading or blast injuries.
Wound cleaned, debrided and sterile dressing applied.
Ends of nerve marked with proline or stainless steel.
Loose end to end apposition to prevent retraction.
In the presence of a segmental gap in the nerve, suturing the
end to end the soft tissues prevents their retraction.
5. Closed injury
• Assessment of residual function and documentation of
discrete deficit.
• Early active motion of all joints
• Gentle passive exercises
• All joints of the extremity must be kept supple, and soft
tissue contracture must be avoided
• Dynamic and static splinting to support joints and to prevent
contracture.
6. Closed injury with fracture
• Early surgical exploration is avoided unless open reduction planned.
• Awaiting re-inner action seems reasonable
• Early ultrasound imaging of the involved nerve can determine the extent
of injury.
• Periodic EMG, nerve conduction velocity studies, and frequent clinical
evaluation.
• If no evidence of regeneration then nerve exploration.
• If the nerve deficit follows manipulation or casting of a closed fracture in
the absence of prior nerve deficit, early exploration of the nerve is
indicated.
7. Factors influencing regeneration after
neurorrhaphy
1. Age
• Neurorrhaphies are more successful in children than in adults and are more likely to
fail in elderly.
• This is not understood completely but may relate to the potential for central
adaptation to the peripheral nerve injury.
2. Gap between nerve ends
• Recovery better if gap is small.
• Nature of injury is most important factor in determining extent of defect
• Sharp cut injury - proximal and distal end damage limited – minimal resection and gap
• High velocity injury – proximal and distal damage extensive- wide resection and gap
• Nerve grafting is advised if, after nerve is mobilised, the gap cannot be closed by
flexing the main joint of the limb 90 degree.
8. Factors influencing regeneration after
neurorrhaphy
3. Level of injury
• More proximal the injury, the more incomplete the overall return of the motor
and sensory function, especially in the more distal structures.
4. Delay between time of injury and nerve repair
• Delay of neurorrhaphy affects motor recovery more than sensory recovery.
• Significant loss of motor end plates and increased muscle fibrosis by 18 months
after enervation.
5. Condition of nerve ends
• The condition of the nerve ends at the time of neurorrhaphy is important.
• Meticulous handling of the nerve ends, asepsis, care with nerve mobilization,
preservation of neural blood supply, avoidance of tension, and provision of a
suitable bed with minimal scar all exert favorable influences on nerve
regeneration.
9. Methods of closing troublesome gaps include
(1) nerve mobilization
(2) nerve transposition
(3) joint flexion
(4) nerve grafts
(5) bone shortening.
10. Indications
In the presence of a traumatic peripheral nerve deficit, exploration of
the nerve is indicated as follows:
1.When a sharp injury has obviously divided a nerve, early exploration
is indicated for diagnostic, therapeutic, and prognostic purposes.
Neurorrhaphy can be done at the time of exploration or can be
delayed.
2. When abrading, avulsing, or blasting wounds have rendered the
condition of the nerve unknown, exploration is required for
identification of the nerve injury and for marking the ends of the
nerve with sutures for later repair.
11. 3. When a nerve deficit follows blunt or closed trauma and no clinical or
electrical evidence of regeneration has occurred after an appropriate time,
exploration of the nerve is indicated. This also is true when a nerve deficit
complicates a closed fracture. Observe and then if regeneration has not
occurred, exploration is favoured. In situations in which a nerve has been
intact before closed reduction and casting of a fracture, but a significant
deficit is found immediately after, explore the nerve as soon as feasible.
4. When a nerve deficit follows a penetrating wound, such as that caused by
a low-velocity gunshot, the part is observed for evidence of nerve
regeneration for an appropriate time. If there is no evidence of regeneration,
exploration is indicated.
Conversely, delay in exploration of a nerve injury is indicated if progressive
regeneration is evidenced by improvement in sensation, motor power, and
electrodiagnostic tests and by progression of the Tinel sign
12. Time of Surgery
The controversy concerning whether primary or secondary
nerve repair is better is unresolved.
Primary repair done in the first 6 to 8 hours or delayed primary
repair done in the first 7 to 18 days is appropriate when the
injury is caused by a sharp object, the wound is clean, and there
are no other major complicating injuries.
When the diagnosis of division of a peripheral nerve has been
made, if conditions are suitable and repair is indicated, one
should not delay repair in anticipation of spontaneous
regeneration.
Only if the patient’s life or limb is seriously endangered should
the operation be long postponed.
13. A fracture is not a contraindication for operation. Operation
before the fracture becomes united may be advantageous
for two reasons:
(1) if bone shortening is necessary, resection of an
ununited or partially united fracture is a much less
formidable procedure than resection of a fully united
bone;
(2) Restriction of joint motion is minimal if the nerve is
repaired soon after the injury; later, motion would be
more limited, perhaps so severely as to prevent flexing
the joint enough to overcome a gap between the nerve
ends.
14. Instruments and Equipment
• A nerve stimulator should be available for all peripheral
nerve procedures; many satisfactory permanent and
disposable ones are available commercially.
• A stimulator is indispensable in investigating partially
severed nerves and neuromas in continuity and in locating
and preserving nerve branches given off proximal to or at
the lesion that are still functioning but are encased in scar
tissue.
• Instruments for handling and dissecting delicate tissues
always are essential.
15. • Gelfoam and thrombin are useful for controlling the bleeding
from the cut ends of nerves.
• For suture material 8-0, 9-0, and 10-0 monofilament nylon
are preferable .
• The tensile strength, easy handling qualities, and minimal
tissue reaction to nylon make it the most desirable suture
material now available for neurorrhaphy.
• Most epineurial repairs are best done with 8-0 or 9-0 nylon.
• For perineurial or epiperineurial repair, 9-0 or 10-0
monofilament nylon is preferable.
16. Preparation and Draping
Before preparing and draping, the correct side and site are
identified and the site is marked with an indelible surgical
marking pen.
Because the exact length of an incision can rarely be predicted, it
is mandatory that the entire extremity and its environs be
prepared.
For an operation on the upper extremity, the axilla, shoulder,
neck, and chest should be included in the field of preparation; for
an operation on the lower extremity, the buttock and the area up
to the iliac crest posteriorly should be included.
17. Principles of Nerve Repair
• In no type of surgery is the incision more important. Every
incision should extend well proximal and distal to the lesion and
when possible should follow the course of the nerve.
• Preparation of nerve stump and approximation without tension
to preserve blood supply.
• Consider normal excursion of the nerve with limb movements.
• Extremity should be moved through ROM during repair itself.
• Lacerated fascicles must be dissected proximal and distally until
adequate exposure is obtained for repair.
• Epineural vessels must be preserved because they serve as an
important guide for fascicular orientation during repair.
18. A technically perfect nerve repair must consist of
four parameters
(1) Complete debridement to healthy nerve
tissue,
(2) Nerve approximation without tension,
(3) End-on alignment of fascicles,
(4) Atraumatic and secure mechanical coaptation
of nerve ends.
19. • Neurolysis has paramount importance in surgical repair of nerve
injuries.
• External neurolysis which essentially involves dissection outside
the epineurium to release it from points of compression or
tethering due to scarring, particularly in cases of delayed
exploration.
• This will enable sufficient mobilization of the nerve, which is a
critical step prior to any form of coaptation.
• Sufficient exposure of the injured segment, both proximal and
distal, is mandatory prior to neurolysis. Dissection is preferably
performed toward the injury site from a normal segment of the
nerve.
• Adequate neurolysis is believed to act in concert with a healthy
vascularized bed to improve nerve vascularity, thus enhancing
Neurolysis
20. Direct Repair
• This type of repair is attempted when the severed ends can be
approximated without tension and when the gap is minimal.
• A better outcome is observed when the nerves are exclusively motor
or sensory and also when the amount of intraneural connective tissue
is relatively less.
• External neurolysis should be performed without causing neural
damage, as mentioned earlier. The repair should be achieved
with minimal tension.
• Due to the elastic nature of nerves, some degree of tension is
expected in every repair. The amount of acceptable tension is,
however, not properly defined.
• De Medinaceli and colleagues reported that failure to hold an end-to-
end repair with single 9–0 suture is a sign of excessive tension.
• Whenever there is excess tension at repair site, nerve grafting is
21. End-to-End Repair
This is one of the most widely used techniques for direct nerve repair.
Epineural repair: This technique is commonly used when there is a sharp
injury to the proximal portion of the nerves without nerve loss and also in
cases of partial injuries with good fascicle alignment.
It is highly effective for mono fascicular and diffusely grouped poly fascicular
nerve repairs.
The primary goal is to achieve continuity of the nerve stumps without
tension, along with proper alignment of the fascicles. The correct fascicle
positioning is confirmed by aligning the longitudinal blood vessels in the
epineurium.
The coaptation is performed using 8–0 or 9–0 nylon sutures under
magnification. To begin with, two orienting epineural sutures are taken 180
degrees apart to avoid rotational displacement during mobilization.
22.
23. Grouped fascicular repair: This technique is used in mixed motor and
sensory nerves where the fascicles serving specific functions are well
are well formed and easily recognized
The external epineurium is reflected back to organize the fascicles.
Fascicular coaptation is achieved with placement of sutures in the
interfascicular epineurium and perineurium with 8–0 to 10–0 nylon
sutures.
It is imperative to keep the tension at the repair site to the utmost
minimum as the interfascicular epineurium is not as tough as the external
epineurium.
24.
25. Fascicular repair: This technique is used in a clean lacerating injury, where the
motor and sensory fascicles can be easily identified, in the partially damaged nerve.
damaged nerve. This involves coaptation of the individual fascicles for optimal
optimal alignment, and hence this is a more technically difficult repair.
Fascicular coaptation is achieved under high magnification by placement of sutures,
usually two to three 10–0 or 11–0 nylon sutures 120 to 180 degrees apart, in the
perineurium. It is important to avoid injury to the endoneurium during suture
placement.
Unlike epineural repair, both grouped fascicular and fascicular coaptation provides
better alignment of the fascicles, thereby reducing misdirection of axons.
Nevertheless, the additional dissection and increased sutures involved in this
technique could potentially lead to increased scarring and disruption of blood
supply
26.
27. End-to-Side Repair
End-to-side or terminolateral neurorrhaphy involves connecting
the distal stump of a transected nerve, referred to as the acceptor
nerve, to the side of an intact adjacent or neighboring nerve,
referred to as the donor nerve.
This technique is particularly useful in sensory nerve transfers and
facial nerve reanimation.
The advantage of this technique is that there is no length limitation
and also that there is recovery of injured nerve without
compromising the function of donor nerve.
29. Nerve grafting
Sources
• Lateral cutaneous nerve of thigh
• Medial brachial and ante brachial cutaneous nerve
• Radial sensory nerve
• Sural nerve (up to 40 cm)
• Lateral cutaneous nerve of forearm
• Terminal branches of PIN ( for digital nerves)
30. Nerve grafting techniques
1. Trunk grafting
• Using full thickness segment of major nerve trunk
2. Inter fasicular nerve graft
• Cable graft using multiple strands of cut nerve
3. Pedicle graft
• For high combined and median nerve palsy where ulnar nerve is used a
pedicel graft to repair median nerve.
4. Free vascularised nerve graft
5. Biological conduits +/- stem cells
6. Artificial conduits
• Collagen
• Poly glycolic acid
• Poly L lactic acid
31.
32.
33. TENDON TRANSFER
A tendon transfer procedure relocates the insertion of a
functioning muscle-tendon unit (MTU) in order to restore
lost movement and function at another site.
34. Indications
Most common indication: is a peripheral nerve injury that has no potential
to improve. This includes nerve injuries that are physically irreparable such
as root avulsions, nerve injuries that do not recover after direct nerve
repair or grafting, or failed nerve transfers.
When peripheral nerve injuries present so late that muscle re-innervation
is impossible due to motor end-plate fibrosis.
Other common indications:
• Include loss of muscle or tendon following trauma,
• central neurologic deficits such as spinal cord injuries and cerebral palsy
• tendon ruptures in patients with rheumatoid arthritis.
• rarer disorders, including poliomyelitis and leprosy
35. Principles and pre-requisites of tendon transfer
1) supple joints prior to transfer
2) soft tissue equilibrium,
3) donor of adequate excursion,
4) donor of adequate strength,
5) expendable donor,
6) straight line of pull,
7) synergy,
8) single function per transfer
36. 1.Supple joints prior to transfer:
The joint that the tendon transfer will move must have maximum
passive range of motion prior to the procedure.
A tendon transfer procedure will fail if the joint has become stiff.
Often, aggressive therapy is required to achieve and maintain a
supple joint before performing a tendon transfer procedure.
If contracture release is necessary, it should be performed prior to
the tendon transfer procedure, and should be followed by
intensive therapy to maintain range of motion.
Because immobilization is required after a tendon transfer
procedure to allow healing of the tendon juncture, contracture
release should not be performed at the same time
37. 2. Soft tissue equilibrium
The principle of soft tissue equilibrium refers to the idea that a
tendon transfer should pass through a healthy bed of tissue that
is free from inflammation, edema, and scar. This is necessary to
allow the tendon to glide freely and to minimize adhesions.
Following a soft tissue injury, the surgeon must allow enough
time to pass for the inflammation and edema to fully subside.
If the planned tendon transfer must pass through an area of
severely scarred tissue, the scar should be excised and replaced
with a flap, or an alternative transfer through a healthier bed
should be considered.
38. 3. Donor of adequate excursion
The excursion or maximum linear movement of the transferred
MTU should be adequate to achieve the desired hand movement.
This means that the transferred MTU should have an excursion
similar to that of the tendon which it is replacing.
Most of the time, a donor MTU with adequate excursion will be
available for transfer. However, in some situations none of the
available donor MTU’s have the required excursion. In these cases,
the tenodesis effect can often be used to augment the excursion of
the transferred tendon.
40. 4.Donor of adequate strength
the MTU to be transferred must be strong enough to achieve the
desired movement, but at the same time, should not be too strong..
When evaluating potential donor MTU’s, it is easiest to compare
their relative strength as opposed to absolute strength.
The flexor carpi radialis (FCR), wrist extensors, finger flexors, and
pronator teres (PT) all have a relative strength of 1.
The brachioradialis (BR) and flexor carpi ulnaris (FCU) are stronger,
and have a relative strength of 2.
Finger extensors are weaker and have a relative strength of 0.5.
The abductor pollicis longus (APL), extensor pollicis longus (EPL),
extensor pollicis brevis (EPB), and palmaris longus (PL) are all
weaker still, with relative strengths of 0.1
41. 5.Expendable donor
The principle of using an expendable MTU as a donor means
that there must be another remaining muscle that can
continue to adequately perform the transferred MTU’s
original function.
For example, the wrist has three extensors, the extensor
carpi ulnaris (ECU), the extensor carpi radialis longus (ECRL),
and the extensor carpi radialis brevis (ECRB). If all three are
functional, one or two of the extensors can be transferred.
Although wrist extension will be weakened, it will not be lost
as long as there is one remaining extensor.
42. 6. Straight line of pull
Tendon transfer procedures are most effective if there is a straight line of
pull. This is because direction changes diminish the force that the
transferred MTU is able to exert on its insertion.
A change in direction of just 40 degrees will result in a clinically significant
loss of force.
Assuming that all other factors are equal, the end-to-end transfer will result
in better function and force transfer than the end-to-side transfer, because
the line of pull is straighter.
However if a direction change is unavoidable or even necessary. In these
cases, the tendon should be passed around a fixed, smooth structure that
can act as a pulley
43. 7. Synergy
The principle of synergy refers to the fact that certain muscle
groups usually work together to perform a function or
movement. Wrist flexion and finger extension are synergistic
movements that often occur simultaneously during normal
activity. When one flexes the wrist, the fingers automatically
extend. Wrist extension and finger flexion are similarly
synergistic.
Finger flexion and extension, however, do not normally occur
together and are not synergistic movements. Transferring a
wrist flexor to restore finger extension adheres to the principle
of synergy, whereas using a finger flexor to provide finger
extension does not. A synergistic transfer is preferable,
although sometimes a non-synergistic transfer is the only
available option.
44. 8. Single function per transfer
The final principle is that a single tendon should be used
to restore a single function. Transfer of one MTU to restore
multiple functions will result in compromised strength and
movement.
The exception to this rule is that a single MTU can be
used to restore the same movement in more than one
digit. For example, the FCU cannot be used to power wrist
and finger extension, or to power finger extension and
thumb abduction. However, it can be used to power the
extension of all four fingers.
45. Timing of tendon transfer
The timing of a tendon transfer after an injury depends on the likelihood
of spontaneous reinnervation and nerve recovery. If nerve repairs or
nerve transfers were performed initially, then sufficient time should be
allowed to determine the outcome of the initial treatment before
considering tendon transfers. Keep in mind that axons regenerate at a
rate of approximately 1 mm/d.
Of note, some hand surgeons advocate early tendon transfers,
particularly in patients with radial nerve palsies, even if recovery is still
possible.
In 1974, Burkhalter reported that the indications are (1) the transfer can
act as a substitute during regrowth of the nerve, which will thereby reduce
the time of external splinting and improve early function; (2) the transfer
can act as a helper and add power to normal reinnervated muscle
function; and (3) the transfer can act as a substitute when, statistically,
the recovery after neurorrhaphy or nerve repair is poor.
46. CONTRAINDICATIONS
The only absolute contraindication to tendon transfer is a lack of
appropriate donors.
The availability of muscle-tendon units with less than grade 5 strength is a
relative contraindication.
Similarly, if only muscles that have been denervated and then re-
innervated are available, this is also a relative contraindication.
Transfers planned in individuals with progressive neuromuscular diseases
should be carefully considered before proceeding because the underlying
disease process may affect the transferred unit.
Lastly, satisfactory results are difficult to achieve in transfers performed to
produce motion in less-than-supple joints
