Radial nerve injury is one of the most dreaded consequences of humerus fractures. Hence the approach to any case with potential of this sequalae needs to be approached in a calculated manner as explained in this case discussion and review of two recent jounral articles

1. Humerus shaft fracture
complicated by radial nerve
palsy: Is surgical exploration
necessary?
 PRESENTER : DR.ANMOL
MITTAL
 CHAIR PERSON-
DR.S.K.SAIDAPUR

2. ORIGINAL ARTICLE
 Musculoskelet Surg (2016) 100 (Suppl
1):S53–S60 DOI 10.1007/s12306-016-0414-3.
Department of Hand Surgery and
Microsurgery, University of Modena and
Reggio Emilia, Policlinico di Modena, Modena,
Italy
M. Rocchi1 • L. Tarallo1 • R. Mugnai1 • R.
Adani2

3. OBJECTIVE :
 To discuss an integrated management
strategy to determine the right treatment
approach to different kinds of humeral
fractures with complete sensory and motor
RNP.

4. MATERIALS AND METHODS :
 This was a meta analysis which included more
than 50 studies, both retrospective and
prospective, published over a period of 60
years.

5. INTRODUCTION :
 The overall incidence of radial nerve injury
after humeral shaft fractures is 11.8 %,
representing the most common peripheral
nerve injury associated with long bone
fractures.
 The high percentage of radial nerve injury
associated with bone fracture is attributable to
the intimate contact with the periosteum of the
humerus.

6.  In particular, the radial nerve was found to be
in direct contact with the posterior humerus
from 17.1 cm ± 1.6 to 10.9 cm ± 1.5 proximal
to the lateral epicondyle.
 Bono et al defined ‘‘danger zone’’ the point as
the nerve pierces the later intermuscular
septum, 12.3 cm ± 2.3 proximal to the
olecranon fossa, because the nerve had very
little mobility as it is interposed between the
obliquely oriented septum and the lateral
aspect of the humerus.

7.  Afterward, the radial nerve courses anterior to the
humerus at the level of the metaphyseal flare,
where it is separated from bone, by the brachialis
muscle.
 Hence, the radial nerve is at risk of lesion, in
particular, at 2 locations: the posterior mid-shaft,
where the nerve lies in contact with the humerus,
and at the distal lateral humerus as it pierces the
lateral intermuscular septum.

9. LEVEL OF FRACTURE INCIDENCE IN PERCENTAGE
PROXIMAL THIRD 3.4%
PROXIMAL AND MIDDLE THIRD
JUNCTION
10.5%
MIDDLE THIRD 21.9%
MIDDLE AND DISTAL THIRD
JUNCTION
20%
DISTAL THIRD 10.5%
The mechanisms of injury can be primary or
secondary:
PRIMARY: The loss of function occurs at the time
of injury. Contributes 80-90% cases.
SECONDARY: The loss of function occurs during
the course of treatment, corresponding to 10–20 %
of the cases.

10.  Holstein and Lewis affirm that radial nerve
palsies are associated most commonly with
spiral fracture followed by transverse, oblique
and comminuted.
 Iatrogenic palsy, occurs due to direct trauma of
surgical instruments, chronic impingement
between internal fixation and the nerve, or
manipulation of closed reductions by
intramedullary nailing.

11.  The difference in the rate of recovery between
primary and secondary palsies was not
significant. The overall rate of recovery was
88.1 %, with spontaneous recovery reaching
70.7 % in patients treated conservatively.
 The difference in rates of recovery between
complete (77.6 %) and incomplete (98.2 %)
fractures and those which are closed (97.1 %)
or open (85.7 %) were all statistically
significant.

12. DIAGNOSIS:
 Radial nerve palsies can be classified as
either partial or complete.
 Radial nerve sensation to light touch and
pinprick can be tested in the dorsal radial
aspect of the hand toward the thumb/index
web space. Tinel’s sign can be helpful in
indicating the progression of nerve recovery.

13.  If the brachioradialis or extensor carpi radialis
longus (ECRL) is not functioning, the injury
should be at the level of the humeral shaft.
 If the lesion is distal to the origin of the
posterior interosseus nerve, ECRL function will
be intact and the wrist will be pulled into radial
deviation with attempts at extension.

14.  Neurophysiologic tests, electromyography, and
nerve conduction velocity, are useless in the initial
management of patients with a RNP.
 These tests, however, after 3–4 weeks, may help
to determine the level and extent of the radial
nerve damage, to individuate a baseline of
function, and to monitor recovery, which may
occur before clinical sign.
 If the patient has radial nerve exploration and
reconstruction, an electromyogram also may be
used to follow recovery of the nerve in the
postoperative period.

15. TREATMENT OPTIONS
 CLINICAL OBSERVATION
 EARLY EXPLORATION

16. CLINICAL OBSERVATION
 The supporters of expectant management claim
that spontaneous recovery in closed humeral
shaft fractures with complete motor and sensory
radial nerve injury is reported to occur in 73–
92% of patients.
 According to the literature, most cases of RNP
are caused by a contusion injury, while
transection of the nerve is found only in 12 % of
the patients with irreversible nerve palsy.

17.  The advantages are the avoiding of
intraoperative risks, including wound infection
and osteomyelitis, the avoiding of nerve
devascularization, and the conservation of a
natural environment for easier exploration in
case of permanence of injury.
 Postponing surgery may allow the neurilemmal
sheath to thicken, which facilitates repair if
neurorrhaphy is needed.
 The potential disadvantages are the possibility
that fibrosis makes more difficult the surgical
exploration.

18.  During recovery, early range of motion exercises
and dynamic splinting of the wrist, thumb, and
fingers are important to help prevent joint
contractures. Limb edema is common and must
be minimized with a compressive garment,
elevation, and range of motion exercises.
 A first neurophysiologic testing should be
performed at minimum 25 days after the injury
[25, 26]. This study may demonstrate ‘‘fibrillation
potentials, positive sharp waves, and mono-
phasic action potentials of short duration’’.

19.  another electrodiagnostic study may serve as
an adjunct study for those lacking nerve
recovery at the 6 weeks of follow-up.
 The brachioradialis and extensor carpi radialis
longus are the first muscles to be reinnervated,
and the extensor indicis is the last muscle to
recover.
 Complete recovery typically occurs within 6–
12 months, because axons can regenerate
with a maximum speed of 1.7 mm per day
distally to the site of injury.

20.  If a follow-up electrodiagnostic study at the 12-
week point shows similar findings as the
baseline, then exploration may be indicated.
 Although widely debated, many authors
consider 4–6 months to be an appropriate
length of time for expectant management.

21. EARLY EXPLORATION
 Recommended in several cases such as:
1. Open fracture that requires debridement and
stabilization.
2. Irreducible fracture or unacceptable reduction.
3. Associated vascular or severe soft tissue injury.
4. Radial nerve deficit after manipulation.
5. Intractable neurogenic pain suggesting nerve
entrapment or compression
6. High-velocity gunshot wounds, sharp or
penetrating injury, post injection palsy.
7. High suspicion of nerve laceration with spiral
oblique fractures such as Holstein-Lewis fracture.

22.  During surgery, complex injury patterns should
be managed in the following order:
fracture
stabilization
definitive or
temporary
vascular repair
nerve repair.

23.  The most common procedure for stabilization of
the humerus is compression plate and screws.
 The risk of radial nerve injury during this
procedure is reported as 0–10 %.
 The incidence of radial nerve damage during
intramedullary nailing is reported between 0 & 5
%.
 However nailing is not recommended as the
nerve may be entrapped in the fracture.

24.  The advantages of early exploration of the
nerve, within 7–14 days from the trauma are:
1. More accurate determination of location and
extent of nerve damage.
2. Intraoperative measurement of action
potentials can be performed if the nerve is
found to be in continuity.

25.  Some surgeons suggest early exploration is
easier and safer, not only in the cases
mentioned above, but also in closed fractures
associated with nerve palsy as functional
nerve recovery is more complete and constant
with this approach.
 The persistence of palsy is a serious risk
because it could determine potential atrophy
and motor endplate loss that could
compromise nerve recovery on late
exploration and significant loss of function.

26.  Early exploration and repair can facilitate better
characterization of the nerve injury, quicker nerve
recovery and return to function. Moreover, after
fracture fixation and stabilization is achieved, a
neurolysed or repaired nerve will potentially
benefit from a better environment for recovery
with less tension, motion, or callus formation to
impede nerve healing.
 The potential disadvantage is over treatment of a
lesion that recovers spontaneously in 73–92 % of
the cases.

27. SURGICAL APPROACH
 Surgical intervention for radial nerve injury based on
location and the time of nerve injury can be classified
into neurorrhaphy, nerve grafting, nerve transfers and
tendon transfers.
 If transection of the radial nerve is found during
immediate surgical exploration, a primary nerve
repair is indicated.
 Nerve grafting is preferred in cases of tension at the
neurorrhaphy site or if there is a large nerve gap that
has to be bridged. Factors that influence the outcome
after grafting include the length of the defect that
should be bridged and the denervation time.

28.  Indications for a tendon transfer include
1. No sign of nerve recovery at 1 year
2. Incomplete recovery
3. Failed nerve reconstruction
 The patient’s level of function, anatomy, and
level of radial nerve injury are three factors
routinely used to decide on the appropriate
tendons to use for transfer.
 Wrist extension is achieved with transfer of
pronator teres into extensor carpi radialis brevis,
whereas for finger extension, the flexor carpi
radialis is usually used.

29. CONCLUSION:
 Through their literature review, they wanted to
provide a simple and clear algorithm of treatment
which describes the behavior in each different
situation.
 The surgeon has to consider first the type of
fracture and associated complications.
 Early exploration is indicated for conditions as
stated earlier. Surgical exploration could be initially
deferred for fracture with low risk of radial nerve
injury.
 The nerve palsy has to be followed up by
neurophysiologic and clinic tests at least at 3

30.  If there are no electrophysiological changes at
6–12 weeks, a surgical exploration is needed,
although we could continue clinical
observation until 5 months because of poor
functional results of late surgical exploration
and repair over this time.
 During open reduction one must consider the
risk of secondary palsy: Intramedullary nail is
not recommended.

31. ORIGINAL ARTICLE
 Department of Orthopaedic Surgery, Hospital
for Special Surgery, New York, NY 10021,
USA; 2016;
 Department of Orthopaedic Surgery, University
of Ioannina School of Medicine, Ioannina, PC
45110, Greece; 2016
Anastasios V. Korompilias, Marios G.
Lykissas , Ioannis P. Kostas-Agnantis ,
Marios D. Vekris , Panayiotis N. Soucacos ,
Alexandros E. Beris

32. OBJECTIVE :
 To determine whether patients with complete
sensory and motor radial nerve palsy following
a closed fracture of the humeral shaft should
be surgically explored.
 The timing of surgical intervention was also
investigated.

33. INTRODUCTION :
 While recommendations for early exploration
and nerve repair in cases of open fractures of
the humeral shaft associated with radial nerve
palsy are clear, the therapeutic algorithm for
the management of closed humeral shaft
fractures complicated by radial nerve palsy is
still uncertain.
 The overall incidence of radial nerve injury
after humeral shaft fractures is 11.8%
representing the most common peripheral
nerve injury associated with long bone
fractures.

34.  Predisposing factors for such high incidence of
radial nerve involvement includea relatively
fixed position of the radial nerve and the direct
contact with the periosteum of the humerus as
it turns in the spiral groove and passes through
the lateral intermuscular septum of the arm.
 At this level the bone ends can easily entrap,
contuse, or even lacerate the radial nerve.

35.  Studies show that more than 80% the radial
nerves injured during closed humeral shaft
fractures recover function spontaneously.
 Although majority prefer conservative
management for the same, a new school of
thought suggests that exploration of the radial
nerve and open reduction of the humeral shaft
fracture, due to it being a technically easier and
safer procedure, reduces the risk of further neural
damage and the high frequency of nerve
entrapment after manipulation.

36. MATERIALS AND METHODS :
 This retrospective study involved 25
participants. (8 women, 17 men)
 All patients had unilateral fracture of the
humeral shaft, which involved the proximal
third in 2, the middle third in 10, and the distal
third of the humerus in 13 patients.
 8 fractures were transverse, 13 were spiral or
oblique, and 4 fractures were comminuted.
 20 fractures were following a high velocity
trauma and 5 following fall.

37.  Baseline electrophysiological studies (i.e.
nerve conduction velocity studies and
electromyography) were obtained 4–6 weeks
after injury and were repeated every 4 weeks
for the first 6 months.
 Surgical intervention was indicated if functional
recovery of the radial nerve was not present
after 16 weeks of expectant management.

38.  Using loopes magnification the radial nerve was
identified distally between the brachialis and the
brachioradialis muscles.
 A thorough exploration of the radial nerve at a
distance of 7– 10 cm above and below the
fracture was required in order to rule out
entrapment, contusion or laceration.
 Postoperative follow-up examination included
radiographic evaluation of the fracture, physical
examination (i.e. Tinel’s sign), and monthly
electrophysiological studies for motor and
sensory nerve recovery.

39. Inclusion criteria:
The inclusion criteria for this retrospective study
were:
(1) closed fractures of the diaphyseal
humerus;
(2) complete motor and sensory radial nerve
injury;
(3) age 16 years at least at the time of injury;
and
(4) follow-up time of at least 2 years.

40. RESULTS:
 Surgical exploration, nerve repair or
reconstruction, was performed in 12 patients
(48%) with unrecovered radial nerve palsy
after a mean period of expectant management
of 16.8 weeks (range: 16–18 weeks).
 In 2 of them (10%) total nerve transection was
found. Both these patients sustained high-
energy trauma

41.  Interposition nerve grafting was performed
using nerve grafts from the sural nerve.
 Transfer of pronator teres into extensor carpi
radialis brevis, palmaris longus into extensor
policis longus, and flexor carpi radialis into
extensor digitorum muscle was done
simultaneously.
 At the last follow-up, 4 and 6 years after
surgery, functional recovery of the radial nerve
was absent in both of them. However, at this
time, sufficient extension of the wrist and
fingers reconstructed with tendon transfers

42.  In 10 patients the radial nerve was found to be
macroscopically intact during surgical
exploration
 Two of the intact nerves were entrapped
between the bone ends. In these 2 cases
surgical release was performed.
 In 2 other patients contusion of the radial
nerve at the level of the humeral fracture with
perineurial adhesions in a small segment of
the nerve was detected. In these cases
external neurolysis was the treatment of
choice.
 All intact nerves fully recovered after a mean

43.  Surgical exploration was not performed in 13
patients (52%).
 In these patients, repeated clinical
examination and electrodiagnostic studies
demonstrated initial signs of nerve recovery
almost simultaneously. The mean time to full
nerve recovery was 12 weeks (range: 7–14
weeks).
 Uncomplicated humeral fracture healing was
obtained in all patients except 1 treated with
open reduction and fixation with plate and
screws. The mean time for fracture healing
was 11.8 weeks after surgery.

44. DISCUSSION:
 As has been frequently reported,
pathoanatomically, the radial nerve is at greater
risk for injury along the distal third of the
humerus due to the absence of interposed
muscle protection.
 This was in accordance with the assumption of
the Holstein–Lewis fracture pattern in which
laceration of the nerve occurs between the
bone fragments of a 1 spiral fracture at the
distal third of the humerus.

45.  Recent evidence suggests that the middle and
middle-distal fractures are most commonly
associated with this type of lesion.
 This can be attributed to the tight bound of the
nerve as it pierces the lateral intermuscular
septum 10 cm above the lateral epicondyle.
 Studies have demonstrated that radial nerve
injuries are associated most commonly with
transverse and spiral fractures than oblique and
comminuted fractures.
 Relation to open or closed fractures has been
found to be statistically insignificant.

46.  When open reduction and internal fixation is
chosen for a patient with preoperative radial
nerve palsy, compression plating is the
treatment of choice, allowing simultaneous
anatomic reduction of the fracture and
accurate determination of the extent and the
type of radial nerve lesion.
 In a patient with severe open fracture of the
humerus associated with preoperative radial
nerve palsy external fixation is recommended.

47.  Nerve conduction velocity studies and
electromyography determine the location and
extent of nerve damage.
 Electromyography is also helpful in monitoring
radial nerve recovery.
 Usually, 3–5 weeks are required for pathologic
potentials to manifest.
 Degeneration of the motor endplate and
irreversible muscle atrophy occurs if sufficient
reinnervation is not present within 12–18
months after injury.

48.  Experimental studies have demonstrated poor
functional recovery when nerve repair is delayed for
3 months due to decreased motor neuron
regeneration capacity.
 In a rat model, it has been shown that this can be
attributed to Schwann cells, which play an important
role in nerve regeneration after peripheral nerve
injury through production and excretion of various
proteins, such as neurotrophic factors.
 More specifically, Schwann cell ability to respond to
signals of axonal degeneration following peripheral
nerve injury is significantly reduced after 2 months of

49. Conclusion:
 Radial nerve palsy following humeral shaft fractures
usually involves a contusion or a mild stretch.
 Due to high rate of spontaneous recovery a policy of
expectancy is recommended.
 Having in mind the different personality of humeral
shaft fractures, each of them should be approached
individually.
 If the humeral fracture is open, surgical exploration,
repair or reconstruction is indicated. in cases of closed
fractures associated with radial nerve injury 16–18
weeks of expectant management followed by surgical
intervention is the treatment of choice.
 Simultaneous tendon transfer at the time of nerve
reconstruction or repair can be beneficial.

50. IN A NUTSHELL
(1) Delaying the surgery for more than 5 months is
associated with poor results.
(2) There is no proven benefit of waiting for
spontaneous recovery beyond 7 months.
(3) There is a high rate of spontaneous functional
recovery, which in this study was found in all
patients treated conservatively and in 83% (10 out
of 12) of patients underwent surgical exploration.
(4) The maximum time to full nerve recovery for
patients nonsurgically treated was 15 weeks in this
series.

51. (5) The recovery time after a high energy closed
humeral shaft fracture can be prolonged, this article
recommends 16–18 weeks of expectant
management. Nerve repair should be performed
after this time period and no later than 7 months
after injury.
(6) During surgical exploration adequate resection of
surrounding scar tissue and neuromas should be
performed.
(7)Nerve grafting is preferred in cases of tension at
the neurorrhaphy site or if there is a large nerve gap
that has to be bridged. Results after nerve grafting
are reported to be comparable with primary nerve
repair.

52. (8) For patients without functional reinnervation
after primary nerve repair or nerve grafting,
tendon transfers are indicated.
(9) This article recommends simultaneous
tendon transfer at the time of nerve
reconstruction or repair. Wrist extension is
achieved with transfer of pronator teres into
extensor carpi radialis brevis, whereas for finger
extension the flexor carpi radialis is usually
used.

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