Complicated by Peripheral Nerve Injury Abstract Closed fractures may be complicated by associated peripheral nerve injury.. Incidence The overall incidence of peripheral nerve injuries a
Trang 1Complicated by Peripheral Nerve Injury
Abstract
Closed fractures may be complicated by associated peripheral nerve injury However, because clinical information is limited,
determining the best course of treatment is difficult Most patients with closed fractures have a local nerve injury without nerve division; their prognosis for recovery is favorable In the acute setting, immediate surgery is usually unwarranted because of the difficulty in accurately defining the severity and extent of nerve injury When débridement of an open fracture or repair is not required, peripheral nerve injuries are best observed and the extremity treated with splinting and exercise to prevent loss of joint motion Patients who fail to demonstrate signs of recovery
at 6 months, either clinically or with electrodiagnostic testing, should undergo exploration to maximize the likelihood for return
of function When, during exploration, the nerve is in continuity, intraoperative measurement of nerve action potentials should
be done Measuring nerve action potentials will determine whether nerve grafting, local neurolysis, or excision of the injured segment, accompanied by primary repair, is the most appropriate treatment
Although peripheral nerve inju-ries are associated with almost every type of fracture, little consen-sus exists on the best methods for evaluation and management of these injuries Few clinical studies demon-strate consistent results to guide treatment Further complicating treatment choice is the fact that many widely accepted strategies are poorly substantiated by the available literature A framework for the ap-propriate approach to these injuries should be based, whenever possible,
on current understanding of the pathophysiology and natural history
of peripheral nerve injuries
Incidence
The overall incidence of peripheral nerve injuries associated with closed fractures is difficult to discern be-cause of the lack of prospectively ac-quired data Noble et al1reported on
a prospectively collected database of 5,777 multiply injured patients treated at a large regional trauma center Patients were primarily young (mean age, 34.6 years) and male (83%) Most experienced high-energy trauma during motor vehicle accidents (51.6%) or motorcycle ac-cidents (9.9%) Humeral fractures were associated with radial nerve
in-L Randall Mohler, MD
Douglas P Hanel, MD
Dr Mohler is Fellow, Section of Hand
and Microvascular Surgery, Department
of Orthopaedics and Sports Medicine,
University of Washington, Seattle, WA.
Dr Hanel is Professor, Section of Hand
and Microvascular Surgery, Department
of Orthopaedics and Sports Medicine,
University of Washington, Seattle.
None of the following authors or the
departments with which they are
affiliated has received anything of value
from or owns stock in a commercial
company or institution related directly or
indirectly to the subject of this article:
Dr Mohler and Dr Hanel.
Reprint requests: Dr Hanel, Department
of Orthopaedics and Sports Medicine,
University of Washington, Box 359798,
325 Ninth Avenue, Seattle, WA
98104-2499.
J Am Acad Orthop Surg 2006;14:
32-37
Copyright 2006 by the American
Academy of Orthopaedic Surgeons.
Trang 2jury in 9.5% of cases, with ulnar
nerve injury in 3.8%, and with
medi-an nerve injury in 1.4% Fractures of
the radius and ulna were associated
with ulnar nerve injury in 2.4% of
cases and with median nerve injury
in 1.3% Pelvic fractures were
asso-ciated with sciatic nerve injury in
1.1% of cases and with femoral
nerve injury in 0.16% Femoral
frac-tures were associated with sciatic
nerve injury in 1.1% of cases Tibial
and fibular fractures were associated
with peroneal nerve injury in 2.2%
of cases and with tibial nerve injury
in 0.5% Overall, the radial nerve
was the most frequently injured
nerve; in the lower limb, the
perone-al nerve was most commonly
in-jured Not included in this series
were nerve root avulsions and
inju-ries to the brachial and lumbosacral
plexus (primarily the result of
trac-tion mechanisms) Because the
pa-tient population was not limited to
closed injuries, the finding of a
low-er incidence of plow-eriphlow-eral nlow-erve
inju-ry in this group was expected.1
Generally, there is a higher
inci-dence of peripheral nerve injuries
as-sociated with fractures in the upper
extremity than with fractures in the
lower extremity In a prospective
clinical study of 101 patients who
sustained shoulder dislocations and
humeral neck fractures, 45% had
evidence of peripheral nerve injury
on physical examination, confirmed
by electrodiagnostic study.2The
ax-illary nerve was most commonly
in-jured (37%), followed by the
su-prascapular (29%), radial (22%),
musculocutaneous (19%), and ulnar
(8%) nerves Nerve injury was more
frequent in patients aged≥65 years
(54%) than in those aged <65 years
(26%) Fifty-seven patients had
hu-meral neck fractures, but this group
was not assessed independently of
those with concomitant
disloca-tions
The radial nerve is the most
com-monly injured nerve in association
with fractures of the humerus
Frac-tures of the middle and distal thirds
of the humerus are particularly apt
to have accompanying nerve damage because this is where the radial nerve is in closest contact with the bone.3-8Although the radial, or mus-culospiral, groove of the humerus is frequently described as containing the radial nerve and deep brachial ar-tery, this groove is actually the ori-gin of the brachialis muscle The ra-dial nerve is separated proximally from the humerus by fibers of the medial head of the triceps and of the brachialis Only as the nerve ap-proaches the lateral supracondylar ridge is it in direct contact with the humerus.9
Supracondylar humerus fractures
in skeletally immature patients also are frequently associated with neu-rologic complications Any of the three major nerves of the forearm may be involved In a review of 162 displaced supracondylar fractures in children, traumatic injury to the ra-dial nerve occurred in 7% of cases, median nerve injury in 3%, and ul-nar nerve injury in 1%.10Two retro-spective reviews11,12noted a high in-cidence of isolated injury to the anterior interosseous branch of the median nerve with supracondylar humerus fractures in children
Cramer et al11noted that in a cohort
of 101 pediatric supracondylar frac-tures, 12 of the 15 patients with identifiable nerve involvement had involvement of the anterior in-terosseous nerve Similarly, Dor-mans et al12found that among 200 pediatric patients treated for supra-condylar humerus fractures, 19 had associated nerve injuries: seven in-volved the anterior interosseous branch of the median nerve alone, and four were complete median nerve lesions Five radial nerve and three ulnar lesions were also identi-fied In two other studies, Brown and Zinar13and Mehlman et al14
report-ed on the iatrogenic complications
of treating pediatric supracondylar humerus fractures These studies dicate that the ulnar nerve was
in-jured, albeit transiently, in 2% of pa-tients
Natural History
Most reports of peripheral nerve in-jury associated with closed fracture suggest that nonsurgical treatment leads to recovery of nerve function in nearly all patients In a prospective clinical and electrodiagnostic study
of nerve injuries associated with shoulder dislocations and humeral neck fractures, de Laat et al2found that 82% of 45 patients with neuro-logic injury recovered well within 4 months Pollock et al4reviewed the data of 23 patients with radial nerve injury associated with closed hu-meral shaft fractures, all treated with closed management Complete spon-taneous recovery of radial nerve function occurred in all but one pa-tient (96%) The papa-tient without spontaneous return of function at 3 months underwent electrodiagnostic testing, which showed evidence of distal denervation Exploration 14 weeks after injury revealed that the nerve was trapped in the callus of the healed fracture Neurolysis provided
a complete recovery 8 months later Brown and Zinar13identified 23 neural injuries among 162 displaced supracondylar fractures in children Eighteen patients sustained the nerve deficits at the time of injury; there were twelve radial, six ulnar, and five median neuropathies An additional five nerve injuries were iatrogenic: four ulnar nerve injuries and one radial nerve injury All of the deficits resolved spontaneously
in 2 to 6 months (mean, 2.3 months)
In two other studies dealing with pe-diatric supracondylar humerus frac-tures, McGraw et al10and Cramer et
al11followed 138 and 101 patients, respectively They identified a 12%
to 15% incidence of injury, with complete recovery in all but one pa-tient in each series Recovery oc-curred as late as 9 months after in-jury
Trang 3Results of Treatment
The role and timing of surgical
ex-ploration are controversial aspects
of managing these nerve injuries
No prospective or comparative
stud-ies exist to help delineate the
appro-priate method of treatment
How-ever, Sonneveld et al6 reviewed 17
cases of humeral fracture associated
with radial nerve paralysis, 16 of
which were closed The radial nerve
was explored acutely in the 14
frac-tures that were treated surgically
Thirteen of these nerves appeared to
be undamaged; the remaining nerve
was contused and showed division
of a small number of fibers Clinical
recovery was complete in 12 of the
14 patients (including the patient
with gross nerve damage) and
in-complete in the remaining two
pa-tients One of the radial nerves that
on initial inspection appeared to be
uninjured failed to show any
evi-dence of clinical recovery During
re-exploration 8 months after injury,
the nerve was found trapped in the
intermuscular septum; the nerve
was freed, and complete recovery
was noted 3 years after injury As
noted previously, in 14 of the 17
ra-dial nerve injuries explored,6the
re-maining three were treated
nonsur-gically, and all three experienced
complete nerve recovery The
au-thors concluded that routine
explo-ration was not warranted
Similarly, Böstman and
col-leagues7,8examined 75 patients with
radial nerve palsy complicating a
fracture of the humeral shaft: 59
with immediate palsy (occurring at
the time of injury) and 16 with
sec-ondary palsy (occurring as a result of
fracture manipulation) No
distinc-tion was made between closed and
open injuries Early nerve
explora-tion and internal fracture fixaexplora-tion
(within 3 weeks) was performed in
37 patients (27 immediate and 10
secondary palsies) Thirty-eight
pa-tients (32 immediate and 6
second-ary palsies) were treated with initial
observation alone Of the latter
group, 26 patients experienced spon-taneous recovery and were not ex-plored; the remaining 12 patients who failed to show early spontane-ous recovery underwent delayed ex-ploration (at an average of 17 weeks postinjury) Because the patients treated with early exploration neces-sarily included a certain number of patients who would have recovered spontaneously, the authors com-pared the final outcome of those who underwent early exploration with the outcome of those initially treated expectantly Complete re-covery was documented in 73% of patients who underwent early explo-ration and in 87% of the group
treat-ed with initial expectance (including
12 of 38 with late exploration) Al-though the more severe fractures in this study may have prompted early exploration, it is also possible that some nerves potentially able to re-cover spontaneously were addition-ally damaged during exploration
Böstman and colleagues7,8concluded that routine early exploration could not be supported, suggesting that the choice between open and closed treatment is dictated by the nature
of the fracture and not by the func-tion of the nerve A recent study by Ring et al15reinforces these conclu-sions
In any series of humeral fractures,
a subset of patients has normal
radi-al nerve function following fracture but subsequently develops radial nerve palsy during closed treatment
Even surgeons who advocate obser-vation of primary radial nerve palsy have recommended early explora-tion in these instances of secondary peripheral nerve injuries.5Shah and Bhatti5 identified 16 patients with humeral fractures who developed secondary paralysis during closed treatment Eight patients were
treat-ed clostreat-ed, and eight underwent sur-gical exploration In all cases, the nerve was found to be intact, and each of the16 patients had complete neurologic recovery Because of the small number of patients in this
se-ries, definitive conclusions cannot
be drawn; nevertheless, results sug-gest that even with this clinical sce-nario, aggressive early exploration may not yield improved results Most large series of peripheral nerve repairs have been performed during times of war A recent pro-spective evaluation of factors influ-encing outcome was done in 490 pa-tients with complete peripheral nerve disruptions caused by projec-tile injuries during the Yugoslav
civ-il war.16All repairs were performed
in a single treatment center, and fi-nal outcome assessment, including motor function, sensory function, electrodiagnostic testing, and pa-tients’ subjective evaluation of the quality of recovery, was measured 24
to 30 months postoperatively Out-come was correlated with regenera-tive potential of the damaged nerve, level of the nerve injury, surgical technique (ie, direct suture, nerve graft, or denatured muscle graft), lo-cal nutritive state, length of nerve defect, duration of interval from in-jury to repair, and patient age Inter-estingly, certain nerves appeared to have greater “regenerative poten-tial,”16which seemed to be the fac-tor that most strongly affected out-come Radial, musculocutaneous, and femoral nerves had the best po-tential for recovery of function; me-dian, ulnar, and tibial nerves had only moderate potential; and the peroneal nerve had poor potential for recovery Although outcome was better in the more distal nerve inju-ries, the level of injury significantly
(P < 0.001) affected outcome only for
nerves with moderate regenerative potential (ie, median, ulnar, and tib-ial nerves) Similarly, the length of the nerve defect did not
significant-ly influence outcome for nerves with the best potential for recovery (ie, musculocutaneous and femoral) For other, less resilient nerves, however,
a linear relationship did exist be-tween the length of the defect and repair results Final outcome was not affected by the state of local
Trang 4blood supply (vascularized
soft-tissue bed) and scar soft-tissue, by the
ap-plied surgical technique, or by
pa-tient age This latter finding is
probably reflective of the limited
number of children in this study
population
Of the variables discussed, only
time from injury to repair was
mark-edly affected by the surgeon,
indicat-ing that a balance must be struck
when treating closed nerve injuries
During active observation to allow
spontaneous recovery of less severe
injuries, the surgeon must avoid
in-troducing a delay that impairs the
outcome of patients who would
ulti-mately benefit from surgery
Roga-novic16 noted a linear correlation
between repair outcome and
pre-operative interval According to this
study, the best probability for
suc-cessful median, ulnar, or tibial nerve
repair exists when the preoperative
interval occurs in fewer than 3
months In cases of radial nerve
inju-ry, patients had an excellent chance
for success when surgery was
per-formed within 15.6 months of
inju-ry For most nerves, the interval after
which repair appeared to be useless
was between 9 and 12 months
How-ever, for the radial nerve, such an
in-terval ceiling did not exist
Approach to Treatment
With an approximate 85%
spontane-ous recovery rate,7,8peripheral nerve
injuries associated with closed
frac-tures probably are best followed
ex-pectantly These injuries should not
be considered either an indication or
a contraindication for open
reduc-tion and internal fixareduc-tion (Figure 1)
Skeletal injury is managed at the
dis-cretion of the surgeon In cases
re-quiring internal fixation, whether by
plates and screws or by
intramedul-lary devices, the extent of
explora-tion should be limited to that
neces-sary to ensure that the nerve is free
of the fracture site For example, in
closed humeral fractures treated
with intramedullary fixation, the
fracture is exposed through a small incision, and soft tissues are mobi-lized away from the bone ends
Guidewires are passed from one frac-ture fragment to the other under di-rect visualization, and the fracture is reduced without specifically looking for the nerve No published study to date reports a nerve lesion occurring
“away” from the closed fracture site
Thus, the extent of dissection is dic-tated by fracture type, with the only
indication for extensive nerve dis-section being rare cases in which a transected nerve is identified and mobilization facilitates the nerve re-pair
During the wait for spontaneous nerve recovery, joint splinting and range-of-motion exercises should be initiated as soon as fracture care al-lows, thereby minimizing stiffness and joint or muscle contracture Most patients who recover
sponta-Figure 1
Treatment algorithm for closed fracture with associated nerve injury
Trang 5neously begin to do so in the first
few months For those who do not,
electrodiagnostic studies—obtained
at 6 and 12 weeks—are a helpful
ad-junct.5,17,18 The studies done at 6
weeks serve as a baseline for
re-examination and document the
se-verity of neurologic injury A typical
finding is the identification of
fibril-lation potentials, positive sharp
waves, and monophasic action
po-tentials of short duration
Repeat electrodiagnostic testing
of patients that does not
demon-strate clinical recovery at 12 weeks
will likely identify two subsets of
pa-tients One group will demonstrate
improved nerve function with larger
polyphasic motor unit action
poten-tials of longer duration compared
with those in the 6-week study This
is evidence that some degree of
spon-taneous recovery may be expected
The degree to which the recovery
will occur is not predictable In cases
in which the recovery is limited,
ten-don transfers are required to improve
function The timing of these
trans-fers is not well defined Although
in-jured nerves recover over 24 to 36
months, the degree of functional
re-covery is well established within 18
months of injury
The second group will show few
signs of recovery, with fibrillation
potentials, positive sharp waves, and
diminished or absent small motor
unit potentials remaining the
domi-nant features of the study This
sec-ond group is further divided into
three subgroups: children showing
little evidence of recovery, adults
with radial nerve deficits, and adults
with injuries other than of the
radi-al nerve Children, defined by
skele-tal immaturity, should be observed
for a total of 9 months before
explo-ration or reconstruction because of
the reported 95% rate of recovery
within this timeframe.5,10-12 Those
children who do not recover are
treated with tendon transfers
Adults with radial nerve palsies
may be expected to recover within 6
months in >90% of cases For adults
who do not recover, the authors of two studies16,19propose that explora-tion and repair remains a viable op-tion for up to 6 months after injury
This point remains controversial, however, and the general opinion, although undocumented, is that in-stead of exploring the nerve, sur-geons should consider tendon trans-fers for radial nerve palsies rather than nerve repair The rationale is that tendon transfers in this setting provide equal or better functional re-covery than do radial nerve repairs performed 6 months postinjury
Patients in the third subgroup include adults with nerve injuries other than of the radial nerve As mentioned, Roganovic16 demon-strated that certain nerves have bet-ter recovery potential that others
For instance, the femoral and mus-culocutaneous nerves demonstrate excellent recovery potential when repaired within 24 weeks of injury, whereas the median, ulnar, and tib-ial nerves demonstrate moderate re-covery when repaired within the same timeframe; all five nerves demonstrate very little recovery when repaired later than 24 weeks
The peroneal nerve has very little re-covery potential no matter when it
is explored or repaired
Early exploration presents a co-nundrum: the likelihood of finding a repairable lesion in the setting of closed fractures is unlikely,
especial-ly in the lower extremities, while the likelihood of notable recovery, should a repairable lesion be found,
is markedly diminished when repair
is delayed >4 months.16 In other words, the delayed exploration may
be unnecessary With this in mind, the surgeon is likely to discover a nerve in anatomic, but not physio-logic, continuity; he or she is then faced with the difficult decision of choosing between neurolysis, exci-sion and repair, or doing no more than ensuring that there are no com-pressing fascial bands or bony frag-ments, or a fracture callus, along the course of the nerve Physical
conti-nuity does not ensure spontaneous recovery, nor does complete loss of distal function preclude spontane-ous recovery
Intraoperative nerve stimulation may assist with these decisions The intraoperative technique of Kline and Happel,20of stimulating the in-volved nerve proximally and record-ing the nerve action potential distal
to the injured segment, is useful in this difficult situation They found that, for patients in whom only neu-rolysis was performed, good func-tional recovery occurred in 93% of nerves that had a recordable nerve action potential distal to the lesion When resection of the injured seg-ment was based on the absence of a recordable nerve action potential distal to the lesion, histologic exam-ination uniformly confirmed a le-sion with poor potential for useful recovery without repair
These studies are not simply the application of a nerve stimulator proximal to a zone of injury, delivery
of an electrical stimulus, and obser-vation of a twitching muscle distally Little information is gained from this technique, especially when there is
no distal response Intraoperative nerve evaluation is the montage of in-formation gained from somato-sensory evoked potentials, elec-tromyography, and nerve conduction velocity studies Obtaining this infor-mation is technically demanding and requires intraoperative collaboration with a trusted neurophysiologist-electrodiagnostician.20,21The mechan-ics of this diagnostic technique con-sist of placing recording electrodes proximally (at the mastoid, seventh cervical region, and contralateral scalp), exposing the injured nerve, and stimulating throughout the zone of injury Hook electrodes are placed proximal to the zone of injury and the effects of stimulation recorded prox-imally The electrodes are advanced
at 1-cm increments, and the stimu-lation response is measured The point at which there is loss of soma-tosensory evoked potential response
Trang 6designates the transition between
functioning and nonfunctioning
nerves
In further studies, stimulating the
nerve at a constant point
proximal-ly and measuring the response at
1-cm increments allows recording of
nerve compound action potentials
The presence of nerve compound
ac-tion potentials resulting from
in-trafield stimulation demonstrates
regenerating nerve fibers, which are
an indication that further recovery
will occur and that intraneural
dis-section should be limited Similarly,
by placing an electrode in a target
muscle and stimulating the injured
nerve motor, compound action
po-tentials reflect the response of a large
group of motor units, also a positive
finding Nerve conduction velocities
are measured across the zone of
inju-ry and specific areas of slowing are
noted
The intraoperative interpretation
of this information requires
peri-operative coordination, a dialogue
between the neurophysiologist and
the surgeon, and a clearly defined set
of goals for dealing with the
infor-mation provided Most importantly,
these studies require time and a
pa-tient surgeon who is willing to listen
to the recommendations of, and
re-peat the studies requested by, the
electrodiagnostician This
coordinat-ed effort, however, can at times
pro-vide equivocal data In such cases,
the surgeon must make the difficult
decision of resection and grafting or
of leaving the neuroma in situ In
most equivocal cases, we leave the
nerve intact, choosing further
obser-vation and appropriate tendon
trans-fers when the nerve fails to recover
Summary
Closed fractures are occasionally
complicated by peripheral nerve
in-jury The number of cases is limited
and incidence is sporadic, making
longitudinal research difficult Most
patients recover without surgery
Those who fail to show signs of re-covery at 6 months, either clinically
or with electrodiagnotic testing, should undergo exploration Base-line electrodiagnostic studies are made 6 weeks postinjury; when there is no sign of nerve recovery, studies are repeated at 12 weeks
Adults who show evidence of recov-ery should continue to be observed
Adults without evidence of recovery and with radial nerve injury should undergo repeat nerve studies and ul-timately, if necessary, exploration, repair, and/or tendon transfers The same procedure should be followed
in adults with injuries other than those of the radial nerve Exploration
in skeletally immature children, whether exhibiting evidence of re-covery or not, should be delayed for
9 months
References
1 Noble J, Munro CA, Prasad VS, Midha R: Analysis of upper and lower ex-tremity peripheral nerve injuries in a population of patients with multiple
injuries J Trauma 1998;45:116-122.
2 de Laat EA, Visser CP, Coene LN, Pahlplatz PV, Tavy DL: Nerve lesions
in primary shoulder dislocations and humeral neck fractures: A prospective
clinical and EMG study J Bone Joint
Surg Br1994;76:381-383.
3 Postacchini F, Morace GB: Fractures
of the humerus associated with
paral-ysis of the radial nerve Ital J Orthop
Traumatol1988;14:455-464.
4 Pollock FH, Drake D, Bovill EG, Day
L, Trafton PG: Treatment of radial neuropathy associated with fractures
of the humerus J Bone Joint Surg Am
1981;63:239-243.
5 Shah JJ, Bhatti NA: Radial nerve paral-ysis associated with fractures of the
humerus: A review of 62 cases Clin
Orthop Relat Res1983;172:171-176.
6 Sonneveld GJ, Patka P, van Mourik
JC, Broere G: Treatment of fractures of the shaft of the humerus accompanied
by paralysis of the radial nerve.
Injury1987;18:404-406.
7 Böstman O, Bakalim G, Vainionpaa S, Wilppula E, Patiala H, Rokkanen P:
Radial palsy in shaft fracture of the
humerus Acta Orthop Scand 1986;
57:316-319.
8 Böstman O, Bakalim G, Vainionpaa S, Wilppula E, Patiala H, Rokkanen P: Immediate radial nerve palsy compli-cating fracture of the shaft of the hu-merus: When is early exploration
jus-tified? Injury 1985;16:499-502.
9 Whitson RO: Relation of the radial nerve to the shaft of the humerus.
J Bone Joint Surg Am1954;36:85-88.
10 McGraw JJ, Akbarnia BA, Hanel DP, Keppler L, Burdge RE: Neurological complications resulting from supra-condylar fractures of the humerus in
children J Pediatr Orthop 1986;6:
647-650.
11 Cramer KE, Green NE, Devito DP: In-cidence of anterior interosseous nerve palsy in supracondylar humerus
frac-tures in children J Pediatr Orthop
1993;13:502-505.
12 Dormans JP, Squillante R, Sharf H: Acute neurovascular complications with supracondylar humerus
frac-tures in children J Hand Surg [Am]
1995;20:1-4.
13 Brown IC, Zinar DM: Traumatic and iatrogenic neurological complica-tions after supracondylar humerus fractures in children. J Pediatr Orthop1995;15:440-443.
14 Mehlman CT, Strub WM, Roy DR,
Wall EJ, Crawford AH: The effect of surgical timing on the perioperative complications of treatment of supra-condylar humeral fractures in
chil-dren J Bone Joint Surg Am 2001;83:
323-327.
15 Ring D, Chin K, Jupiter JB: Radial
nerve palsy associated with high-energy humeral shaft fractures.
J Hand Surg [Am]2004;29:144-147.
16 Roganovic Z: Factors influencing the
outcome of nerve repair Vojnosanit
Pregl1998;55:119-131.
17 Robinson LR: Traumatic injury to
pe-ripheral nerves Muscle Nerve 2000;
23:863-873.
18 Robinson LR: Role of
neurophysiolog-ic evaluation in diagnosis J Am
Acad Orthop Surg2000;8:190-199.
19 Amillo S, Barrios RH, Martinez-Peric
R, Losada JI: Surgical treatment of the radial nerve lesions associated with
fractures of the humerus J Orthop
Trauma1993;7:211-215.
20 Kline DG, Happel LT: Penfield Lec-ture: A quarter century’s experience with intraoperative nerve action
po-tential recording Can J Neurol Sci
1993;20:3-10.
21 Slimp JC: Intraoperative monitoring
of nerve repairs Hand Clin 2000;16:
25-36.