Keywords
brachial plexus - birth injury - microsurgery - glenohumeral dysplasia
In this article, we describe our personal experience in the management of children
with brachial plexus birth injury (BPBI). The first formal brachial plexus clinic
was established at the Sick Kids Hospital in the 1980s, under the direction of Dr.
Howard Clarke and Dr. Ronald Zuker. At the outset, it was established as a multidisciplinary
clinic. Soon after its creation, Dr. Howard Clarke assumed the main leadership of
this clinic and has gone on to train several generations of pediatric plastic surgeons
within Canada and internationally. Our current team of brachial plexus surgeons consists
of Dr. Clarke (plastic surgery), Dr. Davidge (plastic surgery), and Dr. Hopyan (orthopaedic
surgery).
The global literature on BPBI is very rich, displaying varied but overlapping approaches
to the primary and secondary management of infants and children with this condition.
We reference key articles in this manuscript, but also focus on certain aspects of
the clinic setup and our personal decision-making that are not readily found in other
published works. The experience we present here is based on the care of over 1,800
patients with BPBI over the last three decades. Our practice continues to evolve as
our understanding of BPBI and its treatment outcomes has matured.
Clinic Structure and Design
Clinic Structure and Design
This is an often overlooked aspect of BPBI management. Many of our fellows graduate
and go on to establish the first brachial plexus clinic at their hospital. The importance
of the setup and design of the clinic cannot be overemphasized to ensure long-lasting
success.
Personnel and Culture
A multidisciplinary team comprised of properly trained and experienced staff is the
foundation of a well-functioning brachial plexus clinic. Our clinic team is comprised
of plastic surgeons, orthopaedic surgeons, physiotherapists, occupational therapists,
nurses, social workers, psychologists, research support staff, and trainees. We place
a high importance on fostering a collegial and supportive culture so as to optimize
team dynamics, communication, and ultimately patient care. Ideally, all members of
the team are enthusiastic, committed, and engaged in working with children suffering
from brachial plexus injuries. Long-term stability of the team is especially beneficial
considering that most patients are followed for many years.
Physical Structure and Layout
Our primary clinical assessments are completed in a large clinic room with sufficient
space for families, patient assessment, and involvement of multiple team members and
learners. Educational and visual aid materials are available in the clinic room, which
are important to facilitate discussions with patients and families around diagnosis
and possible interventions.
Clinic Database
Development of a robust and well-curated clinic database is extremely valuable and
should be done from the outset. Although implementing and maintaining an accurate
database requires time and effort, its impact on the clinic can be significant. Our
clinic database has enabled the development of new and innovative tools for patient
assessment and evaluation (i.e., Active Movement Scale [AMS], Brachial Plexus Outcome
Measurement [BPOM]). Interrogation of the database further drives the evaluation and
modification of these tools.
Clinic Visibility/Awareness
To facilitate early patient referrals, general practitioners in the region must be
aware of the existence of the clinic. Beyond the pediatric hospital in which the clinic
exists, there must be an awareness among referring physicians, nurse practitioners,
midwives, and any other health care providers that are seeing infants. An easily accessible
central triage and referral process is important to ensure that all patients requiring
evaluation are seen in the clinic as early as possible postnatally. Perhaps most importantly,
giving the clinic the formal name of “Brachial Plexus Clinic” within the hospital
will facilitate this triage process.
Assessment of Infants with BPBI: Indications and Timing of Primary Nerve Surgery
Assessment of Infants with BPBI: Indications and Timing of Primary Nerve Surgery
Prior work by our group has demonstrated that a single age or criterion for primary
nerve surgery is insufficient to accurately predict who requires operative management.[1]
[2] Consequently, there are several time points within the first year of life where
we may recommend a primary nerve operation. Our algorithm has evolved over time,[3]
[4] with the most recent iteration demonstrated in [Fig. 1].
Fig. 1 Sick Kids algorithm for the management of infants with BPBI. This most recent modification
includes primary management of the shoulder in infants with glenohumeral dysplasia.
(Reproduced with permission from Zuo et al.[32])
Initial Intake Assessment (Prior to 3 Months of Age)
We are fortunate to have a robust referral system, whereby the majority of infants
with suspected BPBI are referred within the first week of life. These are triaged
to be seen first by the clinic physiotherapist for an initial evaluation at 2 to 3
weeks of age. The physiotherapist follows the infant serially until the first multidisciplinary
clinic with the surgeon at 3 months of age.
Early and serial assessments by physiotherapy serve several valuable purposes. First,
it enables an experienced team member to screen referrals and conduct an early assessment
of function. At the appointment, a full history and comprehensive physical examination
are completed. The examination involves assessment of passive range of motion (ROM)
and evaluation using the AMS.[5]
[6] Fracture callus can also be readily palpated at this age. This provides baseline
data and information, which is helpful for instructing future clinic appointments.
Based on their assessment, the physiotherapist will independently make three important
decisions: (1) whether the child requires dynamic ultrasound imaging of their shoulders
at the time of their first full clinic visit; (2) whether the child might benefit
from early Sup-ER (supination-external rotation) splinting for their shoulder[7]; and (3) whether the child requires evaluation by the full team prior to 3 months
of age—in the case of a completely flail upper extremity or presence of Horner's syndrome.[8]
Additionally, at this first meeting, stretching and ROM exercises are instituted to
maintain joint motion. Families are specifically instructed on how to complete the
exercises at home. For upper plexus injuries, exercises focus on shoulder, elbow,
and forearm movement. For total plexus injuries, the wrist and hand are also included.
The exercises are reviewed at subsequent visits with physiotherapy prior to the first
full clinic visit.
Perhaps, equally important is the opportunity for the family to meet a member of the
team in a nonthreatening environment and have their questions and concerns addressed.
An early point of contact is extremely helpful to provide education to the families
and explain the process of evaluation. Consequently, when the family comes for their
first full clinic visit, they have a basic understanding of BPBI and the typical protocols.
Being well informed helps to alleviate stress and anxiety surrounding their child's
care. If there are concerns regarding social support, financial stress, and/or family
dynamics, the clinic social worker can be engaged at this time as well.
First Multidisciplinary Clinic Appointment (3 Months of Age)
Most new infant referrals are seen for their first full multidisciplinary clinic appointment
at 3 months of age. Patients with severely affected extremities (flail limb, Horner's
syndrome) are a unique group and are seen as early as possible to discuss surgical
intervention.
History and Physical Examination
A standardized form is used to complete the history and ensure that all pertinent
features are recorded ([Fig. 2]). The physical examination is completed by an experienced physiotherapist and focuses
on determining AMS scores and assessing passive ROM. AMS scores are obtained for 14
domains of upper extremity movement: shoulder abduction/flexion/internal rotation/external
rotation, elbow flexion/extension, forearm supination/pronation, wrist flexion/extension,
finger flexion/extension, and thumb flexion/extension. Each movement is assigned a
score from 0 to 7 based on the AMS system[5]
[6] ([Table 1]). The surgeon evaluates the glenohumeral joint for any evidence of posterior subluxation.
Table 1
Active Movement Scale (AMS) scoring system[5]
|
Observation
|
AMS score
|
|
Gravity eliminated
|
|
No contraction
|
0
|
|
Contraction, no movement
|
1
|
|
Motion < ½ range
|
2
|
|
Motion > ½ range
|
3
|
|
Full motion
|
4
|
|
Against gravity
|
|
Motion < ½ range
|
5
|
|
Motion > ½ range
|
6
|
|
Full motion
|
7
|
Abbreviation: AMS, Active Movement Scale.
Fig. 2 Initial intake assessment form. The therapist obtains this information from the family
and referring physician at the initial visit. It is subsequently reviewed by the surgeon
at the 3-month multidisciplinary clinic visit. This information is also included in
our research database after obtaining guardian consent.
The physical examination also includes screening for coexisting torticollis, positional
plagiocephaly, Horner's syndrome, general muscle tone (increased or decreased), and
general development.
Indications for Primary Nerve Surgery at or before 3 Months of Age
Failed Test Score
The test score is calculated by converting the AMS scores at 3 months of age for elbow
flexion, elbow extension, wrist extension, finger extension, and thumb extension ([Table 2]). The converted scores are combined to obtain the final test score, out of 10.[3]
[5] Test scores less than 3.5 are an indication to recommend a primary nerve operation
at 3 months of age. If the test score is greater than 3.5, the decision for operative
intervention is deferred until the next clinic visit.
Table 2
Conversion score corresponding to AMS scores for the calculation of the test score
|
AMS score
|
Conversion score
|
|
0
|
0
|
|
1
|
0.3
|
|
2
|
0.3
|
|
3
|
0.6
|
|
4
|
0.6
|
|
5
|
0.6
|
|
6
|
1.3
|
|
7
|
2.0
|
Abbreviation: AMS, Active Movement Scale.
Note: The test score is calculated by adding the conversions scores for elbow flexion,
elbow extension, wrist extension, finger extension, and thumb extension, which generates
a score out of 10. The test score is only calculated when the infant is 3 months of
age; it is not validated for other time points.[3]
[5]
Flail Limb
Infants found to have a completely flail extremity and/or Horner's syndrome at the
initial intake assessment will be triaged to be seen earlier than 3 months of age,
ideally at 4 to 6 weeks of age. A discussion about early operative intervention is
held, and we initiate the surgical work-up. If there is no evidence of root avulsion
on imaging, we will wait until 8 weeks of age to perform the primary nerve operation
to ensure there is no evidence of rapid recovery of hand function indicating a neurapraxic
injury. If rapid return of hand function is seen, we will defer the decision to operate
until 3 months of age.
Complete Nerve Recovery by 3 Months of Age
Infants that have achieved full spontaneous recovery of their BPBI prior to 1 month
of age are considered to have a true neurapraxic injury and are expected to have no
long-term sequelae of their injury. These patients are discharged from our care following
the 3-month clinic appointment.
Infants that demonstrate complete recovery of upper extremity function between 1 and
3 months of age may, or may not, have subtle sequelae of their injury. These patients
may demonstrate differences in the active or passive ROM between the affected and
unaffected upper limbs, or differences in complex patterning of the upper limb. For
example, the affected limb may be tucked, or held at the side, when running. Consequently,
these patients are seen at 2 to 3 years of age to evaluate for any subtle differences
and provide appropriate education to the family where indicated.
Conditions Mimicking BPBI
Approximately 6% of patients seen in our clinic are ultimately found to have other
conditions that can be confused with a BPBI. These conditions include: pseudoparalysis
(secondary to humeral, clavicle, or rib fracture), cerebral palsy, spinal cord lesions,
and isolated radial nerve injury. These patients are then provided referrals to appropriate
care providers and discharged from our clinic.
Second Multidisciplinary Clinic Appointment (6 Months of Age)
The 6-month clinic appointment is specifically targeted at patients where there are
concerns regarding either (1) poor neurologic recovery or (2) shoulder dysfunction.
Prior to the 6-month visit, the patients are seen by our physiotherapist in a dedicated
visit to reevaluate nerve recovery and ROM, reinforce stretching exercises, and address
any new concerns. AMS scores and ROM values are recorded and compared with previous
scores to assess for nerve recovery.
Indications for Primary Nerve Surgery at 6 Months of Age
Patients that do not demonstrate significant improvement in AMS scores are considered
for primary nerve surgery. Specifically, if elbow flexion AMS scores remain less than
3, it is unlikely that the child will develop sufficient antigravity function by 9
months of age. The families of these patients are offered a primary nerve operation
at this visit. Patients with improvement in AMS scores return for follow-up at 9 months
of age.
Third Multidisciplinary Clinic Appointment (9 Months of Age)
The infant is reexamined and a final decision regarding a primary nerve operation
is made at 9 months of age. Specifically, we perform the “cookie test” ([Fig. 3]). This test requires the infant to be able to bring their hand to their mouth with
the shoulder held in adduction and less than 45 degrees of neck flexion.[3]
[5] A single demonstration of this ability is sufficient to consider the infant as having
completed the test successfully. If the patient clearly demonstrates the ability to
pass the test, then they are not offered an operation. Stretching and ROM exercises
are reviewed by the physiotherapist at this stage. Arrangements are made for follow-up
in clinic at 2 years of age, or earlier if there are ongoing concerns regarding shoulder
dysfunction or elbow contracture.
Fig. 3 Failed cookie test at 9 months of age. The infant is unable to sufficiently flex
their elbow to bring a cookie to their mouth with the shoulder adducted. (Reproduced
with permission from Swan and Clarke.[20])
Indications for Primary Nerve Surgery at 9 Months of Age
Persistently weak elbow flexion leading to an inability to pass the cookie test is
an indication for a primary nerve operation at 9 months of age. In rare circumstances,
elbow flexion has recovered and the cookie test is passed, but shoulder abduction,
flexion, and external rotation remain poor. We have recommended a primary nerve operation
in this setting as well.
Special Considerations: Infants with Poor Neurologic Recovery and Glenohumeral Dysplasia
In upper plexus palsies, every effort is made to manage the glenohumeral joint nonoperatively,
using the Sup-ER splint, botulinum toxin, and casting when needed, while we await
nerve recovery. In patients with both poor recovery of active external rotation and
persistent dysplasia/posterior subluxation of the glenohumeral joint, the resting
position of the shoulder (in internal rotation and adduction) can physically limit
the ability to fully flex the elbow. In these situations, it may be challenging to
accurately assess neurologic recovery of elbow flexion in infancy. We do not perform
the shoulder surgery and the nerve operation in the same setting, as we feel it is
important to evaluate the impact of one operation prior to proceeding with the other.
When nerve recovery is globally poor at 9 months of age (i.e., AMS less than or equal
to 5 for shoulder abduction/flexion and elbow flexion), a primary nerve operation
will be recommended as the first priority. Conservative management of the glenohumeral
dysplasia continues during this time; depending on nerve and functional recovery postoperatively,
surgical management of the shoulder joint may be recommended as a second stage.
In a highly select subset of infants with overall good nerve recovery (AMS greater
or equal to 6 for shoulder abduction and elbow flexion), who marginally fail the cookie
test and have poor external rotation and a subluxed shoulder, the glenohumeral joint
is surgically addressed first and upper limb movement reassessed 2 months later. If
the patient now passes the cookie test, no nerve operation is recommended. If the
patient is still unable to pass the cookie test, we offer a nerve transfer to augment
elbow flexion ([Fig. 1]).
Preoperative Planning
Selection of Operative Procedure
Neuroma Excision with Interpositional Nerve Grafting
Patients that meet criteria for a primary nerve operation are offered formal brachial
plexus exploration, neuroma excision, and reconstruction with sural nerve grafting
and possible extraplexal nerve transfers. Extraplexal nerve transfers are used in
situations where there are insufficient donor roots or insufficient graft material.
The most commonly utilized extraplexal nerve transfers include the spinal accessory
nerve (SAN) to suprascapular nerve (SSN) transfer via an anterior approach, and the
intercostal to musculocutaneous nerve transfer in total plexus injuries.
Role of Neurolysis
We have previously demonstrated that there is no role for neurolysis alone in the
management of these injuries.[9] The role of external neurolysis is limited to situations where a nerve is otherwise
normal but is surrounded by scar from a neighboring, more proximal nerve injury.
Role of Distal Nerve Transfers
In our practice, distal nerve transfers are utilized in select circumstances, including
late presentation after 12 months of age, lack of available donor roots (i.e., C5–C6
injury where both roots are avulsed), and in cases of otherwise good spontaneous recovery
when a specific movement fails to recover.[10] For example, patients without glenohumeral dysplasia but who fail to recover active
external rotation may benefit from the SAN to SSN transfer. Or, in patients who underwent
primary shoulder stabilization surgery and demonstrate persistently weak elbow flexion,
a single or double fascicular nerve transfer from redundant median and/or ulnar fascicles
is performed.
Nerve transfers as a complete, primary approach to BPBI are gaining popularity for
selected patients with upper trunk injuries, and thus far appear to have equivalent
postoperative outcomes.[11]
[12] However, further long-term data are required given that results of nerve grafting
have been shown to improve up to 4 years postoperatively.[13] As well, sensory outcomes following primary nerve transfers as a complete approach
are lacking. Consequently, our preferred approach at this time remains neuroma excision
and interpositional nerve grafting.
For patients with 4- or 5-root avulsion injuries, we consider transfer of the contralateral
C7 root to the lower trunk via a retropharyngeal approach. Our otolaryngology colleagues
assist us with the retropharyngeal dissection. There are limited data on the outcomes
following this transfer in infants with BPBI, but our personal experience and the
existing data[14] suggest that this approach is promising in these devastating injuries.[14]
Discussion and Consent Process
Discussion and Consent Process
The preoperative discussion begins with a detailed description of the nature of BPBI
and the rationale for treating the patient surgically. The risks of the operation
and the expected outcomes are explained. Care is taken to set expectations very clearly
with the family regarding the postoperative long-term prognosis. Based on our center-specific
data, 85% of children have improved function, 10% of children have similar function,
and 5% of children have reduced function. The families are informed that it will take
3 to 6 months before the child has returned to their preoperative baseline function.
We explain that we will not see the final functional outcome from the surgery for
up to 4 years postoperatively.
We specifically review the risks of pneumothorax, bleeding, phrenic nerve injury,
infection, and wound-healing issues, as well as the use of fibrin glue.[15]
Investigations
Imaging
All patients undergoing primary nerve surgery at Sick Kids undergo two preoperative
imaging studies: (1) diaphragmatic ultrasound and (2) computed tomography (CT) myelogram.
The ultrasound is completed to evaluate and document the function of the phrenic nerves.
A CT myelogram provides information regarding the presence or absence of pseudomeningoceles
and whether rootlets are seen crossing these pseudomeningoceles. A prior study at
our center demonstrated that a pseudomeningocele with absent rootlets on CT myelogram
had a specificity of 0.98 in correctly identifying a root avulsion.[16] However, its sensitivity was lower and thus CT myelogram alone was insufficient
to rule out root avulsion.[16] Nevertheless, the findings on CT myelogram provide good baseline information for
preoperative planning.
Electrodiagnostic Testing
We do not perform electrodiagnostic studies (electromyography and nerve conduction
studies) in the clinical management of our patients. We feel that these studies are
unreliable in this patient population and generally result in overly optimistic assessment
of neurologic recovery.[17]
[18] Consequently, we rely on clinical recovery to guide decisions on treatment.
Operative Protocol
A detailed description of our technical approach to microsurgical reconstruction of
the brachial plexus has previously been published[3]
[19]
[20] ([Table 3]). One can refer to these reports for details regarding sural nerve harvesting and
brachial plexus exposure/dissection. Briefly, we conduct sural nerve harvest first
in a prone position through three 2-cm transverse incisions, followed by a supraclavicular
approach to the plexus through a V-shaped incision in the supine position ([Fig. 4]).
Fig. 4 A V-shaped flap is created and reflected posterolaterally by an incision along the
posterior border of the sternocleidomastoid and the clavicle. Through this exposure,
the entire posterior triangle is visible. For longer lesions, the incision may be
extended along the deltopectoral groove, if necessary. The infant is positioned in
such a way that the surgeon may work above, beside, and below the field. The neck
is slightly extended, and the head faces away from the field. The hand and arm are
accessible for observation of stimulated movements. A clear plastic head drape is
used so that the patient's face and the nasotracheal tube are always visible to the
anesthetist and the other members of the surgical team. (Reproduced with permission
from Davidge et al.[19])
Table 3
A step-by-step approach to exploration of the brachial plexus[20]
|
Surgical steps
|
|
Tattoo preoperative markings to facilitate subsequent wound closure
|
|
Elevate skin flap in subplatysmal plane and reflect superolaterally
|
|
Divide clavicular head of the sternocleidomastoid and external jugular vein
|
|
Identify the cervical plexus and C4 nerve root; divide supraclavicular branches
|
|
Divide omohyoid muscle and reflect Brown's fat pad off the clavicle
|
|
Divide the transverse cervical and suprascapular artery and vein
|
|
Identify neuroma/plexus between anterior and middle scalene muscles
|
|
Identify phrenic nerve and perform neurolysis if required
|
|
Using the C4 marker, identify the C5 root and dissect proximally to the foramen to
exclude a preganglionic avulsion
|
|
Sequentially identify and dissect the C6 root and foramina, assess for a preganglionic
avulsion
|
|
Dissect antegradely along the lateral border of the brachial plexus to identify the
suprascapular nerve and the upper and middle trunks
|
|
Identify the remaining nerve roots and foramina, taking care to protect the subclavian
artery and parietal pleura, assess for a preganglionic avulsion
|
|
Identify the lower trunk of the brachial plexus and its branches distally
|
|
Review the operative findings:
|
|
1. Which roots appear intact?
|
|
2. The position and length of any neuromata that require excision
|
|
3. The position of distal plexus targets requiring nerve grafting
|
|
4. Length of sural nerve (±supraclavicular nerve) graft available
|
|
Perform intraoperative nerve stimulation to help differentiate between an intraforaminal
root avulsion and an intact nerve root if required
|
|
Prepare for neuroma excision and stump sampling for frozen section
|
|
Calculate amount of sural nerve graft required to reconstruct resultant defect and
consider options for intraplexal or extraplexal neurotization
|
|
Cut grafts to length for proposed plexus reconstruction in a tension-free manner;
prepare fibrin sealant
|
|
Ensure meticulous hemostasis within the wound bed; no further irrigation during gluing
of grafts
|
|
Glue grafts in situ using a fibrin sealant; ensure optimal orientation using an operating
microscope
|
|
Wound closure to include redraping of Brown's fat pad, repair of omohyoid muscle,
and reattachment of sternocleidomastoid muscle
|
|
No surgical drain required
|
|
Skin closure in layers using absorbable sutures; infiltrate local anesthesia
|
|
Simple wound dressing; application of Velpeau sling, or external rotation splint/cast
|
Source: Reproduced with permission from Swan and Clarke.[20]
Each nerve root and distal nerve target are carefully dissected and identified. Roots
are dissected proximally to the vertebral foramina to identify evidence of root avulsion
(visible rootlets and/or dorsal root ganglia identified in the operative field, an
“empty” foramen). The nerves are visually inspected and gently palpated to identify
the transition between firm neuroma tissue, and soft, pliable healthy neural tissue.
Distally, we dissect until healthy nerve is seen. The clavicle can be elevated to
facilitate better visualization. In rare circumstances for very distal lesions, we
have dissected on the caudal aspect of the clavicle, but do not perform a clavicular
osteotomy. The incision can also be extended along the deltopectoral groove to allow
for a complete infraclavicular exposure of the plexus as necessary. We rarely find
that this is necessary.
The nerve roots are stimulated and the response to stimulation recorded. Then, the
neuroma and scarred segments of the brachial plexus are excised, and the proximal
and distal nerve ends cut back to healthy-looking nerve. A fresh 15-blade scalpel
is utilized for each cut. The transected proximal and distal nerve ends are passed
off for pathology and carefully labeled.
Role of Neuropathology (Frozen Section)
It is critically important to cut back to healthy nerve ends to optimize nerve regeneration
and functional outcomes. When we reviewed how well visual inspection of the nerve
roots faired in comparison to frozen-section analysis, we found that frozen-section
analysis prompted reresection of at least one proximal nerve root in 25% of patients.[21] With increasing experience, this percentage likely decreases with time, yet frozen
section analysis remains a key component to our intraoperative protocol. Our surgical
team physically delivers the fresh specimens to the Pathology department. We participate
in the slide preparation process and ensure that all specimens are carefully labeled
for analysis. Once the neuropathologist has completed their initial evaluation of
the slides, the surgical team joins for a group review. Any concerns are addressed
directly at this time (i.e., equivocal/unusual pathological findings, note of particularly
challenging specimens to obtain, any relevant intraoperative findings). Once all slides
have been reviewed and the findings discussed, the surgical team returns to the operating
room. Recuts of any proximal or distal nerve ends are performed as necessary.
Active participation of the surgical team in this process recognizes the vital contribution
of the neuropathology team. We feel this empowers the pathology team to take ownership
of the case and helps provides direct clinical continuity. It also provides valuable
learning opportunities for the surgical team and trainees.
Final Evaluation of Donor Roots
The definitive decision regarding which nerve roots are viable donors is made by combining
preoperative and intraoperative information. Preoperatively, evidence of root avulsion
on CT myelography is combined with preoperative physical examination AMS scores to
determine presurgical probability of root avulsion. Intraoperatively, absence of a
response to stimulation, presence of visible dorsal root ganglia or rootlets in the
operative field, ganglion cells on frozen section, and an empty foramen are all further
evidence of a root avulsion injury. We abandoned the use of intraoperative electrophysiology
over 20 years ago, as we found it unreliable as a predictor of root avulsion.[22]
The quality of the nonavulsed proximal roots on frozen section is also important to
our decision-making as to what roots to graft from. For example, if a proximal nerve
root is cut back as proximally as possible but still shows evidence of scarring and
substantially fewer viable axons, we would not count on this root to provide useful
recovery. The reconstruction would be planned with the best quality roots and, if
residual nerve graft material was still available, we would graft from the poor-quality
root secondarily. Or, the poor-quality nerve root might not be used at all. Importantly,
an intraforaminally avulsed root can look completely normal on histopathology.
Reconstruction Design
Once the viable donor roots have been identified, the reconstructive plan can be created.
The gaps between each donor root and the distal targets are measured and recorded.
These measurements are typically transcribed graphically on a white board. The total
length of available nerve graft (sural and/or cervical plexus) is recorded. A proposed
reconstruction is designed and drawn schematically, taking into consideration the
gap distances and the length of nerve graft available.
Anatomic reconstruction is preferred if appropriate nerve root donors are available
([Fig. 5]). However, when root avulsions are present, nonanatomic reconstructions must be
employed. In all cases where the lower trunk is involved, hand function is prioritized.
The most important consideration is to robustly reconstruct the lower trunk to provide
optimal hand function. Multiple cable grafts are directed from viable nerve roots
to the lower trunk. The “best” root will be used for hand reconstruction, even if
this results in a nonanatomic reconstruction.
Fig. 5 Intraoperative case example of neuroma resection and interpositional nerve grafting
in an infant with BPBI. The upper trunk (C5, C6) demonstrated a neuroma-in-continuity.
The middle trunk (C7) was ruptured and the proximal and distal ends scarred to the
upper trunk neuroma. Avulsion of C8 was confirmed unequivocally by the presence of
a dorsal root ganglion in the surgical field. T1 was found to have a normal fascicular
pattern with minimal involvement in the neuroma; external neurolysis was completed.
The C5, C6, and C7 roots were all cut back to healthy nerve. Anatomic grafting was
performed from C5 and C6 to the suprascapular nerve, anterior and posterior divisions
of the upper trunk. Intraplexal neurotization to distal C8 was performed from C7.
The lower quality graft material (cervical plexus graft) was utilized to graft from
C7 to middle trunk. The phrenic nerve is shown traversing longitudinally over the
plexus. (Reproduced with permission from Davidge et al.[19])
When anatomic reconstruction of upper trunk is possible, equal priority is given to
the anterior and posterior divisions. Ideally, there should be contributions from
both C5 and C6 to each division (grafts running from both roots to both divisions).
If only one of C5 or C6 is available for upper trunk reconstruction, then the single
available donor root is used to graft to both posterior and anterior divisions of
the upper trunk.[23] Typically, the posterior division of the upper trunk is larger and can accommodate
up to three grafts, whereas the anterior division is smaller and can accommodate up
to two grafts on average. Reconstruction of the middle trunk is given the lowest priority
overall.
As noted earlier, the SAN to SSN transfer may be used in cases where there is either
insufficient graft material or donor nerve roots. This transfer is robust and synergistic
in function. We and others have demonstrated that outcomes of grafting from C5 versus
nerve transfer from SAN are equivalent.[24] Direct transfer of three intercostal nerves to the musculocutaneous transfer is
considered in cases of total plexus injury with limited donor roots.
Reconstruction Method
All nerve coaptations are performed with fibrin glue under the operating microscope.
Postoperative Care
Immobilization and Dressings
Choice of postoperative immobilization is based on the presence or absence of glenohumeral
dysplasia. If there are concerns regarding glenohumeral dysplasia, we will immobilize
the patient in an external rotation cast or splint. Otherwise, a Velpeau-style sling
is applied[25] ([Fig. 6]). This sling is applied using stockinette and safety pins, and is inexpensive, comfortable,
and easy to use. Either way, dressings are maintained for 3 weeks. The neck is not
immobilized in any of our patients.
Fig. 6 Velpeau sling. The Velpeau sling is inexpensive and securely maintains the reconstructed
extremity in full internal rotation with the elbow fixed at 90 degrees of flexion. (Reproduced
with permission from Borschel and Clarke.[3])
The sural nerve harvest sites are dressed with Friar's balsam, Steri-Strip, gauze,
Sof-Rol, and Kling wrap. The Sof-Rol and Kling wraps extend from the toes to above
the knees. These outer dressing are allowed to fall off in the first 1 to 2 days postoperatively
as the patient moves around.
Hospital Course
Patients are admitted to hospital postoperatively to a constant observation setting
on our Plastic Surgery inpatient unit. Patients are monitored for complications, specifically
any respiratory insufficiency, and provided analgesia in the form of acetaminophen,
ibuprofen, and oral morphine.
Discharge Home and Follow-up
Patients are typically discharged on the second postoperative day. Patients are seen
for the first follow-up in clinic at 3 weeks postoperatively. The immobilization device
is removed at this visit and the wounds are inspected. The physiotherapy team begins
stretching and mobility exercises at 5 weeks postoperatively. The parents are provided
with ongoing education regarding expected timelines for recovery and improvement.
Management of Glenohumeral Dysplasia in BPBI
Management of Glenohumeral Dysplasia in BPBI
Glenohumeral dysplasia is common in infants and children with BPBI, particularly those
with upper plexus injuries. Strong internal rotator muscles often overpower the weaker
external rotators, leading to abnormal positioning of the shoulder in internal rotation.[26]
[27] This can result in remodeling of the glenohumeral joint, eventually leading to glenohumeral
dysplasia and posterior humeral head subluxation. The impact of shoulder dysfunction
is increasingly being recognized, and our clinic has adjusted our practice to address
this issue. There is currently no consensus on the optimal management of the shoulder
in BPBI.
Management of the Shoulder in Infancy
Initial Intake Assessment by Physiotherapy
It is imperative to identify patients at risk of shoulder dysfunction as early as
possible. Early identification enables the team to institute treatment quickly, potentially
preventing the longer-term sequelae associated with abnormal shoulder positioning.
The physiotherapist initiates passive ROM exercises for the shoulder as of the initial
visit.
Clinical Examination
During each clinical visit, the glenohumeral joint is evaluated for any evidence of
posterior subluxation of the humeral head. The examiner places one hand on the infant's
shoulder with their thumb on the humeral head. The other hand is placed on the distal
humerus at the level of the epicondyles. The humerus is moved through internal and
external rotation, while the humeral head is palpated for evidence of posterior subluxation.
Both shoulders are examined to enable comparison to the contralateral side.
Dynamic Ultrasound Imaging
Indications for scheduling a dynamic ultrasound of bilateral shoulders at 3 months
of age include any tightness into passive external rotation and/or external rotation
AMS score less than or equal to 2 for at the initial visit with the physiotherapist.
During the test, each shoulder is examined in internal and external rotation to assess
the position of the humeral head in relation to the glenoid fossa. The affected limb
is compared with the contralateral side for reference. An absolute α angle of >30 degrees
is considered abnormal.[28]
[29] However, the α angle itself does not dictate our level of concern or treatment.
Rather, it is the ultrasound findings in correlation to the clinical examination that
guides management.
Sup-ER Splinting and Botulinum Toxin
Conservative management of the shoulder joint aims to improve passive ROM, maintain
congruity of the glenohumeral joint, and improve muscle balance while the nerves are
recovering.
The Sup-ER splint was pioneered by the team at the British Columbia Children's Hospital
to treat infants with glenohumeral instability. The splint functions to keep the infant's
arm in a supinated and externally rotated position to decrease the risk of developing
glenohumeral dysplasia[7] ([Fig. 7]).
Fig. 7 The Sup-ER splint has two components: a thermoplastic splint and a diaper-like elastic
waistband. The arm splint holds the elbow in extension and supination. Two straps
connect the arm splint to the posterior waistband of the diaper to position the shoulder
in external rotation and hold the humeral head within the joint. The position of the
glenohumeral joint in the splint can be confirmed with ultrasound. (Reproduced with
permission from Zuo et al.[32])
If there is clinical and/or radiologic evidence of glenohumeral instability, we recommend
treatment with Sup-ER splinting. This decision may be made prior to the 3-month assessment
if deemed prudent by the physiotherapist at the early evaluations. The Sup-ER splint
is fabricated on the same day by our occupational therapy team and the parents are
instructed to apply the splint at night and during naps. If a Sup-ER splint is initiated,
the patient will be seen in our occupational therapy department in 2 to 3 weeks to
ensure a proper fit and compliance with the splinting protocol.
For patients with ongoing evidence of glenohumeral instability, the Sup-ER splint
is continued for as long as the infant can tolerate it. We find that it is often challenging
to continue Sup-ER splinting in infants older than 6 months
If the Sup-ER splint alone is insufficient to hold the humeral head in joint, our
next step is to utilize botulinum toxin A injections to the strong internal rotators,
followed by casting in external rotation. Botulinum toxin is injected into the pectoralis
major, latissimus dorsi, and subscapularis muscles in the main operating room. Although
botulinum toxin can be effective in the short term, its benefit is not sustained over
time and a significant proportion of patients with glenohumeral dysplasia will still
require secondary shoulder surgery.[30]
[31]
Primary Shoulder Surgery within the First Year of Life
As outlined previously, a small subset of our patients is recommended for primary
shoulder surgery in infancy ([Fig. 1]). We counsel the families that shoulder surgery changes the location of the internal–external
rotation arc but does not increase it. Our goal is to have the child be able to internally
rotate to touch their belly and externally rotate to at least neutral. We also counsel
families that there is a 5% chance of reoperation due to under- or overcorrection
of the internally rotated posture.
Primary shoulder surgery at our center typically consists of teres major and latissimus
dorsi tendon transfers, in addition to a subscapularis slide. The tendon transfers
reorient teres major and latissimus dorsi into shoulder external rotators, correcting
the underlying muscular imbalance. These two tendons are reinserted separately into
the greater tuberosity of the humerus, rather than as a conjoined tendon.[32] The subscapularis slide allows partial release of the tight internal rotator, reducing
the internal rotation contracture. Following shoulder surgery, the infant is immobilized
for 4 weeks in external rotation, following which several weeks of physiotherapy are
required to stretch the shoulder back into internal rotation.
Late Management of the Shoulder in BPBI
We continue to monitor the shoulder joint beyond the first year of life. Our team
screens for joint contracture and abnormal positioning of the joint. Active and passive
ROM is meticulously documented to assess trends and identify concerns as early as
possible. Physiotherapy is recommended to improve and maintain passive ROM around
the shoulder. Secondary shoulder surgery is indicated in children who lack active
external rotation and in those with progressive glenohumeral dysplasia to promote
joint remodeling. Preoperative magnetic resonance imaging (MRI) of bilateral shoulder
joints is used for operative planning and staging of the dysplasia using the Waters
classification.[33] In children younger than 4 years, tendon transfers alone may be sufficient to allow
for glenohumeral remodeling. However, older children and adolescents require open
joint reduction with glenoid anteversion osteotomy in addition to teres major and
latissimus dorsi tendon transfers. Details of the surgical technique at our center
have been previously published.[34] Postoperatively, the patients are maintained in an external rotation splint for
4 weeks. At that time, the splint is removed and the physiotherapy team begins a postoperative
ROM protocol.
Outcome Assessment
Rigorous evaluation of clinical outcomes following BPBI surgery is vital for continued
optimization of care. Our clinic maintains a robust patient database, which includes
all patients that are seen by the team (including both operative and nonoperative
cases). This facilitates longitudinal assessment of patient outcomes.
Our clinic utilizes multiple tools to track outcomes; the choice of tool depends on
the age of the patient.
Birth to 4 Years of Age
Infants and young children are evaluated using the AMS scoring system and documentation
of passive ROM values. These children are too young to employ other tools that require
patient compliance and the ability to follow specific direction.
Patients Older Than 4 Years of Age
Older children are more reliably able to engage with examiners and complete more complex
evaluations. These children undergo several detailed assessments by our physiotherapy
and occupational therapy teams:
-
Active ROM (all domains of upper extremity movement).
-
Mallet score.[35]
-
BPOM.[36]
-
Sensory and pain evaluation by occupational therapy.
Long-term Follow-up
All patients with BPBI are followed in the clinic until they are 18 years old (regardless
of whether they required a primary nerve operation). As children grow, it is common
to encounter new functional concerns, and these are addressed at subsequent clinic
appointments. Patients are typically followed in the full clinic on a yearly or biyearly
basis depending on their concerns and progress.
Conservative Management
Patients with active rehabilitation concerns are followed more closely by the specific
teams involved (physiotherapy or occupational therapy).
We know that affected muscles in BPBI do not grow longitudinally to the same extent
as nonaffected muscles.[37] Therefore, a common concern during childhood and adolescence is loss of passive
and active ROM after periods of growth, requiring bursts of therapy to regain motion.
In particular, elbow flexion contractures are common and for the most part are managed
nonoperatively, with a combination of stretching, splinting, and/or serial casting.[38] The management of elbow flexion contractures is an area of active research at our
center.[39]
For functional concerns, our occupational therapy team provides support, adaptive
devices, and education to enable patients to meet specific goals (i.e., sports, writing,
grooming/hygiene, dressing, etc.). Management of pain, which is still not well understood
in BPBI, consists of multimodal therapy including massage, heat, activity modification,
stretching, and specific exercises. When pain is severe, we refer to our multidisciplinary
pain clinic.
Other Secondary Surgeries
Decisions around secondary procedures for the elbow, forearm, wrist, and hand are
made on an individualized basis and are carefully considered to ensure that the operation
will enhance but not downgrade function. This requires comprehensive functional assessments
by our therapists and thorough discussion with patients and their families.
Peer Mentorship Program and Brachial Plexus Family Day
Patients with BPBI often benefit from support from peers, specifically those who may
have similar functional concerns or those who previously underwent surgery. Our clinic
offers a Peer Mentorship Program, which connects older patients (volunteers) with
younger patients to provide support and guidance. Additionally, patients and families
are invited to participate in the annual Brachial Plexus Family Day, which provides
an opportunity to meet other patients/families/caregivers and provide support for
our patients. These events have been very well received by patients and families alike
and we consider them vital to the overall Brachial Plexus Clinic program.
Conclusion
Management of patients with BPBI is complex, challenging, and requires longitudinal
care by a compassionate and dedicated multidisciplinary team. This article has described
the current approach taken by the team at Sick Kids Hospital. Our research database
has been central to providing evidence-based care of these children and will continue
to allow us to evaluate and modify our management algorithm to optimize patient care.
As we look to the future, we are excited to focus more on patient-centered outcomes
and to engage in international collaborative research that has even greater potential
to drive improvements in care for patients of all ages with BPBI.
