Introduction
This chapter will cover a few diseases involving a lot of uncertainties, especially with regard to clinical diagnosis and treatment strategies. Treatment of these diseases is often controversial. Consequently, these diseases present major fields for research and great potential for enhanced understanding. This is why they are presented in the last chapter of this book.
Brachial plexus birth palsy (Gürsel Leblebicioğlu)
Brachial plexus birth palsy is characterized by loss of sensory and motor functions of the upper extremities caused by trauma to the brachial plexus during delivery. In some cases, birth palsy may be severe and result in a completely dysfunctional upper extremity. It can be unilateral or bilateral and is distressing and devastating for the family. Different nomenclatures, such as obstetric brachial plexus palsy, obstetric palsy, or obstetric brachial plexus injury (OBPI) , are used to express the same problem. It is an uncommon and unpredictable condition in obstetrics and may have serious medicolegal consequences for healthcare providers. In the last 40 years, there has been an increase in the awareness of birth palsy all over the world. There have been and continue to be intense developments in microsurgical reconstruction of the brachial plexus, functional restoration of secondary problems, and physical therapy methods. It is certainly important to avoid this serious problem with preventive approaches ( Box 36.1 ).
Etiology and incidence
When there are other signs of traumatic delivery, the palsy may have been caused by crushing and stretching. It can also occur in completely normal or cesarean deliveries. In these cases, it is possible to consider intrauterine problems or pathologies in the birth canal that may have prevented normal delivery. Among the approximately 2000 patients with birth palsy who I have personally examined, a mother’s weight gain of 15 kg or more during pregnancy and a birth weight of the baby more than 4000 grams are the most common features. I have seen birth palsy in premature newborns who weigh 2000 grams. While macrosomia is the most important cofactor, other mechanical causes probably play a role.
In a study examining a database of over 24 million births, the incidence of birth palsy was found to be 0.9 per 1000 live births. Shoulder dystocia was found to be the number one risk factor. Between 1997 and 2012, there was a significant and stable decrease in the incidence of birth palsy. However, in more than half of the cases, a risk factor could not be found. There have also been hypotonic babies in my personal patient series, and it was found that the cesarean delivery rate increased significantly in the same period. Although the frequency of birth palsy is lower among cesarean births, it occurs nonetheless. High birthweight and shoulder dystocia were the strongest risk factors for obstetrical brachial plexus palsy in a Swedish population-based study. Cervical rib and abnormal scalene muscles may also increase the risk.
Of approximately 2000 patients I have personally seen and examined, 10 had two or three siblings who also had birth palsy. This may be an indication that the same risk factor can continue in familial settings. In four of those patients, birth palsy was bilateral. All of these bilateral cases involved breech presentation. In shoulder dystocia, lateral deviation of the neck and axial traction during delivery may cause damage to the upper and middle trunks. In breech presentations, bilateral involvement may occur because axial traction is applied in the last stage.
Pathological anatomy
In children with brachial plexus birth palsy, the upper trunk (C5 and C6, or Erb palsy) is most often involved. Involvement in the entire plexus (C5 to T1) is seen less often. Mechanically, traction of the plexus causes injuries such as (1) stretching of the nerves without disruption, (2) rupture of the nerves (postganglionic tear, which is possible to repair surgically), or (3) avulsions from the spinal cord (preganglionic tear, which cannot be repaired surgically). The stretching without disruption of nerves or with partial axonal disruption is fortunately most common and recovers to varying degrees over months or years without surgery. The latter two pathologies cannot recover without surgery.
In the first 3 to 4 months after birth, the true pathologies are difficult to determine. Clinical observation of the recovery over months or histological examination during surgery can indicate the true pathologies.
Clinical presentation
Hand surgeons are often consulted after a traumatic delivery because of deficiencies in movement and sensation in the upper extremity. A pregnancy that started with great hope and joy ended in a sad situation for the patient’s family and the delivery team. In such a situation, the calming attitude of the hand surgeon is important. It should always be kept in mind that it is a sensitive period for the family, and attention should be paid to attitudes and behaviors. From the moment of the first examination, correct guidance of the parents is an invaluable asset for the baby.
Check for respiratory difficulty, clavicle and humerus fractures.
Careful examination of a newborn provides important information to determine prognosis and guide treatment. First, it is necessary to check whether there is respiratory difficulty. Since the phrenic nerve may be affected in traumatic deliveries, it is necessary to examine the presence of asymmetric thoracic movements during breathing. In terms of possible brachial plexus reconstruction, phrenic nerve palsy or hemopneumothorax is a vital problem that requires attention. Examination should also be performed in terms of clavicle and humerus fractures. Chest radiographs are usually taken after traumatic births. The clavicle is mostly broken in the mid-diaphysis. Proximal metaphyseal fractures and supracondylar fractures can be seen in the humerus. These fractures themselves prevent upper extremity movements and can mimic paralysis.
If the baby is asleep, this is an important opportunity to lightly squeeze the thumb, middle finger, and little fingertips to see if the baby reacts. The awake newborn is examined in the supine position to see if the baby follows colorful lights and sound-making toys. Allowing free movement, upper extremity movements are observed.
Brachial plexus birth injuries are not isolated problems. The soft tissues in the neck ( Fig. 36.1 ), cervical spine ( Fig. 36.2 ), scalene muscles, phrenic nerve, lungs, and pleura may be injured together with the nerves. Clavicle and humerus fractures can also be seen ( Figs. 36.3 and 36.4 ).
Examination of shoulder movement for C5 and C6.
Abduction of the shoulder, albeit slight, in the supine position is a sign of function in the C5 root and upper trunk. Likewise, active elbow flexion may be a sign that the C6 root and upper trunk are intact. It is also a practical method to observe shoulder and elbow movements while the baby is held by the pelvis and tilted to the right or left side. The shoulder is flexed 90 degrees, and the humerus is made vertical to see if there is active elbow extension ( Fig. 36.5 ).
The general movements of the affected extremity are examined. The presence of abduction in the shoulder is checked. While the infant is turned to the side, check whether the baby is in control of the shoulder. A slight shoulder abduction movement when tilted to the side means the C5 root is preserved. While the shoulder joint is abducted and the humerus is fixed to the bed and kept motionless, elbow flexion indicates the C6 root is preserved ( Fig. 36.6 ).
Examination of elbow movement for C7, wrist and fingers for C8 and T1.
A strong elbow extension indicates the C7 root and middle trunk are functional. Wrist extension and finger movements also provide information about the condition of C8, T1 roots, and the lower trunk. The presence of ptosis in the awake newborn and the absence of mydriasis in the dark may be signs of avulsion of the C8 and T1 roots. This is the Horner sign and is an indicator of poor prognosis. Check for finger flexion and thumb opposition. Infantile reflexes are very helpful during this examination.
Examination of passive motion of the joints.
It is important to look at the passive range of motion in the shoulder. Similarly, passive flexion and extension at the elbow, pronation and supination of the forearm, and passive flexion and extension of the wrist are sufficient. The baby is turned prone. The head is placed on the bed in a comfortable position, and the thorax is lifted off the bed by supporting both elbows.
Other examinations.
In the meantime, if the scapula remains fixed on the thoracic wall, the serratus anterior function is preserved ( Fig. 36.7 ). If the serratus anterior is paralytic, it is likely that there is C5, C6, and C7 root damage. If this resulted from a breech delivery, there is a possibility that these roots are avulsed. If scapular winging and Horner sign coexist in a newborn, the brachial plexus is probably completely avulsed ( Fig. 36.8 ).
During the first examination of the newborn, also check for signs of limb and spine malformations and dysplasia of the hips. Such problems may be overlooked in the panic brought on by birth palsy.
During the first baths given to newborn babies, a hot flushing reaction is observed in the innervated areas. This reaction may not be seen in the denervated area. I advise parents to prepare their cameras or smartphones before giving their babies a warm bath. I want them to take pictures of the color changes that may occur during the bath. I call this test the “hot bath” test. It is especially prominent in the C5, C6, C7 dermatomes ( Fig. 36.9 ). While it disappears within weeks in babies who are recovering, this period is longer in babies who are severely affected.
Repeating these examinations at 3 months of age.
The examination should be repeated when the baby is 3 months old, which is the time when treatment decisions can be made. It is important to note the presence or absence of shoulder abduction and external rotation, elbow flexion, and the Horner sign. If there is no nerve healing, active movements will be absent. If there is partial nerve recovery, unbalanced recovery in the joints may be the harbinger of future problems. For example, if there is no active external rotation of the shoulder and passive external rotation cannot be performed, it is likely that glenoid dysplasia is developing. If active external rotation occurs in the glenohumeral joint in the early period, the probability of glenohumeral dysplasia decreases. If active and passive external rotation are absent, check to see if the humeral head is posteriorly prominent. Ultrasonographic examination can be used for this purpose. If the humeral head is posteriorly prominent, glenohumeral dysplasia will likely develop.
The early element of limited passive external rotation may be stiffness and shortness of the subscapularis muscle. This also applies to the elbow flexors. The tendency toward flexion contracture in the elbow is a sign that the biceps muscle remains relatively short. In this case, the radiocapitellar joint should also be examined. Varus deformity with a tendency toward flexion contracture at the elbow is an indication that radiocapitellar dysplasia is developing.
Examination of older children (>3 months).
In older children, in addition to assessing the progression of neural recovery, providers should also look for the appearance of secondary changes. Especially in children with C5, C6, and C7 dysfunction, the return in muscle function is accompanied by imbalances observed around the joints. Internal rotation contracture in the shoulder is associated with weakness of the infraspinatus and teres minor muscles, despite strong subscapularis and pectoralis major muscles. The development of glenoid dysplasia caused by posterior displacement of the humeral head and the development of radiocapitellar dysplasia caused by anterior displacement of the radial head show structural and temporal similarities.
If the flexor muscles of the elbow are strong but the triceps muscle remains weak, flexion and supination contracture may develop. As the elbow is forced into extension, the strong, short, and rigid biceps muscle can pull the radial head away from the capitellum and cause radiocapitellar dysplasia and dislocation.
If the wrist extensors are weak, flexion contracture occurs when the wrist and finger flexors are strong. Such problems should be carefully evaluated, especially in children older than 5 months of age, and appropriate orthotic use and physical therapy should be initiated.
Examination of secondary problems in adolescence.
Solving secondary problems in adolescence is important for psychosocial development. , During this period, the adolescent spends more time with peers, and it is of primary importance and priority that the individual’s physical appearance is not disturbing. Unhindered toilet care in school life is also a priority. The surgeon should try to provide a grasping hand and shoulder and elbow function that can take the hand to the perineum.
Internal rotation contracture in the shoulder makes hair and head care difficult. A forearm supination contracture makes it difficult to dress and grasp objects. It makes using a computer mouse and keyboard difficult, if not impossible. Patients who have reached adolescence are asked to rank such problems in order of importance, and solutions are sought in accordance with this order. A general impression of the sensory, motor, and balance functions of the upper extremity can be obtained using the “balancing bird” test. In this test, the patient attempts to balance a balancing bird on each hand, preferably on the palmar surface of the middle fingertips. The position of the trunk and the extremity while walking allows the problems to be observed ( Fig. 36.10 ). Stabilometric evaluation is also used to examine postural balance.
Two muscles that are the initiators of secondary problems are the subscapularis ( Figs. 36.11 and 36.12 ) and biceps. The changes in the internal structures of these muscles during the neonatal period when they are denervated cause shortness later (when they are reinnervated) and limit movement in the adjacent joints. In addition to the weakness of the serratus anterior, the shortness of the pectoralis minor and biceps muscles may play a role in the development of scapular dyskinesia. It is wrong to explain scapular winging as serratus anterior weakness in children whose shoulder abduction and elbow flexion have recovered. Since the lower part of the scapula is mostly covered by soft tissue, the scapular orientation cannot be determined easily or reliably. I perform a “supination test” to show the effect of the biceps muscle on the scapula. In this test, the observer stands behind the patient. Both shoulders are flexed to 90 degrees. In pronation and supination, the position of the scapula on the thorax is checked ( Fig. 36.13 ). Another reason for abnormal mobility of the scapula may be the limitation of glenohumeral joint movement. Global movement in the shoulder is possible with a combination of the glenohumeral and scapulothoracic joint movements. Decreased mobility of the glenohumeral joint can be compensated for by movement in the scapulothoracic joint.
Fig. 36.14 shows the increase of passive external rotation with subscapularis release. The subscapularis muscle alone is one of the most influential anatomical structures in the development of an internal rotation contracture. , Although there can be an increase of more than 60 degrees in external rotation with subscapularis release, there may be a loss of around 20 degrees in internal rotation. External rotation gain can improve glenoid remodeling. Although a general increase in shoulder movements is observed clinically, concentric reduction does not occur in the humeral head. The age of the patient at the time of surgery is probably a determining factor. The loss of active internal rotation caused by this procedure can lead to marked limitations in activities of daily living. Only proximal release of the subscapularis from the subscapular fossa may be sufficient.
I use a “stick test” to examine the effect of elbow extension weakness on the shoulder joint. In this test, I raise the hand on the affected side as high as possible, and the maximum abduction of the shoulder joint is measured. Then, a stick or a long ruler is applied with an elastic bandage to keep the elbow in extension, and any increase in the shoulder abduction angle is noted ( Fig. 36.14 ).
Attention to other proximal pathological changes
For traction damage to occur to a nerve during delivery, the nerve must be fixed at a minimum of two points that move away from each other. The proximal fixation points in the brachial plexus are at the levels of the intervertebral foramen, especially those of the C5 and C6 roots. The distal fixation points are the places where entrapment neuropathies are encountered, such as the suprascapular notch ( Fig. 36.15 ), quadrangular space ( Fig. 36.16 ), supinator arcade ( Fig. 36.17 ), coracobrachialis muscle ( Fig. 36.18 ), pronator arcade, and cubital tunnel ( Fig. 36.19 ). At these points where the nerves pass through narrow areas, the tension created by the proximal traction force may cause crushing and compression at a second point. In other words, the distal healing pathways of the nerves damaged in birth palsy also require attention. If there is a delay or insufficiency in functional gain in the reconstructed nerves, these distal points should also be clinically evaluated. After sufficient time has passed following brachial plexus reconstruction, if pain is provoked by deep palpation at these distal points, a situation called “secondary impingement” may be occurring. In such a case, decompression of these secondary entrapment points may result in better recovery.
Clinical diagnosis
Box 36.1 summarizes the key points in clinical evaluation and treatment planning. Box 36.2 summarizes the key points of clinical diagnosis. The decision for surgery is made during the examination. Considering that the optimal time for nerve reconstruction is 3 to 6 months of age, the examination performed during this period is very important.
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Detailed examination of the newborn is important in terms of differential diagnosis and determination of prognosis.
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A knowledgeable and experienced physiotherapy team can provide better functional results.
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If there are permanent denervation findings by the end of the third month, microsurgical reconstruction should be considered.
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The sooner the neural reconstruction can be done, the better the results.
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Secondary problems are most likely caused by the stiffness and shortness of the muscles that remained denervated in infancy.
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Inadequate shoulder movements and glenoid dysplasia are the most common secondary problems.
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Many secondary problems can be prevented with effective physiotherapy.
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Soft tissue releases and muscle transfers may be beneficial in early childhood.
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In the late period, osteotomies may also be beneficial.
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An effective physiotherapy and timely surgical interventions can provide the acquisition of some useful functions, even in severe birth palsy.
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Clinical examination in the newborn period provides invaluable information about the anatomical location and degree of damage.
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After the newborn period, recovery is monitored during examinations performed at regular intervals.
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If the improvement does not occur or if an improvement is observed below the expected, detailed electromyography (EMG) and magnetic resonance imaging (MRI) examinations can be made.
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EMG examination should be performed not only for analysis of the damage, but also for nerves such as the spinal accessory nerve, intercostal nerves, dorsal scapular nerve, and triceps motor branches that can be used as donor sites during a surgical intervention.
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Evaluation of the shoulder region as well as nerve avulsions and ruptures in MRI is important for the evaluation of glenoid development.
Ancillary diagnostic methods are used to determine the surgical strategy rather than diagnosis. The most commonly used auxiliary diagnostic tools are magnetic resonance imaging (MRI) and electromyography (EMG). After the development of MRI technology and the use of neurography sequences, the chance to obtain detailed images in infants has emerged.
More valuable data can be obtained if the cervical spine, the damaged brachial plexus, and both shoulders are included in the examination area. In the MRI examination, attention is paid to the presence of a space-occupying lesion in the spinal canal. Presence of pseudomeningocele may be an indirect indicator of root avulsion. In birth palsy, from most common to least common, we see avulsions of C8, C7, T1, C6, and C5 roots. C5 and C6 roots more frequently rupture at the extraforaminal level, while proximal root avulsions are most common at C8 and T1.
Although ultrasonography is useful for the evaluation of C5 and C6 roots, it is insufficient for the evaluation of C8 and T1 roots and the lower trunk. MRI is currently considered the most sensitive method for the evaluation of glenoid dysplasia. Ultrasonography is also an effective tool in this regard, but it is preferred for use as a screening tool or for observing remodeling of glenoid retroversion after surgery.
It is valuable that MRI findings often overlap with clinical examination findings. If there is incompatibility between these, the possibility of anatomical variations of the brachial plexus should be considered. Visualization of both shoulders is important for the evaluation of glenoid dysplasia and humeral head sphericity. In this way, all problems that exist before the possible surgical intervention will be revealed. For many reasons, including legal reasons, it is important to perform all the necessary examinations before performing any surgical intervention. If advanced glenoid dysplasia is observed, the family should be informed that further surgical interventions may be required.
In cases in which the glenohumeral external rotation angle is less than 45 degrees, ultrasound can provide information about glenoid dysplasia. It is a sign of posterior dislocation when the proximal epiphyseal bone nucleus of the humerus is seen behind the dorsal scapular line.
In addition, EMG examination information can also be obtained for planning distal nerve transfers. The presence of normal EMG findings in the rhomboid muscles may mean the integrity of the C5 root is preserved. EMG evaluation of the trapezius muscle is valuable for the possibility of spinal accessory nerve transfer. EMG is a safe method to differentiate preganglionic and postganglionic injury.
Some infants may have a damaged chest walls or had a thoracic tube inserted in the neonatal unit. In such babies, EMG is valuable for evaluation of the intercostal nerves. EMG can also be used to investigate the cocontraction properties of muscles with synkinetic activity. After microneural reconstruction of the brachial plexus, EMG provides limited contributions to the monitoring of healing and this examination may reduce the infant’s physiotherapy compliance.
Differential diagnosis
Diagnosis in birth palsy is not difficult in most cases. But at times, especially for newborns, it may not be easy. One important differential diagnosis is cerebral palsy, and coexistence of birth palsy and cerebral palsy is often seen. In both cases, the obstetric history may show similar features. While the immobile extremity shows signs of movement over time in birth palsy, spasticity begins to be observed after 4 to 5 months in cerebral palsy. Internal rotation contracture tends to appear in the shoulder in birth palsy, and forearm pronation contracture and thumb-in-palm may appear in cerebral palsy. These two differences may be useful in forming the differential diagnosis.
Arthrogryposis multiplex congenita (AGMC) should be considered. Mild forms involving a limited area can be confused with birth palsy. While passive joint range of motion is preserved in newborns with birth palsy, passive joint movements are markedly restricted in AGMC.
Tuberculosis vaccine is usually applied to the skin over the deltoid muscle. After vaccination, an extreme reaction may occur in the supraclavicular lymph nodes in some babies. If a reconstruction of the brachial plexus is to be performed, this overreaction in the lymph nodes is undesirable; it may be preferable not to administer this vaccine (perhaps all childhood vaccines) in the paralyzed extremity.
Birth palsy can be seen in diseases associated with macrosomia. Maternal diabetes and hypogenitalism are among these disorders. In the differential diagnosis, it is necessary to consider problems related to the spinal cord. A spinal arachnoid cyst and other space-occupying lesions involving the spinal cord can cause symptoms very similar to those of birth palsy ( Fig. 36.20 ). Very early onset anterior motor horn diseases may be considered in the differential diagnosis. Despite the severe motor loss, normal sensation is a finding helpful in the diagnosis. In this case, an EMG examination can provide useful information.
Another disorder to consider in the differential diagnosis is infiltrative lesions of the brachial plexus. There are reports that infantile fibrosarcoma and desmoid tumors infiltrate the brachial plexus in the newborn stage and early infancy. I had a case involving infantile myofibroma with birth palsy ( Fig. 36.21 ).
Determination of pathological changes during surgery
Depending on the severity of the injury, at 3 months of age, recovery is observed in infants without nerve disruption or avulsion, but recovery does not occur in infants with nerve ruptures or root avulsion. Among the infants with rupture or avulsion, ruptures of the nerve occur more often in C5, C6, and C7 roots ( Fig. 36.22 ), while avulsions are more often seen in C7, C8, and T1 roots ( Fig. 36.23 ).
Only histological sections of the injured nerve during surgical exploration can determine exact pathological changes. The presence of dorsal ganglion cells in the samples of the dorsal ganglion is a definitive evidence of root avulsion ( Fig. 36.24 ). Histopathological examination of fibrotic tissues, neuromas, and possible ganglia encountered during surgical exploration is noteworthy, both in terms of medicolegal aspects and in confirming the accurate levels of nerve reconstructions. ,
Clinical observation
Observation: The first 3 months.
Most children with birth palsy recover in the first 3 months, and about 70% of patients who do not require surgery show signs of recovery in the first 3 months. This is also what I observed in my patients. The first 3 months after birth is a recovery period, both for the baby and the parents ( Box 36.3 ). In these months, the family should be supported psychosocially, and physiotherapy should be started with an experienced physiotherapist ( Box 36.3 ). This should include passive joint motion exercises and neuromuscular electrical stimulation to denervated muscles.
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The end of the third month is important to make the decision for primary neural reconstruction.
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It is necessary to ensure that the denervation time is as short as possible.
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If there is still a total denervated muscles at the end of the third month, injury and recovery are evaluated by referring to magnetic resonance imaging and electromyography examinations.
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Satisfactory clinical results can be obtained if reconstruction of proximal roots with grafts for the muscles around the shoulder can be performed in the early period.
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In cases where there are two or more donor roots, the use of these roots in reconstruction may yield functional results.
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If there is one root donor or less, the contralateral C7 root can provide satisfactory healing as a donor in addition to the other donors.
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Customized approaches, including a combination of proximal reconstructions and distal nerve transfers, may be preferred at 6 to18 months of age.
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In neglected cases, limited gains can be achieved in late brachial plexus reconstructions.
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Transfer of the spinal accessory nerve to the suprascapular nerve or to the infraspinatus branch gives reliable results.
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Selective fascicular transfer from the median and ulnar nerves to the musculocutaneous nerve gives reliable results.
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Conditions are not always suitable in birth palsy for the transfer of triceps motor branches to the axillary nerve, as most children with weak deltoid muscles also have weak triceps muscles.
In severe cases, it may be beneficial to educate parents on the basic anatomical structures and basic physiology of nerve healing. This is because, in these severe cases, the treatment process can take years, and parental education on this issue provides great benefits.
The Active Movement Scale and modified Mallet scoring systems are generally accepted methods based on clinical assessment. They are practical methods for determining physical limitation, but they do not provide sufficient detail for strategic surgical decisions. Neuropraxia will heal within weeks.
Time taken for axons to enter the relevant muscles.
In cases with impaired axonal integrity, if the maximum time taken for axons to enter the relevant muscles from the intervertebral foramen is known, the maximum waiting time required for a muscle function to return can be determined. Based on our measurements of nerve length in cadavers, we estimate that, in a baby with an arm length of 130 mm, the deltoid reinnervation process is expected to start on the 88th day, the triceps on 94th day, the brachialis on 120th day, the pronator teres on 172nd day, and the extensor carpi ulnaris on 206th day, at the latest. The axonal recovery may be faster in infants and may not be as lengthy as noted here.
Clinically, most children (who do not need surgery) show signs of clinical recovery in the first 3 to 6 months, especially after C5 and C6 injuries. If signs of reinnervation are not observed (which is often the case in infants with C8 and T1 injuries because nerve disruption or avulsion of the C8 and T1 are more common) after this maximum waiting time (3–6 months) has elapsed, the reconstruction of the brachial plexus should be considered. In such cases, objective data should be obtained on recovery via MRI and EMG examinations. In addition to loss of lower trunk function, the presence of root avulsion findings in an MRI examination constitutes the strongest surgical indication.
Timing and indications for surgery
Timing of surgery: 3 to 6 months after birth.
The decision for surgical reconstruction of the brachial plexus is usually made 3 to 6 months after birth. To determine surgery, MRI and/or EMG examination is important and necessary. If MRI and EMG data also indicate that nerve integrity is impaired and there is no clinical sign of recovery, surgery is indicated.
Since secondary changes have already started in the muscles at 3 to 6 months of age, decisions made based on global movements may be incorrect. The stiffness and relative shortness of the subscapularis and pectoralis major muscles can interfere with the effective functioning of the supraspinatus and deltoid muscles. Likewise, a strong and rigid triceps muscle can prevent contraction of the elbow flexors from turning into functional movement. For this reason, I believe it is necessary to evaluate each muscle separately.
Babies with horner sign and sensory and motor loss in the hand.
Babies with Horner sign and sensory and motor loss in the hand are candidates for early surgical reconstruction. Damage to the C8 and T1 roots usually involves avulsion, and there is little chance of spontaneous recovery. Early reconstructions at 3 months will likely produce the best long-term results in our experience, although the age at surgery has recently increased. , Presumably, the advantages of nerve reconstruction in the early period are more pronounced for recovery of hand function. One study suggests that late surgical timing has a negative effect on hand-to-mouth movement, but no significant difference was observed in terms of shoulder function.
Babies with permanent denervation in the muscles around the shoulder.
If permanent denervation findings in the muscles around the shoulder remain at the end of 3 months of age, MRI and EMG examinations may be useful in determining the treatment strategy. If these examinations indicate nerve recovery is taking place, the observation-based period can be extended. If there are no signs of improvement, surgical reconstruction may be considered. There is a general belief that reconstruction of the brachial plexus with microsurgical methods provides functional gain in birth palsy, and the evidence of this has recently been increasing. If there is no sign of improvement in the first 6 to 9 months, the decision for surgery can be made more confidently. However, in this period, some functions in the shoulder and elbow may be weak and incomplete.
This is the group for which surgical decision-making is the most difficult. We see that patients with delayed recovery and insufficient progress have worse shoulder and elbow function than those with C5 and C6 reconstructions in the early period. In other words, if the C5, C6, and upper trunk are reconstructed in babies who did not improve at the desired level between 3 and 6 months of age, better clinical results can be obtained than those of patients who recover spontaneously. Since the result of surgery is not better than spontaneous recovery in every case, there is concern about losing existing function.
Surgery versus nonsurgery
Surgical indications for patients with birth palsy vary greatly in different centers worldwide, and there are very different views on surgical treatment versus nonsurgical treatment to allow for spontaneous recovery of function. Many surgeons operate on a very small subgroup of patients. Some do not believe nerve reconstruction improves function. Please refer to “ In-Depth Analysis ” and “ Further Information ” at the end of this section.
Surgical methods
Early brachial plexus reconstruction: 5 to 9 months after birth.
This surgery is usually performed at 5 to 9 months of age and after parents are informed of the extent of brachial plexus injury and postreconstruction expectations. Surgical tips are summarized in Box 36.4 . Distal nerve transfers have become increasingly popular in recent years. , They are an effective and relatively easy method in the period between 9 and 18 months of age in patients with insufficient elbow flexion and insufficient external shoulder rotation. , The clinical results of distal nerve transfers and proximal grafts are similar for gains in elbow flexion.
Surgical tips
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In brachial plexus exploration, it is essential to expose all roots, trunks, and emerging branches.
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For exploration at the proximal root level, resection of the already damaged scalenus anterior muscle provides a broader visualization.
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Exploration of the retroclavicular and infraclavicular parts of the brachial plexus can be done by extending the surgical field into the deltopectoral interval. Late problems are common in clavicular osteotomy.
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10-0 suture material is preferred for nerve repairs. Fibrin glue may be used to strengthen the neurorrhaphy.
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While determining the length of the nerve grafts, the distance between the nerve endings is maximized by keeping the neck in extension to the contralateral side and the upper extremity in traction toward the distal. In the grafts that are coapted in this position, tension is avoided in the postop period.
Nerve grafts are used to bridge any defects of the plexus found during exploration and are used when the nerve roots are intact. The techniques and donor sites, such as sural nerves for nerve grafting, are similar to those used for nerve defects in adults. Bilateral sural nerves and cervical plexus nerves are common donors. There is often a concern of availability of donor sites for multiple nerve defects.
During surgery, it is often necessary to determine with histological examination the level of healthy nerves and whether it is truly a pre- or post-ganglionic injury. This information aids in deciding the length at which the nerve should be resected and whether a nerve graft or nerve transfer can be used.
Below is a more detailed discussion on nerve transfers, as the donor sites vary. Transfer of the spinal accessory nerve to the suprascapular nerve , or to the infraspinatus branch can provide beneficial results ( Fig. 36.25 ). In a meta-analysis of four studies, transfer of the spinal accessory nerve to the suprascapular nerve yielded better results than grafting, and secondary problems were milder. In cases where the suprascapular nerve cannot be used, the dorsal scapular nerve can be transferred to the suprascapular nerve. It is not likely to have been damaged during delivery, as it exits the C5 root at a very proximal level ( Fig. 36.26 ).
Transfer of triceps motor branches to the axillary nerve may not always be possible in babies with birth palsy. This is because, in most babies with weak deltoid function, the triceps may also be weak. Neurotization of the elbow flexors with fascicles originating from the ulnar and median nerves is another method that provides good results.
It is critical to have an idea about the pathology and recovery potential of the proximal nerve roots during surgery. Samples can be taken for this purpose from nerves during surgery for quick histological examination. We conducted a somatosensory evoked potential study in a group of our patients. However, this method cannot be used in every case because the setup took a long time, and a neurophysiologist had to be involved throughout the surgery. However, we discovered that bispectral index analysis can be used for this purpose. This method is used by anesthesiologists to measure the level of anesthesia during surgery. If there is an increase in the level of alertness when the nerve root is stimulated, it is possibly uninjured proximally.
The most important fate-determining factor in reconstruction with nerve transfer is the availability of donor nerves. The C5 and C6 roots are usually available as donors in babies born with head presentation. If the C8 and T1 roots are intact, reconstruction of C5 and C6 roots and upper and middle trunks may provide the best clinical results ( Fig. 36.27 A). Even one of these roots may be sufficient for shoulder and elbow reanimation. Since birth palsy is a form of traction injury, and the distal and proximal nerve stumps diverge from each other in the growing baby, it is often necessary to use sural nerve grafts. Sural nerve grafts are usually taken using a traditional open technique to avoid damaging the nerve. However, it is also possible to take this nerve safely and effectively using an endoscopic technique. In this way, it is possible to use the operation time more efficiently and avoid long incisions.
In avulsions of C5, C6, and C7 roots, which are less often seen and mostly due to breech presentation or severe axial traction during birth, it is necessary to use extra-plexal donors for nerve transfers. The spinal accessory nerve, medial pectoral nerve, and intercostal nerves can serve as donors. In our experience, the contralateral C7 (CC7) root can also be used as a donor.
If there is damage to all roots and potential donor nerves are not available, we prefer the above-mentioned extra-plexal donors for shoulder and elbow functions , and the CC7 root for the lower trunk ( Fig. 36.27 B). However, we do not have enough information on donor site morbidity after these interventions in infants. There is a general concern among western surgeons regarding the influence on function of the donor sites (especially CC7) after these transfers in adults.
Nerve grafting can be used with nerve transfers, depending on the number of roots involved. Repair of the lower trunk can be prioritized, as motor recovery after lower trunk reconstructions is more difficult. In Toronto, Canada, Morrow et al. used the highest possible number of nerve grafts, such as bilateral sural nerves and cervical plexus nerves, for the best available proximal roots after all damaged elements of the brachial plexus were resected and frozen-section evaluation to examine the viability of the proximal and distal stump. These approaches can be used together with spinal accessory nerve or intercostal nerve transfers, when needed. They made the lower trunk the first priority to restore meaningful hand function. In their patients, if only one viable nerve root was available, at least four sural nerve grafts were used to connect that root to the entire lower trunk. If two roots were available, the largest root with the best histological quality was grafted to the lower trunk, and the other root was connected with a graft to the upper and middle trunks. If three roots were available, the best root was connected to the lower trunk with grafts, the next-best root to the upper trunk, and the third-best root to the middle trunk. They reported that hand function was restored to sufficiently perform bimanual activities in 21 out of 26 patients with complete birth palsy at 8 years of age. Their outcomes indicate that lower trunk reconstruction can result in a functional hand.
After upper and middle trunk reconstructions, motor recovery can occur to a larger extent than that after lower trunk reconstructions. In contrast, after lower trunk reconstructions, motor recovery in the hand is limited, although sensory recovery can be almost normal. Following brachial plexus reconstruction in infants, migration of axons toward target tissues may occur despite the long distance, and sensory recovery may be noteworthy. A reason for not reaching the desired motor function may be secondary changes in the muscles. Another reason the desired motor activity cannot be achieved, especially in the hand, may be that the cortical motor areas of the brain were severely altered prior to the axonal regrowth.
Late brachial plexus reconstruction: After 10 months of age.
In the later period, distal nerve transfers are popular when function cannot be regained. Oberlin and MacKinnon transfers can give consistent results for elbow flexion in infants with normal hand function. Transfer of the spinal accessory nerve to the suprascapular nerve or to the infraspinatus branch is also an effective method to acquire external rotation of the shoulder joint. Relatively late nerve transfers should not create a false sense of hope, and the opportunity for early reconstruction should not be lost, even though distal nerve transfer may be possible later.
Transfer of motor nerve branches innervating the triceps to the axillary nerve is a method that can be used in birth palsy, albeit limited. In birth palsy, unlike traumatic lesions in adults, if the deltoid is paralytic, the triceps is often weak ( Fig. 36.27 C). Transfer of the spinal accessory nerve to the infraspinatus motor branch and the triceps motor branch to the teres minor motor branch gives effective results in children older than 18 months.
Neural reconstruction should be performed before the changes in the target structures of the denervation become permanent. It seems possible, however, to obtain modest recovery in the shoulder and elbow function in the brachial plexus when reconstruction is performed at an average of 15 months. Despite this, it is necessary to judge the patient clinically and to avoid unnecessary delays.
In early or late nerve reconstructive surgery, if the brachial plexus injury extends to the retroclavicular or infraclavicular level, clavicular osteotomy provides a wide exposure, and coaptation of the nerve grafts under the microscope can be made more easily. However, healing of a clavicular osteotomy can be quite problematic, and the procedure may be avoidable. If retroclavicular and infraclavicular repair is required, grafts are coapted distally through the deltopectoral interval. Then, the nerve grafts are passed under the clavicle, brought proximally, and coapted to the donor nerves. If exploration of the T1 root and lower trunk is required, sternoclavicular dislocation may also be useful ( Fig. 36.28 ).
