Which abnormalities on the assessment of a newborn are seen when a clavicle is fractured in the birthing process?

Birth Trauma

Birth trauma should be considered a possible cause when a child with a fracture is seen during the first few weeks of life. Clavicular fractures are the most common fractures related to birth trauma. Fractures missed in the delivery room or nursery are frequently found incidentally on chest radiographs or when palpable callus is noted by the parents.17a The humerus is the most commonly fractured long bone in birth trauma, and these fractures usually involve the midshaft.17a Long bone fractures of the lower extremities occurring during birth are often seen in association with neuromuscular disease or bone abnormality,17a,24 whereas epiphyseal fractures are most commonly associated with breech delivery.17a Rib fractures from birth trauma are rare,17a and rib fractures found incidentally, without a history of severe trauma, are usually due to abuse. Callus develops in birth fractures within 2 weeks,17a,24 and lack of callus formation after this time interval strongly suggests that the injury did not occur during delivery.

Epidemiology

Obstetrical brachial palsy is not very frequent in children and there are important differences in the rate of occurrence among epidemiological studies. The incidence ranges from 0.05 to 0.145% and concerns the right upper limb in two out of three cases (Gilbert et al., 1999). The incidence is almost equally distributed among males and females. The most significant risk factor is high birth weight over 4 kg (Fig. 98.1), particularly in vertex presentation. The high birth weight is often associated with shoulder dystocia, an emergency when the anterior shoulder becomes impacted under the mothers’ pubic symphysis, increasing the frequency of obstetrical brachial palsy (Evans-Jones et al., 2003). In case of breech delivery, risk is increased by prematurity and state of apparent death by lack of muscle tone.

Maternal risk factors include diabetes mellitus, obesity, or excessive weight gain and primiparity in case of vertex presentation (Mollberg et al., 2005). Cesarean section does not obviate the risk of brachial plexus palsy, which depends, in fact, on the strength of manipulations (Evans-Jones et al., 2003).

Birth Injury

Birth injury, including shoulder dystocia (Keller et al, 1991) and brachial plexus trauma, is more common among IDMs, and macrosomic fetuses are at the highest risk (Mimouni et al, 1992). Shoulder dystocia, defined as difficulty in delivering the fetal body after expulsion of the fetal head, is an obstetric emergency that places the fetus and mother at great risk. Shoulder dystocia occurs in 0.3% to 0.5% of vaginal deliveries among normal pregnant women; the incidence is twofold to fourfold higher in women with diabetes, probably because the hyperglycemia of diabetic pregnancy causes the fetal shoulder and abdominal widths to become massive (Nesbitt et al, 1998). Although half of shoulder dystocias occur in infants of normal birth weight (2500 to 4000 g), the incidence of shoulder dystocia is 10-fold higher (5% to 7%) among infants weighing 4000 g or more and rises to 31% for infants whose mothers are diabetic (Gilbert et al, 1999). (See also Chapter 15 for discussion of complicated deliveries and Chapter 64 for discussion of the neurologic consequences of birth injury.)

IV. OBSTETRIC PALSY

Birth Trauma

Birth injury is defined as any condition that adversely affects the fetus during delivery (Gresham, 1975). Injuries may result from compression and traction forces during the birth process, malpresentation, a difficult prolonged labor, and large fetal size. Today, birth trauma is the cause of 2% of neonatal deaths and stillbirths in the United States (Gresham, 1975). Although any bone may be injured, the most typical fractures occur to the clavicle, humerus, proximal femur, and cranium (Brill and Winchester, 1987; Caffey, 1945; Resnick and Goergen, 2002). Clavicle fractures are frequently found in normal deliveries (i.e., 0.2%–2.9% of live births) and are considered to be unpreventable, often healing without any adverse effects (Ahn et al., 2015). Dedick and Caffey (1953) reported fractured clavicles in 1.2% of their 1030 newborns, these were always unilateral and occurred more commonly on the left side. Identifying cranial fractures as a result of birth injury presents more of a challenge for the paleopathologist due to the fragile and fragmentary nature of the perinatal cranium. Linear and depressed fractures may not survive fragmentation in the ground, and if the child dies shortly after birth, perimortem fractures may be indistinguishable from postmortem breaks. In medieval England, the use of a crochet to extract a child from the womb (Eccles, 1977, 1982) may have resulted in perimortem cut marks to the orbits and palatine surface of the maxilla. From the mid-16th century, forceps may have caused crush and linear fractures to the frontal, parietal, or occipital bones (Rushton, 1991) resulting in a hematoma (cephalhematoma) (Sorantin et al., 2006). Caffey (1945) described such injuries as positioned away from midline, a detail that may aid in their differentiation from a congenital meningocele. Ossified hematomas may persist for months or years (Fig. 5.23). The maxilla is also a frequent site for infection in the first few weeks of life due to birth trauma and may be visible as reactive new bone formation around the developing dental germs (Caffey, 1945). New bone formation around erupting teeth and on the cranium is also a sign of scurvy and should be considered as a differential diagnosis. In addition to fractures, breech delivery may cause trauma to the muscles and other soft tissues of the back and lower limbs. Severe muscle damage can result in crush syndrome and be fatal to the child (Ráliš, 1975). Damage to the sternomastoid muscle during birth may result in facial asymmetry, or torticollis, which will cause frontal and occipital flattening, a laterally twisted face, dropped orbit, an enlarged mastoid process, and mandibular asymmetry (Skinner et al., 1989).

A healed clavicle fracture in a 4-month-old from Christ Church Spitalfields, London has been interpreted as possible birth trauma (Lewis, 2002b), with four other cases of fractured clavicles reported in infants from England and Italy (Fig. 5.24; Brickley, 2006a; Soren et al., 1995; Verlinden, 2015). Baxarias et al. (2010) identified a healing linear fracture above the left orbit in a 38-week-old infant, suggesting birth trauma caused the injury. In a similar case, Polo-Cerdá et al. (2003) suggested the use of forceps during a basiotripsy as the cause of a perimortem linear cut marks on the parietal and occipital bones of a perinate from 18th-century Castielfabid, Spain. It is not known if the child was dead prompting this procedure or died during this violent extraction process. Soft tissue injuries during birth have also been suggested by Holst (2004), who identified a case of disuse atrophy in the right femur of a 2- to 4-month-old child from Bridlington, UK, which she suggested may have occurred at birth. Skinner et al. (1989) discussed cranial asymmetry from muscular torticollis as the result of breech births in three adult crania from British Columbia. Changes to the distal aspect of the humerus in the tiny remains of a perinate from St Oswald’s Priory have been interpreted as an oblique physeal fracture, with posterior displacement of the cartilaginous epiphyses, an injury likely sustained during the birth process (Fig. 5.25; DeLee et al., 1980; Verlinden and Lewis, 2015).

Birth Injury

Birth injury, including shoulder dystocia (Keller et al, 1991) and brachial plexus trauma, is more common among IDMs, and macrosomic fetuses are at the highest risk (Mimouni et al, 1992). Shoulder dystocia, defined as difficulty in delivering the fetal body after expulsion of the fetal head, is an obstetric emergency that places the fetus and mother at great risk. Shoulder dystocia occurs in 0.3% to 0.5% of vaginal deliveries among normal pregnant women; the incidence is twofold to fourfold higher in women with diabetes, probably because the hyperglycemia in a diabetic pregnancy causes the fetal shoulder and abdominal widths to become massive (Nesbitt et al, 1998). This relationship was investigated by Athukorala et al, (2007), who found a strong association with fasting hyperglycemia such that with each 1-mmol increase in the fasting value in the oral glucose-tolerance test there was an increasing relative risk (RR) of 2.09 (95% confidence interval [CI], 1.03 to 4.25) for shoulder dystocia. Although half of shoulder dystocias occur in infants of normal birthweight (2500 to 4000 g), the incidence of shoulder dystocia is 10-fold higher (5% to 7%) among infants weighing 4000 g or more and rises to 31% for infants whose mothers have diabetes (Gilbert et al, 1999; see also Chapter 15 for a discussion of complicated deliveries and Chapter 64 for a discussion of the neurologic consequences of birth injury.)

Clinical manifestations

Birth trauma was formerly thought to be the cause of many neonatal chylothoraces, but the increasing use of prenatal ultrasonography has changed this perspective. Noniatrogenic chylothorax occurring in young children is usually related to congenital anomalies of the chyliferous vessels, cisterna chyli, or the thoracic duct itself. Most of these chylothoraces result from intrapleural leakage from dilated and thin-walled intercostal, diaphragmatic, or accessory mediastinal lymphatics. When there is lymphatic overload, these alternate lymphatics may dilate considerably to eventually become transudative lymphatic varices. In other cases, subpleural lymphatics may rupture into the pleural cavity, as in certain cardiac anomalies (e.g., total anomalous pulmonary venous return).

The accumulation of chyle in the pleural space from a thoracic duct leak may occur rapidly and produce pressure on other structures in the chest, causing acute respiratory distress, dyspnea, and cyanosis with tachypnea. In the fetus, a pleural effusion may be secondary to generalized hydrops but a primary lymphatic effusion (idiopathic, secondary to subpleural lymphangiectasia, pulmonary sequestration or associated with syndromes, such as Down, Turner, and Noonan) can cause mediastinal shift and result in hydrops or lead to pulmonary hypoplasia.244,245 Postnatally, the effects of chylothorax and the prolonged loss of chyle may include malnutrition, hypoproteinemia, fluid and electrolyte imbalance, metabolic acidosis, and immunodeficiency.257

In a neonate, symptoms of respiratory embarrassment observed in combination with a pleural effusion strongly suggest chylothorax. The involved side presents characteristic findings of intrapleural fluid with respiratory lag, dullness on percussion, diminished breath sounds, and shift of the mediastinum. Fever is not common. Chest roentgenograms typically show massive fluid effusion in the ipsilateral chest with pulmonary compression and mediastinal shift. Bilateral effusions may also occur. Aspiration of the pleural effusion reveals a clear straw-colored fluid in the fasting patient, which becomes milky after feedings. Analysis of the chyle generally reveals a total fat content of more than 400 mg/dL (or triglyceride level greater than 110 mg/dL) and a protein content of more than 5 g/dL. In a fetus or a fasting neonate, the most useful and simple test is to perform a complete cell count and differential on the fluid; when lymphocytes exceed 80% or 90% of the white blood cells, a lymphatic effusion is confirmed; the differential can be compared with that obtained from the blood count, where lymphocytes rarely represent more than 70% of white blood cells.

Most cases of traumatic chylothorax develop after thoracic operations, in particular, surgery for congenital heart disease.247 Injury to the thoracic duct in the left chest is also common during secondary thoracotomies for correction of lesions in the descending aorta or esophagus just inferior to the arch. If lymphatic drainage is noted at operation, the proximal and distal ends of the thoracic duct should be ligated.258 A period of days or weeks may elapse between trauma or surgery and the development of a symptomatic chylothorax.

As chyle accumulates in the pleural space from a thoracic duct leak, progressively more pronounced respiratory symptoms develop as pulmonary compression becomes more severe. Dyspnea, tachypnea, and, eventually, arterial desaturation with cyanosis can develop. Nutritional deficiency is a late manifestation of chyle depletion and occurs when dietary intake is insufficient to replace the thoracic duct fluid loss.

Obstetric Trauma

Birth trauma can be divided into two categories: fractures and neurologic injuries. Birth fractures most commonly involve the clavicle, with clavicular fractures occurring in 2 per 1000 to 35 per 1000 vaginal births (Sanford, 1931; Farkas and Levine, 1950; Cohen and Otto, 1980; Kaplan et al., 1998). Birth fractures also occur in the proximal part of the humerus (Broker and Burbach, 1990; Fisher et al., 1995), the femur (0.13 per 1000 births) (Morris et al., 2002), and even the thoracic spine. It is important to note that clavicular fracture can be seen in combination with a proximal humeral physeal separation or in combination with a brachial plexus injury. Reported risk factors for upper extremity birth fractures include large size of the baby, limited experience of the obstetrician, and a midforceps delivery (Cohen and Otto, 1980). Risk factors for femoral fracture include twin gestation, breech presentation, prematurity, and osteoporosis (Morris et al., 2002). Nadas et al. (1993) have reported an association of long-bone fractures with cesarean delivery, breech delivery with assistance, and low birth weight.

The natural history of isolated birth fractures to the extremities is that of uneventful rapid healing without untoward sequelae. Clavicle fractures may be difficult to diagnose, because the neonate may be asymptomatic. In a study of 300 newborns, radiographs revealed five unsuspected clavicle fractures (Farkas and Levine, 1950). Newborns with either a clavicle fracture or a proximal humeral physeal separation often have pseudoparalysis of the upper extremity. Considerations in the differential diagnosis include an obstetric brachial plexus palsy and hematogenous metaphyseal osteomyelitis of the humerus with septic glenohumeral arthritis. Pain with direct palpation of the clavicle may be present with obvious deformity. Pain with motion of the shoulder joint and with palpation of the proximal part of the humerus may be caused by either fracture or infection. Elicitation of neonatal reflexes such as the Moro reflex and asymmetric tonic neck reflex (ATNR) may be helpful in evaluating active upper extremity muscle function (Sanford, 1931). Radiographs should be obtained. Ultrasound evaluation of the proximal part of the humerus may be helpful because the proximal humeral epiphysis is entirely cartilaginous at birth and therefore radiolucent. Ultrasound examination can detect proximal physeal separation, metaphyseal osteomyelitis, and septic shoulder arthritis (Broker and Burbach, 1990; Fisher et al., 1995).

Asymptomatic birth fractures of the clavicle and humerus in neonates can be observed. The fracture will unite in short order, with remodeling of bone occurring with growth. Symptomatic fractures in which the child exhibits pseudoparalysis of the upper extremity should be treated with 7 to 10 days of immobilization in a soft dressing or until symptoms subside. Femoral birth fractures can be treated with a Pavlik harness with good results (Morris et al., 2002). This device provides a simple means of immobilization that is accepted well by new parents. Excellent outcomes with no residual deformities or limb length inequalities can be expected.

The presence of multiple long-bone and rib fractures at birth may herald the presence of OI. Prenatal diagnosis is commonly made by ultrasonographic screening, as early as 13 to 14 weeks' gestation, on the basis of deformity (Cheung and Glorieux, 2008). OI is typically classified by the Sillence classification, with type II and type III being the most common types identified in the perinatal period (Sillence et al., 1979). Type II OI is lethal in the neonatal period, whereas most children with type III OI survive into adulthood with considerable short stature and fracture-related morbidity. Thus prompt genetic consultation is critical to establish a diagnosis and prognosis for an affected child. A diagnosis of Bruck syndrome should be considered when clinical and radiographic findings of OI are coupled with joint contractures (Schwarze et al., 2013). Infants with type III OI often require substantial respiratory support and pain management because of rib fractures, with respiratory failure being identified as the most common cause of death in the neonatal period. Treatment of long fractures is primarily to support pain management and can be achieved by custom splints or merely soft supports, such as pillows or blankets. Patients with multiple fractures at birth who are expected to survive the neonatal period should be considered for bisphosphonate treatment (Shapiro and Sponsellor, 2009).

Brachial plexus injuries represent the second category of birth trauma afflicting newborns. The mechanism of injury is a separation of the head from the shoulder by lateral bending of the neck with simultaneous shoulder depression during vaginal delivery resulting in a stretching of the brachial plexus. These injuries occur in 1 per 1000 to 4 per 1000 live births (Hardy, 1981; Greenwald et al., 1984). Risk factors include maternal diabetes, large birthweight, prolonged labor, forceps delivery, and shoulder dystocia during a vertex delivery (Piatt, 2004). They are rarely seen in cesarean deliveries. Brachial plexus palsies are associated with clavicle and humerus fractures, as well as torticollis.

The brachial plexus receives contributions from the anterior spinal nerve roots of C5 through T1, which combine and divide to form the peripheral nerves that supply the motor innervation to the upper extremity. Three major injuries are encountered. The most frequent injury is to the upper trunk that involves the C5 and C6 nerve roots primarily and results in an Erb palsy. Affected infants lack external rotation and abduction of the shoulder. Hand function is preserved. The next most frequently occurring injury is a global plexus palsy involving the C5 through T1 nerve roots. This results in flaccid paralysis of the involved upper extremity, including the hand. An isolated lower plexus injury involving the C8 and T1 nerve roots, termed Klumpke palsy, is the least common and may be a manifestation of a recovered global plexus injury (Waters, 1997).

The physical examination has proved to be the most reliable method of assessing the level and severity of the neural injury and thereby predicting the potential for spontaneous recovery (Waters, 1997; Noetzel et al., 2001). Myelography, computed tomographic myelography, magnetic resonance imaging, and electrodiagnostic studies have not proved useful in predicting recovery (Waters, 1997). Active shoulder, elbow, wrist, and finger motion need to be assessed (Piatt, 2004). Frequently, such assessment can be facilitated by elicitation of the primitive reflexes that are transiently present in normal newborns. The hand grasp reflex is normal in all newborns and disappears between 2 and 4 months. The examiner's little finger is placed on the ulnar aspect of the infant's palm, and the infant's fingers reflexively flex and grasp the examiner's finger. The Moro reflex begins to fade at 3 months of age. It is elicited by the examiner holding the newborn's hands while raising the baby off the table and then suddenly releasing them. In response, the newborn extends the spine, abducts and extends all four limbs and digits, and then subsequently adducts and flexes the limbs and digits. Last, the ATNR, or fencing reflex, can be elicited in a normal newborn until the age of 4 months. With the infant lying supine on an examining table, the head is rotated to one side by the examiner. The infant should respond by extending the elbow on the side toward which the face is looking and by flexing the opposite elbow. In newborns with a brachial plexus injury, some of these reflexes will be abnormal because of lack of motor control. For instance, the newborn with an Erb palsy will, most notably, not be able to actively flex at the elbow during the ATNR or the Moro reflex. The presence or absence of Horner syndrome (contracted pupil, drooping eyelid, and decreased sweating on the affected side) must also be noted.

An affected infant needs repeated serial examinations until 6 months of age. Return of biceps function by 3 months is the most important indicator of brachial plexus recovery (Michelow et al., 1994). When biceps recovery is combined with the return of shoulder abduction, wrist extension, and finger extension, there is a 95% chance of normal function (Michelow et al., 1994). When biceps function recovers later than 3 months, it is rare for the child to have complete recovery of normal function (Waters, 1999). A total plexus palsy or the presence of Horner syndrome also heralds a poor prognosis (Michelow et al., 1994; Waters, 1997).

The initial treatment of obstetric brachial plexus injury is aimed at avoiding contractures of the shoulder, elbow, forearm, and hand with occupational or physical therapy during the observation-for-recovery phase. Fortunately, as few as 1 in 10 infants with brachial plexus palsies at birth will require surgical intervention (Piatt, 2004). With the decision for surgery being based on muscle function recovery, prompt referral to a specialist is recommended to initiate monthly neurologic examinations.

Brachial plexus exploration with subsequent reconstruction is indicated for infants with total plexus involvement, Horner syndrome, and no return of biceps function at 3 months and for infants with a C5 to C6 (Erb) plexopathy and no return of biceps function at 3 to 6 months (Waters, 1997). Surgery is undertaken between 3 and 6 months of age. Using this algorithm prospectively, Waters (1999) operated on six infants at 6 months and found that their results were better than those for the 15 patients with biceps recovery at 5 months but worse than those for the 11 patients with biceps recovery at 4 months. Despite treatment as outlined, some children will have residual deficits. Secondary reconstruction, for chronic brachial plexopathy resulting in a dysfunctional shoulder, can be achieved with a tendon transfer of the latissimus dorsi and teres major to the rotator cuff or by derotational osteotomy of the humerus. These procedures and others designed to correct limitations in hand and forearm function are undertaken after the true scope of the disability has been assessed. A more recent study suggested that some infants with no biceps recovery by 3 months will eventually achieve adequate biceps and shoulder function without surgery (Smith et al., 2004). The optimal timing of surgical intervention remains controversial. Surgical exploration after 18 months is of little benefit.

Congenital Nasal Stenosis

With birth trauma, the nasal septum may become buckled or, less commonly, dislocated. Most cases respond to decongestant and steroid nasal drops, but dislocations require surgical manipulation (Presscott, 1995).

Nasal congestion may be associated with congenital syphilis, viral infection, maternal reserpine ingestion, and maternal fluphenazine ingestion.

Nasal pyriform aperture stenosis is characterized by excessive bone formation in the nasal processes of the maxillary bone; manifestations include severe obstruction and difficulty in passing a catheter. Because the newborn is a preferential nasal breather, an oral airway may be necessary to relieve the breathing difficulty. The obstruction is best demonstrated by computed tomography (CT) scan (Truong and Oudjhane, 1994). In most cases, the problem is resolved with nasal drops, but in more severe cases, surgery to remove excessive bone and nasal stenting are required. The condition may be associated with a solitary maxillary central incisor tooth; in other cases there may be more serious problems, including midline defects such as pituitary hypoplasia with endocrine insufficiency (Beregszaszi et al, 1996), diabetes insipidus (Godil et al, 2000), other manifestations of holoprosencephaly, and craniosynostosis (Van den Abbeele et al, 2001).

Nasal hypoplasia has been associated with warfarin embryopathy. In some newborns a nasolacrimal duct cyst may cause nasal obstruction.

Postischemic Dystonia

Dystonia after birth injury occurs in two settings. Children with early evidence of motor and intellection developmental delay may have early chorea or athetosis (writhing postures) which convert to dystonia later. In addition, there is a syndrome in which children survive birth injury without stigma but develop pure dystonia later in childhood. This dystonia may worsen for decades. The MRI in these cases is often normal or shows only generalized atrophy. The phenomenology of dystonia after ischemic stroke or hemorrhage in adult life divides into two groups: fixed postures (sometimes with pain) and posturing with superimposed tremor or writhing movements. The kinetic form of dystonia after ischemic injury usually involves lesions of the thalamus. The pain may be a combination of central (thalamic) pain and peripheral pain from muscle spasm. Surprisingly, dystonia arising after ischemic injury early in life may improve with the same medicines that treat primary dystonia, but postischemic dystonia arising in adult life is very difficult to treat. Pain arising from muscle spasm responds to BTX injections. The efficacy of pallidal DBS in postischemic, adult onset dystonia is not clear.