JANUARY 2022 Question: A two-hour-old term neonate has decreased movement of her left arm in the newborn nursery. Her mother’s pregnancy was complicated by obesity and gestational diabetes. She was delivered vaginally with vacuum assistance. Agape scores were eight and nine at one and five minutes, respectively. She weighs 4.6 kg. Physical examination findings are notable for a comfortable-appearing, macrosomic neonate with left posterior cephalohematoma, no crepitus of the clavicle, absent left Moro reflex, no movement against gravity of the left arm, positive left hand grasp, and active movement of the right arm and lower extremities. Sensation appears intact in all extremities. The remainder of the physical examination findings is normal. Look at the chest radiograph: Of the following, the BEST next step in management of this neonate is A. left arm immobilization B. left arm muscle biopsy C. nerve condition studies D. physical therapy consultation Answer: Based on the chest radiography findings, the neonate in this vignette has a left humeral fracture likely sustained during birth. She is not moving her left arm because of pain, not neurologic injury. The next best step in management is immobilization of the left arm at 90 degrees. Long bone fractures involving the humerus and femur are not rare findings and occur more often with breech presentation. Additional risk factors and clinical features of humerus and femur fractures in the neonate are listed below. Fractures of the humerus heal quickly and rarely require additional therapy. They should be evaluated by a pediatric orthopedist on an outpatient basis.
FEATURES of HUMERUS and FEMUR FRACTURES Feature
Humerus Fracture
Femur Fracture
Incidence
0.12 per 1,000 deliveries
0.13 per 1,000 deliveries
Risk factors
Shoulder dystocia, cesarean delivery, macrosomia, breech presentation, low birth weight
Twin pregnancies, breech presentation, prematurity, diffuse osteoporosis
Clinical features Decreased arm movement, ocalized crepitus, pain with palpation
Asymptomatic or pain response to handling, “pop” or “snap” on delivery
Diagnostic modality
Radiography
Radiography
Treatment Immobilization with elbow in 90 degrees
Pavlik harness is an optional treatment in newborns
Prognosis
Outcome is excellent
Outcome is excellent.
(Reprinted with permission from Akangire G., Carter B. Birth injuries in neonates. Pediatr Rev.2016;37:460)
The incidence of birth trauma has decreased over the past 40 years. In 1981, birth injury was the sixth most common cause of neonatal death (23.8 deaths per 100,000 live births). In 1993, with changes in obstetric practice and increased use of caesarean delivery rather than complicated vaginal deliveries, mortality from birth injury decreased to 3.7 deaths per 100,000 live births. Risk factors and commonly associated birth injuries are listed below: RISK FACTORS for BIRTH TRAUMA and ASSOCIATED INJURY Risk Factors
Related Injuries
Forceps delivery
Facial nerve injuries
Vacuum extraction
Depressed skull fracture, subgaleal hemorrhage
Forceps/vacuum/forceps and vacuum
Cephalohematoma, intracranial hemorrhage, shoulder dystocia, retinal hemorrhages
Breech presentation
Brachial plexus palsy, intracranial hemorrhage, gluteal lacerations, long bone fractures
Macrosomia
Shoulder dystocia, clavicle and rib fractures, cephalohematoma, caput succedaneum
Abnormal presentation (face, Excessive bruising, retinal hemorrhage, lacerations brow, transverse, compound) Prematurity
Bruising, intracranial and extracranial hemorrhage
Precipitous delivery
Bruising, intracranial and extracranial hemorrhage, retinal hemorrhage
(Reprinted with permission from Akangire G., Carter B. Birth injuries in neonates. Pediatr Rev.2016;37:452)
Brachial plexus injury is caused by swelling of the nerve sheath surrounding cervical nerve roots and is more commonly associated with a breech delivery. It typically is a transient injury. The clinical presentation varies based on the involved nerve roots. Neonates with brachial plexus injury should be referred for physical therapy to optimize range of motion and muscle strength. Nerve conduction studies and a muscle biopsy are sometimes indicated to diagnose peripheral neuropathy or myopathy. This is most unlikely given the localized findings of decreased left arm movement seen in the neonate in the vignette.