Shoulder Dislocation in a Neonate

Labor was induced at term in a 29-year-old woman who had had an uneventful pregnancy. Her baby weighed 3575 g (7 lb, 14 oz).

The neonate’s left arm was internally rotated with flexion at the wrist. He had a normal grasp reflex, but Moro reflex was incomplete. No bony crepitus or swelling was noted along the clavicles; however, the head of humerus was easily dislocated inferiorly and posteriorly resulting in a very lax shoulder joint. Compared with the right side, the left shoulder appeared flattened. There was very little spontaneous movement on the left upper extremity but no apparent loss of sensation. The rest of the physical examination was normal. A clinical diagnosis of Erb-Duchenne palsy with shoulder dislocation was made. Because a modicum of spontaneous movement was retained, this was considered a neuropraxia.

AP (Figure 1) and lateral (Figure 2) radiographic views of the shoulders showed that the left humeral head did not project on the glenoid fossa, a finding suggestive of joint subluxation or dislocation. No soft tissue swelling and the osteochondral surfaces were smooth, with no bony lesion or fracture.

Figure 1

The left arm was splinted across the chest with the elbow flexed. The infant was discharged home within 48 hours and was referred to a pediatric orthopedic surgeon. Examination after 1 week revealed some improvement in function and in laxity of the shoulder joint although left arm abduction was limited to 90 degrees and wrist flexors and extensors showed residual weakness. A probable diagnosis of shoulder dislocation secondary to brachial plexus injury was made and conservative treatment under careful monitoring was favored. The infant was referred for occupational and physical therapy (OT/PT) where the focus was on strengthening, increasing range of motion, and flexibility exercises. The splint was replaced by Kinesio taping for neuromuscular re-education. Family education was provided as well. By the 4-month well-child visit, there was complete resolution of palsy with full function and OT/PT intervention was discontinued.

Figure 2

Discussion
Dislocation of a shoulder joint at birth is extremely rare and is the result of traumatic birth injury, brachial plexus injury, or true congenital dislocation developed in utero with no associated injury.¹ The estimated incidence of true congenital dislocation is 0.018% to 0.07%.² Shoulder dislocation secondary to brachial plexus injury, as seen in our patient, has been well described^3-6 and is the most common type. Traumatic physeal fracture of the proximal humerus could be associated with a posterior dislocation and mistakenly be diagnosed as a true congenital dislocation.

A shoulder dislocation at birth may be initially overlooked for several reasons. It is a rare event and therefore not immediately considered when signs and symptoms are first noted. Associated brachial plexus palsy and a difficult delivery may distract attention from the gleno-humeral joint as a source of these symptoms. Because the humeral head is not fully ossified at birth, the anomaly may go unnoticed on routine radiographs unless an index of suspicion has been established. Sequelae of a missed diagnosis may include contractures and recurrent dislocations.

Early and aggressive treatment is essential and associated with positive outcomes.⁷ Passive motion must be maintained to ensure the development of a congruent gleno-humeral joint. As ossification of the glenoid and humerus proceeds, the shoulder joint begins to take on its permanent shape which is typically reached by 3 years of age. Without physical therapy to maintain external rotation and concentric location of the joint, surgical intervention will most likely be required when the joint matures to avoid joint incongruence and permanent loss of motion.⁸

Given the rarity of the condition, surgical options are few and not well described. Active conservative management is preferred where possible. Surgery may have been an option in the case of our patient if satisfactory improvement had not been seen after 3 to 4 months of therapy.

Signs and symptoms of an undetected dislocation include decreased spontaneous use of the arm and increased tone and/or decreased range of motion. A comprehensive well-child examination that includes a complete neurologic history and exam, including history of birth-related events, should detect this condition.

Teaching Points
  • The most common type of birth-related shoulder dislocation is associated with brachial plexus injury. Although it is rare, this condition should be kept in mind while examining newborns.

  • Examination for evidence of birth trauma should be an integral part of newborn examination in the nursery. Key elements include palpation of the clavicle, evaluation of shoulder joint including range of movement, assessment for symmetry of spontaneous movements of extremities.

  • Presence of crepitus, deformity, flattening of the shoulder or soft tissue swelling in the area should alert the clinician to possibility of more severe injuries.

References:

References 

1. Whitman R. The treatment of congenital and acquired luxations at the shoulder in childhood. Ann Surg. 1905;42:110–115.

2. Schmelzer-Schmied N, Ochs BG, Carstens C. Shoulder dislocation in the newborn: report of 12 cases and review of the literature. Orthopade. 2005;34:454–461.

3.  Taylor AS. So-called congenital dislocation of the shoulder, posterior subluxation. Ann Surg. 1921;24:368–375.

4.  Liebolt FL, Furey JG. Ostetrical paralysis with dislocation of the shoulder. J Bone Joint Surg Am. 1953;35:227–230.

5.  Wickstrom J, Haslam ET, Hutchinson RH. The surgical management of residual deformities of the shoulder following birth injuries of the brachial plexus. J Bone Joint Surg Am. 1955;37:27–36.

6.  Babbitt DP, Cassidy RH. Obstetrical paralysis and dislocation of the shoulder in infancy. J Bone Joint Surg Am. 1968;50:1447–1452.

7.  Sudesh P, Rangdal S, Bali K, et al. True congenital dislocation of shoulder: A case report and review of the literature. Int J Shoulder Surg. 2010;4:102–105.

8. Price A, Tidwell M, Grossman JA. Improving shoulder and elbow function in children with Erb’s palsy. Semin Pediatr Neurol. 2000;7:44-51.