Congenital Pseudoarthrosis of the Clavicle (Pediatric)

Synonyms
Congenital pseudarthrosis of the clavicle 

INTRODUCTION

Definition

Congenital failure of formation of the central portion of the clavicle that manifests as a painless lump in the clavicle.

Epidemiology

  • Bilateral in less than 10% of cases.
    • Familial incidence is reported in some patients, particularly in bilateral cases.
  • Involves the right clavicle most often. Located on left side with dextrocardia (situs inversus).
  • No association with neurofibromatosis. Birth trauma plays no role in this condition. 
  • The incidence of associated cervical ribs is 15%.

Etiology

It may be related to abnormalities in aortic arch angiogenesis and pulsations of the underlying subclavian artery during the process of development of the clavicle. 

Pathogenesis

Occurs due to failure of union between medial and lateral ossification centers of clavicle.

Differential Diagnosis

  • Clavicular fracture: Seen among toddlers and children. Majority (80 %) of clavicle fractures occur in midshaft. Clavicle fractures will be expected to heal on their own, unlike congenital pseudoarthrosis. 
  • Cleidocranial dysplasia

CLINICAL FEATURES

Symptoms

Usually no symptoms. Functional impairment is uncommon in children but it may become painful with some activities that involve movements above head. The deformity tends to become more obvious with the child’s growth. 

Signs.

Inspection: Enlarging mass. It may be associated with winging of scapula.
  • The pseudoarthrosis is fully present at birth.
  • The larger sternal fragment is tilted upward and lies in front of and slightly above the medial end of the smaller acromial portion.
Palpation: Painless and nontender.
Movement/ROM: There is a variable degree of painless mobility between the fragments. 

DIAGNOSIS

X-ray

Projections: Anteroposterior (AP) view of the clavicle.
Findings: Rounded sclerotic ends of two fragments at the pseudarthrosis site and lack of callous formation.

TREATMENT

Overview

Typically congenital pseudoarthrosis of the clavicle causes little discomfort and requires no treatment.

Nonoperative Treatment

Indication: Minimal symptoms and cosmetic deformity.
Method: Observation.

Operative Treatment

Indication: Cosmesis, functional impairment och pain. Surgery is very uncommon.
Method: Open reduction and internal fixation (ORIF) with iliac crest bone grafting at age 3-6 years.
Outcome: Usually successful union. Observe that bone graft substitute has higher rates of non-union.
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References