Congenital Pseudarthrosis of the Clavicle: A Case Report and a Hypothesis for the Right-Side Predominance

Abstract

Congenital pseudarthrosis of the clavicle (CPC) is rare. It predominantly affects the right side for an unknown reason. Most of the reported cases are diagnosed outside the neonatal period. Only two CPC cases have been reported in Saudi Arabia, where both were diagnosed during childhood. Here, we present the case of a Saudi male newborn with right-sided CPC. The diagnosis was made shortly after birth because of the uneventful cesarean delivery and painless clavicular lump. Fetuses prefer keeping their head in a right lateral position which may be a plausible explanation for the right-side predominancy in the CPC.

Serendipitous Discovery: A Case of Twin Congenital Pseudarthrosis of the Clavicle in Saudi Arabia and Literature Review

“…CPC is triggered by the failure of the union process of the ossification nuclei of the clavicle [4,5]. The first ever documented case was in 1910 by Fitzwilliams, and currently, CPC stands as an exceptionally uncommon congenital shoulder girdle deformity, with around 323 global cases documented [4,6,7]. Initially, there was an assumption that CPC was more frequent in females compared to males [3,7].…”

“…Nevertheless, subsequent observations indicated an equal ratio of males to females at 1:1 [5]. On the other hand, it predominantly affects the right side for unknown reasons [6]. Only three CPC cases have been reported so far in Saudi Arabia and were diagnosed during childhood [6,8,9].…”

“…On the other hand, it predominantly affects the right side for unknown reasons [6]. Only three CPC cases have been reported so far in Saudi Arabia and were diagnosed during childhood [6,8,9]. Patients usually present early in childhood with a painless swelling over the middle third of the clavicle, which tends to increase in size as the child grows [5,9].…”

“…Patients usually present early in childhood with a painless swelling over the middle third of the clavicle, which tends to increase in size as the child grows [5,9]. Differential diagnoses of CPC include obstetric fracture (which tends to rapidly heal with an exuberant callus), cleidocranial dysostosis, neurofibromatosis, and posttraumatic nonunion [5,6,8]. The defining feature of CPC is the existence of a painless lump located above the right clavicle.…”