Bilateral Pseudoarthrosis of the Clavicles without Cbfa1/ Runx2 Gene Mutation: A Case Report

Case Report

Austin J Orthopade & Rheumatol. 2017; 4(2): 1056.

Bilateral Pseudoarthrosis of the Clavicles without Cbfa1/ Runx2 Gene Mutation: A Case Report

Thomas D¹, Sandow MJ², Evdokiou A³ and Findlay DM³*

¹Department of Medicine, University of Melbourne at St Vincent’s Hospital, Fitzroy, Australia

²Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, Australia

³Discipline of Orthopaedics and Trauma, University of Adelaide, Adelaide, Australia

*Corresponding author: David M Findlay, Discipline of Orthopaedics and Trauma, Adelaide Health and Medical Sciences Building, University of Adelaide, North Terrace, Adelaide, South Australia 5000, Australia

Received: August 18, 2017; Accepted: September 18, 2017; Published: September 25, 2017


We have identified an individual with bilateral pseudoarthrosis of the clavicle, presumed to be congenital, with no family history of the condition, no evidence of postnatal trauma to the clavicles and no other overt skeletal abnormalities. The genetic basis of pseudoarthrosis of the clavicle has not been identified, although Cleidocranial Dysplasia (CCD), a congenital condition characterized by skeletal anomalies that include hypoplastic and/or aplastic clavicles, has been mapped to chromosome 6p21 and shown to result from mutations in the Cbfa1/ runx2 gene. We therefore investigated the possible involvement of Cbfa1/runx2 mutation by sequencing all 7 exons of the gene. No changes were found in the coding sequence of Cbfa1/runx2 in this case of pseudoarthrosis of the clavicles and the genetic basis for congenital pseudoarthrosis of the clavicles remains to be determined.

Keywords: Clavicle; Bilateral Pseudoarthrosis; Cbfa1 gene

Case Presentation

We report a case of bilateral pseudoarthrosis of the clavicles in a 21 year-old white male, who was otherwise skeletally normal and showed no adverse effects from his condition. His parents and a younger female sibling were unaffected. Since visualisation of the clavicle is suboptimal using standard radiographs, a high resolution shoulder-to-neck CT, with 0.5mm slice thickness, was performed. 3D reconstruction of the CT was performed using True Life Anatomy software (TLA Generator, Rubamas, Adelaide; to create a surface rendered model of the upper thorax showing skin, clavicles and lungs as separate objects. Figure 1 demonstrates clearly the complete discontinuity at the midshaft of both clavicles. The overall alignment was reasonable, although there was inferior displacement of the lateral fragment with respect to the medial shaft. The appearance was symmetrical, and the clavicles were well aligned with the thorax. There was no significant tendency for medialisation of the shoulder girdle. There was no particular overriding of the clavicles, which was explained after further manipulation of the 3D images, using different image thresholds, revealed a cartilage anlage joining the ends of the clavicles together (not shown). This would explain the relatively stable position of the shoulder girdle, despite the apparent discontinuity, as distinct from the normal overriding following acute clavicular fracture.

Citation: Thomas D, Sandow MJ, Evdokiou A and Findlay DM. Bilateral Pseudoarthrosis of the Clavicles without Cbfa1/Runx2 Gene Mutation: A Case Report. Austin J Orthopade & Rheumatol. 2017; 4(3): 1056. ISSN:2472-369X