Postnatal Growth of the Clavicle: Birth to 18 Years of Age

Author(s): McGraw MA, Mehlman CT, Lindsell CJ and Kirby CL

Source: J Pediatr Ortho 29(8):937-943, 2009.

Summary:

The clavicle has the honor of being the first bone to start the ossification process and the last to finish.  The clavicle is also a commonly fractured bone.  This success of non-operative treatment has been attributed to the remarkable remodeling potential in growing children.  However, the postnatal growth of the clavicle not well defined.  The authors attempt to define this growth pattern of the clavicle from birth to 18 years of age.

A retrospective review of 961 individuals between birth and 18 years of age was performed.   Inadequate x-rays were excluded.  The authors divided the cohort into 19 groups based upon chronological age.  The clavicle lengths were measured in millimeters using appropriate software.  Standard statistical analysis was also performed.

At 18 years of age, the clavicle length for females was approximately 150 millimeters and approximately 160 millimeters for males.  A steady growth rate was noted for both genders from birth to 12 years of age, at 8.4 millimeters per year.  Above the age of 12 years, boys grew at twice the rate compared to girls.   The data indicates that females achieve 80% of the clavicle length by 9 years of age, and boys by 12 years of age. 

The authors utilize their data to hypothesize that remodeling of the clavicle after fracture occurs more readily in females less than 9 years of age, and boys less than 12 years of age.  This information may effect the management of displaced clavicle fractures in older aged females or males.  This supports the ongoing trend for operative fixation of older age pediatric clavicle fractures.  However, as stated in previous review on operative fixation of clavicle fractures, the precise clinical inference remains unclear.  There needs to be a pediatric cohort studied with the same riggers as the adult population to make any conclusions regarding operative indications for pediatric clavicle fractures.