Shoulder dystocia complicates vaginal delivery due to difficulty in delivering the fetal shoulder after the head has been delivered. This occurs because the fetal anterior shoulders become impacted behind the symphysis while the posterior shoulders may be obstructed at the sacral promontory. Anterior obstruction occurs more common than the posterior obstruction. This traumatic event can result to nerve / brachial plexus injuries. Clavicle fractures in this cases may be the result or even intentional, latter of which is aimed at shortening the biacromial diameter. Multiple maneuvers have been designed to cope with this condition during delivery.
Clavicular fractures may be complete or incomplete and may occur in one of both sides. Incidence increases with increasing fetal weight from those with fetal weight of 2500 grams to 4000 grams and higher; The greatest incidence, is seen in those with fetal weights of 4000 grams or higher. It may be undetected until a lump at the region of the collar bone or lack of movement of the ipsilateral upper extremity. Although it occurs more often during vaginal deliveries, cases of clavicular fractures from Caesarean deliveries have been reported.
The plain radiograph remains the mainstay / initial imaging tool to evaluate for clavicular fractures, particularly during the immediate post-delivery period.