14 year old girl complaining of a 2-week history of non-specific shoulder pain. Onset of symptoms occurred after an intensive softball throwing practice. Symptoms were aggravated by any shoulder movements away from the body and resulted in a non-specific shoulder ache.
Normal sonographic appearance of the rotator cuff tendons, AC and GH joints.
Normal rotator cuff anatomy
Upon extending the scan, a cortical breach and associated periosteal reaction was observed on the distal 3rd of the 1st rib. Note the intimate relationship between the 1st rib and the overlying brachial plexus and brachial artery.
Cortical irregularity of the 1st rib
Rib in long axis. Note the overlying brachial plexus.
X-ray confirming the rib stress fracture
An X-ray was performed to confirm the diagnosis and exclude further bony pathology. Note the cortical breach on the medial aspect of the 1st rib
Stress fractures commonly occur due to a rapid increased in load, without the ability of the bone to adequately recover and remodel to the load demands. Stress fractures of the 1st rib commonly occur due to an increase in torsional stress placed on the bone due to the serratus anterior and scalene muscular forces involved in upper limb throwing activities.