Medial injuries of the clavicle: more prevalent than expected? A big data analysis of incidence, age, and gender distribution based on nationwide routine data

PURPOSE: Although shoulder-girdle injuries occur frequently, injuries of the medial part remain widely unexplored. This study overviews these rare injuries with a focus on incidence, age, and sex distribution in Germany. METHODS: The data are based on diagnoses according to ICD-10 in all German hospitals provided by the German Federal Statistical Office. ICD-10 codes S42.01 (medial clavicle fracture, MCF) and S43.2 (sternoclavicular joint dislocation, SCJD) were evaluated in detail between 2012 and 2014. RESULTS: We identified 14,264 cases with medial clavicle injuries (MCIs). MCFs occurred more often (11.6% of all clavicle-related shoulder-girdle injuries vs. 0.6% for SCJD). Mean ages of MCI were significantly different between males (43.7 years) and females (57.1 years) (p < 0.01). Age demonstrated a bimodal distribution with peaks at 20 and 50 years, which were predominantly associated with males. Females showed more injuries at age beyond 70 years. This applies to both SCJD and MCF. The incidence rate of these shoulder-girdle injuries was 47.0 per 100,000 person-years, for MCIs overall 5.9 (4.1 for men, 1.8 for women). This indicates disparity with a significant predominance of male patients over females as for all shoulder-girdle injuries (p < 0.01). Among children (< 16 years old), the incidence rate showed no significant difference in gender ratio. CONCLUSION: MCIs appear more frequently than estimated so far and are distinguished from other clavicle fractures in that they occur more at higher age and peaking around 50 years. Further work on possible prevention strategies should focus on the most frequently affected groups of men around 20 and 50 years old.