A. Yu2, C. F. Janney1,3, D. C. Jupiter1,4, V. K. Panchbhavi1 1University of Texas Medical Branch,Department Of Orthopaedic Surgery And Rehabilitation,Galveston, TX, USA 2University of Texas Medical Branch,School Of Medicine,Galveston, TEXAS, USA 3Navy Medical Center San Diego,United States Navy,San Diego, CALIFORNIA, USA 4University of Texas Medical Branch,Preventive Medicine And Population Health,Galveston, TX, USA
Introduction: Humerus fractures are a common fracture in the United States (US). The purpose of this study was (1) to compare estimated overall and age stratified incidence rates of proximal and distal arm fractures presenting to US emergency departments (EDs) using the National Electronic Injury Surveillance System (NEISS) between 2005-2009 and 2015-2019; (2) to compare humerus fracture locations stratified by age or sports-related trauma reported in the NEISS between these two periods.
Methods: The NEISS was used to obtain US estimates of proximal and distal arm fractures for the years 2005-2009 and 2015-2019. ED visits were identified using injury code (57: Fracture) and body codes (80: Upper Arm, 33: Lower Arm). Fracture rates were normalized using US Census Estimates and stratified by age for their respective periods. Case summaries were filtered for humerus fractures and further filtered for anatomic and non-specific (proximal, middle, distal third) fractures. Reported anatomic fractures were stratified by sports trauma and divided into non-impact and impact related trauma. Relative humerus fractures, inclusive of anatomic and non-specific locations, were stratified by age and compared between the two periods. Chi-squared test was used to compare fracture rates between the two periods. Statistical significance was set at P<0.05.
Results: During the two periods studied, participating NEISS EDs coded 47,066 proximal and distal arm fracture cases from 2005-2009 (1,450,335 injuries nationally; 95% CI 1,180,435 – 1,720,234), and 48,565 arm fractures from 2015-2019 (1,499,014 injuries nationally; 95% CI 1,147,809 – 1,850,219). There was a significant decrease (p<.0001) in proximal and distal arm fracture rates from 2005-2009 to 2015-2019; further, there was a significant difference in fracture rates between the two periods with respect to age group distributions (P < .0001). Proximal and middle third humerus fractures were bimodal in nature, with peak cases occurring between 10-14 years and 55 years and older (proximal third) or 60 years and older (middle third) for both periods. Distal third humerus fractures were right skewed, with peak cases for both periods occurring at 5-9 years. Bicycling, football, and gymnastics accounted for the top three sports related fractures, respectively, for both periods. Impact related sports trauma accounted for most fractures during both periods. Interestingly, non-impact related sports trauma consisted entirely of thrower’s fractures resulting in primarily midshaft fractures.
Conclusion: Proximal and distal arm fracture rates decreased and distributions differed by age between the two periods in the US. Proximal, middle, and distal third humerus fracture distributions differ by age but were similar between both periods. One major non-impact sports related trauma was high external rotational torque from pitching, suggesting possible precautions that may protect against thrower's fractures.