A pediatric medial epicondyle fracture study using fresh frozen adult cadavers comparing fracture displacement and loss of terminal elbow extension.

Medial epicondyle fractures are the 3rd most common pediatric elbow fractures. Regardless of treatment method, some degree of elbow motion loss has been reported. The purpose of our study was to determine the relationship between the amount of anterior fracture displacement and loss of elbow passive extension in an adult cadaveric medial epicondyle fracture model. Fifteen fresh frozen adult cadavers were procured to create fracture models at scenarios of 2, 5, 10 mm, and maximum displacement. Terminal elbow extension was recorded for each cadaveric model at each fracture scenario. A linear mixed model regression analysis was used to test the association between fracture displacement and loss of terminal elbow passive extension. At 2 mm of displacement, the average loss of terminal extension was 3.89°; at 5 mm, it was 7°; at 10 mm, it was 10.7°; at maximum displacement (~15 mm), it was 17°. A statistically significant positive linear association between fracture displacement and loss of terminal elbow extension was observed (5 mm of displacement = loss of ~4.7°). In our fracture model, when the medial epicondyle displaced anteriorly, we noticed a change in the tension of the medial collateral ligaments which lead to a decrease in terminal elbow extension. However, this only contributed partially to the loss of motion observed clinically in the literature. Even though our findings did not support the recommendation of surgical intervention to prevent loss of elbow motion in medial epicondyle fractures, we still encourage physicians to consider the consequence of displacement and its potential influence of elbow range of motion.