Abstract:

During routine dissection of 11 cadavers that originated with the Body Donor Program at PCOM Georgia, a 69-year-old male with bilateral extensor anomalies in the dorsal forearm compartment was encountered. The distinct muscle belly, identified as the extensor medii proprius, originated from the distal ulna and inserted into the dorsal aponeurosis of the third digit. Manual traction of the right tendon resulted in extension of the third digit, suggesting functional significance of the anomalous muscle. This case study analyzes the extensor medii proprius found during dissection, its prevalence, embryologic origins, and clinical significance. The presence of the extensor medii proprius muscle and tendon must be considered when assessing pain in the dorsum of the hand and when preparing for surgical repair or tendon transfer.