Purpose The aim of the present case is to describe an interesting variation of the additional head of the rectus femoris. Methods A male body donor, 81 years old at death, was subjected to routine anatomical dissection for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland. Results We have found an example of an accessory head of the quadriceps femoris, a double-headed rectus femoris in which the proximal attachment is connected to the rectus femoris muscle originating from the anterior inferior iliac spine. The muscle belly of this additional structure is separate but fused distally with the vastus lateralis muscle. It then passes into the patellar ligament inserted into the tibial tuberosity. Conclusions Knowledge of the possible occurrence of an additional head is nevertheless important for clinicians, especially for orthopedists performing reconstructive surgeries. It could also be significant for physiotherapists arranging rehabilitation plans after such surgeries because it could potentially help to achieve faster recovery.
