A Complex Cross Link between the Tendons of Flexor Hallucis Longus and Flexor Digitorum Longus

Abstract

Anatomical variations involving the flexor digitorum longus (FDL) and flexor hallucis longus (FHL) tendons are clinically important because of their significant role in reconstructive surgeries of tibialis posterior tendon insufficiencies and Achilles tendinopathies. Harvesting of grafts from these complex variations of FDL and FHL are surgically challenging. In the present case, we report a complex structural cross link between the FDL and FHL associated with morphological variations of the first lumbrical and flexor digitorum accessorius (FDA) attachments. A connecting slip from FHL was found to be inserted into the FDL tendon of the second toe. The FDA was inserted into the fibular side of the connecting slip of the FHL as well as into the FDL tendons of the third and fourth toes. The first lumbrical took origin from the tibial side of FHL connecting slip and from the tibial side of FDL tendon for second toe.