The Tendinous Slip of the Flexor Digitorum Longus for the Great Toe: An Anatomic Variation

Lee, Ju Young; Hur, Mi Sun

Abstract

This report describes a variation of the tendinous slip of the flexor digitorum longus (FDL) for the great toe. In addition, compositions of the long flexor tendons for all five toes were examined. The tendons of the FDL in the foot were investigated in 66 specimens of embalmed Korean adult cadavers. The tendons of the flexor hallucis longus (FHL) and the FDL with the lumbrical muscles were cut at the calcaneus and the metatarsophalangeal joints and were removed en bloc specifically to observe the FDL and the FHL tendons of the great toe. The tendinous slip of the FDL for the great toe was found bilaterally in the foot of a 52-year-old male. Its prevalence was two of 66 specimens (3.0%). The tendinous slip of the FDL for the great toe passed forward the great toe, and it constituted the superficial portion of the long flexor tendon for the great toe. The tendon of the FHL passed forward to constitute the deep portion of the long flexor tendon for the great toe. Thus, both the tendinous slip of the FDL and the tendon of the FHL composed the long flexor tendon for the great toe. The tendinous slip of the FDL and the tendon of the FHL for the great toe were similar in thickness; thus, each tendinous slip of the FDL and the tendon of the FHL were approximately one-half of the long flexor tendon for the great toe in thickness. The present study demonstrated an anatomical variation of the interconnection between the FHL and the FDL tendons, which will be useful for various surgeries and biomechanical research.