An anatomical study of intertendinous connections between the flexor hallucis longus and flexor digitorum longus tendons in fetal cadavers.

The attachment between the flexor hallucis longus and flexor digitorum longus tendons is referred to as the "Henry's knot" in the literature. This structure is considered a vital anatomical reference point in numerous clinical applications. Accurate knowledge of the morphological features and variations of the Henry's knot is critical, particularly in preventing iatrogenic injuries during surgical procedures. The aim of this study is to examine the anatomical features of Henry's knot in detail, to classify it morphologically, and to contribute to the developmental and clinical anatomy literature by measuring its distances from anatomical reference points.Our study was conducted using anatomical dissection of 58 fetal cadavers (29 female and 29 male) aged between 17 and 40 weeks of gestation. Henry's knot was categorized into 6 types. Type 1 was the most common type found (51.7%, N = 60). The contribution of the flexor hallucis longus to the movement of the lesser fingers was divided into 7 types. Type B was the most common type found (81.9%, N = 95). No statistically significant differences were found in the distances of Henry's knot from various landmarks between sexes and sides. In our study, flexor hallucis longus and flexor digitorum longus tendons in fetal cadavers were examined in detail. We believe that this study will provide valuable information to orthopedists, pediatricians, and surgeons, and will also benefit anatomists by improving their anatomical knowledge.