Common Palmar Digital Communicating Branch. Anatomical Analysis and Surgical Implications

Purpose: The common palmar digital communicating branch (CB) establishes the connection among the common palmar digital branches (CPDB) in the human hand. Described with a prevalence over 60%, this CB is closely related to the flexor retinaculum (FR), which makes it vulnerable in carpal tunnel release surgery.
Methods: Our aim was to establish the relationship between the prevalence, biometry and topography of the CB with the hand laterality and sex. A descriptive-correlational, quantita- tive, nonexperimental and transectional study was conducted. Thirty adult human hands belonging to the cadaver donation program of Pontificia Universidad Católica de Chile were dis- sected. The samples were fixed in formalin and stored at 4°C.
Results: The CB appeared in 21 cases (70%), being bilateral in 11 (52%). In 18 cases (86%) the CB emerged from the IV CPDB and was added to the III CPDB. The average CB length was 17 mm. According to the Ferrari and Gilbert classification, Group III appeared in 11 cases (52%) and Group I in 9 (43%). A positive and moderate correlation was established (p=0.014; r=0.527) between hand length and the distance between the distal margin of the FR and the midpoint of the CB length.
Conclusion: The prevalence reported supports the CB be- ing part of the normal anatomy. The classification of the CB differs from reports in other geographic areas. Given the prev- alence of the CB and its close relation with the FR, this forma- tion must be considered in hand surgery treatment planning.