Anatomo-histological analysis of the juncturae and their relations to the extensor tendons to the dorsum of the hand

The juncturae tendinum (JT) may coordinate the extension of hand, force redistribution and the stabilization of the metacarpophalangeal joint. The JT were studied for their gross appearance, shape, thickness, location and histological examination with the dorsum of the hand in 54 cadavers. The JT were identified into three groups according to their anatomo-histological features. The type 1 was observed in 57.4% of the cases in the second IMC and in 16.7% of the cases in the third IMC. The type 2 was detected in 3.7% of the cases in the second IMC and in 59.3% of the cases in the third IMC space. The type of 3Y was accounted for 14.8% JT in the third IMC space and 53.7% JT in the fourth space. The type of 3r was found in 5.55% of the cases in the third IMC and in 37% of the cases in the fourth IMC space. In the histologic examination, the fibers of types 1 and 2 JTs were straight. Type 3 JTs were composed of regularly oriented parallel and crosswise bundles of tendineous tissue. This study is important in terms of giving accurate knowledge on the anatomo-histological analysis of the JTs and their relations to the extensor tendons to the dorsum of the hand. An understanding of the structures of the JTs and the interactions between the tendons of the fingers is of utmost importance in hand assessment, during the reconstructive procedures such as considering the tendons to be transferred.