[The Linburg-Comstock phenomenon: a review].

Simultaneous flexion of thumb and fingers is described as the Linburg-Comstock phenomenon. Congenital and acquired coupling of the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) tendons is the reason for this clinical entity. Additionally, coupling of the FPL and the flexor digitorum superficialis II or III has been described. The coupling can be between the muscles, the tendon sheaths or the tendons themselves. Asymptomatic and symptomatic coupling should be differentiated. In general symptomatic congenital or acquired coupling demands surgical intervention. We report about a 35-year-old patient with a congenital asymptomatic coupling of FPL and FDP-II who suffered a distorsion of the thumb. Afterwards she complained of pain and strength loss. An accessory tendon of 3 mm in diameter and 3.5 cm length between FPL and FDP-II was identified during surgery. The patient recovered completely after resection of this coupling.