[Linburg-Comstock syndrome. Epidemiologic and anatomic study, clinical applications].

The Linburg-Comstock (LC) syndrome is distinguished by the inability to actively flex the interphalangeal (IP) joint of the thumb without simultaneously flexing the distal IP joint of the index finger. Any resistance to this 'parasitic' reaction causes pain on the palmar side of the wrist or in the distal part of the forearm; this is due to an anomalous tendinous connection between the flexor pollicus longus (FPL) and the flexor digitorum profundus (FDP). An epidemiological study was carried out on 264 individuals (a total of 528 hands were examined), and the LC syndrome was found in 98 subjects (37%); women were more frequently affected than men, and bilaterally rather than unilaterally. In addition, we dissected 26 fresh cadaver upper limbs, and in seven cases found an anomalous connection between FPL and FDP. We also examined the case of a young violinist with bilateral LC syndrome, who complained of pain in the distal part of the left forearm after prolonged musical exercises. Surgical investigation determined a complete fusion between FPL and FDP of the index with a common tendon. Treatment consisted of splitting this common tendon to form two separate tendons, thereby permitting a certain degree of independence between the thumb and index finger, and which considerably improved the violinist's musical performance. A review of the literature showed that there was a large quantity of anatomical descriptions available on these types of connection. Certain publications also provide an extremely precise report on the anthropological significance of these anomalies.