Letter Regarding “Linburg-Comstock Anomaly”

Abstract

We read with interest this In Brief article in the August 2014 issue of the Journal.1Gancarczyk S.M. Strauch R.J. Linburg-Comstock anomaly.J Hand Surg Am. 2014; 39: 1620-1622Google Scholar In our experience, the finding of a functional connection between the index finger flexor digitorum profundus and the flexor pollicis longus is common, but a pathological connection causing pain or neurological deficit is rare. The anomalous connection causes chronic thickened tenosynovial encasement of the flexor tendons. Neurological manifestations can occur due to increased carpal tunnel contents either from the synovial membranes or intertendinous connections. This results in classic nocturnal symptoms, but also in symptoms after exercise probably due to increased blood flow and tissue edema. Simple median nerve decompression may result in resolution of the neurological symptoms and pain. In our experience, some patients may present with sudden severe neurological symptoms during activities that result from differential gliding of the index finger flexor digitorum profundus and the flexor pollicis longus tendons. These patients may have no or limited relief from carpal tunnel decompression. This represents traction neuropathy due to encasement of the median nerve and tether to the index finger flexor digitorum profundus and flexor pollicis longus in the distal forearm. Careful examination will identify these patients' pathology and a diagnostic local anaesthetic injection2Puroshothaman B. Power D. A simple diagnostic test for symptomatic Linburg-Comstock anomaly.Internet J Hand Surg. 2008; 2Google Scholar at this site may help to establish the diagnosis of traction neuropathy. We have successfully treated these patients with combined tenolysis and external neurolysis of the median nerve at this site. Linburg-Comstock AnomalyJournal of Hand SurgeryVol. 39Issue 8PreviewLinburg-Comstock anomaly consists of tendinous interconnections between the flexor pollicis longus (FPL) muscle belly or tendon and the flexor digitorum profundus (FDP), usually of the index finger.1 Tendon slips connecting the FPL and the FDP were recognized by anatomists as early as the 1800s.1 In 1979, Linburg and Comstock1 found the variant unilaterally in 31% of their study population and bilaterally in 16%. Full-Text PDF