Explant culture, immunofluorescence and electron-microscopic study of flexor retinaculum in carpal tunnel syndrome.

Although flexor-retinaculum (FR) release provides dramatic relief from carpal tunnel syndrome (CTS), the role of this ligament in CTS is not well understood. We have adopted a unique approach to study the cellular pathogenesis of CTS by establishing a method for the culture of cells of FR from subjects with and without CTS. The cultured cells were characterized by light, immunofluorescence, electron microscopy, Western blot analysis, and growth studies. Two main differences between the CTS and control cells included a faster growth rate and an altered fine morphology that reveals the contractile nature of the CTS cells. It is possible that the presence of these contractile cells in FR is responsible for increasing the contractility of the FR, leading to a decrease in the volume of the carpal tunnel, thus exerting pressure on the median nerve and triggering CTS.