Analise dos mecanorreceptores e terminações nervosas livres do ligamento transverso do carpo

Abstract

The treatment of carpal tunnel syndrome by sectioning the transverse carpal ligament (LTC) is not exempt from complications. Some nerve branches may be damaged by the incision. The aim of the present study is to identify and map the LTC nerve endings, serving as a guide for sectioning this structure in a zone with less nerve ending density. Ten LTCs were obtained from five fresh cadavers. The LTCs were measured, divided into 3 equal bands (radial, central and ulnar) and submitted to cryostat sectioning. The sections were subjected to immunofluorescence with the PGP 9.5 and confocal microscopy analysis. Width was 28.15 ± 1.18mm. The central band was the shortest, measuring 15.38 ± 0.58mm. The radial and ulnar bands were 17.61 ± 0.65 mm and 16.16 ± 0.63 mm long, respectively. All the specimens contained type I and type IV mechanoreceptors. Neural elements occupied 0.695 ± 0.056% of the ligament area. The density of the neural elements was greater in the radial, followed by the ulnar and central bands, with 0.730 ± 0.083%, 0.686 ± 0.009% and 0.669 ± 0.031%, respectively. The present findings suggest that the region with the least potential for neural element injury during LTC release is the central third near the transition with the ulnar third. When performed distally to proximally with a slight inclination from the radial to the ulnar, this release compromises the lowest nerve element density. Topographically, the proximal limit of the release is the distal wrist crease, while the distal limit is the intersection of Kaplan’s cardinal line and the axis of the third webspace.