Risk of Neurovascular Injury with Limited-Open Carpal Tunnel Release: Defining the “Safe-Zone”

Abstract

Limited-open carpal tunnel release was performed in ten cadaver arms using the “Safeguard” system. The “Safeguard” guide was intentionally placed off of the longitudinal middle/ring finger axis, either in 15° of radial deviation or 15° of ulnar deviation. Despite the errant placement, carpal tunnel release was performed without damage to any neurovascular structure. The proximity of neurovascular structures to the middle/ring finger axis was measured in all ten cadaver specimens. From this, a “safe-zone” was defined for endoscopic or limited-open carpal tunnel release. The “safe-zone” expands when surgery is performed from distal to proximal. The area of the “safe-zone” is greatest when a protective guide is placed between the bursal sac of the carpal canal and the flexor retinaculum.