Altered hand proprioception following regional anesthesia as a cause of traumatic jersey finger: Report of two cases.

The sense of body ownership is being increasingly studied by manipulating incoming signals from the periphery with local anesthetics. We sought to understand how altered proprioception induced by anesthesia triggered a traumatic jersey finger, immediately postoperatively, in two patients who underwent surgical carpal tunnel release. Multiple mechanisms contributed to these postoperative injuries associated with a fall. Hand anesthesia deprives the brain of important afferent sensory information and modifies hand size perception in the brain. Moreover, it blocks efferent motor signals that contribute to the perception of hand position with sensory afferent signals. When the patients fell, their movement control was inadequate, generating a strong contraction of the hand extrinsic flexor muscles, against forceful distal phalanx extension. Lastly, both patients had removed their numb operated hand from their arm sling. Disrupted sensory and motor paths modify self-attribution of the hand, and thus halt adequate efferent commands. Protecting the operated hand until full sensory and motor control is regained could have prevented such rare accidents from happening. Level of evidence: V.

The first case of hourglass-like constriction neuropathy of a digital nerve.

Neuropathies of digital nerves are an infrequent phenomenon and their causes are most often mechanical. A rare cause of acute neuropathy is hourglass-like fascicular constriction of a nerve due to torsion. Although several cases of hourglass-like constriction have been described in the literature, none to our knowledge involved digital nerves. In this report, we present the first case of hourglass-like constriction of a digital nerve.

Trans-metacarpophalangeal traction to avoid finger-related complications during wrist arthroscopy: Feasibility study with 20 cadaver wrists.

Some of the iatrogenic complications of wrist arthroscopy are related to the traction applied to the fingers. The aim of this work was to test whether trans-metacarpophalangeal (trans-MCP) traction would provide sufficient distraction of the radiocarpal and midcarpal joint spaces to perform wrist arthroscopy without exerting any mechanical stress on the fingers, from the metacarpophalangeal (MCP) joints to the distal phalanges. Our study included 20 cadaveric wrists mounted on an arthroscopic traction tower maintained by finger traps placed on the 2nd and 4th fingers. For each wrist, three fluoroscopic views were taken: without traction, with finger traction (78.45N), with trans-MCP traction (78.45N). The average height of the midcarpal joint space was 0.8305cm without traction, 1.037cm with finger traction, and 1.1cm with trans-MCP traction. The height of the radiocarpal joint space averaged 0.853cm without traction, 1.167cm with finger traction, and 1.187cm with trans-MCP traction. There were no differences between the heights of joint spaces between digital and trans-MCP traction. Our results show that trans-MCP traction provides distraction of the wrist joint spaces equivalent to that obtained with finger traction. However, we still need to develop a trans-MCP traction device usable in clinical practice.