US Patent 9271750 Expandable cannula and method of use

A cutting device includes an elongated shaft that extends between a proximal end and a distal end. A distal arm extends from the distal end of the elongated shaft. The distal arm includes an inner surface defining a cavity and an outer surface defining a blunt tip. At least one proximal arm extends from the distal end of the elongated shaft at a position proximal to the distal arm. The at least one proximal arm having an inner surface defines a cavity including a cutting portion configured to cut tissue.