Devices for percutaneous surgery

An apparatus for use in percutaneous surgery, comprising: an elongated cannula (20) sized for percutaneous introduction into a patient, said cannula defining a working channel (25) and having a longitudinal axis extending between a distal end of work (21) and an opposite proximal end (22), said cannula further defining a length between said distal end and said proximal end and an outer surface (23) thereabout; one clamping assembly (350, 400) engageable to said outer surface of said cannula at various positions along said length of said cannula; characterized in that said clamp assembly includes a portion (390) receiving a display element formed with said clamp assembly; and a display element (310) is removably coupled to said clamp assembly (350, 400) through a receptacle (396) defined by one element, the display element (310) or Lapart (390) receiving the display element, which receptacle receives a dovetail (330) defined in the other of said elements, the display element (310) or the (390) receiving the display element.