Surgical instrument for cutting body tissue from a body area having a restricted space

Claim 1

In a surgical instrument for cutting and removing body tissue from a body joint having a restricted space, a cutter comprising a body member and: (a) an elongated external tube carried by the body member and sized for insertion into the restricted space and having an external opening therein extending longitudinally of said tube and having a cutting edge thereon; (b) an internal tube also carried by the body member and positioned within the external tube and having an internal opening therein extending longitudinally of said internal tube and having a cutting edge thereon; (c) the external and internal openings and cutting edges each being relatively movable with respect to the body member and movable concurrently in opposite directions with respect to the longitudinal axes of the tubes to open to receive the body tissue therethrough and to close to cut the body tissue; (d) vacuum means operative to draw a vacuum within the internal tube, for drawing the body tissue in through the external and internal openings; (e) cutter drive means operative to oscillatingly drive the internal tube and the external tube relative to said body member and in opposite rotational directions causing the internal and external cutting edges to cut the body tissue, whereby the vacuum means draws the cut body tissue away from the internal and external openings; and (f) cutter drive control means for independently varying (i) the frequency of the oscillating internal and external cutting edges, and (ii) the dwell time of the internal and external cutting edges when said cutting edges are in the open position while maintaining essentially constant the cutting force exerted by the cutting edges.

Claim 8

A method for surgically cutting and removing body tissue from a body joint having restricted space comprising: (a) placing a cutter, comprising a body member, an external tube carried by the body member and sized for insertion into the restricted space and having an external opening therein having a cutting edge thereon and an internal tube carried by the body member and positioned within the external tube and having an internal opening therein having a cutting edge thereon, the external and internal openings and cutting edges being relatively oscillatingly moveable to open to receive the body tissue, adjacent the body tissue so that the body tissue is immediately adjacent the external opening; (b) drawing the body tissue into the external and internal openings; (c) oscillatingly driving both the internal tube and the external tube relative to said body member and in opposite rotational directions with respect to one another causing the internal and external cutting edges to cut the body tissue; and (d) independently controlling (i) the frequency of the oscillating internal and external cutting edges, and (ii) the dwell time of the internal and external cutting edges when the cutting edges are in the open position while maintaining essentially constant the cutting force exerted by the cutting edges.

Claim 9

A method for surgically cutting and removing body tissue from a body joint having restricted space comprising: (a) placing a cutter, comprising a body member, an external tube carried by the body member and sized for insertion into the restricted space and having an external opening therein having a cutting edge thereon and an internal tube carried by the body member and positioned within the external tube and having an internal opening therein having a cutting edge thereon, the external and internal openings and cutting edges being relatively oscillatingly moveable to open to receive the body tissue, adjacent the body tissue so that the body tissue is immediately adjacent the external opening; (b) drawing the body tissue into the external and internal openings; (c) oscillatingly driving both the internal tube and the external tube relative to said body member and in opposite rotational directions with respect to one another causing the internal and external cutting edges to cut the body tissue; and (d) independently controlling (i) the frequency of the oscillating internal and external cutting edges, and (ii) the dwell time of the internal and external cutting edges when the cutting edges are in the open position while maintaining essentially constant the cutting force exerted by the cutting edges.