| 摘要 |
A surgical cutting instrument for cutting joint tissue includes an outer tubular member, or cannula, sized for percutaneous insertion into an anatomical space, such as s joint space in the spine. The outer tubular member has a cutting opening at its blunt-tipped distal end. The proximal end is supported by a handpiece. A cutting member is slidably disposed within the outer tubular member and includes a tubular cutting head portion defining an end opening and a cutting edge at the end opening. In the specific embodiment, the cutting member is a tubular tubular member having a cutting head portion at its distal end and a body portion extending therefrom to the handpiece. A hinge is integrally formed in the tubular cannula to connect the cutting head portion with said body portion, to permit pivoting of the cutting head portion relative to the body portion. As the cutting member is reciprocated within the outer cannula, the cutting edge contacts tissue drawn into the cutting opening. Resistance from the tissue causes the cutting head to pivot about the hinge to form an essentially zero clearance between the cutting head and the cutting opening in the outer cannula. |
