Apparatus and method for removal of cement from bone cavities

A method of unidirectionally removing cement from bone cavities, comprising:

• applying an end of an elongated hollow tool, capable of mechanical vibration, to the bone cement;
• melting an area of cement by vibration of the hollow tool;
• and
• aspirating the melted cement by suction applied through said hollow tool,
• wherein the melted cement is unidirectionally removed through said hollow tool.

A method of unidirectionally removing cement from a bone or bone cavity, which comprises:

• placing a surgical apparatus, including a handpiece, a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, an elongated hollow tool operatively associated with said vibration source and attached to said handpiece at a point where essentially no vibration occurs, means for aspiration of the cement, and means for cooling and damping said hollow tool, in contact with the cement at an end of the elongated hollow tool;
• melting the cement by applying energy to said vibration source and thereby transferring mechanical vibration to the cement through the elongated hollow tool to melt said cement without apply traumatic force to the bone;
• aspirating the melted cement by applying suction to remove said cement unidirectionally through said elongated hollow tool;
• and
• selectively cooling and damping lateral vibrations in said hollow tool as required to aid in aspirating by applying a cooling fluid to said elongated hollow tool.

A surgical apparatus for removing cement from bone or bone cavities comprising:

• an elongated hollow tool for applying mechanical vibrations to cement present on a bone or bone cavity of a subject to melt the cement by vibration;
• means for removing the melted cement from the bone or bone cavity unidirectionally through the elongated tool by suction or aspiration;
• a handpiece having first and second ends with a first opening defined by the first end and said tool extending from said first opening;
• a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, said vibration source operatively associated with the elongated hollow tool to vibrate said tool with said tool being attached to the handpiece at a point where no vibration occurs;
• and
• means for rotation of said tool operatively associated with said vibration source wherein said means for rotation enables said tool to rotate about its longitudinal axis through at least one revolution while vibrating to apply shearing forces to the cement;
• wherein no traumatic force is applied to the bone by the vibration and rotation of the tool.

A surgical apparatus for removing cement from bone or bone cavities, comprising:

• an elongated hollow tool for applying mechanical vibrations to cement present on a bone or bone cavity of a subject to melt the cement by vibration;
• means for removing the melted cement from the bone or bone cavity through the elongated tool by suction or aspiration;
• a handpiece having first and second ends with a first opening defined by the first end and said tool extending from said first opening;
• a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, said vibration source operatively associated with the elongated hollow tool to vibrate said tool with said tool being attached to the handpiece at a point where no vibration occurs;
• and
• means for rotation of said tool operatively associated with said vibration source wherein said means for rotation enables said tool to rotate about its longitudinal axis through at least one revolution while vibrating to apply shearing forces to the cement;
• wherein said vibration source includes:
• a tubular piezoelectric crystal having means for electrical contact;
• a union member for connecting said crystal to said elongated hollow tool and having a central passage therethrough, communicating with the elongated hollow tool;
• and
• a hollow stem disposed inside said crystal extending opposing from said elongated hollow tool;
• wherein the stem has a length which is not resonant at the operating frequency of the crystal, and the elongated hollow tool means has a length of .GAMMA./4+n.GAMMA./2 where n is 0 or a positive integer and .GAMMA.=f/c where f is the frequency of operation and c is the velocity of the extensional waves in said elongated hollow tool.

A surgical apparatus for removing cement from bone or bone cavities comprising:

• an elongated hollow tool for applying mechanical vibrations to cement present on a bone or bone cavity of a subject to melt the cement by vibration without applying traumatic force to the bone;
• means for removing the melted cement from the bone or bone cavity unidirectionally through the elongated tool by suction or aspiration;
• a handpiece having first and second ends with a first opening defined by the first end and said tool extending from said first opening;
• a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, said vibration source operatively associated with the elongated hollow tool to vibrate said tool with said tool being attached to the handpiece at a point where no vibration occurs;
• and
• means for cooling and damping lateral vibration at the end of said hollow tool to assist in removal of the melted cement wherein said cooling and damping means is oriented and positioned concentrically about the hollow tool.

A surgical apparatus for removing cement from bone or bone cavities, comprising:

• an elongated hollow tool for applying mechanical vibrations to cement present on a bone or bone cavity of a subject to melt the cement by vibration;
• means for removing the melted cement from the bone or bone cavity through the elongated tool by suction or aspiration;
• a handpiece having first and second ends with a first opening defined by the first end and said tool extending from said first opening;
• a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, said vibration source operatively associated with the elongated hollow tool to vibrate said tool with said tool being attached to the handpiece at a point where no vibration occurs;
• and
• means for cooling and damping lateral vibration at the end of said hollow tool to assist in removal of the melted cement;
• wherein said cooling and damping means is oriented and positioned concentrically about the hollow tool;
• wherein said vibration source includes:
• a tubular piezoelectric crystal having means for electrical contact;
• a union member for connecting said crystal to said elongated hollow tool and having a central passage therethrough, communicating with the elongated hollow tool;
• and
• a hollow stem disposed inside said crystal extending opposing from said elongated hollow tool;
• and
• wherein said cooling and damping means comprises:
• a hollow sleeve having first and second ends surrounding the elongated hollow tool defining an interspace between said tool and said sleeve, said sleeve first end communicating with the first opening in the handpiece, and said hollow tool extending beyond said sleeve second end, wherein a portion of the hollow tool at the end contacting the cement is cut away to define a trough shape at the end, with said cut away beginning inside the second end of the sleeve;
• and
• a hollow tube disposed inside said hollow stem defining a second interspace between said tube and said stem, said tube communicating with said central passage for the passage of aspirated material therethrough, and said second interspace communicating with said first interspace through cooling ports defined by the union member for the passage of cooling and damping fluid therethrough;
• wherein the stem has length which is not resonant at the operating frequency of the crystal, and the elongated hollow tool means has a length or .GAMMA./4+n.GAMMA./2 wherein n is 0 or a positive integer and .GAMMA.=f/c where f is the frequency of operation and c is the velocity of extensional waves in said elongated hollow tool.

A surgical apparatus for removing cement from bone or bone cavities comprising:

• a handpiece;
• a vibration source within the handpiece for generating mechanical vibrations in response to electrical current applied thereto, said vibration source including a tubular piezoelectric crystal, a union member having a central passage therethrough, and a hollow stem disposed inside said crystal;
• an elongated hollow tool connected to the vibration source at the union member and vibrated thereby, said tool attached to said handpiece at a point where essentially no vibration occurs, said hollow tool including an inner tubular member communicating with the central passage of the union member at one end and extending beyond an outer tubular at the opposite end for apply vibration to bone cement without applying traumatic force to the bone, said outer tubular member defining an interspace between said tubular members, and said interspace communicating with cooling ports defined by the union member;
• and
• means for aspiration of the cement, cooling the hollow tool and damping lateral vibrations in the hollow tool, said means including a hollow tube disposed inside said hollow stem defining a second interspace between said tube and said stem, said tube communicating with said central passage for the unidirectional passage of aspirated cement material therethrough, and said second interspace communicating with said first interspace through said cooling ports for the passage of cooling and damping fluid therethrough, and wherein a portion of the inner tubular member is cut away to form a trough the end extending beyond the outer tubular member, said trough extending from the end of the inner tubular member to inside the outer tubular member.