Apparatus and method for injecting bone cement

Claim 1

Apparatus for sealing the opening of a bone cavity during injection of penetrating bone cement into the bone cavity under sufficient pressure to cause the cement to penetrate between the trabeculae of the bone prior to placement of a prosthetic device into the bone cavity, said apparatus comprising; expansible pressure sealing means configured to be frictionally and removably received partially within a bone cavity opening in a relaxed condition and having a central aperture extending therethrough, and expander means frictionally received within the central aperture of said sealing means and configured to expand said sealing means radially outward to engage and form a seal in the bone cavity opening in the expanded condition, said expander means having a passageway in communication with the bone cavity to receive and sealingly engage the tubular nozzle of a bone cement injecting means and conduct cement extruded therefrom into the bone cavity, said expander means and said pressure sealing means in the expanded condition providing a pressure seal between the bone cavity opening and the injecting means whereby the penetrating bone cement will be injected into the bone cavity under substantial pressure and will penetrate between the trabeculae of the bone to thereby provide a bone/cement interface to securely hold said prosthetic device in place.

Claim 10

A method of sealing the opening of a femur bone cavity during injection of penetrating bone cement into the bone cavity under sufficient pressure to cause the cement to penetrate between the trabeculae of the bone prior to placement of a prosthetic device into the bone cavity, said method comprising the steps of; removing the head of the femur to leave an irregular shaped, generally oval opening at the top end of the bone, reaming the interior of the femoral canal to create an elongate cavity, installing a plug at the lower end of the cavity in a manner to prevent bone cement from escaping thereby, filling the plugged femur cavity with penetrating bone cement from the plug to the lip of the opening of the femur, installing an expansible sealing plug having a longitudinal aperture extending therethrough partially into the opening such the one portion is inside the cavity and another portion is outside the cavity, installing a tapered expander member having a tapered bore extending therethrough in communication with the cavity into the aperture of the sealing plug such that the plug is expanded radially outward to conform to the shape of the opening and form a sealing engagement therewith and the portion of the plug inside the cavity is expanded to seal against the inside walls of the cavity adjacent the opening and portion outside the cavity engaging the exterior plateau surface surrounding the opening in a sealing relation, inserting the tubular nozzle of a cement cartridge carried in a cement injection gun into the tapered bore with sufficient force to become frictionally engaged on the bore side wall, creating pressure within the cement mass by pressing the cement injection gun against the assembled sealing plug and expander member and squeezing the handle and trigger of the gun together thereby causing the injection gun to develop high pressure within the cement mass for a predetermined time period, said expander member and said sealing plug in the expanded condition providing a pressure seal between the bone cavity opening and the injection gun whereby the penetrating bone cement will be injected into the bone cavity under substantial pressure and will penetrate between the trabeculae of the bone, and following the predetermined time period of cement pressurization, inserting the stem of a prosthesis into the cement and allowing the cement to harden to provide a bone/cement interface to securely hold the prosthetic device in place.

Claim 11

A method of sealing the opening of a femur bone cavity during injection of penetrating bone cement into the bone cavity under sufficient pressure to cause the cement to penetrate between the trabeculae of the bone prior to placement of a prosthetic device into the bone cavity, said method comprising the steps of; removing the head of the femur to leave an irregular shaped, generally oval opening at the top end of the bone, reaming the interior of the femoral canal to create an elongate cavity, installing a plug at the lower end of the cavity in a manner to prevent bone cement from escaping thereby, filling the plugged femur cavity with penetrating bone cement from the plug to the lip of the opening of the femur, installing an expansible sealing plug having a longitudinal aperture extending therethrough partially into the opening such the one portion is inside the cavity and another portion is outside the cavity, installing a tapered expander member having a tapered bore extending therethrough in communication with the cavity into the aperture of the sealing plug such that the plug is expanded radially outward to conform to the shape of the opening and form a sealing engagement therewith and the portion of the plug inside the cavity is expanded to seal against the inside walls of the cavity adjacent the opening and portion outside the cavity engaging the exterior plateau surface surrounding the opening in a sealing relation, inserting the tubular nozzle of a cement cartridge carried in a cement injection gun into the tapered bore with sufficient force to become frictionally engaged on the bore side wall, creating pressure within the cement mass by pressing the cement injection gun against the assembled sealing plug and expander member and squeezing the handle and trigger of the gun together thereby causing the injection gun to develop high pressure within the cement mass for a predetermined time period, said expander member and said sealing plug in the expanded condition providing a pressure seal between the bone cavity opening and the injection gun whereby the penetrating bone cement will be injected into the bone cavity under substantial pressure and will penetrate between the trabeculae of the bone, and following the predetermined time period of cement pressurization, inserting the stem of a prosthesis into the cement and allowing the cement to harden to provide a bone/cement interface to securely hold the prosthetic device in place.