DR. DENNIS WILLIAM BURKE, MD
Medical Practice in Boston, MA

4595006, Jun 17, 1986

Aug 16, 1982

6/408468

Dennis W. Burke - South Boston MA
William H. Harris - Belmont MA

A61F 100

128303R

Apparatus and method for polymerizing cement under pressurized conditions and for applying the cement under pressure at the appropriate time to a human bone cavity for implantation of a prosthesis, including a stemmed femoral component and an acetabular component. This apparatus alters the physical conditions under which bone cement cures, causing a decrease in cement porosity and thus increasing the resultant cement strength. The apparatus includes a pneumatically actuated gun having a piston for applying pressure to the cement, and applying cement to the bone, a pressurizable housing securable to the gun for containing the cement, and a nozzle having a valve which allows the cement to remain pressurized until application thereof through the nozzle. In one embodiment, one component of a two component polymerizable cement is provided in a sealed bladder secured to the nozzle while the other component is injected into the bladder and mixed with the first component when the cement is ready for use. A vent may be provided in the piston of the pneumatic gun to allow air to escape through the piston to prevent the injection of air into the cement.

4686971, Aug 18, 1987

Nov 19, 1984

6/673131

William H. Harris - Belmont MA
Dennis W. Burke - South Boston MA

A61F 504

128 92VT

A method and apparatus for extracting a prosthesis, particularly a femoral component of a hip prosthesis, which is embedded in a skeletal bone. The apparatus of this invention includes a hollow housing having a lower bearing surface which bears against the proximal end of the bone surrounding the prosthesis to be extracted, a threaded shaft having one end extending into the housing, means mounted externally of the housing which can be rotated to axially advance the shaft and means disposed on the one end of the shaft disposed within the housing for grasping the prosthesis for extraction thereof. A bearing plate may be provided between the proximal end of the skeletal bone and the bearing surface of the housing to evenly distribute the reaction forces applied by the housing over the exposed surface of the proximal end of the bone, and for a cemented prosthesis, over the exposed bone and cement surfaces. This bearing plate may be provided with any desired angle of slope with respect to the proximal end of the bone. Rotation of the threaded shaft causes a controlled, continuous extraction force to be applied to the component to smoothly and slowly break the bonds between the component and the bone or between the component and cement.