Abstract: A downhole apparatus adapted to be run on a workstring in a well bore. The apparatus has a body including ports and a valve which is rotatable to open and close the ports to selectively allow fluid flow through the body between regions of a well bore above and below the apparatus. The valve is rotated via a gearbox and motor in the apparatus. A sealing arrangement between the valve and body is also described. A method of running the apparatus in a well bore and monitoring pressure above the apparatus in order to control opening and closing of the valve under predetermined conditions is presented.

Abstract: A milling system is disclosed for creating a cavity in a bone. The cavity has a cross section which has a generally triangular profile having a first side generally parallel with an axis of the bone and a second side forming an acute angle with the first side. The cavity is contiguous with a pre-existing conical cavity in the bone. The system comprises a drive shaft, a frame for carrying a cutter and a cutter for cutting the cavity. The drive shaft has a proximal end configured for coupling to a drive means and a distal end configured to form a portion of a drive joint for coupling the drive shaft to a cutter. The frame includes a shaft and a cutter mount for mounting a cutter at a first angle approximating the acute angle with respect to the shaft. The mount includes a bracket extending laterally from the shaft to a bearing configured to receive a portion of a cutter and maintain the received cutter oriented at the first angle during rotation.

Abstract: A milling system is disclosed for creating a cavity in a bone. The cavity has a cross section which has a generally triangular profile having a first side generally parallel with an axis of the bone and a second side forming an acute angle with the first side. The cavity is contiguous with a pre-existing conical cavity in the bone. The system comprises a drive shaft, a frame for carrying a cutter and a cutter for cutting the cavity. The drive shaft has a proximal end configured for coupling to a drive means and a distal end configured to form a portion of a drive joint for coupling the drive shaft to a cutter. The frame includes a shaft and a cutter mount for mounting a cutter at a first angle approximating the acute angle with respect to the shaft. The mount includes a bracket extending laterally from the shaft to a bearing configured to receive a portion of a cutter and maintain the received cutter oriented at the first angle during rotation.

Abstract: A milling system for creating a cavity in a bone includes a drive shaft, a frame for carrying a cutter and a cutter for cutting the cavity. The drive shaft has a proximal end and a distal end forming a portion of a drive joint for coupling the drive shaft to a cutter. The frame includes a frame shaft and a cutter mount, mounting a cutter at a first angle. The mount includes a bearing bracket extending laterally from the frame shaft to a bearing receiving a portion of a cutter and maintains the received cutter oriented at the first angle during rotation. The cutter has a head forming a portion of drive joint for coupling the cutter to a drive shaft. The cutter is received in the mount at the first angle and the drive shaft forms a second angle with the longitudinal axis less than the first angle.

Abstract: A prosthesis for interfacing with an internal region of a bone of a given structure and function such as a femoral head and/or neck, wherein the internal region of the bone can be an avascular necrotic region. The prosthesis comprises porous filling member for filling a cored channel provided in the internal region of the bone to provide mechanical stability which preserves the function and the structure of the bone and accommodate an ingrowth of healthy vascularized bone tissue into the internal region of the bone. Also, a method for mechanically stabilizing a bone using the prosthesis.

Abstract: An oblong acetabular cup which includes a cavity for receiving a bearing element is provided. The plane of the opening into the cavity is skewed relative to the prosthesis' longitudinal plane so as to achieve adduction correction, anteversion correction, or both adduction and anteversion correction. In certain preferred embodiments, the prosthesis is constructed from two components which can be oriented with respect to one another to achieve different directions and amounts of anteversion correction. In some embodiments, the two components form a cusp in the outside surface of the prosthesis. Surgical instruments and surgical methods for implanting the prostheses are disclosed.