Abstract: The invention includes: a locating system; a computer, interfaced to the locating system and interpreting the positions of tracked objects in a generic computer model of a patient's hip geometry; a software module, executable on the computer, which defines the patient's pelvic plane without reference to previously obtained radiological data, by locating at least three pelvic landmarks; and a pelvic tracking marker, fixable to the pelvic bone and trackable by the locating system, to track in real time the orientation of the defined pelvic plane. Preferably, the system also includes a femoral tracking marker, securely attachable to a femur of the patient by a non-penetrating ligature and trackable by the locating system to detect changes in leg length and femoral offset.

Abstract: A surgical instrument includes an elongated cannula having a forward expulsion end and a rearward breach end, arranged to include a bio-compatible material; a drive member arranged to urge the bio-compatible material in a reciprocating motion having two alternating phases; and a directional brake disposed to contact the bio-compatible material. The directional brake has a preferred braking direction for resisting motion of the bio-compatible material. The preferred braking direction of the directional brake is oriented to resist retreat of said material during the retreating phase and to allow advance of said material during the advancing phase, thus producing a net advance of the material to expel it from the expulsion end. The directional brake is disposed nearer to the expulsion end than the breach end of the instrument, to prevent undesired axial compression of the bio-compatible material during ejection.

Abstract: The invention includes: a locating system; a computer, interfaced to the locating system and interpreting the positions of tracked objects in a generic computer model of a patient's hip geometry; a software module, executable on the computer, which defines the patient's pelvic plane without reference to previously obtained radiological data, by locating at least three pelvic landmarks; and a pelvic tracking marker, fixable to the pelvic bone and trackable by the locating system, to track in real time the orientation of the defined pelvic plane. Preferably, the system also includes a femoral tracking marker, securely attachable to a femur of the patient by a non-penetrating ligature and trackable by the locating system to detect changes in leg length and femoral offset.

Abstract: The invention includes: a locating system; a computer, interfaced to the locating system and interpreting the positions of tracked objects in a generic computer model of a patient's hip geometry; a software module, executable on the computer, which defines the patient's pelvic plane without reference to previously obtained radiological data, by locating at least three pelvic landmarks; and a pelvic tracking marker, fixable to the pelvic bone and trackable by the locating system, to track in real time the orientation of the defined pelvic plane. Preferably, the system also includes a femoral tracking marker, securely attachable to a femur of the patient by a non-penetrating ligature and trackable by the locating system to detect changes in leg length and femoral offset.

Abstract: A surgical instrument includes an elongated cannula having a forward expulsion end and a rearward breach end, arranged to include a bio-compatible material; a drive member arranged to urge the bio-compatible material in a reciprocating motion having two alternating phases; and a directional brake disposed to contact the bio-compatible material. The directional brake has a preferred braking direction for resisting motion of the bio-compatible material. The preferred braking direction of the directional brake is oriented to resist retreat of said material during the retreating phase and to allow advance of said material during the advancing phase, thus producing a net advance of the material to expel it from the expulsion end. The directional brake is disposed nearer to the expulsion end than the breach end of the instrument, to prevent undesired axial compression of the bio-compatible material during ejection.

Abstract: The invention includes: a locating system; a computer, interfaced to the locating system and interpreting the positions of tracked objects in a generic computer model of a patient's hip geometry; a software module, executable on the computer, which defines the patient's pelvic plane without reference to previously obtained radiological data, by locating at least three pelvic landmarks; and a pelvic tracking marker, fixable to the pelvic bone and trackable by the locating system, to track in real time the orientation of the defined pelvic plane. Preferably, the system also includes a femoral tracking marker, securely attachable to a femur of the patient by a non-penetrating ligature and trackable by the locating system to detect changes in leg length and femoral offset.