Apparatus and method for gauging and controlling process steps used to remove prosthetic joints

Claim 1

A kit for removing a mantle of cement having an elongate cavity formed therein from adhered condition within a bone recess, said kit comprising; (a) a die for forming an elongate screw threaded passage within a mass of cement injected into the cavity; (b) a first elongate pulling element of a predetermined length, said element having a screw threaded section complemental with a screw threaded passage formed by the die; (c) a second elongate pulling element of a predetermined length, said second element having a screw threaded section complemental with a screw threaded passaged formed by the die; (d) torque transmitting means on said first and second elements to enable said elements to be screwed into threaded engagement with a threaded passage formed in a mass of cement by the die; (e) indicator means operatively associated with the screw threaded section of the first element to indicate when the extent of the threaded engagement of said section with the passage has reached a predetermined limited extent and enable the extent of such threaded engagement to be controlled to prevent overtightening of said element in the passage; (f) grippable means on said first and second elements to enable pulling forces to be applied thereto to remove a mass of cement threadably engaged by the screw threaded sections of the elements from a bone recess; and, (g) a gauge for measuring the length of the screw threaded passage comprising an elongated rod having a diameter less than that of the screw threaded passage and a length greater than that of said passage, a tube slidably disposed around the rod having a distal portion of a cross-section greater than the diameter of the threaded passage; and (h) indicia means operatively associated with the rod and tube to indicate the longitudinal position of the tube relative to the rod.