Patent ID: 8449619

Claim:
A hip stem instrument comprising: a first portion substantially in the form of a stem with a first formation attached to the first portion and a second portion formed as a single piece having a body extending from a first end to a second end, the second end defining a resilient arm, the first and second portions being releasably and directly connected together by cooperation of the first formation and the second end, the first formation having a first ramp surface and being attached to the first portion, the resilient arm having a second ramp surface, the second end being at least partially bifurcated and forming first and second forks, the resilient arm forming the first fork of the second portion, and the first formation being received between the resilient arm and the second fork of the second portion, wherein the resilient arm moves from a first position when the first and second ramp surfaces initially engage, through a range of second positions corresponding to the second ramp surface slidably and progressively ramping along the first ramp surface, to a third position wherein the second ramp surface clears the first ramp surface and drops into a ridge provided on the first formation such that the first formation is received and firmly connected between the resilient arm and the second fork of the second portion, the first portion having a first planar guide surface and the second fork of the second portion having a second planar guide surface, wherein the first and second planar guide surfaces slidably engage while the resilient arm moves through the first, second, and third positions, the first planar guide surface being substantially transverse to a longitudinal axis of the first portion.