A system for a knee arthroplasty procedure comprising: an instrument comprising: a body defining a receptacle therein having an opening at a distal end portion of the instrument; a plunger moveably disposed within the body and moveable between a first position and a second position; a detent moveable by the plunger, such that with the plunger in the first position at least a portion of the detent extends into the receptacle and with the plunger in the second position the detent is recessed from the receptacle; and a collar disposed about at least a portion of the body and moveable relative to the body to operatively actuate the plunger from the first position to the second position characterised in that the system further comprises one or more components (100, 200, 300) configured for insertion into a knee joint during the knee arthroplasty procedure, wherein each of the one or more components have a projection (106, 212, 310) configured to insert in the receptacle of the instrument, the projection further having a recess (108, 312) configured to receive the detent therein to couple the instrument with the one or more components, wherein a distal tip of the body comprises an engagement feature configured to engage the bone and provide a proximal/distal stop for the instrument. an instrument comprising: a body defining a receptacle therein having an opening at a distal end portion of the instrument; a plunger moveably disposed within the body and moveable between a first position and a second position; a detent moveable by the plunger, such that with the plunger in the first position at least a portion of the detent extends into the receptacle and with the plunger in the second position the detent is recessed from the receptacle; and a collar disposed about at least a portion of the body and moveable relative to the body to operatively actuate the plunger from the first position to the second position characterised in that the system further comprises one or more components (100, 200, 300) configured for insertion into a knee joint during the knee arthroplasty procedure, wherein each of the one or more components have a projection (106, 212, 310) configured to insert in the receptacle of the instrument, the projection further having a recess (108, 312) configured to receive the detent therein to couple the instrument with the one or more components, a body defining a receptacle therein having an opening at a distal end portion of the instrument; a plunger moveably disposed within the body and moveable between a first position and a second position; a detent moveable by the plunger, such that with the plunger in the first position at least a portion of the detent extends into the receptacle and with the plunger in the second position the detent is recessed from the receptacle; and a collar disposed about at least a portion of the body and moveable relative to the body to operatively actuate the plunger from the first position to the second position characterised in that the system further comprises one or more components (100, 200, 300) configured for insertion into a knee joint during the knee arthroplasty procedure, wherein each of the one or more components have a projection (106, 212, 310) configured to insert in the receptacle of the instrument, the projection further having a recess (108, 312) configured to receive the detent therein to couple the instrument with the one or more components, wherein a distal tip of the body comprises an engagement feature configured to engage the bone and provide a proximal/distal stop for the instrument.