A prosthetic trial (20) for a joint prosthesis includes a stem (22) having a proximal section (38) and a distal section (36) for implantation in a bone. A body (24) includes a channel (48) receiving at least the proximal section (38) of the stem (22). A locking mechanism (26,28,30) is at least partially disposed within the body (24). The locking mechanism (26,28,30) is biassed into a locking position in which the mechanism locks the stem (22) within the first channel (48) of the body (24). The locking mechanism (26,28,30) is accessible outside said body (24) to be pulled into a releasing position to unlock the stem (22) from the body (24). <；IMAGE>；
