Tibial trial insert system

A tibial trial insert system, comprising:

• a bearing component having a superior articulating surface for articulation with a distal femoral surface;
• a plate component having an inferior fixation surface for fixation to a proximal tibia;
• and an adjustment arrangement for adjusting a proximal/distal spacing between the bearing component and the plate component,
• wherein the adjustment arrangement comprises:
• an adjustment device having a superior connector element configured to engage with an inferior surface of the bearing component, an inferior base element adapted to be placed at least indirectly upon a superior surface of the plate component, and having a telescopic mechanism operatively coupled to the connector element and to the base element, wherein the telescopic mechanism is user-operable for adjusting a thickness of the adjustment device;
• and at least one shim configured for insertion between the superior surface of the plate component and an inferior surface of the base element for adjusting a height level of the adjustment device in relation to the plate component.