A spacer apparatus and method of using the same can be employed to achieve improved fit and balance in a knee joint in knee arthoplasty without requiring multiple cuts to the distal femur or proximal tibia. The spacer apparatus is composed of a biocompatible material in a lattice structure. The spacer apparatus can be pre-selected or pre-shaped, or can be selected or shaped at the time of use to have a thickness and shape appropriate to be used as a spacer to improve knee fit, or as a shim to improve knee balance. The spacer apparatus can be used in connection with a femoral implant, a tibial implant, or both. The spacer apparatus can be shaped to alter the orientation of a femoral or tibial implant in the varus/valgus orientation, the anterior/posterior orientation, or both. The spacer apparatus can be used singly or in combination with other spacer implants to improve fit and balance.
