ABSTRACT
PURPOSE: To compare the fixation power of the newly devised RSP (rigid stepped plate) with the L-plate by mechanical study and to prove the efficacy of the RSP. MATERIALS AND METHODS: Lateral closing wedge proximal tibial osteotomy was performed on the 10-monthsold porcine tibiae, which were fixed by 15 L-plates and 15 RSP's. Each group of 5 pairs of the specimen were applied to the Instron apparatus and loaded by compression, valgus, and varus bending. The fixation power was compared by the stiffness of each construct. RESULTS: Specimen fixed by the RSP's showed larger stiffness than those fixed by the L-plate. Even though the difference was not statistically significant in compression (p=0.465), it was statistically significant in valgus (p=0.047) and varus (p=0.009) bending. CONCLUSION: The RSP can be applied with minimal skin incision, will provide firm initial fixation to the osteotomy site, and seems to enable early range of motion exercise. It will improve the outcome of proximal tibial osteotomy by preventing excessive soft tissue dissection and complications resulting from long-term immobilization of the knee joint.