Partial meniscectomies are often performed in patients with tom menisci, possibly leading to degenerative arthritis. Therefore, the efficacy of meniscal replacements in preventing the early onset of arthritis is of interest. A number of biomechanical criteria, including attachment to surrounding structures, material properties, and geometry, may be important for a meniscal replacement to restore normal tibio-femoral contact, and hence be clinically successful. To study the variables associated with a meniscal replacement, a solid model of a human knee joint was constructed from a cadaveric specimen using a non-contacting, laser-based, three-dimensional coordinate digitizing system, accurate to less then 8 microns. The model included both the cortical and trabecular bone, articular cartilage, menisci with their horn attachments, and the surrounding ligamentous structures of the knee. The solid model was discretized into finite elements to compute the contact stress distribution on the tibial plateau under the application of a compressive load. The contact stress distribution was also measured experimentally, using a load application system, in the same knee used to create the model. The development of this model showed that the bones could be modeled as rigid. In addition, differences in contact variables (i.e. maximum pressure, mean pressure, contact area, and location of center of pressure) as large as 19% occurred when rotations other than flexion/extension were constrained. With a linearly elastic and transversely isotropic constitutive relationship for the menisci, an optimization performed on the material parameters and attachments associated with a meniscal replacement, minimized the root mean squared normalized error (RMSNE) in the contact variables to 5.4% between the experimental and model contact behavior. The contact variables were particularly sensitive to the circumferential modulus, axial/radial modulus, and horn stiffness. To limit the RMSNE to less than 10%, a circumferential modulus ranging from 100-200 MPa, a hom stiffness greater than 6000 N/mm and an axial/radial modulus greater than 40 MPa are required. Also, the attachments of the deep MCL and transverse ligament should be restored during surgical implantation of a meniscal replacement. Finally, the contact variables were equally sensitive to changes in parameters describing the transverse and cross-sectional geometry of the menisci. Also, the contact variables were more sensitive to changes in the geometrical parameters of the medial meniscus than changes in the parameters of the lateral meniscus.