The menisci are fibrocartilaginous tissues that are crucial to the load-sharing and stability of the knee, and when injured, these properties are compromised. Meniscus replacement scaffolds have utilized the circumferential alignment of fibers to recapitulate the microstructure of the native meniscus; however, specific consideration of size, shape, and morphology has been largely overlooked. The purpose of this study was to personalize the fiber-reinforcement network of a meniscus reconstruction scaffold. Human cadaveric menisci were measured for a host of tissue (length, width) and subtissue (regional widths, root locations) properties, which all showed considerable variability between donors. Next, the asymmetrical fiber network was optimized to minimize the error between the dimensions of measured menisci and predicted fiber networks, providing a 51.0% decrease (p = 0.0091) in root-mean-square (RMS) error. Finally, a separate set of human cadaveric knees was obtained, and donor-specific fiber-reinforced scaffolds were fabricated. Under cyclic loading for load-distribution analysis, in situ implantation of personalized scaffolds following total meniscectomy restored contact area (253.0 mm2 to 488.9 mm2, p = 0.0060) and decreased contact stress (1.96 MPa to 1.03 MPa, p = 0.0025) to near-native values (597.4 mm2 and 0.83 MPa). Clinical use of personalized meniscus devices that restore physiologic contact stress distributions may prevent the development of post-traumatic osteoarthritis following meniscal injury.