Bone is a dynamic tissue that adapts its outer shape and inner microstructure in response to chemo-mechanical environmental stimuli, resulting in alterations in trabecular architecture, apparent density, and material properties. This study employs a poroelastic framework based on the approach of Esposito et al. (2022), which integrates time-dependent load-induced stress stimuli into a biomechanical model that accounts for the role of the fluid content, to predict bone density mapping in a patient undergoing primary Total Hip Arthroplasty and to evaluate the mechanical performance and the lifespan of the prosthesis. The patient underwent CT scanning twice: 24 h (24H) and at 52 weeks post-surgery (1Y). CT data were meticulously realigned to facilitate a point-by-point comparison of bone density distributions. Two in silico models were constructed based on the 24H CT data: one featuring an optimized hip prosthesis and the other with the original implant design. A refined mesh was utilized in the region of primary interest, i.e., the trochanter zone of the femur, to ensure the accuracy and reliability of density outcomes. Mechanical properties of the bone, both elastic and porous parameters, were derived from Hounsfield Unit values, first converted into bone densities by means of a phantom calibration with known material densities scanned alongside the patients. The models were loaded by forces on the prosthesis cup, reflecting the actions associated with the living daily activities, while constraints were applied at the distal ends. The proposed remodeling process was implemented over a 360-day period, evaluating both optimized and not-optimized prostheses. The density data extracted from the 1Y model served as a benchmark for comparison. Remarkably, within just 24 h, the optimized model exhibits stress stimuli and density rates that were comparable to those at the 1-year mark, hence straightforwardly mimicking the stress environment achieved after a full year of physiological remodeling. Conversely, after 360 days, the density path in the trochanter region for the not-optimized model aligned closely with that observed at 1 year, while the optimized model maintained density levels consistent with the 24-h measurements. This underscores the efficacy of the optimized strategy in preserving bone density over time, illustrating its potential impact on enhancing the longevity and mechanical performance of hip prostheses.