Posterior approaches remain among the most used to perform lumbar interbody fusion (LIF) surgery. It happens because of the advantage of providing direct access to the neural elements in the lumbar spine and the surgeons' preference for the approach. But the interbody fusion devices (IFD) inserted using posterior approaches are of limited size, and implant subsidence remains the most common complication after LIF surgery. It can be catastrophic for the patient resulting in worse outcomes or even requiring revision surgery. Since increasing the cage's size is not possible in PLIF surgeries, this thesis will explore biomechanical strategies to increase the load distribution across the IFD and reduce the risk of subsidence. It will be done using patient-specific devices, matching the bony endplate anatomy, manufactured through rapid prototyping and exploring the role of the bone graft housed inside the cage to increase load sharing