Additive Manufacturing (AM) has emerged as a transformative technology for metallic orthopaedic implants, enabling unprecedented design freedom, patient-specific solutions, and architectured porous structures. However, the widespread clinical adoption of AM implants remains constrained by challenges related to mechanical reliability, process variability, and regulatory qualification. This review provides a structured and critical assessment of metal additive manufacturing technologies for orthopaedic applications through a process–structure–property perspective. A comprehensive literature analysis was conducted to examine the relationships between manufacturing processes, material selection, implant architecture, post-processing strategies, and clinical performance. The analysis reveals that Powder Bed Fusion technologies currently dominate orthopaedic applications due to their ability to produce complex geometries and controlled porous structures, although their performance remains strongly dependent on defect control, anisotropy mitigation, and post-processing optimisation. The review further identifies a fundamental trade-off between design freedom and fatigue-critical reliability, particularly in load-bearing implants, and highlights emerging solutions based on AM-specific alloy development, digital twins, and data-driven quality assurance. Overall, this review proposes an integrated process–structure–property–response framework linking manufacturing conditions, microstructural evolution, mechanical reliability, and biological response to bridge the gap between academic innovation and clinically reliable orthopaedic implants, providing a roadmap for the development of next-generation additively manufactured medical devices.