Research progress on the application of multi-cup reconstruction techniques in hip revision surgery for severe acetabular defects

With the increasing number of primary total hip replacements, severe acetabular defects have become a major challenge in revision total hip replacement, particularly Paprosky Type IIC–IIIB defects. Traditional reconstruction methods still have certain limitations in terms of initial stability, bone preservation, and long-term fixation. In recent years, multi-cup reconstruction techniques using modular porous metal acetabular components have been increasingly explored as an alternative approach for the reconstruction of complex acetabular defects. This review aims to summarize research progress on multi-cup reconstruction techniques and examine their clinical applications, potential mechanisms, and future directions. This narrative review summarizes recent basic biomechanical research and clinical studies focusing on multi-cup reconstruction techniques, including their biomechanical and biological mechanisms, classification of assembly configurations, intraoperative implantation strategies, clinical indications, postoperative functional outcomes, complications, and reported outcomes relative to other acetabular reconstruction methods. Available evidence suggests that multi-cup reconstruction may increase host bone–implant contact, facilitate restoration of the hip center of rotation, and provide a mechanical environment potentially favorable for load transfer and biological fixation. Published clinical studies have reported generally favorable short- to mid-term functional and radiographic outcomes after multi-cup reconstruction. However, the existing evidence is predominantly derived from single-center retrospective case series and other low-level observational studies; high-quality prospective comparative studies and long-term follow-up data remain limited. Therefore, the optimal selection of prosthesis configurations, the long-term durability of the constructs, and their role in patients with pelvic discontinuity remain uncertain. Overall, multi-cup reconstruction represents a technically feasible option that may be considered for selected patients with severe Paprosky Type IIC–IIIB acetabular defects when adequate residual host bone and initial fixation can be achieved. Its potential biomechanical and biological advantages remain incompletely established, and further multicenter prospective comparative studies with long-term follow-up are needed to determine its clinical effectiveness and appropriate indications. Future research may also evaluate the potential contribution of digital preoperative planning, AI-assisted decision-making, and patient-specific implants to the individualized application of multi-cup reconstruction.