Reconstruction of traumatic proximal femoral bone defects with personalized 3D-printed porous Ti-6Al-4V prosthesis: a case report and literature review

Abstract

Abstract Background Reconstruction of critical-sized proximal femoral defects caused by high-energy trauma remains a formidable orthopedic challenge due to compromised mechanical stability, anatomical complexity, and limited biological integration capacity. Traditional methods (allografts, Ilizarov techniques, vascularized grafts) often fail to address dual requirements of load-bearing and long-term osseointegration. Methods This case report details a 55-year-old male miner with a 111 mm post-traumatic femoral defect following open comminuted fracture. A two-stage protocol was implemented: 1) Initial stabilization via external fixation and defect temporization; 2) Definitive reconstruction using a patient-specific 3D-printed porous Ti6Al4V prosthesis featuring dual-functional design - hollow architecture for autologous/allogeneic bone grafting and optimized screw trajectories mirroring contralateral femoral anatomy. The implant incorporated biomechanical enhancements including microporous inner surfaces (600–700µm pore size, 70–80% porosity) for osseointegration and multidirectional locking screw fixation. This study was approved by our Institutional Review Board, and informed consent was obtained. Results At 49-month follow-up, radiographic evaluation demonstrated complete bony union and extensive bone ingrowth into the porous structure. The patient achieved full weight-bearing with Harris Hip Score of 92 points, resuming occupational activities without implant-related complications. CT confirmed stable osseointegration without loosening or stress shielding. Conclusion This case validates the efficacy of 3D-printed prostheses with integrated biological/mechanical solutions for traumatic femoral defects. Key innovations include: 1) Dual-phase reconstruction: Mechanical stabilization via topology-optimized porous structure + biological integration through bone-graftable chambers; 2) Anatomic precision: Mirror-image modeling combined with calcar femorale-aligned screw trajectories; 3) Long-term durability: 70–80% porosity balancing stress distribution and fatigue resistance. Compared to conventional methods, this approach reduced treatment duration while achieving superior functional outcomes. Future directions should focus on gradient-porosity designs and bioactive coatings to enhance osseoconduction.