Authors: XingHe , DeshengChen , Xiaohai Luo , Yumei Ding , Jiaxi Zhang , Jun Li

Abstract

Objective: Reconstruction of large-segment tibial bone defects caused by osteomyelitis or fracture nonunion remains a major clinical challenge in orthopedic surgery, with the core demand of balancing mechanical stability and biological osseointegration. 3D-printed porous tantalum prostheses have emerged as a novel biomaterial for bone defect repair due to their bionic mechanical properties and excellent biocompatibility, and their combination with the Masquelet induced membrane technique (IMT) is expected to improve the therapeutic effect of large bone defects. However, clinical evidence of this combined strategy for tibial defect reconstruction is still insufficient.

Methods: A series of six patients with large tibial bone defects treated in our hospital from December 2021 to December 2023 were retrospectively analyzed, including 1 case of osteomyelitis-induced defect and 5 cases of nonunion-induced defect. All patients received two-stage surgical treatment based on CARE guidelines: Stage I was debridement + vancomycin-loaded PMMA spacer implantation to induce membrane formation; Stage II was implantation of personalized 3D-printed porous tantalum prostheses combined with autologous bone grafting. The average follow-up period was 13.3 months (range, 12–15 months). Preoperative and postoperative lower limb functional scores (HSS, LEFS, AOFAS), radiographic changes, and complication occurrence were recorded and analyzed.

Results: All six patients achieved primary wound healing without complications such as infection recurrence, prosthesis loosening or displacement. Radiographic examination showed progressive new bone formation and creeping substitution at the bone-prosthesis interface, with a bone ingrowth rate of 35% at 12 months postoperatively; all prostheses maintained excellent mechanical stability (displacement <2 mm). The lower limb functional scores were significantly improved compared with preoperative values: HSS score increased from 22.67±11.91 to 95.33±1.50, LEFS score from 22.83±3.12 to 73.17±4.26, and AOFAS score from 32.00±2.82 to 95.17±3.54 (all P<0.01). All patients regained independent ambulation at the final follow-up.

Conclusion: The combination of 3D-printed porous tantalum prostheses and the Masquelet induced membrane technique is a safe and effective strategy for the short-term reconstruction of large tibial bone defects. This approach can achieve reliable early mechanical stability, promote satisfactory osseointegration, and significantly improve lower limb motor function, providing valuable clinical reference for the treatment of such refractory bone defects.

Keywords: 3D printing; porous tantalum; tibial bone defect; Masquelet induced membrane technique; bone reconstruction; osteomyelitis; fracture nonunion