3D printed microporous titanium prosthesis for single implantation or combined with free flap for infected bone defects in the limbs: a single-center retrospective cohort study.

[BACKGROUND] This study represents the largest single-center cohort to date evaluating the early- and mid-term safety and effectiveness of a staged reconstructive strategy using 3D-printed microporous titanium prostheses, applied either alone or in combination with free flap reconstruction, for the management of infected bone defects.

[METHODS] Patients treated between January 2019 and January 2025 were retrospectively identified from electronic medical records. Primary outcomes included changes in Visual Analogue Scale (VAS) scores and Lower Extremity Functional Scale (LEFS) scores at 3, 6, and 12 months, as well as at the last follow-up. Secondary outcomes included implant integration, postoperative functional recovery milestones for lower-extremity cases, and complication profiles.

[RESULTS] This study included 80 consecutive patients (54 males, 26 females) with an average age of 47.5 ± 9.3 years and an average follow-up time of 40.8 ± 14.8 months. At follow-up time points of 3 months and beyond, VAS scores significantly decreased compared to preoperative levels ( < 0.0001), and lower extremity LEFS scores significantly improved ( < 0.0001). At 12 months postoperatively, 69 cases (86.3%) were rated as “Excellent” in terms of implant integration. Subgroup analyses demonstrated that both the single microporous titanium group and the combined free flap group experienced significant improvements in pain relief, functional scores, and postoperative lower-extremity functional recovery over time. Eight patients reported complications, including 6 cases of recurrent infection and 2 cases of prosthesis or screw fractures. A history of diabetes and mixed bacterial infections were significantly associated with a higher risk of recurrent infection ( < 0.05).

[CONCLUSIONS] Preliminary evidence suggests that both the single porous titanium group and the combined free flap group exhibited sustained pain relief and continuous improvement in lower-limb function, with relatively low complication rates. Relying on advanced microsurgical techniques to obtain free flaps and implementing stratified treatment for diabetic patients are crucial for orthopedic surgeons.

[SUPPLEMENTARY INFORMATION] The online version contains supplementary material available at 10.1186/s12891-026-09665-5.