Objective:To evaluate the clinical outcome of 3D printing titanium cage combined with Masquelet technology for the treatment of calcaneus infective defect.Methods:Data of 5 cases with chronic calcaneus infectivedefect treated with regional flap, 3D printing titanium cage combined with Masquelet technology with rib autograft from January 2017 to January 2019 were retrospectively analyzed. There were 3 males and 2 females, with an average age of 37 years old (range, 17-52 years). The mechanism of the five patients included two motor vehicle incidents, two high fall injuries and one rolling compaction. All patients were treated by two-stage procedures. First stage included debridement, polymethyl methacrylate (PMMA) filling and regional flap coverage. The soft tissue defect of the 5 cases included 10 cm×8 cm in 2 cases, 8 cm×7 cm, 8 cm×5 cm, and 5 cm×3 cm each in one case. Bone defect included 4 cm×3 cm×2 cm in two cases, 3 cm×3 cm× 2 cm in two cases and 3 cm×1 cm×1 cm in one case. Second stage was 3D printing titanium cage combined with masquelet technology of rib autograft. Time of bone union, morphology of calcaneus, position of implant, Maryland score and AOFAS hind foot score were recorded to evaluate the clinical outcome.Results:All five patients were followed up for an average time of 18.2 months (range, 12-30 months). Infection happened in one patient 2 months after first stage operation and successfully treated by debridement and PMMA replacement. Incision of the rest 4 cases all healed successfully. Germiculture of the five cases included Methicillin-resistant Staphylococcus aureus (MRSA) in three cases, Staphylococcus epidermidis in one case and Bacterium coli in one case. All five patients got calcaneus bone union after second stage operation. The average time for bone union was 4.32 (range, 3-8) month. Bone trabecular were observed in CT scan 13 (range, 10-22) month post-operation. Average Maryland score in 12 months post-operation was 92 (range, 86-98) and average AOFAS ankle hind foot score was 89.8 (range, 83-100).Conclusion:3D printing titanium cage and Masquelet technology maybe an effective treatment for calcaneus infective defect.