Abstract: Objective To observe the effect of 3D printing-assisted surgery on postoperative functional recovery and bone metabolism index levels of patients with tibial Pilon fracture. 
Methods In total, 87 patients with tibial Pilon fracture in our hospital were selected and divided into 3D printing group (n=43) and conventional group (n=44) according to different treatment plans. The conventional group underwent traditional open reduction and internal fixation with steel plate, and the 3D printing group underwent 3D printing-assisted open reduction and internal fixation with steel plate. The surgical conditions, surgical satisfaction, serum bone metabolism indexes ［bone alkaline phosphatase (BALP), osteocalcin (BGP), tartrate resistant acid phosphatase-5b (TRACP-5b), β isomer of C-terminal telopeptide of type Ⅰ collagen (β-CTX)］ level before operation, at 1 week and 1 month after operation, as well as ankle function score (Olerud-Molander) and visual analogue scale (VAS) for pain before operation, at 6 months and 1 year after operation of the two groups were compared. 
Results The duration of operation and fracture healing time of the 3D printing group were shorter than those of the conventional group, and the number of fluoroscopy and intraoperative blood loss were less than those of the conventional group, suggesting significant differences (P＜0.05). The levels of serum BALP and BGP in the two groups at 1 week and 1 month after the operation were higher than those before the operation, which were higher in the 3D printing group than in the conventional group; The levels of TRACP-5b and β-CTX were lower than those before operation, which were lower in the 3D printing group than in the conventional group, suggesting significant differences (P＜0.05). The Olerud-Molander scores in the two groups at 6 months and 1 year after the operation were higher than those before the operation, which were higher in the 3D printing group than in the conventional group, while the VAS score was lower than that before the operation, which was lower in the 3D printing group than in the conventional group, suggesting significant differences (P＜0.05). The surgical satisfaction of patients in the 3D printing group was higher than that in the conventional group, suggesting significant differences (P＜0.05). 
Conclusion 3D printing-assisted surgical treatment of tibial Pilon fracture has little effect on bone metabolism, which helps to promote postoperative functional recovery and improve patient satisfaction.

Key words: tibial fracture, printing, three-dimensional, ankle joint