Abstract:[Objective] To investigate the clinical efficacy of 3D printed guide assisted calcaneal osteotomy in the treatment of Haglundsyndrome. [Methods] A retrospective study was done on 37 patients who received surgical treatment for Haglund syndrome in our hospitalfrom January 2021 to June 2022. According to of doctor-patient communication preoperatively, 17 patients had osteotomy performed withthe 3D printed guide (the guide group), while other 20 patients was with conventional free hand technique (the free-hand group). Clinicaland imaging documents were compared between the two groups. [Results] The guide group proved significantly less than the free-handgroup in terms of operation time [(42.8±4.1) min vs (50.2±4.2) min, P＜0.001] and intraoperative fluoroscopy times [(0.6±0.6) times vs (2.2±0.9) times, P＜0.001], but there was no significant difference in incision length and intraoperative blood loss between the two groups (P＞0.05). All patients were followed up for a mean of (18.3±7.5) months. Compared with those preoperatively, the VAS score and AOFAS scorein both groups were significantly improved at the last follow-up (P＜0.05). At the last follow-up, the guide group was significantly better thanthe free-hand group regarding AOFAS score [(96.5±2.9) vs (94.4±3.3), P=0.047]. As for imaging, the posterior calcaneal angle (Fowler-Philipp angle, FPA) and X/Y ratio in both groups significantly improved at the last follow-up compared with those preoperatively (P＜0.05).Although the FPA and X/Y ratio were not significantly different between the two groups before surgery (P＞0.05), the guide group got signifi-cantly greater FPA than the free-hand group at the latest follow up [(65.6±1.9)° vs (61.8±4.9)°, P＜0.005]. [Conclusion] Compared with tra-ditional free-hands calcaneal osteotomy, 3D printied guide assisted calcaneal osteotomy has better therapeutic effect in the treatment of Ha-glund syndrome, improving surgical accuracy and reducing surgical injury.