Abstract: BACKGROUND: At present, open reduction and internal fixation and minimally invasive needle aspiration are commonly used in patients with Sanders types II and III calcaneal fractures. However, there is little comparison between the clinical efficacy of the two methods and high-level clinical evidence is still available.
OBJECTIVE: To compare the curative effect of Sanders types II and III calcaneal fractures treated by three-dimensional digital model-assisted minimally invasive needle penetration and tarsal sinus incision and manual reduction and internal fixation with steel plate.
METHODS: From January 2021 to October 2022, 80 patients with Sanders types II and III calcaneal fractures who were treated in the Department of Orthopedics, Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine in Hebei Province were randomly divided into control group (40 cases) and observation group (40 cases). The control group was treated with manual reduction and internal fixation with steel plate through the traditional tarsal sinus incision, while the observation group was treated with a three-dimensional digital model assisted with minimally invasive needle penetration fixation. The operation time, blood loss, hospitalization time and fracture healing time of the two groups were recorded. The changes in Maryland score, AO-FAS score, pain visual analog scale score, quality of life score (SF-36 score), and imaging parameters (Böhler angle, Gissane angle, calcaneal length, width and height) were observed before and 12 months after operation in the two groups. The complications during the follow-up were recorded. 
RESULTS AND CONCLUSION: (1) Operation time, blood loss, hospitalization time and fracture healing time in the observation group were lower than those in the control group (all P < 0.05). (2) The Maryland score, AO-FAS score, SF-36 score, Böhler angle, Gissane angle, calcaneal length and height of the two groups after treatment were significantly higher than those before treatment (all P < 0.05). Visual analog scale score and calcaneal width were significantly lower than those before treatment (all P < 0.05). (3) After 12 months of follow-up, the incidence of complications in the observation group was lower than that in the control group (all P < 0.05). (4) In conclusion, the treatment of Sanders types II and III calcaneal fractures with three-dimensional digital model-assisted minimally invasive needle penetration fixation can significantly improve the operation time, bleeding volume and other perioperative indicators, and can reduce the occurrence of multiple complications. The recovery of ankle function, relief of pain symptoms, and improvement of quality of life are equivalent to traditional therapy.

Key words: three-dimensional digital model, minimally invasive needle penetration, traditional treatment, Sanders, calcaneal fracture