[Application of 3D printing technology in minimally invasive treatment of Sanders typeⅡ-Ⅲ calcaneal fractures].

Abstract

Objective: To explore clinical efficacy of 3D-printed guide plates combined with expansion screw internal fixation in treating Sanders typeⅡand Ⅲ calcaneal fractures.

Methods: From March 2021 to October 2024, 60 patients with Sanders typeⅡand Ⅲ calcaneal fractures were admitted and divided into 3D printing group and closed reduction group based on different surgical methods. There were 32 patients in 3D printing group, including 28 males and 4 females;aged from 31 to 43 years old with an average of (37.2±4.1) years old;the course of disease ranged from 1.2 to 5.0 days with an average of (3.8±1.8) days;17 patients with typeⅡand 15 patients with type Ⅲ according to Sanders classification;treated with closed reduction with screws using custom-made guides printed by 3D technology in combination with expanders. There were 28 patients in closed reduction group, including 25 males and 3 females;aged from 29 to 41 years old with an average of (36.0±5.3) years old;the course of disease ranged from 2.8 to 4.8 days with an average of (4.1±1.2) days;16 patients with typeⅡand 12 patients with type Ⅲ according to Sanders classification;treated with simple distraction device for closed reduction and screw fixation. Operation time, fluoroscopy frequency, blood loss, the changes in Böhler angle, Gissane angle were compared;preoperative and postoperative calcaneal width of talus, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score at 6 months were compared.

Results: Both groups of patients were followed up for 6 to 10 months with an average of (8.4±0.9) months. There were no complications such as infection, skin necrosis, or non-healing of fractures in either group after operation. Operation time, intraoperative blood loss and fluoroscopy frequency of 3D printing group were (51.2±6.8) min, (22.4±5.3) mL and(18.3±4.2) respectively, which were all better than those of closed reduction group(63.5±8.2) min, (39.6±7.1) mL, (34.5±5.8), and the differences were statistically significant (P<0.05). Preoperative Böhler angle, Gissane angle and calcaneal width of 3D printing group and closed reduction group were[(13.9±6.2)° vs. (12.6±5.8)°], [(150.2±3.8)° vs. (149.3±4.5)°], and [(44.2±1.8) mm vs. (42.8±1.6) mm] respectively;and [(27.5±7.1)° vs. (26.8±6.9)°], [(125.7±2.1)° vs. (123.4±1.5)°], and [(38.2±1.2) mm vs. (37.5±0.9) mm] respectively at 6 months after operation;Böhler angle, Gissane angle and calcaneal width of both groups at 6 months after operation were significantly improved compared with those of before operation (P<0.05). Postoperative AOFAS ankle-hindfoot scores of both groups at 6 months showed significant improvement compared to those of before operation (P<0.05), and there was no statistically significant difference between two groups (P>0.05). According to postoperative AOFAS ankle-hindfoot scores at 6 months, in 3D printing group, outcomes were rated as excellent in 12 patients, good in 20 patients;in closed reduction group, outcomes were rated as excellent in 7 patients, good in 21 patients.

Conclusion: 3D-printed guide plate combined with expansion screw internal fixation for treating Sanders typeⅡand Ⅲ calcaneal fractures has advantages of short operation time, less bleeding, and fewer fluoroscopic examinations. It is conducive to the rapid operation of physicians and reduces trauma and radiation to the patients.