[Application of three dimensional printed personalized guide plate assisted arthroscopic ankle arthrodesis in the treatment of ankle arthritis]

Objective: To compare the efficacy of conventional open ankle fusion and three dimensional(3D) printed guide plate assisted arthroscopic ankle fusion. Methods: A retrospective cohort study was performed on 256 patients with advanced traumatic ankle arthritis, who were admitted to the Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from May 2018 to February 2023 and underwent ankle fusion procedures. The study cohort comprised 119 males and 137 females, with an age of (59.6±9.5) years (range: 37 to 83 years). Among them, 175 cases underwent internal fixation with plates and screws (58 cases through the combined medial and lateral approach, and 117 cases through the simple lateral approach), 48 cases underwent internal fixation with screws through the anterior approach (conventional open group), and 33 cases underwent minimally invasive arthroscopic ankle fusion assisted by 3D printed guide plate (3D printed guide plate arthroscopy group). Propensity score matching was employed to achieve a 1∶1 match(caliper value=0.02) between the baseline characteristics of patients in the 3D printed guide plate arthroscopy group and the conventional open group. Perioperative and follow-up data between the two groups were compared using the t-test, Mann-Whitney U test, Wilcoxon signed rank test,χ² test, or Fisher's exact probability method, as appropriate. Results: Matching was successfully achieved with 20 cases in both the 3D printed guide plate arthroscopy group and the conventional open group, and there were no statistically significant differences in baseline characteristics between the two groups (all P>0.05). The operation time in the 3D printed guide plate arthroscopy group was significantly longer than that in the conventional open group ((88.9±5.6) minutes vs. (77.9±11.7) minutes;t=-2.392, P=0.022), while the frequency of intraoperative fluoroscopies ((1.7±0.8) times vs. (5.2±1.2) times; t=10.604, P<0.01) and length of hospitalization ((5.5±0.9) days vs. (6.4±1.5) days;t=2.480, P=0.018) were significantly lower in the 3D printed guide plate arthroscopy group compared to the conventional open group. The fusion rate was 95.0% (19/20) in the 3D printed guide plate arthroscopy group and 85.0% (17/20) in the conventional open group, with no statistically significant difference between the two groups (χ²=1.111,P=0.605). The fusion time was (12.1±2.0) weeks in the conventional open group and (11.1±1.7) weeks in the 3D printed guide plate arthroscopy group, with no statistically significant difference between the two groups (t=1.607, P=0.116). At the final follow-up, the American Orthopedic Foot and Ankle Society ankle hindfoot scale was (72.6±5.5)points in the 3D printed guide plate arthroscopy group and (70.5±5.8)points in the conventional open group, with no statistically significant difference between the two groups (t=-1.003, P=0.322). The VAS score of the 3D printed guide plate arthroscopy group was (M(IQR)) 1.50 (1.00) points, lower than that of the conventional open group by 3.00 (1.00) points, with statistically significant differences (Z=-3.937, P<0.01). The complication rate was significantly higher in the conventional open group (25.0%(5/20) vs. 5.0%(1/20), P=0.182). Conclusion: 3D printed guide plate assisted arthroscopic ankle fusion exhibited several advantages, including reduced frequency of fluoroscopies, alleviation of postoperative pain, and decreased complications and length of hospitalization.